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The return trip effect: why the trip home always feels shorter than the trip there

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The last time you visited a strange new place, you might have noticed that the return trip home felt quicker than the journey there, even though they were the exact same distance.

It turns out that lots of people experience this illusion — and it can even be replicated in a lab.

The latest evidence for what psychologists call the "return trip effect" is a new study published today in the journal PLOS ONE . In it, Ryosuke Ozawa and other scientists from Kyoto University had participants take simulated "trips" by watching 20-minute videos recorded by a person who'd walked city streets to reach a destination. Compared with those who "took" two one-way trips, round-trippers consistently recalled the second leg taking less time.

The round-trippers went from S to E, then (S) to (E) in the map at left. The control group went from S to E on the left, then S to E on the right. ( Ozawa et al./ PLOS ONE )

We still don't have a clear idea of what causes this illusion. But researchers do have some hypotheses — as well as thoughts on why the conventional wisdom might be wrong.

1) The way back feels more familiar, so it goes by faster

Familiarity is the oldest explanation offered up for the return trip effect — and was first suggested by researchers in the 1950s. There's some logic to it: other research has suggested that experiencing unfamiliar stimuli can make us perceive time as moving more slowly.

But recent experiments indicate this isn't the real reason for the return trip effect. In one 2011 study , researchers had some bike riders take a standard round trip, with the same route there and back. Other riders were instructed to take a different, unfamiliar route back. Surprisingly, both groups judged the return trip as taking less time.

2) We overestimate how long the return trip will take — making it seem quicker

(Getty Images)

Based on his analysis of the 2011 study, Dutch psychologist Niels van de Ven arrived at a different hypothesis. He argued that we often overestimate how long the return trip will take, so that it seems quicker when it actually happens.

"Often we see that people are too optimistic when they start to travel," de Ven told NPR . That means the first leg of the trip takes longer than expected. "So you start the return journey, and you think, 'Wow, this is going to take a long time,'" he said. As a result, the return leg takes less time than expected — and in this context, it feels shorter afterward.

Indeed, in the 2011 study, de Ven found that those who most badly misjudged how long the first leg of the trip would take were most susceptible to the return trip effect.

De Ven's hypothesis might also explain why people don't experience the return trip effect on routes they travel frequently — such as their daily commutes — because their expectations are generally in line with reality.

3) It's because we worry about getting places on time

(Shutterstock.com)

Other researchers have suggested that the return trip effect might occur because we often have a set time that we need to be at a destination, but are less likely to have an exact time we need to be home.

Having an appointment leads our brain to devote more resources to worrying about the time, which makes time seem to pass more slowly. "Returning to the starting point, although it is exactly the same distance, feels in many cases shorter than going there because time is not that important and so our attention is diverted or distracted by events occurring around us," psychologist Dan Zakay has written .

Still, there's lots of evidence to contradict this hypothesis. People report experiencing the return trip effect even when they're traveling for leisure — in which, presumably, getting to the destination isn't an urgent matter — or even if they have a time they need to be home. And in the new study, the participants weren't told they had any specific appointment to make — but still felt the illusion.

4) The return trip effect has something to do with hindsight and storytelling

The authors of the most recent PLOS ONE study don't have a specific explanation for the return trip effect, but they did notice something interesting going on among the people experiencing it.

The study participants were repeatedly asked to report, without looking at a clock, when they thought three minutes had passed as they watched the simulated trip movies. By this measure, both groups — those who took a round trip and those who did two one-way trips — perceived time to be passing at the same rate during the experiment.

It was only afterward, when they were asked to compare the two trips in retrospect, that the differences emerged.

Our brains keep track of time using very distinct systems

This gets at the fact that, as other research has shown , our brains appear to keep track of time using very distinct systems. One mathematically tracks the passage of time in the moment, with neurons that fire at specific rates and mechanisms that record how many times they've pulsed in a given period. Another, more language-based system looks back at previous events and tells stories about how long they took.

Because the illusion only showed up when the participants considered the trips in retrospect, it appears this second system was the one fooled by the return trip effect. The authors of the PLOS ONE study speculate that this may have happened because the participants were explicitly told they were taking a round trip — rather than any factors actually involving the actual route they took. For some unknown reason, the explicit awareness that it was a round trip may have altered their retrospective judgment of the passage of time.

The researchers would like to check this hypothesis by repeating the same experiment without using the phrase "round trip." But another study from 2011 provides some evidence it might be true. In it, participants watched dots move across a screen in a way that simulated movement, much like the old Windows 98 space screensaver :

( MSDOS5.tumblr.com )

Some of them were told they were "traveling" from Fukuoka, Japan, to Paris and back; others were going from Fukuoka to Paris to London. Even in this utterly unrealistic, simplified setting, only those told they were taking a round trip perceived the first leg as taking longer.

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Why the trip home seems to go by faster.

Does getting home from your vacation spot always seem to take less time than getting there? A new scientific study provides an explanation for why. Harold M. Lambert/Lambert/Getty Images hide caption

In 1969, astronaut Alan Bean went to the moon as the lunar module pilot on Apollo 12. Although the trip going to the moon covered the same distance as the trip back, "returning from the moon seemed much shorter," Bean says.

People will often feel a return trip took less time than the same outbound journey, even though it didn't. In the case of Apollo 12, the trip back from the moon really did take somewhat less time. But the point remains that this so-called "return trip effect" is a very real psychological phenomenon, and now a new scientific study provides an explanation.

Niels van de Ven, a psychologist at Tilburg University in the Netherlands, says the conventional wisdom is the trip back seems shorter because it's more familiar, so people recognize landmarks. "And that might help to increase the feeling of speed, of how fast you travel," he says.

But that didn't seem right to him. "When I take, for example, an airplane, I also have this feeling, and I don't recognize anything on my way, of course. When I look out of the window, I don't see something I recognize," van de Ven says.

So he decided to do some experiments exploring that feeling. One involved people who were planning to ride their bikes to a fair. He asked each person to ride the same route to the fair. Then he split the participants into two groups. He asked the riders in one group to come home by the exact same route. For the other group, he mapped out a different route, but one that was the exact same length. If the familiarity explanation was right, only the group travelling home by the same route should feel that the trip home was shorter.

When he did the experiment, he found the route didn't matter. Both groups had the same feeling that the return trip was shorter.

Here's what van de Ven thinks is going on: "Often we see that people are too optimistic when they start to travel," he says. So when they finish the outbound trip, they feel like it took longer than they expected. That feeling of pessimism carries over to when they're ready to return home. "So you start the return journey, and you think, 'Wow, this is going to take a long time.'"

But just as initial optimism made the trip out feel longer than expected, this pessimism starting back makes the trip home feel shorter.

"It's really all about your expectations — what you think coming in," says Michael Roy, a psychologist at Elizabethtown College and a co-author with van de Ven on the article describing this effect in the journal Psychonomic Bulletin and Review .

Roy doubts all psychologists will agree with their conclusion that expectation is an important cause of the trip home effect. "But ... we're not saying this is the only cause. There are definitely likely other causes as well," he says.

In fact, there are psychologists who agree with astronaut Bean that the trip home seems shorter because there's less pressure to reach the intended target on time.

"When you have a destination you want to be there on time," wrote Richard A. Block, a psychologist at Montana State University, in an email. "But when you go back home (return trip) it does not matter that much. Thus, when you are going there, your attention is more focused on the target and not distracted." In this case, being distracted makes the trip seem shorter.

It's true that the return home effect is just an illusion, and a better understanding of it might make it go away. But van de Ven says that might not be a good idea.

"In the end, this return trip effect gives you a positive feeling once you get home, so I'm not sure whether you want it to go away."

Kellogg School of Management at Northwestern University

Marketing Sep 1, 2020

How anticipation warps our sense of time, here’s why that trip to disneyland—or to the dentist—seems to take ages, but the return trip feels much faster..

Ryan Hamilton

Derek D. Rucker

Yevgenia Nayberg

Earlier this year, Derek Rucker and his family visited Disneyland. Their hotel was a quick walk from the happiest place on Earth—a trip that took the same amount of time whether they were arriving or leaving. But that’s not how it felt.

“When we were walking to the park, I thought, wow, it’s taking a long time to get there,” Rucker recalls. “When it was time to go home, I remember turning to my wife and saying, ‘Wow, our hotel is really close.’”

Many of us have likely experienced the logic-defying sense of an outbound trip seemingly taking much longer than the same trip in reverse. (This writer vividly recalls the car ride to the SATs—arguably the opposite of Disneyland—stretching on forever, while the trip home went by in a snap.)

The feeling is so common, in fact, that psychologists created a name for it: the return trip effect, or RTE. But they didn’t know exactly what caused it, and they were curious. After all, the perception of time is an important element of our social environment, and influences behavior in ways big and small. Will you find time for that workout or doctor’s appointment? It depends, in part, on how long you imagine it will take.

In 2011 a group of researchers proposed one idea: perhaps the RTE is caused by greater familiarity with our homes as compared to our destinations. Because we know our house and neighborhood so well, “home” seems to take up a greater geographical area in our minds. As a result, it takes a long time to feel that we are away from home and that a trip is well underway.

Yet, we sometimes experience the RTE even when both the point of origin and the destination are familiar. So something else must be going on, reasoned Rucker and his collaborators— Zoey Chen of the University of Miami and Ryan Hamilton of Emory University.

The something else? Anticipation. In a new paper, the researchers show that the return trip effect is strongest when people have a powerful sense of anticipation about their destination—whether that anticipation is positive or negative: Disneyland or the SATs.

Testing the Anticipation Hypothesis

In an initial study, Rucker and his coauthors created a simple survey that recruited 117 online participants and asked them to recall a recent short trip from home.

Participants estimated how long it took to reach their destination and how long it took to return home. Participants also rated how excited they felt about the destination.

Results showed that participants, on average, estimated their outbound trip took 10 percent longer than their return trip. That suggested people experience a modest return trip effect much of time. Importantly however, this discrepancy increased with excitement about the destination: the greater the excitement, the researchers found, the greater the RTE.

The (Virtual) Return Trip Effect

Some aspects of the first study made it difficult for the researchers to be certain that anticipation was causing a RTE: maybe it really did take longer for participants to arrive at their destination than to return home.

So the researchers found a way to hold the length of both legs of the “trip” constant. In a second study, participants waited to arrive at a virtual destination—a web page.

Of course, waiting for a web page to load is different from in-person travel, but Rucker expected to see the same forces at work. “The return trip effect isn’t really about physical distance. It should be generalized to other situations—any kind of experience that involves waiting for time to pass,” he says.

“[O]ur work suggests that psychological states and environmental cues change how consumers perceive the passage of time.” — Zoey Chen

The researchers randomly assigned 195 participants to one of two conditions. A “high-anticipation group” was told they would be watching a funny, widely liked video, which ended up being a Saturday Night Live sketch. A “low-anticipation group” was told they’d be seeing a boring, generally disliked video, which ended up being about accounting software.

Both groups saw 15 seconds of an animated spinning wheel meant to simulate a video loading (the virtual “outbound” trip), followed by their video. After watching the video, another spinning wheel appeared for 15 seconds (the virtual “inbound” trip), followed by a survey.

Participants were asked to estimate how long it took for both the video and the survey to load. They also indicated how much they expected to like the video—a measure of anticipation.

Not surprisingly, participants who expected to see a funny video rated their anticipation higher than those expecting a boring video. What’s more important, the researchers saw a stronger RTE in the high-anticipation group than the low-anticipation group. The high-anticipation group estimated the “outbound” trip to take an average of 14.81 seconds and the “inbound” trip to take just 10.18 seconds. The difference was smaller in the low-anticipation group: an estimated 12.36 seconds on the outbound journey and 10.46 seconds on the return trip.

Valence or Anticipation?

But the study left the researchers with a question: What if the feeling of positive excitement participants felt while waiting for the funny video to load explained the result? In other words, was the return trip effect related to valence—the emotional tone of the experience—or anticipation?

“It’s a call for researchers to pay greater attention to how consumers understand or perceive the passage of time in their environment.” — Prof. Derek Rucker

So they designed an experiment that evoked a sense of negative anticipation. The study was similar to the previous one, except that all participants saw the same video—an art film—but were lead to have different expectations. Everyone was told that the video was disliked by others; half were then told the video was boring (low anticipation), and the rest were told it was odd (high anticipation).

Once again, the high-anticipation group thought the loading time was longer before than after the video—even though they were expecting to dislike the video. They estimated a load time of 19.96 seconds before the video and 9.68 seconds after it. The low-anticipation group estimated a loading time of 14.45 seconds before the video and 12.85 seconds after it.

Good or Bad, Anticipation Is Key

For the final experiment, the researchers returned to their original setup, asking 410 online participants to estimate how long an actual trip to and from an event had taken. But this time, participants were randomly assigned to recall one of four kinds of events: a positive and highly anticipated event; a positive but not very anticipated event; a negative and highly anticipated event; and a negative but not very anticipated event.

All participants were then asked, “Do you feel it took longer to get to your destination or to return home?” They rated their answers on a scale from one to seven, with seven indicating a greater return trip effect.

The results again suggested that regardless of whether the event is positive or negative, anticipation magnifies the return trip effect. Participants in both the negative and positive high-anticipation groups exhibited a greater RTE than their low-anticipation counterparts.

The research pins down the role that anticipation plays in explaining a long-observed but somewhat-mysterious phenomenon. More broadly, it offers new insights into how we experience time, reinforcing just how malleable and contextualized our perception of it is.

Given how important time is to busy consumers—whether we’re standing in a checkout queue, waiting for an app to load, or waiting for a package delivery—companies might benefit from thinking about how their consumers experience time and how they prefer to think about time. (For instance, Kellogg operations professor Robert Bray has found that customers prefer to get delivery updates later as opposed to earlier in the delivery process.)

Rucker hopes more research will investigate this topic. “It’s a call for researchers to pay greater attention to how consumers understand or perceive the passage of time in their environment,” he says.

Coauthor Chen shares a similar view. “We often think of time as objective and fixed—60 seconds is, and should feel, longer than 59 seconds. But our work suggests that psychological states and environmental cues change how consumers perceive the passage of time. More research is needed to unpack and identify other relevant variables that influence time perception.”

Until then, you can plan experiencing long outbound trips—whether to the lake house or the dentist office—and speedy journeys home.

Sandy & Morton Goldman Professor of Entrepreneurial Studies in Marketing; Professor of Marketing; Co-chair of Faculty Research

About the Writer Susie Allen is a freelance writer in Chicago.

About the Research Chen, Zoey, Ryan Hamilton, and Derek Rucker. 2020. “Are We There Yet? An Anticipation Account of the Return Trip Effect.” Social Psychology and Personality Science.

Related How Much Is Your Customer’s Time Worth? When Do We Identify with the Bad Guy? Stories Can Be Powerful Persuasive Tools. But It’s Important to Understand When They Can Backfire.

The trip back home often seems to go by faster -- but why?

Pedestrians walk through a London Underground station in May. On a round-trip voyage, it often seems like the journey home goes faster than the outbound leg. Using movies of walking trips, scientists in Japan made an effort to figure out why that is.

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You may have noticed it the last time you went on a long journey -- by foot, by car or by plane: the outbound portion of your trip seemed to take a lifetime, while the (more or less identical) leg that brought you home felt like it flew by.

Scientists have noticed this “return trip effect” too, and are beginning to hone their understanding of why we experience it.

In past years, researchers have suggested that it has to do with the way our bodies experience and measure time as it passes, or the way we remember the trips we take after the fact, or perhaps a bit of both. On Wednesday, a team in Japan released a new report in the journal PLOS ONE detailing the latest effort to solve the mystery. This group’s take? That the return trip effect is created by travelers’ memories of their journeys -- and those memories alone.

“The return trip effect is not a matter of measuring time itself. Rather, it depends on time judgment based on memory,” said Ryosuke Ozawa of the Dynamic Brain Network Laboratory at the Graduate School of Frontier Biosciences at Osaka University.

To test out what is going on when the trip home seems shorter, Ozawa and colleagues, then at Kyoto University, created an experiment in which 20 healthy men, between 20 and 30 years of age, watched varying combinations of movies filmed by an experimenter who held a camera in front of the chest while walking two different routes. Half of the group viewed an outbound and return roundtrip on a single route; the other half, walking videos of two different routes in separate locations.

The videos were all approximately 26 minutes long, and the participants viewed them in individual sessions, seated in a chair. Researchers asked test subjects, who were not allowed to have access to clocks, to tell them each time they thought three minutes had passed, and monitored subjects’ heart activity electrocardiograms to assess whether the autonomic nervous system plays a role in the effect. The team also administered a questionnaire at the end of the two movies to see if participants perceived that one trip took longer than the other.

In the end, only that last test -- the after-the-fact questionnaire -- revealed strong evidence of the return trip effect.

“During the initial and return trip, [participants] do not seem to experience the passing time any differently, but when asked afterwards, they have a strong feeling that the return trip felt shorter than the initial trip did,” explained psychologist Niels van de Ven, of Tilburg University in the Netherlands, who has studied the return trip effect in the past but was not involved in Ozawa’s research.

In an email, Van de Ven told the Los Angeles Times that he thought the new study supported his own finding that the return trip effect originates from “a violation of expectations.”

“People are often too optimistic about an initial trip after which it [feels] quite long,” he said. “When heading back we think, ‘It’s going to take a long time again,’ after which it feels not as bad.”

Or perhaps the return trip effect exists simply because people believe it does and respond in kind, he speculated.

Ozawa said he would like to examine the effect in further detail -- analyzing what happens when a filmed traveler returns to his original station via a different route, for instance. He said he had experienced the phenomenon himself during daily activities and had wanted to know more about it for many years.

For more on science and health, follow me on Twitter: @LATerynbrown

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Why the Trip Back Always Feels Shorter

We’ve all felt it before: for whatever reason, the trip coming home seemed a lot quicker than the trip going there. This isn’t just you losing your already tenuous grip on reality; on the contrary, several studies have confirmed the existence of what researchers call the “return trip effect.” Even when travel distance and time are the same there and back, the back feels measurably shorter.

Exactly why this effect occurs is a source of ongoing inquiry. Eryn Brown at the L.A. Times reports on a new study in PLOS One offering one potential explanation: it’s not that we’re bad at judging how long a trip is taking, it’s that we’re bad at remembering how long it took. That’s what the researchers found when asking study participants to watch a video of a round-trip then asking them to judge its length in real-time and retrospectively.

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Peer-reviewed

Research Article

The Return Trip Is Felt Shorter Only Postdictively: A Psychophysiological Study of the Return Trip Effect

Current Address: Dynamic Brain Network Laboratory, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan; Japan Society for the Promotion of Science, Tokyo, Japan

Affiliation Laboratory of Neurophysiology, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan

Current Address: Japan Society for the Promotion of Science, Tokyo, Japan; Research Center of Health Physical Fitness and Sports, Nagoya University, Aichi, Japan

Affiliations Laboratory of Neurophysiology, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan, Japan Society for the Promotion of Science, Tokyo, Japan

* E-mail: [email protected]

• Ryosuke Ozawa, 
• Keisuke Fujii, 
• Motoki Kouzaki

• Published: June 10, 2015
• https://doi.org/10.1371/journal.pone.0127779
• Reader Comments

15 Jul 2015: Ozawa R, Fujii K, Kouzaki M (2015) Correction: The Return Trip Is Felt Shorter Only Postdictively: A Psychophysiological Study of the Return Trip Effect. PLOS ONE 10(7): e0133339. https://doi.org/10.1371/journal.pone.0133339 View correction

The return trip often seems shorter than the outward trip even when the distance and actual time are identical. To date, studies on the return trip effect have failed to confirm its existence in a situation that is ecologically valid in terms of environment and duration. In addition, physiological influences as part of fundamental timing mechanisms in daily activities have not been investigated in the time perception literature. The present study compared round-trip and non-round-trip conditions in an ecological situation. Time estimation in real time and postdictive estimation were used to clarify the situations where the return trip effect occurs. Autonomic nervous system activity was evaluated from the electrocardiogram using the Lorenz plot to demonstrate the relationship between time perception and physiological indices. The results suggest that the return trip effect is caused only postdictively. Electrocardiographic analysis revealed that the two experimental conditions induced different responses in the autonomic nervous system, particularly in sympathetic nervous function, and that parasympathetic function correlated with postdictive timing. To account for the main findings, the discrepancy between the two time estimates is discussed in the light of timing strategies, i.e., prospective and retrospective timing, which reflect different emphasis on attention and memory processes. Also each timing method, i.e., the verbal estimation, production or comparative judgment, has different characteristics such as the quantification of duration in time units or knowledge of the target duration, which may be responsible for the discrepancy. The relationship between postdictive time estimation and the parasympathetic nervous system is also discussed.

Citation: Ozawa R, Fujii K, Kouzaki M (2015) The Return Trip Is Felt Shorter Only Postdictively: A Psychophysiological Study of the Return Trip Effect. PLoS ONE 10(6): e0127779. https://doi.org/10.1371/journal.pone.0127779

Academic Editor: William J. Matthews, University of Cambridge, UNITED KINGDOM

Received: June 27, 2014; Accepted: April 19, 2015; Published: June 10, 2015

Copyright: © 2015 Ozawa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Data Availability: All relevant data are within the paper.

Funding: These authors have no support or funding to report.

Competing interests: The authors have declared that no competing interests exist.

Introduction

Our perception of time is a guiding force in our behaviors because it is an essential component of cognition and motor performance, representing one of the basic mechanisms of cerebral function [ 1 ]. To deal with time, multiple systems over more than ten orders of magnitude have been developed because we process and use temporal information across a wide range of intervals [ 2 ]. Time perception researchers often separate time into millisecond timing, interval timing including the range of seconds-to-minutes-to-hours, and circadian timing [ 2 ]. In this paper we call timing in the range of minutes-to-hours “real-life” timing in order to highlight its relevance to our daily life. Interval timing is less accurate than other timing ranges [ 2 , 3 ]. Because of this inaccuracy, we experience many odd phenomena related to time perception. For example, when we go from a station to a destination, and return to the same station, the return trip often seems shorter than the outward trip, though the distance traveled and the actual duration of the trips are almost identical. This phenomenon is called the “return trip effect” [ 4 ].

Zakay [ 5 ] discussed this effect from the viewpoint of time relevance, which indicates how important it is in a specific situation to be aware of the passage of time. The higher the time relevance, the more attentional resources will be allocated to time and therefore the longer the estimate of duration. When we have to go somewhere at a certain time for an important event, time relevance is high. On the contrary, when returning to the starting point, time is not so important and time relevance is low. However, two studies directly examining the return trip effect provide other potential explanations. These studies did not include a purpose for the outward trip; therefore, time relevance seemed to be equal between outward and return trips. Ven et al. [ 4 ] confirmed that the return trip effect is frequently experienced in daily life. They also reported that it is not due to an increase in familiarity with a route, but is probably due to a violation of expectations for the durations of trips: the more the participants’ expectations were violated on the initial trip, the more they experienced the return trip effect. Seno et al. [ 6 ] conducted a virtual travel experiment with verbal instructions and examined two factors: one perceptual (optic flow inducing self-motion perception or random dot control condition) and one cognitive (with or without a round trip story). Their results indicate that the return trip effect is induced only when self-motion perception is accompanied by the round-trip story, in other words, by combined perceptual and cognitive factors.

The foregoing studies provide important suggestions about the return trip effect, but there are also some problems. One is that a comparison between the round-trip condition and non-round-trip condition in an environment close to daily experience is needed. Ven et al. [ 4 ] used actual trips, or virtual trips by movies, but they compared only round-trip conditions, without a control condition. Seno et al. [ 6 ] examined the round-trip and non-round-trip conditions, but their experimental environment seems to be far from actuality, and the duration of the task (40 s) was much shorter than real-life trips. Recently, the need for ecologically valid tasks has been discussed [ 7 – 9 ]. To address these issues, we investigated not only the round-trip condition but also the non-round-trip condition by presenting walking movies for relatively long intervals. The duration of a trip in this study was over 20 min, which is closer to typical trip-durations than previous studies. The experimental setup using walking movies is more ecological than that in Seno et al. [ 6 ] and the same as that in Ven et al. [ 4 ]. In one of our unpublished studies, when participants walked on a treadmill during the same experiment setup, they sometimes tried to turn right or left on the treadmill as if they had walked in a real environment. The method of watching a movie presented by a projector in a dimly room seems to have a sufficient sense of immersion, though we acknowledge that watching a movie is different from a real walk. From the viewpoint of duration interval and environment, this study is comparatively ecologically valid.

A second issue is the need for prospective timing for a long real-life interval. Time perception studies are divided into prospective and retrospective timing [ 1 , 10 , 11 ]. Prospective timing is involved in the situation where participants are alerted in advance that timing is an essential part of the task presented, for instance, you are asked to perform arithmetic exercises for a given duration and asked in advance to estimate the duration upon the completion of the interval. This timing depends on attentional processes, as explained by the attentional gate model [ 5 , 7 – 9 , 12 , 13 ]: the attention paid to the duration closes a switch between an intrinsic pacemaker and a pulse accumulator, and time judgment is based on the pulses counted in the accumulator. As a result, the more attention is paid to the duration, the longer time is felt to be. Retrospective timing is the situation where participants are asked an unexpected question about duration, for example, you try to recall how long a film was, or how long it took to talk with friends. Retrospective timing is based on memory processes [ 5 , 7 , 9 , 12 , 13 ], and a larger memory for an event leads to a longer remembered duration. When estimating time, it has been assumed that the amount of segmentation determines the size of a memory as a contextual change model indicates [ 14 , 15 ]: the contextual changes perceived generate temporal referents in memory and we reconstruct the duration of the event based on them. That is, more mental contextual segmentations lead to longer estimation. Ven et al. [ 4 ] used the retrospective paradigm. On the contrary, Seno et al. [ 6 ] used the prospective paradigm, but as mentioned above the duration of the task was very short. Therefore, it is unclear whether the return trip effect is observed in prospective timing for longer, real-life intervals. We adopted two methods of time estimation. One was repeated production of a 3 min interval (RP3), which reflects time perception in real time, or prospective timing. The other method was an 11-point scale reflecting postdictive time perception, or retrospective timing, as it was also used in a previous study [ 4 ]. Using RP3 and an 11-point scale enabled us to evaluate both prospective and retrospective timings within the same experiment. However, it should be noted that we use the terms “time perception in real time” and “postdictive time perception.”

It is important that the return trip effect has been observed when using the verbal estimation method [ 4 , 6 ] and the comparison method [ 4 ]. The estimation method may be a more complex time judgment, because it implies the quantification of duration in time units while the comparison method only requires a comparison between durations [ 8 ]. Regardless of this difference the return trip effect has occurred. In this study, RP3 as the production method and an 11-point scale as the comparison method were used. The production method is compatible with the verbal estimation method [ 1 ]. Based on the observations in previous studies, we hypothesized that the return trip effect would be observed not only in the postdictive rating task but also in RP3.

Studies of time perception have focused on physiological factors such as heart rate (HR), body temperature, or age, as well as perceptual or cognitive factors, in search of fundamental timing mechanisms [ 1 , 10 , 16 ]. Classically the relationship between time perception and body temperature has been well known. The general rationale is that, as increase in temperature facilitates chemical reactions, any physiologically based pulser or oscillator will operate at a faster rate, with decrease in temperature having the opposite effect [ 10 ]. Compared to body temperature, HR may have more complex effects. Jamin et al. [ 17 ] found a linear relationship between time estimation and HR, with underestimation of duration with decreased HR. This seems to be explained by the same rationale as that for body temperature because a decrease in HR may lead to a slower rate of the physiologically based pulser, which can cause underestimation of duration. Lediett & Tong [ 18 ] indicated that increases in HR improved the accuracy of time perception in some participants, but lessened it in other participants, depending on their personality. Though the direction of the effect of HR is unclear, HR can modulate time perception. Moreover, HR can be analyzed in more detail. HR is regulated by the sympathetic and parasympathetic nervous systems; therefore, HR variability (HRV) represented by the standard deviation (SD) includes the influence of both systems [ 19 ]. Analyses such as spectral analysis or the Lorenz plot can separately evaluate these modes of regulation [ 20 – 23 ]. Measurement of HR enables us to use these analyses, which is the advantage over measurement of body temperature.

While these physiological factors that are assumed to underlie timing mechanisms are mainly investigated over relatively short intervals, perception for long intervals is attributed to cognitive processes such as memory or attention. However, it is not denied that physiological factors may also affect time perception for long intervals. HR and HRV seem to be related to cognitive processes as well as autonomic regulation. HR has been found to react to the emotional valences of film clip stimuli while HRV has been found to be related to acoustic startle reflex sensitive to negative stimuli [ 24 ]. It is possible that these physiological responses could not only underlie the oscillator of the internal clock but also modify time perception for long intervals through more complex cognitive processes such as emotion [ 13 , 25 ].

The aims of this study were 1) to compare the round-trip and non-round-trip conditions with a real-life duration and comparatively ecological environment, 2) to identify the circumstances where the return trip effect occurs (i.e., time perception measured in real time or postdictively), and 3) to examine whether autonomic nervous system (ANS) activity contributes to the return trip effect. We hypothesized that the return trip effect would be observed in both RP3 and the 11-point scale, and that differences in ANS activities between the two groups may underlie the return trip effect.

Materials and Methods

Participants.

Twenty healthy males (aged 20−30 years) participated in the study. All participants reported normal or corrected-to-normal vision. The experimental procedures were conducted in accordance with the Declaration of Helsinki and were approved by the Local Ethics Committee of the Graduate School of Human and Environmental Studies, Kyoto University. Participants gave written informed consent according to institutional guidelines.

Procedure and tasks

The experiment consisted of two test sessions: the first trip session and the second trip session. In both sessions, participants were asked to watch a movie recorded while walking. Before each session, they were handed a map of a route they would watch in the movie and instructed to glance at the map during the task as if they actually walked the route for the first time. There were three different movies: movie-1, -2, and -3 ( Fig 1 ). Movie-1 showed a route from “S” to “E” in Fig 1A . Movie-2 showed a route from “(S)” to “(E)” in Fig 1A , which meant that the route was the same as that of movie-1, but the direction of travel was reversed. Movie-3 showed a route from “S” to “E” in Fig 1B , which was completely different from those of movie-1 and movie-2. The durations and distances of the three movies were equal (26.3 min, 1.7 km). A round-trip group, comprising 10 participants, watched movie-1 or movie-2 in each session. A control group, comprising the other 10 participants, watched movie-2 or movie-3 in each session. The order of movies was counterbalanced across participants in both groups. We confirmed that all twenty participants were unfamiliar with the routes they had watched.

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‘S’ on the maps denotes the starting point, and ‘E’ the endpoint for each route. Cyan line represents the routes of movies. (A) A route in movie-1 and -2, with ‘S’ and ‘E’ for movie-1 and ‘S’ and ‘E’ with parentheses for movie-2. (B) A route in movie-3.

https://doi.org/10.1371/journal.pone.0127779.g001

While watching the movie, participants were required to verbally report when they felt it had taken 3 min, and to continue these reports until the end of the movie (repeated production of a 3 min interval task hereafter called RP3 task). After watching the two movies, they were asked which movie they felt was longer on an 11-point scale from −5 (the first was a lot longer) to +5 (the second was a lot longer). They were not informed of this question in advance. Participants were instructed to remove their wristwatch or any rhythmical devices and not to use verbal nor nonverbal counting strategies such as “1, 2, 3…” during the tasks. Before the experimental sessions, there was a practice session in which participants watched a movie, saw a map, and carried out the RP3 task using a route that was different from those used in the test sessions. There was a rest interval of 10 min between sessions.

The experimenter had recorded four movies (movie-1, -2, -3, and the movie used in the practice session) using a camera (EX-F1, HD/30 fps, CASIO, Tokyo) held in front of the chest while walking. We carefully prepared three experimental movies to precisely match their durations. Firstly, an experimenter who would record the movies practiced walking in order to walk with constant speed. Secondly, we preliminarily searched routes to examine the timings when traffic lights change so that we could adjust the frequency of being stopped by red traffic lights. Finally, we shot each movie four to six times. Based on these efforts, we produced movies with well-controlled durations. The movies used in the first and second test sessions were approximately 26.3 min long, and the movie used in the practice session was approximately 9.0 min long. Movies were played back by a PC and presented on a screen by a projector (NP62, NEC, Tokyo) at a size of 0.9 m × 1.5 m. Participants were individually tested in a dimly lit room and comfortably sat on a chair. The distance between the screen and the projector was approximately 2.70 m, and that between the screen and the chair was approximately 3.65 m. At the start of the movie, a stopwatch was started, and the experimenter filmed the session so that the times of participants’ verbal reports could subsequently be confirmed. To obtain heart beats, a bipolar electrocardiogram (ECG) was continuously measured by a precordial lead. The recorded ECG was stored on a computer via 16-bit analog-digital converter (PowerLab 16SP, ADInstrument, Sydney) at a sampling frequency of 1 kHz.

Data and analyses

Two indices were used to evaluate time perception. RP3 represented the objective durations between the start of the movie and the first report, or between a report and the following report produced by participants in the RP3 task. The larger the RP3, the shorter the participant evaluated the past time was because overproduction in the production method equals to underestimation in the verbal estimation method. This index evaluated time perception in real time because it was produced during the experiment. The other index was the 11-point scale. This index of time perception more closely corresponds with our daily experiences. Also the judgment on the 11-point scale was not processed during the tasks because it was unexpectedly asked in the end. Therefore this judgment was constructed after the tasks.

ANS activity was assessed from the ECG data. Detection of each cardiac impulse was triggered by the R wave, and visual inspection was used to search the possibility of extra or missing beats. Then R-R intervals were calculated from these impulses, and were converted into instantaneous HRs. To investigate overall changes in HR, the mean instantaneous HR and the SD of instantaneous heart rates (SD-HR) were calculated. SD-HR is considered to be an index reflecting the activity of the whole ANS, because the SD of HR reflects all cyclic components responsible for variability, and the variance is mathematically equal to the total power in spectral analysis [ 19 ]. To investigate ANS activity in detail, the Lorenz plot was adapted. This is a two-dimensional non-linear plot. When the sequence of the consecutive R-R intervals is expressed by I 1 , I 2 ,…, I n , the Lorenz plot is constructed by plotting I k + 1 against I k . Two components of the R-R fluctuation are calculated from the plots: the length of the transverse axis (T), which is vertical to the line I k = I k + 1 , and that of the longitudinal axis (L), which is parallel with the line I k = I k + 1 . These components are calculated by quadrupling the SDs of the plotted points along its axis. Two autonomic indices were obtained from these components: cardiac vagal index (CVI) is defined as log 10 (L × T) and cardiac sympathetic index (CSI) as L/T. CVI and CSI reflect parasympathetic and sympathetic functions, respectively. This analysis is more sensitive than spectral analysis [ 20 ].

RP3s were averaged within participants in each session. ECG data were separated into segments corresponding to RP3s. Then HR, SD-HR, CVI, and CSI were calculated in each segment and averaged across segments within participants in each session.

To assess the independent and combined effects of RP3, HR, SD-HR, CVI, and CSI, a two-way mixed-model analysis of variance (AVOVA) was conducted with the round-trip and control groups as a between-subjects factor (Group) and the first and second trips as a within-subjects factor (Trip Session). If a significant interaction was found, within-subjects differences were analyzed for each group using two-tailed pair-wise t tests. To assess the 11-point scale, a two-tailed Welch’s t test was used because of the difference of variance mentioned in Results (see also Fig 2B ). Also, a two-tailed one-sample t test was used for each group to judge whether the estimation was significantly biased. Effect size was estimated by using partial eta-squared ( η p 2 ) and Cohen’s d . Pearson correlations between autonomic nervous activities (the change of HR, SD-HR, CVI, and CSI) and time estimates (changes in RP3, and the values of 11-point scale) were investigated in each group. The change in each index was defined by subtracting the value in the second trip session from that in the first trip session. For all statistical calculations, p <. 05 was accepted as significant. In case of multiple comparisons at follow-up analyses, Holm correction was used to control for false positives.

(A) Mean RP3 in each condition, calculated across participants, and (B) mean 11-point scale in each group, calculated across participants. Values are means ± 1SE. RP3, repeated production of a 3 min interval.

https://doi.org/10.1371/journal.pone.0127779.g002

Time estimation

The mean RP3s are plotted in Fig 2A . An ANOVA on RP3 revealed that there was a significant effect of Trip Session ( F (1, 18) = 5.57, p = .03; η p 2 = .24). There was no effect of Group ( F (1, 18) = .13, p = .72; η p 2 = .007) and no significant Trip Session × Group interaction ( F (1, 18) = .84, p = .37; η p 2 = .04).

The mean 11-point scale scores are plotted in Fig 2B . There was an apparent difference in SE between two groups. In the round-trip group the evaluated scores were all negative whereas in the control group the scores included both negative and positive values. Due to this difference we performed a Welch’s t test showing that there was a significant difference between the two groups ( t (12) = −2.92, p = .013; d = −1.31). A one-sample t test showed that the mean score for the round-trip group was smaller than 0 ( t (9) = −6.53, p = 1.1 × 10 −4 ; d = −2.06). In addition, all ten participants produced negative values. The scores on the 11-point scale for the control group did not differ from 0 ( t (9) = .60, p = .57, d = .19).

Autonomic nervous function

Variables related to ANS activities are plotted in Fig 3 . In the round-trip group one participant showed very slow HR (around 55 beats/min) with low variability because he was a skilled sport player, and another showed very fast HR (around 100 beats/min) with high variability, which led to wide distributions of HR and SD-HR within the group ( Fig 3A and 3B ). An ANOVA on HR ( Fig 3A ) revealed that there was no effect of Trip Session ( F (1, 18) = .10, p = .75; η p 2 = .006) or Group ( F (1, 18) = .14, p = .71; η p 2 = .008), and no interaction ( F (1, 18) = .70, p = .42; η p 2 = .04). On SD-HR ( Fig 3B ), there was no effect of Trip Session ( F (1, 18) = 1.77, p = .20; η p 2 = .09) or Group ( F (1, 18) = .77, p = .39; η p 2 = .04), but there was a significant Trip Session × Group interaction ( F (1, 18) = 5.16, p = .036; η p 2 = .22). Two-tailed pair-wise t tests revealed that SD-HR in the second trip session was larger than that in the first trip session for the control group ( t (9) = −3.40, p = .016; d = −.48), and that there was no difference between trip sessions for the round-trip group ( t (9) = .55, p = .59; d = .08). On CVI ( Fig 3C ), there was no effect of Trip Session ( F (1, 18) = .51, p = .48; η p 2 = .03) or Group ( F (1, 18) = 2.30, p = .15; η p 2 = .11), and no interaction ( F (1, 18) = 2.74, p = .12; η p 2 = .13). On CSI ( Fig 3D ), there was a significant effect of Trip Session ( F (1, 18) = 9.47, p = .006; η p 2 = .35), but no effect of Group ( F (1, 18) = .59, p = .45; η p 2 = .03). The Trip Session × Group interaction approached significance ( F (1, 18) = 3.87, p = .065; η p 2 = .18). This interaction was not significant, but t tests showed that CSI in the second trip was larger than that in the first trip session for the control group ( t (9) = −4.130, p = .005; d = −.64), and that there was no difference between trip sessions for the round-trip group ( t (9) = −.70, p = .50; d = −.10).

(A) Mean HR in each condition, (B) mean SD-HR in each condition, (C) mean CVI in each condition and (D) mean CSI in each condition, calculated across participants. Values are means ± 1SE. HR, heart rate; SD-HR, standard deviation of heart rate; CVI, cardiac vagal index; CSI, cardiac sympathetic index.

https://doi.org/10.1371/journal.pone.0127779.g003

Correlations

Correlations between ANS activities and time estimates are presented in Table 1 . A significant correlation between the 11-point scale and the change in CVI was found in the control group ( r = .74, p = .014) ( Fig 4A ). The correlation between the 11-point scale and the change in SD-HR approached significance in the control group ( r = .62, p = .054) ( Fig 4B ). No other significant correlation was found in the control group, and no correlations were found in the round-trip group.

(A) Correlation of the change of CVI with 11-point scale for the control group, and (B) correlation of the change of SD-HR with 11-point scale for the control group. The change was defined as subtracting the value in the second trip session from that in the first trip session. ANS, autonomic nervous system; CVI, cardiac vagal index; SD-HR, standard deviation of heart rate.

https://doi.org/10.1371/journal.pone.0127779.g004

https://doi.org/10.1371/journal.pone.0127779.t001

It should be noted that we cannot be confident of the null results of ANOVA interaction effects mentioned below due to low statistical power. Assuming sample size = 10 per group and medium effect size f = .25 equivalent to η p 2 = .06, the statistical power to detect the interaction = .56 (calculated with G*Power 3.1 [ 26 ]).

Discrepancy between the two time estimates

We assessed time perception in two ways, prospective judgment involving on-going temporal production (RP3) and retrospective judgment comprising a comparison of two intervals on an 11-point scale. These two indices apparently showed different results, suggesting that the return trip effect might be caused only postdictively. According to the 11-point scale results, only the round-trip group estimated that the second trip took less time than the first trip. In contrast, the RP3 results indicate that both groups felt that time had been shorter in the second trip session. Considering that the 11-point scale is a similar method for evaluating time perception to that used in previous research [ 4 ] and is also close to the situation in which we experience the return trip effect in daily life, it is certain that the return trip effect is observed at least postdictively. In addition, this difference between the two time estimates suggests that postdictive time perception, measured by the 11-point scale, might not be based on time perception in real time, as estimated by RP3. During tasks, time may be felt to be shorter in the second trip session for both groups, but this would not lead to the same experience of time after completion of the tasks.

The discrepancy between the two estimates can be explained by timing strategies. Time perception includes prospective and retrospective timing [ 1 , 10 , 11 ]. RP3 would be prospective timing because participants were aware of this task during the experiment, and the production method is a major method in prospective timing. The 11-point scale may reflect retrospective timing because it was conducted unexpectedly and postdictively, though participants knew that timing was a major task because of RP3. One of the purposes of this study was to reveal whether the return trip effect is observed when using prospective timing for a long real-life interval. The absence of the effect in RP3 indicates that the return trip effect is not induced in prospective timing. The difference between our results and Seno et al. [ 6 ] also using prospective timing could be attributed to duration intervals because their stimuli were 40 seconds. In addition to the two timing paradigms, Wearden [ 11 ] proposed another one, passage of time. Different from prospective and retrospective timings, which focus on how long a time period lasted, passage of time concerns how quickly time seemed to pass. By intuition, if time seems to pass quickly during an event, the event might be judged as short. However, Wearden [ 11 ] reported that film clip stimuli which seemed to pass more quickly were evaluated equally in retrospective time estimation. Passage of time may be easily influenced whereas retrospective timing appears to be difficult to manipulate. The return trip effect, which was only observed in the subjective scale judgment, may not be a matter of the duration judgment, but of passage of time. The question in the 11-point scale was “which movie they felt was longer” and the answer was for example “the first was a lot longer.” This subjective scale may have been confused with passage of time. To investigate whether the 11-point scale was confused with passage of time, we should compare the postdictive verbal estimation and the 11-point scale with the same setting as the present experiment.

The absence of interaction in RP3 may reflect the specific timing method rather than the timing strategy. Previous studies have observed the return trip effect when using the verbal estimation and subjective scale methods [ 4 , 6 ], which suggests that the return trip effect can be assessed by both the method requiring quantification and that requiring just comparison [ 8 ]. As the production method used in RP3 seems homologous to the verbal estimation method [ 1 ], we had expected the return trip effect in RP3, but did not observe it. One of the possible differences between the production and the verbal estimation methods is a review of past time. In the production method, participants can predict how long they should pay attention to time because the target duration, 3 min in this study, is presented beforehand. On the contrary, in the verbal estimation method participants do not know how long they will measure time; presented durations may be 10 sec, 10 min, or 1 hour. In this unpredictable situation without counting strategies it may be more or less necessary to postdictively review past time after the task. The return trip effect observed in previous studies [ 4 , 6 ] using the verbal estimation may be attributed to the review of past time. The postdictive 11-point scale in the present study also includes the review of past time, which may imply the importance of the review of past time.

It is worth noting that the increase in RP3 in both the round-trip and the control condition in the second session might be attributable to repeated reports. According to interviews after completion of the tasks, participants initially seemed to find the RP3 task to be difficult, but as they continued they became accustomed to the task and found it easier. In general, the durations of simple or dull tasks tend to be underestimated, whereas complex or detailed tasks tend to be overestimated [ 27 – 29 ]. Another possible explanation for the increase in RP3 is that there is a lag before the participant becomes absorbed by the movie. When playing a video game, players often underestimate the playtime, but when playing the game only briefly, they overestimate the playtime because of an “adaptation period” that is required to be fully immersed in the game [ 7 , 9 , 30 ]. Bisson et al. [ 9 ] discussed that the adaptation period might be less pleasant and thus induce overestimation of time. It is also possible to interpret the adaptation period from an attentional perspective: after this adaptation period, participants can be absorbed in the game, which distracts attention from its duration [ 12 ]. According to a model for apparent duration suggested by Glicksohn [ 31 ], apparent duration is a multiplicative function of the size of and the number of the subjective time unit. Externally oriented attention decreases the size of the time unit. In the present experiment, after an adaptation period in which participants might have been absorbed enough into the movie, more attention might have been deployed to the movie (an external stimulus) thereby decreasing the size of the time unit, and thus apparent duration might have been shortened. If the duration of the practice session is extended to fully elicit the possible habituation to the RP3 task or the possible absorption into a movie in advance, the change in RP3 observed in this study might vanish. Also, if absorption causes overproduction (underestimation) in RP3, RP3 while playing a video game could be increased after a certain adaptation period. These approaches could provide informative evidence about the change of RP3.

As mentioned above, the absence of the interaction in RP3 may reflect low statistical power. The difference between the two groups in the 11-point scale measure was very large, so the return trip effect seems to be prominently observed in postdictive time estimation. However, we can’t be confident of the null results of RP3.

Moderately different influences on ANS

The two experimental conditions did not cause drastic, but only moderately different, changes in overall ANS activity. The whole ANS, as measured by SD-HR, was more active in the second trip session only for the control group. Similarly CSI, reflecting sympathetic activity, increased only for the control group. These results suggest that overall ANS activity differently responded for the two groups, mainly as a result of sympathetic activity. Increased HRV is associated with lower mental load [ 32 , 33 ]. However, the increase in sympathetic activity is considered to reflect an increase in mental stress or concentration [ 34 ]. It is difficult to infer the change in mental state in the control group. However, on the basis of the major contribution of sympathetic activity discussed above, it is possible that the control group might have felt greater mental stress in the second session. Watching one trip movie over 25 min was a lengthy task. During the second session participants in the control group might have felt that they would have to watch another long dull movie. In contrast participants in the round-trip group might have been relaxed because they would know it from past experiences of return trips that the return trip would seem short. Here we emphasize only that the combinations of movie-1 & -2 and movie-1 & -3 had moderately different influences on ANS activity.

Influence of ANS activity on time perception

Time perception, estimated postdictively, seems to be related to the parasympathetic activity. When the change in CVI between the two sessions was larger, participants in the control group felt that the session with larger CVI was shorter. The correlation between the change in SD-HR and the 11-point scale showed the same trend. On the basis of the fact that the parasympathetic nervous system activity represented by CVI contributes to ANS activity represented by SD-HR, and the values of r (.74 and. 62 for CVI and SD-HR, respectively), it can be inferred that among ANS activities the parasympathetic activity mainly contributed to postdictive time perception. A recent study investigating the relationship between body signals and time perception suggests that the parasympathetic activity may affect time perception. In the reproduction method a decrease in HR caused by an increase of the parasympathetic activity during encoding of time improved the accuracy of duration reproduction [ 16 ]. In our study we cannot refer to the accuracy of postdictive time judgment, but the significant correlation between the 11-point scale and CVI may correspond to an improvement of the accuracy of time estimation. Participants may have tended to overestimate the duration, and the parasympathetic activity may have improved the accuracy of time estimation. As a result, the parasympathetic activity shortened time estimation and participants felt that the session with larger CVI was shorter. Contrary to the control group, the change in CVI was not related to the comparative judgment on the 11-point scale for the round-trip group. This indicates that the relationship between postdictive time perception and the parasympathetic activity may not be so robust.

At the end of this section we should represent one concern that the significant and nearly significant correlations out of 16 might well be false positives. In the present study CVI showed the significant correlation with time perception, which in part follows previous research [ 16 ] finding the relationship between time perception and the parasympathetic activity. Moreover, it seems reasonable that CVI and SD-HR showed higher r values because the parasympathetic nervous system composes ANS. So the correlations we found may be genuine. Nevertheless more research is need in this issue.

What causes the return trip effect?

Why does the round trip bias time perception? Ven et al. [ 4 ] reported that the return trip effect was observed not only when the return trip was via the route same as the initial trip, equivalent to our round-trip group, but also via a route different from the initial trip. Seno et al. [ 6 ] found that the return trip effect was induced only when self-motion perception was accompanied by a round-trip story. Though these two studies used shorter durations than the present study (7 min in Ven et al. [ 4 ], 40 s in Seno et al. [ 6 ]), their results both suggest that the fact or the awareness of “return” would be necessary for the return trip effect. Our control group did not have this awareness, which supports this idea. If this awareness is systematically manipulated, conditions necessary for the return trip effect might be found.

To interpret the return trip effect in a clearer way, the experimental design should be improved. The round-trip group watched movie-1 and -2 as a round trip while the control group saw movie-2 and -3 as a non-round trip. Due to this design the two groups were looking at different scenery or objects. We preliminarily searched the numbers of corners, distances, sizes of the roads, and traffic volume in order to match the environments of the routes. However, the scenery of the movies the two groups watched was not completely the same. For future research, one of the ways to solve this problem would be to use two sets of round-trip movies, such as pairs of movie-1 and -2, and movie-3 and -4. This design will enable us to make four round-trips and eight non-round-trips by counterbalancing the order and combination. Using this design, we will be able to compare the round-trip condition and the non-round-trip condition with the same scenery.

Also, the ecological validity could be elevated. We used as stimuli real-life intervals and the projection of walking movies, which seem to provide a sufficient sense of immersion. However, this environment is different from a real walk in some ways, for example, a narrow field of vision or the absence of physical activity. There are few studies relating time perception to physical activity, but physical activity may modulate time perception. It has been reported that physical activity lessened the accuracy and the variability of time perception [ 35 ]. In contrast, Tobin & Grondin [ 8 ] found smaller variability of time perception with physical activity than visualizing that activity. The impact of walking as a physical activity should be investigated by using treadmill or a field study.

We investigated the return trip effect in a comparatively ecologically valid situation over a real-life interval. By comparing the round-trip condition and the non-round-trip condition, it was confirmed that the return trip does actually make us feel that time is shorter. Moreover, our two methods of time estimation suggest that the return trip effect does not affect the timing mechanism itself, but rather our feeling of time postdictively. We also examined whether ANS activity measured by ECG is related to time perception. Parasympathetic function is one of the resources for temporal information, although it is not so robust one.

For future research, it would be interesting to test the contribution of the awareness of “return” because this semantic labeling may be a major factor in inducing the cognitive bias of the return trip effect. Moreover, neuroimaging studies could provide insight into how time is perceived in ecological situations.

Author Contributions

Conceived and designed the experiments: RO KF MK. Performed the experiments: RO. Analyzed the data: RO KF MK. Contributed reagents/materials/analysis tools: RO KF MK. Wrote the paper: RO KF MK.

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Why Does It Take Longer to Go There Than to Come Back?

Anticipation and the return trip effect..

Posted May 25, 2020 | Reviewed by Kaja Perina

We’ve all had the experience of going on a road trip and feeling like we’re never going to get to our destination. And yet, the return trip home seems so much shorter. If you took the same roads and encountered similar traffic conditions, then the time should be about the same. But with the return trip effect, the journey home feels shorter than the outward trip.

The return trip effect has to do with the subjective experience of time. At the biological level, we have a number of internal clocks that are relatively precise. Our hearts beat to a steady rhythm, and our bodies go through daily cycles. And yet at the psychological level, our perception of time is imprecise and greatly influenced by our mood. We’ve all had situations where time seemingly stood still and others when it just flew by. But our ability to judge the actual passage of time is quite limited.

Psychologists have long been interested in the subjective experience of time in general and in the return trip effect in particular. Several explanations for the effect have been offered as well, each with some evidence in support. In a recent article in the journal Social Psychology and Personality Science , University of Miami psychologist Zoey Chen and colleagues offer a novel explanation for the return trip effect, which they test in a series of experiments.

One explanation for the return trip effect involves familiarity. The idea is that the subjective perception of time slows down during unfamiliar experiences. As a result, the outbound journey feels longer than the return trip. However, research shows that the return trip effect occurs even with familiar journeys such as your daily commute.

An alternative explanation is that return trip effect results from a violation of expectations. People often underestimate how long it will take to do something. When they go on an unfamiliar trip, they find the journey takes longer than expected. But on the return trip, they now know how long it will take, so there’s no violation of expectations. Again, the problem is that the return trip effect still occurs with familiar trips. You know how long your commute takes, but still the trip to work seems longer than the trip home.

Chen and colleagues propose a novel explanation for the return trip effect which they call the anticipation account. The researchers start with the observation that the two legs of the journey typically involve different levels of anticipation. You are certainly more excited about going on your vacation at the beach than you are about your return to your humdrum life afterward. And even during your morning commute, you’re usually thinking ahead to all the things you have to do when you get there.

The researchers also point out that there are cases where the return trip effect works in reverse. Imagine you’re at the supermarket when you get an emergency call from a family member. Your trip back home will certainly feel longer than usual.

According to the researchers, anticipation heightens arousal, raising attention and causing us to be more alert. Arousal also produces an apparent time elongation. If you’ve ever been in a serious automobile accident or other highly dangerous situation, you no doubt had the experience of time slowing down.

Recall that the return trip effect is but one instance of the larger phenomenon of the subjective perception of time. So it isn’t necessary for experimental participants to actually go on a journey. Rather, a virtual trip there and back will do just as well to elicit the return trip effect.

In the key experiment that Chen and colleagues performed, participants responded to a series of questions online. They were then told that they were about to leave the current web site to go to another site to watch a short video clip before returning to the survey. Before the video started, a blank screen displaying a spinning circle appeared for 15 seconds. When the video ended, the same spinning circle appeared for another 15 seconds, after which the survey resumed. At the end of the experiment, the participants were asked to estimate how long it had taken the video to load (the outbound trip) and how long it took to return to the survey.

To manipulate anticipation, the participants were given different expectations about the video they were about to watch. Half of the participants were told that the video they were about watch was very funny and that people generally enjoyed it. (In fact, it was a Saturday Night Live sketch.) The other half were told that the video was boring and that most people disliked it. (This time, it was a clip on how to do accounts receivable in QuickBooks.)

If the return trip effect is due to anticipation during the outbound journey, then it should show up in the funny video condition but not in the boring video condition. Essentially, this is what the researchers found. In both conditions, the outbound trip was estimated as longer than the return trip. However, the difference was quite small in the boring video condition but quite large in the funny video condition.

Another interesting finding was that the participants who watched the funny video were quite accurate in their estimation of the duration of the outbound trip. In all other cases, they underestimated the time span. This suggests that when we are in a heightened state of arousal, as for example when we’re anticipating our arrival at our destination, our perception of the passage of time is rather accurate. But when we’re not aroused, we perceive time as passing faster than it actually does.

Other experiments reported in this article, including one in which participants made actual physical trips to other locations, yielded similar results. Overall, they provide strong support for the anticipation account, which posits that our arousal at looking forward to our arrival at our destination causes time to appear to slow down. This, in turn, results in the return trip effect.

The work of Chen and colleagues on the return trip effect opens ample opportunities for further research, and I’m really looking forward to reading more about it. But I know it’s going to feel like an awfully long wait.

Facebook image: Vera Petrunina/Shutterstock

Chen, Z., Hamilton, R., & Rucker, D. D. (2020). Are we there yet? An anticipation account of the return trip effect. Social Psychology and Personality Science. Advance online publication. DOI: 10.1177/1948550620916054

David Ludden, Ph.D. , is a professor of psychology at Georgia Gwinnett College.

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The return trip effect: Why the return trip often seems to take less time

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• Published: 23 August 2011
• Volume 18 , pages 827–832, ( 2011 )

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• Niels van de Ven 1 ,
• Leon van Rijswijk 3 &
• Michael M. Roy 2  

Three studies confirm the existence of the return trip effect: The return trip often seems shorter than the initial trip, even though the distance traveled and the actual time spent traveling are identical. A pretest shows that people indeed experience a return trip effect regularly, and the effect was found on a bus trip (Study 1), a bicycle trip (Study 2), and when participants watched a video of someone else traveling (Study 3). The return trip effect also existed when another, equidistant route was taken on the return trip, showing that it is not familiarity with the route that causes this effect. Rather, it seems that a violation of expectations causes this effect.

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When we return from a conference, the return trip often seems shorter than the initial trip. This is odd, since the distance traveled and the actual time spent traveling are usually identical. Here, we investigated the existence of a return trip effect and explored two possible causes of this phenomenon. If a return trip effect exists, one possible cause might be an increase in familiarity and predictability. Previous research has shown that novel tasks are often remembered as taking longer than they actually do, while familiar tasks are remembered as taking less time (Avni-Babad & Ritov, 2003 ; Boltz, Kupperman, & Dunne, 1998 ; Hinds, 1999 ; Roy & Christenfeld, 2007 ). Similarly, tasks that are unpredictable are remembered as taking longer than similar coherent or predictable tasks (Boltz, 1993 , 1995 , 1998 ). The unpredictability of the initial leg of the trip may make it so that it is remembered as being overly long. Conversely, the return trip is remembered as being short because it is now more familiar and predictable.

Alternatively, the return trip effect could be due to a violation of expectations. People often predict that tasks will take less time than they actually do (Buehler, Griffin, & Ross, 2002 ; Kahneman & Tversky, 1979 ; Roy, Christenfeld, & McKenzie, 2005 ). In general, people are fairly inaccurate when estimating how long things either have taken in the past (Block & Zakay, 1997 ; Burt & Kemp, 1991 ; Poynter, 1989 ; Wallace & Rabin, 1960 ) or will take in the future (Buehler et al. 2002 ; Roy, Christenfeld & McKenzie 2005 ). It may be that people have an expectation for a trip that is overly short, leading to a violation of this expectation when they take the trip. Hence, the initial trip takes longer than expected. For the return trip, the expectation is likely to be based on the experience of the (disappointingly long) initial trip. This leads to an upward adjustment in expectations for the return trip that is, happily, unmet. The return trip, therefore, feels shorter than the initial trip. Here, we try to establish whether or not there is a return trip effect and whether this might be due to a shift in familiarity or expectation.

Before the studies were undertaken, a pretest was conducted to test whether people actually experience this phenomenon in their daily life. Fifty-six students (43 females, M age = 19 years) indicated whether they “sometimes feel that the return trip seems shorter than the initial trip” and whether they sometimes feel that it seems longer, on scales from 1 ( never ) to 7 ( always ). In comparison with the initial trip, participants more often reported that the return trip felt shorter ( M = 5.23, SD = 1.36) than that it felt longer ( M = 3.59, SD = 1.80), paired-sample t (55) = 4.21, p < .001, r 2 = .24. When given a forced choice about whether the initial trip or the return trip tended to feel shorter, participants were almost 3 times as likely to indicate that the return trip tended to feel shorter (73% chose the return trip vs. 27% for the initial trip). Similar to our own experiences, participants felt that a return trip effect occurs frequently. The return trip effect was further examined in a field study ( Study 1 ), a field experiment ( Study 2 ), and a controlled lab experiment ( Study 3 ).

In Study 1 , the return trip effect was tested in a real-world situation, and possible explanations for the phenomenon were explored. Sixty-nine participants (57 females, M age = 33 years) who had just returned from a day trip by bus from either a housekeeping fair (a large event where people received free goods related to housekeeping) or the Efteling (a large theme park) indicated which part of the trip felt longer. We took care to include only participants for whom the initial and return trips actually took the same time (which varied between 25 and 120 min) Footnote 1 and who were awake during both trips. After the return trip ended, the participants indicated how long they felt that the return trip had taken, as compared with the initial trip, on an 11-point scale from -5 ( a lot shorter ) to +5 ( a lot longer ). Participants exhibited a return trip effect, with the return trip feeling like it took less time than the initial trip ( M = -0.55, SD = 2.16, with an average response significantly lower than 0), t (68) = 2.12, p = .04, d = 0.25.

To examine the influence of trip familiarity/predictability on the return trip effect, participants also indicated the extent to which they recognized certain waypoints on the return trip that they had seen on the initial trip on a scale from 1 ( none ) to 9 ( a lot ) ( M = 5.32, SD = 2.15). A regression analysis showed that how much they recognized along the way (as a measure of familiarity) was unrelated to the return trip effect, β = .15, t (67) = 1.21, p = .23; recognizing more waypoints during the return-trip did not influence the perception that the return trip took less time than had the initial trip.

To examine the effect of expectations on the return trip effect, participants indicated whether the initial trip took shorter or longer than they had expected on an 11-point scale from -5 ( much shorter ) to +5 ( much longer ). On average, participants indicated that the initial trip took longer than they had expected ( M = 0.59, SD = 2.27, which differs from 0), t (68) = 2.17, p = .03, d = 0.26. Furthermore, this violation of expectations predicted the return trip effect: The more travelers thought that the initial trip took longer than they had expected, the more they felt that the return trip took less time than the initial trip had, β = -.27, t(67) = 2.25, p = .02.

Study 2 attempted to replicate the findings of Study 1 using a different task. In Study 1 , participants’ familiarity with the return route, as measured by the number of waypoints recognized, did not influence the return trip effect. However, this measure might not have accurately or fully captured their familiarly with the return route. Therefore, the possible role of familiarity in the return trip effect was examined in Study 2 by having participants return either by the same or by a different, equidistant route.

Ninety-three 1st-year students (67 females, M age = 19 years) at a get-to-know-each-other event at the start of the academic year traveled by bike from a base camp (where they had spent one night) to a nearby forest to play some games for about 2 h. Participants traveled in small groups of 5–10 participants and followed someone who knew the way (who was not included in the sample). Participants were randomly assigned to travel along one of two equally long routes on the initial leg of the trip (route 1 = 9.23 km, route 2 = 9.19 km), both of which, in a pretest, took 35 min. A separate group of participants (a control group) traveled the initial leg via route 1 ( n = 10) or route 2 ( n = 8). They were asked at the end of the initial trip how long it had felt to them in minutes. They confirmed that both routes felt equally long ( M route1 = 41.5 min, M route2 = 42.5 min), t (16) = 0.24, p = .83, d = 0.10.

For the main group of participants, we manipulated whether they returned by the same route as that initially traveled ( n = 32) or by the other one ( n = 50). Footnote 2 After participants arrived back at base camp, they filled out a questionnaire measuring their time perceptions of the initial and return trips. All estimates were given after both trips had been completed so that participants on each leg of the trip were unaware that they would be estimating duration (knowing that an estimation will be required can change time perception; Block & Zakay, 1997 ).

We conducted a 2 × 2 mixed-model Type III ANOVA with same route versus different route as a between-subjects variable and time estimate (in minutes) of initial trip versus return trip as a within-subjects variable. Participants exhibited a clear return trip effect, estimating that the initial trip took longer (44.3 min) than the return trip did (36.9 min), F (1, 80) = 19.02, p < .001, η 2 p = .19. Note that the estimates for how long the initial trip took ( M = 44.3 min) did not differ from the estimate of the control group ( M = 41.9 min), who made a time estimate directly after the initial trip, t (98) = 0.78, p = .44, d = 0.16. Even though participants who completed the full experiment gave estimates for the initial leg after a long delay, their estimates did not differ from those of the control group, who estimated duration directly after completing the trip. As further evidence for the return trip effect, how long the return trip felt to participants ( M = 36.9 min) was shorter than the estimate the control group made for how long the initial trip felt ( M = 41.9 min), t (98) = 2.06, p = .04, d = 0.42.

Varying the return route allowed us to directly examine the role of familiarity in the return trip effect. First, there was an unexpected main effect of condition showing that participants who took a different route on the way back made longer estimates for both the initial trip and the return trip (42.3 min on average) than did participants who returned by the same route (38.2 min), F (1, 80) = 5.34, p = .02, η 2 p = .06. Importantly, however, the magnitude of the return trip effect was not significantly different for participants who returned either by the same or by a different route, F (1, 80) = 1.77, p = .19, η 2 p = .02. While a lack of familiarity might have caused participants who returned by novel routes to give longer estimates overall, familiarity with the route did not explain the return trip effect.

As in the previous experiment, participants indicated whether or not the initial trip took longer than they had expected on the scale from -5 ( a lot shorter than expected ) to +5 ( a lot longer than expected ). Participants thought that the initial trip took longer than expected ( M = 1.46, SD = 1.64, which differed from 0), t (89) = 8.19, p < .001, d = 0.89. More important, this violation of expectations again predicted the return trip effect: The more participants thought that the initial trip took longer than expected, the shorter they felt the return trip took, as compared with the initial trip (as measured by the difference in minutes of the estimated duration of the initial and the return trips), β = -.33, t (80) = 3.12, p = .003.

In a final study, the return trip effect was tested in a more controlled setting. To do so, participants watched a video of someone traveling by bike from her home to a friend’s house and back again at a later time. We made the video so that the initial and return trip were of exactly the same length, both in time and in distance traveled. Therefore, for example, different speeds of travel could not influence the time estimates (as found by Cohen & Cooper, 1962 ; Cohen, Hansel, & Sylvester, 1953 ). To further test the hypothesis that the return trip effect is caused by a violation of initial expectations, after which the return trip feels less bad in comparison, a condition was added where the initial expectations were manipulated. If, as indicated by participants in the previous studies, a feeling that the initial trip took much longer than expected contributes to the return trip effect, making participants expect an overly long initial trip should lessen or eliminate the return trip effect. Finally, order of estimates was manipulated to make sure that when the estimates were given could not account for the return trip effect.

One hundred thirty-nine participants (94 females, M age = 21 years) took part in a series of studies of which ours was part. The basic setup was that participants were seated behind a computer and were told that they would see a video of a student who traveled by bike from her house to that of a friend. The video was shot from the viewpoint of the person riding the bike (the rider could not be seen). The bike ride took exactly 7 min, during which a distance of 2.25 km was traveled. After this video had been seen, other studies followed for about 10 min. Next, the participants again watched a video of the student riding a bike, but now described as returning from her friend’s house to her home (with exactly the same time length). The main dependent variables were again how long participants felt the initial trip and the return trip took. Five conditions were created:

Basic return trip effect . After seeing the return trip, participants were asked to indicate how long they felt that the return trip had taken (on a sliding scale that could range between 1 and 20 min). After answering this question, they indicated how long they had felt that the initial trip had lasted, on the same scale.

Question order control . This condition was exactly the same as the basic return trip effect condition, except that the order of the estimates was varied. Participants first indicated how long the initial trip had felt and then how long the return trip had felt.

Question timing control . This procedure was the same as that of the basic return trip effect condition, but participants indicated how long the initial trip felt directly after viewing the initial trip. After they saw the return trip, they indicated how long they felt the return trip had taken.

Different return trip . The procedure was exactly the same as that of the basic return trip effect, but the video of the return trip showed a different (but equally long) route on the return trip.

Expectancy manipulation before initial trip . The procedure was exactly the same as that of the basic return trip effect, but before the participants saw the initial trip, they were told that they would first read what a previous participant had written about his experience after watching the video. They were presented with a handwritten statement, which was scanned in and presented on the screen. It first read the instruction to that other participant: “Please write down what your experience was (what you thought or felt) when you watched the video of the student riding her bike.” It was answered with: “phewwww, that video took a lot longer than I expected.”

We conducted a mixed-model Type III ANOVA with time estimates of the initial and return trips as within-subjects variables and the five conditions described above as the between-subjects variable. Across conditions, a clear return trip effect existed. Participants felt that the initial trip took a lot longer ( M = 9.12 min, SD = 3.54) than the return-trip did ( M = 7.35, SD = 2.59), F (1, 134) = 70.35, p < .001, η 2 p = .34, even though both took exactly 7 min. An interaction effect indicated that differences existed between conditions, F (4, 134) = 2.97, p = .022, η 2 p = .08 (see Table  1 for full results). In the three basic control conditions (where only the question order or timing was manipulated), a significant return trip effect existed. Note that an analysis of the difference between the estimates of the initial and the return trips showed that asking for a time estimate of the initial trip directly after that trip had been seen reduced the return trip effect, as compared with the basic return trip effect condition ( p = .061) and the question order control condition ( p = .042). The latter conditions did not differ ( p = .972). This demonstrates that the order in which questions about the time estimates of the initial or return trip are asked does not eliminate the return trip effect, although asking for a time estimate directly after the initial trip does seem to reduce it somewhat.

A conservative way of testing the return trip effect is to compare the time estimates of the participants who estimated the duration of the initial trip directly after seeing it (in the question timing control condition, M = 9.21 min, SD = 3.99) with those of the participants who made an estimate of the return trip directly after seeing the return trip (in the basic return trip effect condition, M = 7.14 min, SD = 2.21). This between-subjects analysis also strongly confirms the existence of the return trip effect, t (54) = 2.40, p = .020, d = 0.64. This shows that the return trip effect is not only a within-subjects phenomenon, and it rules out the possibility that the pattern exists because people might have a lay theory regarding a return trip that they wish to confirm.

Given that there was a return trip effect and question order did not appear to matter, we next examined the effect of familiarity with the return trip. One group of participants watched the rider travel back via a different (but equally long) route, while the remaining participants saw the rider return by the same initial route. As in the previous study, the return trip effect remained when participants returned by a different route: The different return trip group did not differ from the basic control ( p = .667), the question order control ( p = .554), or the question timing control ( p = .147) group. Being familiar with the return trip is not necessary for the return trip effect to occur, nor does it seem to influence the strength of the effect.

Recall that in the previous two studies, the more participants felt that the initial trip took longer than expected, the stronger they experienced the return trip effect. Therefore, in the expectancy manipulation condition, participants were led to believe that the initial trip would take a long time so that there would not be a violation of expectations. If the return trip effect is due to a violation of initial expectations for a short trip, lengthening participants’ expectations for the initial trip should lessen or eliminate the return trip effect. Indeed, in this condition, no return trip effect existed, since the estimates of how long the initial and return trips felt did not differ (see Table  1 ). Ironically, when a manipulation made participants expect a longer initial trip, they actually experienced the trip as taking less time, as compared with participants in the other conditions, as indicated by a planned contrast t (134) = 1.76, p = .08, d = 0.31. This is further support for the idea that one of the causes of the return trip effect is that people are generally disappointed in the initial trip, after which the return trip seems relatively short again.

These studies demonstrate that there is a return trip effect; a pretest shows that people regularly experience the return trip as being shorter than the initial trip, and the effect was found on a bus trip ( Study 1 ), a bicycle trip ( Study 2 ), and while a video of someone else traveling by bike was watched ( Study 3 ). The return trip effect is quite large: In Study 2 , the return trip was felt to be 17% shorter in duration than the initial trip; in Study 3 , it was felt to be 22% shorter (across the four conditions in which an effect was predicted).

The results indicate that the return trip effect is not due to an increase in familiarity, since the return trip effect also exists when people travel a different but equally long trip back. Instead, the return trip effect is likely due to a violation of expectations. Participants felt that the initial trip took longer than they had expected. In response, they likely lengthened their expectations for the return trip. In comparison with this longer expected duration, the return trip felt short. The greater the participants’ expectations were violated on the initial trip, the more they experienced the return trip effect (Studies 1 and 2). In Study 3 , where participants’ expectations for the duration of the initial trip were increased via a manipulation, the return trip effect disappeared.

It is possible that other causes exist for the return trip effect and that it is a multidetermined phenomenon. The main goal of the present research was to test whether a return trip effect exists and to test two possible explanations. It provides a starting point for subsequent research that examines the role of other aspects, such as motivation, valence of the trip and destination, and the effect of learning on the return trip effect—what strengthens it and what the boundary conditions are.

Finding that a violation of expectations (at least partly) causes the return trip effect does allow us to make new predictions related to the return trip effect. One of our personal observations on the return trip effect is that it does not seem to occur for routes traveled frequently, such as commuting to work. It is likely that for these routes, the expectations become more accurate with repeated feedback (Roy, Mitten, & Christenfeld, 2008 ), which attenuates the return trip effect.

More generally, the findings on the return trip effect could also help us predict people’s time estimates on other repeated tasks. For example, we predict that people who watch a movie for a second time are likely to perceive the second viewing as taking less time (especially if the first viewing seemed overly long). Indeed, one of the authors noted a similar effect when reading a story to his children the second time. These findings on the return trip effect can thus help us make new predictions on how people experience the duration of tasks unrelated to traveling as well.

How long the trip took had no influence on any of our measures, all β s < .15, p s > .2.

Eight participants were excluded from the analysis, since they got lost during the return trip. Three more were deleted because a multivariate outlier analysis indicated that their responses deviated strongly from the responses of the other participants.

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Acknowledgements

The authors thank Leanne Braber and Terri Seuntjens for their help in conducting the studies and Veolia and OAD for providing the opportunity to contact their travelers in Study 1 . Part of this research was made possible by a Rubicon grant (446-09-013) provided by the Netherlands Organization for Scientific Research (NWO).

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van de Ven, N., van Rijswijk, L. & Roy, M.M. The return trip effect: Why the return trip often seems to take less time. Psychon Bull Rev 18 , 827–832 (2011). https://doi.org/10.3758/s13423-011-0150-5

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Everyday Psych

The Return Trip Effect

The real voyage of discovery consists not in seeking new landscapes but in having new eyes. – Marcel Proust

The return to graduate school after winter break is always tougher than I expect. From being treated like a prince at home, I return to the stables where memories of grand feasts, shoulder rubs, and encouraged slothfulness are replaced with stale PB&J’s, knotted muscles, and an alarm clock that won’t shut the hell up.

However, in typical cosmic humor, there was a way to make the transition even worse: the expected 5.5-hour flight back to Ohio turned into a 16-hour one.

That is, why does the “return trip effect” actually happen?

To test this, the researchers first wanted to document that this was actually a real phenomenon people experienced. And to do so, they surveyed a bunch of people before they took a particular bus trip and after they took that same bus trip home.

As expected, people did indeed believe that the trip home felt much faster than the trip out.

So now you’re thinking: okay, Jake, so far you’ve spent 220 words to mildly entertain me with your meager inconveniences (you traveled thousands of miles, in the air , and didn’t die—and you want to complain?) but when are we going to get to the effect?

Well, to explain things, the researchers first tested one plausible hypothesis: because you’re more familiar with the surroundings on the return trip, maybe it simply feels faster than does the strange environment on the trip out.

However, when the researchers had participants bicycle back home either 1) along the path they had taken out there, i.e., the familiar one, or 2) along a different but equidistant path, there were no differences in estimating how long the return trip took.

In fact, this expectation phenomenon was found in both the previously described studies as well as a third, where participants were intentionally led to have expectations that the trip out would take longer or shorter than it actually did.

The researchers contend that when people believe the destination trip took longer than expected, they adjusted their expectations for the trip home, anticipating that it, too, would now take longer than expected. However, when they arrive sooner than their exaggerated expectation, the return trip suddenly feels much shorter.

So how could I have applied this to the unfortunate occurrence of my return flight?

I couldn’t. But hearing other people whine about how “incredibly awful” their flight delays were made me realize: Yeah, I don’t want to sound like those spoiled crybabies.

Especially when your main man psychophilosopher got bumped to first-class for the inconvenience.

Arrived last but seated first, jdt

Van de Ven, N., Van Rijswijk, L., & Roy, M. M. (2011). The return trip effect: Why the return trip often seems to take less time. Psychonomic Bulletin & Review, 18(5), 827-832.

Why travel feels longer on the way home

How can one leg of a trip seem so much different than the other psychologists and travel experts explain..

The vacation is over. You’ve soaked up sun in the Caribbean, and now you must embark on the slog back to reality. On the way there, you were jazzed and distracted: “Did I pack enough underwear ?” “Did we turn off the heater ?” The travel day went by in a scramble.

Going home is another story. The same three-hour journey seems to drag on between layovers, traffic and rest-stop food . The Biscoff has lost its novelty; the in-flight movies fall flat . As the minutes drip, you start to wonder, “How did we ever do this?” and, “Why, God, why?” You swear to never leave the house again.

How can one way feel so different than the other?

How optimism affects your perceived ETA

When they say, “It’s the journey, not the destination,” it’s the trip there we romanticize, not necessarily the trip home.

Yonason Goldson , an author and ethicist, says when we travel to a new place, we’re in a better head space. “There’s the expectation that something more exciting, something more interesting, something new, something fun is waiting for us,” he said. “That makes the trip part of the experience.”

By contrast, the trip home feels anticlimactic, Goldson says.

Neuropsychologist Sanam Hafeez , who practices in New York City, says it’s similar to the experience of your daily commute. On the way to work, you’re starting the day fresh with a lot on your plate. But when you’re exhausted at the end of the day, the sentiment is more, “I just want to get home already,” she said.

Hafeez experiences this after long weekends at her vacation home in the mountains. She’s done the drive enough that there’s no mystery as to how long it takes, just the pile of chores looming in her future.

“That’s been my experience, especially flying coast to coast,” Gary Small, chair of psychiatry at the Hackensack University Medical Center and author of “The Memory Bible.” “You’re really anticipating getting home, seeing the family. You’ve had enough.”

Small likens it to being back in school. Toward the end of the day, “we were always looking at that clock and waiting for it to hit 3:15, and those last minutes seem to take forever,” he said. “We wanted to get out and go home and play. The psychological component really colors it.”

Or maybe it’s the oncoming weight of the post-vacation blues . The Germans even have a word for it, says travel planner Sandra Weinacht: post-urlaubs-depression. Translation: the depression after the vacation. As the saying goes: Time flies when you’re having fun. Perhaps time crawls when you’re sad.

When the trip home doesn’t feel longer

In a highly unscientific poll I conducted on Instagram Stories , 126 respondents said travel feels longer on the way home, while 41 said it feels longer on the way there. A handful of participants from the latter camp sent messages emphatically defending their experience.

Sometimes the journey back feels shorter because it is shorter, thanks to the phenomenon of tailwinds — particularly when flying east — which can speed planes up. This could obviously work in reverse, making the trip there shorter.

But sometimes, it’s just a feeling. Hafeez and Small point to the “ return trip effect ,” which argues that the first leg of a trip can feel longer because of our tendency to inaccurately predict how long it will take. We may guess the way there will go by quicker than it does, and end up having a “ violation of expectation ” as a result.

“On the way back, because you’ve already experienced the longer trip, the return can actually feel shorter by comparison,” Hafeez said.

It could also be that, by the return trip, you’ve had some practice. The way there may feel mentally strenuous, but once you’ve gotten to know the route, Small says it can feel less challenging.

No novelty, no shortcuts

The return trip effect usually occurs when you’re traveling somewhere for the first time. So if you’re taking your usual summer vacation — the kind of trip you know so well you could get there with your eyes closed — the return can seem to stretch.

Small recommends introducing some novelty into the trip home to take the edge off. “That’s where the time distortion comes in,” he said. “Focusing on the anticipation of getting there rather than focusing on the moment and enjoying it.”

As a brain health and memory expert, Small often recommends people “train but don’t strain your brain.” He says that can be doing puzzles (if you’re not driving, obviously), engaging in conversations or taking different routes to challenge your mind during transit.

“When you don’t know the route and you’re discovering it, you’re kind of in the moment rather than anticipating the future,” Small said.

Hafeez recommends downloading plenty of podcasts or audiobooks , or arranging phone dates with people you’d like to catch up with if you’re going to be in the car for a long time.

Or you can tweak how you travel altogether. Susan Sherren, founder of the travel agency Couture Trips , encourages clients to plan trips with a “bell curve” itinerary. Ease into the vacation, crescendo into the exciting, action-packed days, then slow down before it’s over, so you’re not left feeling as frazzled.

You can also plan activities to look forward to when you get home to soften a crash landing back into your normal routine. Every time I pad my trip with a buffer day , I am eternally grateful.

More travel tips

Vacation planning: Start with a strategy to maximize days off by taking PTO around holidays. Experts recommend taking multiple short trips for peak happiness . Want to take an ambitious trip? Here are 12 destinations to try this year — without crowds.

Cheap flights: Follow our best advice for scoring low airfare , including setting flight price alerts and subscribing to deal newsletters. If you’re set on an expensive getaway, here’s a plan to save up without straining your credit limit.

Airport chaos: We’ve got advice for every scenario , from canceled flights to lost luggage . Stuck at the rental car counter? These tips can speed up the process. And following these 52 rules of flying should make the experience better for everyone.

Expert advice: Our By The Way Concierge solves readers’ dilemmas , including whether it’s okay to ditch a partner at security, or what happens if you get caught flying with weed . Submit your question here . Or you could look to the gurus: Lonely Planet and Rick Steves .

The return trip effect: why the return trip often seems to take less time

Affiliation.

• 1 Social Psychology & TIBER, Tilburg University, PO Box 90153, 5000LE, Tilburg, Netherlands. [email protected]
• PMID: 21861201
• PMCID: PMC3179583
• DOI: 10.3758/s13423-011-0150-5

Three studies confirm the existence of the return trip effect: The return trip often seems shorter than the initial trip, even though the distance traveled and the actual time spent traveling are identical. A pretest shows that people indeed experience a return trip effect regularly, and the effect was found on a bus trip (Study 1), a bicycle trip (Study 2), and when participants watched a video of someone else traveling (Study 3). The return trip effect also existed when another, equidistant route was taken on the return trip, showing that it is not familiarity with the route that causes this effect. Rather, it seems that a violation of expectations causes this effect.

Publication types

• Research Support, Non-U.S. Gov't
• Anticipation, Psychological
• Photic Stimulation
• Recognition, Psychology
• Time Factors
• Time Perception*
• Travel / psychology*
• Video Recording
• Visual Perception
• Young Adult

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'Return trip effect' isn't due to familiarity, says study

Getting to a destination usually feels longer than heading back from it. Known as "the return trip effect," the popular wisdom has been that it seems to take less time to go the same distance because a person is now familiar with the route having traveled it before.

But a new study has found that familiarity and predictability might not be the reasons a return trip feels shorter. It suggests a mismatch of expectations is more likely to be one of several possible causes.

"Everyone seemed to think that the return trip effect was caused by recognizing things along the way," says Niels van de Ven, the study's lead author. "However, I also experience it during airplane travel, where I don't recognize things. So I wanted to know why the effect existed."

To find out, his research team first tracked 69 participants on a day-long bus trip. Although each leg took the same amount of time, volunteers reported the initial trip took longer. The more participants believed the outbound route seemed slower than expected, the faster the return bus trip felt -- even though familiar landmarks were seen. 

The research appears in the journal Psychonomic Bulletin & Review.

A second study looked at a different form of transportation -- a bike trip. This time, 97 college freshman biked to a forest clearing using two equally distant routes. Two hours later, one-third returned by the same route while the rest headed back on a different route that was the same length.

Although all the routes took 35 minutes to ride, students estimated the outbound journey took 44 minutes and the return leg took 37 minutes. Students who rode two different routes tended to over-estimate the time each trip took compared to those who went out and back the same way. 

Whether by bus or bike, researchers were surprised to find that "people felt the return trip was about 22 percent shorter than the initial trip," says van de Ven, an assistant professor of social psychology at Tilburg University in the Netherlands.

He believes that what happens is people are typically too optimistic about the initial trip, which then takes disappointingly long. So when they return, they're now anticipating it will take a long time. But compared to this expectation, the return trip does not seem as bad.

Even so, there are some instances when the return trip effect doesn't apply. One is when a route becomes very familiar, such as a daily commute, because your expectations of the travel time become more accurate.

A second may be when you're going to a negative place, perhaps the dentist. You may arrive sooner than you'd like making the return home seem slower.

Also, you may not experience this effect on an out-and-back marathon course, when you're more exhausted on the return trip. And you wouldn't get the effect if you hiked the same distance up a mountain and then down it because the terrain changes.

Readers, what's your experience: Do you typically feel like a return trip takes a shorter amount of time? 

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The Return Trip Effect (RTE)

Many will have experienced the Return Trip Effect (RTE), whereby the outgoing journey to a destination (any mode of transport) very often 'seems' considerably longer than the return over exactly the same route.

As well as being widely-experienced, the effect is readily reproduced in lab-based experiments - and has been quite extensively investigated.

Despite the investigations, there is still no general agreement on why the effect occurs.

One theory was that it might depend on the familiarity with the route - but this was questioned by a 2011 study :

Three studies confirm the existence of the return trip effect: The return trip often seems shorter than the initial trip, even though the distance traveled and the actual time spent traveling are identical. A pretest shows that people indeed experience a return trip effect regularly, and the effect was found on a bus trip (Study 1), a bicycle trip (Study 2), and when participants watched a video of someone else traveling (Study 3). The return trip effect also existed when another, equidistant route was taken on the return trip, showing that it is not familiarity with the route that causes this effect. Rather, it seems that a violation of expectations causes this effect. See : The return trip effect: Why the return trip often seems to take less time Psychonomic Bulletin & Review volume 18, pages 827–832

A later, 2020 study found that :

[…] our anticipation account suggests that even when people travel to familiar destinations - such as a son going home from college to visit his parents - they may experience elongated time perception of the outbound trip, even though the destination is one of familiarity and certainty. We believe the present work offers avenues for future research. […] We hope this work also calls further attention to the importance of people’s perceptions of travel time in their social environment. Indeed, a rather large ocean of opportunity appears to exist to better understand the psychological substrates of time perception. See : Are We There Yet? An Anticipation Account of the Return Trip Effect [ paywalled ] Social Psychological and Personality Science, Volume 12, Issue 2.

Also see : Time Awareness plugin-autotooltip__plain plugin-autotooltip_big Time Awareness "Anticipating events that will happen in the future is among the most important functions the brain performs. Indeed, it has been increasingly stressed that learning and memory are prospective brain functions; that is, they are only adaptive to the extent that they help animals anticipate and prepare for the future (Dudai and Carruthers, 2005; Schacter and Addis, 2007). To anticipate when events will happen, the brain has evolved mechanisms to tell time across a wide range of te…

Researchers have figured out why return trips always seem to go by more quickly

If you've been one of the brave folks who took a long road trip or (gasp!) a plane flight this summer, you probably reacquainted yourself with the strange phenomenon known as the return-trip effect.

It's the feeling that the trip coming home was shorter than the outbound journey, although they actually took the same amount of time.

This feeling is so universal that it was even felt by Alan Bean in 1969 when he went to the moon as the lunar modular pilot on Apollo 12. "Returning from the moon seemed much shorter," Bean said.

The common reason given for the return-trip effect is that the journey home is less novel because we've already seen the remarkable sights on the way to the destination. Niels van de Ven, a psychologist at Tilburg University in the Netherlands believed the recognition of landmarks, "might help to increase the feeling of speed, of how fast you travel."

So van de Ven and his team set out to test that theory. One experiment they did was conducted on people riding bikes to a fair. He asked each person to ride the same way to the fair and then split up the bikers for the return trip.

The researchers asked one group to take the same route back that they took to the fair, and another to take a different route of the same distance.

If the familiarity explanation for the return-trip effect was correct, then the group that took a different route home would report that it felt like it took the same amount time as the journey to the fair.

But both groups reported that the journey home felt faster. So the researchers settled on a new hypothesis: the feeling of length is related to our expectations.

"Often we see that people are too optimistic when they start to travel," van de Ven said according to NPR. So when people begin their outbound trip it feels like it takes longer because of the excitement.

On the return home, the optimism is replaced by the pessimism that accompanies taking a long journey. "So you start the return journey, and you think, 'Wow, this is going to take a long time.'"

"It's really all about your expectations — what you think coming in," Michael Roy, a psychologist at Elizabethtown College and a co-author of the study, told NPR.

Psychologist Richard Block believes that it's all about focus and situation.

"When you have a destination you want to be there on time," Block said. "But when you go back home (return trip) it does not matter that much. Thus, when you are going there, your attention is more focused on the target and not distracted." In this case, being distracted makes the trip seem shorter.

In the report, the authors pin the phenomenon down to our personal expectations.

"Instead, the return trip effect is likely due to a violation of expectations," the report reads. "Participants felt that the initial trip took longer than they had expected. In response, they likely lengthened their expectations for the return trip. In comparison with this longer expected duration, the return trip felt short."

The study just goes to show how our attitudes can affect our very perception of reality, in this case, time. So the next question the researchers people should tackle is: does time fly when we're having fun? From this research, it seems the opposite may be true.

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Almost every long term relationship suffers from a rut eventually. That goes especially for married partners who become parents and have the added responsibility of raising kids. Maintaining a connection is hard enough in this busy, fast paced world. Top it off with making sure kids are awake, dressed, entertained, well fed, oh yeah, and alive …and you best believe all you have energy for at the end of the day is sitting on the couch barely making it through one episode on Netflix .

And yet, we know how important it is to maintain a connection with our spouses. Many of us just don’t know how to make that happen while juggling a million other things.

According to one mom, a “three-hour night” could be just the thing to tick off multiple boxes on the to-do list while rekindling romance at the same time. Talk about the ultimate marriage hack.

The three-hour night was something that Rachel Higgins and her husband began incorporating into their lives at the beginning of this year. And so far, “it's been so fun and such like a game changer for how our evenings go,” she says in a clip posted to TikTok.

Before using the three-hour night, the evening would look a bit like this: their daughter would go to bed, they would lounge on the couch, scroll through social media, then fall asleep. Sound familiar?

But with a three hour night, Higgins and her husband divvy up the time before bed into three section, each for a different focus.

In the first hour, starting around 7 p.m., is what Higgins calls “productive time,” during which the couple sees to any household chores that might need to be done.

“So start with like a quick cleanup of the kitchen or just like things that accumulated throughout the day, and then we try to do something that either ... has been being put off or cleaning the bathroom or like organizing the pantry or hall closet or something like, super random like sharpening the knives. Anything that's productive for the household,” she explains.

@rachelleehiggins if you’re stuck in a rut with your evenings try this! i saw someone do something similar to this a while ago but can’t remember who! #marriage   #1sttimeparents   #newyearsgoals   ♬ original sound - Rachel Higgins

Next, the second hour is geared towards re-establishing a physical or emotional connection in their marriage. The phones go away, and they focus only on enjoying one another.

“So, that could be things like showering together or ‘having fun’ together, playing a game together, or just like anything that's gonna get you guys talking and connecting or like debriefing from the day or just like talking about what you're doing and like the plans for tomorrow or like how works going or whatever. So, anything that's gonna connect and strengthen and build your marriage,” Higgins says.

Lastly, the final hour of the night is dedicated towards anything Higgins and her husband individually want to do, any sort of personal recharge activity.

Since this is a judgment free time, Higgins states that “If you just want to lay on the couch and scroll your phone and watch TikToks or whatever like watch YouTube videos,” it’s totally acceptable.

Higgins’ novel approach definitely interested viewers, who chimed in with their own questions. One major concern was how the heck this could be done every night. But even Higgins admits that she and her husband don’t succeed at having a three-hour night every night—they usually try for about 3-4 times a week. And honestly even once a week could still probably be beneficial in building intimacy.

Others wondered how to have a three-hour night when things randomly popped up in their schedule, like when kids won’t magically go to sleep promptly at 7pm. Higgins shares that in these cases, they tend to just shorten each phase. The point being: these can and probably should be customizable, even fun, rather than yet another rigid chore.

Plus, a three hour night (or whatever your version of a three-hour night may be) is a great way to remind yourself just how high of a priority your relationship has in your life…no matter what else is going on at the time. Odds are you'll probably find you do have more time for it than you previously thought when you set aside time for it.

This article originally appeared on 1.8.24

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It's time to rethink the term 'geriatric pregnancy' as more women wait to have children

Women are having children well past 40 but are considered "geriatric" after 35..

Rethinking the term 'geriatric pregnancy' as more women wait for kids

In more recent decades, women have started to delay having children or decide to not have them at all. Society has been taught that women must have children when they're in their 20s because that's when fertility is highest. Unfortunately it's true that fertility declines as women age, but pregnancy is still possible up until menopause.

Even if someone previously didn't want children, with technology they have the option to change their minds much later in life. Many women have taken to the idea of having more life and career experience before brining about children. But the language around pregnancy in women over 35 is still pretty offensive.

This now more common phenomenon of waiting until later in life to have children is medically called a geriatric pregnancy, though some doctors sugar coat it by calling it "advanced maternal age." Neither of these terms feels indicative of a warm feeling you're expected to experience while growing a child. BBC's The Global Story podcast blows through some pretty unfortunate misconceptions and truths about pregnancy after 35 in an interview with the Head of Reproductive Science and Sociology Group, UCL.

The two women co-hosting the podcast are both moms who waited to have children after the magic number. While having a baby after 35 is considered geriatric, some women are having babies into their 70s. Dr. Ssali says, "last week we successfully delivered this lady who was 70 years of age of twins, a boy and a girl. Previously we had treated her with IVF, again the same process, three years ago and she conceived and delivered a baby girl."

Of course choosing to have a baby in your 70s is well outside the normal age for childbearing, 35-50 isn't since many of these women are still capable of natural pregnancy without intervention . A woman's fertility decreases with age but it doesn't go down to zero until after menopause has fully set in. If it were impossible to conceive there wouldn't be a term called, " menopause baby ," which simply means someone became pregnant during their perimenopausal phase.

Professor Joyce Harper, the head of reproductive science and sociology explains, that while women's eggs lose fertility over the years, the uterus never does. This is why IVF using donated eggs for older hopeful parents can be successful. The trend of later in life babies isn't one to soon end as the age a woman births her first child increases by one year every decade.

"The average age [for first time moms] globally is 28," Stephanie Hegarty, BBC Population Correspondent says. "60 years ago the average age was 22 and every decade it's gone up globally by about a year."

Hegarty expands on the thought by adding people can continue to have babies as they get older. But when it comes to why people are choosing to have children later in life, economics plays a big part in whether people decide to have children or not. Raising a child is expensive and the cost of living has only gotten more exorbitant while wages have stayed largely the same. The experts on the podcast also said girls and women becoming more educated has pushed desires for motherhood to later years.

It's certainly something to consider when it comes to terminology. If the trend of increasing average age for women delivering their first child continues, then in another few decades, 35 will be the average age. Will we still be calling it geriatric pregnancy or advanced maternal age, then? Maybe a language change is in order before we reach that stage.

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Family posts a very chill note to neighbors explaining why their dog is on the roof

“we appreciate your concern but please do not knock on our door..".

Meet Huckleberry the dog.

If you were taking a stroll through a quiet neighborhood and happened to catch a glance of this majestic sight, you might bat an eye. You might do a double take. If you were (somewhat understandably) concerned about this surprising roof-dog's welfare, you might even approach the homeowners to tell them, "Uh, I'm not sure if you know...but there's a...dog...on your ROOF."

Well, the family inside is aware that there's often a dog on their roof . It's their pet Golden, Huckleberry, and he just sorta likes it up there.

To put passersby at ease and ebb the parade of concerned parties knocking on their door, Huckleberry's human put up a note explaining the whole weird scenario to those interested:

There’s a dog on the wooof!

"Huckleberry is living up to his name and learned how to jump onto our roof from the backyard. We never leave him in the backyard without someone being at home. He will not jump off unless you entice him with food or a ball!"" We appreciate your concern but please do not knock on our door... we know he's up there! But please feel free to take pictures of him and share with the world! #hucktheroofdog."

Of course, they ended it with a hashtag for photos shared on social media. Also, it seems a little strange that the owners mention that Huck is willing to jump 10 feet off a roof to chase food or a ball, but do nothing to suggest that people refrain from urging their dog to make that (seemingly dangerous) leap. Maybe Huck's got the whole process down to the point it's just not a concern.

This may seem like a pretty odd phenomenon, but not so odd that there isn't a whole corner of Reddit devoted to dogs who just seem to really, really enjoy roofs. It's called r/dogsonroofs , and boy does it ever deliver on that name.

This article originally appeared on 12.05.18

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Watching kids do lightning fast mental math is both mesmerizing and mind-blowing

Their finger twitching looks random, but wow is it impressive..

2003 UCMAS National Abacus & Mental Arithmetic Competition

In the age of calculators and smartphones , it's become less necessary to do math in your head than it used to be, but that doesn't mean mental math is useless. Knowing how to calculate in your head can be handy, and if you're lucky enough to learn mental abacus skills from a young age, it can be wicked fast as well.

Video of students demonstrating how quickly they can calculate numbers in their head are blowing people's minds, as the method is completely foreign for many of us. The use of a physical abacus isn't generally taught in the United States, other than perhaps a basic introduction to how it works. But precious few of us ever get to see how the ancient counter gets used for mental math.

The concept is simple and can be taught from a young age, but it takes a bit of time and practice to perfect. Watch what it looks like for basic addition and subtraction at lightning speed, though:

See on Instagram

If you don't know what they're doing, it looks like students are just randomly flicking their fingers and wrists. But they are actually envisioning the abacus while they move their fingers, as if they were actually using one.

There are various methods of finger calculations that make use of abacus concepts. Watch another method that uses both hands in action:

Even very young children can calculate large sums very quickly using these abacus-based mental math methods. Watch these little superstars add two-digit to four-digit numbers like it's nothing.

How do they do it?

Much of the skill here requires a solid understanding of how an abacus is used to calculate and lots of practice with the physical movements of calculating with it. That's not exactly simple to explain, as it take a couple of years of practice using an abacus—for these mental calculations, specifically the Japanese soroban abacus—to gain the skills needed to be able to calculate quickly. BBC Global shares how such practices are taught in Japan, not only for mental math but for overall cognitive memory:

Abacus mental math programs online recommend learning it between the ages of 5 to 13 . It is possible to learn at older ages, but it might take longer to master compared to younger students.

But if there's a finger method you want to try for addition and subtraction up to 99, one that's simple and quick to learn is called chisanbop, in which ones are counted on one hand and 10s are counted on the other. Here's an explainer video that shows how it works:

Most of us carry calculators around in our pockets with us at all time, so such practices may feel like a waste of time. But learning new skills that tax our brain is like a workout for our mind, so it's not a bad idea to give things like this a spin. Even if we don't learn to calculate large numbers in the blink of an eye, we can at least exercise our mental muscles to keep our brains healthier. And who knows, maybe we'll get a party trick or two out of it as well.

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Kristen Wiig plays a cult leader pilates coach in an epic 'SNL' return

Kristen wiig made an epic return to “saturday night live” this week.

A creepy slowed down version of Megan Thee Stallion's "Body" was a fabulous touch.

Kristen Wiig made an epic return to “ Saturday Night Live ” this week, and along with bringing back her iconic “ Aunt Linda ” character, she might have created a whole new fan favorite .

In a horror trailer reminiscent of an A24 film, Chloe Fineman and Molly Kearney work up the courage to take their first pilates class. They enter an eerily dark purple room where Wiig, playing a cult-leader Pilates instructor with a fondness for weird pet names, gives them the scariest workout of their life.

Now, look, pilates is a great form of exercise , with proven benefits for flexibility, core strength and posture. But when it comes to most pilates studios, there’s a certain…vibe. In a word, it’s intense . Anyone who’s been to a class can probably say they have a whole new relationship to discomfort.

And this sketch, along with Wiig’s performance, totally nailed all the typical pilates experience—from the intimidating reformer machines that look like they’re”designed for torture… but somehow, also sex,” to the mind boggling instructions during class (“take those ankle straps around your waist and your knee straps around your head!”) to the unbearable consequence of forgetting your special sticky socks. May god help you.

In fact, it got the seal of approval from bonafide Pilates regulars.

“As a person who has been doing pilates for over 5 years, this is 100% accurate lmao,” one viewer on Youtube wrote.

Another added, "I've done Pilates classes, and this made me laugh so hard because it's all true!"

Even a staff member for a pilates studio chimed in, saying “I work the front desk at a Pilates studio and this is perfectly accurate. I laughed so hard!”

Watch “a chilling new look at girl horror” below:

And don't forget: embrace the shake!!!

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Productivity expert shares the simple, 5-second trick that'll help you stop procrastinating

You have to beat your mind to the punch..

A man in a red shirt has an epiphany and Mel Robbins delivers a TED Talk.

It’s a wonder that humans can get anything done because we are hard-wired to procrastinate. Whenever we consider performing a task that may be boring, unpleasant, or stressful, the brain automatically sends a signal that says why not do it “later” or “tomorrow”?

Humans are natural-born procrastinators because our old brain wants to protect us from potential danger or discomfort. So, when faced with an uncomfortable situation, our brain springs into action and suggests we do it later.

While some people are able to override this reaction, many cannot and researchers believe that around 20% are chronic procrastinators.

As we all know, this knee-jerk reaction can cause all sorts of troubles. It can make it a lot harder to be a good employee, take care of domestic responsibilities, or ensure our school work is done on time. According to Psychological Science , chronic procrastinators have higher levels of anxiety and often have inadequate retirement savings.

It makes sense. When we put off taking care of the things we need to handle, they have a way of creeping up on us and creating a lot of anxiety.

The good news is that podcast host, author, motivational speaker and former lawyer Mel Robbins has a solution that can help many people bypass the procrastination impulse and get things done. She calls it the 5-Second Rule.

The technique just takes 3 easy steps:

• Recognize the moment that your mind begins to make excuses and tell you that whatever you need to do—whether it’s the dishes, your homework, or having a meaningful conversation—can be put off ‘til later.
• Start counting down in your head or out loud, “5-4-3-2-1.”
• Begin the task once you hit the number 1.

Why does it work? Counting down transitions your brain's function from the primitive, procrastinating midbrain to the prefrontal cortex, which is associated with decision-making. Also, by counting, your brain focuses on the numbers instead of making excuses, so nothing prevents you from starting the task.

According to Robbins, overcoming procrastination and taking care of business isn’t just about about being motivated.

“You think what you're missing is motivation, but that's not true,” says Robbins. "To change, to start a business, to be a better parent, a better companion, and to do all the things you want to achieve in life—you will necessarily have to go through complicated, scary and uncertain things. You’re never going to ‘feel it,’ but you can do it.”

She believes that techniques such as the 5-Second Rule allow us to regain control over our minds and bodies so we can live the lives we are truly meant to enjoy. According to Robbins, asserting control over our thoughts means “regaining confidence in yourself; fighting your fears; stopping stressing; living happier, and finally having the courage to share and defend your ideas.”

So next time you are about to start a new project but your brain tells you to first pick up your phone and scroll through Instagram, simply start counting down from 5. The desire will pass and you’ll have taken the first step toward achieving your goals and getting free from your old brain.

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What will Earth look like if all its land ice melts? Here's your answer.

Younger generations are torn over inheriting boomer heirlooms. here are 4 helpful tips., rescue dog owner brought to tears after giving her ‘super mutt’ a dna test, bill gates explains the ‘safest’ age to give a kid a cellphone, security cam captures assistant principal and student's joyful mutual birthday celebration, a story about two pairs of boots illustrates how rich people get richer in ways poor people can't.

25 Questions (and Answers!) About the Great North American Eclipse

The McDonald Observatory’s guide to one of nature’s most beautiful and astounding events: What you might see, how to view it safely, how astronomers will study it, how animals might react, and some of the mythology and superstitions about the Sun’s great disappearing act.

1. What’s happening?

The Moon will cross directly between Earth and the Sun, temporarily blocking the Sun from view along a narrow path across Mexico, the United States, and Canada. Viewers across the rest of the United States will see a partial eclipse, with the Moon covering only part of the Sun’s disk.

2. When will it happen?

The eclipse takes place on April 8. It will get underway at 10:42 a.m. CDT, when the Moon’s shadow first touches Earth’s surface, creating a partial eclipse. The Big Show—totality—begins at about 11:39 a.m., over the south-central Pacific Ocean. The shadow will first touch North America an hour and a half later, on the Pacific coast of Mexico. Moving at more than 1,600 miles (2,575 km) per hour, the path of totality will enter the United States at Eagle Pass, Texas, at 1:27 p.m. CDT. The lunar shadow will exit the United States and enter the Canadian province of New Brunswick near Houlton, Maine, at 2:35 p.m. (3:35 p.m. EDT).

3. How long will totality last?

The exact timing depends on your location. The maximum length is 4 minutes, 27 seconds near Torreon, Mexico. In the United States, several towns in southwestern Texas will see 4 minutes, 24 seconds of totality. The closer a location is to the centerline of the path of totality, the longer the eclipse will last.

4. What will it look like?

Eclipse veterans say there’s nothing quite like a total solar eclipse. In the last moments before the Sun disappears behind the Moon, bits of sunlight filter through the lunar mountains and canyons, forming bright points of light known as Baily’s beads. The last of the beads provides a brief blaze known as a diamond ring effect. When it fades away, the sky turns dark and the corona comes into view— million-degree plasma expelled from the Sun’s surface. It forms silvery filaments that radiate away from the Sun. Solar prominences, which are fountains of gas from the surface, form smaller, redder streamers on the rim of the Sun’s disk.

5. What safety precautions do I need to take?

It’s perfectly safe to look at the total phase of the eclipse with your eyes alone. In fact, experts say it’s the best way to enjoy the spectacle. The corona, which surrounds the intervening Moon with silvery tendrils of light, is only about as bright as a full Moon.

During the partial phases of the eclipse, however, including the final moments before and first moments after totality, your eyes need protection from the Sun’s blinding light. Even a 99-percent-eclipsed Sun is thousands of times brighter than a full Moon, so even a tiny sliver of direct sunlight can be dangerous!

To stay safe, use commercially available eclipse viewers, which can look like eyeglasses or can be embedded in a flat sheet that you hold in front of your face. Make sure your viewer meets the proper safety standards, and inspect it before you use it to make sure there are no scratches to let in unfiltered sunlight.

You also can view the eclipse through a piece of welder’s glass (No. 14 or darker), or stand under a leafy tree and look at the ground; the gaps between leaves act as lenses, projecting a view of the eclipse on the ground. With an especially leafy tree you can see hundreds of images of the eclipse at once. (You can also use a colander or similar piece of gear to create the same effect.)

One final mode of eclipse watching is with a pinhole camera. You can make one by poking a small hole in an index card, file folder, or piece of stiff cardboard. Let the Sun shine through the hole onto the ground or a piece of paper, but don’t look at the Sun through the hole! The hole projects an image of the eclipsed Sun, allowing you to follow the entire sequence, from the moment of first contact through the Moon’s disappearance hours later.

6. Where can I see the eclipse?

In the United States, the path of totality will extend from Eagle Pass, Texas, to Houlton, Maine. It will cross 15 states: Texas, Oklahoma, Arkansas, Missouri, Illinois, Indiana, Kentucky, Ohio, Pennsylvania, New York, Vermont, New Hampshire, Maine, Tennessee, and Michigan (although it barely nicks the last two).

In Texas, the eclipse will darken the sky over Austin, Waco, and Dallas—the most populous city in the path, where totality (the period when the Sun is totally eclipsed) will last 3 minutes, 51 seconds.

Other large cities along the path include Little Rock; Indianapolis; Dayton, Toledo, and Cleveland, Ohio; Erie, Pennsylvania; Buffalo and Rochester, New York; and Burlington, Vermont.

Outside the path of totality, American skywatchers will see a partial eclipse, in which the Sun covers only part of the Sun’s disk. The sky will grow dusky and the air will get cooler, but the partially eclipsed Sun is still too bright to look at without proper eye protection. The closer to the path of totality, the greater the extent of the eclipse. From Memphis and Nashville, for example, the Moon will cover more than 95 percent of the Sun’s disk. From Denver and Phoenix, it’s about 65 percent. And for the unlucky skywatchers in Seattle, far to the northwest of the eclipse centerline, it’s a meager 20 percent.

The total eclipse path also crosses Mexico, from the Pacific coast, at Mazatlán, to the Texas border. It also crosses a small portion of Canada, barely including Hamilton, Ontario. Eclipse Details for Locations Around the United States • aa.usno.navy.mil/data/Eclipse2024 • eclipse.aas.org • GreatAmericanEclipse.com

7. What causes solar eclipses?

These awe-inspiring spectacles are the result of a pleasant celestial coincidence: The Sun and Moon appear almost exactly the same size in Earth’s sky. The Sun is actually about 400 times wider than the Moon but it’s also about 400 times farther, so when the new Moon passes directly between Earth and the Sun—an alignment known as syzygy—it can cover the Sun’s disk, blocking it from view.

8. Why don’t we see an eclipse at every new Moon?

The Moon’s orbit around Earth is tilted a bit with respect to the Sun’s path across the sky, known as the ecliptic. Because of that angle, the Moon passes north or south of the Sun most months, so there’s no eclipse. When the geometry is just right, however, the Moon casts its shadow on Earth’s surface, creating a solar eclipse. Not all eclipses are total. The Moon’s distance from Earth varies a bit, as does Earth’s distance from the Sun. If the Moon passes directly between Earth and the Sun when the Moon is at its farthest, we see an annular eclipse, in which a ring of sunlight encircles the Moon. Regardless of the distance, if the SunMoon-Earth alignment is off by a small amount, the Moon can cover only a portion of the Sun’s disk, creating a partial eclipse.

9. How often do solar eclipses happen?

Earth sees as least two solar eclipses per year, and, rarely, as many as five. Only three eclipses per two years are total. In addition, total eclipses are visible only along narrow paths. According to Belgian astronomer Jean Meuss, who specializes in calculating such things, any given place on Earth will see a total solar eclipse, on average, once every 375 years. That number is averaged over many centuries, so the exact gap varies. It might be centuries between succeeding eclipses, or it might be only a few years. A small region of Illinois, Missouri, and Kentucky, close to the southeast of St. Louis, for example, saw the total eclipse of 2017 and will experience this year’s eclipse as well. Overall, though, you don’t want to wait for a total eclipse to come to you. If you have a chance to travel to an eclipse path, take it!

10. What is the limit for the length of totality?

Astronomers have calculated the length of totality for eclipses thousands of years into the future. Their calculations show that the greatest extent of totality will come during the eclipse of July 16, 2186, at 7 minutes, 29 seconds, in the Atlantic Ocean, near the coast of South America. The eclipse will occur when the Moon is near its closest point to Earth, so it appears largest in the sky, and Earth is near its farthest point from the Sun, so the Sun appears smaller than average. That eclipse, by the way, belongs to the same Saros cycle as this year’s.

11. When will the next total eclipse be seen from the United States?

The next total eclipse visible from anywhere in the United States will take place on March 30, 2033, across Alaska. On August 22, 2044, a total eclipse will be visible across parts of Montana, North Dakota, and South Dakota. The next eclipse to cross the entire country will take place on August 12, 2045, streaking from northern California to southern Florida. Here are the other total solar eclipses visible from the contiguous U.S. this century:

March 30, 2052 Florida, Georgia, tip of South Carolina May 11, 2078 From Louisiana to North Carolina May 1, 2079 From Philadelphia up the Atlantic coast to Maine September 14, 2099 From North Dakota to the Virginia-North Carolina border

12. What is the origin of the word ‘eclipse?’

The word first appeared in English writings in the late 13th century. It traces its roots, however, to the Greek words “ecleipsis” or “ekleipein.” According to various sources, the meaning was “to leave out, fail to appear,” “a failing, forsaking,” or “abandon, cease, die.”

13. Do solar eclipses follow any kind of pattern?

The Moon goes through several cycles. The best known is its 29.5-day cycle of phases, from new through full and back again. Other cycles include its distance from Earth (which varies by about 30,000 miles (50,000 km) over 27.5 days) and its relationship to the Sun’s path across the sky, known as the ecliptic (27.2 days), among others. These three cycles overlap every 6,585.3 days, which is 18 years, 11 days, and 8 hours.

This cycle of cycles is known as a Saros (a word created by Babylonians). The circumstances for each succeeding eclipse in a Saros are similar—the Moon is about the same distance from Earth, for example, and they occur at the same time of year. Each eclipse occurs one-third of the way around Earth from the previous one, however; the next eclipse in this Saros, for example, will be visible from parts of the Pacific Ocean.

Each Saros begins with a partial eclipse. A portion of the Moon just nips the northern edge of the Sun, for example, blocking only a fraction of the Sun’s light. With each succeeding eclipse in the cycle, the Moon covers a larger fraction of the solar disk, eventually creating dozens of total eclipses. The Moon then slides out of alignment again, this time in the opposite direction, creating more partial eclipses. The series ends with a grazing partial eclipse on the opposite hemisphere (the southern tip, for example).

Several Saros cycles churn along simultaneously (40 are active now), so Earth doesn’t have to wait 18 years between eclipses. They can occur at intervals of one, five, six, or seven months.

The April 8 eclipse is the 30th of Saros 139, a series of 71 events that began with a partial eclipse, in the far north, and will end with another partial eclipse, this time in the far southern hemisphere. The next eclipse in this Saros, also total, will take place on April 20, 2042.

First eclipse May 17, 1501

First total eclipse December 21, 1843

Final total eclipse March 26, 2601

Longest total eclipse July 16, 2186,  7 minutes, 29 seconds

Final partial eclipse July 3, 2763

All eclipses 71 (43 total, 16 partial, 12 hybrid)

Source: NASA Catalog of Solar Eclipses: eclipse.gsfc.nasa.gov/SEsaros/SEsaros139.html

14. What about eclipse seasons?

Eclipses occur in “seasons,” with two or three eclipses (lunar and solar) in a period of about five weeks. Individual eclipses are separated by two weeks: a lunar eclipse at full Moon, a solar eclipse at new Moon (the sequence can occur in either order). If the first eclipse in a season occurs during the first few days of the window, then the season will have three eclipses. When one eclipse in the season is poor, the other usually is much better.

That’s certainly the case with the season that includes the April 8 eclipse. It begins with a penumbral lunar eclipse on the night of March 24, in which the Moon will pass through Earth’s outer shadow. The eclipse will cover the Americas, although the shadow is so faint that most skywatchers won’t notice it.

This article was previously published in the March/April 2024 issue of StarDate  magazine, a publication of The University of Texas at Austin’s McDonald Observatory. Catch StarDate’s daily radio program on more than 300 stations nationwide or subscribe online at  stardate.org .

15. How can astronomers forecast eclipses so accurately?

They’ve been recording eclipses and the motions of the Moon for millennia. And over the past half century they’ve been bouncing laser beams off of special reflectors carried to the Moon by Apollo astronauts and Soviet rovers. Those observations reveal the Moon’s position to within a fraction of an inch. Using a combination of the Earth-Moon distance, the Moon’s precise shape, Earth’s rotation and its distance from the Sun, and other factors, astronomers can predict the timing of an eclipse to within a fraction of a second many centuries into the future.

Edmond Halley made the first confirmed solar eclipse prediction, using the laws of gravity devised only a few decades earlier by Isaac Newton. Halley forecast that an eclipse would cross England on May 3, 1715. He missed the timing by just four minutes and the path by 20 miles, so the eclipse is known as Halley’s Eclipse.

16. What are the types of solar eclipses?

Total : the Moon completely covers the Sun.

Annular : the Moon is too far away to completely cover the Sun, leaving a bright ring of sunlight around it.

Partial : the Moon covers only part of the Sun’s disk.

Hybrid : an eclipse that is annular at its beginning and end, but total at its peak.

17. What are Baily’s beads?

During the minute or two before or after totality, bits of the Sun shine through canyons and other features on the limb of the Moon, producing “beads” of sunlight. They were first recorded and explained by Edmond Halley, in 1715. During a presentation to the Royal Academy of Sciences more than a century later, however, astronomer Frances Baily first described them as “a string of beads,” so they’ve been known as Baily’s beads ever since. Please note that Baily’s beads are too bright to look at without eye protection!

18. Will Earth always see total solar eclipses?

No, it will not. The Moon is moving away from Earth at about 1.5 inches (3.8 cm) per year. Based on that rate of recession, in about 600 million years the Moon would have moved so far from Earth that it would no longer appear large enough to cover the Sun. The speed at which the Moon separates from Earth changes over the eons, however, so scientists aren’t sure just when Earth will see its final total solar eclipse.

19. How will the eclipse affect solar power?

If your solar-powered house is in or near the path of totality, the lights truly will go out, as they do at night. For large power grids, the eclipse will temporarily reduce the total amount of electricity contributed by solar generation. During the October 14, 2023, annular eclipse, available solar power plummeted in California and Texas. At the same time, demand increased as individual Sun-powered homes and other buildings began drawing electricity from the power grid. Both networks were able to compensate with stations powered by natural gas and other sources.

The power drop during this year’s eclipse could be more dramatic because there will be less sunlight at the peak of the eclipse.

20. What are some of the myths and superstitions associated with solar eclipses?

Most ancient cultures created stories to explain the Sun’s mysterious and terrifying disappearances.

In China and elsewhere, it was thought the Sun was being devoured by a dragon. Other cultures blamed a hungry frog (Vietnam), a giant wolf loosed by the god Loki (Scandinavia), or the severed head of a monster (India). Still others saw an eclipse as a quarrel (or a reunion) between Sun and Moon. Some peoples shot flaming arrows into the sky to scare away the monster or to rekindle the solar fire. One especially intriguing story, from Transylvania, said that an eclipse occurred when the Sun covered her face in disgust at bad human behavior.

Eclipses have been seen as omens of evil deeds to come. In August 1133, King Henry I left England for Normandy one day before a lengthy solar eclipse, bringing prophesies of doom. The country later was plunged into civil war, and Henry died before he could return home, strengthening the impression that solar eclipses were bad mojo.

Ancient superstitions claimed that eclipses could cause plague and other maladies. Modern superstitions say that food prepared during an eclipse is poison and that an eclipse will damage the babies of pregnant women who look at it. None of that is true, of course. There’s nothing at all to fear from this beautiful natural event.

21. How do animals react to solar eclipses?

Scientists haven’t studied the topic very thoroughly, but they do have some general conclusions. Many daytime animals start their evening rituals, while many nighttime animals wake up when the eclipse is over, perhaps cursing their alarm clocks for letting them sleep so late!

During the 2017 total eclipse, scientists observed 17 species at Riverbanks Zoo in Columbia, South Carolina. About three-quarters of the species showed some response as the sky darkened. Some animals acted nervous, while others simply headed for bed. A species of gibbon had the most unusual reaction, moving excitedly and chattering in ways the zookeepers hadn’t seen before.

Other studies have reported that bats and owls sometimes come out during totality, hippos move toward their nighttime feeding grounds, and spiders tear down their webs, only to rebuild them when the Sun returns. Bees have been seen to return to their hives during totality and not budge until the next day, crickets begin their evening chorus, and, unfortunately, mosquitoes emerge, ready to dine on unsuspecting eclipse watchers.

A NASA project, Eclipse Soundscapes, is using volunteers around the country to learn more about how animals react to the changes. The project collected audio recordings and observations by participants during the annular eclipse last year, and will repeat the observations this year. Volunteers can sign up at eclipsesoundscapes.org

22. How will scientists study this year’s eclipse?

Astronomers don’t pay quite as much professional attention to solar eclipses as they did in decades and centuries past. However, they still schedule special observations to add to their knowledge of the Sun and especially the inner edge of the corona.

Sun-watching satellites create artificial eclipses by placing a small disk across the face of the Sun, blocking the Sun’s disk and revealing the corona, solar prominences, and big explosions of charged particles known as coronal mass ejections.

Because of the way light travels around the edges of an eclipsing disk, however, it’s difficult to observe the region just above the Sun’s visible surface, which is where much of the action takes place. The corona is heated to millions of degrees there, and the constant flow of particles known as the solar wind is accelerated to a million miles per hour or faster, so solar astronomers really want to see that region in detail. The eclipsing Moon doesn’t create the same effects around the limb of the Sun, so a solar eclipse still provides the best way to look close to the Sun’s surface.

For this year’s eclipse, some scientists will repeat a series of experiments they conducted in 2017 using a pair of highaltitude WB-57 aircraft to “tag team” through the lunar shadow, providing several extra minutes of observations.

Other scientists will use the eclipse to study Earth’s ionosphere, an electrically charged layer of the atmosphere that “bends” radio waves, allowing them to travel thousands of miles around the planet. Sunlight rips apart atoms and molecules during the day, intensifying the charge. At night, the atoms and molecules recombine, reducing the charge.

Physicists want to understand how the ionosphere reacts to the temporary loss of sunlight during an eclipse. They will do so with the help of thousands of volunteer ham radio operators, who will exchange messages with others around the planet. During last October’s annular eclipse, when the Moon covered most but not all of the Sun, the experiment showed a large and immediate change in the ionosphere as the sunlight dimmed.

NASA also will launch three small “sounding” rockets, which loft instruments into space for a few minutes, to probe the ionosphere shortly before, during, and shortly after the eclipse.

Another project will use radar to study changes in the interactions between the solar wind and Earth’s atmosphere, while yet another will use a radio telescope to map sunspots and surrounding regions as the Moon passes across them.

One project will piece together images of the eclipse snapped through more than 40 identical telescopes spaced along the path of totality to create a one-hour movie of the eclipse. The telescopes will be equipped with instruments that see the three-dimensional structure of the corona, allowing solar scientists to plot how the corona changes.

23. What have astronomers learned from eclipses?

Solar eclipses have been powerful tools for studying the Sun, the layout of the solar system, and the physics of the universe.

Until the Space Age, astronomers could see the Sun’s corona only during eclipses, so they traveled around the world to catch these brief glimpses of it.

Eclipses also offered a chance to refine the scale of the solar system. Watching an eclipse from different spots on Earth and comparing the angles of the Moon and Sun helped reveal the relative sizes and distances of both bodies, which were important steps in understanding their true distances.

During an eclipse in 1868, two astronomers discovered a new element in the corona. It was named helium, after Helios, a Greek name for the Sun. The element wasn’t discovered on Earth until a quarter of a century later.

An eclipse in 1919 helped confirm General Relativity, which was Albert Einstein’s theory of gravity. The theory predicted that the gravity of a massive body should deflect the path of light rays flying near its surface. During the eclipse, astronomers found that the positions of background stars that appeared near the Sun were shifted by a tiny amount, which was in perfect agreement with Einstein’s equations.

Today, astronomers are using records of eclipses dating back thousands of years to measure changes in Earth’s rotation rate and the distance to the Moon.

24. How did astronomers study eclipses in the past?

With great effort! From the time they could accurately predict when and where solar eclipses would be visible, they organized expeditions that took them to every continent except Antarctica, on trips that lasted months and that sometimes were spoiled by clouds or problems both technical and human.

During the American Revolution, for example, a group of Harvard scientists led by Samuel Williams received safe passage from the British army to view an eclipse from Penobscot Bay, Maine, on October 21, 1780. Williams slightly miscalculated the eclipse path, though, so the group missed totality by a few miles. (The expedition did make some useful observations, however.)

In 1860, an expedition headed by Simon Newcomb, one of America’s top astronomers, journeyed up the Saskatchewan River, hundreds of miles from the nearest city, braving rapids, mosquitoes, and bad weather. After five grueling weeks, they had to stop short of their planned viewing site, although at a location still inside the eclipse path. Clouds covered the Sun until almost the end of totality, however, so the expedition came up empty.

King Mongkut of Siam invited a French expedition and hundreds of other dignitaries to view an eclipse from present-day Thailand in 1868. He built an observatory and a large compound to house his guests at a site Mongkut himself had selected as the best viewing spot. The eclipse came off perfectly, but many visitors contracted malaria. So did Mongkut, who died a few weeks later.

An expedition in 1914, to Russia, was plagued by both clouds and the start of World War I. The team abandoned its instruments at a Russian observatory and escaped through Scandinavia.

The eclipse of July 29, 1878, offered fewer impediments. In fact, it was a scientific and social extravaganza. The eclipse path stretched from Montana Territory to Texas. Teams of astronomers from the United States and Europe spread out along the path. Thomas Edison stationed his group in Wyoming, where he used a tasimeter, a device of his own creation, to try to measure the temperature of the corona. Samuel Pierpoint Langley, a future secretary of the Smithsonian, was atop Pikes Peak in Colorado. Maria Mitchell, perhaps America’s leading female scientist, decamped to Denver. And Asaph Hall, who had discovered the moons of Mars just the year before, journeyed to the flatlands of eastern Colorado.

Thousands of average Americans joined the festivities, paying outrageous prices for some of the best viewing spots. Some things, it seems, never change.

25. What about lunar eclipses?

While solar eclipses happen during new Moon, lunar eclipses occur when the Moon is full, so it aligns opposite the Sun in our sky. The Moon passes through Earth’s shadow. In a total eclipse, the entire lunar disk turns orange or red. In a partial eclipse, Earth’s inner shadow covers only a portion of the Moon. And during a penumbral eclipse, the Moon passes through the outer portion of Earth’s shadow, darkening the Moon so little that most people don’t even notice it.

Lunar eclipses happen as often as solar eclipses—at least twice per year. This is a poor year for lunar eclipses, however. There is a penumbral eclipse on the night of March 24, with the Moon slipping through Earth’s faint outer shadow, and a partial eclipse on the night of September 17, in which the Moon barely dips into the darker inner shadow. Both eclipses will be visible from most of the United States.

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The Return Trip Is Felt Shorter Only Postdictively: A Psychophysiological Study of the Return Trip Effect

Ryosuke ozawa.

1 Laboratory of Neurophysiology, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan

Keisuke Fujii

2 Japan Society for the Promotion of Science, Tokyo, Japan

Motoki Kouzaki

Conceived and designed the experiments: RO KF MK. Performed the experiments: RO. Analyzed the data: RO KF MK. Contributed reagents/materials/analysis tools: RO KF MK. Wrote the paper: RO KF MK.

Associated Data

All relevant data are within the paper.

The return trip often seems shorter than the outward trip even when the distance and actual time are identical. To date, studies on the return trip effect have failed to confirm its existence in a situation that is ecologically valid in terms of environment and duration. In addition, physiological influences as part of fundamental timing mechanisms in daily activities have not been investigated in the time perception literature. The present study compared round-trip and non-round-trip conditions in an ecological situation. Time estimation in real time and postdictive estimation were used to clarify the situations where the return trip effect occurs. Autonomic nervous system activity was evaluated from the electrocardiogram using the Lorenz plot to demonstrate the relationship between time perception and physiological indices. The results suggest that the return trip effect is caused only postdictively. Electrocardiographic analysis revealed that the two experimental conditions induced different responses in the autonomic nervous system, particularly in sympathetic nervous function, and that parasympathetic function correlated with postdictive timing. To account for the main findings, the discrepancy between the two time estimates is discussed in the light of timing strategies, i.e., prospective and retrospective timing, which reflect different emphasis on attention and memory processes. Also each timing method, i.e., the verbal estimation, production or comparative judgment, has different characteristics such as the quantification of duration in time units or knowledge of the target duration, which may be responsible for the discrepancy. The relationship between postdictive time estimation and the parasympathetic nervous system is also discussed.

Introduction

Our perception of time is a guiding force in our behaviors because it is an essential component of cognition and motor performance, representing one of the basic mechanisms of cerebral function [ 1 ]. To deal with time, multiple systems over more than ten orders of magnitude have been developed because we process and use temporal information across a wide range of intervals [ 2 ]. Time perception researchers often separate time into millisecond timing, interval timing including the range of seconds-to-minutes-to-hours, and circadian timing [ 2 ]. In this paper we call timing in the range of minutes-to-hours “real-life” timing in order to highlight its relevance to our daily life. Interval timing is less accurate than other timing ranges [ 2 , 3 ]. Because of this inaccuracy, we experience many odd phenomena related to time perception. For example, when we go from a station to a destination, and return to the same station, the return trip often seems shorter than the outward trip, though the distance traveled and the actual duration of the trips are almost identical. This phenomenon is called the “return trip effect” [ 4 ].

Zakay [ 5 ] discussed this effect from the viewpoint of time relevance, which indicates how important it is in a specific situation to be aware of the passage of time. The higher the time relevance, the more attentional resources will be allocated to time and therefore the longer the estimate of duration. When we have to go somewhere at a certain time for an important event, time relevance is high. On the contrary, when returning to the starting point, time is not so important and time relevance is low. However, two studies directly examining the return trip effect provide other potential explanations. These studies did not include a purpose for the outward trip; therefore, time relevance seemed to be equal between outward and return trips. Ven et al. [ 4 ] confirmed that the return trip effect is frequently experienced in daily life. They also reported that it is not due to an increase in familiarity with a route, but is probably due to a violation of expectations for the durations of trips: the more the participants’ expectations were violated on the initial trip, the more they experienced the return trip effect. Seno et al. [ 6 ] conducted a virtual travel experiment with verbal instructions and examined two factors: one perceptual (optic flow inducing self-motion perception or random dot control condition) and one cognitive (with or without a round trip story). Their results indicate that the return trip effect is induced only when self-motion perception is accompanied by the round-trip story, in other words, by combined perceptual and cognitive factors.

The foregoing studies provide important suggestions about the return trip effect, but there are also some problems. One is that a comparison between the round-trip condition and non-round-trip condition in an environment close to daily experience is needed. Ven et al. [ 4 ] used actual trips, or virtual trips by movies, but they compared only round-trip conditions, without a control condition. Seno et al. [ 6 ] examined the round-trip and non-round-trip conditions, but their experimental environment seems to be far from actuality, and the duration of the task (40 s) was much shorter than real-life trips. Recently, the need for ecologically valid tasks has been discussed [ 7 – 9 ]. To address these issues, we investigated not only the round-trip condition but also the non-round-trip condition by presenting walking movies for relatively long intervals. The duration of a trip in this study was over 20 min, which is closer to typical trip-durations than previous studies. The experimental setup using walking movies is more ecological than that in Seno et al. [ 6 ] and the same as that in Ven et al. [ 4 ]. In one of our unpublished studies, when participants walked on a treadmill during the same experiment setup, they sometimes tried to turn right or left on the treadmill as if they had walked in a real environment. The method of watching a movie presented by a projector in a dimly room seems to have a sufficient sense of immersion, though we acknowledge that watching a movie is different from a real walk. From the viewpoint of duration interval and environment, this study is comparatively ecologically valid.

A second issue is the need for prospective timing for a long real-life interval. Time perception studies are divided into prospective and retrospective timing [ 1 , 10 , 11 ]. Prospective timing is involved in the situation where participants are alerted in advance that timing is an essential part of the task presented, for instance, you are asked to perform arithmetic exercises for a given duration and asked in advance to estimate the duration upon the completion of the interval. This timing depends on attentional processes, as explained by the attentional gate model [ 5 , 7 – 9 , 12 , 13 ]: the attention paid to the duration closes a switch between an intrinsic pacemaker and a pulse accumulator, and time judgment is based on the pulses counted in the accumulator. As a result, the more attention is paid to the duration, the longer time is felt to be. Retrospective timing is the situation where participants are asked an unexpected question about duration, for example, you try to recall how long a film was, or how long it took to talk with friends. Retrospective timing is based on memory processes [ 5 , 7 , 9 , 12 , 13 ], and a larger memory for an event leads to a longer remembered duration. When estimating time, it has been assumed that the amount of segmentation determines the size of a memory as a contextual change model indicates [ 14 , 15 ]: the contextual changes perceived generate temporal referents in memory and we reconstruct the duration of the event based on them. That is, more mental contextual segmentations lead to longer estimation. Ven et al. [ 4 ] used the retrospective paradigm. On the contrary, Seno et al. [ 6 ] used the prospective paradigm, but as mentioned above the duration of the task was very short. Therefore, it is unclear whether the return trip effect is observed in prospective timing for longer, real-life intervals. We adopted two methods of time estimation. One was repeated production of a 3 min interval (RP3), which reflects time perception in real time, or prospective timing. The other method was an 11-point scale reflecting postdictive time perception, or retrospective timing, as it was also used in a previous study [ 4 ]. Using RP3 and an 11-point scale enabled us to evaluate both prospective and retrospective timings within the same experiment. However, it should be noted that we use the terms “time perception in real time” and “postdictive time perception.”

It is important that the return trip effect has been observed when using the verbal estimation method [ 4 , 6 ] and the comparison method [ 4 ]. The estimation method may be a more complex time judgment, because it implies the quantification of duration in time units while the comparison method only requires a comparison between durations [ 8 ]. Regardless of this difference the return trip effect has occurred. In this study, RP3 as the production method and an 11-point scale as the comparison method were used. The production method is compatible with the verbal estimation method [ 1 ]. Based on the observations in previous studies, we hypothesized that the return trip effect would be observed not only in the postdictive rating task but also in RP3.

Studies of time perception have focused on physiological factors such as heart rate (HR), body temperature, or age, as well as perceptual or cognitive factors, in search of fundamental timing mechanisms [ 1 , 10 , 16 ]. Classically the relationship between time perception and body temperature has been well known. The general rationale is that, as increase in temperature facilitates chemical reactions, any physiologically based pulser or oscillator will operate at a faster rate, with decrease in temperature having the opposite effect [ 10 ]. Compared to body temperature, HR may have more complex effects. Jamin et al. [ 17 ] found a linear relationship between time estimation and HR, with underestimation of duration with decreased HR. This seems to be explained by the same rationale as that for body temperature because a decrease in HR may lead to a slower rate of the physiologically based pulser, which can cause underestimation of duration. Lediett & Tong [ 18 ] indicated that increases in HR improved the accuracy of time perception in some participants, but lessened it in other participants, depending on their personality. Though the direction of the effect of HR is unclear, HR can modulate time perception. Moreover, HR can be analyzed in more detail. HR is regulated by the sympathetic and parasympathetic nervous systems; therefore, HR variability (HRV) represented by the standard deviation (SD) includes the influence of both systems [ 19 ]. Analyses such as spectral analysis or the Lorenz plot can separately evaluate these modes of regulation [ 20 – 23 ]. Measurement of HR enables us to use these analyses, which is the advantage over measurement of body temperature.

While these physiological factors that are assumed to underlie timing mechanisms are mainly investigated over relatively short intervals, perception for long intervals is attributed to cognitive processes such as memory or attention. However, it is not denied that physiological factors may also affect time perception for long intervals. HR and HRV seem to be related to cognitive processes as well as autonomic regulation. HR has been found to react to the emotional valences of film clip stimuli while HRV has been found to be related to acoustic startle reflex sensitive to negative stimuli [ 24 ]. It is possible that these physiological responses could not only underlie the oscillator of the internal clock but also modify time perception for long intervals through more complex cognitive processes such as emotion [ 13 , 25 ].

The aims of this study were 1) to compare the round-trip and non-round-trip conditions with a real-life duration and comparatively ecological environment, 2) to identify the circumstances where the return trip effect occurs (i.e., time perception measured in real time or postdictively), and 3) to examine whether autonomic nervous system (ANS) activity contributes to the return trip effect. We hypothesized that the return trip effect would be observed in both RP3 and the 11-point scale, and that differences in ANS activities between the two groups may underlie the return trip effect.

Materials and Methods

Participants.

Twenty healthy males (aged 20−30 years) participated in the study. All participants reported normal or corrected-to-normal vision. The experimental procedures were conducted in accordance with the Declaration of Helsinki and were approved by the Local Ethics Committee of the Graduate School of Human and Environmental Studies, Kyoto University. Participants gave written informed consent according to institutional guidelines.

Procedure and tasks

The experiment consisted of two test sessions: the first trip session and the second trip session. In both sessions, participants were asked to watch a movie recorded while walking. Before each session, they were handed a map of a route they would watch in the movie and instructed to glance at the map during the task as if they actually walked the route for the first time. There were three different movies: movie-1, -2, and -3 ( Fig 1 ). Movie-1 showed a route from “S” to “E” in Fig 1A . Movie-2 showed a route from “(S)” to “(E)” in Fig 1A , which meant that the route was the same as that of movie-1, but the direction of travel was reversed. Movie-3 showed a route from “S” to “E” in Fig 1B , which was completely different from those of movie-1 and movie-2. The durations and distances of the three movies were equal (26.3 min, 1.7 km). A round-trip group, comprising 10 participants, watched movie-1 or movie-2 in each session. A control group, comprising the other 10 participants, watched movie-2 or movie-3 in each session. The order of movies was counterbalanced across participants in both groups. We confirmed that all twenty participants were unfamiliar with the routes they had watched.

‘S’ on the maps denotes the starting point, and ‘E’ the endpoint for each route. Cyan line represents the routes of movies. (A) A route in movie-1 and -2, with ‘S’ and ‘E’ for movie-1 and ‘S’ and ‘E’ with parentheses for movie-2. (B) A route in movie-3.

While watching the movie, participants were required to verbally report when they felt it had taken 3 min, and to continue these reports until the end of the movie (repeated production of a 3 min interval task hereafter called RP3 task). After watching the two movies, they were asked which movie they felt was longer on an 11-point scale from −5 (the first was a lot longer) to +5 (the second was a lot longer). They were not informed of this question in advance. Participants were instructed to remove their wristwatch or any rhythmical devices and not to use verbal nor nonverbal counting strategies such as “1, 2, 3…” during the tasks. Before the experimental sessions, there was a practice session in which participants watched a movie, saw a map, and carried out the RP3 task using a route that was different from those used in the test sessions. There was a rest interval of 10 min between sessions.

The experimenter had recorded four movies (movie-1, -2, -3, and the movie used in the practice session) using a camera (EX-F1, HD/30 fps, CASIO, Tokyo) held in front of the chest while walking. We carefully prepared three experimental movies to precisely match their durations. Firstly, an experimenter who would record the movies practiced walking in order to walk with constant speed. Secondly, we preliminarily searched routes to examine the timings when traffic lights change so that we could adjust the frequency of being stopped by red traffic lights. Finally, we shot each movie four to six times. Based on these efforts, we produced movies with well-controlled durations. The movies used in the first and second test sessions were approximately 26.3 min long, and the movie used in the practice session was approximately 9.0 min long. Movies were played back by a PC and presented on a screen by a projector (NP62, NEC, Tokyo) at a size of 0.9 m × 1.5 m. Participants were individually tested in a dimly lit room and comfortably sat on a chair. The distance between the screen and the projector was approximately 2.70 m, and that between the screen and the chair was approximately 3.65 m. At the start of the movie, a stopwatch was started, and the experimenter filmed the session so that the times of participants’ verbal reports could subsequently be confirmed. To obtain heart beats, a bipolar electrocardiogram (ECG) was continuously measured by a precordial lead. The recorded ECG was stored on a computer via 16-bit analog-digital converter (PowerLab 16SP, ADInstrument, Sydney) at a sampling frequency of 1 kHz.

Data and analyses

Two indices were used to evaluate time perception. RP3 represented the objective durations between the start of the movie and the first report, or between a report and the following report produced by participants in the RP3 task. The larger the RP3, the shorter the participant evaluated the past time was because overproduction in the production method equals to underestimation in the verbal estimation method. This index evaluated time perception in real time because it was produced during the experiment. The other index was the 11-point scale. This index of time perception more closely corresponds with our daily experiences. Also the judgment on the 11-point scale was not processed during the tasks because it was unexpectedly asked in the end. Therefore this judgment was constructed after the tasks.

ANS activity was assessed from the ECG data. Detection of each cardiac impulse was triggered by the R wave, and visual inspection was used to search the possibility of extra or missing beats. Then R-R intervals were calculated from these impulses, and were converted into instantaneous HRs. To investigate overall changes in HR, the mean instantaneous HR and the SD of instantaneous heart rates (SD-HR) were calculated. SD-HR is considered to be an index reflecting the activity of the whole ANS, because the SD of HR reflects all cyclic components responsible for variability, and the variance is mathematically equal to the total power in spectral analysis [ 19 ]. To investigate ANS activity in detail, the Lorenz plot was adapted. This is a two-dimensional non-linear plot. When the sequence of the consecutive R-R intervals is expressed by I 1 , I 2 ,…, I n , the Lorenz plot is constructed by plotting I k + 1 against I k . Two components of the R-R fluctuation are calculated from the plots: the length of the transverse axis (T), which is vertical to the line I k = I k + 1 , and that of the longitudinal axis (L), which is parallel with the line I k = I k + 1 . These components are calculated by quadrupling the SDs of the plotted points along its axis. Two autonomic indices were obtained from these components: cardiac vagal index (CVI) is defined as log 10 (L × T) and cardiac sympathetic index (CSI) as L/T. CVI and CSI reflect parasympathetic and sympathetic functions, respectively. This analysis is more sensitive than spectral analysis [ 20 ].

RP3s were averaged within participants in each session. ECG data were separated into segments corresponding to RP3s. Then HR, SD-HR, CVI, and CSI were calculated in each segment and averaged across segments within participants in each session.

To assess the independent and combined effects of RP3, HR, SD-HR, CVI, and CSI, a two-way mixed-model analysis of variance (AVOVA) was conducted with the round-trip and control groups as a between-subjects factor (Group) and the first and second trips as a within-subjects factor (Trip Session). If a significant interaction was found, within-subjects differences were analyzed for each group using two-tailed pair-wise t tests. To assess the 11-point scale, a two-tailed Welch’s t test was used because of the difference of variance mentioned in Results (see also Fig 2B ). Also, a two-tailed one-sample t test was used for each group to judge whether the estimation was significantly biased. Effect size was estimated by using partial eta-squared ( η p 2 ) and Cohen’s d . Pearson correlations between autonomic nervous activities (the change of HR, SD-HR, CVI, and CSI) and time estimates (changes in RP3, and the values of 11-point scale) were investigated in each group. The change in each index was defined by subtracting the value in the second trip session from that in the first trip session. For all statistical calculations, p <. 05 was accepted as significant. In case of multiple comparisons at follow-up analyses, Holm correction was used to control for false positives.

(A) Mean RP3 in each condition, calculated across participants, and (B) mean 11-point scale in each group, calculated across participants. Values are means ± 1SE. RP3, repeated production of a 3 min interval.

Time estimation

The mean RP3s are plotted in Fig 2A . An ANOVA on RP3 revealed that there was a significant effect of Trip Session ( F (1, 18) = 5.57, p = .03; η p 2 = .24). There was no effect of Group ( F (1, 18) = .13, p = .72; η p 2 = .007) and no significant Trip Session × Group interaction ( F (1, 18) = .84, p = .37; η p 2 = .04).

The mean 11-point scale scores are plotted in Fig 2B . There was an apparent difference in SE between two groups. In the round-trip group the evaluated scores were all negative whereas in the control group the scores included both negative and positive values. Due to this difference we performed a Welch’s t test showing that there was a significant difference between the two groups ( t (12) = −2.92, p = .013; d = −1.31). A one-sample t test showed that the mean score for the round-trip group was smaller than 0 ( t (9) = −6.53, p = 1.1 × 10 −4 ; d = −2.06). In addition, all ten participants produced negative values. The scores on the 11-point scale for the control group did not differ from 0 ( t (9) = .60, p = .57, d = .19).

Autonomic nervous function

Variables related to ANS activities are plotted in Fig 3 . In the round-trip group one participant showed very slow HR (around 55 beats/min) with low variability because he was a skilled sport player, and another showed very fast HR (around 100 beats/min) with high variability, which led to wide distributions of HR and SD-HR within the group ( Fig 3A and 3B ). An ANOVA on HR ( Fig 3A ) revealed that there was no effect of Trip Session ( F (1, 18) = .10, p = .75; η p 2 = .006) or Group ( F (1, 18) = .14, p = .71; η p 2 = .008), and no interaction ( F (1, 18) = .70, p = .42; η p 2 = .04). On SD-HR ( Fig 3B ), there was no effect of Trip Session ( F (1, 18) = 1.77, p = .20; η p 2 = .09) or Group ( F (1, 18) = .77, p = .39; η p 2 = .04), but there was a significant Trip Session × Group interaction ( F (1, 18) = 5.16, p = .036; η p 2 = .22). Two-tailed pair-wise t tests revealed that SD-HR in the second trip session was larger than that in the first trip session for the control group ( t (9) = −3.40, p = .016; d = −.48), and that there was no difference between trip sessions for the round-trip group ( t (9) = .55, p = .59; d = .08). On CVI ( Fig 3C ), there was no effect of Trip Session ( F (1, 18) = .51, p = .48; η p 2 = .03) or Group ( F (1, 18) = 2.30, p = .15; η p 2 = .11), and no interaction ( F (1, 18) = 2.74, p = .12; η p 2 = .13). On CSI ( Fig 3D ), there was a significant effect of Trip Session ( F (1, 18) = 9.47, p = .006; η p 2 = .35), but no effect of Group ( F (1, 18) = .59, p = .45; η p 2 = .03). The Trip Session × Group interaction approached significance ( F (1, 18) = 3.87, p = .065; η p 2 = .18). This interaction was not significant, but t tests showed that CSI in the second trip was larger than that in the first trip session for the control group ( t (9) = −4.130, p = .005; d = −.64), and that there was no difference between trip sessions for the round-trip group ( t (9) = −.70, p = .50; d = −.10).

(A) Mean HR in each condition, (B) mean SD-HR in each condition, (C) mean CVI in each condition and (D) mean CSI in each condition, calculated across participants. Values are means ± 1SE. HR, heart rate; SD-HR, standard deviation of heart rate; CVI, cardiac vagal index; CSI, cardiac sympathetic index.

Correlations

Correlations between ANS activities and time estimates are presented in Table 1 . A significant correlation between the 11-point scale and the change in CVI was found in the control group ( r = .74, p = .014) ( Fig 4A ). The correlation between the 11-point scale and the change in SD-HR approached significance in the control group ( r = .62, p = .054) ( Fig 4B ). No other significant correlation was found in the control group, and no correlations were found in the round-trip group.

(A) Correlation of the change of CVI with 11-point scale for the control group, and (B) correlation of the change of SD-HR with 11-point scale for the control group. The change was defined as subtracting the value in the second trip session from that in the first trip session. ANS, autonomic nervous system; CVI, cardiac vagal index; SD-HR, standard deviation of heart rate.

* p <. 05.

It should be noted that we cannot be confident of the null results of ANOVA interaction effects mentioned below due to low statistical power. Assuming sample size = 10 per group and medium effect size f = .25 equivalent to η p 2 = .06, the statistical power to detect the interaction = .56 (calculated with G*Power 3.1 [ 26 ]).

Discrepancy between the two time estimates

We assessed time perception in two ways, prospective judgment involving on-going temporal production (RP3) and retrospective judgment comprising a comparison of two intervals on an 11-point scale. These two indices apparently showed different results, suggesting that the return trip effect might be caused only postdictively. According to the 11-point scale results, only the round-trip group estimated that the second trip took less time than the first trip. In contrast, the RP3 results indicate that both groups felt that time had been shorter in the second trip session. Considering that the 11-point scale is a similar method for evaluating time perception to that used in previous research [ 4 ] and is also close to the situation in which we experience the return trip effect in daily life, it is certain that the return trip effect is observed at least postdictively. In addition, this difference between the two time estimates suggests that postdictive time perception, measured by the 11-point scale, might not be based on time perception in real time, as estimated by RP3. During tasks, time may be felt to be shorter in the second trip session for both groups, but this would not lead to the same experience of time after completion of the tasks.

The discrepancy between the two estimates can be explained by timing strategies. Time perception includes prospective and retrospective timing [ 1 , 10 , 11 ]. RP3 would be prospective timing because participants were aware of this task during the experiment, and the production method is a major method in prospective timing. The 11-point scale may reflect retrospective timing because it was conducted unexpectedly and postdictively, though participants knew that timing was a major task because of RP3. One of the purposes of this study was to reveal whether the return trip effect is observed when using prospective timing for a long real-life interval. The absence of the effect in RP3 indicates that the return trip effect is not induced in prospective timing. The difference between our results and Seno et al. [ 6 ] also using prospective timing could be attributed to duration intervals because their stimuli were 40 seconds. In addition to the two timing paradigms, Wearden [ 11 ] proposed another one, passage of time. Different from prospective and retrospective timings, which focus on how long a time period lasted, passage of time concerns how quickly time seemed to pass. By intuition, if time seems to pass quickly during an event, the event might be judged as short. However, Wearden [ 11 ] reported that film clip stimuli which seemed to pass more quickly were evaluated equally in retrospective time estimation. Passage of time may be easily influenced whereas retrospective timing appears to be difficult to manipulate. The return trip effect, which was only observed in the subjective scale judgment, may not be a matter of the duration judgment, but of passage of time. The question in the 11-point scale was “which movie they felt was longer” and the answer was for example “the first was a lot longer.” This subjective scale may have been confused with passage of time. To investigate whether the 11-point scale was confused with passage of time, we should compare the postdictive verbal estimation and the 11-point scale with the same setting as the present experiment.

The absence of interaction in RP3 may reflect the specific timing method rather than the timing strategy. Previous studies have observed the return trip effect when using the verbal estimation and subjective scale methods [ 4 , 6 ], which suggests that the return trip effect can be assessed by both the method requiring quantification and that requiring just comparison [ 8 ]. As the production method used in RP3 seems homologous to the verbal estimation method [ 1 ], we had expected the return trip effect in RP3, but did not observe it. One of the possible differences between the production and the verbal estimation methods is a review of past time. In the production method, participants can predict how long they should pay attention to time because the target duration, 3 min in this study, is presented beforehand. On the contrary, in the verbal estimation method participants do not know how long they will measure time; presented durations may be 10 sec, 10 min, or 1 hour. In this unpredictable situation without counting strategies it may be more or less necessary to postdictively review past time after the task. The return trip effect observed in previous studies [ 4 , 6 ] using the verbal estimation may be attributed to the review of past time. The postdictive 11-point scale in the present study also includes the review of past time, which may imply the importance of the review of past time.

It is worth noting that the increase in RP3 in both the round-trip and the control condition in the second session might be attributable to repeated reports. According to interviews after completion of the tasks, participants initially seemed to find the RP3 task to be difficult, but as they continued they became accustomed to the task and found it easier. In general, the durations of simple or dull tasks tend to be underestimated, whereas complex or detailed tasks tend to be overestimated [ 27 – 29 ]. Another possible explanation for the increase in RP3 is that there is a lag before the participant becomes absorbed by the movie. When playing a video game, players often underestimate the playtime, but when playing the game only briefly, they overestimate the playtime because of an “adaptation period” that is required to be fully immersed in the game [ 7 , 9 , 30 ]. Bisson et al. [ 9 ] discussed that the adaptation period might be less pleasant and thus induce overestimation of time. It is also possible to interpret the adaptation period from an attentional perspective: after this adaptation period, participants can be absorbed in the game, which distracts attention from its duration [ 12 ]. According to a model for apparent duration suggested by Glicksohn [ 31 ], apparent duration is a multiplicative function of the size of and the number of the subjective time unit. Externally oriented attention decreases the size of the time unit. In the present experiment, after an adaptation period in which participants might have been absorbed enough into the movie, more attention might have been deployed to the movie (an external stimulus) thereby decreasing the size of the time unit, and thus apparent duration might have been shortened. If the duration of the practice session is extended to fully elicit the possible habituation to the RP3 task or the possible absorption into a movie in advance, the change in RP3 observed in this study might vanish. Also, if absorption causes overproduction (underestimation) in RP3, RP3 while playing a video game could be increased after a certain adaptation period. These approaches could provide informative evidence about the change of RP3.

As mentioned above, the absence of the interaction in RP3 may reflect low statistical power. The difference between the two groups in the 11-point scale measure was very large, so the return trip effect seems to be prominently observed in postdictive time estimation. However, we can’t be confident of the null results of RP3.

Moderately different influences on ANS

The two experimental conditions did not cause drastic, but only moderately different, changes in overall ANS activity. The whole ANS, as measured by SD-HR, was more active in the second trip session only for the control group. Similarly CSI, reflecting sympathetic activity, increased only for the control group. These results suggest that overall ANS activity differently responded for the two groups, mainly as a result of sympathetic activity. Increased HRV is associated with lower mental load [ 32 , 33 ]. However, the increase in sympathetic activity is considered to reflect an increase in mental stress or concentration [ 34 ]. It is difficult to infer the change in mental state in the control group. However, on the basis of the major contribution of sympathetic activity discussed above, it is possible that the control group might have felt greater mental stress in the second session. Watching one trip movie over 25 min was a lengthy task. During the second session participants in the control group might have felt that they would have to watch another long dull movie. In contrast participants in the round-trip group might have been relaxed because they would know it from past experiences of return trips that the return trip would seem short. Here we emphasize only that the combinations of movie-1 & -2 and movie-1 & -3 had moderately different influences on ANS activity.

Influence of ANS activity on time perception

Time perception, estimated postdictively, seems to be related to the parasympathetic activity. When the change in CVI between the two sessions was larger, participants in the control group felt that the session with larger CVI was shorter. The correlation between the change in SD-HR and the 11-point scale showed the same trend. On the basis of the fact that the parasympathetic nervous system activity represented by CVI contributes to ANS activity represented by SD-HR, and the values of r (.74 and. 62 for CVI and SD-HR, respectively), it can be inferred that among ANS activities the parasympathetic activity mainly contributed to postdictive time perception. A recent study investigating the relationship between body signals and time perception suggests that the parasympathetic activity may affect time perception. In the reproduction method a decrease in HR caused by an increase of the parasympathetic activity during encoding of time improved the accuracy of duration reproduction [ 16 ]. In our study we cannot refer to the accuracy of postdictive time judgment, but the significant correlation between the 11-point scale and CVI may correspond to an improvement of the accuracy of time estimation. Participants may have tended to overestimate the duration, and the parasympathetic activity may have improved the accuracy of time estimation. As a result, the parasympathetic activity shortened time estimation and participants felt that the session with larger CVI was shorter. Contrary to the control group, the change in CVI was not related to the comparative judgment on the 11-point scale for the round-trip group. This indicates that the relationship between postdictive time perception and the parasympathetic activity may not be so robust.

At the end of this section we should represent one concern that the significant and nearly significant correlations out of 16 might well be false positives. In the present study CVI showed the significant correlation with time perception, which in part follows previous research [ 16 ] finding the relationship between time perception and the parasympathetic activity. Moreover, it seems reasonable that CVI and SD-HR showed higher r values because the parasympathetic nervous system composes ANS. So the correlations we found may be genuine. Nevertheless more research is need in this issue.

What causes the return trip effect?

Why does the round trip bias time perception? Ven et al. [ 4 ] reported that the return trip effect was observed not only when the return trip was via the route same as the initial trip, equivalent to our round-trip group, but also via a route different from the initial trip. Seno et al. [ 6 ] found that the return trip effect was induced only when self-motion perception was accompanied by a round-trip story. Though these two studies used shorter durations than the present study (7 min in Ven et al. [ 4 ], 40 s in Seno et al. [ 6 ]), their results both suggest that the fact or the awareness of “return” would be necessary for the return trip effect. Our control group did not have this awareness, which supports this idea. If this awareness is systematically manipulated, conditions necessary for the return trip effect might be found.

To interpret the return trip effect in a clearer way, the experimental design should be improved. The round-trip group watched movie-1 and -2 as a round trip while the control group saw movie-2 and -3 as a non-round trip. Due to this design the two groups were looking at different scenery or objects. We preliminarily searched the numbers of corners, distances, sizes of the roads, and traffic volume in order to match the environments of the routes. However, the scenery of the movies the two groups watched was not completely the same. For future research, one of the ways to solve this problem would be to use two sets of round-trip movies, such as pairs of movie-1 and -2, and movie-3 and -4. This design will enable us to make four round-trips and eight non-round-trips by counterbalancing the order and combination. Using this design, we will be able to compare the round-trip condition and the non-round-trip condition with the same scenery.

Also, the ecological validity could be elevated. We used as stimuli real-life intervals and the projection of walking movies, which seem to provide a sufficient sense of immersion. However, this environment is different from a real walk in some ways, for example, a narrow field of vision or the absence of physical activity. There are few studies relating time perception to physical activity, but physical activity may modulate time perception. It has been reported that physical activity lessened the accuracy and the variability of time perception [ 35 ]. In contrast, Tobin & Grondin [ 8 ] found smaller variability of time perception with physical activity than visualizing that activity. The impact of walking as a physical activity should be investigated by using treadmill or a field study.

We investigated the return trip effect in a comparatively ecologically valid situation over a real-life interval. By comparing the round-trip condition and the non-round-trip condition, it was confirmed that the return trip does actually make us feel that time is shorter. Moreover, our two methods of time estimation suggest that the return trip effect does not affect the timing mechanism itself, but rather our feeling of time postdictively. We also examined whether ANS activity measured by ECG is related to time perception. Parasympathetic function is one of the resources for temporal information, although it is not so robust one.

For future research, it would be interesting to test the contribution of the awareness of “return” because this semantic labeling may be a major factor in inducing the cognitive bias of the return trip effect. Moreover, neuroimaging studies could provide insight into how time is perceived in ecological situations.

Funding Statement

These authors have no support or funding to report.

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Unsettled weather returns

FADING SUN TODAY

Enjoy the early sunshine. Clouds will increase, leading to a gray and mild afternoon with highs in the 50s and lower 60s. The best chance for showers will be across central and northern New England during the day. Some patchy, light rain will work into southern New England this evening and tonight, but won’t be widespread.

UNSETTLED END OF THE WEEK

A warm front will pass over the region tomorrow with passing showers. Keep in mind, there will still be plenty of dry times Thursday too.

A cold front will come through Friday morning with the worst of the weather. Heavy rain and gusts to 55 mph will slow down the morning commute. Totals rainfall will range from 1-2″ locally. Behind that front there should be dry improvements for the afternoon while it remains quite blustery.

LONG WEEKEND

Saturday will remain unsettled with abundant cloud cover and a few sprinkles. Although Sunday and Marathon Monday look mild and mostly dry, we’ll need to monitor a fast moving disturbance that could squeeze out a few more drops locally.

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