<p>Part of the difficulty in studying <a href="http://en.wikipedia.org/wiki/Time_perception">time perception</a> is that memory is known to be <a href="http://en.wikipedia.org/wiki/List_of_memory_biases">biased by numerous factors</a> including arousal and salience.  So while people commonly report time slowing down during specific events, it is difficult to differentiate the effects of retroactive memory bias in encoding and recall from actual increased resolution in the perception of time and accelerated physical abilities or mental processes.  For example, <a href="http://en.wikipedia.org/wiki/Epinephrine">adrenaline</a> is known to affect both physical response and memory consolidation.</p>

<p>One hint regarding the plasticity of the brain's actual perception of time comes from the <a href="http://en.wikipedia.org/wiki/Recurrent_thalamo-cortical_resonance#Temporal_binding">temporal binding</a> effect (nice review <a href="https://www.youtube.com/watch?v=BTOODPf-iuc">here</a>).  A variety of experiments show that the brain automatically recalibrates simultaneity amongst different neural processes through learning: That is, the brain processes different stimuli at different rates, but it learns to calibrate those processes so as to create <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4336553/">the illusion</a> that they occur at the same time:</p>

<blockquote>
  <p>At least over a short time frame, our temporal perception of events is
  far from veridical, and multiple timelines are capable of dynamic
  recalibration.</p>
</blockquote>

<p>In other words, there is no single perception of time, time is perceived at different rates by different parts of the brain, and then retroactively synchronized.</p>

<p>A more direct attempt to differentiate memory from perception was done by <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2110887/">Stetson et al (2007)</a>.  In this experiment, subjects were dropped 150 feet with no ropes or parachute - into a safety net.  During the free-fall, they were asked to read numbers flashed on a wrist-watch.  The numbers were flashed at different rates to test whether perception resolution was actually enhanced during the fall.  Despite estimating their fall to take much longer than control subjects not performing this task (corroborating the effect of salience on memory), there was no evidence of increased time resolution:</p>

<blockquote>
  <p>Our findings suggest that time-slowing is a function of recollection,
  not perception: a richer encoding of memory may cause a salient event
  to appear, retrospectively, as though it lasted longer.</p>
</blockquote>

<p>However, this conclusion has been criticized by other authors as the failure to produce an effect on time perception may be due to the experiment not being frightening enough, for only testing visual perception, and that free-fall may actually distract from the reading task.  Evidence from <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3384265/">life-threatening events such as accidents</a> and the <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3950412/">performance of skilled individuals</a> in extreme sports for example, suggests that increased time resolution, physical performance, and cognitive abilities during extremely stressful events may be possible:</p>

<blockquote>
  <p>This evidence supports the suggestion by Arstila (2012) that humans
  possess a specialized hormonal or neurophysiological mechanism for
  high-speed cognition; and that this is activated inadvertently by real
  fear of imminent violent death in accidents, emergencies, and certain
  extreme sports; and may on some occasions be activated intentionally
  by individuals who have trained themselves to do so.</p>
</blockquote>

<p><strong>Edit</strong> (re updated question):</p>

<p>The latter paper - Buckley (2014) - summarizes research on the performance of experienced / trained / skilled individuals.  Accelerated performance (physical and mental) is found in accidents in extreme sports, such as climbers in accidental falls; and in the performance of many physical activities:</p>

<blockquote>
  <p>Less skilled participants perceive only confusion, and are likely to
  freeze, panic, or act in ways which increase danger (Buckley, 2012).
  It is also experience and training which allow skilled exponents of
  many physical arts to achieve feats which appear impossibly fast and
  precise. There are many examples in ball and boardsports, gymnastics,
  acrobatics, dance, martial arts, archery, shooting, swordsmanship, and
  in aircraft, car and motorbike racing and stunt driving.</p>
</blockquote>

CC BY-SA 3.0
2015-05-16T21:45:43.833Z
This is a great high-quality answer, thanks +1. Do you think your concluding sentence also applies to my juggling example, i.e., slowing of perceived time related to practice?
AliceD
CC BY-SA 3.0
2015-05-16T23:34:24.813Z
Yes.  The author lists the following regarding training: "There are many examples in ball and boardsports, gymnastics, acrobatics, dance, martial arts, archery, shooting, swordsmanship, and in aircraft, car and motorbike racing and stunt driving." Not juggling specifically, but I'll include it under ball sports. :-)
Arnon Weinberg
CC BY-SA 3.0
2015-05-17T00:00:11.070Z
many thanks, what an interesting read! Would you mind including your last comment in the answer? One way or another - accepted :) Thanks so much.
AliceD
CC BY-SA 3.0
2015-05-17T01:19:49.630Z
Sure thing boss.
Arnon Weinberg
CC BY-SA 3.0
2015-05-17T10:06:56.560Z
I didn't mean to boss you around, it's just that your last comments were of great value and more importantly, they provided a great fit with the discussion I had with ChristianHummeluhr in the question comments, in that your additional comments provided a uniting view on a seemingly split question. Thanks for adding.
AliceD
CC BY-SA 3.0
2015-05-17T14:36:27.897Z
Buckley 2014 is great. I didn't see the mediation coming (my money was obviously on distinct processes), but it makes sense.
Christian Hummeluhr
CC BY-SA 3.0
2015-05-17T16:26:43.037Z
Oh yeah, that's more of an expression (maybe a difference between Canada and Australia?), "boss" is kind of a term of endearment (ever seen the movie The Green Mile?)...  I certainly didn't take it in a bad way.  Happy to help out.
Arnon Weinberg
CC BY-SA 3.0
2015-05-16T21:25:36.897Z
2015-05-17T01:17:44.960Z
2015-05-17T01:17:44.960Z
Arnon Weinberg
<p>I have had this experience that I fell with my bike on an icy street. During the fall, time seemed to slow down and I had an apparent age-long time window to stretch my hand and safely catch my fall.</p>

<p>A less anecdotal example is the following. Among jugglers I think it is a common phenomenon that once you get the hang of a trick, that at that point one comes to realize '<em>how much time one actually has to catch a ball and throw it back into the air</em>'. (I looked for references, but it at least applies to me, and I remember to have read it in juggling instruction material as well. I can try to find more evidence of this perceived time when needed).</p>

<p>Both examples show that the perceived lengthening of time appear to allow the body to make more coordinated movements within a given amount of physical time.</p>

<p>Now my question is, assuming physical time is constant (barred Einstein's relativity of time when travelling at great speeds):</p>

<blockquote>
  <p>Is it true that <strong>perceived time can change</strong> under the influence of <strong>stress</strong> or due to <strong>training</strong>?    </p>
</blockquote>

CC BY-SA 3.0
2015-05-16T11:28:16.933Z
Time perception is fairly complex and not necessarily a single coherent phenomenon. I think we need to know over what time scale the change you're interested in happens (short?), and possibly whether we're talking about retrospective or prospective measures of time perception.
Christian Hummeluhr
CC BY-SA 3.0
2015-05-16T11:33:18.453Z
@ChristianHummeluhr - the first example is on a very very short time scale and likely to be neurally inferred, or retrospectively perhaps due to the hormonal response? The second example has more to do with hours of practice. I might have to differentiate the question, but it also might rely on a common theme?
AliceD
CC BY-SA 3.0
2015-05-16T11:45:43.400Z
I guess it could always facilitate multiple answers, but off the top of my head, I wouldn't imagine the first and second case are all that connected. IIRC, short scale time perception (TP) changes have to do with localized neural phenomena, while longer term TP changes have to do with more distributed training effects on attention and memory retrieval.
Christian Hummeluhr
CC BY-SA 3.0
2015-05-16T11:58:07.190Z
I don't think you should split it up, and it's certainly not worth a downvote. Personally, I would upvote if you made it clearer what you are interested in for each example, and only then proposed the potential connection between them you see which interests you ("TP can change to allow the body more time to execute motor movements"), rather than stating the examples and going straight to a potential connection which implicitly assumes a single TP process. Just a thought, though, it could be an artifact of my exposure to the TP lit.
Christian Hummeluhr
CC BY-SA 3.0
2015-05-16T12:38:58.887Z
What I have learned (in part) is that perception of time varies with the way that your brain is processing information and is dependent upon focus. When falling, much more focus would go into catching yourself, and I imagine the differences between explicit and implicit memory affect TP quite a bit, since implicit recall seems to work faster than explicit... I.e. juggling becomes a natural-feeling (implicit) movement after much practice. I THINK that your brain becomes more efficient in implicit scenarios, so it SEEMS you have more time. I'm no pro. I have no references. I could be way off.
Reed
CC BY-SA 3.0
2016-08-14T18:00:07.240Z
My answer to your question is "yes". It is based on my own experience and the experiences of others. For example, I and many other people don't like to exercise, but we have to do it for health reasons. We find it to be very boring. So, what we'll do is give ourselves pleasant mental diversions during exercise to make us "forget" that we're actually exercising. Time seems to pass much more rapidly when we do this. When we're done, we feel much less badly about having exercised.
Inquisitive
<perception><time>
Can stress or training influence the perception of time?
AliceD
# Can stress or training influence the perception of time?

(Asked by: username_0 on 2015-05-16)

I have had this experience that I fell with my bike on an icy street. During the fall, time seemed to slow down and I had an apparent age-long time window to stretch my hand and safely catch my fall.

A less anecdotal example is the following. Among jugglers I think it is a common phenomenon that once you get the hang of a trick, that at that point one comes to realize '*how much time one actually has to catch a ball and throw it back into the air*'. (I looked for references, but it at least applies to me, and I remember to have read it in juggling instruction material as well. I can try to find more evidence of this perceived time when needed).

Both examples show that the perceived lengthening of time appear to allow the body to make more coordinated movements within a given amount of physical time.

Now my question is, assuming physical time is constant (barred Einstein's relativity of time when travelling at great speeds):

> Is it true that **perceived time can change** under the influence of **stress** or due to **training**?

**Tags:** perception, time

> **Comments:**
> **username_1**: Time perception is fairly complex and not necessarily a single coherent phenomenon. I think we need to know over what time scale the change you're interested in happens (short?), and possibly whether we're talking about retrospective or prospective measures of time perception.  
> **username_0**: @ChristianHummeluhr - the first example is on a very very short time scale and likely to be neurally inferred, or retrospectively perhaps due to the hormonal response? The second example has more to do with hours of practice. I might have to differentiate the question, but it also might rely on a common theme?  
> **username_1**: I guess it could always facilitate multiple answers, but off the top of my head, I wouldn't imagine the first and second case are all that connected. IIRC, short scale time perception (TP) changes have to do with localized neural phenomena, while longer term TP changes have to do with more distributed training effects on attention and memory retrieval.  
> **username_1**: I don't think you should split it up, and it's certainly not worth a downvote. Personally, I would upvote if you made it clearer what you are interested in for each example, and only then proposed the potential connection between them you see which interests you ("TP can change to allow the body more time to execute motor movements"), rather than stating the examples and going straight to a potential connection which implicitly assumes a single TP process. Just a thought, though, it could be an artifact of my exposure to the TP lit.  
> **username_2**: What I have learned (in part) is that perception of time varies with the way that your brain is processing information and is dependent upon focus. When falling, much more focus would go into catching yourself, and I imagine the differences between explicit and implicit memory affect TP quite a bit, since implicit recall seems to work faster than explicit... I.e. juggling becomes a natural-feeling (implicit) movement after much practice. I THINK that your brain becomes more efficient in implicit scenarios, so it SEEMS you have more time. I'm no pro. I have no references. I could be way off.  
> **username_3**: My answer to your question is "yes". It is based on my own experience and the experiences of others. For example, I and many other people don't like to exercise, but we have to do it for health reasons. We find it to be very boring. So, what we'll do is give ourselves pleasant mental diversions during exercise to make us "forget" that we're actually exercising. Time seems to pass much more rapidly when we do this. When we're done, we feel much less badly about having exercised.  

---

## 1 answers

### Answer by username_4 on 2015-05-16. Score: 9 | Accepted answer

Part of the difficulty in studying [time perception](http://en.wikipedia.org/wiki/Time_perception) is that memory is known to be [biased by numerous factors](http://en.wikipedia.org/wiki/List_of_memory_biases) including arousal and salience. So while people commonly report time slowing down during specific events, it is difficult to differentiate the effects of retroactive memory bias in encoding and recall from actual increased resolution in the perception of time and accelerated physical abilities or mental processes. For example, [adrenaline](http://en.wikipedia.org/wiki/Epinephrine) is known to affect both physical response and memory consolidation.

One hint regarding the plasticity of the brain's actual perception of time comes from the [temporal binding](http://en.wikipedia.org/wiki/Recurrent_thalamo-cortical_resonance#Temporal_binding) effect (nice review [here](https://www.youtube.com/watch?v=BTOODPf-iuc)). A variety of experiments show that the brain automatically recalibrates simultaneity amongst different neural processes through learning: That is, the brain processes different stimuli at different rates, but it learns to calibrate those processes so as to create [the illusion](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4336553/) that they occur at the same time:

> At least over a short time frame, our temporal perception of events is
> far from veridical, and multiple timelines are capable of dynamic
> recalibration.

In other words, there is no single perception of time, time is perceived at different rates by different parts of the brain, and then retroactively synchronized.

A more direct attempt to differentiate memory from perception was done by [Stetson et al (2007)](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2110887/). In this experiment, subjects were dropped 150 feet with no ropes or parachute - into a safety net. During the free-fall, they were asked to read numbers flashed on a wrist-watch. The numbers were flashed at different rates to test whether perception resolution was actually enhanced during the fall. Despite estimating their fall to take much longer than control subjects not performing this task (corroborating the effect of salience on memory), there was no evidence of increased time resolution:

> Our findings suggest that time-slowing is a function of recollection,
> not perception: a richer encoding of memory may cause a salient event
> to appear, retrospectively, as though it lasted longer.

However, this conclusion has been criticized by other authors as the failure to produce an effect on time perception may be due to the experiment not being frightening enough, for only testing visual perception, and that free-fall may actually distract from the reading task. Evidence from [life-threatening events such as accidents](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3384265/) and the [performance of skilled individuals](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3950412/) in extreme sports for example, suggests that increased time resolution, physical performance, and cognitive abilities during extremely stressful events may be possible:

> This evidence supports the suggestion by Arstila (2012) that humans
> possess a specialized hormonal or neurophysiological mechanism for
> high-speed cognition; and that this is activated inadvertently by real
> fear of imminent violent death in accidents, emergencies, and certain
> extreme sports; and may on some occasions be activated intentionally
> by individuals who have trained themselves to do so.

**Edit** (re updated question):

The latter paper - Buckley (2014) - summarizes research on the performance of experienced / trained / skilled individuals. Accelerated performance (physical and mental) is found in accidents in extreme sports, such as climbers in accidental falls; and in the performance of many physical activities:

> Less skilled participants perceive only confusion, and are likely to
> freeze, panic, or act in ways which increase danger (Buckley, 2012).
> It is also experience and training which allow skilled exponents of
> many physical arts to achieve feats which appear impossibly fast and
> precise. There are many examples in ball and boardsports, gymnastics,
> acrobatics, dance, martial arts, archery, shooting, swordsmanship, and
> in aircraft, car and motorbike racing and stunt driving.

> **Comments:**
> **username_0**: This is a great high-quality answer, thanks +1. Do you think your concluding sentence also applies to my juggling example, i.e., slowing of perceived time related to practice?  
> **username_4**: Yes.  The author lists the following regarding training: "There are many examples in ball and boardsports, gymnastics, acrobatics, dance, martial arts, archery, shooting, swordsmanship, and in aircraft, car and motorbike racing and stunt driving." Not juggling specifically, but I'll include it under ball sports. :-)  
> **username_0**: many thanks, what an interesting read! Would you mind including your last comment in the answer? One way or another - accepted :) Thanks so much.  
> **username_4**: Sure thing boss.  
> **username_0**: I didn't mean to boss you around, it's just that your last comments were of great value and more importantly, they provided a great fit with the discussion I had with ChristianHummeluhr in the question comments, in that your additional comments provided a uniting view on a seemingly split question. Thanks for adding.  
> **username_1**: Buckley 2014 is great. I didn't see the mediation coming (my money was obviously on distinct processes), but it makes sense.  
> **username_4**: Oh yeah, that's more of an expression (maybe a difference between Canada and Australia?), "boss" is kind of a term of endearment (ever seen the movie The Green Mile?)...  I certainly didn't take it in a bad way.  Happy to help out.  

---

