banner
You are not using a standards compliant browser. Because of this you may notice minor glitches in the rendering of this page. Please upgrade to a compliant browser for optimal viewing:
Firefox
Internet Explorer 7
Safari (Mac and PC)
Post Archive
2018 (0)2012 (3)2011 (73)
December (1)

Robot Insects
Tuesday, December 6, 2011
November (6)October (5)

BRB
Tuesday, October 25, 2011

Women's Intuition
Friday, October 21, 2011

Thinking with your Fingers
Monday, October 17, 2011

Choice
Tuesday, October 11, 2011

On Souls and Confections...?
Tuesday, October 4, 2011
September (7)

On Souls...?
Thursday, September 29, 2011

Beware the False Consensus Effect!
Saturday, September 24, 2011

Your Preferences - Preliminary Results
Thursday, September 22, 2011

Popularity Survey - DO IT FOR SCIENCE!
Tuesday, September 20, 2011

Zietsch's Response to PZ, Laden and Scicurious.
Tuesday, September 13, 2011

The Personality of Cities
Tuesday, September 6, 2011

Discussion #1 - Walking Speed and City Size
Sunday, September 4, 2011
August (6)

People who Doodle Learn Faster = Bullshit
Thursday, August 25, 2011

Good News Everyone!
Tuesday, August 23, 2011

Got the Time? Part II
Saturday, August 20, 2011

Got the time?
Sunday, August 14, 2011

Can Randomness Predict the Future?
Tuesday, August 9, 2011

The House of Psycasm
Sunday, August 7, 2011
July (7)June (6)May (8)

Part 1: Do We Have Freewill?
Tuesday, May 31, 2011

The Open Letter: A follow-up
Tuesday, May 31, 2011

This is a lie, she said.
Sunday, May 22, 2011

MSPaint is mightier than the Sword
Saturday, May 21, 2011

The Art of Indecision
Wednesday, May 18, 2011

Skeptical Checklist 1.1
Friday, May 13, 2011

The Skeptical Checklist 1.0
Sunday, May 8, 2011

Of Chimps, Children and Post-Grads...
Monday, May 2, 2011
April (5)March (5)February (7)January (10)

Magical Thinking: Voodoo, Prayer, Black Cats, and You
Thursday, January 27, 2011

The Art of Character Creation
Tuesday, January 25, 2011

Video Game Morality: Actions inside the box?
Friday, January 21, 2011

Psychobabble goes live!
Tuesday, January 18, 2011

The Trolley Problem: Who cares?
Sunday, January 16, 2011

Podcast delay and misc. Drugs!?
Saturday, January 15, 2011

My very own Natural Disaster
Wednesday, January 12, 2011

A window into your Genetics and Mate Preference?
Sunday, January 9, 2011

Oh sorry, I totally phased out there...
Thursday, January 6, 2011

Porn: A force of Mutual Benefits
Sunday, January 2, 2011
2010 (35)
December (7)

Statistical Pwnage
Tuesday, December 21, 2010

Why you should care...
Thursday, December 16, 2010

The paper of Influence
Wednesday, December 15, 2010

Sharing: Part I - Emotions
Sunday, December 12, 2010

No-one cuts deeper than a Science Blogger.
Thursday, December 9, 2010

Me Meme [Ohh, links now]
Tuesday, December 7, 2010

Half Full, or Half Empty? Well, That Depends on the Shape of the Glass.
Sunday, December 5, 2010
November (11)

What Your Voice Says About You
Tuesday, November 30, 2010

Babushka Blog: A Meta-Blog on ResearchBlogging.
Sunday, November 28, 2010

An Announcement:
Tuesday, November 23, 2010

Willful Self-Deception is Bliss
Sunday, November 21, 2010

Dance, Blogger, Dance!
Friday, November 19, 2010

The Science of Marriage
Sunday, November 14, 2010

The Moon and Antarctica
Thursday, November 11, 2010

Available: One Mentee. Good Condition.
Tuesday, November 9, 2010

Again we are limited by our puny human-ness
Sunday, November 7, 2010

Blogging Carnival - What is Psychopathology?: Origins
Friday, November 5, 2010

*sigh* Psi: A Rebuttal
Wednesday, November 3, 2010
October (12)

The Science of Mind-Reading
Thursday, October 28, 2010

How not to think yourself smart...
Tuesday, October 26, 2010

Welcome to Assassins' League
Sunday, October 24, 2010

TODO LATER. A story of procrastination and forgiveness.
Thursday, October 21, 2010

A man and his words.
Tuesday, October 19, 2010

Little kids, little minds...
Sunday, October 17, 2010

Smoking (maybemightcould) is Good.
Thursday, October 14, 2010

How to stop the Apocalpyse
Tuesday, October 12, 2010

How to trick yourself creative
Sunday, October 10, 2010

Siesta - It sounds like Fiesta, but isn't.
Thursday, October 7, 2010

The Dread Pirate Rift
Tuesday, October 5, 2010

Being Blonde. Natural or otherwise...
Sunday, October 3, 2010
September (5)
Rate This Post
Total votes: 0
Blogger Profile

Psycasm

Psycasm is the exploration of the world psychological. Every day phenomenon explained and manipulated to one's own advantage. Written by a slightly overambitious undergrad, Psycasm aims at exploring a whole range of social and cognitive processes in order to best understand how our minds, and those mechanisms that drive them, work.

My posts are presented as opinion and commentary and do not represent the views of LabSpaces Productions, LLC, my employer, or my educational institution.

Post Tags

m
Blog RSS Feed
RSS Add to My Yahoo Add to Google
Saturday, August 20, 2011

Last week I reported on a strange illusion I had in the middle of the night. Upon waking early in the morning I experienced a sensation where I felt as though I had been asleep for 5 or 6 hours, but had actually only been asleep for an hour and a half. The experience disappeared for about a week, and returned for a single night 8 or 9 days later. I'm pretty sure no-one was sneaking LSD into my milo, so I wanted to figure out what was going on.

I asked people what they thought in my last post. Commenter Beauness said that our timekeeping was regulated by our circadian rhythms. Commenter Kate pointed me in the direction of an article about the Suprachiasmatic Nucleus (wiki link). The SCN plays a role in regulating the circadian rhythms.

Now every school kid knows we have Circadian Rhythms, and that they are basically our 'body clock'. But knowing that isn't very useful. What is a Circadian Rhythm? How does it work? and is it grounded in something beyond our biology?

In my last post I posed three questions that I thought would help illuminate my strange sensation. I'm addressing them here, briefly, as best I can. There's a lot of information I'm trying to synthesize, so please take what I write with a pinch of salt.

How do we keep time?

Circadian Rhythms (as nebulous as that term currently is) regulate our time perception. Biologically, we have a number of 'clock genes' in our bodies that feed information back to, and receive information from, the SCN (Suprachiasmatic Nucleus). These 'clock genes' operate throughout the body, and appear to be somewhat independent of other 'clock genes'.

Not only is the body full of circadian clocks, but recent imaging studies also

show that the molecular clockwork acts autonomously within individual cells

- Hastings, Maywood & Reddy (2008)

The SCN is responsible for taking all this information and co-ordinating it with external stimuli - chiefly, Solar Time. The SCN resides just above the Optic Chiasm, which isn't at all surprising, given that it needs fairly direct access to visual information regarding light / dark cycles.

Now that we know this we can pin down the Circadian Rhythms concept. So far as I can tell, Circadian Rhythms refer to the expression of various bodily hormones that regulate the wake / sleep cycle. The four primary hormones are growth hormone, melatonin, cortisol and insulin (Hastings et al, 2008).The SCN, in co-ordination with the various timing inputs, co-ordinate the expression of these hormones which regulate our sleep/wake cycle.

While my description thus far is (probably) overly simplified, the interesting thing is that we have a dispersed system of 'body clocks' which seem to be regulated by a fairly central entity, the SCN. The bit which escapes me is how do interpret this biological information as the thing TIME. To my mind one need not know what [the] time is in order to feel sleepy or alert; and I partly fail to understand how being sleepy or alert can inform my perception of time (though on a broad scale it seems somewhat intuitive). 

Given this is way outside anything I've read into before, it doesn't necessary equate in my mind that 'big rhythms' (my term) like the Circadian sleep/wake and hormone cycles necessarily inform our perception of smaller values of time. For instance, you can know that you began reading this paragraph ~10 seconds ago, but is it likely that these 'big rhythms' have change sufficiently to inform you accurately about this passage of time. It seems that there is another system that measures these smaller values - the interval timing clock (Kuriyama et al, 2003). As its name suggests, it 'counts' rhythmic signals and allows one to measure smaller amounts of time. However, the paper I found is light on the actual mechanism. However, it has been shown that working memory loads, time of day, body temperature, and mood are modifiers of (this form of) time perception (Kuriyama et al, 2003).

In a study by Kuriyama et al (2003) they found that, in short, diurnal fluctuations (i.e. the time of the testing session) influenced our ability to assess short lengths of time (10-second periods); and our ability was negatively correlated with core body temperature. The paper concludes by suggesting that circadian rhythms seem to play a larger role in short term time assessment than does cognitive load or mood. I find that surprising, but then, we're pretty remarkable organisms. 

Does it differ when we're asleep?

No evidence I have found suggests that these processes vary between sleep and wakefulness. One would expect a difference in what hormones are released, but the process - it seems - remains constant. It's all about the Circadian Rhythms and an endless feedback loop of information.

There are a group of people, who, it's hypothesized, have a warped sense of time regarding sleep. These people are Insomniacs. Insomniacs have trouble sleeping, and it is thought that a major mechanism in the disorder is their time perception. It has been proposed that stress from not sleeping leads to more stress, further preventing sleep. This hypothesis (reasonably untested as it is) postulates that insomniacs:

a) Overestimate time elapsed before falling asleep, and

b) Underestimate the period of sleep they have experienced

It is argued that these misperceptions maintain the insomnia. Tang and Harvey (2005) asked, if these hypotheses are true, then do insomniacs have a general malfunction in time perception, and, if so, is it context specific (i.e. in the bed, in the bed room).

So Insomniacs and a non-insomnia control group were asked to estimate periods of time elapsed between two electronic beeps. The periods were 5 sec, 15 sec, 35 sec, 1min, and 15min. They did this in the lab at different times, and at home about an hour before going to sleep while lying in bed.

Results show no difference between the groups. Which, considering how prevalent the behavioural theory of Insomnia is, I found surprising.

What the hell happened to me?

In short - No idea. I am different to the insomniacs, however - I don't have trouble falling asleep. In fact, I'm a pro. And I wasn't underestimating the period asleep, I was overestimating it. That was the strangest part. I'm pretty sure we've all woken up at some point and felt as though we hardly slept at all. Well, this was the opposite. It was like I was cramming more hours sleep into my time than nature would permit.

I guess I'll have to be satisfied to not know what went on. It was certainly strange, but more certainly, stranger things have (and will) happen. As a general rule of thumb I've learned that unless a psychological phenomenon causes disruption to one's life then it's not a problem. Self-awarness problems aside, I find that particular insight to be fairly elegent. Strange as the event was it was nothing more than a curio. I slept well again afterwards, and it caused me no particular anxiety.

The lesson I've learned (if you can call it that) from my experience and my readings, is that time is not objective. We all know this intuitively, but I think it's interesting to note that our perception of time, on a biological level, is certainly not beyond being tricked and warped - even without obvious cause. Certainly it seems as susceptible to illusion and error as is our perception of optical illusions and our perception of phantom noises.


---

Image ref: http://www.iskcon.net.au/kurma/2011/07/04

ResearchBlogging.org Hastings, M., Maywood, E., & Reddy, A. (2008). Two Decades of Circadian Time Journal of Neuroendocrinology, 20 (6), 812-819 DOI: 10.1111/j.1365-2826.2008.01715.x Tang, N., & Harvey, A. (2005). Time Estimation Ability and Distorted Perception of Sleep in Insomnia Behavioral Sleep Medicine, 3 (3), 134-150 DOI: 10.1207/s15402010bsm0303_2Kuriyama, K. (2003). Circadian fluctuation of time perception in healthy human subjects Neuroscience Research, 46 (1), 23-31 DOI: 10.1016/S0168-0102(03)00025-7

This post has been viewed: 382 time(s)

Tags:   

Blog Comments

Brian Krueger, PhD
Columbia University Medical Center
Rate Post:

Like 0 Dislike

When I was traveling in Finland last week I had the same problem.  I went to bed the night before I had to catch an early flight, woke up thinking I had over-slept only to find that I'd been asleep for an hour.  I was so convinced that couldn't be true that I called down to the front desk for the time.  I'm sure the stress of catching my flight played a significant role :P

Add Comment?
Comments are closed 2 weeks after initial post.
Friends