h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I am copying this post from Researcher 47158 and reposting it to a new thread because I think it is FASCINATING!!
I stumbled on it by accident in a really long thread and I think deserves to be shared


"Your question about how we sense time:-
Memory is our ability to organise events that have occurred to us. There is a part of the brain called the hippocampus which is able to distinguish important events from not so important ones and, so to speak press the 'record' button. If something is important, it gets encoded in memory. This part of the brain has, on occasion been destroyed by an attack of encephalitis in a few unfortunate patients. These patients lose the ability to form new memories and can't remember things that happenend to them moments ago. You can place small objects in their hand, they close their fingers round them and when asked what they are holding, they are unable to say. Yet these patients can remember episodes and biographical facts from the time before their illness.

There is also a part of the brain called the suprachiasmatic nucleus (catchy, what? - a nucleus of neurons located above the optic chiasm - the importance of which will become clear in a minute) which is responsible for the setting of the body clock. As you know we rely on a circadian rhythm which is actually 25 hours (experiments with people staying for very long periods in caves have shown this) to time our daily activities. The suprachiasmatic nucleus responds indirectly to the arrival of light. This is achieved by receiving input from the optic chiasm the crossing-over point of stimuli from the retina on their way to the cortex at the back of the brain where visual stimuli are processed. This light stimulus sets the clock back to zero - the start of another day.

The importance of the neurotransmitter (chemicals used to transfer signals in the brain) melatonin in mood regulation has recently been recognised. Its production is governed by our exposure to daylight. The shorter days in winter lead to less melatonin production, in turn leading to depression known as Seasonal Affective Disorder (SAD) in some people. (Affect is psychobabble for mood.)

There is a Basic Rest-Activity Cycle (BRAC) which doesn't seem to be controlled by any particular part of the brain but is important in
understanding psychological time. It runs over a period of about 1.5 hours. Most work activity is based around this cycle; anything caried on for much longer than this seems to become boring, and time seems to drag. When you have sustained period of work, study, listening to relatives, etc to deal with it's a good idea to take a break as the 1.5 hour point comes up.

So there are in fact several brain mechanisms which govern our perception and measurement of time over short, medium and long cycles as well as the vividness and interest of some memories and expriences rather than others.
Hope this is of some, er, interest "

The length of most motion pictures is about 1.5 hours... interesting.
Hitchcock said that the length of a film should correspond directly to the capacity of the human bladder.

Which, if you think about it, depends on whether or not you went out for a few s before the movie

Very interesting indeed, wouldn't it be fun to see if u could reset the human clock, an i thought the VCR was a pain to reset. But honestly, this could be why us humans procrastinate so much on time. Time is what u make it. The human brain has its own time, 25 hours, attention has its own span, 1.5 hours, so all we have to do is destroy every clock in existence and follow what our nature sets us. No more worries about being late for work, my internal clock is 5 minute slow!

But in all honesty, if we could reset the attention span by using light in some sort to reset the biological cycle then we maybe, just maybe, be able to get more people to pass their exams!!! I might look into it myself as i have my exams coming up soon!

Apparently you can treat jet lag with strong doses of light - it resets the pineal gland or something.
Maybe a day lying in the sun will help you with exams - good luck with them

I dunno... I tend to get bored of work in much less than 1.5 hours. Sometimes, I'm bored of it before I even walk in the door!

Could this be, perhaps, some kind of strange relativistic effect?

Boy - do I know that feeling Yep - and it starts when you open your eyes and think "oh sh*t - w*rk again" and you just KNOW that the day is going to be about 38 hours long (and that's just the time that you are AT w*rk)