I recently wrote a short essay for 3Quarksdaily on the three second rule of temporal perception and processing in the human brain. It is comparatively easy to measure the thresholds that our brain uses to create temporal structure, i.e. the minimum time interval required to correctly tell apart the sequence of brief sounds or images. It lies somewhere in the range of 30 milliseconds to 60 milliseconds. If healthy subjects hear two auditory clicks (one in the right ear and one in the left ear) which are only 10 milliseconds apart, they may be able to identify them as two distinct stimuli, but they may not be able to say which one came first.
Temporal integration, on the other hand, refers to combining sensory information and creating the sense of a subjective present or the perception of a “now”. It is not possible to directly measure it, but many observational studies point to a “three second rule” of temporal integration in the brain. One of these studies involved the analysis of poetic meter and was conducted by the chairman of the department in which I used to work when I was a student. The study found that the average time it takes to recite individual verses of poems from all around the world is approximately three seconds. Since each verse (the authors use the more generic term “LINE” to accomodate poems which use a different orthrographic notation or which allow for pauses when reciting long verses) is considered to be an independent unit that is intended to evoke certain poetic “moments”, the authors surmise that the global convergence of verse length may be due to the fact that our brain is most comfortable with three-second intervals to create the sensation of the “now”. This is obviously anecdotal and observational, and not a definitive finding, but it is still fascinating. It does not “prove” that our brain perceives the “now” in three second intervals, but when combined with other cognitive studies of temporal integration, it supports the notion that three seconds may be an important temporal unit for our brain.
The complete essay can be found here: http://www.3quarksdaily.com/3quarksdaily/2013/07/three-seconds-poems-cubes-and-the-brain.html.
You should consider reading some of the original references that are linked in my 3Quraksdaily essay, such as the classic study published in the Poetry magazine, which is (thankfully) open access and can be read by everyone. It is a remarkable example of how a collaboration between a cognitive scientist (my former chairman) and a poet which won a prestigious poetry award when it was published in 1983.
dear sir,
after reading your 3 Quarks Daily essay, I was transported back to my university days, which I concluded in 1999 with a psychology paper on measuring the duration of the ‘subjective now’. It is a different Now than in your article; I was looking for the ‘duration of the shortest single moment’, experienced as indivisible. My own research on the subjective integration of moving images and sound found that asynchronous presentation of, on average, 250 ms is introspectively still reported as synchronous, which is suggestive of quite a large temporal margin for the subjective present moment.
In 1999, unfortunately, I didn’t know of the article http://www.cell.com/trends/cognitive-sciences//retrieve/pii/S1364661397010085?cc=y. It isn’t open access, but if you might have a copy to send me I’d be very grateful.
Thank you for your essay,
KEES Driessen, Amsterdam
HOLLAND
LikeLike
Dear Kees,
Thank you for reading the article and sharing the results of your work. As you point out, the Trends in Cognitive Sciences review is not open access. I think it would be best if you contacted Ernst directly. His email can be found in the academic CV on his website and he may be able to also send you more recent review articles that he has written. In addition to the 3-seconds-work, he has also studied shorter intervals of temporal of perception, which are closer to what you investigated.
Jalees
LikeLike