Thursday, November 15, 2018

Physical Time and Inner Time

William Blake
We know that physical time goes on regularly, but inner time (our sensation of the passage of time) is very variable. The two times do not have to match. Sometimes, watching at our inner time, a minute can look like hours, while in other cases the hours fly away. An English poet, William Blake, expressed it well in a famous poem:
To see a World in a Grain of Sand 
And a Heaven in a Wild Flower, 
Hold Infinity in the palm of your hand,
And Eternity in an hour
(Auguries of Innocence, 1803?)
There is a long history of literary works, in which a character enters aesthetic or religious ecstasy, or simply falls asleep, and on returning to reality discovers that many years have passed, sometimes centuries. This subgenre (called by scholars sleeper legends) has representatives in many literatures. In Spanish literature, it is reflected in the legend of the monk and the little bird, associated with the monastery of Leire. In this legend, a monk who enters in ecstasy while a bird is singing, discovers upon awakening that three centuries have gone by. Among medieval French lays there is a legend about the knight Guingamor, who arrived in a wonderful city and stayed there for three days, but when he left, he found that three centuries had passed. And in the United States literature we have the famous story by Washington Irving titled Rip van Winkle, whose protagonist falls asleep one night and wakes up 20 years later.

Among the many cases of optical illusions, there is one that perplexes researchers, which could shed light on the differences between physical time and inner time. This is the Color Phi experiment or phenomenon, which can be described thus:
A person is placed before a screen, and a blue dot is lighted on the top. When that dot is turned off, the screen is kept dark for 90 milliseconds. At the end of that time, a red dot is lighted on the bottom of the screen. Those subjected to this experiment claim to see a blue light dot that moves down across the screen, and towards the middle of its path changes color suddenly and becomes a red dot.
This experiment poses an important problem, as it seems to be opposed to causality, for the color change from blue to red of the perceived light dot seems to take place before the red dot is lighted on the screen. How does the eye know that the dot will change color and position before it happens?
The philosopher Daniel Dennett used this experiment to deny that there are specific areas of the brain associated with each of our conscious experiences. In contrast, Francisco F. Varela, in an article published in 1999 in volume 879 of the Annals of the New York
The Color Phi Experiment
Academy of Sciences, draws a different conclusion, asserting that this experiment shows that internal time is not isomorphic with physical time, that there are actually two different types of time, and that there is no simple (linear) correlation between them.
Varela argues that, in the inner time of our perception, there are three different types of time scales, different from physical time:
  • The 1/10 scale, where basic or elementary events take place, such as neuron discharge. This scale influences the fusion interval of perceptions, that is, the minimum temporal distance for two independent events to be perceived as different. These intervals usually fall between 10 and 100 msec.
  • The 1 scale, which performs the large-scale integration of perceived events and would not be addressed by isolated neurons, but by assemblies of nerve cells.
  • The 10 scale, which corresponds to our descriptions and narrations.
Varela tries to explain conscious perceptions as an emergent result of the action of those assemblies of neurons, whose existence he postulates, and asserts that our experience of inner time and the present time is linked to the 1 scale, the second one.
For me, on the other hand, all this means that the question is still unripe, and that our knowledge of the neural basis of conscious phenomena is very fragmentary and enormously incomplete.

The same post in Spanish
Thematic thread on Time: Preceding Next
Manuel Alfonseca

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