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What is the basis for a person's ability to navigate in time? It is generally accepted that not on external indicators, for example, the interchangeability of day and night, but on the indicators of its internal "clockwork". The great physiologist-experimenter IP Pavlov once came to the conclusion, which was later joined by L. Lyapik, Yu.P. Frolov and other scientists that "the basis of time counting in the central nervous system lies in the change of excitation and inhibition, which is "the most basic clockwork."
Many physiologists of the second half of the twentieth century agreed that the organ responsible for the perception of time in a person is the hearing aid. A person (and possibly other animals) with the help of the ears better and more accurately estimates the time intervals (rhythms, change of stimuli) than with any other known sense organs.
To the conclusion that the "chronosensor" is inside the person, among others, the Indian chronobiologist M.K. Chandrashekaran came who studied the problem for 40 years at the Center for Advanced Scientific Research named after J. Nehru in Bengaluru and only in the 1990s years has openly stated this. In his opinion, modern biologists are on the verge of discovering a gene mechanism working on the principle of clock. The conclusion about the presence in the chromosomal recruitment of a human gene responsible for orienting in time was made in 1994 on the basis of experiments on mice, in which, as is known, about 60% of the chromosome set is similar to the human one.
The next important step was the experiment with a 24-year-old girl, who for 35 days was completely isolated from the outside world. The order of food, sound background, the situation was completely arbitrary and did not depend on real time. In particular, when the girl asked for food, she pressed a button corresponding to breakfast, lunch or dinner. As a result, after the end of the experiment, her "internal clock" measured 22 days instead of actually passed 35, that is, the biological rhythm of the alternation of sleep and wakefulness shifted towards lengthening. At the same time, observations allowed scientists to make an unambiguous conclusion about the independence of menstrual cycles from the rotation of sleep and activity in women.