How does the brain memorize time?

In a driver who is skilled in driving a car, it becomes something that you can understand how many seconds you will become a red light after a number of seconds after the green light turns yellow. This means that the human brain has "ability to grasp time", but how the brain knows the time remains a mystery. According to research teams such as psychologist Howard Aichenbaum et al. "Ability to grasp time" takes on "memory"HippocampIt seems that it was demonstrated in an experiment using animals that there is a high possibility that it is functioning with animals.

Time and space in the hippocampus. - PubMed - NCBI
https://www.ncbi.nlm.nih.gov/pubmed/25449892

New Clues to How the Brain Maps Time | Quanta Magazine
https://www.quantamagazine.org/new-clues-to-how-the-brain-maps-time-20160126/

Experiments conducted by Research Team et al., Acesbaum et al.treadmillRepeating giving a reward when running in, it was to see if the rat could acquire time sensuously. For example, if we set the time we need to run to get reward to 15 seconds and repeat the task a number of times, it seems that the rat finally got to understand the 15 second time interval. At this time, it was revealed that when the state of the hippocampal neuron was confirmed, the neuron firing lasted for 15 seconds in a specific pattern.


It was confirmed that neuron firing was accurate enough to predict how many seconds the rat was on the treadmill just by observing which neurons were activated. Furthermore, it seems that the experiment was carried out by changing the speed of the treadmill, but it was confirmed that it was not affected by the speed change and had no effect on the running time of the rat. This indicated that the neuron did not check only the distance traveled. At this time, it was confirmed that the hippocampus generates the firing pattern of the neuron applied to the new interval even if changing the running time to give the reward, and it was confirmed that it can respond flexibly to the change of the condition.

It is also clear that these neurons rely on "environment". Neurons will be activated with a fixed pattern if it becomes a scene where rats need to measure time with a pattern once memorized. However, when other conditions are added, it seems to behave differently even if it is the same neuron. For example, when a rat is searched after transferring it to a new environment, it is confirmed that a new firing pattern will be built for these neurons, and neurons will fire with different patterns depending on the location It was.


In the past many researchers have identified brain regions related to "exercise", "memory", "color vision", etc. However, the place to grasp the time was not specified. And even considering the results of studies presented so far, many researchers are critically looking at Acesbaum's research as "Kaiba is hard to believe that time is understood." I will.

It is known that hurting hippocampus often makes new memory generation and time memory difficult. In the pastRobotomyUndergoing surgery, inside the hippocampusTemporal lobeOf patients known for resectingHMMr. is posting surgery to the attending physician as a self-introduction every day several times, and it is recorded that it got into memory disturbance. Many of the patients including Mr. HM also said that it became difficult even to memorize things and their order.

Eichenbaum concludes that even though these patient cases are taken into consideration, "Hippocampus is likely to be related to both" memory "and" time ".