Time, this finite and constructing resource that guides our lives, gives scientists a lot of trouble.
The perception of the passage of time is felt differently depending on the activities you carry out. It seems to you that time passes harder when you are waiting or doing a task that you do not like and, at the same time, time passes so quickly when you do something that makes you happy.
But the question comes: Why does time fly when you have fun?
In a recent study, the researchers came one step closer to answer this question.
By studying the activity of the human brain during tasks in which time is manipulated, scientists have discovered that there are time-sensitive neurons that are triggered in response to a certain period of time.
These neurons are located in the right parietal cortex, which is also involved in the perception of space and movement.
When exposed to repeated stimuli that last the same amount of time, these time-sensitive neurons can wear out. Meanwhile, other neurons continue to function normally, creating an imbalance that eventually distorts the perception of time.
How was the study conducted?
To discover how the brain creates time experience, Masamichi Hayashi and his team used functional magnetic resonance imaging (fMRI) to measure brain activity while 18 healthy adults engaged in a time-comparison task.
This technology measures the small changes in blood flow that occur during brain activity.
“While people have sensory organs designed to perceive visual lights or the tone of sounds, there is no specific organ for the perception of time,” explains Hayashi.
“This means that our sense of time is probably the product of our brain activity.”
In the task of comparing time, participants saw a gray circle on a screen for a set duration, 30 times in a row. This was considered the adaptation period.
Participants then estimated how long it lasted, indicating the “adapter duration”. After this initial adjustment period, the group was presented with a test stimulus, a new item on the screen, and they estimated the time again.
This adaptation procedure allowed the researchers to manipulate the perceived duration, while maintaining a constant physical duration.
What were the results of the study?
When the duration of the adapter (gray circle exposure time) was long, participants underestimated the duration of the test stimulus. In contrast, if the duration of the adapter was shorter, participants overestimated the duration of the test stimulus.
When the adapter and test stimulus were similar in length, activity in the area of the brain responsible for time perception decreased, suggesting that the person’s neurons became tired.
Distortion of human time was correlated with decreased activity in the right parietal cortex. The more tired the neurons were, the worse the participants’ results in terms of estimating time.
These results suggest that researchers could manipulate people’s subjective sense of time by stimulating time-sensitive neurons. Until then, people will have to find other ways to spend time in the waiting rooms and hope that their neurons will not get too tired.