FP trendSeptember 15, 2020 2:24 p.m. IST
On busy days, we feel like time is not passing fast enough, and on the other hand, the length of a leisure activity feels short. What makes us feel that time is passing or dragging on?
Some neurons in our brain can cause this effect, according to a new study carried out in the Journal of Neuroscience. Research shows that the subjective nature of our experiences is mediated over time by the responses of a group of neurons in the brain ̵
These specialized neurons in the supramarginal gyrus (SMG) of the brain are triggered in response to the passage of a certain amount of time. When repeatedly exposed to a stimulus of a fixed duration, these neurons become biochemically “tired”. Since other neurons continue to function normally, our subjective perception of time is shaped by this contrast between tired and active neurons in the SMG.
The scientists Masamichi J Hayashi and Richard B Ivry used functional magnetic resonance imaging (fMRI) to investigate the biological basis for the subjective perception of time in several human participants. These adult participants were told to look at a visual adapter (a gray circle) 30 times in a row for a period of time. They were then shown a test stimulus and asked to guess the duration for which it was shown. The researchers reported that when the stimulus was shown longer, participants underestimated the time it was shown for; Conversely, if the adapter duration was short, the time was overestimated.
“These results show that the neuronal populations in the right SMG that have been matched over time reflect the subjective experience of the time,” says the abstract of the study.
The study focused on the right parietal cortex, where the SMG is located in the brain, as the region where time is encoded and which is responsible for reflecting our subjective experience of time.