'Tired' brain cells may distort your sense of time

From Live Science.com (Sept. 28, 2020):

Time in the brain doesn't follow the steady ticking of the world's most precise clocks. Instead, it seems to fly by at one moment and practically stand still at others. This distorted sense of time may be caused, in part, by brain cells getting tired, according to a new study.

When the brain has been exposed to the same exact time interval too many times, neurons or brain cells get overstimulated and fire less often, the study finds. However, our perception of time is complicated, and many other factors may also explain why time moves slowly sometimes and quickly at others.

We have only very recently begun to understand how our brains perceive time. It was only in 2015, that researchers found the first evidence of neurons whose activity fluctuates with our perception of time. But it wasn't clear if these neurons, found in a small brain region called the supramarginal gyrus (SMG), were keeping accurate time for the brain, or creating a subjective experience of time.

In the new study, the researchers used a "time illusion" on 18 healthy volunteers to figure it out. They hooked participants up to a functional magnetic resonance imaging (fMRI) machine that measures brain activity by detecting changes in blood flow.

The volunteers then went through an "adaptation" period, in which they were shown a grey circle on a black background for either 250 milliseconds or 750 milliseconds, 30 times in a row.

After this, the participants were shown another circle for a set period of time as a "test stimulus." They were then told to listen to white noise for a certain amount of time and asked if the test stimulus was longer or shorter than the white noise. (They used white noise as a reference because an auditory stimulus isn't affected by the visual adaptation but the visual test stimulus is.) [read more]

So, if someone is late to an appointment or meeting can they use that as an excuse? You know, “Sorry, I’m late. My brain cells might have been tired.” Probably not. Also, I wonder if tired neurons possibly could effect other senses too. So, do they eventually go to sleep? May explain Sen. Mitch McConnell’s brain freezes. Good thing he is retiring.