The chronological passage of the hours, days, and years on clocks and calendars is a steady, measurable phenomenon. Yet our perception of time shifts constantly, depending on the activities we’re engaged in, our age, and even how much rest we get.
Time is happening in the mind’s eye. It is related to the number of mental images the brain encounters and organizes and the state of our brains as we age. When we get older, the rate at which changes in mental images are perceived decreases because of several transforming physical features, including vision, brain complexity, and later in life, degradation of the pathways that transmit information. And this shift in image processing leads to the sense of time speeding up.