Try this exercise: Put this book down and go look in a mirror. Now move your eyes back and forth, so that you’re looking at your left eye, then at your right eye, then at your left eye again. When your eyes shift from one position to the other, they take time to move and land on the other location. But here’s the kicker: you never see your eyes move. What is happening to the time gaps during which your eyes are moving? Why do you feel as though there is no break in time while you’re changing your eye position? (Remember that it’s easy to detect someone else’s eyes moving, so the answer cannot be that eye movements are too fast to see.)
All these illusions and distortions are consequences of the way your brain builds a representation of time. When we examine the problem closely, we find that “time” is not the unitary phenomenon we may have supposed it to be. This can be illustrated with some simple experiments: for example, when a stream of images is shown over and over in succession, an oddball image thrown into the series appears to last for a longer period, although presented for the same physical duration. In the neuroscientific literature, this effect was originally termed a subjective “expansion of time,” but that description begs an important question of time representation: when durations dilate or contract, does time in general slow down or speed up during that moment? If a friend, say, spoke to you during the oddball presentation, would her voice seem lower in pitch, like a slowed- down record?
If our perception works like a movie camera, then when one aspect of a scene slows down, everything should slow down. In the movies, if a police car launching off a ramp is filmed in slow motion, not only will it stay in the air longer but its siren will blare at a lower pitch and its lights will flash at a lower frequency. An alternative hypothesis suggests that different temporal judgments are generated by different neural mechanisms—and while they often agree, they are not required to. The police car may seem suspended longer, while the frequencies of its siren and its flashing lights remain unchanged.
Read more: Brain Time
