One might guess that the brain uses some sort of all-purpose neural stopwatch to time all durations in the range of a few milliseconds up to a second or so. On the other hand, we might speculate that the brain has a multitude of different neurons or circuits each specialized for detecting a given interval, akin to having a collection of hourglasses—one for each possible interval. To attempt to distinguish between these hypotheses we can ask if, and how, people’s ability to discriminate intervals improves with practice.
