«The days of thinking of time as a river—evenly flowing, always advancing—are over. Time perception, just like vision, is a construction of the brain and is shockingly easy to manipulate experimentally. We all know about optical illusions, in which things appear different from how they really are; less well known is the world of temporal illusions. When you begin to look for temporal illusions, they appear everywhere. In the movie theater, you perceive a series of static images as a smoothly flowing scene. Or perhaps you’ve noticed when glancing at a clock that the second hand sometimes appears to take longer than normal to move to its next position—as though the clock were momentarily frozen.

More subtle illusions can be teased out in the laboratory. Perceived durations are distorted during rapid eye movements, after watching a flickering light, or simply when an «oddball» is seen in a stream of repeated images. If we inject a slight delay between your motor acts and their sensory feedback, we can later make the temporal order of your actions and sensations appear to reverse. Simultaneity judgments can be shifted by repeated exposure to nonsimultaneous stimuli. And in the laboratory of the natural world, distortions in timing are induced by narcotics such as cocaine and marijuana or by such disorders as Parkinson’s disease, Alzheimer’s disease, and schizophrenia.»