Linking perception to thought

Every perception leaves an afterimage, just like a taste leaves an aftertaste. We can test this easily on ourselves. Stare at a bright light for a few seconds then look away. You can still see its traces. It seems so natural to us that we should have this after-effect, that words should ring in our ears, or that a song should get stuck in our heads.

This simple aspect of our perceptual life leads to some strange results. We’ve all experienced the following: we are sitting in a room and a background noise – the washing machine, a vent, or something else – turns off. We hear it turn off, but the whole time it was on, we had not noticed it. In other words, we hear the silence after the sound.