Speed of Processing in Sensory Systems

Psychologist Irving Biederman suggested the following experiment: Turn the television on without the sound, change channels with your eyes closed and then briefly open your eyes. In all likelihood, your brain can effortlessly analyze the image on the screen, even if you have no idea what will be there. It even seems as though the processing is instantaneous, but clearly this cannot be the case. It certainly must take some time for the information to be processed by the visual system. But how can researchers measure how long it takes to do this processing? And what can such information tell us about the underlying mechanisms? These questions are the focus of this entry.