A solitary figure walks on the beach at dawn. Although he is alert to his surroundings, his sensory systems take in only a fraction of the energy that envelops him. That which does reach the receptor cells is captured and converted into signals that can be recognized by the central nervous system. The ultimate destination for these signals is the cerebral cortex. In this interview based program, neurological experts such as Tom Albright, Christof Koch, and Gilles Laurent, examine the ways sensory receptors take in stimuli as well as how the brain processes and ultimately translates these signals into useful information.