Physiological Mechanisms of Adaptation in the Visual System

This chapter considers the physiological mechanisms that drive adaptation at higher processing levels in the nervous system. It discusses the mechanisms that generate beneficial alterations in the way that contrast and motion are coded, both of which require several levels of processing beyond the photoreceptors. Adaptation to contrast and motion is normally observed as an alteration in the visual perception of those attributes following prolonged exposure to a given visual stimulus. Perhaps the most striking example of higher-level adaptation in the visual system is the motion aftereffect (MAE). Following exposure to a stimulus moving in one direction, a stationary pattern appears to move in the opposite direction.