High Quality Content by WIKIPEDIA articles! Surround suppression is an effect seen in many sensory neurons, most notably in the early visual system. It is typically observed in electrophysiology studies of the brain, when neurons do not respond as much when the stimulus is enlarged. Surround suppression is defined as a reduction in the activity of a neuron in response to a stimulus outside its classical receptive field. This nonlinear effect is one of many that reveals the complexity of biological sensory systems, and the connections of properties of neurons that may cause this effect are still being studied. The characteristics, mechanisms, and perceptual consequences of this phenomenon are of interest to many communities, including neurobiology, computational neuroscience, psychology, and computer vision.