 | This article may be too technical for most readers to understand. (October 2021) |
Surround suppression is where the relative firing rate of a neuron may under certain conditions decrease when a particular stimulus is enlarged. It has been observed in electrophysiology studies of the brain and has been noted in many sensory neurons, most notably in the early visual system. Surround suppression is defined as a reduction in the activity of a neuron in response to a stimulus outside its classical receptive field.
The necessary functional connections with other neurons influenced by stimulation outside a particular area and by dynamic processes in general, and the absence of a theoretical description of a system state to be treated as a baseline, deprive the term "classical receptive field" of functional meaning.[1] The descriptor "surround suppression" suffers from a similar problem, as the activities of neurons in the "surround" of the "classical receptive field are similarly determined by connectivities and processes involving neurons beyond it.) 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 (or its opposite) 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.
- ^ The classical receptive field refers to a concept of neural behavior that was understood to be invalid virtually from the start. As Spillman et al (2015), quoting Kuffler (1953), "not only the areas from which responses can actually be set up by retinal illumination may be included in a definition of the receptive field but also all areas which show a functional connection, by an inhibitory or excitatory effect on a ganglion cell."