Receptive field

Under a receptive field is defined as the range of sensory receptors, which passes information to a downstream single neuron.

Very often the term is used for areas on the retina of the eye. Many photoreceptors converge here on a few ganglion cells. A total of about 126 million receptors converge to one million retinal ganglion cells.

The convergence has four important factors:

  • Reduction: The flood of incoming information is reduced so that the signals can be processed more easily.
  • Visual acuity: Approximately 120 million rods and six million cones converge to one million ganglion cells. Thus, the receptive fields of cones are much smaller and thus the visual acuity greater for them. The approximately 60,000 cones in the fovea take it a special role because they do not converge, but to project directly to their "own" ganglion cells. Therefore, the fovea is the site of sharpest vision, while the receptive fields are larger towards the periphery of the eye back and the visual acuity is less.
  • Higher sensitivity, because an incoming signal can be enhanced by light convergence ( a neuron receives input of a plurality of receptors ), the sensitivity at the higher convergence is greater (see the spatial summation). With the larger receptive fields in the periphery therefore so does the ability to perceive movements, too.
  • Specificity: By convergence downstream neurons are activated only when the signal excites a certain activation region of the cell 's receptive field. If only a minor or another part of the cell 's receptive field stimulated, the signal can remain subliminal.

Many receptive fields can be divided into a center and an environment. Mostly these are connected opposite, so that one speaks from the so-called center environment antagonism. There are two major types of fields:

For example, the environment of on- center neuron illuminated, thus causing the inhibition of the signal ( the so-called lateral inhibition). A receptive field speaks perfectly to a stimulus that excites only the center. The purpose of such interconnections is the higher contrast ability of the eye. This allows, for example, object edges are better perceived.

Credentials

Goldstein, E.B. (2002). Psychology of perception. Heidelberg: Spektrum.

Photoreceptor cell Fovea centralis
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