<P> Tactile - sense - related cortical neurons have receptive fields on the skin that can be modified by experience or by injury to sensory nerves resulting in changes in the field's size and position . In general these neurons have relatively large receptive fields (much larger than those of dorsal root ganglion cells). However, the neurons are able to discriminate fine detail due to patterns of excitation and inhibition relative to the field which leads to spatial resolution . </P> <P> r e c e p t i v e f i e l d = c e n t e r + s u r r o u n d (\ displaystyle receptive \ field = center + surround) </P> <P> In the visual system, receptive fields are volumes in visual space . They are smallest in the fovea where they can be a few minutes of arc like a dot on this page, to the whole page . For example, the receptive field of a single photoreceptor is a cone - shaped volume comprising all the visual directions in which light will alter the firing of that cell . Its apex is located in the center of the lens and its base essentially at infinity in visual space . Traditionally, visual receptive fields were portrayed in two dimensions (e.g., as circles, squares, or rectangles), but these are simply slices, cut along the screen on which the researcher presented the stimulus, of the volume of space to which a particular cell will respond . In the case of binocular neurons in the visual cortex, receptive fields do not extend to optical infinity . Instead, they are restricted to a certain interval of distance from the animal, or from where the eyes are fixating (see Panum's area). </P> <P> The receptive field is often identified as the region of the retina where the action of light alters the firing of the neuron . In retinal ganglion cells (see below), this area of the retina would encompass all the photoreceptors, all the rods and cones from one eye that are connected to this particular ganglion cell via bipolar cells, horizontal cells, and amacrine cells . In binocular neurons in the visual cortex, it is necessary to specify the corresponding area in both retinas (one in each eye). Although these can be mapped separately in each retina by shutting one or the other eye, the full influence on the neuron's firing is revealed only when both eyes are open . </P>

What are visual auditory and somatosensory receptive fields