Final answer:
Neurons at the center of a receptive field inhibit those at the edge to discriminate the location of touch, a process known as lateral inhibition. This is key for high spatial resolution in areas like the fingertips and is tested using two-point discrimination tests.
Step-by-step explanation:
To help discriminate the location of a touch stimulus, neurons at the center of the receptive field can inhibit those at the edge, a process known as lateral inhibition. This mechanism enhances the precision with which we can detect where we have been touched, contributing to a more accurate sensory perception. For instance, this is particularly important in the fingertips where the density of sensory endings is high and high spatial resolution is required for fine touch. Two-point discrimination tests utilize this principle by measuring the minimum distance at which two touch points are perceived as separate; when the sensory regulation, including lateral inhibition, is working effectively, the points will be correctly identified as distinct stimuli.
Receptive fields vary greatly across different sensory modalities. For example, the receptive field for touch requires direct contact with the skin, while for hearing and vision, stimuli can be detected from varying distances. Lateral inhibition plays a crucial role in the sensory processing of these different receptive fields by ensuring that only the most salient stimuli lead to a strong neuronal response, helping to reduce the response to less significant stimuli around the edges of the receptive field.