Why can different locations on the skin be distinguished by their patterns of active nerve fibres?

The ability to distinguish between different locations on the skin relies on the specific arrangement of nerve fibers and the overlapping nature of receptive fields.1

Because any given point on the skin is supplied by multiple nerve fibers—typically at least three and sometimes as many as forty—no two points on the body surface are served by the exact same pattern of active fibers. This unique combination of inputs allows the nervous system to localize stimuli with precision.1

Furthermore, this discriminative ability is enhanced by several physiological mechanisms:

• Overlap: The extensive overlap of receptive fields for individual nerve fibers ensures that sensory information is integrated across adjacent areas.2
• Surround Inhibition: This mechanism creates an inhibitory area around an excited region, which sharpens sensory discrimination by enhancing contrast.1
• Hierarchical Processing: As sensory information travels from the skin to the thalamus and the cerebral cortex, the brain maintains a precise, point-for-point representation of the body surface, allowing for the accurate identification of stimulus location.2