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How does the nervous system locate a touch on the skin?

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Compound eye — Senses Vespid wasps (Vespidae), similar to other insects, have compound eyes that consist of thousands of tiny optical units known as ommatidia, which contain light-sensitive photoreceptor cells.

The nervous system localizes touch on the skin through a combination of anatomical arrangement, the distribution of nerve fibers, and complex neural processing.1

Mechanisms of Localization

Receptive Fields: Each sensory neuron serves a specific area of the skin known as a receptive field. These fields overlap significantly, meaning any single point on the skin is typically supplied by multiple nerve fibers—often between 3 and 40—with no two points sharing the exact same pattern of fiber activation.12
Neural Arrangement: Localization depends on the specific arrangement of nerve fibers within the skin and the underlying connective tissue. When a mechanical stimulus indents the skin, it activates these fibers, and the nervous system interprets the location based on which specific fibers are firing.1
Surround Inhibition: To achieve finer discrimination, the nervous system employs a mechanism called surround inhibition. By creating an inhibitory area around an excited area, the system sharpens the contrast of the signal, allowing for more precise localization of the stimulus.1

The ability to distinguish between two points of contact—known as the two-point threshold—varies across the body, being highly sensitive on the fingertips and tongue compared to the back.2