The somatosensory cortex is the region of the parietal lobe that registers and processes body touch, temperature, pain, and proprioceptive information. It lies on the postcentral gyrus, immediately behind the central sulcus.

The area contains a systematic map of the body, the sensory homunculus, in which the size of each region reflects the density of receptors rather than the physical size of the body part. The lips, tongue, and fingers occupy disproportionately large territories. Information arrives from the thalamus after ascending through the spinal cord and brainstem. Adjacent cortical areas further process the features of tactile stimuli and integrate them with motor and spatial information.

Damage to the somatosensory cortex can produce numbness, impaired localization of touch, or difficulty recognizing objects by feel. Plasticity allows the map to reorganize after injury or after prolonged changes in sensory experience, such as the expanded representation of a musician’s fingers.

Every touch, ache, and sense of limb position is registered first in the somatosensory cortex.