Brain
Somatosensory Cortex
Processing touch, pain, and body position
Overview
The primary somatosensory cortex (S1) occupies the postcentral gyrus in the parietal lobe and is the main sensory receiving area for touch-related sensations. It creates a topographic map of the body (the sensory homunculus) where more sensitive areas like the hands and lips occupy disproportionately large cortical areas.
Function
- Processes light touch, pressure, vibration, and texture
- Detects temperature and pain signals
- Monitors proprioception (body position and movement)
- Localizes sensory stimuli on the body surface
- Interacts with the motor cortex to refine movement
Key Facts
- The sensory homunculus shows that fingers and lips dominate the map
- Phantom limb pain arises from cortical reorganization of S1
- Braille reading activates S1 like touch in seeing people
- S1 can be remapped throughout life via neuroplasticity