As sensory receptors in our skin, muscles, bones, joints and organs are triggered by a specific stimulus, this signal passes to the somatosensory region in the brain which is uniquely attributed to that area on the body. This produces sensations such as touch, temperature, pain or body position and allows us to feel the processed stimulus at the correct location. The point-to-point mapping of body surfaces in the brain is essential in the construction of our body image. In the somatosensory cortex, the disproportionate representation of our head and hands for example - which take up nearly half of cortical processing - is an important evolutionary advantage. In case of stroke or injury, dramatic shifts can occur in somatosensory mapping.

The somatosensory system