Touch is one of the five senses. Called the somatosensory—or body-sensing—system, tactile signals stimulate excitatory neurons which carry their messages through the central nervous system (CNS) to the somatosensory cortex in the brain. The sensory cortex is like an extremely intricate map of every sensory neuron in the entire body; fingers, legs, feet, organs--each one having a cluster of neurons in a very specific area of the cortex. There is a left and right cortex, each servicing the opposite side of the body. Damage to a specific part of the cortex will inhibit sensation from and movement in it's relative body part.

Touch is determined by sensory receptors designed to respond to specific stimuli. Exteroceptors, located primarily in the skin, include free nerve endings, which respond to touch, pressure, itching, temperature, and pain. Merkel's discs, found in extremely sensitive areas such as the fingertips...