Physiology of Touching
You probably think of the sense of touch as relating to your skin. After all, you have about 5 million sensory nerve receptors in your skin. But you also can feel pain and pressure inside your body. Think about stomachaches and headaches. Most of your sense of touch, though, comes from external stimulus by way of your skin.
So how does a quick journey from the touch receptors in your skin to your brain happen? When the touch, pain or heat sensors in your skin are stimulated, they send electrical pulses to your neurons, special cells that relay electrochemical impulses [source: A.D.A.M.]. The sensory neurons then act as a relay team, passing along the electrical pulse from neuron to neuron until it reaches your spinal cord. Your spinal cord takes the incoming signal and sends it to your brain. Once the brain receives the signal from the spinal cord, it translates the electrical signal [source: Johns Hopkins].
If your pain receptors have sent a message saying that a pair of tight-fitting shoes has gotten too uncomfortable, the brain knows your body is feeling pain. Your brain signals the muscles in your foot to curl up your pinkie toe away from the pain until you take your shoes off. If you've touched something very cold, your brain knows the cold receptors have been activated; you'll probably shiver in response. Likewise, if you are feeling pressure when you hug an old friend, your brain will sense the pressure of the hug around your shoulders or body.
Your brain can combine messages from your sensory receptors. For instance, when you wrap a heated cotton towel around your body after stepping out of the sauna, you're using both your pressure and temperature receptors. However, how you feel about that action is because of the psychology behind your sense of touch. Read on to find out how your brain might perceive incoming touch in different ways.