The Sense of Touch

After a long day at work, you walk in the door and slip off those toe-pinching, heel-blistering shoes. You quickly give yourself a therapeutic rub down and then slip into some warm, fuzzy socks. You give your dog a quick pat, grab a soft pillow and finally flop down on the couch. About the time you get into a comfortable position, you realize you set your drink a bit too far away on the table. This isn't a problem, though. While you focus your attention on the TV screen, you reach over and feel around for your hot cup of tea. Once your hand hits the warm ceramic mug, you realize you're home.

Not more than 15 minutes has passed since you walked through the door, but your sense of touch has gathered millions of bits of information from your surroundings. The pain from your pair of shoes is gone, and soft, fluffy comfort has taken over. A cold, wet kiss from your dog has given way to the warm comfort of the couch and a cup of hot tea. From temperature to texture, your sense of touch has been in constant communication with your brain.

Your somatic sensory system is responsible for your sense of touch [source: Neuro Science]. The somatic sensory system has nerve receptors that help you feel when something comes into contact with your skin, such as when a person brushes up against you. These sensory receptors are generally known as touch receptors or pressure receptors. You also have nerve receptors that feel pain and temperature changes such as hot and cold [source: Biology Web].

If you want to learn more about this complex system, read on to find out how your sense of touch works from head to toe and back again.

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.

Psychology of Touching

You probably already know a hug from a loved one can lower your blood pressure and make you feel valued and important. A firm handshake with a friend can create a connection. How you perceive the hug or handshake, along with how your touch receptors receive the pressure, is rooted in your brain.

There are several basic kinds of touch that you may experience:

Intimate -- Here, your pressure receptors respond to a handshake, hug or kiss. If the person giving the touch is someone you care about, you'll probably feel warm and comforted. Your pressure sensors send the feeling of how hard the embrace is, and your brain interprets the nature of the touch as soothing [source: A.D.A.M.].
Healing or therapeutic -- This type of touch is often associated with massage or acupuncture. Sometimes, the pressure is gentle and meant to soothe sore muscles. Other times, the pressure is deep in order to work out knots. Despite differences in severity of pressure, you likely to be aware that the outcome is healing, so your body allows you to relax.
Exploratory or inquisitive -- We all learn about the world through our sense of touch. Many people test out foods, fabrics or other objects by feeling different textures. Sometimes it's possible to rely solely on the sense of touch. This is why it's easy for you to reach into your bag and find a pair of keys without looking. You know the cold feeling of the metal key and hard smooth feel of your plastic key chain.
Aggressive or painful -- Of course, we all know that touch can also equate to pain if the pressure is too much and the intent is wrong. A handshake that's too firm can be uncomfortable instead of reassuring.

Your sense of touch is not only related to your nerve endings undergoing stimulation; the way you interpret the touch is also important. For lots more information on the sense of touch, see the links on the next page.

Acupuncture

Your sense of touch usually pulls you away from the prick of a needle. But practitioners of acupuncture -- a form of therapy that involves sticking the patient in certain places with very thin needles -- have been poking patients for thousands of years. Acupuncture's origins can be traced back to ancient China. Pin-pricking proponents of acupuncture believe that the correct placement of needles in the patient's skin can restore the body to a healthy balance [source: Mayo Clinic].

The Sense of Touch

Physiology of Touching

Psychology of Touching

Lots More Information

Related HowStuffworks Articles