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Gate Control Theory of Pain

The gate control theory was first proposed in 1965 by psychologist Ronald Melzack and anatomist Patrick Wall. They suggested that there is a "gating system" in the central nervous system that opens and closes to let pain messages through to the brain or to block them.

According to the gate control theory of pain, our thoughts, beliefs, and emotions may affect how much pain we feel from a given physical sensation. The fundamental basis for this theory is the belief that psychological as well as physical factors guide the brain's interpretation of painful sensations and the subsequent response. Many athletes do not experience pain during the intense activity of the game. After the game, when they turn their attention to their injuries, the pain suddenly appears to come from nowhere. Many pain sufferers find that their pain is worst when they feel depressed and hopeless-feelings that may open the pain gate-and that it's not so bothersome when they are focused on doing something that demands attention or is enjoyable. Although the physical cause of pain may be identical, the perception of pain is dramatically different.

Here's how the gate control theory works.

First, sensory messages travel from stimulated nerves to the spinal cord-the body's pain highway. There, they are reprocessed and sent through open gates to the thalamus, the brain's depot for tactile information. Sharp pains, such as a sudden burn, stimulate different nerves than gnawing, dull pains.

Once the nerve signal reaches the brain, the sensory information is processed in the context of the individual's current mood, state of attention, and prior experience. The integration of all this information influences the perception and experience of pain, and guides the individual's response.

The brain's response to these information will determine the extent of pain we get. If the brain sends a message back down to close the gate, the pain signals to the brain are blocked and we experience lower pain. (That message may be carried by endorphins, natural painkillers in the body that are chemically similar to morphine.) If the brain orders the pain gates to open wider, the pain signal intensifies and we can often feel debilitating pain such as migraine headache.