Health Psychology : a Textbook

integrated psychology into the traditional biomedical model of pain and described not

only a role for physiological causes and interventions, but also allowed for psychological

causes and interventions.

Input to the gate

Melzack and Wall suggested that a gate existed at the spinal cord level, which received

input from the following sources:


 Peripheral nerve fibres. The site of injury (e.g. the hand) sends information about pain,

pressure or heat to the gate.


 Descending central influences from the brain. The brain sends information related to the

psychological state of the individual to the gate. This may reflect the individual’s

behavioural state (e.g. attention, focus on the source of the pain); emotional state

(e.g. anxiety, fear, depression); and previous experiences or self-efficacy (e.g. I have

experienced this pain before and know that it will go away) in terms of dealing with

the pain.


 Large and small fibres. These fibres constitute part of the physiological input to pain

perception.

Output from the gate

The gate integrates all of the information from these different sources and produces an

output. This output from the gate sends information to an action system, which results in

the perception of pain.

How does the GCT differ from earlier models of pain?

The GCT differs from earlier models in a number of fundamental ways.

 Pain as a perception. According to the GCT, pain is a perception and an experience

rather than a sensation. This change in terminology reflects the role of the individual

in the degree of pain experienced. In the same way that psychologists regard vision as

Fig. 12-1 The gate control theory of pain

288 HEALTH PSYCHOLOGY