Several theoretical frameworks have been proposed to explain the physiological basis of pain, although none yet completely accounts for all aspects of pain perception. Here, we provide a historical overview of the major contributions, ideas, and competing theories of pain from ancient civilizations to Melzack and Wall's Gate Control Theory of Pain.
The current definition of pain, established by the International Association for the Study of Pain (IASP) in 1986, defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of tissue damage, or both.” This definition is the culmination of centuries of ideas and work that have explored the concept of pain.
A number of theories have been postulated to describe mechanisms underlying pain perception. These theories date back several centuries and even millennia (Kenins 1988; Perl 2007; Rey 1995). This review will mainly focus on theories postulated since the 17th century and then provide an overview of current thinking. The four most influential theories of pain perception include the Specificity (or Labeled Line), Intensity, Pattern, and Gate Control Theories of Pain