Last updated: Mon, Feb 24, 2025
When behavior is an issue we find psychologists as researchers and as care providers. Ronald Melzack (one of the parents of the gate-control model) is a psychologist by training. Much of the fundamental and applied research into pain and related behaviors has been done by psychological researchers. If you receive pain treatment from a "comprehensive pain clinic" (see Integrated Pain Medicine), you will receive cognitive-behavioral therapy as part of your treatment, either from a psychologist or some other therapist who has been trained to see the world with a psychologist's eyes.
According to Wikipedia's entry about psychology (October 7, 2015), Psychology is the study of mind and behavior.
This makes it a rather ambitious undertaking that subsumes much of art, literature, religion, philosophy, economics, history, and more. That article on "Psychology," as of 10/7/15, is a good introduction if you've never looked into psychology. The article describes some of the problems it has tackled, the approaches it has used, and some notable connections between psychology and the social and political currents that have influenced it, as they have been made apparent by the passage of time. Psychology has a treatment branch with a diverse assortment of philosophies and techniques, only some of which have found their way into pain treatment.
As a science, the purpose of psychology is to discover basic principles rather than to explain everything about human life. However, as a collection of techniques, findings, and viewpoints, psychology can be quite a range of things, depending on the agenda of the psychologist and his or her reference group. So, how should we look at psychology and its participation in questions of pain theory and practice?
Physiological researchers have traced the flow of pain signals into a large number of brain structures—through the brain stem to the hypothalamus and then to the somatosensory cortices, the anterior cingulate cortex (ACC), the insular cortex (IC), the amygdala, the cerebellum, and the prefrontal cortex. These “destinations” for pain signals loop back again to the brain stem, where the system for descending pain modulation resides. The connections and the observed activations during pain suggest that the brain/mind is affected by pain and affects pain in complex ways. (See The Brain's Architecture and its Role in Pain for more information on the pain matrix.)
In the current section I have tried to outline some of the scientific evidence that bears on the question of how psychology and pain are related. The evidence demonstrates clearly, as would be expected, that the mind or psyche is involved in perceptions of pain and in responses to pain. Biological theory suggests that the brain should have some ability to tune pain in and out, and the evidence shows that this is the case. Modern research techniques, including brain imaging, are clarifying how this happens. Laboratory experimenters induce temporary pain and can record how phenomena such as attention, expectation, placebo, and hypnosis affect reports of pain. The limits to these effects, as revealed in the lab, are rather narrow, though the exact limits are as yet unknown. Practices such as Mindfulness Meditation, which seem to be based on these same phenomena, are known to provide significant help to some for extended periods.
Still, the evidence that pain strongly affects the psyche is much more clear than the evidence that the psyche strongly affects pain.
Medical researchers and care providers are motivated by a desire for effective treatments for pain. Such treatments are lacking for many millions. It is to be expected that this desire would see the pain/brain link as an opportunity for effective treatments. I go into the practicability of this in following chapters. For now, I wish to look at the psychology of pain from another perspective: the psychology of those trying to understand pain, whether or not they themselves are afflicted with it.
A physiologist of the nervous system also has something to contribute to our understanding of behavior. Neuroscience tries to construct a model of behavior explicitly grounded in physiology and anatomy. A nerve cell has behaviors that can be studied. A group of nerve cells has behaviors that must emerge from and be limited by behaviors of the constituent cells. Groups of cells form larger aggregations and so forth, until finally we see a detailed view of the integrated system, the human being. (The psychologist, as far as I can make out, includes the behavior of this whole system when he refers to "mind.")
Of course the synthetic/analytic model of physiology doesn't work quite that way. For starters, while we know much and are learning more, we find that the more knowledge we have, the more questions. But beyond this is the sheer complexity of an animal's nervous system. Neuroscientists have almost completely mapped out the connections among the 302 neurons of Caenorhabditis elegans, a simple species of nematode.1 The human nervous system has an estimated 80-90 billion neurons and 100 trillion synaptic connections.2 (That's 100,000,000,000,000.) More neurons than stars in the galaxy...... On top of this, the nervous system constantly changes. Synaptic connections are strengthened or attenuated, grown or pruned. Cells die and are replaced. A model that is both accurate, complete and detailed is simply not in the cards.
Nevertheless, neuroscience/physiology is often able to reveal behavior in detail that is not accessible looking from the outside in. Before their experiments in the mid-60s, various observations had suggested the gate-control model, but there was no proof that the model was a good explanation for them. Now we know that the gate-control mechanism that Wall and Melzack proposed was only a small part and vast simplification of a complex system that regulates pain sensitivity. Due to neuroimaging studies, we know not only which areas of the brain are active subsequent to a pain stimulus, but what sequence they are activated in. Tying all that knowledge to human behavior is still problematic.