Pain, Behavior, and Psychology

Last updated: Fri, Dec 20, 2024

In How Pain Is Made I reviewed some of the known physiology of pain. In that view of pain, events and conditions trigger nerve cells to fire action potentials. The action potentials propagate and are passed along and modulated until they trigger action potentials in the brain. These action potentials in the brain are believed to cause (in a sense, to be) the sensations that we call pain. Nerves are fired in parts of the brain that are believed to be involved in perception, emotion, and memory. This picture of pain is fairly tidy and is well-supported by masses of research, although many questions remain.

The physiological picture of pain is blurry, though, from another perspective. As a practical matter, very little of the physiology is observable in a live, functioning human with tools that are available to a clinical observer. The observer may instead look to things the subject says and does.

We might imagine that the observer could simply ask the subject about his internal state and receive a reliable response. But even in the best case, the subject's knowledge of his own internal state is incomplete. It is difficult to express. In some cases, the subject may be unable to communicate verbally, may be perplexed or deceived by his own perceptions, or may be motivated to communicate in an unhelpful way.

This limitation would be a problem even if pain treatment were simply a matter of accurate diagnosis. But it isn't. There are no curative treatments for most chronic pain, which of course is why it's chronic, an underappreciated fact of life. Chronic pain causes not just incapacity and internal suffering, but social and behavioral difficulties for the sufferer and those he/she is in contact with.

On top of this, there is evidence that the behavior of the pain sufferer can affect the impact of the pain on himself and others, and can even affect the amount of pain that he/she experiences.

The pain shoots up the spinal cord to the brain, where it turns into behavior. Or, "for psychological reasons," as IASP asserts, behavior indicates pain in the absence of bona fide signals shooting up the spinal cord. Either way, the behavior spills out, and we have to deal with it. Sounds like a job for a Psychologist.

Please read how this situation has been described by some widely-published pain researchers:

Pure pain is never detected as an isolated sensation. Pain is always accompanied by emotion and meaning so that each pain is unique to the individual. The word pain is used to group together a class of combined sensory-emotional events. The class contains many different types of pain, each of which is a personal, unique experience for the person who suffers.

Moreover, pain experience emerges from the dynamic interplay of thought, action, and emotion in context.

The individual's personal history, situational factors, interpretation of the symptoms and resources, current psychological state, as well as physical pathology, all contribute to the patient's response to the question "How much does it hurt?"

The psychological evidence strongly supports the view of pain as a perceptual experience whose quality and intensity are influenced by the unique past history of the individual, by the meaning he gives to the pain-producing situations and by his 'state of mind' at the moment. We believe that all these factors play a role in determining the actual patterns of nerve impulses that ascend from the body to the brain and travel within the brain itself, including his present thoughts and fears as well as his hopes for the future.

In addition to affect being one of the three interconnected components of pain, pain and emotions interact in a number of ways. Emotional distress may predispose people to experience pain, be a precipitant of symptoms, be a modulating factor amplifying or inhibiting the severity of pain, be a consequence of persistent pain, or be a perpetuating factor. Moreover, these potential roles are not mutually exclusive, and any number of them may be involved in a particular circumstance interacting with cognitive appraisals.

Pain-related fear and concerns about harm avoidance all appear to exacerbate symptoms. Anxiety is an affective state that is greatly influenced by appraisal processes; to cite the stoic philosopher Epictetus, “There is nothing either bad or good but thinking makes it so.” Thus, there is a reciprocal relationship between affective state and cognitive-interpretive processes. Thinking affects mood, and mood influences appraisals and, ultimately, the experience of pain.

These quotes all try to convey large ideas in a few words. They are too vague to be good statements of scientific knowledge. One issue that is raised by musings like these is the question of bounding. When we talk about appraisal processes and past history and situational contexts, we're no longer talking about pain. Once signals that originated in sensory receptors arrive in the thalamus and the connected processing centers, in a sense they lose their isolation or uniqueness or special status as pain and are merely and transcendentally who we are. So the study of pain morphs into the study of the mysteries of human nature, and "pain" is an entirely inadequate concept to deal with this.

This situation seems to me not to be any sort of flaw in the scientific or medical approach to pain, but rather a clear reflection of the way the pain system works. One thing to watch, however, is how researchers and care providers conceptualize this situation. There seems to be a continuum of certainty that runs alongside the pain channels, most certain when talking about the physiology of neural receptors, less and less certain as signals affect more-and-more complex neural systems. Do the communications of researchers and medical providers reflect this?

I certainly hope that Gatchel and his associates (quoted above) do not literally believe that nothing is bad if we can convince ourselves that it isn't. If they don't, though, why did they endorse such a statement? Along with the obscurity of these statements, I notice a tendency to minimize the most obvious of ideas: that pain is difficult and stressful to endure. I think this may in part be because of the tendency of pain researchers to expand their implicit definition of "pain" as its broad effects become more evident, rather than looking at pain as an environmental fact in the life of pain sufferers.

I hope to make clear what part of the above statements is supported by scientific knowledge and what part really isn't in the following pages.

These experimental results reflect much that we might expect based on pain physiology. Attention can be focused on pain or distracted from pain. While people share a uniform threshold of sensation, people differ in how much pain they will voluntarily tolerate. People in pain don't like things and have an impulse to withdraw.

Experimental results are clearest in the laboratory, where conditions are least like the pain that this book and its readers are concerned with. There are limits to the experimental effects, both in duration (brief versus ongoing) and intensity. Certainly economy in research inclines toward brevity, and practicality inclines toward low levels of pain. Attempts to establish "control" as a tool against pain run up against the practical and theoretical limitations we have seen. "Distress" as a predictor of pain suffers similar problems: it is not possible to separate the distress of experiencing pain from the distress that a pain sufferer experiences as existing in the external world unless it is possible to measure pain. We have seen that it is not.

Much of the behavior seen in the experimental results is biologically adaptive, and can be explained with little recourse to psychology.

Within this section...

Psychological Analysis of Pain Behaviors (Last updated: Tue, Oct 29, 2024)

Impediments to Psychological Analysis of Pain (Last updated: Thu, Aug 1, 2024)

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Behaviorist Theories of Pain and a Standard Model (Last updated: Wed, Feb 26, 2025)