Hey Adam,
Thanks for the questions. Pain science is definitely one of my favorite topics to discuss. I want to apologize in advance for the length of this reply but this is a complex topic.
The painful experience is both a conscious experience and has subconscious components. There is emerging research on the topic of balancing these two components via predictive processing (if you are familiar with Baye’s Theorem this would apply).
According to a recent article released by Ongaro and Kaptchuk, a major difference between the biomedical model (sensory input from tissue abnormality = pain) and the Bayesian model (under the umbrella of BioPsychoSocial model) is the following: “……Bayesian models suggest, instead, that perception is cognitively (mostly non-consciously) modulated, and might be best viewed as a process of prediction, based on an integration of sensory inputs, prior experience and contextual cues.”
What does this mean?
The body is receiving relevant sensory feedback constantly throughout the day (bottom-up) and the mind is consciously and subconsciously making predictions about our perceptions of reality (top-down), if for any reason these two are not in alignment then we have a predictive error.
These two aspects of pain perception are likely inseparable and necessary components of our daily functioning. We are consistently making predictions (hypotheses) about the world we find ourselves in and these predictions are based on prior experiences and contextual cues. I’d take the authors’ argument a step further and include the Reinforcement Theory of Learning which states we learn in our environment via exploration and exploitation based on a risk vs benefit analyses. These explorations and exploitations (prior experiences) help us update our predictions and also likely conditions learned behavioral responses (how we deal with pain when we perceive it). Our responses are influenced by anxiety, catastrophizing, depression, etc.
The tricky part about all of this, our sensory input (seeing, hearing, tasting, feeling, etc) can be quite flawed and we may perceive things that simply aren’t there. An easy way to explain this would be illusions. One I like to discuss is when we thought we saw a face on Mars, and began making all sorts of predictions of what that face meant, how it got there, is there other life, etc. Then as our equipment for viewing Mars’s surface improved, we realized it was a rock face, and our hypotheses were wrong. We updated our beliefs about our reality as it relates to Mars. Another way to think about this is well explained by Lori Mosely in this (https://www.youtube.com/watch?v=gwd-wLdIHjs). He discusses a prior experience where a person was walking through a tall grassy area and was bitten by a snake in the calf area. This experience was unpleasant and resulted in a reactionary response of jumping back and grabbing their leg. The experience was novel and threatening coupled with sensory feedback of tissue damage (nociception), which led to the perception pain (note: pain perception is not an absolute in this case). Fast forward 10 years later and the person is walking in a tall grassy area again and something brushes past their leg in the same region and they leap into the air, screaming and grabbing their leg. The person then looks down and notices it simply was a twig. Albeit a very real experience strongly linked to a prior experience and an appropriate behavioral response based on inappropriate perception (sensory input). The likely predictive hypothesis was a snake was biting the area again and the person was in danger but the sensory feedback was inappropriate for such a behavioral response. After the behavioral response, examining the leg and the grassy area with the twig allowed an update of predictions and a realization the person was in no danger.
I’ve said all this to say this, this process is COMPLEX and we are continuing to learn new things regularly. In my opinion, at this time Bayesian predictive processing is likely our best understanding of the topic but it too has faults.
On to the question of the tight spot giving you pain in your back. This likely has to do with a predictive error. There is a quote from the prior paper I was discussing:
“The idea that what we perceive is not the world as it is but our own best hypothesis of it equally applies to the body and subjective bodily states such as medical symptoms. We do not necessarily feel pain – this framework suggests – because we ‘sense’ it directly from the peripheral body. To put it emphatically, we feel pain because we predict that we are in pain, based on an integration of sensory inputs, prior experience, and contextual cues.”
Pain is not out of your control completely. The primary purpose of pain is attentional focus to ensure survival. The tricky part is when we have predictive error (sore spot) that draws our attentional focus in an unnecessary manner then we can use all sorts of distractionary techniques to tone down the noise. Example, massage ball in that specific spot. The downfall of this process is you’ve now conditioned yourself unnecessarily to being aware of the sore spot and the behavioral response of using a massage ball for “relief”. The belief (I have a sore spot and am focused on it) becomes coupled with the behavior (I need a massage ball for relief). This perpetuates the cycle. The massage ball provides relief because it alters your perception to the tissue you are perceiving sore but just because an area doesn’t feel as you are predicting it to feel doesn’t mean there is anything wrong with that tissue that necessitates fixing or a massage ball. Does that make sense?
To your last point, theatrical placebo is a POWERFUL thing. If a provider has therapeutic alliance (strong trust and a team based relationship) with the patient, then almost anything can be utilized as a means to provide perceived “healing” and thus leaving the patient feeling as though their goal of relief has been accomplished. These things are unnecessary because in essence, as it relates to pain, we as clinicians are placebos and the ethical question is how much are we going to maximize our placebo like effects. The push is to condition patients to take care of themselves by guiding their path to their goals and minimizing any unnecessary conditioning to clinicians or interventions. This means we need to pay close attention to our narratives we are providing patients (example the experiencing of sore spots) and interventions. These waters can get even more muddy if we begin attempting to define abnormalities necessitating treatment. Happy to discuss more. Again, my apologies for the lengthy response.