Come and listen to Mick Thacker talking about the One Thing he wants people challenged by pain to know about? Dive into the current state of clinical practice and pain science research in this predictably straight-to-the-point interview with Mick Thacker.
About Prof Mick Thacker
Mick is a Professor at London Southbank University. He is doing a 2nd PhD on the predictive processing model for pain. Here is his research profile.
He encouraged viewers of this video to see his TEDx talk.
And this paper: Friston, K., & Frith, C. (2015). A duet for one. Consciousness and cognition, 36, 390-405. https://doi.org/10.1016/j.concog.2014.12.003
A couple of researchers that Mick suggests you look at checking out if you want to enter the world of Predictive Processing (PP): Abby Tabor, and Andy Clark.
Transcript
Mick, what’s the one thing you want people challenged with pain to know?
I want people to know that pain is a perception not a sensation that’s my one thing.
For many years pain was considered a sensation, largely influenced by the work of a guy called Rene Descartes. He was a French philosopher and scientist. Descartes posited that something happens to you on your body surface for example, and that activates a group of specific (in his case) channels. In later days people thought of specific receptors that transmitted a signal, often called a pain signal, that travels from the periphery up to the brain, rings a bell in the in the brain, and then people feel pain. That’s a basic sort of schema of a sensation.
A perception would posit that whilst we are receiving lots of sensory information from the periphery, you may or may not attend to any of those things. A more modern agenda that I’m involved in is a thing called predictive processing, that posits that what’s happening all the time is you’re trying to predict what sort of sensations you’re likely to come into contact with. Then [you] basically use that information to either confirm or negate those expectations.
But what that overcomes is this idea that you’ve got this line labelled, that you’ve got a flow of information coming in from the periphery and your brain sits there as a cognitive couch potato, waiting for those events, and only then responds to them.
What we now know is that your brain is always making predictions about what’s likely to occur. And in fact, that probably also modifies the way in which you act on the world to try and bring those things that you’re likely to need to pay attention to in line with the predictions. So, you generally change your actions, as well as the internal models of your nervous system. And that lends itself more to this idea that that what you actually feel is much more based on those, if you like, computations between those expectations and then the reality of what’s going on in your sensory world, as opposed to just this pure sort of relaying of sensory information.
So, it sounds like, we’ve got an active brain that’s doing lots of predictions, and computations. How does that translate into a pain experience?
Yes, so a pain experience is essentially under that sort of framework. It’s what makes the best sense for that particular situation for that person, or that animal, and the set of circumstances they find themselves in. So rather than it being a set sensation – a passage of information that begins with pain and ends with pain – it’s actually saying that even things that may not be noxious, may not be damaging, [or] may not even potentially be damaging, can (if the circumstances are correct to confirm a prediction that they may be damaging or potentially damaging) result in pain.
That’s a reason why perhaps patients go to see professionals like ourselves in the clinic and are told by many clinicians, “look we can’t find anything wrong with you. We’ve given you this really detailed examination, but we don’t find anything wrong” – and if you have that old-fashioned idea, you’re stumped. Those clinicians who hold on to the idea of pain as a sensation – it must be coming from something and it must be coming from somewhere – but what we’re really saying is actually circumstances, expectation, anticipation, a threat which might not be physical, could be actually enough to set prediction that a set of circumstances are likely to result in this experience of this thing that we call ‘pain’.
That’s all really cool stuff. So, is there a place for us to intervene, is there a way for us to actually do something?
Most definitely. I would like to rephrase that. It’s not for us to intervene – it’s for us to work with the person. It’s to use the information they’re telling us, their experiences, their actual “lived experience of being in pain” – taking all those things that the people who are suffering will tell you very readily, and actually welcoming them telling you that because they’re informing you. Too often that’s seen as complaining or other words are often used. But actually what they’re doing is informing you, and I think it’s beyond us to try and make sense of everything that the person tries to tell us all in one go. Quite often [that] is too much of a challenge, both for the individual themselves and for us as clinicians.
But I think that we need to start to try to explain some of these more modern principles. The exciting message for me is that: we can treat using quite traditional types of therapies within physical therapy in the periphery, but we can also use more modern therapies. Rather than being one or the other, it’s getting that balance between these predictions and the expectations, in a formalized way, often referred to as “priors” in the hardcore literature. But it’s getting those predictions and the sensory world to match each other. And I think physical therapists are in a perfect position. If they broaden their horizon and engage more with the understanding that the brain does not act as this passive recipient, but is a constantly active agent in the person’s actual lived world, I think that that really offers us a huge potential to try to treat people with a much more focused approach to what they are telling us.
I think the important thing for me as a clinician and seeing people with really complex, often long-term, experiences of pain [is that] they’ve been told so many things. That often produces this real contradiction between what they’ve heard from different people. They’ve been to see someone first, and they get a disc, or it’s a joint or whatever. Then slowly, when those things are ruled out it, becomes your brain. What this does is it for those people is we can try and piece together why those people have said what they did at a particular point in that person’s history. I personally believe that that is actually quite easy to do if you’re broad-minded, I think you can really make sense. It also means that you understand the clinicians they’ve seen and you don’t badmouth them, or shout them down, [which is] important for our professional colleagues but also for the patient.
There’s a lovely piece of work by Karl Friston and Chris Frith, who wrote a paper on a duet called “A duet for one”. It’s all about how predictive processing underpins good, high level communication: “You give a message and if my message is different, then I’ve got to bring my message in line with yours, and you’ve got to bring yours in line with mine a little bit, so we’ve both got to find some sort of middle ground.” I think that is a beautiful way to look at how we might in introduce these sort of ideas, and a really good therapeutic model. We need to move a long way as clinicians, I think, much further towards the patient then they ever need to move towards us. That might be controversial, but I’m going to stand by it. I’ve said it, I’m going to stand by it.
Pain is complex, and it’s complex for everyone. It’s complex for the people experiencing it and it’s complex for those people who are treating it and managing it. It’s been a challenge for all of us to read Pat Wall. For those people who don’t know, I was lucky enough to spend a lot of time in and around Pat’s scientific community. I never forget seeing Pat read the same paper five or six times. [He’s] perhaps one of the brightest people I’ve certainly ever met and if he had to read four or five times, I think it legitimizes all of us having to do that at some stage. It’s I think much like all education, it’s about commitment as opposed to how clever or not clever you are.
Thank you so much for your time.