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Our lab’s paper “Threat Prediction from Schemas as a Source of Bias in Pain Perception” has useful pointers on how to deal with catastrophization and inaccurate perceptions of threat severity.
The paper ( https://bit.ly/39vdiwn , https://bit.ly/2Jry1Xm ) was published in the Journal of Neuroscience. Below are important points from our paper:
Pain intensity is like a barometer of threat: grows if the threat is persistent, lessens when threat abates.
Our brain predicts threats by figuring out things and situations that cause harm to our body/self. We develop concepts about threats.
Interestingly, when we are experiencing some pain, things that signal threat of worse pain, the pain becomes stronger. And when the contextual signals are neutral or positive, we can sometimes go through worse medical procedures feeling no pain.
For uncertain threats, the brain adjusts our pain to allow us to explore and learn and detects how far is ‘too far’; this is how we explore and learn. Of course, for more serious threats (burning your finger) the body responds quickly and this happens through a specific pathway.
We (pain scientists) have some ideas on how this happens and we think it involves specific connections through which the brain, the brain stem, and spinal cord communicate with each other.
Our thoughts on the threat (learned patterns and schemas) play an important role in adjusting the pain response. How the brain does this is not known. And what happens when our thinking about threats is wrong?
The body has an instinctual intelligence that uses sensory inputs from pain receptors to detect the level of threat. Our brain checks our mental schemas (which we have learned) against the sensory evidence from the body to verify the schema.
If our thinking conflicts with what the body is feeling, we should correct it, however, previous studies have indicated that schemas may have a strong influence on pain.
We wanted to test this. So is pain biased more towards the schema (our pre-conceived notion) or the evidence (actual nociceptive input)? We first allowed people to learn a concept that threat level presented in visual cues correctly predicts changes in heat-induced pain on leg
Once the concept was learned, we changed the sensory inputs to the leg to increasing levels of mismatch between expected heat and actual heat (prediction errors).
We measured whether people change their evaluations of pain when the heat applied to their leg is increasingly higher than what the cues predicted. The cues presented were linear, but the heat was less and less linear in relation to the cues.
What is the main contributor to pain experience in a uncertain situation? The linear concept (a simple mental schema) or the sensory evidence from the stimulus on the skin? Is pain signalling the preconceived threat or the actual pain input, or is it a combination of the two?
According to predictive coding theory, it would be expected that the prediction errors will cause the pain ratings to change and become more aligned with sensory evidence (less linear).
Although people did change their assessments of pain, and pain did become somewhat less linear in relation to the changes in cues (0-100), the update was small!
The conceptual threat (cues) influenced their pain perception (bias). Eeven when their body was receiving strong heat stimulus, they felt much less pain. Hence, their thought process was controlling their pain more than the heat stimuli on their bodies.
This bias towards the alterations in conceptual threat (schema) was stronger in people who said that they catastrophize more about their pain on a questionnaire.
People who reported high on a mindfulness scale were actually less affected by the schema. Their responses were less exaggerated (less linear) and closer to the objective reality of what was happening to their body.
We used a stringent statistical test to find that a large network of brain regions was grading its response to heat stimuli based on the level of threat even when the stimulus was of the same intensity. Both pain and brain activity aligned with conceptual threats.
Take home: We deal with threats by amplifying them or we underplay the threats based on what we think about them. If we catastrophize or downplay, then the amplification process starts controlling our perceptions #Covid19, #Coronavirus
Being strongly grounded in our senses, without any pre-conceptions, and learning to see things as they are, can be useful for appropriate threat response in situations like #Covid19, #Coronavirus
We thank all of our collaborators @BIOTICImaging @Dal_Anesthesia and especially Dr.Lim for their valuable contribution and @CIHR_IRSC @NSERC_CRSNG @CRC_CRC @HealthNS @NSHAResearch @DalhousieU for funding and supporting the project.
This work was inspired by and made possible because of the efforts of other pain scientists @torwager @laurenatlas @benosaka @C_Buchel @stephangeuter @Robert_Coghill @VitalyNapadow @Colloca_Luana @kren27 @daspainbrain @massihmoayedi @evp82 @PascalTetro @FocusLab_Turin + more
and the predictive coding and top-down processing mechanism and learning mechanism pioneers @FarlKriston @PhilCorlett1 @summerfieldlab @neuroNJactivist @nathanieldaw @KarlDeisseroth @russpoldrack and @OHBM @OHBM_Trainees and many more people + @cpn_rdc
