Ignorance can worsen the pain
In a new study coming from Aarhus University, researchers wanted to investigate how the human brain processes pain reactions. Specifically, how your brain perceives pain in the absence of any preconceived expectations of pain stimulation. To do this, researchers chose to focus on harmless thermal stimuli, and the perception of the thermal grill illusion, which could be described simply as the burning sensation felt when coming into contact with something frozen.
“Through computational modeling, we demonstrate that the brain uses a probabilistic predictive coding scheme to update beliefs about temperature changes based on their uncertainty.”
To first set a baseline for expectations, they would prompt the subject with an auditory cue that would symbolize which sensation they would feel. Then they would ask the subject to predict which sensation they would feel, after which they would activate the thermal stimuli, and get the subjects pain rating.
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Findings suggested that the subjects would provide an inflated pain rating, when the thermal stimuli did not match their prediction. As when the subjects would feel that same thermal stimuli, but it corresponded with their prediction, the pain rating would be less. More importantly, the results show that when the brain is unsure on what to expect, it will choose a more cautious approach and prepare for a worse case scenario. Therefor increasing the pain response as opposed to lessening it, in response to its own ignorance.
This study would suggest that our own misinterpretations of life experiences can be intensified based on our own perception, whether that is for better or worse. Influencing our fears and worries into a worse state, than if we had a little more experience or knowledge. Perhaps this is why facing your fears can be so effective? Once the reality of the fear is known to us, all of a sudden, its not so frightening.
References:
Jesper Fischer Ehmsen et al. (2025) ‘Thermosensory predictive coding underpins an illusion of pain’, Science Advances, 11(11). Available at: https://doi.org/10.1126/sciadv.adq0261 (Accessed: 20 March 2025).
Francesca Fardo (2025) Not knowing what to expect can make pain feel worse, Medarbejdere.au.dk. Aarhus University. Available at: https://health.medarbejdere.au.dk/en/display/artikel/usikkerhed-kan-forstaerke-foelelsen-af-smerte (Accessed: 20 March 2025).
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