Expectancy-driven modulation of pain intensity and perceived damage in a LEGO paradigm
Date
2025
Authors
Mastrangelo, Sophia
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Abstract
Pain is a complex experience influenced by sensory, cognitive, and contextual factors. Misinterpretation of pain as direct evidence of equivocal tissue damage can reinforce fear of movement and hinder patient recovery, making it important to understand how expectations shape pain and harm appraisals. This thesis examined whether expectancy framing alters pain responses to an ecologically valid mechanical threat and whether participants dissociate pain intensity from perceived damage. Sixty healthy adults completed five walking trials across a fixed LEGO board: baseline, unexpected LEGO, expected LEGO, and two randomized cream conditions framed as protective (placebo) or sensitizing (nocebo). After each trial, participants reported immediate and delayed pain and damage ratings (0–10 NRS), while ground-reaction forces and step timing were recorded. Results indicated that pain intensity increased sharply at first LEGO exposure (ΔM = +2.95, ~30% of the NRS scale) and was further amplified by the nocebo frame (ΔM = +1.22). The placebo frame showed no significant effects. Changes in damage ratings were more subtle, diverging from pain intensity. Overall, findings demonstrate that contextual threat amplifies pain intensity more strongly than perceived damage, reinforcing a dissociation between the two and underscoring the importance of expectation in pain appraisal.
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Keywords
Pain, Damage, Perception, Health Reasearch, Neuroscience, Healthy Population, Expectation, Context