New Approaches for the Measurement of Pain-Specific and Domain-General Approach and Avoidance Biases in Chronic Pain

This pre-registered study investigated approach and avoidance processes in chronic pain using tasks that index active avoidance tendencies and behavioural suppression. Chronic pain patients and healthy controls completed an approach–avoidance task (AAT) involving pain-related, medication-related, and neutral images, alongside a cued go/no-go reinforcement learning task using monetary rewards and punishments. Relative to controls, individuals with chronic pain showed an exaggerated approach bias towards medication-related images, despite not explicitly rating these images as more pleasant. In contrast, no group differences were observed in active avoidance responses to pain-related images, even though these were rated as more painful and unpleasant by chronic pain participants. In the reinforcement learning task, chronic pain patients showed exaggerated behavioural suppression in the presence of cues signalling potential monetary loss, which interfered with instrumental responding. This impairment was not explained by general learning deficits or altered reward sensitivity. Together, the findings suggest that chronic pain is characterised by heightened reflexive responding to motivationally salient cues. However, active avoidance of pain-related cues may emerge over longer timescales and involve more cognitive, volitional processes. These results highlight behavioural suppression as a sensitive and ecologically relevant marker of avoidance in chronic pain.