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 involving pain-related, medication-related, and neutral images, alongside a cued go/no-go Pavlovian Bias 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. Unexpectedly, we did not find evidence of greater active avoidance responses to pain-related images in the chronic pain group. Instead the pattern of results was in the opposite direction to that hypothesised, despite these images being rated as more painful and unpleasant. In the Pavlovian Bias task, chronic pain patients showed exaggerated behavioural suppression in the presence of cues signalling potential monetary loss, which interfered with instrumental responding. This pattern was not explained by general learning deficits or altered reward sensitivity. Together, the findings provide preliminary evidence that chronic pain may be characterised by altered responding to motivationally-salient cues, although replication in larger samples is required. Our results are consistent with the possibility that 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 behaviourally-relevant analogue of avoidance behaviour in chronic pain.