Observational learning and pain-related fear

Chronic pain is one of the major health problems in Western societies, with a prevalence of 19%. Not only does chronic pain account for enormous health care costs and lost working productivity, it also results in an extensive quality of life reduction. An important predictor in the development as well as the persistence of chronic pain problems is pain-related fear. The Fear Avoidance model (FAM) of chronic pain presents a plausible pathway by which people can get caught in a downward spiral of increasing avoidance, disability, and pain. Despite the accumulating research evidence supporting FAM in explaining the interference of pain in daily life, the different pathways to the development of pain-related fear have received scant attention in the pain literature so far. The current project aimed at testing the possibility that pain-related fear can develop via an observational learning pathway, that is through observing others displaying pain behaviour during an encounter with a painful stimulus. For this purpose, a differential fear conditioning paradigm was used in several experimental studies with healthy participants. One of two formerly neutral stimuli (CS+ colour) was associated with painful facial expressions of models presented via video clips, while the other stimulus (CS- colour) was always paired with relaxed expressions of models. Observational learning was predicted to occur when the former stimulus acquired a threat value and elicited defensive responses by the participant, while the latter stimulus preserved its neutral valence. Second, we were interested in the extinction of observationally acquired pain-related fear after direct exposure to the conditioned stimulus. Third, we wanted to investigate the putative moderating effects of observers characteristics in order to identify individuals who are at heightened risk of developing pain-related fear through observational learning. We expected pain catastrophizing, trait fear of pain, negative affectivity, intolerance of uncertainty, and dispositional empathy of the observer to facilitate observational learning processes. Results revealed that watching others in pain induced pain-related fear, and caused participants to expect higher pain unpleasantness, pain intensity, and perceived harmfulness regarding the CS+ compared to the CS- stimulus. These beliefs did, however, not always result in changes in behaviour or in changes in psychophysiological responses. Further research is needed to identify the conditions under which these changes do occur. When using a differential cold pressor task (CPT), pain-related fear persisted until the end of the experiment, whereas no differences between CS+ and CS- were found after direct exposure to coloured warm water tasks or cold metal bars. No unequivocal pattern was found across the experiments regarding the possible moderators. The results of this project not only enhance our understanding of the acquisition of pain-related fear, it may also have implications for the development of prevention and cognitive-behavioural management strategies for patients with chronic pain.status: publishe