Differential Operant Conditioning of Emotional-Motivational and Sensory-Discriminative Pain Responses.

backgroundThe experience of pain consists of different components, including sensory-discriminative and emotional-motivational components. While these components are often well aligned, they can also dissociate. Operant conditioning may selectively modulate one component without affecting the other. However, evidence directly comparing operant conditioning effects on both emotional-motivational and sensory-discriminative components of pain is lacking. The aim of the present study was to test whether operant conditioning would differentially affect behavioral surrogate measures of emotional-motivational and sensory-discriminative pain responses.

methods62 healthy participants performed in two testing sessions a pain avoidance task to assess emotional-motivational pain responses and a temperature discrimination task to assess sensory-discriminative pain responses (counterbalanced order). In the second half of each task, successful pain avoidance or accurate temperature discrimination was followed by monetary reinforcement.

resultsContingent reinforcement selectively enhanced pain avoidance, evidenced by faster reaction times and increased success rates, while temperature discrimination performance remained unchanged, likely due to a ceiling effect in task difficulty. Operantly conditioned changes in pain behaviour did not generalize to self-reported pain intensity and unpleasantness ratings.

conclusionsThese findings indicate a modulation of emotional-motivational pain processing by operant conditioning, while effects on sensory-discriminative processing remain absent. These results support the idea that enhanced pain perception in chronic pain can be induced by operant learning, potentially through the specific learning of increased emotional-motivational pain responses. SIGNIFICANCE STATEMENT: This study demonstrates that operant conditioning can enhance avoidance responses, serving as an indicator of emotional-motivational pain responses. In contrast, sensory-discriminative aspects of pain were not modulated by operant conditioning. These results confirm the important role of operant conditioning specifically in emotional-motivational pain processing. This insight may help explain how learning contributes to increased emotional-motivational pain processing in chronic pain.