Generalization and extinction of concept-based pain-related fear

In chronic pain, pain-related fear seems to overgeneralize to safe stimuli, thus contributing to excessive fear and avoidance behavior. Evidence shows that pain-related fear can be acquired and generalized based on conceptual knowledge. Using a fear conditioning paradigm, we investigated whether this concept-based pain-related fear could also be extinguished. During acquisition, exemplars of one action category (conditioned stimuli; CSs) were followed by pain (CS+; e.g. opening boxes), whereas exemplars of another action category were not (CS-; e.g. closing boxes). Participants reported more pain-related fear and expectancy towards exemplars of the CS+ category compared with those of the CS- category. During generalization, fear and expectancy spread to novel exemplars (generalization stimuli; GSs) of the CS+ category (GS+), but not to those of the CS- category (GS-). During extinction, exemplars of both categories were presented in the absence of pain. At the end of extinction, participants no longer reported elevated fear or expectancy towards CS+ exemplars compared to CS- exemplars. These findings were not replicated in either the eye-blink startle, or skin conductance measures. This is the first study to demonstrate extinction of concept-based pain-related fear, thus providing evidence for the potential of extinction-based techniques in the treatment of conceptual pain-related fear.

PERSPECTIVE: This study demonstrates the acquisition, generalization, and extinction of concept-based pain-related fear in healthy participants. These are the first results to show that concept-based pain-related fear can be extinguished, suggesting that conceptual relationships between fear-inducing stimuli may also be important to take into account in clinical practice.