Associative fear learning and perceptual discrimination: a perceptual pathway in the development of chronic pain.

Recent neuropsychological theories emphasize the influence of maladaptive learning and memory processes on pain perception. However, the precise relationship between these processes as well as the underlying mechanisms remain poorly understood; especially the role of perceptual discrimination and its modulation by associative fear learning has received little attention so far. Experimental work with exteroceptive stimuli consistently points to effects of fear learning on perceptual discrimination acuity. In addition, clinical observations have revealed that in individuals with chronic pain perceptual discrimination is impaired, and that tactile discrimination training reduces pain. Based on these findings, we present a theoretical model of which the central tenet is that associative fear learning contributes to the development of chronic pain through impaired interoceptive and proprioceptive discrimination acuity.