ABSTRACT
This chapter offers an hypothesis and supporting data about the pathophysiology of essential hypertension. The baroreceptor reinforcement instrumental learning (BR-IL) hypothesis attempts to bring together a number of behavioral and physiological principles. In BR-IL, as in the conventional model, aversiveness non-specifically increases the strength of various symptoms including hypertension; however, in BR-IL hypertension can independently reduce aversiveness through the baroreceptor mechanism. The dual roles of aversiveness as a cue and a reinforcer give the BR-IL model its unique capacity to explain psychosomatic symptom specificity. The BR-IL hypothesis offers an alternate interpretation: under differential reinforcement, environmental stimuli could eventually become the discriminative cues for hypertensive responses. Analysis of the extinction data suggested that baroreceptor stimulation attenuated the anxiety level as well as pain sensitivity. An additional correlational analysis revealed that the tendency to escape or avoid the stimulation was closely related to the degree of baroreceptor activation, as measured by phenylepherine induced heart rate slowing.
