Effects of instructions and contingency of reinforcement on the operant conditioning of human phasic heart rate change.

Abstract

ABSTRACTThe aim of these studies was to determine the effects of instructions and reinforcement contingency on phasic heart rate (HR) change. In Exp. I, 36 human subjects were given 20 conditioning trials with a muscletensing task which produced a phasic HR acceleration. The experimental manipulation produced an elevated baseline and allowed for the observation of instructed HR change during exercise. A 2 × 2 between subject design varied instructions (to increase or decrease the phasic tension‐induced HR acceleration) and contingency (whether the verbal reinforcement was contingent on or unrelated to HR change) as factors. There was a significant instructional effect at the end of conditioning, with increase subjects producing more HR acceleration and decrease subjects less acceleration relative to pretrials. The instructional effect developed over trials and decrease subjects significantly improved with practice. There was no difference between contingent and non‐contingent groups in either of the two conditions in ability to change HR in the instructed direction. This study shows the usefulness of the elevated baseline technique for cardiac research. A second experiment demonstrated that, in subjects not instructed to attempt HR change, the phasic HR response did not change in magnitude over conditioning. The results of these studies indicate that subjects are able to control phasic HR during physical‐stress induced tension but biofeedback is not relevant for the production of such HR changes.