The Effects of Operant Reinforcement Schedules on the Modification of Human Heart Rate

Thirty‐six male students were instructed to raise or lower their heart rates (HRs) and were provided with one of three different schedules of HR biofeedback. Within each direction of control condition, subjects were exposed to continuous beat‐by‐beat visual feedback, no feedback, or feedback presented according to a variable ratio (VR) schedule. During 4 training sessions VR subjects received feedback of a randomly selected 100%, 75%, 50%, or 25% of their heartbeats. All groups significantly altered their HRs in the instructed direction. For HR speeding, VR feedback produced significantly faster HRs than did continuous feedback while the VR schedule was in effect. No significant differences in HR slowing performance occurred among the three slowing groups. Resting initial HR levels did not significantly affect either speeding or slowing performance.