Effects of Binary and Proportional Feedback on Bidirectional Control of Heart Rate

Six male and 6 female volunteers formed three groups of 4 subjects in a study on the efficacy of different forms of visual feedback on control of heart rate (HR). One group received proportional feedback from a meter plus a binary success signal, one group received only proportional feedback, and one group received only the binary signal. Subjects received 6 acquisition sessions and 4 extinction sessions. For HR increase, groups receiving proportional feedback showed mean control over the last 2 acquisition sessions of +10 bpm, whereas the group receiving only binary feedback showed control of +4 bpm. For HR decrease, both groups receiving proportional feedback showed mean control over the last 2 acquisition sessions of ‐4 bpm, whereas the group receiving only binary feedback showed negligible control. During extinction there was no immediate reduction hi control of either HR increase or HR decrease but both declined over extinction sessions. Results indicate that proportional feedback is clearly superior to binary feedback, and that the addition of a binary signal to proportional feedback does not reliably enhance control. Results are consistent with an operant conditioning interpretation of feedback control.