Learning to control heart rate: binary vs analogue feedback.

Twenty-two male volunteers participated in an experiment designed to test the efficiency of two procedures, one emphasizing analogue and the other binary feedback, in training human subjects (Ss) to change their heart rate. Ss were seen for 7 separate sessions, which included 2 training sessions in speeding heart rate and 2 devoted to slowing. Both heart rate and respiration cycle length were recorded. The timing of the experiment, presentation of instructions, feedback, data acquisition, and primary data reduction were all accomplished in real-time by a computer. The feedback mediated acquisition of directional changes in heart rate was demonstrated, and these changes were sustained on instruction with feedback removed. No differences between the binary and analogue procedures were noted for slowing. However, the analogue display prompted significantly greater instructed acceleration than the binary method. An important distinction was made between organ feedback (heart activity) and task performance feedback (relative success or failure). It was noted that the acquisition of heart rate speeding and slowing appear to involve different psychophysiological mechanisms.