| Abstract: | The effects of heart rate feedback delay upon bidirectional heart rate control were determined by comparing four groups of 10 subjects who received either: a) immediate feedback, or b) feedback that was delayed by 1.4 sec, 5 sec, or 14 sec. All subjects received 3 sessions of training which included 3 within-session phases, i.e. 2 (pre and post-feedback) Instructional Control phases during which subjects were instructed to speed or slow heart rate without the aid of feedback, and a Feedback phase during which bidirectional heart rate control was assisted by analogue heart rate feedback. Heart rate, chin EMG, and respiration rate were recorded during all phases. The results indicated that the magnitude of heart rate increases and decreases was systematically influenced by differing amounts of feedback delay. For increasing and decreasing heart rate, the group receiving immediate feedback showed superior heart rate control in comparison to groups which received feedback that was delayed by 14 sec. The strongest effects of feedback delay were evident during Feedback and the final Instructional Control phase. Only the group receiving immediate feedback improved HR control during Feedback and post-feedback Instructional Control phases. These findings were discussed in terms of a motor skills learning model for learned HR control. It was concluded that while many of the same parameters influence HR and motoric behavior, the two responses should not be regarded as equivalent. |
