Large Magnitude Heart Rate Changes in Subjects Instructed to Change Their Heart Rates and Given Exteroceptive Feedback

Four subjects who were given exteroceptive, auditory and visual feedback, and were asked to raise and to lower their heart rate on signal, were able to produce large magnitude changes in both directions. The fact that some of these changes occurred immediately suggests that feedback may not be as important as some authors have suggested. Respiratory changes and changes in muscle tension did not appear to be mediators.