The Interaction of Instruction Components with Cybernetic Feedback Effects in the Voluntary Control of Human Heart Rate

Two groups of 20 subjects were presented with either contingent or yoked feedback for heart rate increase and decrease. Subjects were instructed to either attend to their heart (attention instructions) or to increase or decrease their physiological activity (direction instructions). Half of each contingent group made the signal go on for HR increase (tone‐on feedback) and off for decrease. The other half made the signal go off for increase (tone‐off feedback) and on for decrease. It was found that direction instructions led to significantly better HR control than attention instructions for yoked but not for true feedback. For true feedback, tone‐on led to HR increase, while tone‐off interfered, leading to overall HR decrease. This did not occur for yoked feedback, suggesting the importance of contingent feedback in this effect. An additional finding of this study was that subjects' self‐ratings of control were identical for true and yoked subjects, and did not correspond to their actual degree of control, suggesting that the feedback effects were mediated unconsciously. It was concluded that the direction component of HR instructions may obscure true cybernetic feedback effects which emerge through the manipulation of contingency and positive/negative feedback loops.