Twenty-four undergraduate male volunteers participated in an experiment designed to assess the effect of voluntary control of heart rate deceleration on skin conductance level. One group of subjects received heart rate feedback training and a second group performed a tracking task. Because heart-rate feedback was presented via a visual display, the tracking task group was included to control for display monitoring influences on heart rate. Results demonstrated feed-back mediated acquisition of learned control of heart rate slowing. More importantly, the heart-rate slowing performance was accompanied by increases in skin conductance level. This 'fractionation' of physiological responding suggests the presence of a physiological response pattern which may counter initial attempts to produce greater magnitude slowing effects.