The Effects of Task Load on Heart Rate and Heart Rate Variability

The relationship between task load and cardiovascular measures was investigated during single- and dual-task performance. The results showed significant reductions in Heart Rate Variability and the Blood pressure component of the Power Spectral Density function during task performance. No significant changes in HR were seen from baseline to task. However, differences in directional responding between subjects seemed to have obscured these effects. When direction of the HR response was disregarded and absolute magnitude of response was analyzed, significant differences from baseline to task were seen. There was no difference in physiological responding from single- to dual-task trials. Future research examining instantaneous changes in HRV as a direct function of decrements in performance is suggested.