Mental Load and the Measurement of Heart Rate Variability

Abstract
A number of studies concerning heart rate variability and mental load arereviewed It is concluded that in paced choice reaction tasks the number of reversal pointsin the cardiotachogram is the most sensitive measure of the load of the task.This measure was strongly correlated with respiration Spectral analysis of heart rate variability revealed the existence of a frequency component at about 0·10 Hz, a respiration frequency and sometimes a task frequency. In a number of tasks the respiration frequency increased, and the amplitude of energy in the lower frequencies decreased (i.e. there was a decrease in heart rate variability).