SENSITIVITIES OF HR AND T-WAVE AMPLITUDE FOR DETECTING COGNITIVE AND ANTICIPATORY STRESS

Five groups of subjects were used to investigate the sensitivities of HR and T-wave amplitude for detecting stress associated with the performance of a difficult mathematical task and the anticipation of a noxious, noise stimulus following the task. During performance on the mathematical task, there were no group differences but HR showed a significant biphasic, acceleration-deceleration response while T-wave was significantly attenuated and remained attenuated for the entire duration of the task. During the anticipation period prior to the occurrence of the noxious stimulus, HR showed significant differentiation between the 5 groups in terms of the degree of anticipatory HR deceleration that developed while, on the other hand, T-wave amplitude merely returned from the attenuated level during task performance toward baseline levels at the same rate for all groups. It was concluded that T-wave amplitude was a more sensitive index of cognitive stress associated with the performance of a mathematical task while HR was a more sensitive index of anticipatory stress associated with the anticipation of a noxious event. In addition, it was concluded that most HR changes were parasympathetically mediated regardless of direction. © 1979.