Alterations of the human electroencephalogram induced by stressful verbal activity

Abstract

Certain auto- and cross-spectral components of the EEG appear to be characteristic of responses to verbal stimuli. Employing a discriminant-analysis procedure applied to spectral parameters, it proved possible to separate subjectively stressful from non-stressful verbal stimuli, and to determine distinctive EEG responses to verbal stimuli of similar stress value differing only in semantic content. The EEG components characteristic of these response states were consistent over small populations, and the criteria developed for their identification proved valid over several different subjects without requiring individual calibration. Other, individual-specific characteristics of the EEG were observed consistently to parallel the cyclical occurrence of several constituent epochs in a twenty-item question-answer sequence.