Predicting autonomic reactivity to public speaking: don't get fixed on self-report data!

The study focused on the prediction of autonomic reactivity to public speaking by using self-report and objective data (other-ratings and behavioral data) of task-induced nervousness and task engagement. Forty-one individuals participated in the study. Heart rate and electrodermal activity were recorded during baseline and speech delivery. Stepwise multiple regression analyses indicated that self-report data of task engagement and nervousness largely failed in predicting psychophysiological reactivity to the speech task. After controlling for baseline values, demographic variables, and self-report data objective variables, however, were strong predictors of autonomic reactivity. Heart rate reactivity was significantly associated with gaze-duration towards the camera, indicating task engagement/involvement. Electrodermal activity was significantly related to other-rated nervousness/unstableness. Researchers are encouraged to record additionally objective variables when focusing on the prediction of psychophysiological reactivity.