Prediction of physiological arousability: a validation of the Arousal Predisposition Scale

The Arousal Predisposition Scale (APS) is a brief (12-item) scale, that purportedly measures arousability, and has already been shown to predict task related arousal changes measured via self-report indexes. To determine if APS scores could predict individual differences in physiological measures of arousal, it was administered to 239 subjects. From this group, 9 highly arousable subjects and 9 low arousable subjects (based on APS scores) were selected. Each subject was repeatedly exposed to an arousing stimulus consisting of a 105 dB white noise. Electrodermal activity and the electromyographic response were used as indexes of change in autonomic and affective arousal. Subjects who scored highly arousable on the APS showed a greater change in electrodermal and electromyographic response than subjects judged low on arousability. This appears to validate the usefulness of the APS as a measure of individual differences in predisposition toward arousability.