Inhibited and disinhibited temperament and autonomic stress reactivity.

We examined the relationship of temperament dimensions serving as markers for Gray's behavioral activation system (BAS) and behavioral inhibition system (BIS) with autonomic stress reactivity in 35 middle-aged men. Temperament was measured using the Strelau Temperament Inventory--Revised. Skin conductance responses and inter-beat interval were measured during administration of the Rorschach test. The results showed that temperamental activation was positively related to the task-level of and task-induced change in respiratory sinus arrhythmia (RSA) amplitude, but unrelated to heart rate (HR) reactivity. Temperamental inhibition was negatively associated with the task-level of electrodermal activity and task-induced change in RSA amplitude, and positively associated with HR reactivity. The findings are in part contrary to the hypotheses presented in the literature. They also suggest that the temperamental inhibition-HR reactivity relationship is mediated by the parasympathetic nervous system.