Fear-potentiated startle: relationship to the level of state/trait anxiety in healthy subjects.

The startle reflex is potentiated during experimentally induced anxiety (fear-potentiated startle). It is also increased in various anxiety disorders. The present study investigated the relationship between individual differences in fear and anxiety, and startle modulation. The eyeblink component of the acoustic startle reflex was measured in a paradigm involving the anticipation of electric shocks in 22 healthy men who were volunteers. Each subject's fear of shock was assessed with the state portion of the State-Trait Anxiety Inventory (STAI; Spielberger 1983). Fear-potentiated startle, but not baseline startle, differed in the low and high fear subjects. The magnitude of fear-potentiated startle was larger in the high-fear group as compared to the low-fear group. The time-course of startle modulation suggested a longer duration of anticipatory anxiety in the high-fear group. Trait anxiety, which was assessed with the trait portion of the STAI, did not relate to individual differences in either baseline or fear-potentiated startle.