Impact of motivational salience on affect modulated startle at early and late probe times.

This study systematically manipulated both picture content and noise probe time in order to evaluate the effects of motivational salience (as distinguished from affective valence) on both early and late modulation of the startle response. Specifically, modulation was compared for erotic versus action/adventure scenes, and for direct threat versus victim scenes, at early (300 and 800 ms) and late (3500 ms) probe times -- all relative to neutral. Blink inhibition was observed at all probe times during presentation of erotic pictures, and blink potentiation was evident at all times during presentation of direct threat pictures. Patterns of blink modulation were less consistent for action and victim picture contents. These findings are consistent with the hypothesis that under conditions of high motivational salience, affective startle modulation indexes the activation of appetitive-approach and defensive motivational states, even at early stages of picture processing.