State anxiety and affective physiology: effects of sustained exposure to affective pictures

Effects of sustained exposure to emotional stimuli on affective reactions and their recovery were examined to determine whether increasing exposure to a specific emotional content (e.g., unpleasant) cumulatively affects physiological responses; and whether motivational activation persists following sustained exposure. Participants viewed pleasant, neutral, and unpleasant IAPS pictures, presented in blocks separated by an inter-block interval. With increasing exposure to unpleasant pictures, startle magnitude showed greater potentiation, and corrugator EMG activity increased. Both affective startle and corrugator modulation persisted following exposure to unpleasant pictures. The cumulative effects of sustained exposure to unpleasant pictures were enhanced for those reporting higher state anxiety, consistent with the hypothesis that sustained aversive exposure leads to increased defensive activation. These findings suggest sustained exposure to unpleasant pictures may induce a short-term mood state, and may be a useful paradigm to study individuals who vary in symptoms of anxiety.