Lack of startle blink potentiation to mutilation pictures irrespective of fearfulness

Previous research has shown that in healthy individuals blood-related stimuli elicit a distinctive autonomic response pattern and heightened processing as compared with other unpleasant and arousing visual stimuli. In addition, growing evidence suggests that information processing of disorder-related stimuli is also different in blood phobia as compared with other specific phobias. In the present study, the magnitude of the startle eyeblink reflex elicited during the viewing of mutilation, human attack, erotica and neutral pictures was recorded in 22 blood phobics and 25 healthy controls. Startle eyeblink responses were measured at 300, 1500, 3500 and 4500-ms time intervals after picture onset in order to assess the attentional/affective modulation and its temporal course. Reliable startle inhibition to erotic pictures and startle potentiation tohumanattack scenes were found relative to neutral pictures. However, while both groups rated mutilations as the most unpleasant and arousing content, no blink facilitation relative to neutral contents was found at either early or late probe times. Crucially, such effect occurred independently of fear levels, as no difference between phobics and controls was found in the size of the startle blinks elicited throughout the viewing of blood pictures.