Emotional specificity of startle potentiation during the early stages of picture viewing

Potentiation of the startle blink reflex shortly after picture onset has only been reported in a sample of high animal-fear participants during fear-evoking stimuli. The experiment tested the emotional specificity of startle reflex modification at early (300 ms) and late (2-5 s) stages of picture viewing in an unselected sample (n = 55). Participants viewed two negative picture categories, threat and disgust contents, in addition to neutral and positive pictures. Blink potentiation occurred for threat contents at both probe times, relative to neutral responses. Disgust contents only potentiated blinks relative to positive content responses. These results are inconsistent with a basic, prepulse interpretation of early startle modification and suggest that affective modification can be observed shortly after picture onset, depending on the specific emotional content of the Picture.