Postauricular and eyeblink startle responses to facial expressions.

Emotional facial expressions have affective significance. Smiles, for example, are perceived as positive and responded to with increased happiness, whereas angry expressions are perceived as negative and threatening. Yet, these perceptions are modulated in part by facial morphological cues related to the sex of the expresser. The present research assessed both eyeblink startle and the postauricular reflex during happy and angry expressions by men and women. For this 14 male and 16 female undergraduates saw happy, neutral, and angry facial expressions as well as positive and negative pictures. The postauricular reflex was potentiated during happy expressions and inhibited during anger expressions; however, as expected, this pattern was more clearly found for female expressers. Conversely, the expected pattern of eyeblink startle potentiation during angry faces and inhibition during happy faces was found only for male expressers.