Shyness and the first 100 ms of emotional face processing.

Although shyness is presumed to be related to an increased sensitivity to detect motivationally salient social stimuli, we know little of how shyness affects the early perception of facial emotions. We demonstrate here that individual differences in normative shyness were related to brain responses to some emotional faces as early as the P1 electrocortical component, 80-130 ms after stimulus onset. High-shy individuals showed reduced P1 amplitude for fearful faces compared to neutral faces. Low-shy individuals processed happy faces faster than other emotions and showed increased P1 amplitudes for happy faces over neutral faces. Regardless of shyness level, participants showed increased amplitudes in the N170 component (130-200 ms) for all emotions over neutral conditions, particularly for the emotion of fear. This study presents the first evidence that shyness is related to early electrocortical responses to the processing of fearful faces, consistent with a fast-path amygdala sensitivity model.