(December 29, 2015) Abstract
Efficient detection and reaction to negative signals in the
environment is essential for survival. In social situations, these signals are
often ambiguous and can imply different levels of threat for the observer,
thereby making their recognition susceptible to contextual cues – such as gaze
direction when judging facial displays of emotion. However, the mechanisms
underlying such contextual effects remain poorly understood. By computational
modeling of human behavior and electrical brain activity, we demonstrate that
gaze direction enhances the perceptual sensitivity to threat-signaling emotions
– anger paired with direct gaze, and fear paired with averted gaze. This effect
arises simultaneously in ventral face-selective and dorsal motor cortices at
200 ms following face presentation, dissociates across individuals as a
function of anxiety, and does not reflect increased attention to
threat-signaling emotions. These findings reveal that threat tunes neural
processing in fast, selective, yet attention-independent fashion in sensory and
motor systems, for different adaptive purposes.