Up close and emotional: Electrophysiological dynamics of approaching angry faces

Recent evidence suggests that looming emotional faces are processed rapidly by the neural system, and that this apparent approach further interacts with emotion, causing an enhanced neural response for angry expressions. However, previous research has not demonstrated unequivocally if these effects are due to low-level visual features, or if they are indeed due to the emotional content of the stimuli. To address this question, the current study presented upright and inverted angry and neutral faces, which either expanded or contracted in size on a constant depth-cued background, such that they appeared to approach or retreat from the viewer. EEG/ERP measures were used to identify the time course of brain activity for these stimuli. The results showed that when faces were upright, both the P1 and N170 were enhanced for angry expressions, with the P1 being further increased with looming angry faces. The inversion of the faces caused an increase in both the P1 and N170 amplitudes, but no modulation was found for emotions. These findings show an early modulation of brain activity for upright looming angry faces and rule out the influence of low-level visual features as a contributing factor.