Contextual effects of angry vocal expressions on the encoding and recognition of emotional faces: An event-related potential (ERP) study

It has been shown that stimulus memory (e.g., encoding and recognition) is influenced by emotion. In terms of face memory, event-related potential (ERP) studies have shown that the encoding of emotional faces is influenced by the emotion of concomitant context, when contextual stimuli were input from a visual modality. Behavioral studies also investigated the effect of contextual emotion on subsequent recognition of neutral faces. However, there might be no studies ever investigating the context effect on face encoding and recognition, when contextual stimuli were input from other sensory modalities (e.g., an auditory modality). Additionally, it may be unknown about the neural mechanisms underlying context effects on recognition of emotional faces. Therefore, the present study aimed to use vocal expressions as contexts to investigate whether contextual emotion influences ERP responses during face encoding and recognition. To this end, participants in the present study were asked to memorize angry and neutral faces. The faces were presented concomitant with either angry or neutral vocal expressions. Subsequently, participants were asked to perform an old/new recognition task, in which only faces were presented. In the encoding phase, ERP results showed that compared to neutral vocal expression, angry vocal expressions led to smaller P1 and N170 responses to both angry and neutral faces. For angry faces, however, late positive potential (LPP) responses were increased in the angry voice condition. In the later recognition phase, N170 responses were larger for neutral-encoded faces that had been presented with angry compared to neutral vocal expressions. Preceding angry vocal expression increased FN400 and LPP responses to both neutral-encoded and angry-encoded faces, when the faces showed the encoded expression. Therefore, the present study indicates that contextual emotion with regard to vocal expression influences neural responses during face encoding and subsequent recognition.