The influence of facial expression absence on the recognition of different emotions: Evidence from behavioral and event-related potentials studies

Abstract

Facial expressions convey rich information in emotional communication but are not always accessible in all social contexts. In such situations, bodily expressions serve as critical cues for accurate emotion recognition. The reliance on facial expressions differs between basic and complex emotions, reflecting distinct underlying processing mechanisms. This study investigates how the absence of facial expressions influences the recognition of these two types of emotions. Participants viewed full-body images depicting basic and complex emotions, either with both facial and bodily expressions visible, or with the facial region occluded to remove facial information. They judged the emotional congruence between the images and preceding emotional words. The ERP study included only female participants, considering potential gender differences in emotion recognition mechanisms. Behavioral results revealed that the absence of facial expressions significantly reduced the accuracy and speed of emotion recognition, with a greater impact on basic emotions than on complex ones. ERP data further demonstrated distinct processing patterns: larger N170 amplitudes were observed for congruent word-image pairs, and stronger N400 responses occurred when facial expressions were present, indicating enhanced early and mid-stage integration of emotional information. LPP amplitudes were generally higher in congruent conditions, and were further enhanced for complex emotions when faces were present, and for basic emotions when faces were absent. These findings highlight the essential role of facial expressions in facilitating basic emotion recognition, while complex emotions rely more heavily on bodily cues for effective processing.

Keywords: Basic emotion; Complex emotion; ERP; Emotion recognition; Facial expression.