关键词: 羞怯, 面孔识别, N170, ERP

Abstract: Shyness refers to individual’s behavioral inhibition in social situations and a fear for negative evaluation in social situations which is closely associated with social cognition. Face recognition is an important type of social cognitive abilities in social life. In recent years, the majority of the neurophysiologic studies on shyness have focused on the effect of expressional valence and facial new-old effects upon face processing of shy individuals. It has been found that shyness predicted significantly smaller N400 amplitudes in response to anger and to a neutral expression (Marco, et al., 2005). In addition, it has also been reported that there existed greater functional MRI signal response within the amygdala to novel than to familiar faces among healthy young adults who were originally categorized as behaviorally inhibited and temperamentally shy in early childhood (Schwartz, Wright, Shin, Kagan, & Rauch, 2003). Shy adults exhibited greater bilateral amygdala activation during the presentation of strange faces and greater left amygdala activation during personally familiar faces than their bold counterparts (Beaton, et al., 2008). Although these results revealed that shy individuals and nonshy individuals had cognitive and neural differences in facial expression recognition and old-new face recognition, whether there exist cognitive and neural differences in the basic face recognition ability (e.g., face and object recognition) between shy and nonshy individuals remains an issue to be examined.
This study investigated into N170 component via the face-object recognition tasks in order to explore the neurophysiologic differences in the early face processing between shy and nonshy undergraduates. The subjects were 17 shy undergraduates and 17 nonshy undergraduates.
The major findings of the present study were: (1) the level of shyness interacted significantly with the types of stimuli, with the N170 amplitude of shy undergraduates being greater than that of nonshy undergraduates in face recognition, but this difference did not exist in object recognition. (2) There existed a significant effect of types of stimuli, such that the N170 amplitude elicited by face images was higher than that elicited by object images, and the N170 latency elicited by face images was shorter than by object images. (3) There was significant interaction between the hemispheres of the brain and the types of stimuli. Compared with left hemisphere, the N170 amplitude of right hemisphere was greater in face recognition, but the difference wasn’t significant between left and right hemisphere in object recognition.
The findings of this study suggest that nonshy undergraduates have processing dominance in facial configuration, and the N170 amplitude of the nonshy undergraduates is greater than that of the shy undergraduates in face recognition. N170 is the special component in face recognition. The right hemisphere manifests processing dominance in N170 in face processing.

Key words: shyness, face recognition, N170, ERP