Interaction On The Amygdala Activation Between Personal Familiarity And Fear Expression In Face Perception: An FMRI Study

The human amygdale take part in processing both the basic motivational properties of information, such as basic emotion, food, sex, as well as social prosperities of information, such as social emotion, gaze direction and familiarity. Though there were a large number of studies concerning either of them, few studies explored the potential interaction on amygdala between them. We took two factors of fear facial expression and personal familiarity to constitute four type stimulus: Familiar Fear face (FF), Familiar Neutral face (FN), Unfamiliar Fear face (UF) and Unfamiliar Neutral face (UN). Through instructing subjects to passively view face images, we used functional magnetic resonance imaging (fMRI) to investigate the amygdale activation to stimulus. Our results indicated that fear expression and personal familiarity interacted with each other on amygdale activation and when subjects viewed unfamiliar fear faces, the amygdale were most activated. We further suggested that unfamiliarity factor might tend to activate amygdale with priority. At the same time, the result that familiar fear faces elicited weaker response in amygdale than unfamiliar fear faces questioned relevance detection model of amygdala function.