Neural correlates of face evaluation: emotional expressions and social traits

Face processing is a crucial skill for human interaction. Accordingly, it is supported by a widely distributed fronto-temporo-occipital neural circuit (Haxby et al., 2000). The present work investigates the neural correlates of face expression processing by means of different neuroimaging and electrophysiological techniques. Using fMRI I investigated amygdala responses to basic emotions and activations in face-selective regions in response to social cues detected in faces (Study 1 and Study 2). These studies showed that the amygdala is highly responsive to fear expressions but has also a critical role in appraising socially relevant stimuli and together with the posterior face-selective regions it is sensitive to face distinctiveness as well as social meaning of face features. In Study 3 I demonstrated by means of TMS that the medial prefrontal cortex (mPFC) contains different neural representations for angry and happy expressions linked to lexical knowledge of emotions. Finally, the combined TMS-EEG experiment reported in Study 4 revealed interconnections between activity in the core and the extended system of face processing, and the interactions resulted to be modulated by the type of behavioural task. Taken together the present results help to clarify the role of different regions as part of the face perception system and suggest that the coupling between cortical areas and the coordinated activity of different regions in the distributed network are crucial to recognize the multiplicity of information that faces convey.