FACE FAMILIARITY DISPLAYS GREATER MODULATORY EFFECTS FOR NEUTRAL THAN FOR HAPPY OR ANGRY IDENTITIES - FINDINGS FROM A MIXED BEHAVIOURAL-ELECTROPHYSIOLOGICAL STUDY

Successful facial emotion processing relies on a wide range of neuroanatomical structures that integrate information received from visual stimuli. Although the current literature describes the existence of two individual neural pathways (i.e., dorsal and ventral) involved in face processing, their level of independence is not currently well understood. To test the extent of this independence, we conducted an electrophysiological investigation of the effects of antithetic emotions (Happy, Angry, and Neutral) on processes of encoding and consolidation of morphed facial stimuli (Low, Medium, and High morphing levels). A mixed behavioural-electrophysiological approach was used to assess the time course and spatial scalp distribution of short-term face familiarity effects, and to observe the modulatory influence of emotional expressions on such processing. Analyses of our EEG data indicated that significant cortical differences between Neutral and Happy/Angry expressions, and between low and greater levels of morphing were present across the 285-567 ms processing time window. These results were also complemented by our behavioural data findings, where Neutral expressions correspondingly displayed better performance (i.e., faster reaction times and greater similarity ratings) than Happy/Angry expressions, and the same pattern was also observed for Low versus Medium/High morphing levels. Finally, the extent of neural interconnectivity between the cortical brain regions involved in this processing was identified using source localisation, and this will be discussed in accordance with the previously published neurofunctional models to highlight the involvement of each identified brain region in the different stages of face processing.