Silvia Polver 1, Ermanno Quadrelli 1,2, Elisa Roberti 1,2, Hermann Bulf 1,2, Chiara Turati 1,2 1 Department of Psychology, University of Milano-Bicocca 2 NeuroMI, Milan Center for Neuroscience
Existing literature documented the recruitment of sensorimotor areas during the expression and observation of emotional faces. Although considerable efforts have been devoted to elucidating the neural underpinnings of the early development of emotion processing, little is known about the role of sensorimotor areas in the processing of facial expressions in infancy. The present study aims at investigating 7-month-olds’ sensorimotor activity and network configurations in response to static and dynamic facial expressions of emotions. Sensorimotor activity, as indexed by µ rhythm suppression, and network efficiency, as quantified by graph measures, were recorded through EEG while infants were presented with static (N= 19) or dynamic (N= 19) angry, happy, and neutral facial expressions. Results showed that happy faces elicited greater sensorimotor activity compared to angry faces during dynamic presentations, while no difference was found between emotional expressions in the static condition. Furthermore, happy expressions elicited greater right-lateralized activity during dynamic stimuli presentation, and dynamic emotional faces were characterized by a more efficient processing, as they elicited higher global efficiency and lower networks’ diameter compared to static faces. Overall, results suggest that dynamic emotional expressions modulate sensorimotor activity as early as 7 months of age and are more efficiently processed by functional brain networks. Finally, evidence regarding the presence of a right-lateralized activity for the processing of happy facial expressions supports the hypothesis of a prominent role of the right hemisphere in the processing of emotional information.