The role of gestures in human interaction: a new hyperscanning approach to investigate neurophysiological patterns in schizophrenic patients

Objectives:Schizophrenic patients show severe impairment in non-verbal communication. The loss of social and emotional perception affects planning and execution of gestures. Although there is evidence of neural basis that controls gestures planning and execution, actually it’s not clear how social and emotional gestures are processed, also considering clinical applications. Background and Aims:The aim of this study was to investigate the neural integration processes behind the planning and execution of specific categories of gestures with high emotional impact in a healthy sample, to furnish a normative sample to schizophrenia domain application. Materials and Methods:Central brain responses were analyzed using Near Infrared Spectroscopy (NIRS) in hyperscanning during social interaction in a dyad of subjects (encoder and decoder), consisting in planning and executing social, affective and informative gestures. Every gesture has positive or negative valence. The study focused on different activations between encoder and decoder for each gesture category. Results and Conclusions:Results showed that, during the gesture receiving, decoder had greater activation in the left-frontal hemisphere for social and affective gestures than encoder. Conversely, encoder showed a lateralization effect in the right-frontal hemisphere in executing informative gestures. No differences were found during gesture planning. This study provides theoretical knowledge on the neural integration for planning and execution of gestures in non-verbal communication. Results suggest a different brain activation between giving or receiving a gesture, especially with emotional and social value. Results are useful for guiding future studies on schizophrenic patients, suggesting to focus on patient’s brain activation during execution or receiving of gesture, helping to create new rehabilitative interventions.