Neural correlates of social influence in persuasion process: a hyperscanning EEG study on negotiation.

Group decision-making requires integrating different perspectives through persuasion, which involves unidirectional social influence, and negotiation, which is a reciprocal interaction based on cooperation and competition. While neuroscientific research has focused on identifying brain activations associated with these processes and their influencing factors, the impact of a prior persuasive dynamic on a subsequent negotiation task remains unexplored. This study examines whether engaging in a persuasive task, in which one individual has a role of social influence, affects neural activity during a subsequent negotiation. Using a hyperscanning paradigm with electroencephalography (EEG), frequency bands (delta, theta, alpha, beta and gamma) were analyzed in frontal, temporo-central and parieto-occipital regions in a sample of 26 participants. Results highlight distinct brain activation patterns between former persuaders and former receivers, with increased left-hemisphere delta activity and frontal theta and alpha activation in persuaders, while former receivers exhibited higher beta activity in the right parieto-occipital regions in the final stage of negotiation and higher gamma activity in right-lateralized regions. Overall, the study suggests that prior persuasive interactions shape subsequent negotiation at a neural level, influencing emotional, cognitive, and strategic engagement, with potential implications for understanding social dynamics in group interactions.