Central (hemodynamic) and peripheral (autonomic) synergy during persuasion within a shared decision-making process

This hyperscanning study explores the central (hemodynamic) and peripheral (autonomic) markers of persuasion within a shared decision-making process. Decision-making was examined through a task where two decision-makers assumed the role of Persuader (P-der) and Persuaded (P-ded), with the P-der aiming to increase group decision orientation in the P-ded. Data were collected from 14 dyads using functional near-infrared spectroscopy to measure prefrontal cortex (PFC) hemodynamic activity and collection and recording of autonomic indices including heart rate (HR) and HR variability (HRV). The analysis focused on two phases: Phase 1, where the P-der presented the scenario and enacted their persuasive strategy, and Phase 2, characterized by the P-ded’s response. The results revealed significant effects on the dissimilarity indices at the dyadic level. Compared with Phase 1, Phase 2 included higher oxygenated hemoglobin dissimilarity in the PFC, indicating greater inter-dyadic divergence during the P-ded’s response. HR dissimilarity increased when the P-ded spoke, suggesting disrupted synergy, while HRV dissimilarity was higher when the P-der spoke, potentially reflecting differences in stress regulation. These findings suggest that neurophysiological coherence varies based on persuasion phases within shared decision-making, with P-ded introducing greater dissonance in dyads synergy. Compared with single-subject approaches, dyadic analyses offer a more accurate understanding of the interpersonal nature of persuasion dynamics during decision-making.