Abstract
Highlights Frontal ERPs reflect the distinct neural responses to partners’ behavioral cues during negotiation. • ERP-based causal modeling reveals directional neural interactions between partners in social exchange. • Prediction model incorporating interbrain causal links improves accuracy compared to single-brain models during asymmetric social interaction. • An ERP-based causal model offers a novel framework for understanding complex social behaviors. Uncovering the interbrain neural mechanisms underlying interpersonal negotiation offers insight into social decision-making dynamics in resource allocation. In this study, we used EEG hyperscanning alongside an iterated ultimatum game to investigate interbrain coupling and dyadic exchange behavior during negotiation. Frontal cortex event-related potentials (ERPs) revealed the distinct neural responses driven by partners’ behavioral cues: the proposer’s N200 differed significantly for fair versus unfair offers, and the responder’s feedback-related negativity (FRN) showed a trend toward significance for the same contrast, while the proposer’s N500 varied between acceptance and rejection feedback. Our analysis introduced a novel causal model based on directional phase transfer entropy (dPTE) and time-varying ERP amplitudes, illustrating directed neural processes driven by social exchange, where the proposer’s brain activity initially exerts a causal impact on the responder’s, whose feedback in turn influences the proposer, creating a closed-loop interaction that drives adaptive negotiation strategies. Additionally, our prediction model with autoregression with exogenous input, which incorporated these causal links between brains, demonstrated higher accuracy than single-brain or reverse causal models, underscoring the significance of dynamic interbrain coupling in interpersonal coordination. This causal model provides a mechanistic explanation of how proposer-responder pairs perceive and adapt to each other’s decisions, facilitating shared attention and behavioral coordination in reciprocal, asymmetric negotiations. These findings offer a novel theoretical framework for studying complex social behaviors through interbrain dynamics and may inspire future applications in enhancing cooperative decision-making processes. Keywords Interbrain couplings Ultimatum game Interpersonal negotiations Event-related potential EEG hyperscanning
Authors
Li, Y., Sarah, G., Chen, C., Jiang, L., Chen, B., Li, R., Liang, Z., Yu, J., Dong, D., Wan, F., Becker, B., Yao, D., Li, F., Zhang, Xu, D. &., & P.
https://doi.org/10.1016/j.neuroimage.2025.121541