# Neurophysiological correlates of interpersonal discrepancy and social adjustment in an interactive decision-making task in dyads

## TL;DR

This study explores how people adjust their behavior during social interactions and identifies brain activity linked to spontaneous cooperation and convergence in decision-making.

## Contribution

The study introduces a novel experimental paradigm to investigate spontaneous social convergence and its neurophysiological correlates in dyadic interactions.

## Key findings

- Participants who interacted in the pre-activation phase showed higher spontaneous convergence in decisions.
- ERP and time-frequency analyses revealed theta, alpha, and beta brain activity linked to social convergence and discrepancy processing.
- The paradigm effectively captures neurophysiological correlates of social behavioral adaptation in experimental settings.

## Abstract

The pursuit of convergence and the social behavioral adjustment of conformity are fundamental cooperative behaviors that help people adjust their mental frameworks to reach a common goal. However, while social psychology has extensively studied conformity by its influence context, there is still plenty to investigate about the neural cognitive mechanisms involved in this behavior.

We proposed a paradigm with two phases, a pre-activation phase to enhance cooperative tendencies and, later, a social decision-making phase in which dyads had to make a perceptual estimation in three consecutive trials and could converge in their decisions without an explicit request or reward to do so. In Study 1, 80 participants were divided in two conditions. In one condition participants did the pre-activation phase alone, while in the other condition the two participants did it with their partners and could interact freely. In Study 2, we registered the electroencephalographical (EEG) activity of 36 participants in the social decision-making phase.

Study 1 showed behavioral evidence of higher spontaneous convergence in participants who interacted in the pre-activation phase. Event related Potentials (ERP) recorded in Study 2 revealed signal differences in response divergence in different time intervals. Time-frequency analysis showed theta, alpha, and beta evidence related to cognitive control, attention, and reward processing associated with social convergence.

Current results support the spontaneous convergence of behavior in dyads, with increased behavioral adjustment in those participants who have previously cooperated. In addition, neurophysiological components were associated with discrepancy levels between participants, and supported the validity of the experimental paradigm to study spontaneous social behavioral adaptation in experimental settings.