Brain Mapping of Behavior Contagion Based on Visibility Graph Analysis of ERP Signals

Behavior contagion in social decision-making refers to the alignment of an individual's behavior and decisions with those of others in social interactions. Despite previous studies in the field, it remains necessary to understand how brain activities are spatiotemporally organized during contagion. Since brain activities include both positive and negative fluctuations, monitoring these occurrences in a polar space using a visibility graph (VG) can aid in a better understanding of this phenomenon.

We subjected a healthy group to a psycho-economic task while their EEG was simultaneously recorded. The participants' performances were compared before and after observation of others' preferences in a dictator game task. Subsequently, two groups were differentiated based on their behavior contagion rate. Then, the VGs of event-related potentials (ERPs) in both contagion and non-contagion groups were compared before and after observation.

Our results indicated that the VG features differentially change in various EEG channels. For instance, changes in clustering coefficient, modularity, and efficiency of VGs suggested that the number of ERP components varies after contagion, specifically at the frontal, frontocentral, centroparietal, and parietal regions.

This result may raise questions about the ERP analysis of contagion, particularly when using the same number and length of components (e.g. P300) for comparing ERPs before and after contagion.