Take-home message
iEEG analysis uncovers the neural mechanisms of human cooperation, highlighting the role of the amygdala and the temporoparietal junction in synchronizing during cooperation phases. This understanding can guide research on social behavior and inform interventions in neurological and psychological fields.
Background
Establishing and maintaining cooperation is essential for social animals to survive. While cooperation is known to depend on coordination and shared goals, the underlying behavioral and neural mechanisms are still not well understood. There is evidence showing that brain activity can synchronize between individuals in social interactions, as seen in mice, bats, and humans. However, it remains unclear how the brains of cooperators interact and coordinate at the neuronal level to support cooperative behavior.
Summary of the findings
Wang et al. developed a virtual cooperation game inspired by a “three-legged” race, where teammates had to connect and maintain their connection to reach the finish line. This setup allowed real-time tracking of cooperation behaviors. Using intracranial electroencephalographic (iEEG) recordings from 25 epilepsy patients, they analyzed brain activity in key regions involved in cooperation: the amygdala and the temporoparietal junction (TPJ). Their findings showed that changes in high-gamma activity (30–150 Hz) in these brain regions helped distinguish between the initiation and maintenance of cooperation. In particular, the TPJ was linked to teammate coordination and goal pursuit, while inter-brain synchronization in the amygdala and TPJ varied depending on the cooperation phase.
Novelty of the results in the field/ whether and how these results advance knowledge in the field
The research of Wang et al. enhances the understanding of human cooperation by identifying distinct neurocognitive profiles for different cooperation states. The study moves beyond simplistic models of cooperation, emphasizing a more dynamic and interactive approach. The innovative use of real-time behavioral tracking alongside intracranial recordings offers new possibilities for studying social behaviors in humans and animals.
However, due to the limitations of iEEG recordings, their study had restricted electrode coverage. Future research should investigate other brain areas, such as those linked to reward processing and motor functions, to provide a more comprehensive picture of cooperation. Additionally, since the study focused on a win–win scenario, further exploration is needed to understand behavior in social dilemmas. In addition, future studies should also examine how individuals balance personal interests with collective goals, how free-riding behavior emerges, and the differences between cooperative and competitive interactions. Refining the experimental design by introducing dynamic goals or varying task difficulty could help capture more complex cooperation dynamics.
By Maria Teresa Gallo, Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, University of Milan.
Link and doi of the publication:
doi: https://doi.org/10.1038/ s41593-024-01824-y