Intracranial EEG links amygdala representational alignment to mutual cooperation in Prisoner's Dilemma

{"Researchers recorded directly from amygdala electrodes while pairs independently chose cooperate or defect across repeated rounds. They quantified inter-brain similarity first as signal correlation, then advanced to representational alignment by comparing trial-wise neural patterns against shared cognitive content such as prior interaction history and simulated partner intent. Mutual cooperation trials showed elevated alignment relative to mixed or mutual-defect trials.","This content-based mechanism extends earlier fMRI hyperscanning work that reported only coarse inter-subject correlations without identifying the information represented. The epilepsy-patient sample, though clinically selected, supplies millisecond-resolution data unavailable in healthy volunteers and isolates the amygdala's contribution to social prospective simulation during sustained cooperation.","The design cannot establish causality or generalize beyond medial temporal structures; next studies must test whether amygdala alignment predicts cooperation rates prospectively and whether analogous patterns appear in prefrontal or temporoparietal regions using non-invasive methods in larger community samples.","If replicated, the finding reframes inter-brain synchrony as a consequence of jointly represented task states rather than an independent driver, guiding interventions that target shared cognitive representations to enhance cooperation."}