Causal role of amygdala in coding evidence accumulation efficiency

To assess causal contributions of the amygdala, we applied Stereoelectroencephalography (SEEG)-guided neuromodulation in epilepsy patients, delivering high-frequency direct electrical stimulation (DES) to basal and lateral amygdala nuclei during alternating ON/OFF task blocks, with stimulation titrated below clinical thresholds. In a complementary protocol, focal radiofrequency ablation (RFA) provided permanent perturbations of amygdala nuclei following standard clinical evaluation. Neuromodulation state (DES ON/OFF, or pre/post RFA) was incorporated into hierarchical drift–diffusion modeling to quantify intervention-related changes in latent decision parameters, enabling direct comparison of subcortical perturbations.