Auricular transcutaneous vagus nerve stimulation stabilizes event segmentation through modulation of working memory representations

Across behavioral and neural measures, atVNS stabilized ongoing event representation and restricted the updating of the current event working model, consistent with a GABAergic modulation of event segmentation. These findings extend prior work linking atVNS to working memory gating and demonstrate its impact on an ecologically relevant cognitive process-event segmentation. Significance Statement This study tests whether 2 neuromodulators-norepinephrine (NE) and GABA-causally change how people divide continuous experience into meaningful events-a process called event segmentation. We used auricular vagus nerve stimulation (atVNS) to nudge these systems and compared active stimulation with a sham control. Compared to sham, active atVNS reduced the probability of setting event boundaries. In parallel, the brain activity patterns before the moments of segmenting were less distinct from the no-boundary period than in the sham condition, with lower activity in prefrontal regions. Together, these converging behavioral and neural findings indicate that atVNS stabilizes ongoing event representations and restricts the updating of the current event working model, a pattern that more parsimoniously supports a GABAergic inhibitory gating account over an NE arousal account of event segmentation.