Electrophysiological mechanism of executive function deficits in obsessive-compulsive disorder: An EEG microstates study.

Background: Executive dysfunction is a common feature in patients with obsessive-compulsive disorder (OCD), yet its underlying electrophysiological mechanisms remain incompletely understood. This study aimed to investigate the characteristics of Electroencephalography (EEG) microstates in patients with OCD while they performed executive-function tasks.

Methods: Eighty-five patients with OCD and 86 healthy controls (HC) completed the Task-Switching Paradigm, Stop-Signal Task, and N-back task, which assess shifting, inhibition, and working memory updating functions, respectively. EEG data were recorded and analyzed utilizing microstate and standardized low-resolution brain electromagnetic tomography (sLORETA) methods.

Results: Patients with OCD exhibited impairments across all three executive function tasks. EEG microstate analysis revealed abnormal neural dynamics in the OCD group. Specifically, OCD patients showed a shorter duration of a frontal-parietal executive microstate and prolonged dominance of a precuneus-related microstate, reflecting altered large-scale network activity. Source localization further indicated decreased activation in parietal lobes and increased precuneus activation in OCD during shifting, overactivation of occipital-parietal regions but reduced frontal engagement during response inhibition, and reduced frontal-parietal activation during working memory updating.

Conclusion: OCD is associated with broad disruptions in executive functions, accompanied by aberrant spatiotemporal brain dynamics. Our findings indicate that patients' difficulties in shifting, inhibition, and updating are tightly linked to abnormal EEG microstate patterns and altered regional brain activations, highlighting the utility of high-temporal-resolution EEG measures in probing the neural mechanisms of OCD.