Neural mechanisms of cognitive dysfunction in depression: dual-task event-related potentials and task-phase-dependent EEG functional connectivity

To investigate the neurophysiological features underlying depression-related cognitive dysfunction via dual-task event-related potential (ERP) and task-phase-dependent electroencephalography (EEG) functional connectivity analysis. Thirty patients with depression (DP group) and 30 matched healthy controls (HC group) underwent EEG recordings across pre-task resting state, face perception task (indexed by N170), face mismatch conflict monitoring task (indexed by N270), and post-task resting state. Functional connectivity was quantified using imaginary coherence (iCoh), with between-group comparisons corrected by Benjamini–Hochberg false discovery rate (FDR). Correlation analyses between electrophysiological metrics and clinical variables were performed in the DP group. The DP group exhibited prolonged latency and decreased amplitude of N170, prolonged latency and increased amplitude of N270, as well as task-phase-dependent multi-frequency brain network imbalances. In the DP group, longer N170 and N270 latencies were associated with more severe depressive symptoms, whereas task-phase-dependent functional connectivity abnormalities showed no significant associations with clinical variables. Depression was associated with electrophysiological abnormalities in emotional processing and conflict monitoring, as well as task-phase-dependent brain network imbalances, providing exploratory neurophysiological evidence related to depression-associated cognitive dysfunction. Not applicable.