Event-related EEG microstate complexity reveals specific brain network connectivity during aesthetic perception in depression

<p>Visual aesthetic experience recruits distributed brain networks encompassing perceptual, emotional, and cognitive processes. Individuals with major depressive disorder (MDD) often exhibit altered aesthetic preferences, typically biased toward negative stimuli, yet the underlying neural dynamics remain poorly understood. In this study, 25 patients with MDD and 27 healthy controls (HCs) were recruited and performed image-based aesthetic processing tasks while the EEG signals were collected using a 32-channel system. EEG microstate was obtained by iterative clustering and the duration, occurrence, coverage, Lempel-Ziv complexity, and functional connectivity were calculated and analyzed. Significant alterations in both the spatial and temporal characteristics of EEG microstates were observed in the MDD group. Specifically, individuals with MDD showed increased occurrence and coverage of microstates associated with posterior visual processing, and reduced coverage and duration of those linked to right prefrontal executive control networks. These findings suggest a general functional shift from higher-order cognitive regulation toward lower-level sensory processing across stimulus types. Notably, microstate transitions were less dynamic in individuals with MDD, indicating lower information entropy and a decreased frequency of microstate switching. Moreover, MDD patients exhibited prolonged engagement of anterior microstates, potentially reflecting sustained activation of self-referential and affective regulatory circuits, including the anterior cingulate cortex (ACC), independent of executive-control-associated networks. Functional connectivity analysis further revealed altered anterior–posterior coupling and disrupted integration within the fronto-central regions, which are considered critical for emotional appraisal. These findings suggest that MDD alters the balance between perceptual and regulatory networks during aesthetic processing, which may underlie the negative aesthetic preferences often observed in depression. Our study highlights EEG microstate analysis as a sensitive tool for capturing neural signatures of aesthetic experience and offers new insights into the dysfunctional brain dynamics associated with MDD. These results provide a foundation for developing neurophysiological markers and targeted interventions to modulate aesthetic-related brain activity in depressive disorders.</p>