Oscillation in Motion: Dissociable Periodic and Aperiodic EEG Markers of Baseline Cognition and Treatment Response Following Exercise in Schizophrenia Spectrum Disorders

Background Schizophrenia Spectrum Disorders (SSD) are characterized by pervasive cognitive impairments and clinical symptoms, often refractory to pharmacological treatment, mirroring altered electrophysiological brain activity. These neurophysiological disruptions reflect a core imbalance in excitation–inhibition (E/I) dynamics. While exercise has emerged as a promising adjunctive therapy for residual symptoms, the mechanisms driving treatment response remain unclear. Methods In this study, we utilized electroencephalography (EEG) to assess the aperiodic exponent as a proxy for cortical E/I balance, alongside individual alpha peak frequency (iAPF) and theta power as markers of cognitive functioning. Following a cross-sectional comparison with healthy controls (HC, n  = 60), the SSD group ( n  = 58) underwent a 12-week longitudinal exercise intervention to evaluate treatment-related shifts in these EEG-based metrics and their clinical correlates. Results At baseline, patients exhibited localized occipital hyperexcitability, characterized by a flatter aperiodic exponent compared to HC. However, the higher a patient’s cognitive functioning was, the steeper was their global aperiodic exponent, suggesting that a degree of compensatory inhibitory tone may protect cognitive function. Longitudinally, post-intervention general psychopathological recovery measured by PANSS general was uniquely tracked by a global flattening of the aperiodic exponent. In contrast, cognitive gains were related both to a parietal steepening of the aperiodic slope and increases in frontal iAPF during eyes-closed rest. Conclusions These findings reveal a dissociation between EEG-based markers of E/I balance and oscillatory pacing, where they serve as distinct, region- and state-dependent biomarkers of clinical and cognitive treatment response in SSD, respectively. This establishes a neurophysiological framework for monitoring exercise-related neuroplasticity and provides a target for personalized intervention strategies.