Spectral features of the electroencephalogram (EEG) are essential for providing clinically
relevant biomarkers in schizophrenia (SZ). Despite literature indicating altered short-scale
neural dynamics in SZ, however, band-limited power (BLP) indices are rarely assessed
in a time-resolved manner. To address this, here we evaluated static and dynamic BLP
indices in a sample of 30 SZ patients and 31 healthy control (HC) individuals. Guided
by recent findings on power spectral dynamics in SZ, we estimated total, and decomposed
fractal and oscillatory BLP in a sliding window manner from resting-state EEG recordings
collected in eyes-closed resting-state. The SZ cohort was characterized by elevated
baseline of total fractal power (p = 0.0015, |r| = 0.4073), while its temporal variability
was comparable between the two study groups. On the other hand, spectral power in
the alpha (p < 10−4, d = 1.0503) and beta (p = 0.0022, |r| = 0.3925) regimes exhibited
reduced fluctuation in SZ compared to HC, with no between-group differences in their
baselines. Furthermore, alpha variability could be attributed to alterations in isolated
oscillatory activity, while variability in beta-BLP over the dorsal attention network
was found correlated with negative symptoms in SZ (Spearman r = −0.4994, p = 0.0055).
Finally, surrogate data testing indicated altered phase dynamics in SZ as a potential
mechanism for diminished BLP fluctuations.
