Dissociable anterior and posterior beta-burst dynamics track thought disorder in schizophrenia.

Abstract

Thought disorder in schizophrenia likely reflects disrupted maintenance of internal models during predictive processing. Beta oscillations have been proposed to index top-down predictive signalling, but prior resting-state studies have focused on spectral power, overlooking transient burst dynamics that potentially stabilize and reinstate internal representations, especially in the default mode network (DMN). Resting-state magnetoencephalography was acquired from 25 patients (7 females) with schizophrenia and 25 matched controls (8 females) between May 2024 and October 2025. Beta bursts (15-30&#xa0;Hz) were extracted from source-localized cortical time series, and burst rate, duration, power, and inter-regional synchrony were quantified. Associations with computationally derived semantic and syntactic speech features reflecting thought disorder were assessed using principal-component regression in the patient group. Conventional beta power did not differ between groups after correction. In contrast, beta-burst dynamics showed significant group-by-anterior-posterior-position interactions for burst rate (<i>p</i>&#xa0;=&#xa0;0.018), power (<i>p</i>&#xa0;=&#xa0;0.0014), and duration (<i>p</i>&#xa0;&lt;&#xa0;0.001). Within the DMN, patients showed shorter inferior parietal burst duration (<i>t</i>(46.0)&#xa0;=&#xa0;-2.74, FDR-adjusted <i>p</i>&#xa0;=&#xa0;0.0343) and increased burst synchrony within left prefrontal cortex (<i>t</i>(31.0)&#xa0;=&#xa0;2.81, FDR-adjusted <i>p</i>&#xa0;=&#xa0;0.0343) and between prefrontal cortices (<i>t</i>(29.8)&#xa0;=&#xa0;2.73, FDR-adjusted <i>p</i>&#xa0;=&#xa0;0.0423). Within the patient group, burst components were associated with speech organization (<i>R</i>² = 0.47, <i>F</i>(3,19)&#xa0;=&#xa0;5.66, <i>p</i>&#xa0;=&#xa0;0.006), driven by the inferior parietal burst-duration component (&#x3b2; = -0.55, <i>p</i>&#xa0;=&#xa0;0.0036), but did not relate to overall clinical severity. The modest patient sample, short resting-state recording, cross-sectional design, and lack of laminar specificity limit causal and mechanistic inference; burst-speech associations require replication. Schizophrenia is associated with dissociable anterior and posterior beta-burst abnormalities that track objective speech markers of thought disorder. These findings suggest impaired hierarchical coordination of predictive beta signalling as a candidate neurophysiological account linking intrinsic network dysfunction to disorganized thought.