Disrupted sensory interhemispheric synchronization in schizophrenia: a frequency-resolved VMHC analysis

Aberrant interhemispheric functional connectivity has been implicated in the pathophysiology of schizophrenia. Voxel-mirrored homotopic connectivity (VMHC) provides a reliable measure of interhemispheric synchronization, yet the frequency-specific characteristics of VMHC alterations in schizophrenia remain poorly understood.

Resting-state functional magnetic resonance imaging data were analyzed in patients with schizophrenia and matched healthy controls. VMHC was computed across frequency bands, with particular focus on slow-4 and slow-5 oscillations. Group differences, as well as group-by-frequency interactions, were assessed to identify frequency-specific disruption.

Patients with schizophrenia exhibited significantly reduced VMHC within key sensory networks, including primary visual and sensorimotor regions. Frequency-specific analyses revealed higher VMHC at slow-5 compared with slow-4 in visual gyrus and subcortical regions. Significant group-by-frequency interaction effects were observed in the middle occipital gyrus and postcentral gyrus, with post-hoc analyses indicating selectively reduced slow-4 VMHC in patients with schizophrenia.

This study demonstrates frequency-dependent reductions of interhemispheric connectivity in schizophrenia, particularly within sensory systems. The findings highlight the disrupted integration of primary perceptual and motor-related processes as a core feature of schizophrenia and emphasize the utility of frequency-resolved VMHC analyses for refining our understanding of network dysfunction. Future longitudinal studies are warranted to determine the clinical significance of these frequency-specific alterations in illness progression and treatment response.