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Schmitter, C. V.

Publications and source records attributed to Schmitter, C. V..

2 recordsLinked to original sources

Altered Neural Processing in Middle Frontal Gyrus and Cerebellum During Temporal Recalibration of Action-Outcome Predictions in Schizophrenia Spectrum Disorders

A key function of the perceptual system is to predict the (multi)sensory outcomes of actions and recalibrate these predictions in response to changing conditions. In schizophrenia spectrum disorders (SSD), impairments in this ability have been linked to difficulties in self-other distinction. This study investigated the neural correlates of the recalibration of action-outcome predictions to delays, the transfer of this process across sensory modality, and whether patients with SSD exhibit alterations in the underlying neural processes. Patients and healthy controls (HC) underwent fMRI while exposed to delays between active or passive button presses and auditory outcomes. A delay detection task assessed recalibration effects on auditory perception (unimodal trials) and its transfer to visual perception (cross-modal trials). In unimodal trials, HC exhibited reduced activation in left middle frontal gyrus (MFG) after recalibration, particularly for active movements, whereas this effect was reversed in SSD. In cross-modal trials, recalibration was linked to increased activation in bilateral cerebellum in HC, especially for active movements, a pattern significantly reduced in SSD. These findings suggest that unimodal temporal recalibration of action-outcome predictions in HC is reflected in reduced prediction error-related MFG activity, which is significantly reduced in SSD revealing potentially disrupted recalibration processes. Additionally, cerebellar engagement appears crucial for cross-modal transfer of recalibrated action-outcome timings, a process that may be impaired in SSD, leading to severe perceptual disturbances like hallucinations.

neuroscience↗

Facilitation of sensorimotor temporal recalibration mechanisms by cerebellar tDCS in patients with schizophrenia spectrum disorder and healthy subjects

Core symptoms in patients with schizophrenia spectrum disorder (SSD), such as hallucinations or ego-disturbances, have been associated with a failure of the forward model to adequately predict the sensory outcomes of self-generated actions. Importantly, depending on the requirements of the environment, forward model predictions must also be able to recalibrate flexibly, for example to account for additional delays between action and outcome. In this study, we aimed to investigate whether non-invasive brain stimulation via transcranial direct current stimulation (tDCS) can be used to improve these sensorimotor temporal recalibration mechanisms in patients and in healthy subjects. While receiving tDCS on the cerebellum, temporo-parietal junction (TPJ), supplementary motor area (SMA), or sham stimulation, patients with SSD and healthy control subjects were repeatedly exposed to delays between actively elicited or passively performed button press movements and auditory sensory outcomes. Effects of this procedure on temporal perception were assessed with a delay detection task. We found similar sensorimotor temporal recalibration effects in both SSD and healthy subjects. Furthermore, cerebellar tDCS facilitated recalibration effects in both groups. Our findings indicate that sensorimotor recalibration mechanisms may be preserved in SSD and highlight the importance of the cerebellum in both patients and healthy subjects for this process. Our results suggest that cerebellar tDCS could be a promising tool for addressing deficits in action-outcome monitoring and related adaptive sensorimotor processes in SSD, and potentially alleviating associated symptoms.

neuroscience↗