# Altered neural processing in middle frontal gyrus and cerebellum during temporal recalibration of action-outcome predictions in schizophrenia spectrum disorders

## TL;DR

This study shows that people with schizophrenia spectrum disorders process action-outcome predictions differently in brain regions like the middle frontal gyrus and cerebellum, which may contribute to perceptual issues like hallucinations.

## Contribution

The study identifies altered neural processing in SSD during temporal recalibration of action-outcome predictions and its cross-modal transfer.

## Key findings

- Healthy controls showed reduced left middle frontal gyrus activation after recalibration, while SSD participants showed the opposite pattern.
- Cross-modal recalibration in healthy controls involved increased cerebellar activation, which was significantly reduced in SSD participants.
- Altered recalibration processes in SSD may lead to perceptual disturbances like hallucinations.

## Abstract

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 modalities, and whether participants with SSD exhibit alterations in the underlying neural processes. SSD participants 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.