Psychotic symptoms such as hearing voices or feeling that thoughts are inserted may arise from failures in the brain's prediction and self-monitoring systems. Normally, when people talk internally, the brain sends copies of motor commands to auditory regions and suppresses them, helping distinguish self-generated from external input. When this suppression malfunctions, predicted inner speech can become perceptually salient and misattributed as external. Neuroimaging meta-analyses showed that psychosis-spectrum participants had increased activity in motor-related regions for inner speech and decreased grey matter in auditory cortices and anterior cingulate cortex. These regions form inversely coupled networks, supporting a hierarchical predictive-processing account where disruption distorts self-awareness.
Aberrations in inner speech are linked to psychotic symptoms such as thought insertion and auditory verbal hallucinations, which may arise from failures in prediction and source monitoring. Normally, efference copies of speech motor commands suppress auditory responses to self-generated input; if suppression malfunctions, predicted auditory input becomes perceptually salient. Impaired self-monitoring regions (e.g., anterior cingulate cortex) may cause inner speech to be misattributed as external. Neuroimaging meta-analyses of neurotypical participants and psychosis spectrum participants showed increased activity in motor-related regions (e.g., ventral premotor cortices) and decreased grey matter in auditory cortices and ACC. These regions form distinct, inversely coupled audiomotor networks, supporting the proposal that psychotic symptoms derive from hyperactivation in inner speech regions producing insufficiently suppressed efference copy signals.