Attenuation of mismatch negativity (MMN) and novelty P300 in schizophrenia patients with auditory hallucinations experiencing acute exacerbation of illness

• Reduced novelty P3 amplitudes in SZ patients, compared to healthy controls (HCs).
• Reduced MMN amplitudes to both deviant and novel stimuli in SZ patients (vs. HCs).
• Novelty MMN amplitudes were correlated trait aspects of illness.
• Novelty P3 amplitudes were correlated with measures of hallucinatory state.

This study examined measures of early auditory feature analysis, including the mismatch negativity (MMN) and novelty P300 (NP3) in schizophrenia patients (SZ) with persistent auditory hallucinations (AH) during an acute psychotic episode requiring hospitalisation. Neuroelectric activity was recorded in 10 SZ patients and 13 healthy controls (HC) during a passive auditory oddball task including novel environmental sounds. MMN/NP3 amplitudes and latencies were compared between groups and were correlated with trait (PSYRATS) and state measures of AH severity as well as clinical symptom ratings in SZs.SZ patients (vs. HCs) exhibited reduced MMN amplitudes to both rare deviant and novel stimuli, as well as reduced NP3 amplitudes. Additionally, while novelty MMN amplitudes were correlated with measures of hallucinatory trait, NP3 amplitudes were correlated with measures of hallucinatory state. Therefore, in acutely ill SZ patients, individual components of the auditory novelty detection mechanism may be differentially sensitive to varying aspects of AHs.