Reductions in Complex Mismatch Negativity to Extra Tone Gestalt Pattern Deviance in First-Episode Schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Auditory Processing

Background:

• Simple mismatch negativity (sMMN) is reduced in chronic schizophrenia but less so in first episode schizophrenia spectrum (FESz).
• Complex mismatch negativity (cMMN), reflecting acoustic pattern analysis, is reduced in schizophrenia but understudied in FESz.
• cMMN's computational demands may reveal sensitive auditory processing deficits early in psychosis.

Purpose of the Study:

• To investigate cMMN in FESz individuals compared to healthy controls (HC).
• To determine if cMMN is a sensitive biomarker for early schizophrenia pathophysiology and its relation to social functioning.

Main Methods:

• Twenty-two FESz individuals and 22 HC underwent auditory tasks assessing sMMN (pitch, duration deviants) and cMMN (extra tone deviant).
• Data analysis focused on MMN amplitude differences between FESz and HC groups.

Main Results:

• FESz individuals showed no significant reduction in pitch- or duration-deviant sMMN.
• A large reduction in extra-tone cMMN was observed in FESz individuals compared to HC.
• Reduced cMMN amplitude in FESz was associated with poorer social functioning.

Conclusions:

• Impaired complex auditory pattern processing (cMMN) is evident early in schizophrenia spectrum disorders.
• cMMN serves as a sensitive indicator of early pathology and its impact on social functioning.
• Further research in at-risk populations is needed to validate cMMN as a prodromal schizophrenia biomarker.