Development of Biomarkers Potentially Sensitive to Early Psychosis Using Mismatch Negativity (MMN) to Complex Pattern...

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Psychiatry

Background:

• Mismatch negativity (MMN) is an objective electrophysiological measure of auditory deviance detection.
• Simple MMN (sMMN) is impaired in schizophrenia but lacks face validity due to adaptation confounds and is unreliable in early psychosis.
• Complex MMN (cMMN) tasks better isolate deviance detection but typically yield small amplitudes, limiting their biomarker potential.

Purpose of the Study:

• To develop and validate a novel dual-rule complex MMN (cMMN) paradigm.
• To assess if the dual-rule cMMN paradigm enhances MMN amplitude compared to single-rule tasks.
• To evaluate the potential of the enhanced cMMN as a biomarker for early psychosis.

Main Methods:

• Twenty-nine healthy individuals participated in the study.
• A dual-rule cMMN paradigm was implemented, involving alternating sound lateralization and pitch.
• Deviants violated both lateralization and pitch rules; responses were compared to a one-rule cMMN task.

Main Results:

• The dual-rule cMMN task elicited significantly larger early and late MMN responses compared to a one-rule cMMN task.
• The dual-rule early cMMN amplitude was comparable to amplitudes elicited by simple MMN (sMMN) paradigms.
• These findings suggest additivity of deviance detection in the dual-rule paradigm.

Conclusions:

• The dual-rule cMMN paradigm effectively increases MMN amplitude by combining multiple rules.
• This enhanced cMMN shows promise as a more sensitive biomarker for detecting psychosis, potentially even before symptom onset.
• The increased amplitude may improve the ability to differentiate between healthy and clinical populations.