Reduced duration mismatch negativity elicited by the multi-feature 'optimal' paradigm in early-phase psychosis.

BACKGROUND: MMN and P3a are EEG-derived event related potentials that are thought to be prospective biomarkers for schizophrenia and, potentially, early-phase psychosis (EPP). METHODS: EPP (n = 12) and healthy control (HC; n = 35) participants listened to a multi-feature optimal paradigm with five deviant types (gap, duration, location, intensity, and frequency). RESULTS: There was a significant amplitude difference between the EPP and HC group with duration MMN (p = .02). No significant amplitude differences between groups were found for the P3a waveform. There were several correlations for the EPP group with the BNSS, SOFAS, and PANSS-general questionnaires. Length of illness was not associated with MMN or P3a. CONCLUSIONS: The optimal paradigm is suitable for eliciting multiple deviant types within a short amount of time in both clinical and healthy populations. This study confirms duration MMN deficits within an EPP group and that MMN is related to functional outcomes and positive and negative symptomology.

MMN and P3a Elicited by a Novelty Oddball Paradigm Are Not Reduced in Early-Phase Psychosis.

INTRODUCTION: The present study compared the mismatch negativity (MMN) and P3a waveforms among early-phase psychosis (EPP; n = 13) individuals and healthy controls (n = 30) to contribute to the research on these waveforms as potential biomarkers for schizophrenia. METHODS: MMN and P3a were elicited with a novelty paradigm using complex stimuli with electrophysiological technology. RESULTS: No significant group differences of amplitude were observed with either waveform. Increased asociality and blunted affect were associated with a reduction in both MMN and P3a waveforms indicating a relationship between these negative symptoms and cognitive deficits. Good social and occupational functioning correlated with improved MMN and P3a waveforms in the EPP group. CONCLUSIONS: This study suggests that MMN and P3a may be more appropriately used as an indicator of illness progression and symptomology rather than a biomarker in the early phase of the illness.

MMN and P3a elicited by a novelty paradigm in healthy controls: An investigation of sex differences.

The mismatch negativity (MMN) and P3a waveforms are both markers of auditory change detection. MMN indicates deficits in performing auditory change-detection tasks, while the P3a reflects the evaluative and conscious aspect of orienting to the sound. Understanding the role biological sex has concerning these waveforms would provide insight into overall brain-based differences, but whether sex differences exist to such a degree that it can moderate the effect of auditory change detection is not certain. Thus, the purpose of this study was to examine potential sex differences in MMN and P3a elicited by a novelty paradigm in a healthy population. The results showed no significant differences between males and females. This study proves to be useful by adding to the limited literature on the topic and by providing a foundation of knowledge regarding sex differences in auditory change detection mechanisms within the population.