Long-range gamma phase synchronization as a compensatory strategy during working memory in high-performing patients with schizophrenia.

TitleLong-range gamma phase synchronization as a compensatory strategy during working memory in high-performing patients with schizophrenia.
Publication TypeJournal Article
Year of Publication2018
AuthorsSo RP, Kegeles LS, Mao X, Shungu DC, Stanford AD, Chen C-MA
JournalJ Clin Exp Neuropsychol
Volume40
Issue7
Pagination663-681
Date Published2018 09
ISSN1744-411X
KeywordsAdolescent, Adult, Electroencephalography, Electroencephalography Phase Synchronization, Female, Frontal Lobe, Functional Laterality, Gamma Rhythm, gamma-Aminobutyric Acid, Humans, Male, Memory, Short-Term, Middle Aged, Neuroimaging, Occipital Lobe, Prefrontal Cortex, Psychomotor Performance, Schizophrenia, Schizophrenic Psychology, Young Adult
Abstract

Working memory deficits in schizophrenia may be associated with impairments in the integration of neural activity across a distributed network of cortical areas. However, evaluation of the contribution of this integration to working memory impairments in patients is severely confounded by behavioral performance. In the present multidimensional-neuroimaging study, measures of neural oscillations at baseline and during a working memory task, baseline gamma-aminobutyric acid (GABA) level in the left dorsolateral prefrontal cortex (DLPFC), and behavioral performance were obtained. Controlling behavioral performance by recruiting only "high-performing" patients with schizophrenia, we investigated whether the strength of cross-area communications differs between patients with schizophrenia and healthy participants under accurate and equivalent behavioral performance. Results of phase-locking value indicated that these high-performing patients recruited significantly more between frontal and occipital regions in the left hemisphere, t(13) = -2.16, p = .05, Cohen's d = -1.20, and between frontal and temporal regions in the right hemisphere, t(13) = -2.63, p = .02, Cohen's d = -1.46. These cross-area communication patterns may be associated with visuoverbal and visuospatial working memory networks of the left and right hemispheres, respectively. Moreover, correlations of patient's cross-area communication with in vivo GABA levels of the left DLPFC revealed a significant positive relationship (r = .77, p = .04), demonstrating that the critical role of GABA functions in gamma band oscillations may go beyond local neuronal assemblies in the left DLPFC. Altogether, these exploratory findings point to the heterogeneity among schizophrenia patients and highlight the notion that high-performing patients may engage in potential compensatory mechanisms and may represent a subgroup of patients that may be categorically or dimensionally divergent in psychopathology.

DOI10.1080/13803395.2017.1420142
Alternate JournalJ Clin Exp Neuropsychol
PubMed ID29388507
Grant ListR01 HD086168 / HD / NICHD NIH HHS / United States
R01 MH075895 / MH / NIMH NIH HHS / United States
S10 OD021782 / OD / NIH HHS / United States
Related Institute: 
MRI Research Institute (MRIRI)

Weill Cornell Medicine
Department of Radiology
525 East 68th Street New York, NY 10065