title: Neural synchrony indexes disordered perception and cognition in schizophrenia.
abstract: Current views of schizophrenia suggest that it results from abnormalities in neural circuitry, but empirical evidence in the millisecond range of neural activity has been difficult to obtain. In pursuit of relevant evidence, we previously demonstrated that schizophrenia is associated with abnormal patterns of stimulus-evoked phaselocking of the electroencephalogram in the gamma band (30-100 Hz). These patterns may reflect impairments in neural assemblies, which have been proposed to use gamma-band oscillations as a mechanism for synchronization. Here, we report the unique finding that, in both healthy controls and schizophrenia patients, visual Gestalt stimuli elicit a gamma-band oscillation that is phase-locked to reaction time and hence may reflect processes leading to conscious perception of the stimuli. However, the frequency of this oscillation is lower in schizophrenics than in healthy individuals. This finding suggests that, although synchronization must occur for perception of the Gestalt, it occurs at a lower frequency because of a reduced capability of neural networks to support high-frequency synchronization in the brain of schizophrenics. Furthermore, the degree of phase locking of this oscillation is correlated with visual hallucinations, thought disorder, and disorganization in the schizophrenia patients. These data provide support for linking dysfunctional neural circuitry and the core symptoms of schizophrenia.
authors.affiliation: Department of Psychiatry, Veterans Affairs Boston Healthcare System, Harvard Medical School, Psychiatry 116A, 940 Belmont Street, Brockton, MA 02301, USA.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Spencer
authors.forename: Paul G
authors.initials: PG
authors.lastname: Nestor
authors.forename: Ruth
authors.initials: R
authors.lastname: Perlmutter
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Niznikiewicz
authors.forename: Meredith C
authors.initials: MC
authors.lastname: Klump
authors.forename: Melissa
authors.initials: M
authors.lastname: Frumin
authors.forename: Martha E
authors.initials: ME
authors.lastname: Shenton
authors.forename: Robert W
authors.initials: RW
authors.lastname: McCarley
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000209:etiology* / Q000503:physiopathology; D003221:Confusion / Q000209:etiology; D004558:Electric Stimulation; D004569:Electroencephalography; D004594:Electrophysiology; D006212:Hallucinations / Q000209:etiology; D006801:Humans; D008875:Middle Aged; D010465:Perception; D012559:Schizophrenia / Q000209:etiology* / Q000503:physiopathology*