Article

Neural synchrony indexes disordered perception and cognition in schizophrenia

Department of Psychiatry, Veterans Affairs Boston Healthcare System, Harvard Medical School, Psychiatry 116A, 940 Belmont Street, Brockton, MA 02301, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 01/2005; 101(49):17288-93. DOI: 10.1073/pnas.0406074101
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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.

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    • "| to optimize learning . Conversely , our interface - controlled non - theta state may be a drug - free , non - lesion model of psychiatric / cognitive disorders such as schizophrenia , autism and age - related memory impairments , thought to result from desynchronization of critical brain systems ( Behrendt and Young , 2004 ; Spencer et al . , 2004 ; Asaka et al . , 2005 ; Donkers et al . , 2011 ; Doesburg et al . , 2013 ) . Continuation of this approach will enhance our knowledge of the roles of LFPs as well as their relation to signals in other bandwidths and time frames ( Bullock , 1997 ) , with the goal of a comprehensive description of electrophysiological mechanisms of infor"
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    • "Positive, negative, and general symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS; Kay et al., 1987). We specifically probed the relationship between conceptual disorganization (PANSS item P2) and perceptual organization, since many prior studies have uncovered relations between the two (Keane et al., 2014; Silverstein et al., 2013; Spencer et al., 2004; Uhlhaas et al., 2006). The Premorbid Adjustment Scale (PAS; Cannon-Spoor et al., 1982) was administered to assess social isolation, peer relationships, scholastic performance, school adaptation, and socialsexual aspects of life prior to illness onset. "
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    • "Most of the studies failed to find correlation between P1 amplitude measures and clinical symptoms (Butler et al., 2005; Schechter et al., 2005). However relationships were seen when the visual evoked response was assessed through brain oscillation analysis (Spencer et al., 2004). Despite the progress in localizing neural dysfunctions within the visual system and related areas, there is an urgent need for a more consistent definition of the frequency of basic visual deficits, their reliability and the association with clinical variables. "
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