Intrinsic, task-evoked and absolute gamma synchrony during cognitive processing in first onset schizophrenia

Cognitive deficits present from the first onset of schizophrenia are thought to arise from a core problem in neural synchrony. This is the first study to characterize the profile of gamma (30-100 Hz) synchrony (rather than power) and behavioral performance during higher-order cognitive processing in schizophrenia. Gamma synchrony was acquired from the EEG, and elicited by a Continuous Performance Test (CPT). We quantitated synchrony for regions associated with the fronto-parietal attention and visual networks for 59 young people with First Onset Schizophrenia (FOS) and 59 matched controls, facilitated by the BRAINnet.net data sharing initiative. We compared groups on gamma synchrony for intrinsic (pre-stimulus), task-evoked change (relative to baseline) and absolute (not relative to baseline) measures. Relationships between synchrony and CPT accuracy, symptoms and functioning were also assessed. FOS showed a reduced ability to modulate task-evoked changes in gamma synchrony, in the context of generally higher intrinsic and absolute synchrony, particularly in frontal regions. These gamma synchrony abnormalities in FOS were associated with performance on the CPT, but not with symptoms or functioning. Task-relevant changes in synchrony may be constrained by an overall excess of intrinsic background synchrony that is unrelated to specific task demands and this relates to cognitive performance. Results are in line with theoretical accounts of gamma synchrony as a core abnormality in schizophrenia, affecting functional connectivity in central executive circuits and causing cognitive symptoms. This study is the first to demonstrate that these gamma synchrony abnormalities are not limited to perceptual or lower-order cognitive processing.

Stream of consciousness: Quantum and biochemical assumptions regarding psychopathology

The accepted paradigms of mainstream neuropsychiatry appear to be incompletely adequate and in various cases offer equivocal analyses. However, a growing number of new approaches are being proposed that suggest the emergence of paradigm shifts in this area. In particular, quantum theories of mind, brain and consciousness seem to offer a profound change to the current approaches. Unfortunately these quantum paradigms harbor at least two serious problems. First, they are simply models, theories, and assumptions, with no convincing experiments supporting their claims. Second, they deviate from contemporary mainstream views of psychiatric illness and do so in revolutionary ways. We suggest a possible way to integrate experimental neuroscience with quantum models in order to address outstanding issues in psychopathology. A key role is played by the phenomenon called the "stream of consciousness", which can be linked to the so-called "Gamma Synchrony" (GS), which is clearly demonstrated by EEG data. In our novel proposal, a unipolar depressed patient could be seen as a subject with an altered stream of consciousness. In particular, some clues suggest that depression is linked to an "increased power" stream of consciousness. It is additionally suggested that such an approach to depression might be extended to psychopathology in general with potential benefits to diagnostics and therapeutics in neuropsychiatry.