[Segmental structure of the EEG alpha activity in adolescents with disorders of schizophrenic spectrum].
ABSTRACT The EEG records of 39 healthy adolescents and 45 age-matched schizophrenic patients were analyzed. The broad-band EEG spectral analysis and segmental analysis of the alpha-activity revealed significant differences between the groups. Schizophrenics differed in a decreased spectral power for the alpha2 and betal frequency bands and increased power for the delta and theta bands. Also, in schizophrenic adolescents, quasi-stationary alpha-rhythm segments were longer, and within-segmental EEG amplitudes were higher than in the healthy subjects; the amplitude variability and the steepness of transitions between neighbor segments were increased. The results of the EEG segmental analysis suggest a disintegration of local cortical neuronal ensembles in schizophrenia.
SourceAvailable from: Arcady Putilov[Show abstract] [Hide abstract]
ABSTRACT: The three-dimensional cube-in-globe model predicts the possibility to delineate six main adaptive abilities of the sleep – wake cycle (Putilov & Putilov, 2005). Such prediction led to the inclusion of a new sixth scale named “daytime wakeability” (Putilov & Putilov, 2006; Putilov, 2007) in the Sleep-Wake Pattern Assessment Questionnaire (SWPAQ; Putilov, 1990, 2000). This new scale permits self-assessment of the ability to keep waking at daytime in sleep provoking conditions. In the study reported here we applied the procedure of adaptive segmentation of the EEG record (SECTION 0.1®, Human Brain Research Group, Moscow State University) to determine whether sleep deprivation changes the temporal pattern of alpha activity and, if yes, whether this change is associated with state and trait self-measures of alertness/sleepiness including a score on “daytime wakeability” scale. In the course of sustained wakefulness, EEG was recorded nine times with three-hour intervals in frontal and occipital derivations in 39 healthy subjects. The procedure of adaptive segmentation allowed cutting EEG records on quasi-stationary segments and determining such characteristics of each segment as within-segmental amplitude, coefficient of its variation and segment length. These characteristics obtained in the morning hours on the first and second experimental days were compared. They were found to increase in the second morning, when eyes are open, but do not change when eyes are closed. It was also documented that “daytime wakeability” score along with other trait and state self-measures of alertness/sleepiness can serve as predictors of the response of alpha waves to sleep deprivation.Biological Rhythm Research 02/2008; 39(1):21-37. DOI:10.1080/09291010701233825 · 1.22 Impact Factor
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ABSTRACT: In this paper we aim to show that phenomenal consciousness is realized by a particular level of brain operational organization and that understanding human consciousness requires a description of the laws of the immediately underlying neural collective phenomena, the nested hierarchy of electromagnetic fields of brain activity - operational architectonics. We argue that the subjective mental reality and the objective neurobiological reality, although seemingly worlds apart, are intimately connected along a unified metastable continuum and are both guided by the universal laws of the physical world such as criticality, self-organization and emergence.Chaos Solitons & Fractals 10/2013; 55:13-31. DOI:10.1016/j.chaos.2013.02.007 · 1.50 Impact Factor
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ABSTRACT: We apply flicker-noise spectroscopy (FNS), a time series analysis method operating on structure functions and power spectrum estimates, to study the clinical electroencephalogram (EEG) signals recorded in children/adolescents (11 to 14 years of age) with diagnosed schizophrenia-spectrum symptoms at the National Center for Psychiatric Health (NCPH) of the Russian Academy of Medical Sciences. The EEG signals for these subjects were compared with the signals for a control sample of chronically depressed children/adolescents. The purpose of the study is to look for diagnostic signs of subjects' susceptibility to schizophrenia in the FNS parameters for specific electrodes and cross-correlations between the signals simultaneously measured at different points on the scalp. Our analysis of EEG signals from scalp-mounted electrodes at locations F3 and F4, which are symmetrically positioned in the left and right frontal areas of cerebral cortex, respectively, demonstrates an essential role of frequency-phase synchronization, a phenomenon representing specific correlations between the characteristic frequencies and phases of excitations in the brain. We introduce quantitative measures of frequency-phase synchronization and systematize the values of FNS parameters for the EEG data. The comparison of our results with the medical diagnoses for 84 subjects performed at NCPH makes it possible to group the EEG signals into 4 categories corresponding to different risk levels of subjects' susceptibility to schizophrenia. We suggest that the introduced quantitative characteristics and classification of cross-correlations may be used for the diagnosis of schizophrenia at the early stages of its development.Physica A: Statistical Mechanics and its Applications 07/2011; 391:1179. DOI:10.1016/j.physa.2011.09.032 · 1.72 Impact Factor