Phase interaction between high-and low-frequency EEGrhythms and their role in cognitive processes

From 27 healthy boys and 29 girls aged 18 to 26 years investigated the intraandinterhemispheric phase of interaction between high- and low-frequency EEGrhythms of reproduction and measure short time intervals in the presence and absenceof feedback on performance. In a preliminary study investigated the verbal andnonverbal intelligence, levels of extraversion and neuroticism, particularly the lateralorganization of the brain with the definition of a leading hand and speech hemisphere.Time Intervals in the series given as non-verbal stimuli (white square with a side of2 cm, which appears in the center of a darken monitor) at another series - the figures(for measuring length of time Interval). Tested persons have been double-clicking on the«gap» to reproduce or measure time intervals. Like a feedback signal was a percentageexpressed relative error of measuring reproduction or specified time interval. EEGwere recorded using 24-channel analyzer encephalograph in the following diversionof the electrodes: Cz, Fz, Pz, F3, F4, C3, C4, P3, P4, T3, T4, T5, T6, O1, O2 inaccordance with the scheme «10-20%». To study of phase interactions between highandlow-frequency components of EEG used Wavelet and bispectral analysis calculatethe function of bicohere. As an integral characteristic of the phase-level interactionsbetween the rhythms of the EEG used half the sum of the values of this function inthe investigated frequency range of the EEG (0,5-70 Hz). To analysis of correlationsbetween the studied parameters calculated a Spearman rank correlation coefficient.To assess the influence of the investigated factors («sex», «stage of activity» «kind ofactivity») on the phase interaction using ANOVA analysis for repeated observations.Strong intra-and interhemispheric phase interaction between high-and lowfrequencyEEG rhythms was found . Most often, these interactions are observed betweengamma rhythms and low-frequency components of the EEG (0,5-30 Hz), as well asbetween different frequencies of gamma rhythm (30-70 Hz). The dependence of theinteractions in the factors «sex», « stage of activity», «kind of activity» was established.The correlation between phase-level interactions and the indicators of intelligence,extraversion, neuroticism, the lateral organization of the brain and the accuracy of timeperception. It is assumed that along with the spatial frequency synchronization of brainelectrical activity it have are an effective mechanism of functional association neurons.Obtained results and published data suggest that the investigated phase interactionsplay an important role in cognitive processes in the consciousness mechanisms. Thehigh rate of change of the detected phase interactions, and some literature data suggestthat these interactions cant be only the result of synaptic facilitation and can be as theinteractions of distant field between neurons.

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