Interhemispheric asymmetry of the EEG rhythms coupling accompanies cognitive awakening during bimanual performance of a psychomotor test

Awakening is a transitional process from sleep to wakefulness. There is a certain restructuring in the work of brain structures during this period, which further allows a person to perform conscious activity. The study of interhemispheric asymmetry of amplitude–amplitude couplings of EEG rhythms was carried out. A psychomotor test was used in experiments. This test allows us to observe the moments of falling asleep and waking up when performing monotonous work. Multichannel EEG was recorded simultaneously with the test. The data of 14 subjects who reached the second stage of sleep during the experiment were analyzed. The selected 20 s EEG segments prior to awakening were processed using a continuous wavelet transform based on the “mother” complex Morlet wavelet. The Kendall correlation coefficient was used to evaluate the measure of EEG rhythms coupling. Quantitative changes in the couplings of EEG rhythms were revealed as the moment of awakening approached: in the two most distant time intervals, the total number of asymmetric connections was five to three, and in the two closest segments, there was only one coupling of EEG rhythms. This is not just a decrease in the number of connections, but also a change of EEG rhythms coupling throughout the entire 20-s segment. The dynamic nature of the EEG rhythms coupling in the hemispheres before awakening to resume the task is shown, which may indicate the dynamic relationship of structural and functional associations of the brain.