Dynamics of involuntary formation of EEG correlation patterns by biofeedback mechanism

The purpose of the work is to assess the dynamics of electroencephalogram (EEG) correlation development under involuntary control by biofeedback mechanism. Materials and Methods. The study involved 33 people (26 men and 7 women) aged 19-27 years. The paradigm of involuntary control was tested. The user did not have to arbitrarily change his/her state to achieve the desired color solution on the screen. The mode of color spectrum variation was determined by RGB channels, where each color was set according to correlation coefficients of EEG signals from a given pair of electrodes. The authors analyzed EEG correlation patterns in the biofeedback system through the color change on the screen. At the beginning, the user selected three most "pleasant" and three least "pleasant" colors. Feedback effect was multidirectional. Whenever the distance increased from the first to the fourth quantile for feedback experiments, the values were less than in the control. Whenever the distance decreased, the control values were less than the experimental ones. Results. A decrease in the RGB space mean square distance was revealed by the end of the experiment. Differences were also identified between the two study groups in the feedback experiments. The subjects were observed to maintain the dynamics during the experiment: if, in case of feedback, the distance to the preferred colors decreased, it decreased in the control experiment as well. The group approaching the target (preferred color) was initially at a larger distance from it, but had smaller values of roof-mean-square deviation (RMS).