Relationship of spatial synchronization of θ-band bioelectric potentials of human EEG with the success of visual spatial task performance

Students (46 young men) were asked to memorize and reproduce the order and location (on a computer monitor) of signals. Two groups of subjects were formed according to how accurately they reproduced the true location and order of the signals. Subjects of the first group, in contrast to the second group, reproduced the signal location and order at a high accuracy and with few mistakes even in the first trials. EEGs were recorded prior to the test, during memorizing, and after completion of the task. In the initial state and after completion of the task, the two groups did not differ in the EEG θ-rhythm. During memorizing the signal sequence, an increase in the coefficients of coherence was recorded in the EEG θ band of the right brain hemisphere of the first-group of students; this was not characteristic of the second group. Three systems of connection with the foci of activity were determined in the right occipital, central, and frontal cortical areas, where the coherence of the EEG θ band was significantly higher during memorizing in the students that had exhibited a high accuracy of signal reproduction. Since the right hemisphere deals mainly with the perception of visual spatial information and it is more active in processing nonverbal and stereotyped signals, we have suggested that the students of two groups employed different strategies in solving the task during memorizing.