Spatial characteristics of the theta rhythm EEG with different performance of intellectual activity

The students (46 persons, 19-21 years old) were offered to remember and recall the location and the order of the certain sequence of signals on the monitor. Two groups of students were defined basing on their degree of approximation to the correct location of the signal of a sequence. The students from the first group, in contrast to the second one, demonstrated high accuracy of prediction for the signal sequence location and smaller number of mistakes, starting from the first trials. EEG was registered before the task (background), during task remembering and task performance. In the background EEG and during task performance there were no differences between coherent ratios of the theta-rhythm of the two groups. However, during remembering we observed increase in the coherent ratio of the theta-rhythm in the right hemisphere of the students from the first but not the second group (О2-Р4 (р=0,041), О2-С4 (р=0,049), 02-F4 (р=0,004), О2-Т4 (р=0,014), Р4-С4 (р=0,013), Р4-Т4 (р=0,032), C4-F4 (р=0,012), Т4-С4 (р=0,025). Since the right hemisphere deals mainly with spatial perception of the information and is more active at processing of nonverbal and stereotyped signals, we suggest that students belonging to different groups employed different strategies of processing of the task during remembering.