Right and left brain hemispheres activation in the representatives of two different cultures

A routine EEG combined with alpha-index and spatial synchronization (SpS) analysis was performed in two different populations, native citizens of the Far North-East of Russia and new immigrants to the Far North-East. The investigation was performed in the initial resting state, in the process of mental arithmetic and of imagination of a natural landscape. According to the significant increase in spatial synchronization during task solution, all subjects were divided into 3 groups: I. Mental imagination increased SpS in the right hemisphere (> .7) while mental arithmetic did not increase SpS in either hemisphere. - II. Mental arithmetic increased SpS in the left hemisphere (.7) while mental imagination did not increase SpS in either hemisphere. - III. Mental imagination increased SpS in the right hemisphere while mental arithmetic increased SpS in the left hemisphere. In group I, alpha-index was relatively reduced in the left hemisphere before task performance and in both hemispheres during mental arithmetic, while mental imagination was accompanied by high alpha-index. In group II both tasks, and especially imagination, caused a decrease in the alpha-index. Native citizens and children under age 10 more often belonged to the group I and adult new immigrants - to the group II. The nature of the brain hemisphere activation is discussed in terms of the peculiarity of brain hemisphere functions - organization of the poly - monosemantic context.