Analysis of Cognitive and Interhemispheric Features in Normal Bilinguals and in Patients with Neurological Diseases and Mental Disorders

Background : the relationship between the effectiveness of bilingualism, interhemispheric interaction and the cognitive sphere poorly understood. The aim was to assess combination factor of bilingualism in frame of “cognitive-lateral model” and to determine statistical characteristics of empiric parameters depending of bilingualism. Participants and Methods : 21 healthy persons were examined. Neurocognitive methods included the Compass and Tower of Hanoi tests. The profile of the lateral organization and the leading arm were determined. The intensity of interhemispheric interaction was assessed by determining the maximum angle of preservation of stereopsis. The set of factors of bilingualism was empirically assessed within the framework of the “cognitive-bilateral model”. The statistical characteristics of the empirical variables of the model are determined depending on the degree of mastery of a second/several languages. Results : correlations were obtained between the indicators of the lateral organization profile and the leading hand in the Annette test (r = 0.34), scores in the “Compass” task (r = 0.33), and the number of moves in solving the “Tower of Hanoi” problem (r = −0.45) and the intensity of interhemispheric interaction after cognitive load (r = −0.38). Using discriminant analysis, the discriminatory parameters of the model were determined, characterizing cognitive psychological characteristics, an indicator of lateral organization and the intensity of interhemispheric interaction in relation to the “effectiveness of bilingualism”. The discriminatory function included variables from the “Compass” and “Tower of Hanoi” cognitive tests with the greatest contribution from the lateral organization and leading hand profile indicators Classification based on the difference between group centroids was more than 90%. Conclusions : effectiveness of bilingualism study based on cognitive-lateral model could be perspective in studying of psychiatric and neurological pathology.