ИСТИНА

Aphasia patients and 4-year-old children understand passive structures with reverse word order better than with direct order. It was explained by the word order strategy with the rule "The first name is Agent". It was assumed that the right hemisphere functions participate in processing this rule. In our study we check whether a strategy based on word order is used in understanding of grammatical structures by primary schoolchildren. Methods: (1) Computer-based sentence-to-picture test of understanding reversible grammatical constructions (GCs): active direct (AD), active reverse (AR), passive direct (PD) and passive reverse (PR). (2) neuropsychological assessment adapted for children (Akhutina, et al., 2016). 93 first-graders, 93 second-graders and 63 third-graders participated in the study. Data processing: In order to divide children into groups that differ in the productivity of understanding of the four types of GCs k-means clustering was used . 4 clusters were extracted. In cluster 1 there were a small number of children with low productivity (6, 0 and 2 children), they were excluded from further analysis . Cluster 2 included children with greater productivity in understanding PR structures than PD (group 1) and cluster 3, with a better understanding of PD structures (group 2). Cluster 4 included the most successful children with a good understanding of passive structures (group 3). Results: The distribution of children by group in grades was as follows: 26, 31, 43% (grade 1), 19, 24, 57% (grade 2), 20, 21, 59% (grade 3). Analysis of the response time to different GCs in children of the three groups showed significant differences in all grades. The increase in time in group 1 in the grade 1 occurred in the order AD<PR<AR<PD , in the grades 2 and 3 – AD<AR<PR<PD . The difference in RT between AD and PR in grade 1 was minimal, but it noticeably increased in grades 2 and 3. The same order of АD-АR-PR-PD was observed in group 3, but only in grade 1. In all other cases PD precede PR. Neuropsychological analysis showed the lowest rates of group 1 in all grades. It is noteworthy that the index of right hemisphere functions in group 1 was not significantly different from group 2 and group 3 in grade 1, but not in grades 2 and 3. Thus, our data suggest that the best processing of PR structures in grade 1 and in classes 2-3 has to be explained by different mechanisms. The work is supported by the RFBR, project no. 16-06-01001.