Changes in interhemispheric functional asymmetry, estimated by indices of induced activity, as a result of stimulatory teaching (training of the symbolic function) have been studied in 2-years-old children. Statistically significant increase in the asymmetry has been observed in central and parietal areas of the cortex. Possible causes and mechanisms of the phenomenon are considered. A conclusion is made that cognitive analysis and involuntary attention improve in the process of development of the symbolic function.