A trend towards integration is notable in the development of studies related to the human brain. An interdisciplinary approach to the analysis of cerebral mechanisms of psychic functions is, in our opinion, particularly effective in studying specific kinds of human activity, such as verbal processes (reading and writing), based on various aspects of cognitive activity. This work deals with the results of a comprehensive electroencephalographic and neuropsychological examination of primary school pupils with dyslexia and dysgraphia. Our purpose was to elucidate the cerebral mechanisms of these disturbances and obtain additional data on the features of the ontogenetic development of the verbal function. METHODSWe examined 19 children aged 7-10 years (14 boys and 5 girls), including 11 right-handers, 4 ambidexters, 3 left-handers, and 1 left-hander trained to write with the right hand. They attended school together with normal children and suffered dysgraphia and dyslexia, which led to learning difficulties. Some of the children were good at mathematics (B.A.) and had greater than average intelligence according to the Wexler scale (A.N., Z.M.).The children's individual cards reflected data of neurological evaluation, neuropsychological testing, and EEG examination.Neuropsychological testing was carried out according to the pediatric version of Luria's technique [1,2]. The condition of higher psychic functions was evaluated with regard for a child's age. The evaluation system was as follows: 0, no disturbances; 1, mild disturbances (error rate less than 30%); 2, average gravity (error rate 30-70%); and 3, grave disturbances (error rate more than 70%). When it was difficult to evaluate a disturbance (e.g., it was between mild and average or between average and grave), we used an intermediate rating, i.e., 0-1, 1-2, or 2-3.The EEG of both hemispheres was recorded monopolarly or bipolarly from 12 derivations localized according to the 10-20 system: O 1 , O 2 , P 3 , P 4 , C 3 , C 4 , F 3 , F 4 , T 3 , T 4 , T 5 , and T 6 , at rest and during rhythmic photic stimulation or hyperventilation. To record the EEG, we used a Neurofax (Nihon Kohden) eight-channel electroencephalograph and a Biola twelve-channel computer-based electroencephalograph.Neuropsychological and EEG data were presented using the structural-organizational schemes described in detail earlier [3,4]. The schemes were based on the principles of topical diagnosis, i.e., description of brain Abstract -Comprehensive neuropsychological and electroencephalographic examination of children with dysgraphia and dyslexia demonstrated local EEG anomalies in various zones of the cortex in both hemispheres, mainly in the posterotemporal and/or anterior regions of the left and the posterotemporal regions of the right hemisphere. The character of speech disturbances depended considerably on the localization of the baseline EEG anomalies: disturbances of motor components of writing prevailed when these anomalies were localized in the anterior parts of the left hemisphere, w...