First graders (aged 7-8) in a public elementary school served as subjects for this study. The structural components of their speech were analyzed to determine speech maturity level; total EEG activity was analyzed to assess the functional maturity of brain structures. Results showed that children with levels of speech below the age norm exhibited abnormal EEG patterns suggesting immaturity of the cerebral cortex and fronto-thalamic regulatory system, as well as impairments in the functioning of the mesodiencephalic structures and nonspecific activation systems. Abnormalities in the functioning of brain regulatory systems and the presence of local abnormalities in EEG activity of deep origin are important factors in determining the severity of functional speech impairments.