Role of neocortical association structures in the spatiotemporal organization of brain potentials in children during perception of sensory stimuli of different modalities.

Abstract

1. Correlation analysis of the EEG showed that in infants in the second year of life the spatiotemporal organization of brain potentials during the reception of information about an object through auditory or visual channels differs and depends not only on the modality of the stimulus but also in its semantic meaning. 2. During the perception of monomodal and polymodal semantically meaningful stimuli, whether words or objects, the greatest increase in the strength of correlations between potentials is found in the left inferior parietal zone. Perception of familiar words and familiar complex stimuli also increases by 2–2.5 times the number of high correlations in the frontal zone of the dominant hemisphere. 3. Synchronization of potentials of the neocortical association areas with those of projection areas of corresponding modality to the stimulus is increased most of all during perception of sensory stimuli of different modalities: For instance, on presentation of verbal stimuli, synchronization of potentials of the inferior parietal and frontal zones with those of the temporal increases and on presentation of objects, synchronization of potentials of the inferior parietal and occipital zones also increases. 4. Both nonspecific shifts and selective“patterns,” reflecting the specific character of the sensory system concerned, take place in the spatio-temporal organization of brain potentials during perception of sensory stimuli.