In studying the chronology of myelinogenesis, it was suggested that though sensory and motor brain systems generally complete their myelination before the ...
In/em. J. Neuroscience, 1994, Vol. 75, pp. 257-270 Reprints available directly from the publisher Photocopying permitted by license only
© 1994 Gordon and Breach Science Publishers S.A.
Printed in the UnitedStates of Arnerica
EEG RHYTHMICITIES EVOKED BY VISUAL STIMULI IN THREE- YEAR-OLD CHILDREN VASIL KOLEV Brain Research Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev str., bl. 23, 1113 Sofia, Bulgaria CANAN BAŞAR-EROGLU Institute of Physiology, Medical University Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany co o o N
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FUAT AKSU Yestische Kinderklinik, Department of Neuropediatrics,
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EROL BAŞAR Institute of Physiology, Medical University Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
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(Received July 13, 1993)
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The present paper complements our investigations on children/s and adult''s EEGs and evoked potentials elicited by mean of auditory stimulation. We analyzed the spectral characteristics of spontaneously recorded EEGs, visual evoked potentials, and frequency responses of a group of 3-year-old children. The results were compared to the corresponding rneasurements in adults aged 20-22 years. Dur findings show that: ı. the main frequency YEP components in 3 years old children are "delta" and "theta responses" with delayed time courses in comparison to adult's VEPs, 2. the existence of a given frequency component in the VEPs depends on the presence of the corresponding rhythm in the spontaneous EEG, and 3. the individual filtered children's VEPs show larger variability in comparison to adults, as well as different interhemispheric variability in the different frequency ranges. It was concluded that the evoked frequency components depend on the frequency content of the spontaneous EEG rhythms and the ir development. However, some of the children already showed alpha enhaneement as well as synchronized alpha waves in the poststimulus period at the occipital and parietal leads. The possible explanation of these phenomena might be referred to early development of the posterior basic rhythms as well as to known resonance phenomena such as weak resonance and tuning.
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