Characterization of developmental changes in EEG-gamma band activity during childhood using the autoregressive model.

BACKGROUND

We characterized developmental changes in the EEG-gamma band during childhood using the autoregressive (AR) model, which was previously developed and described in our laboratory.

METHODS

The subjects comprised 707 healthy children ranging in age from 3 to 12 years. Electroencephalographs (EEG) were recorded from Fp1, Fp2, C3, C4, O1 and O2, monopolar leads referenced to the ear during quiet wakefulness (eyes closed). One 10 s artifact-free segment was selected from each record, digitized, then analyzed by AR and component analysis, which estimated the component wave and power spectrum.

RESULTS

Component waves obtained from all EEG leads were divided into eight groups, which comprised approximately 2, 5, 10, 17, 25, 30, 40 and 47 Hz peaks. The gamma band (peak wave 40 Hz; range 35-45 Hz) was a major EEG component throughout childhood. Different developmental characteristics of the gamma band power were exhibited in each lead. The power increased significantly (P < 0.01) between 3 and 4 years of age in all leads reaching a peak at 4-5 years of age, especially in the frontal region.

CONCLUSIONS

These developmental characteristics might be related to the information processing and cognitive function, which is enhanced at 4-5 years of age, especially in the frontal region.