Abstract
EEG recordings during spontaneous sleep were obtained in 50 children from 18-30 months of age (27 boys, 23 girls). Twenty five children were classified as high risk (HR) and twenty five as low risk (LR), taking into account social and cultural disadvantages. Absolute power (AP) and relative power (RP) for delta. theta, alpha and beta bands were computed. ANOVAS assesing the main effects of risk and sex as well as their interactions were performed. HR showed significantly more delta AP than LR, while LR had higher values of alpha AP than HR. Values of RP were significantly different in alpha and beta bands in Fp1, Fp2, O1 and O2. LR with more alpha and beta RP. Risk/sex interactions were only observed in delta AP in T5 and T6. Differences were more prominent in HR boys. These results suggest a maturational lag of the brain in high risk children.