Computer tomography in children with electrophysiological abnormalities

EEG and behavioral changes following neurofeedback treatment in learning disabled children

Neurofeedback (NFB) is an operant conditioning procedure, by which the subject learns to control his/her EEG activity. On one hand, Learning Disabled (LD) children have higher values of theta EEG absolute and relative power than normal children, and on the other hand, it has been shown that minimum alpha absolute power is necessary for adequate performance. Ten LD children were selected with higher than normal ratios of theta to alpha absolute power (theta/alpha). The Test Of Variables of Attention (TOVA) was applied. Children were divided into two groups in order to maintain similar IQ values, TOVA values, socioeconomical status, and gender for each group. In the experimental group, NFB was applied in the region with highest ratio, triggering a sound each time the ratio fell below a threshold value. Noncontingent reinforcement was given to the other group. Twenty half-hour sessions were applied, at a rate of 2 per week. At the end of the 20 sessions, TOVA, WISC and EEG were obtained. There was significant improvement in WISC performance in the experimental group that was not observed in the control group. EEG absolute power decreased in delta, theta, alpha and beta bands in the experimental group. Control children only showed a decrease in relative power in the delta band. All changes observed in the experimental group and not observed in the control group indicate better cognitive performance and the presence of greater EEG maturation in the experimental group, which suggests that changes were due not only to development but also to NFB treatment.

Poverty, cultural disadvantage and brain development: a study of pre-school children in Mexico

Forty-two children, who had been studied previously at the age of 18-30 months, were studied again at 4 years of age. Twenty-two belonged to low socioeconomic strata and were classified as high-risk children (HRC) the other 20 were classified as low-risk children (LRC), and belonged to middle and middle-high socioeconomic strata. Ten minutes of EEG using reference derivations (with linked earlobes) were recorded from each subject. Twenty EEG segments of 3.2 s each were selected by visual inspection for Fourier analysis. Absolute power (AP) was computed for the total EEG energy (1.5-19 Hz) as well as each reference derivation in 4 frequency bands: delta (1.5-3.5 Hz), theta (4-7.5 Hz), alpha (7.5-12.5 Hz) and beta (12.5-19 Hz). HRC had significantly more delta AP than LRC in frontal and central leads, and higher values of theta AP in frontal leads. Alpha AP was higher in LRC in occipital areas and in F8 and T4. This study suggests a maturational lag in HRC.