The hyperkinetic child: a behavioural, electrodermal and EEG investigation.

Ten hyperkinetic children were compared with a matched group of normal controls on the basis of behavioural measurements, electrodermal recordings and spectral analysis of the EEG. All the behavioural measures (total motor activity, speed of movement, and noisiness) differentiated the two groups in the predicted directions. The groups did not differ significantly in respect of the skin admittance (a.c. conductance) level or the EEG alpha rhythm propagation time. These findings provide no support for the hypothesis that hyperkinetic children are under-aroused. The best differentiation between the groups was provided by the EEG coherence function. The hyperkinetic group showed a significantly higher coherence within the hemisphere than the controls at frequencies up to 8Hz. It is speculated that they may reflect diminised cortical processing of information in the patients by comparison with the controls.