Clinical neurology. Some applications of scanning by computer.

The use of averaging techniques permits a great increase in the resolution of time-locked waveforms in the electroencephologram. Averaged evoked potentials may be used to study sensory-sensory interactions and the effect of irritative and destructive lesions on the average evoked potential. More complex computations are possible once averages are derived, as was shown in the application of potential contour mapping, where considerable differences were noted between premature and newborn infants on the one hand and adults on the other. The flat, low voltage surface potential contour of the neonate was interpreted as reflecting a volume-conducted event having a distant, deep and midline source. Potential contour patterns in the adult were interpreted as showing predominantly neuronally propagated activity arising at the cortical surface.