Conditioning of evoked potentials in children of differing intelligence.

This study compared the conditioning of averaged evoked potentials in three groups of children (average age 11 yrs): (I) normals, (II) IQ between 50 and 60, (III) IQ between 20 and 50. Sound was the conditioned stimulus, light the unconditioned stimulus, 68 sessions were recorded in 34 children. Decrease in the number and in the amplitude of potentials evoked by sound was observed from group I to group III, whereas generalized slow waves increased from group I to group III. Conditioning was different in the three groups. In the normal child it modified the conditioned evoked potential to sound. In the mentally retarded child, it modified generalized slow waves and brought about the reproduction of a temporal sequence.