Auditory nerve, brainstem and cortical response correlates of learning capacity

An attempt has been made in this study to determine whether auditory nerve, brainstem (ABR) and cortical auditory evoked responses differ between various groups defined with respect to their intellectual ability. Seventy-seven (77) children, male and female in the same age range were divided according to learning ability and IQ scores into three groups: border-line retardates (R), normals (N) and gifted (G). These groups also demonstrated differences in behavioral tests: draw a person test, reaction-time test, audio-visual integration test and audio-visual cross-modality test. The "R Group" performed behaviorally at the lowest level and the "G Group" performed at the same or at a somewhat higher level than the "N Group". Analysis of variance for the latency and amplitude parameters of the brainstem (ABR) and cortical auditory averaged evoked responses among the behaviorally defined groups showed that the main differences were in the amplitude parameters, reaching significance in the ABR response. Latency differences among the groups were identical in the ABR responses and did not reach significance in the cortical response. Rate functions did not expose other differences between the groups. Many of these electrophysiological measures were correlated with the behavioral measures.