Conditions for correlation between IQ and auditory evoked potential latencies

In this work we studied the relationship between IQ scores on the Wechsler Intelligence Scale for Children (WISC) and the latencies of Brainstem AEPs (BAEPs; AEP = Auditory Evoked Potential), Middle-latency AEPs (MAEPs) and Long-latency AEPs (LAEPs) in 28 healthy subjects aged 9–15 years (mean WISC full-scale IQ 96); LAEPs were elicited in both passive and active oddball experiments. The only significant correlation found was between IQ and P300 latency in active oddball experiments. We suggest that AEP latency only correlates with IQ for waves generated after the auditory information has reached the associative cortex, and perhaps even then only if the subject is performing a task involving controlled attention and the updating, following stimulus evaluation, of the representation of stimulational context in working memory. Under these conditions, the subjects with the highest IQs in this study were the fastest in processing auditory information.