Intelligence and neural transmission time: a brain stem auditory evoked potential analysis

Brain stem auditory evoked potential (BAEP) measures were employed to assess the association of individual differences in mental ability and neural transmission time. The BAEP to brief click stimuli at 72, 80 and 88 dB intensity was recorded from 54 female participants. Overall, low positive correlations between full-scale intelligence (FIQ), as measured by the Multidimensional Aptitude Battery, and BAEP latency were observed, with salient effects at the 80 dB intensity level for wave III, wave V and interpeak latency I–V. The association of higher ability (HA) with longer BAEP latency contradicts the hypothesis of faster neural transmission for HA. Head size was also positively correlated with both mental ability and BAEP latency. An analysis using measures of head width and interpeak latency to calculate nerve conduction velocity (NCV) associated higher verbal intelligence with slower auditory NCV.