An irrelevant auditory probe procedure was employed to evoke brain event-related potentials (ERPs) in 56 right-handed Caucasian males while they learned concepts presented to them in study booklets. A mastery test was administered to assess concept acquisition. Subjects were divided into two groups according to whether or not their achievement test results were above or below the average score for all learners. A one-way multivariate analysis of variance (MANOVA) was computed for each presentation page employing as multiple dependent measures ERP amplitudes which corresponded to specific concepts. MANOVAs and their subsequent statistics revealed that, as theorized, ERPs evoked at the right frontal, temporal, and parietal, as well as the left parietal, regions, significantly distinquished below- from above-average concept learners. As hypothesized, poorer concept learners engaged these hemispheric sites less, and manifested more variability at them, than better learners. It was established that the frontal, temporal, and parietal areas, which are mainly implicated in crystalized intelligence, are engaged during the actual process of concept learning. (Author/DWH)