Event-related potential (ERP) correlates of performance of intelligence tests.

Any relationship between measures of cognitive function and brain electrical activity would be of considerable importance in the objective assessment of patients suspected of intellectual impairment. In healthy subjects, we have found a strong correlation between the event-related potentials evoked by a digit probe identification task and scores on intelligence tests (WAIS). Responses from subjects with higher performance on IQ tests are significantly 'more negative' than those from subjects with lower IQ. The characteristics of these IQ-dependent electrophysiological features suggest that they may be related to the subject's ability to focus on a task.