Evoked potential correlates of intelligence in nonpatient subjects

To evaluate possible influences of intelligence on evoked potential (EP) characteristics in nonpatients. EPs of age and gender matched groups (N = 19 each) of 'high', 'medium', and 'low' IQ groups were compared. EPs elicited by left and right median nerve stimulation, checkerboard pattern visual flash, and acoustic clicks were recorded from 15 scalp leads. The results confirmed previous findings showing that higher IQs are associated with higher EP amplitudes. An unexpected finding was a trend towards higher IQ/EP correlations for left than right recording sites. It appears that intelligence is an important subject variable to be controlled in any EP investigation, and furthermore that EP topography should be considered in seeking IQ/EP correlations.