Heterogeneous results among neuro-imaging studies using psychometric intelligence measures may result from the variety of tests used. The g-factor may provide a common metric across studies. Here we derived a g-factor from a battery of eight cognitive tests completed by 6929 young adults, 40 of whom also completed structural MRI scans. Regional…

It is unclear whether brain mechanisms underlying human intelligence are distributed throughout the brain or mainly concentrated in the frontal lobes. Data are inconsistent possibly due, at least in part, to the different ways the construct of intelligence is measured. Here we apply the method of correlated vectors to determine how the general…

Choice reaction time and simple reaction time were measured for 147 young adults for whom significant positive correlation between nerve conduction velocity in a brain nerve pathway and nonverbal intelligence was previously found. Results suggest that two largely independent neurophysiological processes affect intelligence. Differences in choice…