Separate contributions of general intelligence and right prefrontal neurocognitive functions to academic achievement at university level

It is hypothesized that performance on frontal-lobe neuropsychological tests and intelligence tests may independently contribute to variation in academic achievement in higher education. We examined the ability of an IQ test (the WAIS-IV) to predict grade point averages (GPA) in a sample of 64 undergraduate students. We also included a battery of five neuropsychological assessments of frontal-lobe functions, all known to be unrelated to general intelligence and linked to right-prefrontal function. Regression analysis with stepwise entry of variables revealed separate contributions to the variation in GPA scores explained by general intelligence and two different measures of response inhibition (Stop-signal and Hayling). The addition of the inhibition measures more than doubled the amount of variance in GPA explained by general intelligence alone, from adjusted R²=.115 to adjusted R²=.239, suggesting an important role of right prefrontal-mediated response inhibition in high-level academic achievement. This contrasts with the mainly left-hemisphere contribution from general intelligence.