COMT val158met Genotype Affects Recruitment of Neural Mechanisms Supporting Fluid Intelligence

Abstract

Fluid intelligence (gf) influences performance across many cognitive domains. It is affected by both genetic and environmental factors. Tasks tapping gf activate a network of brain regions including the lateral prefrontal cortex (LPFC), the presupplementary motor area/anterior cingulate cortex (pre-SMA/ACC), and the intraparietal sulcus (IPS). In line with the “intermediate phenotype” approach, we assessed effects of a polymorphism (val158met) in the catechol-O-methyltransferase (COMT) gene on activity within this network and on actual task performance during spatial and verbal gf tasks. COMT regulates catecholaminergic signaling in prefrontal cortex. The val158 allele is associated with higher COMT activity than the met158 allele. Twenty-two volunteers genotyped for the COMT val158met polymorphism completed high and low gf versions of spatial and verbal problem-solving tasks. Our results showed a positive effect of COMT val allele load upon the blood oxygen level–dependent response in LPFC, pre-SMA/ACC, and IPS during high gf versus low gf task performance in both spatial and verbal domains. These results indicate an influence of the COMT val158met polymorphism upon the neural circuitry supporting gf. The behavioral effects of val allele load differed inside and outside the scanner, consistent with contextual modulation of the relation between COMT val158met genotype and gf task performance.

Complexity and compositionality in fluid intelligence

“…8, 13-15), or a more distributed network comprising regions of lateral frontal, insular, dorsomedial frontal, and parietal cortex (11,16). Performance of traditional fluid intelligence tests is associated with extensive activity within this network (17,18) (24), resembling the chaotic behavior typical of frontal lobe patients (25), especially in complex, unstructured situations (see, e.g., refs. 26 and 27).…”

Towards an understanding of neuroscience for science educators

“…A twin study investigated three components of EF: updating (WM); shifting and inhibiting EF and intelligence using Raven's Progressive Matrices (a measure of reasoning); and a Wechsler's test (a measure of intelligence in adolescence and adulthood). Updating WM showed the strongest correlation with intelligence and given its role in attention, this is perhaps unsurprising (Friedman et al, 2006), although the widespread view is that g and WM capacity are not the same entity (Bishop, Croucher, & Duncan, 2008). General intelligence, then, seems to depend on more than good WM, speed of processing and educational opportunities, but nevertheless has some strong correlates with each of these.…”

Intelligence neurocircuitry: cortical and subcortical structures

“…The mutation Val158Met gene correlates with higher activity of COMT and global reduction of dopamine in the prefrontal circuits of learning. The deficit in the fluid intelligence, activity of dorsolateral prefrontal cortex, premotor area, supplemental motor area, anterior cingulate gyrus, and intraparietal sulcus is related to less dopamine in these areas (BISHOP, FOSSELLA, CROUCHER et al, 2008).…”