Abstract: Investigation on the genetic origin of individual differences in attention control has become increasingly popular. A majority of imaging genetics studies primarily focused on the effect of catechol-O-methyltransferase (COMT) gene on the activation of the prefrontal cortex during attention control tasks. However, neuroimaging studies have consistently demonstrated that the neural substrate of attention control comprises cortical regions not only in the prefrontal cortex but also in the parietal and cingulate cortex, which together form a neural network of attention control. In addition, these regions are also richly innervated with dopaminergic projections. Therefore, it is possible that COMT gene polymorphism modulates the activation of the parietal and cingulated cortices during attention control as well.
To examine the effect of COMT gene polymorphism, we used meta-analysis approach to re-analyze results from seventeen imaging genetics studies on the effect of COMT gene polymorphism under attention control tasks. These studies consisted of a total number of 742 participants (208 Met/Met, 315 Val/Met, and 219 Val/Val). The coordinates of peak voxels reported in the studies were projected onto a brain template to visualize the distribution of the effect of COMT gene polymorphism. Then, the effect size of COMT gene polymorphism in each region was calculated with Comprehensive Meta-Analysis program (CMA). Finally, a power analysis was performed with G*power program.
The meta-analysis indicated that Val/Val homozygotes showed higher activation not only in the prefrontal cortex but also in regions such as anterior cingulate cortex (ACC) and posterior cingulate cortex (PCC) than Met/Met homozygotes. Besides, the effect sizes of COMT gene polymorphism in these regions were above 0.8 (Cohen’s d).
In sum, the meta-analysis provides evidence that COMT gene polymorphism modulates activation in multiple cortical regions of the attention control network, suggesting that individual differences in attention control partly originate from the modulation of COMT gene polymorphism on the attention control network, not just the prefrontal cortex. Thus, our study provides clues for future COMT imaging genetics researches on attention control.

Key words: COMT gene, attention control, individual difference, imaging genetics, meta-analysis