Polygenic burden was also associated with greater bilateral amygdala and left rostral ACC Participation Coefficient, suggesting that these regions are more likely to serve as ‘connector hubs’ as genetic risk increases. Connector hubs provide ‘shortcuts’ to communicate between segregated modules, and such module segregation is necessary for a network to perform multiple types of specialized processes. Thus, our findings suggest that amygdala and rACC influence a wider range of specialized processes as externalizing polygenic scores increase. This may lead to greater influence of amygdala on, not only bilateral IFG as the resting-state connectivity analyses suggested, but on a diverse range of processes. These findings extend previous work on externalizing by suggesting that abnormalities in neural network organization may be a heritable mechanism by which genetic risk for externalizing is conferred.
