Fig. 4.

Genetic influences on hand preference impact some of the cortical asymmetries linked to hand preference. Five clusters of handedness-associated cortical surface area asymmetry showed significant heritabilities after FDR correction (i.e., three clusters in the anterior insular cortex [clusters 2, 4, and 8], one in the fusiform cortex [cluster 1], and one in the anterior middle cingulate cortex [cluster 6]). Other handedness-associated asymmetry clusters were not significantly heritable, including the pre- and postcentral clusters of the sensorimotor cortex (clusters 7 and 10). The associations of cortical asymmetries with polygenic disposition to left-handedness are indicated, as well as individual handedness-associated genes implicated in their variabilities.