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. Author manuscript; available in PMC: 2014 Feb 16.
Published in final edited form as: Neuroimage. 2013 Oct 12;86:392–403. doi: 10.1016/j.neuroimage.2013.10.006

Fig. 1.

Fig. 1

N-back task-related group cerebellar activation (A), test–retest reliability (B), twin correlations (C), and variance component estimates for n-back task-related cerebellar activation (D). (A) Group random effects analysis for the 2-back > 0-back t-contrast (p<0.05, FWE-corrected); (B) intra-class correlations and corresponding height- (p <0.05) and cluster- (>540 voxels) thresholded p-values for the group activation; (C) intra-pair MZ and DZ twin correlations; (D) percentage of variance explained by genetic (a2) and unique environmental factors (e2) factors and probability map for a2, indicating which genetic estimates were significant after height- (p <0.05) and cluster- (>540 voxels) thresholding. Twin correlations and variance component estimates were estimated using maximum likelihood procedures and corrected for sex, age, 2-back performance accuracy and RT. Green, yellow, and red areas are those with the highest twin correlations and heritability. Assumption testing supported homogeneity of means across birth order for ~86% of voxels, homogeneity of variances across birth order for 100% of voxels, homogeneity of means across zygosity for ~90% of voxels and homogeneity of variances across zygosity for ~96% of voxels. There were no significant mean or variance differences between twins and siblings. Therefore, sibling pairs were included in the DZ group.