SNP heritability estimates are presented in Table 3. Values are provided for each threshold of genetic relatedness used to create subsamples of unrelated individuals, and are based on unweighted SNPs as well as SNPs that had been weighted SNPs by local LD patterns to attenuate the effects on SNP heritability estimates of high levels of LD with causal SNPs. Because estimates are based on unrelated individuals, standard errors are quite large. Our interest is in patterns in the point estimates. As expected, the weighted estimates tend to have smaller point estimates and larger SEs, both of which are arguably appropriate (Speed et al., 2012). The occipital-parietal measures of alpha power and peak frequency produced median point estimates of .45 and .48, respectively, across the two methods and three thresholds of genetic relatedness, which were consistently larger than the Cz estimates, including the estimate for alpha power at Cz. SNP heritability estimates for alpha and beta power at Cz were relatively modest, with median values of approximately .20. Estimates for the other parameters tended to be quite small, although those for delta varied somewhat across thresholds and methods.
