Noting the degree of heterogeneity between SNPs apparent in the association trajectories, and the apparent correspondences in significance of the association trajectories within the SNPs (see figure 3), a test of the null hypothesis that degree of within SNP correspondence could be the effect of a random occurrences of the significant SNP-phenotype association instances was undertaken. To be more specific, the within-SNP correspondences are between different scalp locations in the same modality, and between the different modalities at the same scalp location, where correspondence is based on simultaneous significance or non-significance of the coarse-grained p-values based on the threshold determined by controlling the false discovery rate at 5% for the median p-values. The measure for correspondence between scalp locations is the sum of number of significant values for the three scalp locations for each age-SNP-modality combination and for the correspondence between modalities is the sum of number of significant values for the two modalities for each age-SNP-scalp location combination. Permutation tests are applied to the null hypothesis that random permutation of SNP-phenotype association instances, preserving either the scalp locations for
