Algorithm 1.

Modulation of voxel values for an ROI r.

Let a(r) be the association model assigned for ROI r in Table I and l(r) be the corresponding SNP locus Let GT(s, l(r)) be the genotype of subject s at SNP locus l(r) for each subject s do Calculate PT(s, r), the phenotype group of its ROI r, using GT(s, l(r)), a(r) and Table II Let m be the total number of subjects whose ROI r's are in phenotype group P+, i.e., m = |{s|PT(s, r) = P+}| Let n be the total number of subjects whose ROI r's are in phenotype group P−, i.e., n = |{s|PT(s,r) = P−}| Let f(x) be the modulation function defined in Fig. 5. for each voxel x in the ROI r of each subject s do Let Iorig(x) be the original voxel value if PT(s, r) = P+ then $I_{\mathit{new}}\left(x\right)=I_{\mathit{orig}}\left(x\right)\ast (1+\frac{n}{m}\ast f\left(x\right))$ else if PT(s, r) = P− then Inew(x) = Iorig(x) * (1 − f(x)) Let Inew(x) be the new voxel value after modulation