Figure 16: UKB neuroimaging data: Spatial maps of group-specific reconstructed data from MSIVA ${\mathit{S}}_2$ sources related to age and sex effects.

Axial slices show the geometric median of the reconstructed data (${\widehat{\mathbf{\text{X}}}}_k^{\left[m\right]}$) for each modality (sMRI or fMRI) and each group (younger: 46 – 63 years, older: 63 – 79 years; male or female). Voxel intensity is mapped to both color hue and opacity. The contours highlight the brain areas where voxelwise cross-modal correlations are significant for each group ($P<0.01$, Bonferroni correction for 44318 voxels). Scatter plots show post-CCA sources color-coded by age or sex. The reported $R^2$ indicates the proportion of variance captured by the subspace in each modality.