Figure 2: Overview of three proposed initialization workflows.

The initialization approaches from left to right are separate PCAs followed by separate ICAs (PCA + ICA); multimodal group PCA with separate ICAs per modality (MGPCA + ICA); multimodal group PCA with group ICA (MGPCA + GICA). The MGPCA + ICA initialization workflow is denoted as MSIVA. After initialization, the combinatorial optimization and numerical optimization with the MISA loss were performed for sufficient iterations until the loss value converged.