Figure 4. Latent space encoding of whole-brain functional connectivity (FC) reflects the different neurodegenerative diseases and the severity of Alzheimer’s disease (AD) in terms of white-matter hyperintensity (WHMI) scores.

(A) Original (above diagonal) and reconstructed (below diagonal) FC matrices. (B) Illustration of the FC matrix encoded at each point of the latent space by the variational autoencoder (VAE). (C) Latent space encoding of 300 independent runs of the model fitted to empirical CNT, AD-, AD+, and behavioral variant frontotemporal dementia (bvFTD) data. The larger circles represent the average of the positioning of all encoded points for each group. (D) Distribution of distances (D) to CNT for each condition (*indicates $\left|\mathrm{d}\right|$ >0.8 between distributions).