**Figure 1.** **Fitted and observed trajectories of jointly modelled episodic memory and B-SIT scores.** Scales are z-scores (mean 0, SD 1). (**A**) The trajectories of the entire sample (*n*= 1023; (**B**) Latent Class 1-Stable average (*n*= 690, 67.4%); (**C**) Latent Class 2- Stable EM/OI decline (*n*= 231, 22.6%); (**D**) Latent Class 3- Joint decline (*n*= 102, 10.0%). The mean trajectories of each plot are shown in bold.