Figure 1.

A latent change score model for the assessment of two-occasion changes in episodic memory (EM). Squares represent observed variables, circles are latent variables. The triangle indicates that the model contains means. Free parameters are marked by an asterisk. Parameters with equal sign and the same subscript are constrained to be equal to each other. Change is modeled in a second order latent variable (EM), reflected by two subordinated latent variables: recall and recognition. Notations: δ = mean at baseline; α = variance at baseline; β = mean change, γ = variance in change; ε = covariance between individual differences in EM at baseline and individual differences in changes between baseline and follow-up. The model contains eight observed variables and nine free parameters, with 21 degrees of freedom.