Figure 2.

Path diagram showing the multivariate model fitted to the QSM data for seven ROIs. Squares represent observed variables, circles are latent variables. The triangle indicates that the model has a mean structure (intercepts (τ)/conditional means). Double-headed arrows attached to the same indicator variable, represent the residual variance of the indicator (δ), and those starting and ending at the same latent variable, ψ, represent the variance of the latent variable. The exogenous latent variable is denoted ξ, the factor loadings, or regression coefficients representing ξ are described by λ's. The common factors are inter-correlated by ϕ (double headed arrows). The model is identified with 58 degrees of freedom. The suffixes l and r for each of the ROI refer to the ROI in the left and right hemisphere, respectively.