Fig. 2.

Path Diagram of the Structural Equation Model Describing the Relation of Neuregulin-1 (NRG1) and Smooth Eye Pursuit Global Performance Variables. The exogenous manifest variables (squares) were the rare allele loads of the additive model for each SNP. These variables loaded (arrows) on one exogenous latent variable (ellipse) named “NRG1.” The endogenous manifest variables (squares), namely, the smooth pursuit root-mean-square error (RMSE) and saccade frequency (sac freq) variables for the 3 pursuit speeds (10°/s, 20°/s, and 30°/s) also loaded (arrows) on 2 latent endogenous variables (ellipses) named “RMSE” and “sac freq.” Finally, the exogenous latent variable “NRG1” loaded (arrows) on the 2 endogenous latent variables “RMSE” and “sac freq.” The model also included residual variables for all exogenous manifest variables (depicted as δ 1–5), residual variables for all endogenous manifest variables (depicted as ϵ 1–7,) and disturbances for all endogenous latent variables (depicted as ζ 1 and 2) that all loaded on their respective variable (small elliptic lines). Solid arrows indicate significant factor estimates, while dotted arrows indicate nonsignificant factor estimates at the level of P = .05. The factor loading estimates and their respective P values (in parentheses) are depicted with a number on the line.