Fig. 2. Results of mediation analysis. The upper diagram represents the total model showing the group (controls vs schizophrenia) effect (τ) on antisaccade ER (anti-ER). The bottom diagram represents the mediation model with the direct group effect on antisaccade ER (τ′) and the indirect effect mediated by the antisaccade HF-HRV (α,β). ER, error rate; HF-HRV, high frequency component of heart rate variability.