Figure 1. The mediation model. The mediation model illustrating the direct effect of education on intellectual/social/ physical activity, the direct effect of education on TMT-B and SCWT-A performance, the direct effect of intellectual/social/ physical activity on TMT-B and SCWT-A performance and the mediating effect of intellectual/social/ physical activity on the association between educational levels and TMT-B/SCWT-A performance, as indicated by the path coefficients and the p values.