Fig. 6. Serial mediation model 1. Serial mediation analysis of cortisol levels and cognitive flexibility performance on the association between stress and creative performance. The dotted line represents the non-significant path coefficients. *p< .05, ***p < .001.
The second serial mediation model examined whether stress-related dopaminergic system activation could influence creativity by mediating cognitive flexibility. Hence, the serial mediation model was tested with Group (stress or control) as the independent variables, EBR AUCi (Ocular 1 to 3) as the first mediating variable, the change in perseverative errors (the post-WCST score minus pre-WCST score) as the second mediating variable and the variations of creative task performance (changes in fluency, flexibility, and originality of the AUT) as dependent variables. The analysis indicated that the indirect effect of cognitive flexibility was significant (parametera2 × b2 = 0.492, [0.014, 1.116]), suggesting mediation by cognitive flexibility (see Figure 7). A significant effect of stress on creativity via dopaminergic system activation and cognitive flexibility was also discovered (parametera1 × d × b2 = 0.191, [0.048, 0.526]), consistent with a serial mediation through DA activity followed by cognitive flexibility.