Fig. 7. Serial mediation model 2. Serial mediation analysis of dopamine 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 third serial mediation model examined whether the noradrenergic system activation can influence individual creativity by mediating cognitive flexibility under acute stress. Group (stress or control) was entered as an independent variable, the AUCi of pupil diameter (Ocular 1 to 3) and the cognitive flexibility performance changes (the post-WCST score minus pre-WCST score) were entered as potential parallel mediators, and the variations of creative task performance (changes in fluency, flexibility, and originality of the AUT ) between pre-test and post-test (post-test score minus pretest score) were entered as dependent variables. The results only showed that the stress condition enhanced the LC-NE activity (pupil dilation AUCi), which was related to decreased cognitive flexibility (the changes of WCST performance) leading to worse creative performance (originality of AUT). As we expected, the results support a serial mediation: stress was associated with NE activation, which reduced cognitive flexibility, leading to worse creative performance. Indeed, the bias-corrected bootstrap confidence interval for the indirect stress condition – NE activity – cognitive flexibility – individual creativity (parametera1 × d × b2 = 0.230) was above zero (0.034, 0.738).