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).