3.2. Psychological stress parameters
The effects of the stress induction on STAI-S score, negative affect
scores and positive affect scores were analyzed by mixed-measures
ANOVAs, with the factors Time (S1 to S5 time points) and Group (control
group vs. stress group).
For the STAI-S scores (see Figure 3A), the results showed significant
main effects of Group, F (1, 61) = 13.179, p <
.001, \(\eta_{p}^{2}\) = 0.18, and Time, F (4, 244) = 10.34,p < .001, \(\eta_{p}^{2}\) = 0.15 (see Figure 3A). The
interaction of Time × Group was also significant, F (4, 244) =
6.83, p < .001, \(\eta_{p}^{2}\) = 0.10. Simple effect
tests (Bonferroni corrected) showed that the control groups had
significantly lower STAI-S scores than the stress group at the time
points of S3 (p < .001), S4 (p = .010), and S5
(p < .001).