3.1.2 Mechanical punctate test stimuli
Regarding the mechanical test stimuli the GLM repeated measures ANOVA analysis revealed a significant main effect of Time (F (2,16) = 4.161, p = .035, eta2 = .342). The univariate within-subject contrasts revealed that on average over both arms the VAS-score increased significantly between pre (M = 1.9) and post (1) (M = 2.5) (F (1,17) = 8.801, p = .009, eta2 = .341) and between pre and post (2) (M = 2.6) (F (1,17) = 4.753, p = .044, eta2 = .218. There is also a significant main effect of Arm (F (1,17) = 7.694, p = .013, eta2 = .312). On average over the three time points the VAS-score is different between the two arms; conditioned arm M = 2.6 and control arm M = 2.1.
More interestingly a significant
Time × Arm interaction effect (F (2,16) = 3.952,
p = .040, eta
2 = .331) was found. The univariate within-subject contrasts showed a statistically significant difference in VAS-score on post2 (versus pre) between the two arms (conditioned vs. control arm) (F (1,17) = 8.331,
p = .010, eta
2 = .329). The VAS-score observed at the conditioned arm was significantly higher (M = 3.1) than the VAS-score observed at the control arm (M = 2.1) 30 minutes after experimental conditioning stimulation (figure
3A).
Post hoc tests (paired t-tests) showed a significant increase in VAS-score of the conditioned arm between pre (M = 2.0) and post (1) (M = 2.7) (t (17) = -2,854, p = .011) and between pre (M = 2.0) and post (2) (M = 3.1) (t (17) = -2,892, p = .010). P-values are corrected for multiple comparisons using the Bonferroni correction. No significant changes in VAS-scores were observed for the control arm.