Fig. 3.

Assessment of reproducibility. A) Topographical results of the mean phase difference (MPD) during slow spindles from the discovery (18 PTSD and 29 non-PTSD), replication (13 PTSD and 18 non-PTSD), and combined (31 PTSD and 47 non-PTSD) analyses. The heat maps show F-values of the statistical comparisons (Watson−Williams tests) between the PTSD and non-PTSD groups at individual channels. Black stars indicate the seed channel Fz. Black dots indicate channels with uncorrected p-values less than 0.05, whereas white dots indicate channels that were statistically significant (p < 0.05) after accounting for multiple comparisons across channels. B) Between-group differences of the MPD during slow spindles for the selected Fz–C5 channel pair in the discovery, replication, and combined analyses. The plotted values show group means, whereas the error bars indicate one standard error of the mean. Asterisks indicate levels of statistical significance for the group differences: *p < 0.05, **p < 0.01, ***p < 0.001. C) Effect sizes of group differences of the MPD during slow spindles (for the Fz–C5 channel pair) in the discovery, replication, and combined analyses. Negative values indicate that the MPD was lower in the PTSD group than in the non-PTSD group. We used Cohen’s d as the measure of effect size. Error bars indicate 95% confidence intervals (CIs) of the effect sizes; the horizontal dashed line indicates an effect size of zero. A 95% CI that does not cross zero implies that the effect is significant at the 0.05 level.