Behavioural performances and brain activation contrasts in region of interest for PTSD, combat control and healthy control groups
| Group; mean ± SD | |||||
|---|---|---|---|---|---|
| Factor | PTSD, n = 28 | Combat control, n = 26 | Healthy control, n = 25 | F statistic | p value |
| Baseline* | |||||
| Response time | 818 ± 20 | 812 ± 15 | 816 ± 15 | F = 0.83 | 0.44 |
| ROI left pre/postcentral gyrus | 0.98 ± 0.88 | 1.20 ± 1.07 | 1.06 ± 1.17 | F = 0.31 | 0.74 |
| ROI right IFG | 0.15 ± 0.96 | 0.14 ± 0.88 | −0.04 ± 1.29 | F = 0.27 | 0.77 |
| ROI right striatum | 0.05 ± 0.40 | 0.14 ± 0.39 | 0.02 ± 0.39 | F = 0.55 | 0.58 |
| Reactive inhibition† | |||||
| Stop-signal reaction time | 330 ± 15 | 325 ± 18 | 306 ± 12 | F = 16.97 | < 0.001 |
| ROI left pre/postcentral gyrus | −0.59 ± 0.74 | −1.03 ± 0.55 | −0.94 ± 0.51 | F = 3.86 | 0.025 |
| Proactive inhibition‡ | |||||
| Slope response time§ | 46.83 ± 64.31 | 85.29 ± 88.14 | 100.10 ± 73.05 | F = 3.87 | 0.025 |
| ROI right IFG§ | 4.59 ± 3.32 | 1.94 ± 4.22 | 2.87 ± 4.57 | F = 3.40 | 0.039 |
| ROI right striatum§ | 1.50 ± 1.31 | 0.68 ± 1.70 | 1.30 ± 2.50 | F = 1.16 | 0.32 |
IFG = inferior frontal gyrus; PTSD = posttraumatic stress disorder patients; ROI = region of interest; SD = standard deviation.
↵* Baseline contrast: correct go trials with a stop-signal probability of 0% versus rest.
↵† Reactive inhibition contrast: successful stop trials versus correct go trials.
↵‡ Proactive inhibition contrast: the parametric effect of stop-signal probability on go-signal activation for stop-signal probability 17% to 33%.
↵§ Baseline response time was included as a covariate (set at 815.47).