Table 2.
Neuroimaging regression analyses: results of between-group comparisons.
| Region | X mm | Y mm | Z mm | # Voxels | T | p |
|---|---|---|---|---|---|---|
| Regression with STR baseline GABA+ | ||||||
| Main effect of practice | ||||||
| [Control-SCR] | ||||||
| No suprathreshold clusters | ||||||
| [SCR-Control] | ||||||
| Hippocampus | −18 | −24 | −10 | 31 | 3.13 | 0.031 |
| Modulation by speed of performance | ||||||
| No suprathreshold clusters | ||||||
| Regression with HC baseline GABA+ | ||||||
| Main effect of practice | ||||||
| [Control-SCR] | ||||||
| No suprathreshold clusters | ||||||
| [SCR-Control] | ||||||
| Hippocampus | 28 | −36 | 0 | 30 | 2.98 | 0.031 |
| Modulation by speed of performance | ||||||
| No suprathreshold clusters | ||||||
| Regression with ΔGABA+ STR | ||||||
| Main effect of practice | ||||||
| [Control-SCR] | ||||||
| Hippocampus | −20 | −14 | −20 | 79 | 3.42 | 0.015 |
| [SCR-Control] | ||||||
| No suprathreshold clusters | ||||||
| Modulation by speed of performance | ||||||
| [Control-SCR] | ||||||
| No suprathreshold clusters | ||||||
| [SCR-Control] | ||||||
| Putamen | 20 | 14 | 6 | 218 | 3.39 | 0.016 |
| (extending to caudate) | ||||||
| Regression with ΔGABA+ HC | ||||||
| No suprathreshold clusters | ||||||
Significance level set at pcorr < 0.05 corrected for multiple comparisons (FWE) over small volumes. All results survived Holm–Bonferroni correction for multiple testing. Due to missing fMRI data, one control participant was not included in the regressions with HC GABA+: N control = 23, N SCR = 22. Regressions with STR GABA+: N control = 26, N SCR = 26.
ΔGABA+ post intervention/learning minus baseline, HC hippocampus, STR striatum, SCR stress cortisol responders.