Table 2.
Clusters showing significant fractional anisotropy (FA) and mean diffusivity (MD) difference between marijuana+alcohol users and controls
| Anatomic region | Cluster Size (voxels) |
MNI Coordinate* | Effect Size (Cohen's d)† |
Group Difference |
||
|---|---|---|---|---|---|---|
| x | y | z | ||||
| FA | ||||||
| Superior longitudinal fasciculus L | 212 | 33.2 | 42.4 | 33.5 | 0.75 | MJ+ALC < CT |
| Crus cerebri L | 152 | 13.9 | 18.0 | -13.2 | 0.72 | MJ+ALC < CT |
| Postcentral gyrus L | 109 | 22.8 | 34.3 | 57.8 | 0.89 | MJ+ALC < CT |
| Occipital-cuneus R | 95 | -17.5 | 86.3 | 16.2 | -1.00 | MJ+ALC > CT |
| Inferior longitudinal fasciculus R | 91 | -40.7 | 36.0 | -8.5 | 0.54 | MJ+ALC < CT |
| Superior longitudinal fasciculus (arcuate) R | 83 | -39.7 | -11.3 | 16.8 | -0.57 | MJ+ALC > CT |
| Superior temporal gyrus R | 80 | -37.6 | 8.7 | -15.7 | 0.69 | MJ+ALC < CT |
| Crus cerebri R | 80 | -15.1 | 18.0 | -12.4 | 0.83 | MJ+ALC < CT |
| Anterior limb internal capsule R | 74 | -18.2 | -15.7 | 3.1 | -0.50 | MJ+ALC > CT |
| Corpus callosum (splenium) R | 71 | -17.4 | 44.6 | 13.5 | 0.55 | MJ+ALC < CT |
| Inferior frontal gyrus (opercular/insular) R | 66 | -40.0 | -4.2 | 21.9 | 0.56 | MJ+ALC < CT |
| Temporo-thalamic tract L | 63 | 19.4 | 24.1 | -0.8 | 0.58 | MJ+ALC < CT |
| Occipto-frontal tract L | 60 | 27.1 | 2.2 | 21.4 | 0.48 | MJ+ALC < CT |
| MD | ||||||
| Inferior longitudinal fasciculus L | 57 | 49.2 | 41.3 | -5.9 | 0.57 | MJ+ALC < CT |
| Occipital-lingual R | 54 | -15.1 | 88.3 | 0.5 | -0.66 | MJ+ALC > CT |
*
Coordinates of the center of mass in significant clusters
†
Effect size from the average t-value for each cluster
L=Left; R=Right; MJ+ALC=marijuana+alcohol user; CT=Control