Table 2.
Age Group Interactions of Associations Between Sleepiness (KSS Scores) and GM Volume
| Region of Interest (ROI) | Age Effect | MNI (x, y, z) | Z | Voxels (mm3) | PFWE |
|---|---|---|---|---|---|
| L insula | Interaction Y+ O– | –34, 8, –15 | 4.02 | 6605 | 0.015 |
| R insula | Interaction Y+ O– | 32, 9, –18 | 4.42 | 5947 | 0.009 |
| L Sup OFC/rectus gyrus | Interaction Y+ O– | –10, 20, –14 | 2.16 | ∞ | 0.895 |
| R Sup OFC/rectus gyrus | Interaction Y+ O– | 8, 21, –20 | 2.18 | 2271 | 0.884 |
| L hippocampus | Interaction Y+ O– | –24, –22, –16 | 3.12 | 2457 | 0.149 |
| R hippocampus | Interaction Y+ O– | 15, –32, 9 | 3.17 | 2977 | 0.131 |
| L thalamus | Interaction Y+ O– | –15, –22, 2 | 3.75 | 3068 | 0.020 |
| R thalamus | Interaction Y+ O– | 20, –26, 4 | 4.60 | 4074 | 0.001 |
Notes: Y+ indicates a positive association in younger adults, and O– indicatesnegative association in older adults. ∞Effects seen in left and right hemisphere belongs to the same cluster of GM volume; bold= significant p-values. x, y, z = coordinates.
Abbreviations: GM, gray matter; MNI, Montreal Neurological Institute; L, left; R, right; Sup OFC, frontal superior orbitofrontal cortex; FWE, family wise-error correction; KSS, Karolinska Sleepiness Scale.