Table 2. Areas displaying significant correlations between white matter microstructure measurements and age.
| Tracts | Cluster size (N voxels) | T value | P-value (TFCE corrected) |
Coordinates of the peak in aligned anatomical space |
||
|---|---|---|---|---|---|---|
| X | Y | Z | ||||
| Positive correlation between fractional anisotropy and age in typically developing individuals | ||||||
| Superior longitudinal fasciculus R External capsule R Corpus callosum (forceps minor, body, splenium, tapetum, forceps major) Inferior fronto-occipital fasciculus R Inferior longitudinal fasciculus R Corona radiata (anterior, superior and posterior part) R Internal capsule (anterior and posterior limb, retrolenticular part) R Thalamic radiation (anterior and posterior part) R Fornix R | 15 032 | 2.66 | 0.021 | 42 | −13 | −14 |
| Inferior longitudinal fasciculus L Corticospinal tract L Thalamic radiation (anterior and posterior part) L Medial lemniscus L Inferior fronto-occipital fasciculus L Superior longitudinal fasciculus L Cingulum (cingulate gyrus and hippocampus) L Posterior corona radiata L | 2033 | 3.63 | 0.026 | −24 | −71 | 26 |
| Corticospinal tract R Anterior thalamic radiation R | 1628 | 3.22 | 0.039 | 9 | −29 | −19 |
| Cingulum in hippocampus R Inferior longitudinal fasciculus R | 1102 | 3.84 | 0.034 | 30 | −20 | −28 |
| Uncinate fasciculus R Inferior fronto-occipital fasciculus R | 241 | 3.69 | 0.042 | 28 | 14 | −9 |
| Cerebellum (peduncles and pons) | 98 | 3.94 | 0.046 | 11 | −75 | −33 |
| Anterior thalamic radiation R Medial lemniscus R | 80 | 3.46 | 0.048 | 8 | −20 | −8 |
| Inferior longitudinal fasciculus L | 72 | 3.76 | 0.046 | −34 | −57 | −12 |
| Forceps major Inferior fronto-occipital fasciculus R | 66 | 2.89 | 0.047 | 24 | −87 | 23 |
| Inferior fronto-occipital fasciculus R | 21 | 2.79 | 0.049 | 28 | 48 | −6 |
| Middle cerebellar peduncle | 12 | 3.37 | 0.049 | 14 | −29 | −37 |
| Inferior longitudinal fasciculus L | 4 | 3.53 | 0.049 | −34 | −48 | −14 |
| Negative correlations between mean diffusivity and age in typically developing individuals | ||||||
| Corpus callosum (forceps minor, genu, body, splenium, tapetum, forceps major) Superior longitudinal fasciculus R+L Cerebellum (peduncles and pons) Corona radiata (anterior, superior and posterior part) R+L Inferior fronto-occipital fasciculus R+L Internal capsule (anterior and posterior limb, retrolenticular part) L+R Inferior longitudinal fasciculus R+L Corticospinal tract R+L Thalamic radiation (anterior and posterior part) R+L External capsule R+L Cingulum (cingulate gyrus and hippocampus) R+L Uncinate fasciculus L+R Medial lemniscus R+L Fornix L+R | 79 764 | 2.12 | <0.001 | 16 | −79 | 22 |
| Negative correlation between mean diffusivity and age: ASC < typically developing individuals | ||||||
| Superior longitudinal fasciculus R Corona radiata (anterior, superior and posterior part) R Corpus callosum (forceps minor, genu, body, splenium, tapetum, forceps major) Inferior fronto-occipital fasciculus R External capsule R Inferior longitudinal fasciculus R Thalamic radiation (anterior and posterior part) R Internal capsule (anterior and posterior limb, retrolenticular part) R Corticospinal tract R Cingulum (cingulate gyrus and hippocampus) R Uncinate fasciculus R Fornix R | 20 963 | 3.38 | 0.011 | 20 | −74 | 37 |
| Negative correlation between second diffusivity direction and age: ASC < typically developing individuals | ||||||
| Superior longitudinal fasciculus R Corona radiata (anterior, superior and posterior part) R Corpus callosum (forceps minor, genu, body, splenium, tapetum, forceps major) Corticospinal tract R Thalamic radiation (anterior and posterior part) R Inferior fronto-occipital fasciculus R Internal capsule (anterior and posterior limb, retrolenticular part) R External capsule R Inferior longitudinal fasciculus R Cingulum (cingulate gyrus and hippocampus) R Uncinate fasciculus R Fornix R | 14 391 | 2.82 | 0.017 | 50 | 0 | 18 |
| Corpus callosum (splenium and forceps major) | 4924 | 3.68 | 0.031 | −20 | −49 | 22 |
| Anterior thalamic radiation L | 4489 | 3.24 | 0.037 | −6 | −4 | 8 |
| Forceps minor Anterior thalamic radiation R | 3835 | 3.98 | 0.029 | 20 | 37 | 19 |
| Uncinate fasciculus L Inferior fronto-occipital fasciculus L Anterior thalamic radiation L | 1622 | 3.24 | 0.038 | −39 | 38 | 6 |
| Inferior longitudinal fasciculus L Uncinate fasciculus L Superior longitudinal fasciculus L | 807 | 3.63 | 0.04 | −44 | 3 | −21 |
| Superior longitudinal fasciculus L | 770 | 3.87 | 0.047 | −39 | 6 | 42 |
| Inferior longitudinal fasciculus L Inferior fronto-occipital fasciculus L Superior longitudinal fasciculus L | 406 | 2.45 | 0.047 | −42 | −17 | −17 |
| Forceps minor Cingulate gyrus Anterior corona radiata L | 275 | 2.57 | 0.047 | −17 | 33 | 14 |
| Corticospinal tract L | 249 | 3.98 | 0.043 | −19 | −31 | 48 |
| Inferior longitudinal fasciculus L | 232 | 3.03 | 0.048 | −34 | −54 | −13 |
| Middle cerebellar peduncle | 128 | 3.18 | 0.048 | 24 | −65 | −37 |
| Inferior fronto-occipital fasciculus L Inferior longitudinal fasciculus L Forceps major | 94 | 2.3 | 0.048 | −26 | −72 | 0 |
| Inferior longitudinal fasciculus L Uncinate fasciculus L | 91 | 2.68 | 0.049 | −40 | −3 | −24 |
| Corticospinal tract L | 81 | 2.88 | 0.048 | −9 | −29 | 60 |
| Uncinate fasciculus L | 61 | 3.08 | 0.049 | −26 | 22 | −17 |
| Negative correlation between second diffusivity direction and age: ASC < siblings | ||||||
| Superior longitudinal fasciculus R | 77 | 2.68 | 0.041 | 47 | −3 | 24 |
| Superior longitudinal fasciculus R | 47 | 2.84 | 0.047 | 34 | −2 | 29 |
| Negative correlation between third diffusivity direction and age: ASC < typically developing individuals | ||||||
| Superior longitudinal fasciculus R | 68 | 4 | 0.046 | 53 | −33 | 36 |
| Superior longitudinal fasciculus R | 67 | 3.85 | 0.047 | 42 | −28 | 37 |
Abbreviations: ASC, autism spectrum condition; L, left; R, right; TFCE, threshold-free cluster enhancement.