Article Figures & Data
Figures
- Fig 1.
Overlay of skeletonized averaged FA map (orange) onto standardized FA map from DTIs.
- Fig 2.
Group difference map for control subjects greater than dyslexic subjects for skeletonized diffusion FA using TBSS software. The crosshair is positioned on a significant cluster near the right inferior frontal gyrus. Orange-red areas show significant clusters for group difference.
Tables
- Table 1:
Means, SDs, and values of t comparing means on psychological measures for control subjects and adults with dyslexia
Measure Control Dyslexia Mean SD Mean SD t Word Identification‡ 106.14 6.47 94.43 13.29 2.19* Word Attack‡ 105.29 5.02 91.14 12.43 2.87† Real Word Reading 101.71 11.60 85.07 9.95 3.42† Pseudo Word Reading 94.43 18.17 77.07 9.49 2.91† GORT 3 Reading Accuracy§ 14.86 2.61 9.00 4.61 3.10† GORT 3 Reading Rate§ 14.00 2.24 9.00 3.26 3.63† WRAT 3 Spelling‡ 103.29 9.20 86.14 13.97 2.92† WIAT II Spelling‡ 113.00 12.38 94.85 13.04 3.02† Non Word Memory‖ 1.09 0.88 0.70 0.67 1.13 RAN Letter‖ −0.14 0.80 1.60 1.43 −2.97† RAS Letter/Number‖ 0.10 1.00 2.41 1.51 −3.66† Note:—WRMT-R word attack indicates the rate of pronouncing pseudowords on a list, Woodcock Reading Mastery Test-Revised; TOWRE sight word efficiency, rate of pronouncing single words on a list, Test of Word Reading Efficiency; TOWRE phonemic decoding efficiency, rate of pronouncing pseudowords on a list, Test of Word Reading Efficiency; GORT 3 accuracy, accuracy of pronouncing words during oral reading of text, Gray Oral Reading Test; GORT 3 rate, rate of pronouncing words during oral reading of text, Gray Oral Reading Test; WRAT 3 spelling and WIAT II spelling, written spelling of dictated words; nonword memory, oral reproduction of aurally presented pseudowords; RAN letter, rate of pronouncing randomly presented letters in rows; RAN letter and number, rate of pronouncing switching letters and numbers presented in rows.
* P < .05.
† P < .01.
‡ Scores on a scale of mean = 100; SD = 15.
§ Scores on a scale of mean = 10; SD = 3.
‖ Z-scores on a scale of mean = 0; SD = 1.
- Table 2:
White matter regions within the boundaries of the AAL* atlas where control subjects were significantly greater than dyslexic subjects in the skeletonized fractional anisotropy
Brain Region t Statistic No. of Voxels MNI Coordinates† Brodmann Area Stanberry Comparison x y z Precentral L 2.55 42 −35 −7 38 6 No Precentral R 2.94 88 52 0 21 6 No Frontal Sup R 2.97 54 19 55 17 10 Yes Frontal Mid R 2.81 45 36 36 17 46 Yes Frontal Inf Oper R 2.80 86 55 19 0 44 Yes Frontal Inf Tri R 2.80 38 38 43 1 45 Yes Frontal Inf Orb L 3.02 60 −47 38 −12 47 No Frontal Inf Orb R 2.74 91 51 36 −8 47 No Supp Motor Area R 2.95 44 14 3 61 6 No Cuneus R 2.89 59 9 −94 12 18 No Lingual L 2.84 49 −10 −89 −17 18 No Occipital Sup L 2.77 31 −20 −90 18 18 No Occipital Sup R 2.78 36 26 −76 26 7 No Occipital Mid R 2.92 51 42 −77 18 7 Yes Fusiform L 2.90 21 −20 −84 −19 18 Yes Fusiform R 2.76 81 41 −11 −32 20 Yes Postcentral L 3.12 26 −52 −19 30 48 No Postcentral R 2.53 27 53 −1 22 3 No Parietal Sup L 3.10 42 −14 −72 47 5 No Parietal Inf L 2.68 28 −30 −43 45 40 No Parietal Inf R 3.31 41 47 −47 40 40 Yes Precuneus L 2.76 16 −10 −72 48 7 No Putamen L 2.84 32 −17 11 2 0 No Temporal Sup L 2.69 48 −48 −33 8 22 No Temporal Pole Sup L 2.88 32 −23 15 −31 38 No Temporal Mid L 3.08 69 −47 −34 8 39 No Temporal Inf L 2.79 104 −60 −54 −19 37 Yes Temporal Inf R 2.57 27 41 −9 −33 20 Yes Note:—The last column shows the regions where both the current study and Stanberry et al8 functional connectivity study have consistency; Sup, superior; Inf, inferior; Orb, orbital; Supp, supplementary; Oper, operculum; L, left; R, right.
* AAL refers to the Automated Anatomical Labeling map which is a 3-dimensional map containing 116 brain regions co-registered to standard MNI space.
† MNI coordinates refers to a standard brain imaging coordinate system developed by the Montreal Neurological Institute.
- Table 3:
White matter brain regions within the boundaries of the DTI tract atlas regions where control subjects were significantly greater than dyslexic subjects in the skeletonized fractional anisotropy
White Matter Tract Name t Statistic No. of Voxels MNI Coordinates x y z Body of corpus callosum 2.63035 13 −14 −1 36 Anterior limb of internal capsule left 2.88289 48 −17 11 2 Superior corona radiata left 3.11258 11 −16 −4 40 Posterior corona radiata left 2.74872 21 −18 −47 33 Sagittal stratum 2.62251 32 −46 −28 −12 Superior longitudinal fasciculus left 2.70963 55 −37 −23 32 Superior fronto-occipital fasciculus 3.04868 26 −21 9 20 Note:—DTI indicates diffusion tensor imaging; MNI coordinates, standard brain imaging coordinate system developed by the Montreal Neurologial Institute.
- Table 4:
White matter regions within the boundaries of the AAL* atlas where dyslexic subjects were significantly greater than control subjects in the skeletonized fractional anisotropy
Brain Region t Statistic No. of Voxels MNI Coordinates† Brodmann Areas x y z Precentral L 2.61863 23 −44 8 33 44 Frontal Inf Orb L 2.81102 21 −39 26 −14 47 Fusiform R 2.90205 19 37 −41 −24 37 Postcentral L 2.89957 15 −47 −23 45 3 Temporal Mid L 2.80589 36 −54 2 −32 20 Temporal Mid R 2.84047 16 61 −11 −16 21 Temporal Inf L 2.89029 39 −45 −21 −33 20 Cerebellum R 2.68122 116 41 −60 −39 Cerebellum L 2.76867 45 −42 −63 −48 Note:—L, indicates left; R, right; Inf, inferior; Orb, orbital.
* AAL refers to the automated anatomical labeling map which is a 3D map containing 116 brain regions co-registered to standard MNI space.
† MNI coordinates refers to a standard brain imaging coordinate system developed by the Montreal Neurological Institute.
- Table 5:
White matter brain regions within the boundaries of the DTI tract atlas regions where dyslexic subjects were significantly greater than control subjects in the skeletonized fractional anisotropy
White matter tract name t Statistic No. of Voxels MNI Coordinates x y z Middle cerebellar peduncle 2.796 31 −33 −52 −42 Note:—DTI indicates diffusion tensor imaging; MNI, MNI coordinates, standard brain imaging coordinate system developed by the Montreal Neurological Institute.
- Table 6:
DTI FA, eigenvalues for 21 subjects within a significant cluster near the left inferior frontal gyrus (for control subjects greater than dyslexic subjects)
Subject Identification FA Eigenvalues × 1e6 λL1 λL2 λL3 con 101 4096 1069 642 403 con 105 4180 1016 733 330 con 109 4059 1032 790 337 con 2658 4345 1190 665 440 con 3126 3878 1040 810 369 con 3131 5003 1158 699 359 con 3139 4262 1027 792 379 dys 103 3380 1161 768 549 dys 106 3659 986 744 387 dys 2253 3027 1004 723 503 dys 2254 3225 1102 845 502 dys 2291 3944 957 731 333 dys 2337 3220 1010 828 454 dys 2403 3877 1095 767 411 dys 2418 3033 1034 813 496 dys 2419 3668 1085 824 423 dys 2421 3813 1038 780 389 dys 2506 3746 987 721 387 dys 3021 4686 1122 652 405 dys 3053 3290 1031 790 457 dys 3198 4115 1046 752 410 Note:—DTI indicates diffusion tensor imaging; FA, fractional anisotropy; con, control; dys, dyslexic.
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