Article Figures & Data
Figures
- Fig 1.
Activation in contralateral M1 (arrows) displayed in axial sections for one subject in the first session. The right side of the sections corresponds to the left hemisphere, and the numbers in the color bar correspond to t values.
A and B, The fingers (A) and hand (B) are in almost identical locations (z plane, +58).
C and D, The wrist (C) and elbow (D) representations are located more medially, superior and posterior along the course of M1 (z plane, +59 and +61, respectively).
E and F, Note the considerable overlap of activated volumes within the arm and the clear separation of the foot (E) and tongue (F) (z plane, +66 and +28, respectively).
- Fig 2.
Activation of contralateral M1 in the second session in the same subject as in Figure 1. A comparison with the images in Figure 1 reveals a high degree of reproducibility in the somatotopy despite variations in the activated volumes.
A and B, Fingers (A) and hand (B).
C and D, Wrist (C) and elbow (D).
E and F, Foot (E) and tongue (F).
- Fig 3.
Two-dimensional scatter plots of the COGs in the 12 subjects (two sessions per subject) in the contralateral M1. Small dots represent individual COGs, and large dots indicate the mean COGs. Note the separate subdivisions for the foot, arm, and tongue and the clear somatotopic gradients within the arm representations in both the axial and coronal planes. The x, y, and z coordinates corresponding to those in Talairach space (21). Left, Axial plane with approximate contour of the precentral gyrus. Right, Coronal plane with the cortical surface and limited to the white matter.
- Fig 4.
Two-dimensional scatter plots of within-forearm COGs in contralateral M1 in the 12 subjects. COGs plane for the fingers, hand, wrist, and elbow are displayed in the axial plane.
A, First experimental session. The approximate contour of the precentral gyrus is outlined (as in Fig 3 left image, with the same colors as in Fig 3). The width x of each rectangle is 20 mm and the height y is 18 mm in Talairach space. Note the preserved somatotopic gradient in all 12 individual hand and forearm representations.
B, Second experimental session. Note the highly similar distribution and preserved somatotopic gradient of within-forearm COGs in almost all subjects compared with those of first session.
Tables
Paradigm Volume of Contralateral M1, mm3 Maximum t Value* COG Mean ± SD Range x y z Hand 5566 ± 2473 2976–9600 9.7 ± 2.0 −36 ± 3 −22 ± 4 58 ± 3 Fingers 2972 ± 1211 1264–5129 8.4 ± 2.6 −37 ± 2 −20 ± 5 58 ± 2 Wrist 4409 ± 2091 1520–8320 9.4 ± 2.4 −34 ± 3 −23 ± 4 59 ± 3 Elbow 2267 ± 1158 1200–7824 8.2 ± 2.3 −29 ± 4 −25 ± 4 61 ± 5 Foot 1457 ± 986 256–3888 5.9 ± 1.2 −6 ± 3 −33 ± 5 66 ± 5 Tongue† Left 3079 ± 2034 1088–7152 7.9 ± 1.5 −52 ± 3 −5 ± 3 29 ± 6 Right 3042 ± 164 512–6272 7.3 ± 1.7 56 ± 2 −6 ± 3 28 ± 5 Note.—Data are from the single-subject analysis. Numbers of subjects were as follows: 24 for the hand, fingers, wrist, and elbow experiments and 22 for the tongue and foot experiments.
* Data are the mean ± SD.
† For the tongue movements, the bilateral representations in the left and right hemispheres are shown.
Comparison P Value from t Test Mean Overlapping Volume, %* x y z Hand versus wrist <.001 <.07 <.001 49% ± 14 Hand versus elbow <.001 <.001 <.001 28% ± 16 Finger versus hand >.05 >.05 >.05 86% ± 10 Finger versus wrist <.001 <.001 <.001 34% ± 14 Finger versus elbow <.001 <.001 <.001 14% ± 10 Wrist versus elbow <.001 <.001 <.001 32% ± 14 Note.—Comparisons of the COGs and the percentage of overlapping volumes for the finger, hand, wrist, and elbow movements in contralateral M1. Data are from the single-subject analysis. Numbers of subjects were as follows: 24 for the hand, fingers, wrist, and elbow experiments and 22 for the tongue and foot experiments.
* Data are the mean ± SD.
Experiment and Session Mean Volume x y z Fingers First 2972 ± 1211 −37 ± 2 −20 ± 5 58 ± 2 Second 3023 ± 1263 −37 ± 3 −19 ± 4 57 ± 3 Wrist First 4409 ± 2091 −34 ± 3 −23 ± 4 59 ± 3 Second 3519 ± 1760 −34 ± 3 −22 ± 5 59 ± 3 Elbow First 2267 ± 1158 −29 ± 4 −25 ± 4 61 ± 5 Second 1984 ± 453 −29 ± 2 −26 ± 3 62 ± 3 Hand First 5566 ± 2473 −36 ± 3 −22 ± 4 58 ± 3 Second 5002 ± 1309 −37 ± 2 −20 ± 4 57 ± 3 Foot First 1457 ± 986 −6 ± 3 −33 ± 5 66 ± 5 Second 1436 ± 955 −6 ± 3 −33 ± 5 68 ± 4 Tongue, Left First 3079 ± 2034 −52 ± 3 −5 ± 3 29 ± 6 Second 3907 ± 2185 −51 ± 4 −6 ± 1 33 ± 6 Tongue, Right First 3042 ± 1640 56 ± 2 −6 ± 3 28 ± 5 Second 2589 ± 2121 56 ± 4 −7 ± 4 31 ± 6 Note.—COGs are the Talairach coordinates. Data are from the single-subject analysis. Numbers of subjects were as follows: 12 for the hand, fingers, wrist, and elbow experiments and 11 for the tongue and foot experiments.
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