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Copying hand movements with or without symbolic meaning: an fMRI study
NemoImage
11, Number
5, 2000, Part 2 of 2 Parts ID
E bl@
COGNITION
(OTHER)
Copying hand movements with or without symbolic meaning: an fMRI study Shigeki Tanaka*?,
Toshio Inui*,
Sunao Iwakit,
Junji KonishiS, Toshiharu Nakait
*Graduate School of Informatics, Kyoto University, Kyoto, Japan. TLife Electronics Research Center, Electrotec Lab. & MRSL Electrotec Lab, MITI, Tsukuba, Japan. SGraduate School of Medicine, Kyoto University, Kyoto, Japan. Introduction Copying the movements of others contains various complicated cognitive processes such as visual perception of others’ movements, transformation of perceived movement to one’s own body and motor image, and simulation of one’s own motor image. We used fMR1 to study the neural substrates involved in copying hand movements in order to study the differences in cerebral activity during between copying well learned symbolic movements and that of novel movements. Three conditions were used. Pictures of a right hand at a posture with symbolic meaning (e.g., OK, victory, etc. .) were used in the first condition (referred as E+; with emblem). In the second condition (referred as E-; without emblem), a hand picture without any symbolic meaning were used. The third condition was the rest condition, fixation point were shown and subjects watched it. Method A total of 9 graduate students participated as normal volunteers. A task with three conditions was performed. Pictures of right hand were shown and the subjects were instructed to imitate them with their right hand. Both in E+ condition and E- condition, 10 pictures of a right hand were used. Each picture was shown for 2 s. IS1 was 1 s. 1 block was 30 s. Three conditions, rest, E+ and E-, were repeated for four times each in a counter balanced order in a total of 360 s. A conventional 1.5T MRI scanner was used (GE, Sigina). A total of 72 scans were acquired using a 1.5 T GE MR scanner with EPI sequence (TR/TE=5000/40ms, FA=90deg, FOV=220mm, matrix=64x64). The data of the first four scans were not used. Data analysis was performed using SPM 96. All EPI images were spatially normalized with MN1 template for group analysis. Results The thresholds for activation were set at p < 0.001 for voxel level. In comparison p < 0.05, but in 3) and 4) they were uncorrected. Activated In the comparison E- vs. E+, the Z score and Talairach coordinates of and 3.30 and (42 -48 56) for R-BA40. The activation in R-BA40 in Edetected when E- and/or E+ were compared with rest condition, which activity. L- ; left, R-; right, BA; Brodmann Area. 1. E+ vs. rest: L- BA7, L- BA2, L- BA4, L- BA6, R- cerebellum 2. E- vs. rest: R-cerebellum, L-BA4, L-BA7, L-BA40, L-BA2 3. E- vs. E+: L-BA40, R-BA40 4. E+ vs. E-: precuneus (BA7)
1) and 2) detected activations were corrected for multiple areas were listed in the order from high to low Z score. activation peaks were 3.50 and (-36 -30 56) for L-BA40 vs E+ and the activation in precuneus in E+ vs. E- did implies those activation should be attributed to negative
Discussion In E-t condition, subjects did not have to care much about their fingers, because they were well accustomed to take the same movements shown in Ef condition. Contrarily, subjects had to effortfully copy the movements in E- condition. Left BA 40 (supramarginal gyrus) activation was specific in E- condition, which is supposed to show deep involvement of this area in executing actions of novel combination of simple actions. Neuropsychologically, damage to BA 40 has been known to cause a conduction aphasia; patients with this symptom showed deficit in reproducing spoken words in correct order. One aspect of this aphasia is that the lower units of action (e.g., pronouncing syllables in a word or pronouncing words in a sentence) can not be composed in a proper order. A similar phenomenon is observed in an ideomotor apraxia: patients can perform each action correctly, but they cannot execute them in correct order as an integrated action. The left supramarginal gyrus is also a responsible lesion of ideomotor apraxia. In the point of action integration. conduction aphasia or ideomotor apraxia contain a similar cognitive processes with E- condition in our task. We suppose our result might successfully show the function of BA40 to compose higher movement from lower ones. References [I1 Krams M. et al.. Exp Brain Res 1998, 120: 386-98 [2] de Bleser R. et al., Brain Lang 1993, 45: 475-94.
s90
11, Number
5, 2000, Part 2 of 2 Parts ID
E bl@
COGNITION
(OTHER)
Copying hand movements with or without symbolic meaning: an fMRI study Shigeki Tanaka*?,
Toshio Inui*,
Sunao Iwakit,
Junji KonishiS, Toshiharu Nakait
*Graduate School of Informatics, Kyoto University, Kyoto, Japan. TLife Electronics Research Center, Electrotec Lab. & MRSL Electrotec Lab, MITI, Tsukuba, Japan. SGraduate School of Medicine, Kyoto University, Kyoto, Japan. Introduction Copying the movements of others contains various complicated cognitive processes such as visual perception of others’ movements, transformation of perceived movement to one’s own body and motor image, and simulation of one’s own motor image. We used fMR1 to study the neural substrates involved in copying hand movements in order to study the differences in cerebral activity during between copying well learned symbolic movements and that of novel movements. Three conditions were used. Pictures of a right hand at a posture with symbolic meaning (e.g., OK, victory, etc. .) were used in the first condition (referred as E+; with emblem). In the second condition (referred as E-; without emblem), a hand picture without any symbolic meaning were used. The third condition was the rest condition, fixation point were shown and subjects watched it. Method A total of 9 graduate students participated as normal volunteers. A task with three conditions was performed. Pictures of right hand were shown and the subjects were instructed to imitate them with their right hand. Both in E+ condition and E- condition, 10 pictures of a right hand were used. Each picture was shown for 2 s. IS1 was 1 s. 1 block was 30 s. Three conditions, rest, E+ and E-, were repeated for four times each in a counter balanced order in a total of 360 s. A conventional 1.5T MRI scanner was used (GE, Sigina). A total of 72 scans were acquired using a 1.5 T GE MR scanner with EPI sequence (TR/TE=5000/40ms, FA=90deg, FOV=220mm, matrix=64x64). The data of the first four scans were not used. Data analysis was performed using SPM 96. All EPI images were spatially normalized with MN1 template for group analysis. Results The thresholds for activation were set at p < 0.001 for voxel level. In comparison p < 0.05, but in 3) and 4) they were uncorrected. Activated In the comparison E- vs. E+, the Z score and Talairach coordinates of and 3.30 and (42 -48 56) for R-BA40. The activation in R-BA40 in Edetected when E- and/or E+ were compared with rest condition, which activity. L- ; left, R-; right, BA; Brodmann Area. 1. E+ vs. rest: L- BA7, L- BA2, L- BA4, L- BA6, R- cerebellum 2. E- vs. rest: R-cerebellum, L-BA4, L-BA7, L-BA40, L-BA2 3. E- vs. E+: L-BA40, R-BA40 4. E+ vs. E-: precuneus (BA7)
1) and 2) detected activations were corrected for multiple areas were listed in the order from high to low Z score. activation peaks were 3.50 and (-36 -30 56) for L-BA40 vs E+ and the activation in precuneus in E+ vs. E- did implies those activation should be attributed to negative
Discussion In E-t condition, subjects did not have to care much about their fingers, because they were well accustomed to take the same movements shown in Ef condition. Contrarily, subjects had to effortfully copy the movements in E- condition. Left BA 40 (supramarginal gyrus) activation was specific in E- condition, which is supposed to show deep involvement of this area in executing actions of novel combination of simple actions. Neuropsychologically, damage to BA 40 has been known to cause a conduction aphasia; patients with this symptom showed deficit in reproducing spoken words in correct order. One aspect of this aphasia is that the lower units of action (e.g., pronouncing syllables in a word or pronouncing words in a sentence) can not be composed in a proper order. A similar phenomenon is observed in an ideomotor apraxia: patients can perform each action correctly, but they cannot execute them in correct order as an integrated action. The left supramarginal gyrus is also a responsible lesion of ideomotor apraxia. In the point of action integration. conduction aphasia or ideomotor apraxia contain a similar cognitive processes with E- condition in our task. We suppose our result might successfully show the function of BA40 to compose higher movement from lower ones. References [I1 Krams M. et al.. Exp Brain Res 1998, 120: 386-98 [2] de Bleser R. et al., Brain Lang 1993, 45: 475-94.
s90