| Objective: Observe the linguistic-functional cortex so as to identify the effect of age and sex on normal language processing by ER-fMRI and to observe whether a left or right predominance for linguistic-functional cortex exits or not.Materials and Methods: We examined 112 healthy volunteers of 20-65 years old, of whom 54 are male and 58 are female. The average age is 43.9. All of the subjects, whose native language is Chinese, have got through the primary school education at least. All of the subjects were right-hand dominant and none of them had serious impairments of the heart, liver, kidney, etc. or history of cerebral tumors and other cranial or cerebral diseases or psychopharmaca-taking history. We divided all the subjects into 4 groups according to their gender and age as follows: Group A, male, younger than 50 (including 50);Group B, female, younger than 50 (including 50);Group C, male, older than 50;Group D, female, older than 50. Each group finished 4 tasks, to read "i" loudly or silently, to read Chinese words loudly or silently, and each subject finished two of them. The occurrence of stimulus turned up in a way of visual presentation.Results: There were no statistical differences about the activated voxel andintensity change in the linguistically functional cortex between healthy male and female individuals of different decades (ANOVA, P>0.05). The activated areas include bilateral frontal lobe, temporal lobe, parietal lobe, occipital lobe and bilateral cerebellar hemisphere. According to the matched-pairs design text, there were no statistical differences of the activated voxel and intensity change in bilateral activated areas (/-test, P>0.05). Although the activated areas were not quite the same when each of the above four tasks were being performed and more activation elicited by overt-reading than that of covert-reading were observed, there was no statistical difference of the activated voxel and intensity change in the same activated areas of each task (ANOVA, P>0.05). The activation of supramarginal gyms and angular gyrus was only found when tasks of reading words silently and loudly were performed respectively.Conclusion: There were no age and gender differences in linguistic- function regions of healthy individual whose native language is Chinese. It is bilateral-equilibrium and no linguistic hemisphere's predominance exits. This characteristic is different from the left-hemisphere dominance of western languages. Although there were no statistical differences of the activated voxel and intensity change between overt-reading and covert-reading, the activated areas of overt-reading are so unreliable that the way of overt-reading to study the linguistic-function regions of human brain is improper to some extent. No activation of supramarginal gyrus and angular gyrus while the subjects were reading "i" silently or loudly suggesting that such areas have an effect on the semantic and lexicon aspects of normal language processing.Part 2: An fMRI research of the linguistic-functional cortex in patients with laryngocarcinoma during postoperativepronunciation rebuildingObjective: Observe the changes of linguistic-function cortical areas in patients who had undergone total resection of laryngocarcinoma during their pronunciation rebuilding process with ER-fMRI and identify the differences of linguistic-function cortex between such patients and healthy individuals.Material and Methods: 18 patients who had undergone total resection of laryngocarcinoma are examined. The patients were aged from 47~71 with the average age was 58.4, of whom 14 were male and 4 were female. All of the subjects, whose native language is Chinese, have got through the primary-school education at least. All of the subjects were right-hand dominant and none of them had serious impairments of the heart, liver, kidney, etc. or history of cerebral tumors and other cranial or cerebral diseases or psychopharmaca-taking history .We divided all the subjects into three different groups according to the pronouncing- evaluation list. The groups are as follows: Group 1, bad pronunciation group, in which the patients' score <5;Group 2, moderate pronunciation group, in which the patients' score ^5 but =^10;Group 3, good pronunciation group, in which the patients' score >10. The task for each group was to read "i" and Chinese words loudly. The occurrence of stimulus turned up in a way of visual presentation.Results: The activated areas in patients approximated to that of healthy individuals. There were statistical differences of the activated voxel and intensity change among all the groups in the left middle frontal gyms, left SMA, and left anterior cingulate gyrus while the task of overt-reading "i" was being performed(ANOVA, PO.05). There was significant increase in the activated voxel and intensity change of the above areas in group 2 than those of the other groups, and there were no differences among the other groups;while the task of overt-reading words was being performed, there were statistical differences of the activated voxel and intensity change among all the groups in the left middle frontal gyrus, left precentral gyrus, left postcentral gyrus, left SMA, and right fusiform gyrus (ANOVA, P<0.05). There was significant increase in the activated voxel and intensity change of the above areas in group 2 than those of the other groups. There were no differences among the other groups. No statistical differences of the symmetrical activated areas elicited by each task existed according to the result of the matched-pairs design text (r-test, P>0.05). As to some other ROI, some findings were also obtained: (1) insular lobe, there was significant difference among all groups about the activation-rate (chi-square test, ^=33.830, P=0.000). The activation-rate of group 1,2, and 3 were bigger than that of the normal group, and there were no differences of the activation-rate in the former three groups;(2) lenticular nucleus and parahippocampal gyrus, there were significant differences among all groups about the activation-rate (chi-square test, ^=35.166, P=0.000;^=34.985, P=0.000). The activation-rate of group 2 and 3 were bigger than that of group 1 and the normal group, and there was no difference between group 2 and group 3, as well as between group 1 and the normal group.Conclusion: The linguistic-function cortex position of the patients in groupl, 2, and 3, which also were bilateral-equilibrium, were the same with healthy individuals and no formation of new linguistic cortex was observed. Comparing with the patients who were classified to the bad pronunciation group, there was significant increase in the activated voxel and intensity change of the patients whowere classified to the moderate pronunciation group in the left middle frontal gyrus, left precentral gyrus, left postcentral gyrus, left SMA, left anterior cingulate gyrus and right fusiform gyrus. Therefore, we speculate that these regions played an important part in the progress of pronunciation rebuilding process, and instructed the patients to learn better pronunciation. However, just as healthy individuals, during the later period of pronunciation rebuilding process, the activated voxel and intensity change in these regions decreased, which we think that the learning and instruction effect weakened as well as the cortex activations was not significant any more once the patient had mastered pronunciation techniques during the later period. At the same time, insular lobe, lenticular nucleus and parahippocampal gyrus also played some part in the progress of pronunciation rebuilding process and their functions need to be further researched and discussed. |
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