Abstract
Linguistic information is processed at distinct levels from words to sentences and discourse. The left frontal regions play an important role in the process of constructing sentence structures by applying grammatical knowledge. We have used functional magnetic resonance imaging(fMRI), and shown that the left inferior frontal gyrus(L. IFG)and the left lateral premotor cortex(L. LPMC)are critically involved in syntactic processing. Moreover, we have demonstrated that a glioma in the L. IFG or L. LPMC is sufficient to cause selective deficits in syntactic processing. Furthermore, we have recently visualized three syntax─related networks by detailed analyses of abnormal activation patterns in the agrammatic patients, and have revealed that deficits in syntactic processing are associated with the functional reorganization of these networks. These results support the module hypothesis of human language.
