Abstracts

Rationale: In the setting that the epileptogenic zones locate near the eloquent cortexes, we have to take into account an accurate functional areas and an ability of neural plasticity for epilepsy surgery. In this paper, we hypothesized that the mechanism of speech when the bilinguals spoke the second language could be simulated the functional acquisition of speech after damage of the primary language areas. We examined the activated cortexes in the bilinguals using functional MRI (fMRI) and assessed the cortical and subcortical network. Methods: We analyzed the positive BOLD effect areas in 32 Japanese/English bilinguals. We separated into the following two groups by age of first exposure of English (2nd language); the Early group (less than 7-year-old), and the late group (7-year-old and older). The functional activating areas were assessed by BOLD response during hearing language tasks in English and Japanese using 3T MRI. Data were analyzed by statistical method using MATLAB and SPM software. Results: The early group resulted that the activation areas were bilateral superior-middle temporal gyrus with left side dominancy. The late group showed an activation in bilateral superior-middle temporal gyrus and left frontal lobe. In addition, the late group presented a different BOLD effect in the corpus callosum. Conclusions: The language acquirement after critical period of completing the primary language is associated with frontal lobe and interhemispheric communication.  Funding: -