| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2004: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2003: ¥1,600,000 (Direct Cost: ¥1,600,000)
|
|---|
| Research Abstract |
In this research, we measured and analyzed the language function in the frontal regions using magnetic imaging techniques. This research was composed of four sections : (1)improvement in measurement and analysis techniques of MEG, (2)establishment of the time-frequency analysis method, (3)construction of language tasks that induce fMRI activation in the frontal regions, (4)measurement and analysis of the language function in the frontal regions using MEG. This report mainly presents the results of section (4)since sections (1)-(3) are fundamental researches for section (4).
In an MEG measurement, subjects were instructed to perform a word categorization task that evoked cortical activities in an fMRI study. The MEG responses were analyzed using dipole source analysis, frequency analysis, and time-frequency analysis. In the dipole source analysis, almost all the dipoles were localized in the temporal regions, while only a few dipoles were localized in, the frontal regions. However, in the frequency and tune-frequency analysis, magnetic responses were observed in the temporal and frontal regions. The alpha band amplitude was remarkable in the temporal regions while the delta band amplitude was distinctive in the frontal regions. This result showed that neurons in the temporal and frontal regions were activated by the language task. Desynchronization of the alpha band MEG in the temporal regions was observed for one of the subjects. This does not indicate the correlation of neural activities with a magnitude of the alpha band.
The results suggested that neural activities evoked by language tasks were found in the frontal regions, and these activities were related to the delta band MEG. Therefore, neural activities during language tasks may hardly synchronize with task onsets in the frontal regions.
|
