| Project/Area Number |
09670659
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Neurology
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
TABIMATSU Shozo Dept. of Clinical Neurophysiology, Graduate School of Medical Sciences, Kyushu University, Professor, 大学院・医学系研究科, 教授 (40164008)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1999: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Visual information / Parallel processing / Magnocellular system / Parvocellular system / Magnetoencephalography / Intracerebral network |
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| Research Abstract |
1. Background : There are two major parallel pathways that process visual information processing in human. Magnocellular (M) system projects to the parietal lobe via the primary visual cortex (V1) and is important for motion and stereopsis. Parvocellular (P) system consist of the ventral pathway from V1 to the temporal lobe and plays an important role in color and from perception. We investigated the visual information processing by using visual evoked potentials (VEPs), visual evoked magnetic fields (VEFs) recorded by magnetoencephalography (MEG) and event-related potentials (ERPs).
2. Subjects and Methods : Visual stimuli such as color and motion were used to segregate the function of the M and P pathways in V1 in normal subjects. Then, visual stimuli such as words and faces were used to study the function of the ventral pathway. In addition, we studied the visual function in patients with higher brain dysfunction.
3. Results : We obtained the following results. 1) Chromatic stimuli evoked N120 in VEPs and N120m in VEFs while motion stimuli evoked P120 in VEPs and P120m in VEFs. Their neural generators were estimated in V1 but they showed different behaviors. These results suggest that the presence of the parallel processing in V1. However, we could not obtain reliable signals in MEG from the higher visual cortex. 2) VEPs to words and faces showed P170 at the vertex. However, we could not obtain reliable sources of these potentials by MEG. 3) Our methods were useful in evaluating the brain function in patients with associative visual agnosia and cerebral achromatopsia.
4. Perspective : A combined use of VEPs, MEG and ERPs is useful in evaluating the spatiotemporal information processing in normal subjects as well as patients. Our future plan is aimed at combining the electrophysiological data with neuroimaging techniques such as position CT and functional MRI to assess the human brain function.
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