演題詳細
Symposium
脳広域ネットワークの機能構築イメージングにむけた挑戦
Challenges of imaging functional architecture of large-scale network
開催日 | 2014/9/11 |
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時間 | 17:00 - 19:00 |
会場 | Room F(302) |
Chairperson(s) | 定藤 規弘 / Norihiro Sadato (自然科学研究機構 生理学研究所 大脳皮質機能研究系 / Department of Cerebral Research, National Institute for Physiological Sciences, Japan) 林 拓也 / Takuya Hayashi (理化学研究所 ライフサイエンス技術基盤研究センター / Functional Architecture Imaging Unit, RIKEN Center for Life Science Technologies, Japan) |
高解像度fMRIを用いたヒト視覚野の研究
Exploring Human Visual Cortex With High-Resolution fMRI
- S1-F-3-5
- 程 康 / Kang Cheng:1
- 1:理化学研究所脳科学総合研究センター / Lab. for Cognitive Brain Mapping, RIKEN, BSI, Japan
In this talk, I will present the results from three high-resolution (sub-millimeter) fMRI studies, all conducted on a 4 Tesla MRI system. In the first study, using both direct mapping and indirect decoding approaches, we demonstrated that orientation selectivity in human V1 can be relaibly revealed. In particular, we found that large drining veins contribute significantly to orientation-selective BOLD signals. These results are strikingly surprising and invite more detailed anatomical and functional studies of draining veins at various spatial scales. In the second study, we manupulated the spatial resolution of fMRI data and analyzed the geometric relationship between 1) the spatial resolution of imaging voxels, 2) the systematic increase and decrease in the proportion of direction-selective voxels, and 3) the repeatition periodicity of assumed underlying direction-selective hypercolumns in hMT+. Using this approach, we were able to indirectly estimate the average size of hypercolumns for motion direction in hMT+, which was approximately 0.7 mm in the narrow dimension. Finally, in the third study elucidating the object-selective responses in human occipito-temrpoal cortex, I will highlight the unique advantage of doing these experiments at higher resolutions.