| Project/Area Number |
06610078
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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 |
実験系心理学
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| Research Institution | Saga University |
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Principal Investigator |
IKEDA Yukinobu Saga University, Faculty of Culture and Education ; Professor, 文化教育学部, 教授 (50159638)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAI Makoto Saga Medical College, Department of Medicine ; Professor, 医学部, 教授 (80124808)
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| Project Period (FY) |
1994 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1996: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1995: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | black-white discrimination / resolution / plasticity / enucleation / compensation / visual cortex / brain lesion / uncrossed optic pathways / 視覚野破壊 / 視覚解像度 / 神経系の補償作用 / 出生時片眼摘出 / 大脳皮質視覚野破壊 / 同側視覚神経経路系 / フッデッドラットの視覚 / 縦縞-横縞弁別 / 上丘-視床後外側核系 / アルビノラットの視覚 / 神経系の発達 |
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| Research Abstract |
A black-white discrimination task was given to two types of one-eyed rats at 3 months of age. One type had the right eye removed within 24 hours after brith (OEB). The other had the right eye enucleated at 3 months of age (OET). Both OEBs and OETs could learn the discrimination task at the same performance level. When the right visual cortex of the rats was lesioned and the same task was given to the subjects, OEBs could relearn the task significantly faster than OETs. It was considered that this effect was lead by reorganization of the optic pathways, especially of the uncrossed visual pathways.
As it was seemed that an increased resolution capacity of uncrossed visual pathways in OEBs had an important role in the above mentioned effect, a horizontal-vertical discrimination task was employed to assess the levels of resolution capacity of OEBs and OETs. Both OEBs and OETs with their brain intact could acquire the discrimination between the stripes with a width of 30mm and relearn the task after the visual cortex contralateral to the remaining eye was lesioned. There was no difference in the relearning speed between the groups. Then, a width of stripes was gradually reduced ranging from 20mm to 5mm. It was found that the median width of the smallest stripes for OETs to discriminate was 10mm, and that of OEBs 7.5mm. Although OETs could not discriminate the smallest stripes which OEBs could, they were able to discriminate stripes one third smaller than those hypothesized. These findings suggested that our previously mentioned effect could not be explained only by resolution capacity. Cognition of the cue might be an important term upon the phenomenon. The approach to this problem is now undertaken in our laboratory.
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