2005 Fiscal Year Final Research Report Summary
Neural mechanism for space perception based on visual flow
| Project/Area Number |
16500087
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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 |
Intelligent informatics
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| Research Institution | Tamagawa University |
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Principal Investigator |
HIDA Eiki Tamagawa University, College of Engineering, Professor, 工学部, 教授 (60142006)
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| Co-Investigator(Kenkyū-buntansha) |
SAITO Hideaki Tamagawa University, Research Institute, Researcher, 学術研究所, 特別研究員 (30215553)
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| Project Period (FY) |
2004 – 2005
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| Keywords | Visual flow / Neural representation / Wide-field motion perception / Motion adaptation / Motion integration / Coherent motion / MST area / MT area |
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| Research Abstract |
(1)We examined tuning properties of MST and MT cells for both bi-directional transparent motion and plaid pattern motion. MT cells responded best when either flow in bi-directional motion coincided with preferred direction of the cell. Some MST cells exhibited direction tuning as shown in MT cells. Others showed maximal responses to the integrated motion of bi-directional flow. MT cells responded best for component motion or pattern motion of plaid pattern whereas MST cells showed maximal responses for pattern motion of plaid stimulus. We proposed functional connection model from MT pattern cells to MST cells.
(2)We investigated how perceptual properties for coherent visual flow depended on the adapting stimuli. When coherent motion was used as adaptation stimulus, performance on discrimination of visual flow was monotonically degraded as the coherency of the adapting stimulus was increased. Percentage of correct response after adapted by dynamic random pattern was higher than that after adapted by static pattern. These results suggested that two sorts of adaptation mechanisms (bottom-up mechanism and top-down mechanism) concurrently operate in our visual system.
(3)We examined perceptual changes in humans caused by visual flow adaptation. Moreover, we analyzed change of activities of both MST and MT cells after visual flow adaptation. Time course of spontaneous discharges after adaptation in MST cells resembled with both time course of the perception of motion aftereffect and that of recovery of sensitivity from adapted state.
(4)Direction tuning of both MT and MST cells for bi-directional transparent motion and plaid motion has revealed that component motion representation and integration motion representation are present in MST and component motion representation and pattern motion representation are present in MT.
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