2001 Fiscal Year Final Research Report Summary
Neural mechanisms underlying the perception of transparent wide-field visual flow
| Project/Area Number |
12680397
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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 Dep.of inf, &comm.Eng, Tamagawa University, Associate Professor, 工学部, 助教授 (60142006)
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| Co-Investigator(Kenkyū-buntansha) |
SAITO Hide-aki Dep. of inf, &comm.Eng, Tamagawa University, Professor, 工学部, 教授 (30215553)
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| Project Period (FY) |
2000 – 2001
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| Keywords | wide-field visual flow / bi-directional transparent motion / perception of moving / motion aftereffect / Spontaneous discharge / directionally-selective cell / monkey / MST area |
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| Research Abstract |
We investigated perceptional properties of motion aftereffect and its underlying neural mechanisms caused by bi-directional wide-field transparent motion. Prolonged presentation of bi-directional transparent motion induced unidirectional illusionary motion percept. After adapted by unidirectional wide-field visual flow, spontaneous discharge levels of directionally-selective(DS) cells in MST of macaque monkey were decreased by about 25% in comparison with those measured before presentation of adaptation stimulus. This result strongly suggests that perceived direction of illusionary motion induced by motion aftereffect is directly related to the distribution of spontaneous discharge levels among MSTDS cells. To reveal neural substrate for different directional percept in transparent motion stimulation and in motion aftereffect thereby, we analysed tuning properties of DS cells to bi-directional wide-field transparent flow in which constituent coherent flows moved with angular separation of 90 or 120 degrees. DS cells could be classified into two-subtypes, namely component type and integration type according to the tuning to bi-directional flow. Component cells tuned to component motion in transparent flow whereas integration cells tuned to integrated motion in bi-directional flow. Neural representation by component cells is thought to bring bi-directional percept for transparent flow and that by integration cells is thought to bring unidirectional percept in motion aftereffect.
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