| Project/Area Number |
16500263
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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 |
Neurophysiology and muscle physiology
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| Research Institution | Osaka University |
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Principal Investigator |
SATO Hiromichi Osaka University, Graduate School of Medicine, Professor, 医学系研究科, 教授 (50154092)
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| Co-Investigator(Kenkyū-buntansha) |
SHIMEGI Satoshi Osaka University, Graduate School of Medicine, Associate Professor, 医学系研究科, 助教授 (20271033)
赤崎 孝文 大阪大学, 健康体育部, 助手 (30335393)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2004: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | visual information processing / parallel pathway / metacontrast / primary visual cortex / receptive field / stimulus characteristics / contextual modulation |
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| Research Abstract |
In the primary visual cortex (V1), a response to a stimulus in the classical receptive field (CRF) is suppressively modulated by a stimulus presented in the CRF surround (SRF). We examined the temporal dynamics of the response to CRF stimulation and the surround suppression in terms of spatial-frequency (SF) tuning of cat V1 neurons using stationary flashes of a circular sinusoidal grating patch (duration, 500ms) and an annulus (50ms) as CRF and SRF stimuli. In Experiment 1 (N=39), we stimulated CRF with grating patch of optimal orientation and varying SFs. The preferred SF shifted from low to high along time course of response. In Experiment 2 (N=48), CRF was stimulated with grating of optimal orientation and SF, while SRF was stimulated with grating of optimal orientation and varying SF sandstimulus-onset-asynchrony (SOA). SF tuning of surround suppression changed along time course of response, and effective SF of surround suppression shifted from the SF lower than that of CRF stimulus (CRF-SF) to that near CRF-SF. By changing SOA, we examined surround suppression on different temporal phases of CRF response. SRF stimulus only with low SF (<0.2c/deg) suppressed the initial phase of CRF response. These results suggest that multiple mechanisms with different SF- and temporal characteristics are involved in the surround suppression.
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