2003 Fiscal Year Final Research Report Summary
INFORMATION REPRESENTATION IN THE MID-LEVEL VISUAL CORTEX
| Project/Area Number |
13308048
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
神経・脳内生理学
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| Research Institution | OSAKA UNIVERSITY |
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Principal Investigator |
OZAWA Izumi OSAKA UNIVERSITY, GRADUATE SCHOOL OF FRONTIER BIOSCIENCES, PROFESSOR, 生命機能研究科, 教授 (20324824)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Hiroki OSAKA UNIVERSITY, GRADUATE SCHOOL OF FRONTIER BIOSCIENCES, ASSIATANT PROFESSOR, 生命機能研究科, 助手 (40335386)
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| Project Period (FY) |
2001 – 2003
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| Keywords | texture / binocular disparity / spatial frequency / orientation selectivity / visual cortex / visual neuroscience |
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| Research Abstract |
1. Responses of neurons in areas 17 and 18 of the cat were studied using textured stimuli, also known as second-order or envelope stimuli in addition to standard luminance-defined stimuli.
(1) Neurons that respond to textured stimuli exhibit selectivities for binocular disparity defined by these stimuli if they are selective for disparity defined by luminance variations. The optimal disparities for the two types of stimuli are found to be closely matched, indicating "cue invariance" for binocular disparity.
(2) Signals from the two eyes representing texture-defined borders and luminance-defined borders converge to a single neuron at a single common site. This has been shown by tests in which different types of stimuli (texture and luminance-based) are presented dichoptically to the two eyes.
2. Application of a reverse correlation technique in the frequency domain (a joint domain of orientation and spatial frequency) has been shown to accelerate measurement of tuning characteristics of neurons by a large factor. The new time-efficient technique allows rapid acquisition of comparable or better data than that possible by traditional methods using drifting sinusoidal grating stimuli. Therefore, the new technique is able to replace the conventional methods in the majority of cases.
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Research Products
(16 results)
