Summary of Research Project Results Under the JSPS FY2000
"Research for the future Program"
| 1.Research Institution | | Okazaki National Research Institutes |
| |
| 2.Research Area | | Life Science |
| |
| 3.Research Field | | Higher Brain Functions |
| |
| 4.Term of Project | | FY1996〜FY2000 |
| |
| 5.Project Number | | 96L00202 |
| |
| 6.Title of Project | | Neural mechanisms of visual cognition in the cerebral Cortex |
7.Projetct Leader
| Name |
Institution,Department |
Title of Position |
| Komatsu Hidehiko |
Okazaki Natl. Res. Inst, Inst. for Physiol. Sci |
Professor |
8.Core Members
| Names |
Institution,Department |
Title of Position |
| Ito Minami |
Okazaki Natl. Res. Inst, Inst. for Physiol. Sci |
Associate Professor |
| Hanazawa Akitoshi |
Okazaki Natl. Res. Inst, Inst. for Physiol. Sci |
Research Associate |
| Ogawa Tadashi |
Okazaki Natl. Res. Inst, Inst. for Physiol. Sci |
Research Associate |
9.Cooperating Researchers
| Names |
Institution,Department |
Title of Position |
| Murakami Ikuya |
Okazaki Natl. Res. Inst, Inst. for Physiol. Sci |
Research Fellow |
| Kinoshita Masaharu |
Okazaki Natl. Res. Inst, Inst. for Physiol. Sci |
Research Associate |
| Koida Kowa |
Okazaki Natl. Res. Inst, Inst. for Physiol. Sci |
Research Associate |
10.Summary of Research Results
1. We have shown that non-linear processing of cone signals takes place in the primary visual cortex (V1) of the macaque monkey that generate neurons sharply tuned for hue and saturation of color. This indicates that V1 plays vital role in the formation of color representation observed in the higher visual areas. 2. Macaques lacking one type of cone pigment were detected for the first time. ERG recording have confirmed that sensitivity to red lights is extremely low in these monkeys compared with normals. 3. Neurons were found in are V4 that were specifically sensitive to particular 3-dimensional (3D) surface textures. These neurons responded to texture patterns consisting of many fine shading patterns and were sensitive to the density, size and direction of shading. A bias in the preferred shading direction was consistent with a bias observed in human perception in shape from shading. These results strongly suggest that V4 is involved in perception of 3D surface textures. 4. We found that neurons in area MSTd systematically represent 3D orientation of a surface defined by moving random dots. These neurons integrate information of various directions and velocities across surface stimuli and seem to be involved in the process of recovering surface orientation from moving stimuli. 5. We found that neurons in the retinotopic representation of the blind spot in V1 are activated when perceptual filling-in occurs at the blind spot even though there is no retinal input to this area. It was suggested that spatial aspects of stimuli presented on the blind spot are represented as the difference in the activities across neurons with different spatial properties. 6. We found that neurons exist in V1 that encode the luminance of homogeneous surfaces that cover the receptive field. Some of these neurons were modulated by the luminance of the surround and exhibited activity which parallels with the brightness perception of the surface. This indicates that spatial integration of luminance information occurs in V1.
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11.Key Words
(1)Vison、(2)Cerebral Cortex、(3)Monkey
(4)Perception、(5)Color、(6)Texture
(7)Motion、(8)Filling-in、(9)Cognition
12.References
[Reference Articles]
| Author |
Title of Article |
| Komatsu, H. |
Mechanisms of central color vision. |
| Journal |
Volume |
Year |
Pages Concerned |
| Current Opinion in Neurobilogy |
8 |
1998 |
503-508 |
| Author |
Title of Article |
| Onishi. A. et al |
Dichromatism in macaque monkeys. |
| Journal |
Volume |
Year |
Pages Concerned |
| Nature |
402 |
1999 |
139-140 |
| Author |
Title of Article |
| Kondo, H. and Komatsu, H. |
Suppression on neuronal responses by a metacontrast masking stimulus in monkey V4. |
| Journal |
Volume |
Year |
Pages Concerned |
| Neuroscience Research |
36 |
2000 |
27-33 |
| Author |
Title of Article |
| Hanazawa, A. et al |
Neural selectivity for hue and saturation of colour in the primary visual cortex of the monkey. |
| Journal |
Volume |
Year |
Pages Concerned |
| European J. Neuroscience |
12 |
2000 |
1753-1763 |
| Author |
Title of Article |
| Komatsu, H. et al |
Neural responses in the retinotopic representation of the blind spot in the macaque V1 to stimuli for perceptual fining - in. |
| Journal |
Volume |
Year |
Pages Concerned |
| J. Neuroscience |
20 |
2000 |
9310-9319 |
| Author |
Title of Article |
| Hanazawa, A. and Komatsu, H. |
Influence of the direction elemental luminance gradients on the responses of V4 cells to textured surfaces. |
| Journal |
Volume |
Year |
Pages Concerned |
| J. Neuroscience |
|
2001 |
in press |
[Reference Books]
| Author |
Title of Book |
| Komatsu, H. |
Neural representation of color in the inferior temporal cortex of the macaque monkey. in: The Association Cortex-Sfrucfure and Functions |
| Publisher |
Year |
Pages |
| Harwood academic publishers |
1997 |
pp269-280 |
| Author |
Title of Book |
| Komatsu, H. |
The physiological substrates of color constancy. In: Perceptual Constancy |
| Publisher |
Year |
Pages |
| Cambridge University Press |
1998 |
pp352-372 |
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