著者

竹内 龍人

出版者

一般社団法人映像情報メディア学会

雑誌

映像情報メディア学会技術報告 (ISSN:13426893)

巻号頁・発行日

vol.33, no.24, pp.7-14, 2009-06-16

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シーン(情景)がもつ意味的カテゴリーや空間レイアウト,シーンに含まれるいくつかの主要なオブジェクトを総称してシーンのgistという.本稿では,シーンのgistがいかにして検出,認識されているか,その視覚メカニズムの解明に向けた研究を概説する.たとえ見たことのない画像でも,そのgistは一目で認識される.gistの情報は,高次の意味的ネットワークを駆動することにより,オブジェクトの検出や認識を促進する.視覚システムはまた,シーンの情報を積極的に利用して視覚探索を行う.gistの認識過程や,シーン情報に基づくトップダウンの過程を組み込んだ視覚探索のモデルは,自然画像を探索する際の観察者の注視領域を精度よく予測することができる.

著者

和崎 夏子 竹内 龍人

出版者

日本視覚学会

雑誌

VISION (ISSN:09171142)

巻号頁・発行日

vol.35, no.4, pp.146-155, 2023-10-20 (Released:2023-10-25)

参考文献数

24

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Perceptual grouping has been examined mainly by presenting visual stimuli in a 2-D field. In this study, we examined the characteristics of perceptual grouping in 3-D space by utilizing virtual reality (VR) technology. We used an elongated thin cylinder as the basic element. Participants were asked to find a predefined target made of five cylinders among the 1000 cylinders in the VR space. The orientation of the five cylinders of the target was varied systematically. The participant could move their head or body freely while searching. We found that in the VR space, the observers were sensitive to the structure in which the elements were oriented in parallel with each other. This structure was difficult to find in the 2-D field. These results indicate that in a 3-D space, the elements are perceptually grouped by utilizing the information from head and body movements which was not available while searching for a target in the 2-D field.

著者

吉本 早苗 竹内 龍人

出版者

日本基礎心理学会

雑誌

基礎心理学研究 (ISSN:02877651)

巻号頁・発行日

vol.33, no.1, pp.19-27, 2014-09-30 (Released:2014-11-26)

参考文献数

38

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It is known that the perceived direction of a directionally ambiguous test stimulus is influenced by the moving direction of a preceding priming stimulus. To examine the spatial property of motion priming, we manipulated the spatial distance between the priming and test stimuli. Subjects judged the perceived direction of 180-deg phaseshifted sine-wave gratings (test stimulus) displayed immediately after the offset of a priming stimulus. We found that a brief priming stimulus induced negative motion priming when it was spatially distant from the test stimulus. We also found that positive motion priming was observed when both priming stimulus and test stimulus were presented at the peripheral retina. Negative motion priming was observed regardless of the position of the stimuli when the duration of the priming stimulus was longer. We conclude that the effect of spatial distance on the visual motion priming could be explained by the activation of a center-surround antagonistic motion detecting mechanism when a brief priming stimulus was used.

著者

吉本 早苗 竹内 龍人

出版者

The Japanese Psychological Association

雑誌

心理学研究 (ISSN:00215236)

巻号頁・発行日

vol.83, no.4, pp.357-362, 2012

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It is known that a directionally ambiguous test stimulus is perceived to move in the same direction as a brief preceding priming stimulus when both stimuli are presented at the same retinal location (visual motion priming). To examine the spatial properties of visual motion priming under different retinal illuminance, we manipulated the distance between the priming and test stimuli. Participants judged the perceived direction of 180 deg phase-shifted, thus directionally ambiguous, sine-wave gratings (test stimulus) displayed immediately after the offset of a smoothly drifting priming stimulus. The distance between priming and test stimuli was varied from 0 to 10 deg in visual angle. Since the spatial summation area broadens under low retinal illuminance, we predicted that visual motion priming would be more conspicuous under mesopic vision than under photopic vision. Contrary to this prediction, as the retinal illuminance decreased and the distance between the primer and the test stimulus increased, the test stimulus was perceived to move in the direction opposite to the priming stimulus. We speculate that different motion integration systems are functioning depending on the retinal illuminance.