ISSN : 1226-9654
본 연구는 시각탐색과제를 사용하여 타원의 수직 및 수평방위와 음영이 생성한 형태 입체 정보가 어떠한 차별적 처리 효과를 가지는지 알아보았다. 실험 1에서는 타원의 장축과 단축의 비율을 1:4, 2:4, 3:4로 구성하여 수평 및 수직 방위성의 정도를 조작하였고, 각각의 표적/배경 역할을 바꾸어 탐색 수행의 차이를 알아보았다. 실험 2에서는 음영이 첨가된 타원으로 오목 또는 볼록을 구성하고, 방위를 조작하였다. 방위의 효과는 실험 1, 2를 통하여, 수평 자극을 배경으로 갖는 수직 표적자극은 반대의 자극 구성에 비해 탐색시간이 짧았으며, 표적유무에 따른 탐색 기울기 차이도 없었다. 실험 2에서 조작한 음영의 효과는 방위가 동일한 경우 볼록 자극을 배경으로 갖는 오목 표적 자극이, 반대의 자극 구성에 비해 탐색시간이 짧았다. 특히 배경이 볼록 자극으로 구성된 경우, 오목 표적의 탐색기울기가 방위 간 동일한 것으로 나타났으나, 배경이 오목 자극으로 구성된 경우 수평 방위와 수직 방위의 탐색 기울기가 차이 있는, 즉 방위와 음영 정보의 상호작용이 있었다. 수평 배경 자극은 음영이 볼록인 경우는 빠른 표적 탐색 수행을, 그리고 오목인 경우는 표적 탐색 수행이 크게 저하되었으며, 반면에 수직 배경 자극은 음영 정보에 따른 수행의 병화가 수직의 경우와는 반대의 경향을 보였다. 본 연구에서 수직과 수평이 시각체계에서 차별적으로 처리될 가능성을 시사하는 결과를 얻었으며, 특히 수평 볼록 자극은 목표 자극의 pop-out을 가장 강하게 하는 배경의 역할을 하는 것으로 보인다. 이는 정상적인 조명이 있는 자연 장면에서 수평 자극은 배경으로, 수직 자극은 전경으로 지각하는 편향이 있을 개연성을 시사하고 있다.
We investigated whether orientations shape-from-shading of oval pattern influence visual search processes differently. In Experiment 1, the strength of orientation was manipulated by using three ratios of vertical to horizontal axes and vice versa: 1:4, 2:4, 3:4. Each type of oval was used for target or distracter. In Experiment 2, shape-from-shading was applied to oval pattern, so the patterns were convex or concave. In Experiment 1, vertically elongated oval target conditions were faster than horizontally elongated target conditions. And search asymmetry was getting obvious as ratio between horizontal and vertical axis became low. In Experiment 2, there was an interaction between orientation and shading. A vertical target was popped-out quickly against horizontal oval background. only when background was convex. In contrary, search for horizontal target against vertical background was faster in case of concave background than in convex. The results strongly suggest that horizontal or vertical orientation are not equally sensitive in visual system. Visual system seems to find an vertical object at horizontal background easier than an opposite case under naturally lit environment.
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Brainard, D. H, (1997) The Psychophysics Toolbox, Spatial Vision 10,
Braun, (1994) Visual search among items of different salience removal of visual attention mimics a lesion in extrastriate area V4 Journal of Neuroscience,
Brown, L. E, (2002) Feature-specific perceptual processing dissociates action from recognition,
Campbell, F. W, (1996) The effect of orientation on thevisual resolution of gratings,
Campbell,F.W.,, (1968) Application of Fourier Analysis to the visibility of gratings,
Coppola, D. M, (1998) Unequal distribution ofcardinal and oblique contours in ferret visual cortex,
Cumming, B. G, (2002) An unexpected specialization for horizontal disparity in primate primary visual cortex.,
Yund, (1982) The orientation and direction selectivity of cells in macaque visual cortex,
Duncan,J.,, (1989) Visual search and a stimulus similarity,
Enns, (1990) Influence of scene-based properties on visual search,
Furmanski, C. S, (2000) An oblique effect in human primary visual cortex,
Hansen, B. C, (2004) A horizontal bias in human visual processing of orientation and its correspondence to the structural components of natural scenes,
Huang, L, (2002) Symmetry detection and visual attention: a "binary- map" hypothesis,
Hubel, (1968) Journal of physiology,
Hubel,D.H.,Wiesel,T.N.,Stryker,M.P, (1978) Anatomical demonstration of orientation columns in macaque monkey,
Kelly, D. M, (2001) Detection of Glass Patterns by Pigeons and Humans: Implication for Differences in Higher-Level Processing,
Kleffner, (199218-36) On the perception of shape from shading,
Li, Peterson, Freeman , (2003) The Oblique Effect: a neural basis in the visual cortex,
Murata. A, (1995) Vertical axis awareness in 3d environments,
Nakayama, (1986) Serial and parallel processing of visual feature conjunctions,
Nothdurft, H. C, (1999) Focal attention in visual search,
Oliver, C. N. L, (2003) Attentional guidance by salient feature singletons depends on intertrial contingencies,
Orban, (1984) Human orientation discrimination tested with long stimuli,
Ostrovsky, Y, (2005) Perceiving illumination inconsistencies in scenes.,
Pelli, D. G, (1997) The VideoToolbox software for visual psychophysics: Transforming numbers into movies,
Ramachandran,V.S, (1988) Perceiving shape from shading,
Regan, (1986) Periodicity in orientation discrimination and the unconfounding of visual information,
Rensink, R, (2004) The influence of cast shadows on visual search,
Ruxton, G. E, (2004) What, if anything, is the adaptive function of countershading? ,
Sireteanu, R, (1995) Perceptual learning in visual search: Fast, enduring, but non-specific.,
Snowden, R. J, (1998) Texture segregation and visual search: A comparison of the effects of random variations along irrelevant dimensions,
Sun, J. Y, (1996) Preattentive Percetion of Elementary Three-Dimensional Shapes,
Sun, J. Y, (1998) Where is the Sun?,
Tomonaga, M, (1998) Perception of shape from shading in chimpanzees(Pan troglodytes) and humans(Homo sapiens). ,
A, (1986) Features and objects in visual processing,
Treisman,A.,, (1980) A feature integration theory of attention,
Treisman,A, (1988) Feature analysis in early vision:Evidence from search asymmetries,
A, (1985) A diagnostic for preattentive processing of separable features Journal of Experimental Psychology,
Wolfe, J. M, (2003) Changing Your Mind: On the Contribution of Top-Down and Bottom-up Guidance in Visual Search for Feature Singletons,
The Korean Journal of Experimental Psychology,
Effect of Orientation and Shading,
of Oval Patterns on Visual Search,
Aks, D. J, (1996) Visual search for size is influenced by a background texture gradient,
Brainard, D. H. , (1997) The Psychophysics Toolbox, Spatial Vision 10,
Braun, (1994) Visual search among items of different salience removal of visual attention mimics a lesion in extrastriate area V4 Journal of Neuroscience,
Brown, L. E, (2002) Feature-specific perceptual processing dissociates action from recognition,
Campbell, F. W, (1996) The effect of orientation on thevisual resolution of gratings,
Campbell,F.W.,, (1968) Application of Fourier Analysis to the visibility of gratings,
Coppola, D. M, (1998) Unequal distribution ofcardinal and oblique contours in ferret visual cortex,
Cumming, B. G, (2002) An unexpected specialization for horizontal disparity in primate primary visual cortex,
Yund, (1982) The orientation and direction selectivity of cells in macaque visual cortex,
Duncan,J.,, (1989) Visual search and a stimulus similarity,
Enns, (1990) Influence of scene-based properties on visual search,
Furmanski, C. S, (2000) An oblique effect in human primary visual cortex,
Hansen, B. C, (2004) A horizontal bias in human visual processing of orientation and its correspondence to the structural components of natural scenes,
Huang, L, (2002) Symmetry detection and visual attention: a "binary- map" hypothesis,
Hubel, (1968) Journal of physiology,
Hubel,D.H.,Wiesel,T.N.,Stryker,M.P, (1978) Anatomical demonstration of orientation columns in macaque monkey,
Kelly, D. M, (2001) Detection of Glass Patterns by Pigeons and Humans: Implication for Differences in Higher-Level Processing,
Kleffner, (199218-36) On the perception of shape from shading,
Li, Peterson, Freeman , (2003) The Oblique Effect: a neural basis in the visual cortex,
Murata. A, Vertical axis awareness in 3d environments,
Nakayama, (1986) Serial and parallel processing of visual feature conjunctions,
Nothdurft, H. C, (1999) Focal attention in visual search,
Oliver, C. N. L, (2003) Attentional guidance by salient feature singletons depends on intertrial contingencies.,
Orban, (1984) Human orientation discrimination tested with long stimuli,
Ostrovsky, Y, (2005) Perceiving illumination inconsistencies in scenes,
PPelli, D. G, (1997) The VideoToolbox software for visual psychophysics Transforming numbers into movies,
Ramachandran,V.S, (1988) Perceiving shape from shading,
Regan, (1986) Periodicity in orientation discrimination and the unconfounding of visual information,
Rensink, R, (2004) The influence of cast shadows on visual search,
Ruxton, G. E, (2004) What, if anything, is the adaptive function of countershading? ,
Sireteanu, R., & Rettenbach R , (1995) Perceptual learning in visual search: Fast, enduring, but non-specific. ,
Snowden, R. J, (1998) Texture segregation and visual search: A comparison of the effects of random variations along irrelevant dimensions.,
Sun, J. Y, (1996) Preattentive Percetion of Elementary Three-Dimensional Shapes,
Sun, J. Y, (1998) Where is the Sun?,
Tomonaga, M, (1998) Perception of shape from shading in chimpanzees(Pan troglodytes) and humans(Homo sapiens).,
A, (1986) Features and objects in visual processing,
Treisman,A.,, (1980) A feature integration theory of attention,
Treisman,A, (1988) Feature analysis in early vision:Evidence from search asymmetries,
A, (1985) A diagnostic for preattentive processing of separable features Journal of Experimental Psychology,
Wolfe, J. M, (2003) Changing Your Mind: On the Contribution of Top-Down and Bottom-up Guidance in Visual Search for Feature Singletons.,