Mareschal I, Clifford C W G
School of Psychology & Australian Centre of Excellence in Vision Science, The University of Sydney, Sydney, New South Wales, Australia.
J Vis. 2013 May 3;13(6):2. doi: 10.1167/13.6.2.
Contextual effects are ubiquitous in vision and provide a means for detectors with localized receptive fields to encode global properties of a stimulus. Although the nature of the neural connections is complex, the majority of evidence supports the Gestalt idea of collinearity; interactions are greatest when the target and surround orientations are spatially aligned to form a contour. Here we create a novel stimulus that simultaneously probes all areas around a detector to determine which spatial positions influence perception in human observers. We find that the surrounding spatial areas that contribute most to contextual effects for our perception of orientation and motion are not confined to a specific location. Rather our results reveal that human perception displays some interobserver variability in the weighting of detector interactions that is largely independent of collinear structure. We propose that these more extensive surround stimuli reveal how complex visual structure may modulate performance in a manner that is not easily predictable using more conventional stimuli.
上下文效应在视觉中无处不在，并为具有局部感受野的探测器提供了一种编码刺激全局属性的方式。尽管神经连接的性质很复杂，但大多数证据支持格式塔的共线性观点；当目标和周围方向在空间上对齐以形成轮廓时，相互作用最强。在这里，我们创建了一种新颖的刺激，同时探测探测器周围的所有区域，以确定哪些空间位置会影响人类观察者的感知。我们发现，对我们的方向和运动感知的上下文效应贡献最大的周围空间区域并不局限于特定位置。相反，我们的结果表明，人类感知在探测器相互作用的权重方面表现出一些观察者间的变异性，这在很大程度上与共线结构无关。我们提出，这些更广泛的周围刺激揭示了复杂的视觉结构如何以一种使用更传统刺激难以预测的方式调节性能。
