University of Stirling, Department of Psychology, Stirling, FK9 4LA, Scotland, United Kingdom.
McGill Vision Research, Department of Ophthalmology, McGill University, Montreal, Qc, Canada.
Sci Rep. 2017 Feb 23;7:43274. doi: 10.1038/srep43274.
In biological vision, contextual modulation refers to the influence of a surround pattern on either the perception of, or the neural responses to, a target pattern. One studied form of contextual modulation deals with the effect of a surround texture on the perceived shape of a contour, in the context of the phenomenon known as the shape aftereffect. In the shape aftereffect, prolonged viewing, or adaptation to a particular contour's shape causes a shift in the perceived shape of a subsequently viewed contour. Shape aftereffects are suppressed when the adaptor contour is surrounded by a texture of similarly-shaped contours, a surprising result given that the surround contours are all potential adaptors. Here we determine the motion and temporal properties of this form of contextual modulation. We varied the relative motion directions, speeds and temporal phases between the central adaptor contour and the surround texture and measured for each manipulation the degree to which the shape aftereffect was suppressed. Results indicate that contextual modulation of shape processing is selective to motion direction, temporal frequency and temporal phase. These selectivities are consistent with one aim of vision being to segregate contours that define objects from those that form textured surfaces.
在生物视觉中，语境调制是指周围模式对目标模式的感知或神经反应的影响。语境调制的一种研究形式涉及到周围纹理对轮廓感知形状的影响，这是一种被称为形状后效的现象的一部分。在形状后效中，长时间观察或适应特定轮廓的形状会导致随后观察到的轮廓的感知形状发生变化。当适应器轮廓被具有相似形状的轮廓的纹理包围时，形状后效会被抑制，这是一个令人惊讶的结果，因为周围的轮廓都是潜在的适应器。在这里，我们确定了这种语境调制的运动和时间特性。我们改变了中央适应器轮廓和周围纹理之间的相对运动方向、速度和时间相位，并测量了每种操作对形状后效抑制程度的影响。结果表明，形状处理的语境调制对运动方向、时间频率和时间相位具有选择性。这些选择性与视觉的一个目标一致，即从形成纹理表面的轮廓中分离出定义物体的轮廓。
