Chambers Alison, Johnston Alan, Roach Neil W
Visual Neuroscience Group, School of Psychology, The University of Nottingham, Nottingham, UK.
J Vis. 2018 Mar 1;18(3):12. doi: 10.1167/18.3.12.
It has recently been shown that adapting to a densely textured stimulus alters the perception of visual space, such that the distance between two points subsequently presented in the adapted region appears reduced (Hisakata, Nishida, & Johnston, 2016). We asked whether this form of adaptation-induced spatial compression alters visual crowding. To address this question, we first adapted observers to a dynamic dot texture presented within an annular region surrounding the test location. Following adaptation, observers perceived a test array comprised of multiple oriented dot dipoles as spatially compressed, resulting in an overall reduction in perceived size. We then tested to what extent this spatial compression influences crowding by measuring orientation discrimination of a single dipole flanked by randomly oriented dipoles across a range of separations. Following adaptation, we found that the magnitude of crowding was predicted by the physical rather than perceptual separation between center and flanking dipoles. These findings contrast with previous studies in which crowding has been shown to increase when motion-induced position shifts act to reduce apparent separation (Dakin, Greenwood, Carlson, & Bex, 2011; Maus, Fischer, & Whitney, 2011).
最近的研究表明，适应密集纹理刺激会改变视觉空间的感知，使得随后呈现在适应区域内的两点之间的距离看起来缩短了（久方、西田和约翰斯顿，2016年）。我们研究了这种适应诱导的空间压缩是否会改变视觉拥挤现象。为了解决这个问题，我们首先让观察者适应在测试位置周围的环形区域内呈现的动态点纹理。适应之后，观察者将由多个定向点偶极子组成的测试阵列感知为空间压缩，从而导致感知大小整体减小。然后，我们通过测量在一系列间隔下，由随机定向的偶极子包围的单个偶极子的方向辨别能力，来测试这种空间压缩在多大程度上影响拥挤现象。适应之后，我们发现拥挤程度是由中心偶极子和侧翼偶极子之间的物理距离而非感知距离预测的。这些发现与之前的研究形成对比，在之前的研究中，当运动诱导的位置偏移起到减少表观距离的作用时，拥挤现象会增加（达金、格林伍德、卡尔森和贝克斯，2011年；毛斯、菲舍尔和惠特尼，2011年）。
