Corbett Jennifer E, Wurnitsch Nicole, Schwartz Alex, Whitney David
Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy.
Department of Psychology, University of California, Berkeley, CA, USA.
Vis cogn. 2012 Feb 1;20(2). doi: 10.1080/13506285.2012.657261.
The visual system rapidly represents the mean size of sets of objects. Here, we investigated whether mean size is explicitly encoded by the visual system, along a single dimension like texture, numerosity, and other visual dimensions susceptible to adaptation. Observers adapted to two sets of dots with different mean sizes, presented simultaneously in opposite visual fields. After adaptation, two test patches replaced the adapting dot sets, and participants judged which test appeared to have the larger average dot diameter. They generally perceived the test that replaced the smaller mean size adapting set as being larger than the test that replaced the larger adapting set. This differential aftereffect held for single test dots (Experiment 2) and high-pass filtered displays (Experiment 3), and changed systematically as a function of the variance of the adapting dot sets (Experiment 4), providing additional support that mean size is adaptable, and therefore explicitly encoded dimension of visual scenes.
视觉系统能快速呈现物体集合的平均大小。在此，我们研究了平均大小是否像纹理、数量以及其他易受适应影响的视觉维度一样，沿着单一维度由视觉系统明确编码。观察者适应了同时呈现于相对视野中的两组平均大小不同的点。适应后，两个测试斑块取代了适应点集，参与者判断哪个测试斑块的平均点直径看起来更大。他们通常会觉得取代较小平均大小适应集的测试斑块比取代较大适应集的测试斑块更大。这种差异后效在单个测试点（实验2）和高通滤波显示（实验3）中都存在，并且会随着适应点集的方差系统地变化（实验4），这进一步支持了平均大小是可适应的，因此是视觉场景的明确编码维度。
