Shulman G L
Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110.
Q J Exp Psychol A. 1992 Nov;45(4):529-46. doi: 10.1080/14640749208401332.
A test circle surrounded by smaller context circles appears larger if presented in isolation, whereas a test circle surrounded by large context circles is seen as smaller than in isolation. Two experiments are reported indicating that this phenomenon, the Ebbinghaus illusion, depends on whether subjects are attending to the context circles. Subjects first saw a reference circle and then a briefly presented (150 msec) test circle. Their task was to determine whether the test circle was larger or smaller than the reference. The test circle was surrounded by smaller context circles of one colour arrayed along a horizontal axis centred on the test, and larger context circles of a different colour arrayed along a vertical axis centred on the test. Subjects judged both the size of the test and the colours of either the small or large context circles. Perceived test size changed systematically, depending on which context circles were task-relevant.
一个被较小的背景圆圈环绕的测试圆圈如果单独呈现会显得更大，而一个被大背景圆圈环绕的测试圆圈则会被视为比单独呈现时更小。报告了两项实验，表明这种现象，即艾宾浩斯错觉，取决于受试者是否关注背景圆圈。受试者首先看到一个参照圆圈，然后是一个短暂呈现（150毫秒）的测试圆圈。他们的任务是确定测试圆圈比参照圆圈大还是小。测试圆圈被沿以测试为中心的水平轴排列的一种颜色的较小背景圆圈以及沿以测试为中心的垂直轴排列的另一种颜色的较大背景圆圈所环绕。受试者既要判断测试圆圈的大小，也要判断小背景圆圈或大背景圆圈的颜色。根据哪些背景圆圈与任务相关，测试圆圈的感知大小会有系统性变化。
