Nakamura Noriyuki, Fujita Kazuo, Ushitani Tomokazu, Miyata Hiromitsu
Department of Psychology, Graduate School of Letters, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
J Comp Psychol. 2006 Aug;120(3):252-61. doi: 10.1037/0735-7036.120.3.252.
The authors compared perception of the standard and reversed Müller-Lyer figures between pigeons (Columbia livia) and humans (Homo sapiens). In Experiment 1, pigeons learned to classify 6 lengths of target lines into "long" and "short" categories by pecking 2 keys on the monitor, ignoring the 2 brackets so placed that they would not induce an illusion. In the test that followed, all 3 birds chose the "long" key more frequently for the standard Müller-Lyer figures with inward-pointing brackets (><) than for the figures with outward-pointing brackets (<>). The subjects' responses were accountable by neither overall lengths of the figures nor horizontal gaps between the 2 brackets. For the reversed figures, effects of the brackets were absent. These results suggested that the pigeons perceived the standard Müller-Lyer illusion but not the reversed one. Experiment 2 confirmed that humans perceived both types of the illusion. Pigeons and humans may perceive the same illusory figures in different ways.
作者比较了鸽子（家鸽）和人类（智人）对标准及倒置的缪勒-莱尔图形的感知。在实验1中，鸽子通过啄击显示器上的两个按键，学会将6种长度的目标线条分类为“长”和“短”两类，忽略放置的两个括号，因为它们不会产生错觉。在随后的测试中，所有3只鸟对带有向内括号（><）的标准缪勒-莱尔图形选择“长”按键的频率，高于带有向外括号（<>）的图形。受试者的反应既不能用图形的总长度来解释，也不能用两个括号之间的水平间距来解释。对于倒置的图形，括号没有影响。这些结果表明，鸽子能感知标准的缪勒-莱尔错觉，但不能感知倒置的错觉。实验2证实人类能感知这两种错觉。鸽子和人类可能以不同方式感知相同的错觉图形。
