Sovrano Valeria Anna, Albertazzi Liliana, Rosa Salva Orsola
Center for Mind/Brain Sciences (CIMeC), University of Trento, C.so Bettini 31, 38068, Rovereto, Trento, Italy,
Anim Cogn. 2015 Mar;18(2):533-42. doi: 10.1007/s10071-014-0821-5. Epub 2014 Nov 21.
The tendency of fish to perceive the Ebbinghaus illusion was investigated. Redtail splitfins (Xenotoca eiseni, family Goodeidae) were trained to discriminate between two disks of different sizes. Then, fish were presented with two disks of the same size surrounded by disks of large or small size (inducers) arranged to produce the impression (to a human observer) of two disks of different sizes (in the Ebbinghaus illusion, a central disk surrounded by small inducers appears bigger than an identical one surrounded by large inducers). Fish chose the stimulus that, on the basis of a perception of the Ebbinghaus illusion, appeared deceptively larger or smaller, consistent with the condition of training. These results demonstrate that redtail splitfins tend to perceive this particular illusion. The results are discussed with reference to other related illusions that have been recently observed to be experienced by fish (such as the Navon effect), and with regard to their possible evolutionary implications.
对鱼类感知艾宾浩斯错觉的倾向进行了研究。红尾裂鳍鱼（Xenotoca eiseni，古氏鱼科）经过训练，以区分两个不同大小的圆盘。然后，向鱼类展示两个相同大小的圆盘，其周围环绕着大或小尺寸的圆盘（诱导物），这些诱导物的排列方式会给（人类观察者）造成两个不同大小圆盘的印象（在艾宾浩斯错觉中，被小诱导物包围的中央圆盘看起来比被大诱导物包围的相同圆盘更大）。鱼类会根据对艾宾浩斯错觉的感知，选择看似欺骗性地更大或更小的刺激，这与训练条件一致。这些结果表明，红尾裂鳍鱼倾向于感知这种特定的错觉。结合最近观察到鱼类也会经历的其他相关错觉（如纳冯效应）以及它们可能的进化意义，对这些结果进行了讨论。
