The study of visual illusions has captured the attention of comparative psychologists since the last century, given the unquestionable advantage of investigating complex perceptual mechanisms with relatively simple visual patterns. To date, the observation of animal behavior in the presence of visual illusions has been largely confined to mammal and bird studies. Recently, there has been increasing interest in investigating fish, too. The attention has been particularly focused on guppies, redtail splitfin and bamboo sharks. Overall, the tested species were shown to experience a human-like perception of different illusory phenomena involving size, number, motion, brightness estimation and illusory contours. However, in some cases, no illusory effects, or evidence for a reverse illusion, were also reported. Here, we review the current state of the art in this field. We conclude that a wider investigation of visual illusions in fish is fundamental to form a broader comprehension of perceptual systems of vertebrates. Furthermore, we believe that this type of investigation could help us to address general important issues in perceptual studies, such as the role of ecology in shaping perceptual systems, the existence of interindividual variability in the visual perception of nonhuman species and the role of cortical activity in the emergence of visual illusions.

中文翻译：

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一切也都在水面下主观：鱼的视觉错觉

自从上个世纪以来，对视觉幻觉的研究就引起了比较心理学家的关注，因为利用相对简单的视觉模式研究复杂的感知机制具有无可置疑的优势。迄今为止，在存在视觉幻觉的情况下对动物行为的观察主要限于哺乳动物和鸟类研究。近来，对鱼类的研究也越来越引起人们的兴趣。注意力特别集中在孔雀鱼，红尾tail和竹鲨上。总体而言，测试物种显示出对不同幻觉现象的类人感知，包括大小，数量，运动，亮度估计和幻觉轮廓。但是，在某些情况下，也没有报道任何幻觉效果或反向幻觉的证据。这里，我们回顾了该领域的最新技术。我们得出结论，对鱼类视觉错觉进行更广泛的研究对于形成对脊椎动物感知系统的更广泛理解至关重要。此外，我们认为这种类型的研究可以帮助我们解决感知研究中的一般性重要问题，例如生态学在塑造感知系统中的作用，个体在非人类物种的视觉感知中存在个体差异以及皮层活动的作用在视觉幻象的出现。