Data from: Perception of contextual size illusions by honeybees in restricted and unrestricted viewing conditions

How different visual systems process images and make perceptual errors can inform us about cognitive and visual processes. One of the strongest geometric errors in perception is a misperception of size depending on the size of surrounding objects, known as the Ebbinghaus or Titchener illusion. The ability to perceive the Ebbinghaus illusion appears to vary dramatically among vertebrate species, and even populations, but this may depend on whether the viewing distance is restricted. We tested whether honeybees perceive contextual size illusions, and whether errors in perception of size differed under restricted and unrestricted viewing conditions. When the viewing distance was unrestricted, there was an effect of context on size perception and thus, similar to humans, honeybees perceived contrast size illusions. However, when the viewing distance was restricted, bees were able to judge absolute size accurately and did not succumb to visual illusions, despite differing contextual information. Our results show that accurate size perception depends on viewing conditions, and thus may explain the wide variation in previously reported findings across species. These results provide insight into the evolution of visual mechanisms across vertebrate and invertebrate taxa, and suggest convergent evolution of a visual processing solution.不同视觉系统如何处理图像并产生知觉误差，这一研究可为认知与视觉加工机制提供重要启示。知觉领域中最显著的几何误差之一，是受周围物体大小影响而产生的尺寸知觉偏差，这类现象被称为埃宾浩斯错觉（Ebbinghaus illusion）或铁钦纳错觉（Titchener illusion）。不同脊椎动物物种甚至同物种的不同种群，对埃宾浩斯错觉的感知能力差异极大，但这种差异可能受观测距离是否受限的影响。本研究测试了蜜蜂是否能感知情境性尺寸错觉，以及在受限与非受限观测条件下，其尺寸知觉误差是否存在差异。当观测距离不受限时，情境会对尺寸知觉产生影响，即蜜蜂与人类相似，会感知到对比性尺寸错觉。但当观测距离受限时，尽管存在不同的情境信息，蜜蜂仍能准确判断绝对尺寸，并未受到视觉错觉的干扰。本研究结果表明，准确的尺寸知觉依赖于观测条件，这或可解释此前不同物种研究中所报道的结果差异。这些研究结果为脊椎动物与无脊椎动物类群的视觉机制演化提供了新的见解，并提示视觉加工策略存在趋同演化现象。