Santacà Maria, Granziol Umberto
Department of Biology, University of Padova, Viale Giuseppe Colombo 3 - Via Ugo Bassi 58/B, 35131, Padua, Italy.
Department of General Psychology, University of Padova, Padua, Italy.
Anim Cogn. 2023 Jun;26(3):823-835. doi: 10.1007/s10071-022-01721-6. Epub 2022 Nov 27.
Discriminating between different quantities is an essential ability in daily life that has been demonstrated in a variety of non-human vertebrates. Nonetheless, what drives the estimation of numerosity is not fully understood, as numerosity intrinsically covaries with several other physical characteristics. There is wide debate as to whether the numerical and spatial abilities of vertebrates are processed by a single magnitude system or two different cognitive systems. Adopting a novel approach, we aimed to investigate this issue by assessing the interaction between area size and numerosity, which has never been conceptualized with consideration for subjective experience in non-human animals. We examined whether the same perceptual biases underlying one of the best-known size illusions, the Delboeuf illusion, can be also identified in numerical estimation tasks. We instructed or trained human participants and guppies, small teleost fish, to select a target numerosity (larger or smaller) of squares between two sets that actually differed in their numerosity. Subjects were also presented with illusory trials in which the same numerosity was presented in two different contexts, against a large and a small background, resembling the Delboeuf illusion. In these trials, both humans and fish demonstrated numerical biases in agreement with the perception of the classical version of the Delboeuf illusion, with the array perceived as larger appearing more numerous. Thus, our results support the hypothesis of a single magnitude system, as perceptual biases that influence spatial decisions seem to affect numerosity judgements in the same way.
区分不同数量是日常生活中的一项基本能力，这已在多种非人类脊椎动物中得到证实。然而，驱动数量估计的因素尚未完全明确，因为数量本质上与其他几个物理特征相互关联。关于脊椎动物的数字和空间能力是由单一量级系统还是两个不同的认知系统处理，存在广泛的争论。我们采用一种新方法，旨在通过评估面积大小和数量之间的相互作用来研究这个问题，而在非人类动物中，从未结合主观体验来对这种相互作用进行概念化。我们研究了在数字估计任务中，是否也能识别出最著名的大小错觉之一——德勃夫错觉背后相同的感知偏差。我们指导或训练人类参与者和孔雀鱼（一种小型硬骨鱼），从两组实际数量不同的方块中选择目标数量（更大或更小）。还向受试者呈现了错觉试验，其中相同数量的方块在两种不同背景下呈现，一种是大背景，一种是小背景，类似于德勃夫错觉。在这些试验中，人类和鱼都表现出与经典版本德勃夫错觉的感知一致的数字偏差，即被视为更大的阵列看起来数量更多。因此，我们的结果支持单一量级系统的假设，因为影响空间决策的感知偏差似乎以相同方式影响数量判断。
