数量表征是人类数学能力的基础,数量表征研究中的一个争论焦点在于是否存在两种不同的数量表征系统:对小数的精确表征系统和对大教的近似表征系统。通过综述不同研究领域对数量表征的研究,总结了支持两种表征系统分离的证据:对1~3范围内小数的表征受数量大小的限制,基于指向物体本身的注意,更依赖于物体的知觉特征,对物体及其数量进行精确表征;而对4以上的数量的近似表征系统则受韦伯定律的限制,基于指向数量的模拟幅度的表征,而不依赖单个物体的知觉特征,是对数量的近似的、心理的表征。fMRI、PET和ERP的脑戍像研究结果迄今尚无定论,但认知神经科学研究的深入开展将最终阐明数量表征的机制。
Numerical representation is the basis of mathematical abilities. A hot topic about numerical representation is whether there are two distinct numerical representation systems: the small precise number system and the large approximate number system. The article reviewed researches on numerical representations in different fields, and summarized evidences supporting the dissociation between the two systems. Numerical representation within the range of 1-3 had a set-size signature was proposed to base on attention to objects themselves per se. Therefore it was sensitive to perceptive properties of objects, and was precise representations about numerosities. While numerical representation for numbers above 4 had a Weber ratio signature. It was suggested to base on analog magnitudes, and was approximate representations of numerosities. However, evidences from the brain imaging field had not gained agreement on this issue. At last, the article brought forth the potential questions about the two basic numerical representation hypothesis.