Leibovich Tali, Henik Avishai
a Department of Cognitive and Brain Sciences , Ben-Gurion University of the Negev , Beer-Sheva , Israel.
Q J Exp Psychol (Hove). 2014 May;67(5):899-917. doi: 10.1080/17470218.2013.837940. Epub 2013 Sep 27.
The approximate number system (ANS) theory suggests that all magnitudes, discrete (i.e., number of items) or continuous (i.e., size, density, etc.), are processed by a shared system and comply with Weber's law. The current study reexamined this notion by comparing performance in discrete (comparing numerosities of dot arrays) and continuous (comparisons of area of squares) tasks. We found that: (a) threshold of discrimination was higher for continuous than for discrete comparisons; (b) while performance in the discrete task complied with Weber's law, performance in the continuous task violated it; and (c) performance in the discrete task was influenced by continuous properties (e.g., dot density, dot cumulative area) of the dot array that were not predictive of numerosities or task relevant. Therefore, we propose that the magnitude processing system (MPS) is actually divided into separate (yet interactive) systems for discrete and continuous magnitude processing. Further subdivisions are discussed. We argue that cooperation between these systems results in a holistic comparison of magnitudes, one that takes into account continuous properties in addition to numerosities. Considering the MPS as two systems opens the door to new and important questions that shed light on both normal and impaired development of the numerical system.
近似数系统（ANS）理论认为，所有量级，无论是离散的（即项目数量）还是连续的（即大小、密度等），都由一个共享系统进行处理，并符合韦伯定律。当前的研究通过比较离散任务（比较点阵的数量）和连续任务（比较正方形面积）中的表现，重新审视了这一概念。我们发现：（a）连续比较的辨别阈值高于离散比较；（b）虽然离散任务的表现符合韦伯定律，但连续任务的表现却与之相悖；（c）离散任务的表现受到点阵的连续属性（如点密度、点累积面积）的影响，而这些属性与数量或任务无关。因此，我们提出量级处理系统（MPS）实际上分为用于离散和连续量级处理的独立（但相互作用）系统。文中还讨论了进一步的细分。我们认为，这些系统之间的协作会导致对量级进行整体比较，这种比较除了考虑数量外，还会兼顾连续属性。将MPS视为两个系统，为揭示数字系统正常和受损发展情况的新的重要问题打开了大门。
