Chapman Craig S, Gallivan Jason P, Wood Daniel K, Milne Jennifer L, Ansari Daniel, Culham Jody C, Goodale Melvyn A
Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada.
J Vis. 2014 Mar 26;14(3):30. doi: 10.1167/14.3.30.
Symbolic numbers (e.g., "2") acquire their meaning by becoming linked to the core nonsymbolic quantities they represent (e.g., two items). However, the extent to which symbolic and nonsymbolic information converges onto the same internal core representations of quantity remains a point of considerable debate. As nearly all previous work on this topic has employed perceptual tasks requiring the conscious reporting of numerical magnitudes, here we question the extent to which numerical processing via the visual-motor system might shed further light on the fundamental basis of how different number formats are encoded. We show, using a rapid reaching task and a detailed analysis of initial arm trajectories, that there are key differences in how the quantity information extracted from symbolic Arabic numerals and nonsymbolic collections of discrete items are used to guide action planning. In particular, we found that the magnitude derived from discrete dots resulted in movements being biased by an amount directly proportional to the actual quantities presented whereas the magnitude derived from numerals resulted in movements being biased only by the relative (e.g., larger than) quantities presented. In addition, we found that initial motor plans were more sensitive to changes in numerical quantity within small (1-3) than large (5-15) number ranges, irrespective of their format (dots or numerals). In light of previous work, our visual-motor results clearly show that the processing of numerical quantity information is both format and magnitude dependent.
符号数字（例如“2”）通过与它们所代表的核心非符号数量（例如两个物品）建立联系而获得其意义。然而，符号信息和非符号信息在多大程度上汇聚到相同的数量内部核心表征上，仍然是一个备受争议的问题。由于此前几乎所有关于该主题的研究都采用了需要有意识报告数字大小的感知任务，在此我们探讨通过视觉 - 运动系统进行的数字处理在何种程度上可能会进一步揭示不同数字格式编码的基本基础。我们通过一项快速伸手任务以及对初始手臂轨迹的详细分析表明，从符号阿拉伯数字和离散物品的非符号集合中提取的数量信息在用于指导动作规划方面存在关键差异。具体而言，我们发现从离散点得出的数量大小会导致动作偏差量与所呈现的实际数量成正比，而从数字得出的数量大小仅会导致动作偏差量与所呈现的相对数量（例如大于）有关。此外，我们发现无论格式是点还是数字，初始运动计划对小数字范围（1 - 3）内的数量变化比大数字范围（5 - 15）内的数量变化更敏感。根据先前的研究，我们的视觉 - 运动结果清楚地表明，数字数量信息的处理既依赖于格式也依赖于数量大小。
