Department of Psychology, University of North Carolina Wilmington, 601 South College Road, Wilmington, NC 28403-5612, USA.
J Exp Psychol Learn Mem Cogn. 2010 Nov;36(6):1389-98. doi: 10.1037/a0020212.
Participants' reaction times (RTs) in numerical judgment tasks in which one must determine which of 2 numbers is greater generally follow a monotonically decreasing function of the numerical distance between the two presented numbers. Here, I present 3 experiments in which the relative influences of numerical distance and physical similarity are assessed in just such a task using integers and decimals as stimuli. The data reveal that numerical distance is the primary feature controlling participants' RTs when integers are presented. However, the physical similarity between the decade place of the standard and the probe is the primary feature controlling participants' RTs when decimals are presented. I conclude that the unique qualities of decimals do not lend themselves to share the place-coding representation of integers, thus a direct retrieval mechanism for judging the relative quantity of decimals has developed.
参与者在数字判断任务中的反应时间（RT）通常遵循呈现的两个数字之间的数值距离的单调递减函数。在这里，我提出了 3 个实验，在这个任务中，使用整数和小数作为刺激来评估数值距离和物理相似性的相对影响。数据显示，当呈现整数时，数值距离是控制参与者 RT 的主要特征。然而，当呈现小数时，标准和探针的十进制位置之间的物理相似性是控制参与者 RT 的主要特征。我得出结论，小数的独特性质不适合共享整数的位置编码表示，因此已经开发出一种用于判断小数相对数量的直接检索机制。
