Helmholtz Institute, Universiteit Utrecht, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Exp Brain Res. 2010 Aug;204(4):525-37. doi: 10.1007/s00221-010-2319-y. Epub 2010 Jun 12.
'Subitizing' refers to fast and accurate judgement of small numerosities, whereas for larger numerosities either counting or estimation are used. Counting is slow and precise, whereas estimation is fast but imprecise. In this study consisting of five experiments we investigated if and how the numerosity judgement process is affected by the relative spacing between the presented numerosities. To this end we let subjects judge the number of dots presented on a screen and recorded their response times. Our results show that subjects switch from counting to estimation if the relative differences between subsequent numerosities are large (a factor of 2), but that numerosity judgement in the subitizing range was still faster. We also show this fast performance for small numerosities only occurred when numerosity information is present. This indicates this is typical for number processing and not magnitude estimation in general. Furthermore, comparison with a previous haptic study suggests similar processing in numerosity judgement through haptics and vision.
“数小”是指对小数量的快速准确判断，而对于较大的数量则使用计数或估计。计数速度慢但精确，而估计速度快但不精确。在这项由五个实验组成的研究中，我们调查了数量判断过程是否以及如何受到呈现数量之间相对间隔的影响。为此，我们让被试判断屏幕上呈现的点数，并记录他们的反应时间。我们的结果表明，如果后续数量之间的相对差异较大（相差 2 倍），被试会从计数切换到估计，但“数小”范围内的数量判断仍然更快。我们还表明，只有在存在数量信息时，小数量才会出现这种快速表现。这表明这是数量处理的典型特征，而不是一般的大小估计。此外，与之前的触觉研究进行比较表明，通过触觉和视觉进行数量判断的处理方式相似。
