感数--它能告诉我们什么?

Subitizing, What Can It Tell Us?

研究者在列举任务中发现，被试对3个以内项目的报告既快又准确(一般称之为[感数])，而对3个以上项目的报告既慢又容易出错误([计数])，由此他们提出感数和计数属于两种不同性质的加工过程，一系列行为数据的反应时和正确率指标支持了这一假设。此外，最近的脑成像、电生理研究还发现，感数和计数在对注意的需求上同样存在着分离--感数无需注意，只有计数过程才需注意的参与。在此基础上，研究者从不同角度提出了一些解释感数现象的理论。

During the process of enumeration， researchers found that enumeration of three or fewer objects is very fast and accurate (often called [subitizing])， but gets slower and more error prone for more than three items ([counting]). Thereby they suggested that [subitizing] and [counting] are two qualitatively separable processes， a number of behavioral reaction time and accuracy supported their hypothesis. Moreover， recent neruoimage and electrophysiology results showed that [subitizing] and [counting] are also separable in attentional requirements. that is， [subitizing]can happen without attention， while [counting]must rely on attention. Based on these findings， many theories have been proposed to account for subitizing phenomenon.