感数——它能告诉我们什么?

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

Subitizing, What Can It Tell Us

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