Boles David B, Phillips Jeffrey B, Givens Somer M
Department of psychology, University of Alabama, Tuscaloosa, Alabama 35405, USA.
Percept Psychophys. 2007 Aug;69(6):913-22. doi: 10.3758/bf03193928.
In two studies, we found that dot enumeration tasks resulted in shallow-sloped response time (RT) functions for displays of 1-4 dots and steep-sloped functions for displays of 5-8 dots, replicating results implicating subitizing and counting processes for low and high ranges of dots, respectively. Extracting number from a specific type of bar graph within the same numerical range produced a shallow-sloped but scallop-shaped RT function. Factor analysis confirmed two independent subranges for dots, but all bar graph values defined a unitary factor. Significantly, factor scores and asymmetries both showed correlations of bar graph recognition to dot subitizing but not to dot counting, strongly suggesting that subitizing was used in both enumeration of low numbers of dots and bar graph recognition. According to these results, subitizing appears to be a nonverbal process operating flexibly in either additive or subtractive fashion on analog quantities having spatial extent, a conclusion consistent with a fast-counting model of subitizing but not with other models of the subitizing process.
在两项研究中，我们发现，对于1至4个点的显示，点计数任务产生了斜率较浅的反应时间（RT）函数，而对于5至8个点的显示，则产生了斜率较陡的函数，这重复了分别暗示低点数范围和高点数范围的即时计数和计数过程的结果。在相同数值范围内从特定类型的条形图中提取数字产生了一个斜率较浅但呈扇形的RT函数。因子分析证实了点的两个独立子范围，但所有条形图值定义了一个单一因子。值得注意的是，因子得分和不对称性均显示条形图识别与点即时计数相关，但与点计数无关，这强烈表明即时计数在低点数枚举和条形图识别中均被使用。根据这些结果，即时计数似乎是一个非语言过程，以加法或减法方式灵活地作用于具有空间范围的模拟量，这一结论与即时计数的快速计数模型一致，但与即时计数过程的其他模型不一致。
