Laboratory of Experimental Psychology, Katholieke Universiteit Leuven, Tiensestraat 102, Leuven, Belgium.
J Exp Psychol Gen. 2012 Nov;141(4):642-8. doi: 10.1037/a0026218. Epub 2011 Nov 14.
To date, researchers investigating nonsymbolic number processes devoted little attention to the visual properties of their stimuli. This is unexpected, as nonsymbolic number is defined by its visual characteristics. When number changes, its visual properties change accordingly. In this study, we investigated the influence of different visual properties on nonsymbolic number processes and show that the current assumptions about the relation between number and its visual characteristics are incorrect. Similar to previous studies, we controlled the visual cues: Each visual cue was not predictive of number. Nevertheless, participants showed congruency effects induced by the visual properties of the stimuli. These congruency effects scaled with the number of visual cues manipulated, implicating that people do not extract number from a visual scene independent of its visual cues. Instead, number judgments are based on the integration of information from multiple visual cues. Consequently, current ways to control the visual cues of the number stimuli are insufficient, as they control only a single variable at the time. And, more important, the existence of an approximate number system that can extract number independent of the visual cues appears unlikely. We therefore propose that number judgment is the result of the weighing of several distinct visual cues.
迄今为止，研究非符号数字过程的研究人员很少关注其刺激的视觉属性。这是出乎意料的，因为非符号数字是由其视觉特征定义的。当数字发生变化时，其视觉特征也会相应地发生变化。在这项研究中，我们研究了不同视觉属性对非符号数字过程的影响，并表明当前关于数字与其视觉特征之间关系的假设是不正确的。与之前的研究类似，我们控制了视觉线索：每个视觉线索都不能预测数字。然而，参与者表现出由刺激的视觉属性引起的一致性效应。这些一致性效应与所操纵的视觉线索数量成正比，这表明人们并非独立于其视觉线索从视觉场景中提取数字。相反，数字判断是基于来自多个视觉线索的信息的整合。因此，当前控制数字刺激的视觉线索的方法是不够的，因为它们一次只能控制一个变量。更重要的是，不太可能存在一个可以独立于视觉线索提取数字的近似数字系统。因此，我们提出数字判断是对几个不同视觉线索进行权衡的结果。
