Cave Kyle R, Chen Zhe
Department of Psychological and Brain Sciences, University of Massachusetts, Tobin Hall, 135 Hicks Way, Amherst, MA, 01003, USA.
Department of Psychology, University of Canterbury, Christchurch, New Zealand.
Atten Percept Psychophys. 2017 Nov;79(8):2354-2375. doi: 10.3758/s13414-017-1405-7.
A number of studies have shown that two stimuli appearing successively at the same spatial location are more likely to be perceived as the same, even though location is irrelevant to the task. This bias to respond "same" when stimuli are at the same location is termed spatial congruency bias. The experiments reported here demonstrate that the spatial congruency bias extends to letter strings: Participants tend to respond "same" when comparing two strings appearing successively at the same location. This bias may arise because successive stimuli at the same location are more likely to be perceived as a single object. Bias is also affected by the nature of the comparison task. We show that if letters must be compared individually (analytical comparison), there is a bias to respond "different," but if letter strings are compared as unified wholes (holistic comparison), there is no bias or a bias to respond "same." This analytical bias is apparently separate from the spatial congruency bias. It appears whether the task requires localization of differences between strings, or counting the number of differences, or ignoring differences in some parts of the stimuli while attending to others. All of these analytical comparison tasks require that letters be selected individually, and the analytical bias may reflect difficulty in preventing interference from neighboring letters in this selection process. Each type of bias reflects a different aspect of visual processing, and both can be measured to probe how processing changes across different tasks.
多项研究表明，即使位置与任务无关，在同一空间位置相继出现的两种刺激也更有可能被视为相同的刺激。当刺激处于相同位置时，这种倾向于回答“相同”的偏差被称为空间一致性偏差。此处报道的实验表明，空间一致性偏差延伸至字母串：参与者在比较相继出现在相同位置的两个字符串时，倾向于回答“相同”。这种偏差可能是因为在相同位置的相继刺激更有可能被视为单个对象。偏差也受比较任务性质的影响。我们表明，如果必须逐个比较字母（分析性比较），则存在回答“不同”的偏差，但如果将字母串作为统一整体进行比较（整体性比较），则不存在偏差或存在回答“相同”的偏差。这种分析性偏差显然与空间一致性偏差不同。无论任务是要求定位字符串之间的差异、计算差异数量，还是在关注刺激的某些部分时忽略其他部分的差异，它都会出现。所有这些分析性比较任务都要求逐个选择字母，并且分析性偏差可能反映了在该选择过程中防止来自相邻字母干扰的困难。每种偏差都反映了视觉处理的不同方面，并且两者都可以进行测量，以探究处理过程在不同任务中的变化情况。
