Scolari Miranda, Kohnen Andrew, Barton Brian, Awh Edward
Department of Psychology, University of Oregon, Eugene, OR, USA.
J Vis. 2007 Feb 14;7(2):7.1-23. doi: 10.1167/7.2.7.
Crowding refers to the phenomenon in which nearby distractors impede target processing. This effect is reduced as target-distractor distance increases, and it is eliminated entirely at a distance that is labeled the critical spacing point. Attention, distractor preview, and popout are each known to facilitate processing in crowded displays. Eight experiments examined whether this is accomplished via a reduction in critical spacing. Attention was manipulated via spatial cueing, whereby a peripheral cue elicited a stimulus-driven shift of attention. Distractor preview was examined by manipulating whether the crowding distractors were presented prior to or simultaneous with the target. Popout was examined by manipulating whether there was a salient color difference between the target and distractors. As demonstrated in previous studies, we found robust benefits of spatial cueing, preview, and popout in crowded displays. However, although spatial cueing led to robust improvements in target discrimination, there was no reduction in critical spacing for attended stimuli. By contrast, both preview and popout caused large reductions in critical spacing. These disparate results indicate that attention improves target discrimination in crowded displays in a qualitatively different manner than do the other factors.
拥挤效应是指附近的干扰项妨碍目标处理的现象。随着目标与干扰项距离的增加，这种效应会减弱，并且在一个被标记为临界间距点的距离上会完全消除。已知注意力、干扰项预呈现和突显效应都有助于在拥挤显示中进行处理。八项实验研究了这是否是通过临界间距的减小来实现的。通过空间线索化来操纵注意力，即一个外周线索引发由刺激驱动的注意力转移。通过操纵拥挤干扰项是在目标之前呈现还是与目标同时呈现来研究干扰项预呈现。通过操纵目标与干扰项之间是否存在显著的颜色差异来研究突显效应。正如先前研究所示，我们发现在拥挤显示中空间线索化、预呈现和突显效应都有显著益处。然而，尽管空间线索化导致目标辨别能力有显著提高，但对于被注意的刺激，临界间距并没有减小。相比之下，预呈现和突显效应都导致临界间距大幅减小。这些不同的结果表明，注意力在拥挤显示中提高目标辨别能力的方式与其他因素在性质上有所不同。
