Does Spatial Attention Influence the Severity of Visual Crowding?

The identification of a target in peripheral vision is severely impaired in the presence of nearby distracting information. This phenom- enon is referred to as visual crowding, and it constrains important visual processes, such as object recognition and reading. Although a popular model of crowding attributes perceptual degradation to the compulsory averaging of target and distractor feature values, recent work by Ester, Klee, & Awh (in prep.) suggests that crowding is the result of feature mislocalization and a subsequent “swapping” of target and distractor feature information. Decades of research have shown that when an observer directs attention to the location of a stimulus, perceptual processing of that item is enhanced. Here, we examined the consequences of spatial attention on visual crowding. Our findings show that spatial attention attenuates crowding effects by reducing confusions between target and distractor values. The critical spacing distance for crowding – defined by the largest distance between targets and distractors where crowding is observed – was unaffected by spatial attention. These findings shed light on the basic mechanisms by which visual attention can ameliorate the harmful effects of nearby distractor stimuli.