2007 Summer Institute: Visual Perception and Cognition Conference

Yuhong Jiang
Harvard University

Cognitive Limitations in Visual Perception and Memory

     Human vision is stunningly powerful in some respects yet surprisingly limited in others. We can recognize an object or a face in a single glimpse and type 70 words per minute, yet we cannot hold more than a few objects at a time in visual working memory or split our attention to several locations. Attention and working memory impose major capacity limitations in visual processing. What sets the capacity limit of attention and working memory? Conventional wisdom says that attention is limited in the number of foci, and working memory is limited in slots with the number of slots inversely related to object complexity.

      I will show that these views are false. Using multiple object tracking, we show that attention is severely limited in its ability to maintain adjacent attentional foci. Using change detection tasks, we show that visual working memory is filled up less quickly by complex objects such as faces than by simple objects such as line orientations. Our study sheds new lights on cognitive limitations in visual perception and memory.