Perspective abstract
Nature Neuroscience , 1129 - 1135 (2008)
Published online: 25 September 2008 | Corrected online: 13 November 2008 | doi:10.1038/nn.2187
There is an Erratum (December 2008) associated with this Perspective
The uncrowded window of object recognition
Denis G Pelli1 & Katharine A Tillman1
Abstract
It is now emerging that vision is usually limited by object spacing rather than size. The visual system recognizes an object by detecting and then combining its features. 'Crowding' occurs when objects are too close together and features from several objects are combined into a jumbled percept. Here, we review the explosion of studies on crowding—in grating discrimination, letter and face recognition, visual search, selective attention, and reading—and find a universal principle, the Bouma law. The critical spacing required to prevent crowding is equal for all objects, although the effect is weaker between dissimilar objects. Furthermore, critical spacing at the cortex is independent of object position, and critical spacing at the visual field is proportional to object distance from fixation. The region where object spacing exceeds critical spacing is the 'uncrowded window'. Observers cannot recognize objects outside of this window and its size limits the speed of reading and search.
- Department of Psychology and Center for Neural Science, New York University, 6 Washington Place, New York, New York 10003, USA.
Correspondence to: Denis G Pelli1 e-mail: denis.pelli@nyu.edu
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
Seeing the forest but not the treesNature Neuroscience News and Views (01 Jul 2001)
Stimulating brain but not mindNature News and Views (26 Sep 1996)
RESEARCH
Compulsory averaging of crowded orientation signals in human visionNature Neuroscience Article (01 Jul 2001)
Interaction Effects in Parafoveal Letter RecognitionNature Letters to Editor (11 Apr 1970)
Attentional resolution and the locus of visual awarenessNature Letters to Editor (26 Sep 1996)

