Document Detail

The role of features in preattentive vision: comparison of orientation, motion and color cues.
MedLine Citation:
PMID:  8249312     Owner:  NLM     Status:  MEDLINE    
Arrays of lines or blobs were used to investigate the role of features vs feature contrast in preattentive vision. This study continues earlier work on orientation cues and extends it into the dimensions of motion and color. Tests were performed on patterns displaying continuous feature gradients, i.e. continuous variation, from element to element, in either line orientation, direction of motion, or color. In different series of experiments, the following four aspects of visual perception were investigated: (i) detection of a salient target ("odd man out" paradigm), (ii) segmentation of texture fields, (iii) search strategies for given targets, and (iv) figure-ground discrimination by grouping. Features were, in general, not found to play an important role in these tasks and performance was instead related to feature contrast. Only in the case of color did performance also depend upon hue, i.e. feature properties themselves. Whereas in all dimensions tested pop-out ("saliency") and segmentation were obtained from target or border elements whose local feature contrast was well above the level of variation elsewhere in the pattern, performance in the two latter tasks differed between orientation, motion, and color. In search, orientation targets were detected quickly when sufficiently distinct from their neighbors, but were apparently searched for serially if feature contrast was similar to that of other elements nearby. Color targets, however, were always detected fast in these patterns, independently of local feature contrast. Also, the perceived grouping of orientation or motion defined targets depended only on local feature contrast and not on the similarity of target elements. In fact, figures of dissimilar elements were seen as easily as figures of similar elements, indicating that, in these dimensions, stimulus coherence is not essential for the discrimination of figure and ground. For color, however, figures made up of the same targets were always seen slightly better than figures composed of different colors.
H C Nothdurft
Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Vision research     Volume:  33     ISSN:  0042-6989     ISO Abbreviation:  Vision Res.     Publication Date:  1993 Sep 
Date Detail:
Created Date:  1993-12-30     Completed Date:  1993-12-30     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0417402     Medline TA:  Vision Res     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  1937-58     Citation Subset:  IM; S    
Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
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MeSH Terms
Color Perception / physiology*
Contrast Sensitivity / physiology
Discrimination (Psychology) / physiology
Motion Perception / physiology*
Pattern Recognition, Visual / physiology*
Reaction Time / physiology

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