Abstract

This article explores the effects-of perceptual grouping on search for targets defined by separate features or by conjunction of features. Treisman and Gelade proposed a feature-integration theory of attention, which claims that in the absence of prior knowledge, the separable features of objects are correctly combined only when focused attention is directed to each item in turn. If items are preattentively grouped, however, attention may be directed to groups rather than to single items whenever no recombination of features within a group could generate an illusory target. This prediction is confirmed: In search for conjunctions, subjects appear to scan serially between groups rather than items. The scanning rate shows little effect of the spatial density of distractors, suggesting that it reflects serial fixations of attention rather than eye movements. Search for features, on the other hand, appears to be independent of perceptual grouping, suggesting that features are detected preattentively. A conjunction target can be camouflaged at the preattentive level by placing it at the boundary between two adjacent groups, each of which shares one of its features. This suggests that preattentive

Citations

235	Cognitive psychology - Neisser - 1967
219	A feature integration theory of attention - Treisman, Gelade - 1980
211	Controlled and automatic human information processing: II. Perceptual learning, automatic attending, and a general theory - Shiffrin, Schneider - 1977
108	Untersuchungen zur Lehre von der Gestalt. Psychol Forch 1923, 4:301-350. Translated by Ellis WD, A Source Book of Gestalt Psychology, London: Routledge & Kegan Paul; 1938: 78. Publish with BioMed Central and every scientist can read your work free of char - Wertheimer
86	Illusory conjunctions in the perception of objects - Treisman, Schmidt - 1982
47	Perceptual Organization and Attention - Kahneman, Henik - 1981
43	Experiments in the visual perception of texture - Julesz - 1976
26	Effect of orientation and of shape similarity on perceptual grouping - Beck - 1966
20	Principles of feature integration in visual perception - Prinzmetal - 1981
13	What variables produce similarity grouping - Olson, Attneave - 1970
11	Configurational effects in visual information processing - Banks, Prinzmetal - 1976
11	On perceptual analyzers underlying visual texture discrimination: Part II - Caelli, Julesz, et al. - 1978
10	Selective attention and stimulus integration - Treisman, Sykes, et al. - 1977
9	The effects of concentrated and distributed attention on peripheral acuity - Beck, Ambler - 1973
9	Attention and the measurement of perceptual learning - LaBerge
7	Perceptual organization - Kubovy, Pomerantz - 1981
6	Visual search through color displays: Effects of target-background similarity and background uniformity - FARMER, TAYLOR - 1980
5	Some results on the identifiability of parallel and serial processes - Townsend - 1972
2	On the limits of Fourier decomposition in visual texture perception. Perception - Julesz, Caelli - 1979
1	The influence of selective attention in peripheral and foveal vision. Perception & Psychophysics - Ambler, Finklea - 1976
1	A foveal discriminability difference for one vs. four letters - Ambler, Keel, et al.
1	Similarity grouping and perceptual discriminability under uncertainty - Beck
1	Strategies of information processing - Underwood - 1978
1	Spatial nonlinearities in the instantaneous perception of textures with identical power spectra - American - 1975
1	Eds.), The psychology of vision - Longuet-Higgins, Sutherland - 1980
1	Attention and performance VI - Domic - 1977
1	Per- ANNE TREISMAN ception of wholes and of their component parts: Some configural superiority effects - Pomerantz, Sager, et al.