Parallel versus serial processing in visual search: further evidence from subadditive effects of visual quality.
The authors propose a diagnostic for distinguishing between serial and parallel processing in visual search; it is based on testing for subadditive effects of a within-trial visual quality manipulation on target-absent trials. It was evaluated in 2 experiments wherein parallel and serial processing might be expected on the basis of previous work and was then applied to a more uncertain situation in a third experiment. The diagnostic indicates parallel processing of stimuli that differ from each other on a featural basis (Xs and Os) and canonical letters that differ in line arrangement (Ts and Ls) but serial processing when Ts and Ls are randomly rotated. These results form a coherent pattern that is understandable in terms of the literature on visual search, and thus they suggest that the diagnostic may be a useful addition to the methodology used to distinguish between serial and parallel processes.
Egeth
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H
Department of Psychology, Johns Hopkins University, Baltimore, Maryland 21218.
Dagenbach
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D
D000328:Adult; D001288:Attention; D004193:Discrimination Learning; D006801:Humans; D010364:Pattern Recognition, Visual; D011930:Reaction Time; D012691:Serial Learning