Search via recursive rejection (SERR): visual search for single and dual form-conjunction targets

Models of visual search that assume spatially serial processing of conjunction stimuli break down when displays contain 2 identical conjunction targets: (a) They fail to account for the slopes of the target-absent reaction time (RT)/display size functions, both when the target-present response requires the detection of only 1 of the 2 targets and when it requires the detection of both targets and (b) under redundant target conditions, the probability of "fast" present RTs is greater than that expected from the independent (serial) processing of the target stimuli. This article shows that G. W. Humphreys and H.J. Müller's (1993) parallel search via recursive rejection (SERR) model can account for human search performance under dual-target conditions. In SERR, simple form conjunctions are coded and grouped (on the basis of their similarity) in a spatially parallel manner, and targets are detected through the activation of a temporary "template" or through the recursive rejection of grouped distractors.