Figure 2.

(A) Experimental procedure. (B) Accuracy in detecting the target when the search display is a square array. (C) Performance in detecting the absence of the target for the search task. (D) Reaction time in detecting the absence of the target for the search task. There is a main effect of the feature and conjunction conditions on performance (p < 0.01). Note: For illustration purposes, the stimuli shown in this figure are of higher contrast than those used in the experiment.