Response Times in experiment 1. Shown are the response times in target present trials (top) and target absent trials (bottom) in both cue types; positive (blue) and negative (red). Dots denote mean values for correct answers of each individual and number of items, lines the means for each group. The slopes of linear fits were determined for target absent trials for set sizes 6–24, where linearity seems to be satisfied. All participants exhibited a higher slope in “negative cue” (mean value 236ms/item) versus “positive cue” (mean value 158ms/item) condition.