Fig 1.
Experiment 1 search display (A) and trial sequence (B). Targets were either a color singleton or shape singleton, and were cued by a high or low pitched tone at the start of each trial. Participants responded by making a saccade to the target.
Fig 2.
Pupil dilation across the preparation period in Experiment 1.
Pupil dilation was calculated using z-scored pupil area values. Error bands depict standard error of the mean color vs shape difference scores.
Fig 3.
Partial regression plots of linear mixed effects results from Experiments 1–3.
(A)–(C) show accuracy residuals after controlling for all other fixed and random effects plotted against mean dilation for Experiment 1 (A), Experiment 2 (B) and Experiment 3 (C). Accuracy was coded as 0 for incorrect and 1 for correct, and consequently correct and incorrect trial residuals form separate clusters of dots in the scatterplots. (D)–(F) show RT residuals after controlling for all other fixed and random effects plotted against mean dilation for Experiment 1 (D), Experiment 2 (E) and Experiment 3 (F).
Table 1.
Linear mixed effects models and results for Experiments 1–3 (significant results in bold).
Fig 4.
Experiment 2 trial sequence.
Fig 5.
Pupil dilation across the preparation period in Experiment 2.
Error bands depict standard error of the mean color vs shape difference scores.
Fig 6.
Examples of Experiment 3 stimuli.
Target-distractor color similarity was staircased to fix accuracy at 85% in easy search and 65% in difficult search.
Fig 7.
Pupil dilation across the preparation period in Experiment 3.
Error bands depict standard error of the mean color vs shape difference scores.