(A) Abbreviated task sequence; see Figure 1—figure supplement 1 for full task sequence. The interval between target onset and center lever lift defines the decision reaction time (RT). The yellow and blue glyphs are choice targets, and the gray ‘+’ shapes indicate the location of visual crowders designed to obscure the targets until they are viewed (fixated) directly. For clarity, in this panel crowders are shown in gray and at a reduced scale; on the actual task display, crowders were multicolored and the same size as the targets, as in panel C. (B) An example set of 12 choice targets, organized into 5 groups corresponding to the 5 levels of juice reward. (C) Close-up view of a single target array, consisting of a central yellow choice target surrounded by six non-task-relevant visual crowders. Two such arrays appear on the display (panel A), each located 7.5° from the display center. (D–F). Task performance. (D) Fraction of left choices as a function of the left minus right target value (in units of juice drops). (E) Reaction Time (RT) decreases as a function of difficulty, defined as the absolute difference between target values; (F) Number of fixations per trial decreases as a function of difficulty. Filled circles show the mean values and smooth lines show the logistic (D) or linear (E–F) regression fits derived from mixed effects models (Supplementary file 1, rows 1–3, respectively). Error bars are too small to be plotted. The data in blue are from Monkey C (N = 15,613), and in red, from Monkey K (N = 14,433).
© 2021, McGinty and Lupkin. Figure 1A-C are reproduced from Figure 1A-C of McGinty and Lupkin, 2021, bioRxiv, published under the CC-BY-NC 4.0 International license (https://creativecommons.org/licenses/by-nc/4.0/).