Fig. 1.

The planets and moons tracking (PMT) paradigm. a One target dot (blue/dark) and one distractor dot (yellow/light) were spaced evenly around an invisible circle. Color and shading is for illustration purposes only, as all dots in the experimental displays were white. Groups of dots (dotted boxes) were spaced evenly around a larger invisible circle centered on the fixation cross. Dots moved on two axes of rotation shown here with arrows. Each group moved around the central fixation cross at the same rate. Simultaneously, dots making up each group also rotated around their group centers. This design allowed target-distractor proximity and speed to be examined independently. b The PMT display for two distractors in each group (Experiment 2)