Figure 1.
(Left) Schematic of one experimental trial. The circular aperture remains stationary while the dots inside it move in a single direction. The subject fixates at the central square from a viewing distance of 60 cm and decides if the motion directions of the two stimuli are the same or different. Feedback is provided after each trial. (Right) Experimental design. Session 1: the subjects’ baseline performance is measured in the two test directions, t1 and t2. Session 2: they practice in the test direction t1 and their performance is measured. Sessions 3–6: they then practice extensively in the two directions, p1 and p2. Session 7: they practice in the test direction t2, and the performance is measured. The assignment of the two test directions, t1 and t2, was counter-balanced across subjects.