Figure 1.
Thresholding procedure. a. An angle of discrimination is determined to be the closest angle two directions of motion may be when separated by 2000 ms and retain a just 100% level of performance. b. Two sets of three colors are determined for the experimental stimulus set. A set of three colors consists of a reference (the same for each subject) and one color on either side of it (along the axis) determined as the closest colors to the reference that retains a just 100% level of performance.