Figure 1.

Experiment methods. A: experimental apparatus and setup. B: schematic overview of the 2 × 2 design in experiment 1. The target (blue dot) was blanked from the screen before participants initiated their reach. Feedback was only presented at the endpoint, in the form of a cursor (white dot) or cloud of dots. The dotted line is included to graphically highlight the two clamp angles (not drawn to scale), pointing from the start position to the centroid of the feedback. C: trial sequence for the visual discrimination task. The centroid of the comparison stimulus (cursor or cloud) was positioned clockwise or counterclockwise relative to the target location at an angle (θ) equal to 1 of 5 rotation angles (see text). In the example shown, the comparison stimulus is a cursor (white circle) shifted 5° clockwise from the referent stimulus (position depicted in blue outline but not visible on the screen). The participants reported whether they perceived the centroid to be clockwise or counterclockwise relative to the remembered target location.