Fig. 1.

The 1-line and 2-line test conditions. (A) Trial sequence of the 1-line test conditions. The 50° and 53° lines were run in separate blocks. (B) Trial sequence of the 2-line test condition. The 50° and 53° lines were presented in each trial in counterbalanced, pseudorandomized order. For each condition, the marker dots appeared randomly at either horizontal or vertical initial positions, and subjects rotated them and clicked to report orientation(s). See Methods for details and the actual stimulus parameters.