Fig. 2.

Hand trajectory (dashed gray line) from an example run of the continuous tracking task (“distance” block). A single trial is highlighted in blue, with arrowheads indicating movement direction. The choice target (red circle) appeared at the moment the subject was at the position indicated by the red dot. After a short “switch reaction time” (SRT), the subject abandoned the tracked target, switched direction, and entered the choice target at the point indicated by the green square. Gray circles and open squares indicate analogous events in other trials within the same continuous run.