Figure 1.

Experimental design and learning. A–D, Hand orientations and associated force fields, as force vectors experienced by the hand (zero velocity represented by the black circle) for the four groups of subjects. Note that the three vector fields are displayed separately, for clarity, but act over the same workspace. Similarly, the actual end point location of the hand for the three hand orientations is matched across the three conditions, but is separated here for clarity. Start location, targets, and cursor were displayed as a circle, showing position with a line indicating the orientation (inset).