Figure 10. Methods of Experiment 3.

A) Top view of the force fields for a movement from position n to position n+1, which in this case is closer and to the right. Blue arrows show the assisting forces, which could be 1N or 2N and red arrows show the resisting forces, which could also be 1N or 2N. B) Top view of the nine target positions relative to the subject. C) Example sequence of stimuli for the first four trials in an assisting force field. First a green target was shown at the origin; the subject moved to that position and pressed the button on the phantom; then a new green target appeared with a force of 1N pulling the hand in the direction of the target; on reaching the target the subject pressed button again, and a new target and force appeared, and so on. The blue arrows indicate the constant force in the direction from the previous (open grey circle) to the current target position.