Notes and comments the role of action feedback in the acquisition of simple motor responses

The use of visual action feedback (AIF) in learning a simple motor response can sometimes be as effective as the more conventional terminal feedback (TIF) but sometimes leads to gross overshooting errors when AIF is removed. Both the amplitude of movement and the gain of the AIF have strong and systematic effects on the error in attempted reproductions. Percent overestimation increases linearly with fog. gain and decreases linearly with log. amplitude. This may be due to an intersensory effect in which visual and kinesthetic feedback sum to form a unitary impression of the movement on which subsequent attempts at reproduction are based.