The Accuracy of Non-Visual Aiming

Abstract
A visual feedback theory of movement control developed earlier predicted that the accuracy of movements performed in darkness would be unaffected by movement speed, but be linearly related to distance. We found that for variable errors this is partly true; a linear relationship to distance was demonstrated, but an optimum speed was found. Constant errors showed interesting trends, showing the usual range effect but also being affected by movement time. Finally, a small irreducible component in these errors was found, which was considered to be caused by physiological tremor. These results are easily encompassed in our feedback theory, but would be difficult for an information theory based model of movement control.