Space-Time Accuracy of Rapid Movements

Abstract

The space-time accuracy of an elbow flexion movement task was examined in two experiments over a range of motion extents (1° through 100°) and short-duration movement times (100, 125, 150, and 400 ms). Nonlinear speed-accuracy functions emerged for both spatial and temporal error over all the movement conditions examined. The results showed that the timing error and spatial error had a high degree of complementarity as predicted by a space-time model of the speed-accuracy relation (Hancock & Newell, 1985). The findings confirm that the frame of reference for measuring movement error determines in part the error functions observed.

Key Words:

• impulse variability
• movement speed-accuracy
• timing