Matching and Minimizing Movement Time in Speed-Accuracy Tasks.

The goal of present experiment was to test whether different speed-accuracy paradigms outcomes (time minimization and time matching) were due to different temporal and spatial task constraints. Fifteen participants twice performed 100 trials of time minimization and time matching tasks with the yoked temporal and spatial requirements (criterion time and target width). The results showed that performing an aiming movement under the same spatial and temporal constraints resulted in similar outcomes with distributional properties (skewness and kurtosis) being slightly affected by practice effects. There was a trade-off in the information entropy for space and time (temporal information entropy decreased as spatial information entropy increased) with practice. Nevertheless, the joint space-time entropy of outcome did not change across tasks and conditions-revealing a common level of space-time entropy between these two categories of aiming tasks. These findings support the hypothesis that under the same spatial and temporal constraints the movement speed-accuracy function shares the same properties independent of task category.