Optimizing the control of high ID movements: rethinking the obvious.

An experiment was designed to determine the degree to which instruction and visual display influence participants' performance and control characteristics when executing difficult reciprocal aiming movements. Participants were randomly assigned to one of the three acquisition conditions (Fitts, Impulse and Sine). Participants in the Fitts condition were asked to flex/extend their limb/lever in the horizontal plane at the elbow joint (wrist stabilized) in an attempt to move back and forth between two targets as quickly and accurately as possible. In the Impulse condition, participants moved between two target lines paced by a metronome, and in the Sine condition, participants were asked to track a sine wave pattern. The timing for the Impulse and Sine conditions was set to result in total times (movement time + dwell time) similar to that observed in our previous experiments using the same Fitts conditions. The respective display and current position of the limb were projected on the screen in front of the participant. Following nine acquisition trials (15 s each) under their assigned condition, Test 1 was conducted under the same conditions as the participant experienced during the acquisition, and then, Test 2 was conducted for all participants under the Fitts' conditions. The results for Test 1 indicated that total time and movement time for the three groups did not differ. However, dwell time was significantly lower, a larger proportion of movement time was spent in the acceleration portion of the movement, and peak velocity was significantly lower for the participants in the Sine condition than for participants in the Fitts condition. On Test 2, where Fitts conditions were imposed, the Sine group outperformed the Fitts condition on all variables except hits and endpoint variability where the Fitts and Sine groups performed similarly.

RCT Entities:   Population Interventions Outcomes