| dc.description.abstract | Bimanual coordination and unimanual aiming are two of the most studied areas in motor learning and control research. However, these areas of study have been combined in only a few experiments. By manipulating the location and the size of targets in Lissajous displays, we combined bimanual coordination tasks with Fitts’ aiming tasks to form bimanual aiming in three experiments.
Experiments 1 and 2 were designed primarily to determine the degree to which the accuracy requirement influences the bimanual control processes when the Index of Difficulty (ID) was systematically increased between trials (Experiment 1) and within trials (Experiment 2) and to determine if the control strategies used to perform bimanual aiming are similar to those used in unimanual aiming. The results indicated that, as ID increased, the end-effectors’ motion gradually switched from cyclical to discrete motion for both unimanual and bimanual aiming tasks. However, the transition in control strategy occurred at a lower ID for the bimanual than the unimanual aiming task. In terms of bimanual coordination, increasing the accuracy requirement/ID reduced relative phase bias between the two limbs, whereas the stability of the coupling remained similar across IDs.
Two tasks (A, B) were designed in Experiment 3 to provide performers opportunities to choose between different manual control strategies. Task A was designed so that the participants could complete the task using either unimanual or bimanual control, whereas Task B was designed so that participants could complete the task using simple or less stable bimanual coordination patterns. The purpose was to determine which control strategy the participants would choose to complete the two tasks and determine the degree to which the accuracy requirement influences the control strategy chosen. The results indicated that for both Tasks A and B at the low ID condition (ID = 2) participants preferred to use a 90° bimanual coordination pattern that is continuous, but may be more difficult from the bimanual coordination standpoint. At the high ID condition (ID = 4), the participants consistently chose to switch between more stable unimanual left and right movements in Task A and to perform a discrete 90° bimanual coordination pattern in Task B. | en |
