Abstract
While most research in motor control has supported a highly online control account of human limb movement, recent research suggests that there are priming effects between movements, when the movements are: a) performed in close succession and b) are similar in nature. In the present study, the individual components of the index of difficulty were perturbed during a discrete reciprocal manual aiming task. Participants performed sequences of 20 aiming movements with the index finger to targets presented to the left and right of the midline. Target perturbations occurred between the 8th and the 12th movement, manipulating target size in the first experiment and the distance between the two targets in the second. The trials of interest were the trials that immediately followed the target perturbation, as we wanted to see how individuals would react to the change in the difficulty of the task. The results of the experiment revealed that for the target size perturbation, two trials were required for movement time to coincide with the new index of difficulty. While for the distance perturbation, movement times always coincided with the given distance between the two targets. These findings suggest that information gathered from these two components may lead to different movement control strategies used by the participant.Acknowledgments: Natural Sciences and Engineering Research Council of Canada (Binsted & Cheng)