Abstract
Prior to training, only two coordinated rhythmic movements are stable: 0° and 180°. Other coordinations (e.g. 90°) must be learned. This pattern emerges from a task dynamic in which relative phase is perceived as the relative direction of motion, modified by the relative speed (Bingham, 2004). People can learn how to move at 90° but this entails learning to use a different information variable (relative position; Wilson & Bingham, 2008). Learning a novel coordination requires feedback, however, and typically this feedback is presented in the form of a transformed display such as a Lissajous plot. This display removes relative motion of any kind as a source of information about relative phase and simply requires people to track a template; as a result, people can move at any required coordination with brief practice. Wilson et al (2010) developed a second form of feedback, coordination feedback, which doesn’t alter the information available for relative phase and preserves relative position as an option. The current study directly compared the two feedback methods. 12 participants learned to move bimanually at 90° using either Lissajous (N=6) or coordination (N=6) feedback. We tested coordination stability with both displays in baseline, post training and retention sessions, with baseline and post training separated by 5 training sessions. Both feedback methods improved performance at 90°, but there was no transfer of this learning between the feedback displays. The two feedback methods create different task dynamics that are informationally distinct from one another, and participants learned to use different information to support their actions. This result confirms that a) the two feedback methods provide different perceptual information and that b) perceptual learning underpins the improvements in movement stability, even in the bimanual version of the task. Information is a key part of a perception-action analysis of this task (Bingham, 2004).
Meeting abstract presented at VSS 2012