Covariation of attentional cost and stability provides further evidence for two routes to learning new coordination patterns.

This study investigated how learning a new bimanual coordination pattern affects the attentional resources allotted by the CNS to maintain it throughout the acquisition process. The repertoire of the existing stable coordination patterns was individually evaluated before and after practice in order to detect expected changes with learning. Bistable participants, who initially exhibited stable and accurate coordination patterns at 0 degrees and 180 degrees of relative phase, practiced a 90 degrees pattern, whereas multistable participants, who already mastered the 90 degrees pattern, practiced 135 degrees pattern instead. In a typical dual-task paradigm, all participants had to simultaneously perform a reaction time task that assessed the associated attentional cost. Beyond an overall increase in accuracy, the results revealed a significant decrease in the attentional cost for bistable participants, accompanying the stabilization of the 90 degrees pattern with learning, but not for multistable participants, as the 135 degrees pattern barely stabilized. Pattern stability and attentional cost co-evolve during learning and the process follows two different routes depending on the interplay between the task and the learner's coordination abilities before practice.

Memory dynamics: distance between the new task and existing behavioural patterns affects learning and interference in bimanual coordination in humans.

In order to study memory and learning dynamics, we examined the effects of the distance between a bimanual pattern to be learned, a relative phase of either 90 degrees, 135 degrees, or 158 degrees, and pre-existing patterns at 0 degrees and 180 degrees. Learning was assessed through a practice task, memory through a synchronization-continuation task, and interference through a prompting task recalling nearby patterns. Results were that (1) interference induced a smaller decrease in accuracy and in stability for the pattern closest to the pre-existing patterns; (2) the withdrawal of the stimulus in the continuation task led to consistent changes in accuracy; and (3) learning rate was faster when the to-be-learned pattern was either far from or close to extant patterns. The findings are discussed in terms of flexibility and robustness of underlying coordination dynamics, and of neural-field dynamic models.