AUTHOR=Ewen Joshua B. , Pillai Ajay S. , McAuliffe Danielle , Lakshmanan Balaji M. , Ament Katarina , Hallett Mark , Crone Nathan E. , Mostofsky Stewart H. TITLE=Practicing Novel, Praxis-Like Movements: Physiological Effects of Repetition JOURNAL=Frontiers in Human Neuroscience VOLUME=10 YEAR=2016 URL=https://www.frontiersin.org/journals/human-neuroscience/articles/10.3389/fnhum.2016.00022 DOI=10.3389/fnhum.2016.00022 ISSN=1662-5161 ABSTRACT=

Our primary goal was to develop and validate a task that could provide evidence about how humans learn praxis gestures, such as those involving the use of tools. To that end, we created a video-based task in which subjects view a model performing novel, meaningless one-handed actions with kinematics similar to praxis gestures. Subjects then imitated the movements with their right hand. Trials were repeated six times to examine practice effects. EEG was recorded during the task. As a control, subjects watched videos of a model performing a well-established (over learned) tool-use gesture. These gestures were also imitated six times. Demonstrating convergent validity, EEG measures of task-related cortical activation were similar in topography and frequency between the novel gesture task and the overlearned, praxis gesture task. As in studies assessing motor skill learning with simpler tasks, cortical activation during novel gesture learning decreased as the same gestures were repeated. In the control condition, repetition of overlearned tool-use gestures were also associated with reductions in activation, though to a lesser degree. Given that even overlearned, praxis gestures show constriction of EEG activity with repetition, it is possible that that attentional effects drive some of the repetition effects seen in EEG measures of activation during novel gesture repetition.