Neurobehavioral quantification of the transition to explicit awareness in skilled motor learning: Implications for rehabilitation

Abstract

We often take for granted the ability to learn and execute sequential movements in a smooth, automatic manner on a continual daily basis. Unfortunately, many patient populations exhibit deficits in motor learning, impairing the ability to develop such sequential motor skills. Understanding the individual neural progression associated with sequential learning in healthy individuals may provide valuable insights of motor learning as well as identify factors that can impede learning. Recent studies have indicated potential therapeutic benefits to the incidental development of explicit awareness during a motor learning task, but have not addressed the potential confound of variability in individual learning rates. We identified an individualized indicator of incidentally developed explicit awareness to more precisely examine the neurobehavioral changes associated with sequential motor learning to a level of explicit awareness. EEG results revealed the presence of a facilitative frontoparietal network for subjects demonstrating awareness, that was not present for those failing to develop awareness. Additional neurobehavioral correlations provided evidence for the impact of working memory on the ability to acquire initial explicit awareness, and the impact of learning strategy on the ability to successfully transfer the newly learned skill to a novel, more complex motor task. Finally, a multimodal approach examined eye-tracking, kinematics and neural activity changes for prosthesis users and intact control subjects when learning a sequential motor task. Prosthesis users demonstrated neurobehavioral patterns reflective of enhanced visual reliance for motor control, impacting motor learning progression. It was additionally noted that prosthesis users developing awareness appeared to engage in behaviors which introduced additional sensorimotor information relevant to motor learning. The individualized approach in the presented work provide insight into rehabilitative interventions with which to assist individuals experiencing motor learning deficits.