Reinforcement Learning is Impaired in the Sub-acute Post-stroke Period.

Background: In humans, most spontaneous recovery from motor impairment after stroke occurs in the first 3 months. Studies in animal models show higher responsiveness to training over a similar time-period. Both phenomena are often attributed to a milieu of heightened plasticity, which may share some mechanistic overlap with plasticity associated with normal motor learning.

Divided Attention Has Limited Effects on Speech Sensorimotor Control.

Purpose: When vowel formants are externally perturbed, speakers change their production to oppose that perturbation both during the ongoing production (compensation) and in future productions (adaptation). To date, attempts to explain the large variability across individuals in these responses have focused on trait-based characteristics such as auditory acuity, but evidence from other motor domains suggests that attention may modulate the motor response to sensory perturbations. Here, we test the extent to which divided attention impacts sensorimotor control for supralaryngeal articulation.

The Kinematics of 3D Arm Movements in Sub-Acute Stroke: Impaired Inter-Joint Coordination is Attributable to Both Weakness and Flexor Synergy Intrusion.

Background: It has long been of interest to characterize the components of the motor abnormality in the arm after stroke. One approach has been to decompose the hemiparesis phenotype into negative signs, such as weakness, and positive signs, such as intrusion of synergies. We sought to identify the contributions of weakness and flexor synergy to motor deficits in sub-acute stroke.

Fundamental processes in sensorimotor learning: Reasoning, refinement, and retrieval.

Motor learning is often viewed as a unitary process that operates outside of conscious awareness. This perspective has led to the development of sophisticated models designed to elucidate the mechanisms of implicit sensorimotor learning. In this review, we argue for a broader perspective, emphasizing the contribution of explicit strategies to sensorimotor learning tasks.