Preserved motor learning after stroke is related to the degree of proprioceptive deficit

Eric D Vidoni,Lara A Boyd

doi:10.1186/1744-9081-5-36

Abstract

BackgroundMost motor learning theories posit that proprioceptive sensation serves an important role in acquiring and performing movement patterns. However, we recently demonstrated that experimental disruption of proprioception peripherally altered motor performance but not motor learning in humans. Little work has considered humans with central nervous system damage. The purpose of the present study was to specifically consider the relationship between proprioception and motor learning at the level of the central nervous system in humans.MethodsIndividuals with chronic (> 6mo) stroke and similarly aged healthy participants performed a continuous tracking task with an embedded repeating segment over two days and returned on a third day for retention testing. A limb-position matching task was used to quantify proprioception.ResultsIndividuals with chronic stroke demonstrated the ability to learn to track a repeating segment; however, the magnitude of behavioral change associated with repeated segment-specific learning was directly related to the integrity of central proprioceptive processing as indexed by our limb-position matching task.ConclusionThese results support the importance of central sensory processing for motor learning. The confirmation of central sensory processing dependent motor learning in humans is discussed in the context of our prior report of preserved motor learning when sensation is disrupted peripherally.

Highlights

Most motor learning theories posit that proprioceptive sensation serves an important role in acquiring and performing movement patterns
Behavioral and Brain Functions 2009, 5:36 http://www.behavioralandbrainfunctions.com/content/5/1/36 parietal activity interferes with adaptation [7] little other direct evidence links somatosensory processing to motor learning in humans
Despite overall difference in tracking accuracy, both groups demonstrated repeated segment-specific learning over the course of the experiment

Summary

Introduction

Most motor learning theories posit that proprioceptive sensation serves an important role in acquiring and performing movement patterns. We recently demonstrated that experimental disruption of proprioception peripherally altered motor performance but not motor learning in humans. The purpose of the present study was to consider the relationship between proprioception and motor learning at the level of the central nervous system in humans. It is commonly held that sensory feedback plays an important role in motor skill learning [1,2,3]. Physiologic evidence from animal lesion models suggests that sensory cortex is necessary for learning new skills, including movement sequences. Animals with experimentally induced lesions to S1 fail to acquire new motor skills with the contralesional hand. Though activation of the sensory cortex has been linked to excitation of the human motor cortex [6], and disruption of (page number not for citation purposes)

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