Document Detail


Anticipatory postural adjustment before bimanual unloading reactions: the role of the motor cortex in motor learning.
MedLine Citation:
PMID:  17763984     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The role of the motor cortex in forming a learned coordination (stabilization of the forearm on unloading) was studied in humans. Subjects maintained a 1-kg weight with the right (postural) forearm, the weight being attached via an electromagnet. Unloading of the postural arm was initiated by the subjects by lifting a similar load with the left arm. In control experiments, lifting of the load did not lead to unloading of the postural arm. Changes in motor cortex excitability were studied by transcranial magnetic stimulation applied to the representation area of the right biceps muscle in the motor cortex at the beginning and end of the experiments. Repeated unloading tests showed progressive decreases in the amplitude of the movement of the unloaded forearm, which were accompanied by increases in the anticipatory inhibition of the electromyogram of the biceps muscle of the unloaded arm (learning). Muscle responses to transcranial magnetic stimulation during the learning process showed no significant changes. Analysis of normalized muscle responses to transcranial magnetic stimulation (response/baseline) showed that these increased at the end of training and reached a significantly higher level than seen at the beginning of training. These results lead to the conclusion that the motor cortex plays a fundamental role in inhibiting synergies and coordinations which would interfere with the formation of the new coordination during motor learning.
Authors:
O V Kazennikov; I A Solopova; V L Talis; M E Ioffe
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Neuroscience and behavioral physiology     Volume:  37     ISSN:  0097-0549     ISO Abbreviation:  Neurosci. Behav. Physiol.     Publication Date:  2007 Sep 
Date Detail:
Created Date:  2007-09-03     Completed Date:  2007-12-06     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0330471     Medline TA:  Neurosci Behav Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  651-7     Citation Subset:  IM    
Affiliation:
Institute of Information Transmission Problems, Russian Academy of Sciences, Russia.
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MeSH Terms
Descriptor/Qualifier:
Adult
Analysis of Variance
Electric Stimulation / methods
Electromyography / methods
Female
Functional Laterality*
Humans
Learning / physiology*
Male
Middle Aged
Motor Cortex / physiology*
Motor Skills / physiology*
Muscle, Skeletal / innervation,  physiology
Posture / physiology*
Reaction Time / physiology,  radiation effects
Transcranial Magnetic Stimulation
Weight-Bearing / physiology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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