QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, May 13, 2009, 29(19):6353-6357; doi:10.1523/JNEUROSCI.0631-09.2009

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Post, M. Articles by Zijdewind, I. Search for Related Content PubMed PubMed Citation Articles by Post, M. Articles by Zijdewind, I.

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
Inadvertent Contralateral Activity during a Sustained Unilateral Contraction Reflects the Direction of Target Movement

Marijn Post, Rob Bakels, and Inge Zijdewind

Department of Neuroscience, Medical Physiology, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands

Correspondence should be addressed to Inge Zijdewind, Department of Neuroscience, Medical Physiology, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands. Email: i.zijdewind{at}med.umcg.nl

Strong unilateral contractions are accompanied by excitatory effects to the ipsilateral cortex. This activity can even result in overt contractions of muscles in the contralateral limb. We used this inadvertent, associated activity to study whether the cortical presentation of movements is organized in a directional-related or a muscle-related reference frame. We assessed the contralateral activation for the left index finger during a sustained maximal abduction of the right index finger. In the first experiment, both hands were held vertically in a symmetrical orientation, and in the second experiment the hands were in an asymmetrical orientation (left hand, palm downward; right hand, vertical). In both experiments, the direction of the contralateral associated contraction was upward, i.e., in the symmetrical hand orientation the contralateral force increased mainly in abduction direction, whereas in the asymmetrical hand orientation the contralateral force increased in the extension direction. Thus, the contralateral contractions reflected the direction of the target movement rather than simply the activity of the muscles activated on the target side. These observations provide strong evidence that motor commands are organized in an extrinsic, direction-related reference frame, as opposed to an internal muscle-related reference frame.

---

Received Feb. 6, 2009; revised March 31, 2009; accepted April 20, 2009.

Correspondence should be addressed to Inge Zijdewind, Department of Neuroscience, Medical Physiology, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands. Email: i.zijdewind{at}med.umcg.nl

This article has been cited by other articles:

				F. Giovannelli, A. Borgheresi, F. Balestrieri, G. Zaccara, M. P. Viggiano, M. Cincotta, and U. Ziemann Modulation of interhemispheric inhibition by volitional motor activity: an ipsilateral silent period study J. Physiol., November 15, 2009; 587(22): 5393 - 5410. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help