Handedness and the excitability of cortical inhibitory circuits

Reid, Campbell S.; Serrien, Deborah J.

Abstract

Inhibitory processes play a significant role in the control of goal-directed actions. To increase insights into these mechanisms as a function of handedness, we measured the transient inhibition of volitional motor activity induced by single pulse transcranial magnetic stimulation during bimanual isometric contractions with symmetrical and asymmetrical force demands. Here, we assess the cortical silent period (cSP), which associates with intrahemispheric inhibition, and the ipsilateral silent period (iSP), which provides an estimation of interhemispheric inhibition. The data showed that inhibitory processes support the functional regulation of bimanual motor output. Furthermore, right-handers demonstrated asymmetries in intra- and interhemispheric inhibition due to asymmetrical force requirements and hand dominance, whereas left-handers did not show marked differences. In particular, right-handers demonstrated increased inhibitory processing that favoured control of the dominant (left) hemisphere whereas both motor cortices exhibited equal capabilities in left-handers. These observations were specific to the bimanual nature of the task. The present results underline distinct organisational mechanisms of coordinated behaviour in right- and left-handers.

Citation

Reid, C. S., & Serrien, D. J. (in press). Handedness and the excitability of cortical inhibitory circuits. Behavioural Brain Research, 230(1), https://doi.org/10.1016/j.bbr.2012.02.008

• Journal Article Type: Article
• Acceptance Date: Feb 2, 2012
• Online Publication Date: Feb 10, 2012
• Deposit Date: Jun 8, 2012
• Publicly Available Date: Jun 8, 2012
• Journal: Behavioural Brain Research
• Print ISSN: 0166-4328
• Electronic ISSN: 1872-7549
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 230
• Issue: 1
• DOI: https://doi.org/10.1016/j.bbr.2012.02.008
• Public URL: https://nottingham-repository.worktribe.com/output/709429
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0166432812001064
• Additional Information: NOTICE: this is the author’s version of a work that was accepted for publication in Behavioural Brain Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Behavioural Brain Research, 230, 1 (2012) doi:10.1016/j.bbr.2012.02.008