Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/28225
Appears in Collections:Psychology Journal Articles
Peer Review Status: Refereed
Title: Cortical control of muscle relaxation: A lateralized readiness potential (LRP) investigation
Author(s): Pope, Paul
Holton, Andrew
Hassan, Sameh
Kourtis, Dimitrios
Praamstra, Peter
Contact Email: dimitrios.kourtis@stir.ac.uk
Keywords: EEG
lateralized readiness potential
movement-related potentials
muscle relaxation
inhibition
Issue Date: 31-May-2007
Date Deposited: 7-Nov-2018
Citation: Pope P, Holton A, Hassan S, Kourtis D & Praamstra P (2007) Cortical control of muscle relaxation: A lateralized readiness potential (LRP) investigation. Clinical Neurophysiology, 118 (5), pp. 1044-1052. https://doi.org/10.1016/j.clinph.2007.02.002
Abstract: Objective: We used the lateralized readiness potential (LRP) to investigate cortical mechanisms underlying the termination of muscle contraction. Active suppression and withdrawal of activation have been proposed as underlying mechanisms in isotonic and isometric relaxation.  Methods: Experiment 1 investigated isotonic wrist extension/release from extension. Experiment 2 investigated isometric activation/relaxation of a pinch grip. Tasks were performed with left and right hands and cued auditorily at variable intervals. EEG was recorded from 128 electrodes and processed to derive the LRP timelocked to the onset and offset of muscle contraction.  Results: LRPs for isotonic activation and relaxation were of identical amplitude at electrodes overlying the motor cortex, but differed at frontal locations due to higher amplitude re-afferent activity during activation. The isometric LRP was significantly smaller during relaxation than during activation, without differences in scalp distribution. Conclusion: The LRP findings confirm differences between isotonic and isometric relaxation, which may be partly explained by the need to suppress a stretch reflex in the former condition. The presence of an LRP associated with isometric relaxation reveals active preparation in the motor cortex, indicating that muscle relaxation in the isometric task cannot be explained solely by withdrawal of activation. Significance: High-density LRP recordings isolate different cortical mechanisms underlying the termination of muscle contraction. © 2007 International Federation of Clinical Neurophysiology.
DOI Link: 10.1016/j.clinph.2007.02.002
Rights: The publisher does not allow this work to be made publicly available in this Repository. Please use the Request a Copy feature at the foot of the Repository record to request a copy directly from the author. You can only request a copy if you wish to use this work for your own research or private study.
Licence URL(s): http://www.rioxx.net/licenses/under-embargo-all-rights-reserved

Files in This Item:
File Description SizeFormat 
2007_Pope_etal_ClinNeurophy.pdfFulltext - Published Version418.59 kBAdobe PDFUnder Permanent Embargo    Request a copy

Note: If any of the files in this item are currently embargoed, you can request a copy directly from the author by clicking the padlock icon above. However, this facility is dependent on the depositor still being contactable at their original email address.



This item is protected by original copyright



Items in the Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

The metadata of the records in the Repository are available under the CC0 public domain dedication: No Rights Reserved https://creativecommons.org/publicdomain/zero/1.0/

If you believe that any material held in STORRE infringes copyright, please contact library@stir.ac.uk providing details and we will remove the Work from public display in STORRE and investigate your claim.