Dimensional complexity of neuromagnetic activity reduced during finger movement of greater difficulty.

Full Abstract

OBJECTIVE:
We investigated the variation in dimensionality (D2) of neuromagnetic activity over the primary sensorimotor cortex (SM1) in healthy adults performing motor tasks of different difficulty.

METHODS:
Magnetoencephalography (MEG) was used to record neuromagnetic activity during self-paced, brisk unimanual finger extension at a rate of 1 and 2 Hz using the index finger of the dominant and non-dominant hands in 16 healthy subjects. Motor task difficulty was rated by the relative difference in time measurement between 1 and 2 Hz finger movements of both hands. The relative difference in dimensionality of SM1 activity was calculated by subtracting the D2 value in 2 Hz movement from that in 1 Hz one within subjects.

RESULTS:
Simple regression analyses show a significantly negative relationship between the relative dimensional complexity and the relative motor task difficulty in the contralateral SM1 for the left- (p<0.05), but not the right- (p=0.447) hand movement.

CONCLUSIONS:
The present data suggest that a motor task of greater difficulty may engender a reduction of simultaneously active quasi-independent neuronal generators in the contralateral SM1 underpinned by stronger neuronal connectivity of a relatively low dimensionality.

SIGNIFICANCE:
The decrease in dimensional complexity of MEG activity associated with a motor task of greater difficulty gives new insights to motor control strategy.

Learn Faster Today Improve your study skills

Author information

Author/s: Wu, Yu-Zu (YZ); Yang, Ting-Hui (TH); Lin, Yung-Yang (YY); Chen, Shyan-Shiou (SS); Liao, Kwong-Kum (KK); Chen, Li-Fen (LF); Yeh, Tzu-Chen (TC); Wu, Yu-Te (YT); Ho, Low-Tone (LT); Hsieh, Jen-Chuen (JC);

Affiliation: Institute of Neuroscience, School of Life Science, National Yang-Ming University, Taipei, Taiwan.

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology (Clin Neurophysiol), published in Netherlands. (Language: eng)

Reference: 2006-Nov; vol 117 (issue 11) : pp 2473-81

Dates: Created 2006/10/18; Completed 2007/01/10; Revised 2008/09/10;

PMID: 16949339, status: MEDLINE (last retrieval date: 12/26/2008)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article (including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.

MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Adult
Algorithms
Data Interpretation, Statistical
Female
Fingers - innervation; physiology
Functional Laterality - physiology
Humans

Humans
Magnetoencephalography
Male
Motor Cortex - physiopathology
Motor Skills - physiology
Movement - physiology
Somatosensory Cortex - physiopathology

These are the highest related articles currently in the database:

See 100+ related articles.