Experimental Brain Research

, Volume 155, Issue 1, pp 19–23

Transcranial magnetic stimulation reveals asymmetrical efficacy of intracortical circuits in primary motor cortex

Authors

    • School of PsychologyThe University of Western Australia
  • Deb Faulkner
    • School of PsychologyThe University of Western Australia
    • Centre for Neuromuscular and Neurological DisordersThe University of Western Australia
  • Michelle Byrnes
    • Centre for Neuromuscular and Neurological DisordersThe University of Western Australia
  • Frank Mastaglia
    • Centre for Neuromuscular and Neurological DisordersThe University of Western Australia
  • Gary Thickbroom
    • Centre for Neuromuscular and Neurological DisordersThe University of Western Australia
Research Article

DOI: 10.1007/s00221-003-1696-x

Cite this article as:
Hammond, G., Faulkner, D., Byrnes, M. et al. Exp Brain Res (2004) 155: 19. doi:10.1007/s00221-003-1696-x

Abstract

The efficacy of inhibitory and excitatory intracortical circuits acting on the representation of an intrinsic hand muscle in the primary motor cortex of both hemispheres was measured with paired transcranial magnetic stimuli in right-handed subjects. Both intracortical inhibition (measured with an interstimulus interval of 3 ms) and intracortical facilitation (measured with an interstimulus interval of 16 ms) developed more rapidly with increasing conditioning stimulus intensity in the dominant than the non-dominant hand. We conclude that the intracortical circuits in the primary motor cortex are more potent in the dominant than the non-dominant hemisphere, and hypothesize that this difference is a factor in the asymmetrical dexterity associated with hand preference.

Keywords

HandednessMotor cortexTMSIntracortical inhibitionIntracortical facilitation

Copyright information

© Springer-Verlag 2004