title: Electrical signs of cortical involvement in the automatic control of grip force.
abstract: Evoked potentials were recorded in 10 subjects to assess cortical involvement in automatic control of grip force during restraint of a manipulandum held between finger and thumb. Brisk pulling loads elicited an increase in first dorsal interosseous EMG after 60.6 +/- 2.4 ms. Preceding this response were several time-locked scalp potentials, the most significant being a widespread negativity that appeared first over the frontal cortex and peaked 19.5 +/- 1.8 ms before the EMG peak, and a positivity that followed the EMG by 24.3 +/- 5.4 ms. The slope of the negativity and the amplitude of the positivity were greater than during passive conditions, suggesting that these potentials reflect cortical processes associated with automatic regulation.
authors.affiliation: Department of Physiology, University of Umeå, Sweden.
authors.forename: V G
authors.initials: VG
authors.lastname: Macefield
authors.forename: R S
authors.initials: RS
authors.lastname: Johansson
mesh_terms: D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology*; D004576:Electromyography; D004594:Electrophysiology; D005073:Evoked Potentials, Somatosensory; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D011930:Reaction Time