Experimental Brain Research

, Volume 80, Issue 2, pp 351–364

Parietal area 5 neuronal activity encodes movement kinematics, not movement dynamics

  • J. F. Kalaska
  • D. A. D. Cohen
  • M. Prud'homme
  • M. L. Hyde
Article

DOI: 10.1007/BF00228162

Cite this article as:
Kalaska, J.F., Cohen, D.A.D., Prud'homme, M. et al. Exp Brain Res (1990) 80: 351. doi:10.1007/BF00228162

Summary

A previous study reported that proximal-arm related area 5 neurons showed continuously-graded changes in activity during unloaded arm movements in different directions (Kalaska et al. 1983), which resembled the responses of primary motor cortex cells in several respects (Georgopoulos et al. 1982). We report here that loading the arm reveals an important difference between cell activity in the two areas. Loads were continuously applied to the arm in different directions. The loads produced large continuously-graded changes in muscle activity but did not alter the handpath or joint angle changes of the arm during the movements. The activity of most area 5 cells was only weakly affected by the loads, and the overall pattern of population activity was virtually unaltered under all load conditions. This indicates that area 5 activity encodes the invariant spatial parameters (kinematics) of the movements. In contrast, many motor cortex cells showed large changes in activity during loading, and so signal the changing forces, torques or muscle activity (movement dynamics; Kalaska et al. 1989).

Key words

Parietal cortex Reaching Kinematics Direction-Dynamics Loads Primate 

Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • J. F. Kalaska
    • 1
  • D. A. D. Cohen
    • 1
  • M. Prud'homme
    • 1
  • M. L. Hyde
    • 2
  1. 1.Centre de Recherche en Sciences Neurologiques, Départment de Physiologie, Faculté de MédecineUniversité de Montréal, MontréalQuébecCanada
  2. 2.Department of Veterinary and Comparative Anatomy, Pharmacology and PhysiologyCollege of Veterinary Medicine, Washington State UniversityPullmanUSA