On the form of the internal model for reaching

Exp Brain Res. 1995;104(3):467-79. doi: 10.1007/BF00231981.


We investigated, by using simulations, possible mechanisms responsible for the errors in the direction of arm movements exhibited by deafferented patients. Two aspects of altered feedforward control were evaluated: the inability to sense initial conditions and the degradation of an internal model. A simulation which assumed no compensation for variations in initial arm configuration failed to reproduce the characteristic pattern of errors. In contrast, a simulation that assumed random variability in the generation of joint torque resulted in a distribution of handpaths which resembled some aspects of the pattern of errors exhibited by deafferented patients.

Publication types

  • Clinical Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Arm / innervation
  • Arm / physiology
  • Elbow / physiology
  • Humans
  • Models, Neurological
  • Movement / physiology*
  • Neurons, Afferent / physiology
  • Shoulder / physiology