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View Full Version : Motor Control (Feldman): BBS Call for Commentators



sharnad19
08-05-1994, 10:25 AM
Below is the abstract of a forthcoming target article by:
A.G. Feldman & M.F. Levin
on:
POSITIONAL FRAMES OF REFERENCE IN MOTOR CONTROL

This article has been accepted for publication in Behavioral and Brain
Sciences (BBS), an international, interdisciplinary journal providing
Open Peer Commentary on important and controversial current research in
the biobehavioral and cognitive sciences.

Commentators must be current BBS Associates or nominated by a current
BBS Associate. To be considered as a commentator for this article, to
suggest other appropriate commentators, or for information about how to
become a BBS Associate, please send email to:

harnad@clarity.princeton.edu or harnad@pucc.bitnet or write to:
BBS, 20 Nassau Street, #240, Princeton NJ 08542 [tel: 609-921-7771]

To help us put together a balanced list of commentators, please give
some indication of the aspects of the topic on which you would bring
your areas of expertise to bear if you were selected as a commentator.
An electronic draft of the full text is available for inspection by
anonymous ftp according to the instructions that follow after the abstract.
__________________________________________________ __________________

POSITIONAL FRAMES OF REFERENCE IN MOTOR CONTROL: ORIGIN AND USE

Anatol G. Feldman (1,2,4) & Mindy F. Levin (2,3,4)
Institute of Biomedical Engineering, University of Montreal (1)
Research Centre, Rehabilitation Institute of Montreal, H3S 2J4 (2)
School of Rehabilitation, University of Montreal (3)
Centre for Research in Neurological Sciences, University of Montreal (4)
EMAIL:Feldman@ere.umontreal.ca

KEYWORDS: motor control, frames of reference, motoneurons, control
variables, proprioception, kinaesthesis, equilibrium points,
multi-muscle systems, pointing, synergy, redundancy problem.

ABSTRACT: A hypothesis about sensorimotor integration (the lambda
model) is described and applied to movement control and
kinesthesia. The nervous system organizes positional frames of
reference for the sensorimotor apparatus and produces active
movements by shifting frames in terms of spatial coordinates.
Kinematic and electromyographic patterns are not programmed but
emerge from the dynamic interaction of the system's components,
including external forces, within the designated frame of
reference. Motoneuronal threshold properties and proprioceptive
inputs to motoneurons may be important components in the
physiological mechanism which produces positional frames of
reference. The hypothesis that intentional movements are produced
by shifting the frame of reference is extended to multi-muscle and
multi-degrees of freedom systems by providing a solution for the
redundancy problem the allows the control of a joint alone or in
combination with other joints to produce any desired limb
configuration and movement trajectory. For each motor behavior, the
nervous system uses a strategy which minimizes the number of
changeable control variables and keep sthe parameters of these
changes invariant. This is illustrated by examples of simulated
kinematic and electromyographic signals from single- and
multi-joint arm movements produced by patterns of control
variables. Empirical support is provided and additional tests are
suggested. The model is contrasted with others based on the ideas
of programming of motoneuronal activity, muscle forces, stiffness
or movement kinematics.

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you feel you would bring to bear on what aspect of the article.
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http://192.190.21.10/wic/psych.02.html

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