[From Rick Marken (991027.2200)]
I just ran across the following abstract of a paper in the
latest _Psycgological Review_ (October 1999, Vol. 106,
No. 4, 714�747).
···
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The Referential Dynamics of Cognition and Action
Jeff Pressing
University of Melbourne
Referential behavior theory (RBT), a general dynamical approach to
psychological and related systems that operate through a control
or referencing process, is introduced. A review of existing evidence
shows that this approach can apply to a variety of human and
animal systems and tasks, whether the framing language is that of
homeostasis, error correction, coupled biological oscillators,
motor control, adaptive change, cognitive goal-setting, evaluation
and refinement, or neural network learning. Thus, RBT provides
a path for reconciliation of dynamical and information-processing
accounts of action and cognition. RBT generates a class of
mathematical equations, one of which, the discrete control equation
(DCE), forms the basis for more detailed investigation. The primary
focus here is on the application of the DCE to the temporal
structure of regular human movement. Given certain conditions,
the equation produces various standard (and new, more general)
forms of the circle map class that governs relative phase in
motor coordination and, hence, generates well-documented nonlinear
�dynamical� motor phenomena such as behavioral attractors, phase
transitions, critical slowing, and so on. Under certain other
conditions, the DCE produces the linear stochastic timing models
often associated with motor program traditions, accommodating
hierarchical effects, open- and closed-loop conditions, and unilimb
and multilimb movement. A number of new predictions are identified
from the approach, and a review of experimental evidence gives
support for the claim that the current formulation is an integrated
generalization and improvement of several aspects of existing
motor program and dynamic approaches.
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Could the DCE be equivalent to the closed loop input-output
equation (4) in my "Blind Man..." paper?
(4) r = s*/k.f - (k.e/k.f) d
Could Mr. Pressing have discovered that "...nonlinear 'dynamical'
motor phenomena such as behavioral attractors, phase transitions,
critical slowing, and so on" could be observable side effects of
control of input? If so, Mr. Pressing has spearheaded the PCT
revolution in psychology all on his own; more proof that good
things come in Australian packages.
Best
Rick
--
Richard S. Marken Phone or Fax: 310 474-0313
Life Learning Associates e-mail: rmarken@earthlink.net
http://home.earthlink.net/~rmarken/