Dr. Curt Boylls
Department of Defense
April 16, 1996

Title:  Conditioning speech recognition on sensorimotor principles

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To establish better paradigms for automated speech recognition may take
new science.  On the other hand, if we assume that speech operates within
the same neural framework that governs other sensorimotor processes, then
there is plenty of "old science" that we might yet profitably exploit.

In this talk, we will look at how the neuroscience community developed new
theory and methodology for discovering and describing the control of
complex sensorimotor tasks.  We'll also introduce some outrageous
analogies with the present situation in speech recognition.  Our story
starts about 25 years ago, when sensorimotor neuroscience was suffering
from its own version of the "independence assumption":  the notion that
the brain programs the actions of the body by playing a keyboard somehow
connected to thousands of independently controllable state variables
(e.g., muscle tensions and related kinematics) inherent in the
skeletomuscular system.  We will see how that concept was displaced by the
idea that, through the imposition of neurally-mediated constraints among
states, the effective dimensionality of the skeletomotor apparatus is
reduced to an exceptionally low order, one manageable within the resources
available to attention and short-term memory.  Part of this constraining
operation includes the segregation (conceptually and anatomically) of
processes that detail the events defining an action versus processes that
modulate those sequences (in, say, rate and intensity).  Each of these
elements typically operates within its own characteristic timescale; and
what we observe during skeletomotor activity is the superposition of all
their influences.

If facts from speech eventually confirm the tortured conjectures drawn
here from studies of locomotion and postural control, then corresponding
recognizer architectures are fairly obvious.  But the confirmatory step
may not be required if one merely wishes to benefit today's technology;
and we will conclude with some speculations toward that end.

Curt Boylls, a neurophysiologist, has been with the Department of Defense
for 11 years.

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Seminar Schedule