Global Workspace Theory (GWT) of Bernard J. Baars
I plan to digress from my typical format for this section because I believe
reviewing the "Theory Roots" first will make Bernard J. Baars' ideas more readily
acceptable.
Theory Roots:
Beginning with Sigmund Freud's idea of the subconscious, a belief has
grown that the workings of the conscious mind run much deeper than the images
and melodies which play inside our heads. Something outside of the "conscious"
realm seems to be molding our thoughts and actions. G. A. Miller put it succinctly:
"Consciousness gives no clue as to where the answer comes from; the
processes that produce it are unconscious. It is (the) result
of thinking, not the process of thinking, that appears spontaneously
in consciousness."
(Miller, 1962, p. 56).
Essentially, we know that we speak in sentences, but we are not aware of how
the nouns, verbs, and modifiers are assembled before they spew from our mouths.
We can imagine a purple elephant with yellow polka dots, but why it appears standing
or sitting, left side or right side facing us (or other positioning), we do not know. We
can even make our imaginary elephant fall over. But why the tumbling goes
one way or the other, we cannot say. It just happens. (By the way, is your elephant
an Indian elephant or an African elephant? Imagine the ears. The ears should
roughly resemble the continent to which the elephant is indiginous. African elephants
have larger, "Africa" shaped ears, and Indian elephants have smaller, diamond or
"India" shaped ears. On the other hand, if the ears look rather human, then you
should go to the zoo more often!)
Yet, we know that something has assembled the words coming out of
our mouths. We know that something has positioned our imaginary elephant.
Something decided on large or small polka dots, and then tumbled the elephant left
or right, forward or backwards, or whichever way it fell. It is this magical array of
displays which I now draw your attention and which Baars attempts to explain. It
is all a part of consciousness, but then again ... not quite. It is on the edge of
consciousness, and it taunts us. Bernard J. Baars has created a complex and integrated
explanation for both consciousness and its subconscious or unconscious underpinnings.
Using a theater analogy with an audience, stagehands/artists, and actors, Baars has crafted his
compelling Global Workspace Theory (GWT).
Basic Ideas:
Bernard J. Baars postulates consciousness as a workspace which acts like a
theater stage. The actors are images and sounds (and perhaps other sense feelings)
created and manipulated by "specialized processors" which, to follow the analogy, are
the artists and stagehands who create "input to the stage".
The analogy is reminiscent of animations or cartoons where artists create drawings
and images which are flashed upon a screen. With animation, an artist or team of artists may
handle the backgrounds. Some just draw figures. Others color the drawings. Simultaneously,
each animated character will have its own team of artists. Again, one produces the outline of the
figure while another colors it. Meanwhile, other members of the team produce and coordinate
the voice "talent" of the animated character. Thus, the life given the images is purely simulated
and created by a team of skilled and highly specialized workers.
Carrying this analogy back to the mind, these skilled and highly specialized workers
("artists") are Baars' "specialized processors". One "team" may produce line drawings and shades
of grey (correlating to input from the "rods" of the eye). Another team may color these images
(correlating to input from the "cones" of the eye). Other teams probably handle motion or
positioning as well as sound and volume. (To get a sense of the immense number of facets
which may be handled by specialized/contextual processors of consciousness, I encourage you
to read "DISNEY ANIMATION The Illusion of Life", and then go watch an animated movie.
While you are watching, just remember that all you see and hear was first designed, drawn,
colored, and directed inside of someone's imagination - a consciousness mind.)
Meanwhile, Baars describes "receiving processors" as an audience to receive and
evaluate the "output images" from the stage (or screen) of the theater. This "audience reaction"
then influences the actions of the artists and stagehands in producing the animation on the screen
in the "theater of consciousness". If the audience takes particular interest in one of the screen
characters, that character will be moved to the "center stage" of consciousness by the "artists".
Others images of less appeal may shift to the background or drop from the scene entirely. And,
once again, just as with a true animated feature, the audience may be completely unaware of the
artists behind the scenes creating the images flashed upon the screen of consciousness. The
audience has the illusion that all is magically happening on the screen instantaneously with no
other actions or operations to create it.
Most appealing from an evolutionary point of view is Baars belief that the
specialized processors compete with each other to gain access to the workspace - the
theatrical stage. They may even form coalitions (called "contexts" by Baars) in order
to improve their ability to affect the stage. These coalitions are also affected by
feedback from the receiving processors ("the audience"). Thus, Baars enables a
rich potential for explaining all mental activities by enabling alternate groupings
(contexts), competition, and feedback loops (the audience's reaction).
Baars strengthens his theory by integrating his ideas with factual knowledge
from neurobiology:
"... competition through the global workspace, which can be viewed as
lowering activation levels of global messages, and cooperation, which
raises those activation levels ... 'Lowering and raising activation levels'
is of course analogous to excitation and inhibition in neurons."
(Baars, 1988, p. 359-360).
Baars has also tied his work to an integrated cerebral system he denotes as the
Extended Reticular-Thalamic Activating System (ERTAS). In particular, he suggests
the nucleus reticularis thalami (nRT) as a possible seat for the global workspace
given its competitive inputs.
Importance:
Without an explanation of consciousness, including its underpinnings, any
theory of the mind would be hollow, for it is consciousness which we seem most
involved with from moment to moment. Any notion of "why we do what we do" or
"why we say what we say" cannot escape the notion of consciousness. It is
central to our interest in understanding the mind.
Baars' Global Workspace Theory is a comprehensive and integrated attempt
to explain consciousness. To ignore Baars' work would leave a gaping hole requiring
some explanation. Any theory of the mind must explain consciousness. Baars has
pioneered a way to do it.
Further Reading:
A Cognitive Theory of Consciousness.
Bernard J. Baars - NEW YORK: Cambridge University Press, 1988. ISBN 0-521-42743-6
In the Theater of Consciousness.
Bernard J. Baars - NEW YORK: Oxford University Press, 1997. ISBN 0-19-510265-7
DISNEY ANIMATION The Illusion of Life.
Frank Thomas and Ollie Johnston - NEW YORK: Abbeville Press, 1984. ISBN 0-89659-498-X
