These are excerpts and elaborations from my book "The Nature of Consciousness"
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The Cartesian Theater The Dutch psycholinguist
Bernard Baars believes that conscious experience is distributed widely
throughout the nervous system and ultimately originates from a Darwinian
process of selection applied to experience. Consciousness creates access
to a large amount of knowledge, or, more precisely, to a large number of
unconscious sources of knowledge. When I am conscious of typing words into a
computer, I am not aware of the keyboard, of the fact that computers are
machines, of the movement of my fingers and of many other things, although each
of those is essential to perform this task. All that knowledge exists, but is
unconscious. Consciousness is very limited in how many things it can do (be
conscious of) and for how long (it can keep them in short-term memory). But the
brain as a whole does not have those limitations. Consciousness is a
"gateway" to the vast knowledge stored in the brain. In order to explain how this
works, Baars employs the metaphor of a "theater". Baars views the nervous system as a
set of independent intelligent agents that broadcast messages to each other
through a common workspace (just as if they were writing on a blackboard
visible to every other agent). That
workspace, the stage of the theater, is consciousness. Any conscious experience
emerges from cooperation and competition between the many processing units of
the brain working in parallel. The mind originates from the work of many
independent, specialized "processors", i.e. skills that have become
highly practiced, automatic and unconscious. There are two sets of
unconscious processes: the ones backstage, that, like the playwright and the
director, determine what is played on the stage, and the ones in the audience,
that capture what is being played. Whenever consciousness of something is
created, the "audience" retrieves knowledge about that something.
Consciousness is the gateway to the unconscious processes of the brain just
like the stage is the gateway to the audience. Through consciousness, the
backstage processes broadcast a message to all the spectator processes. Baars emphasizes the striking
differences between conscious and unconscious processes: unconscious processes
are much more effective (e.g., we parse sentences unconsciously all the time,
but cannot consciously describe how we parse them), they operate in parallel
(whereas we can only have one conscious process at the time), they appear to
have almost unlimited capacity (conscious processes have very limited
capacity). The conscious
"stage" interacts with several unconscious "experts" that
create goals and plans and compete for playing them on the stage. These experts
are "modules" (eyesight, fear, hunger, etc) that compete for access
to the "global workspace". A form of "natural selection"
decides which module (or modules) is predominant at any time. Consciousness is the stage,
and the modules are the actors. Actors are competing for the spotlight. Back to the beginning of the chapter "Consciousness: the Factory of Illusions" | Back to the index of all chapters |
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