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Consciousness, cognition, and the hierarchy of context:
extending the global neuronal workspace model
Rodrick Wallace
The New York State Psychiatric Institute
*
February 6, 2004
Abstract
We adapt an information theory analysis of interacting cog-
nitive biological and social modules to the problem of the
global neuronal workspace, the new standard neuroscience
paradigm for consciousness. Tunable punctuation emerges in
a natural way, suggesting the possibility of fitting appropriate
phase transition power law, and, away from transition, gen-
eralized Onsager relation expressions, to observational data
on conscious reaction. The development can be extended
in a straightforward manner to include psychosocial stress,
culture, or other cognitive modules which constitute a struc-
tured, embedding, hierarchy of contextual constraints acting
at a slower rate than neuronal function itself. This produces
a ‘biopsychosococultural’ model of individual consciousness
that, while otherwise quite close to the standard treatment,
meets compelling philosophical and other ob jections to brain-
only descriptions.
Key words: asymptotic limit theorems, cognition, con-
sciousness, Dretske, information theory, Onsager relations,
phase transition, renormalization.
Introduction
A recent special issue of Cognition (79(1-2), 2001)) explores
contemporary work on consciousness in humans, presenting
various aspects of the new ‘standard model’ synthesized over
the last decade or so (esp. Dehaene and Naccache, 2001).
Sergeant and Dehaene (2004) describe that work, and some
of the implicit controversy, as follows:
“[A growing body of empirical study shows] large
all-or-none changes in neural activity when a stimu-
lus fails to be [consciously] reported as compared to
when it is reported... [A] qualitative difference be-
tween unconscious and conscious processing is gen-
erally expected by theories that view recurrent in-
teractions between distant brain areas as a nec-
essary condition for conscious perception... One
of these theories has proposed that consciousness
is associated with the interconnection of multiple
* Address correspondence to Rodrick Wallace, PISCS Inc., 549 W 123
St., Suite 16F, New York, NY, 10027. Telephone (212) 865-4766, email
[email protected]. Affiliation is for identification only.
areas processing a stimulus by a [dynamic] ‘neu-
ronal workspace’ within which recurrent connec-
tions allow long-distance communication and auto-
amplification of the activation. Neuronal network
simulations... suggest the existence of a fluctuating
dynamic threshold. If the primary activation evoked
by a stimulus exceeds this threshold, reverberation
takes place and stimulus information gains access,
through the workspace, to a broad range of [other
brain] areas allowing, among other processes, ver-
bal report, voluntary manipulation, voluntary action
and long-term memorization. Below this thresh-
old, however, stimulus information remains unavail-
able to these processes. Thus the global neuronal
workspace theory predicts an all-or-nothing tran-
sition between conscious and unconscious percep-
tion... More generally, many non-linear dynamical
systems with self-amplification are characterized by
the presence of discontinuous transitions in internal
state...”
The review by Baars (2002) provides a somewhat different
perspective on recent rapid progress in this direction, exam-
ining his own pioneering studies (Baars, 1983, 1988), along
with the work of Edleman (1989), Damasio (1989), Freeman
(1991), Llinas et al. (1998), Edelman and Tononi (2000), and
so on.
Baars and Franklin (2003) describe the overall model as
having the following features:
(1) The brain can be viewed as a collection of distributed
specialized networks (processors).
(2) Consciousness is associated with a global workspace in
the brain - a fleeting memory capacity whose focal contents
are widely distributed (‘broadcast’) to many unconscious spe-
cialized networks.
(3) Conversely, a global workspace can also serve to inte-
grate many competing and cooperating input networks.
(4) Some unconscious networks, called contexts, shape con-
scious contents, for example unconscious parietal maps mod-
ulate visual feature cells that underlie the perception of color
in the ventral stream.
(5) Such contexts work together jointly to constrain con-
scious events.
(6) Motives and emotions can be viewed as goal contexts.