[extropy-chat] Neat paper on neuronal model of aspects of consciousness

Neil Halelamien neuronexmachina at gmail.com
Wed Apr 13 09:17:32 UTC 2005

Yesterday the journal PLoS Biology released an article, where
researchers describe a neuronal model they've devised of certain
aspects of consciousness.

Synopsis (for the layman): "Assessing Consciousness: Of Vigilance and


Research paper: "Ongoing Spontaneous Activity Controls Access to
Consciousness: A Neuronal Model for Inattentional Blindness"


In general, Stanislas Dehaene (one of the paper's authors) has some
very cool publications on neuroscience, consciousness, cognition, and
so forth. You can find them here:


Below is a quote from the aforementioned synopsis:

Have you ever walked smack into a parking meter or tripped over
something on the sidewalk? Embarrassing as such incidents may be,
they're the product of normal brain function. The brain is
continuously bombarded with sensory information about the environment
but perceives just a fraction of these inputs. The rest--pertinent
details or not--is filtered out. It's thought that consciousness
emerges from the activity of multiple spontaneous neural processors
that run in parallel and connect to a higher order cognitive network
that mediates the conscious perception. But this higher order network
has limited processing capacity. That means if you're distracted, your
brain can't accommodate additional sensory information, like "there's
a parking meter in front of you, look out!"

To understand how spontaneous brain processing interacts with higher
order cognition, Stanislas Dehaene and Jean-Pierre Changeux modeled
the dynamic properties of brain activity with computer simulations.
Their simulations show that while spontaneous brain activity sometimes
facilitates processing, more often it competes with external stimuli
for access to consciousness. Intriguingly, the results of the computer
simulations very closely match physiological and psychophysical
experimental data and thus shed new light on how intrinsic brain
activity modulates conscious perception. ...

With higher vigilance states, weaker external stimuli are able to
ignite the global workspace. But paying attention to one thing narrows
your perceptive capacity. Once ignited by one stimulus, the network
cannot consciously process any others. Dehaene and Changeux propose
that spontaneous activity--which operates within an "anatomically
distinct set of workplace neurons"--offers an organism a measure of
autonomy relative to the external world. While this decoupling of
internal thought and external stimuli does have its
disadvantages--like that pesky parking meter--it also provides the
opportunity for introspection and creativity, which the authors argue
is likely to "play a crucial role in the spontaneous generation of
novel, flexible behavior."

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