These pages have been designed as a source of discussion regarding the chaotic
aspects of brain dynamics. Most of the information presented has
been gleaned from papers discussing and interpreting electroencephalogram
readings from both human and rodent brains. These experiments are
significant for a variety of reasons; the main ones we have considered
are those with implications in the field of brain state modeling. This is
the most direct application of the EEG findings. These new models for
brain activity suggest a need for the revamping of conceptions of
perceptual processes and overall brain functioning. The new models may or
may not replace existing models such as the ART neural model, or the connectionist
models of neural nets; certainly the older neural-net models will have to
be modified and/or fleshed out to meet with the explanatory power of these
new models. The nature of the findings are these:
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(a) there is global spacio-temporal structure to brain states measurable
by the EEG;
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(b) these
states when studied in the olfactory bulb show structural transformation
with respect to conditioned and novel stimuli;
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(c) stable state structure
(quiescent EEG) within the olfactory bulb corresponds to a chaotic
attractor with dimension between 4 and 7;
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(d) dynamical structure of the EEG
readings has a period unique to each conditioned stimulus; and
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(e) novel
stimuli produce an EEG reading corresponding to higher-dimension chaos with
respect to the `background' chaotic attractors.
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Chris King, who has written extensively on the subject of brain
chaos and its implications, says of olfactory response to stimuli,
On inhalation a transition occurs from low level chaos. . . to a
trajectory which in the case of a familiar odor will settle into one of
several periodic orbits, but in the case of a new odor will avoid existing
periodic attractors hunting chaotically until a new periodic attractor is
established over time, forming a both a new familiarized response and a new
symbol. [1]
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This quotation gives an introduction to one of the main focuses of this
website: the role of chaos. We will also be discussing some significant
features of chaotic dynamics as a way of understanding global brain
function, as well as some discussion of chaotic dynamics on the local
scale.
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