EEG AND NEOCORTICAL FUNCTION: BBS Call for Commentators
Stevan Harnad
harnad at coglit.ecs.soton.ac.uk
Fri Apr 9 13:37:32 EDT 1999
Below is the abstract of a forthcoming BBS target article:
NEOCORTICAL DYNAMIC FUNCTION AND EEG by Paul L. Nunez
This article has been accepted for publication in Behavioral and Brain
Sciences (BBS), an international, interdisciplinary journal providing
Open Peer Commentary on important and controversial current research in
the biobehavioral and cognitive sciences.
Commentators must be BBS Associates or nominated by a BBS Associate. To
be considered as a commentator for this article, to suggest other
appropriate commentators, or for information about how to become a BBS
Associate, please send EMAIL by May 14th to:
bbs at cogsci.soton.ac.uk
or write to [PLEASE NOTE SLIGHTLY CHANGED ADDRESS]:
Behavioral and Brain Sciences
ECS: New Zepler Building
University of Southampton
Highfield, Southampton
SO17 1BJ UNITED KINGDOM
http://www.princeton.edu/~harnad/bbs/
http://www.cogsci.soton.ac.uk/bbs/
ftp://ftp.princeton.edu/pub/harnad/BBS/
ftp://ftp.cogsci.soton.ac.uk/pub/bbs/
gopher://gopher.princeton.edu:70/11/.libraries/.pujournals
If you are not a BBS Associate, please send your CV and the name of a
BBS Associate (there are currently over 10,000 worldwide) who is
familiar with your work. All past BBS authors, referees and
commentators are eligible to become BBS Associates.
To help us put together a balanced list of commentators, please give
some indication of the aspects of the topic on which you would bring
your areas of expertise to bear if you were selected as a commentator.
An electronic draft of the full text is available for inspection
with a WWW browser, anonymous ftp or gopher according to the
instructions that follow after the abstract.
_____________________________________________________________
TOWARD A QUANTITATIVE DESCRIPTION OF LARGE SCALE
NEOCORTICAL DYNAMIC FUNCTION AND EEG.
Paul L. Nunez
Permanent Address:
Brain Physics Group,
Dept. of Biomedical Engineering,
Tulane University,
New Orleans,
Louisiana 70118
pnunez at mailhost.tcs.tulane.edu
Temporary Address (6/98 - 6/00):
Brain Sciences Institute,
Swinburne University of Technology,
400 Burwood Road,
Melbourne,
Victoria 3122,
Australia
pnunez at mind.scan.swin.edu.au
ABSTRACT: A conceptual framework for large-scale neocortical dynamic
behavior is proposed. It is sufficiently general to embrace brain
theories applied to different experimental designs, spatial scales
and brain states. This framework, based on the work of many
scientists, is constructed from anatomical, physiological and EEG
data. Neocortical dynamics and correlated behavioral/cognitive brain
states are viewed in the context of partly distinct, but interacting
local (regionally specific) processes and globally coherent
dynamics. Local and regional processes (eg, neural networks) are
enabled by functional segregation; global processes are facilitated
by functional integration. Global processes can also facilitate
synchronous activity in remote cell groups (top down) which function
simultaneously at several different spatial scales. At the same
time, local processes may help drive (bottom up) macroscopic global
dynamics observed with EEG (or MEG).
A specific, physiologically based local/global dynamic theory is
outlined in the context of this general conceptual framework. It is
consistent with a body of EEG data and fits naturally within the
proposed conceptual framework. The theory is incomplete since its
physiological control parameters are known only approximately. Thus,
brain state-dependent contributions of local versus global dynamics
cannot be predicted. It is also neutral on properties of neural
networks, assumed to be embedded within macroscopic fields.
Nevertheless, the purely global part of the theory makes
qualitative, and in a few cases, semi-quantitative predictions of
the outcomes of several disparate EEG studies in which global
contributions to the dynamics appear substantial. Experimental data
are used to obtain a variety of measures of traveling and standing
wave phenomena, predicted by the pure global theory. The more
general local/global theory is also proposed as a "meta-theory," a
suggestion of what large-scale quantitative theories of neocortical
dynamics may be like when more accurate treatment of local and
non-linear effects is achieved.
In the proposed local/global theory, the dynamics of excitatory and
inhibitory synaptic action fields are described. EEG and MEG are
believed to provide large-scale estimates of modulation of these
synaptic fields about background levels. Brain state is determined
by neuromodulatory control parameters. Some states are dominated by
local cell groups, in which EEG frequencies are due to local
feedback gains and rise and decay times of post-synaptic potentials.
Local frequencies vary with brain location. Other states are
strongly global, with multiple, closely spaced EEG frequencies, but
identical at each cortical location. Coherence at these frequencies
is high over large distances. The global mode frequencies are due to
a combination of delays in cortico-cortical axons and neocortical
boundary conditions. Many states involve dynamic interactions
between local networks and the global system, in which case observed
EEG frequencies may involve "matching" of local resonant frequencies
with one or more of the global frequencies.
KEYWORDS: EEG, neocortical dynamics, standing waves, functional
integration, spatial scale, binding problem, synchronization,
coherence, cell assemblies, limit cycles, pacemakers
____________________________________________________________
To help you decide whether you would be an appropriate commentator for
this article, an electronic draft is retrievable from the World Wide
Web or by anonymous ftp from the US or UK BBS Archive.
Ftp instructions follow below. Please do not prepare a commentary on
this draft. Just let us know, after having inspected it, what relevant
expertise you feel you would bring to bear on what aspect of the
article.
The URLs you can use to get to the BBS Archive:
http://www.princeton.edu/~harnad/bbs/
http://www.cogsci.soton.ac.uk/bbs/Archive/bbs.nunez.html
ftp://ftp.princeton.edu/pub/harnad/BBS/bbs.nunez
ftp://ftp.cogsci.soton.ac.uk/pub/bbs/Archive/bbs.nunez
*** FIVE IMPORTANT ANNOUNCEMENTS ***
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(1) There have been some very important developments in the
area of Web archiving of scientific papers very recently.
Please see:
Science:
http://www.cogsci.soton.ac.uk/~harnad/science.html
Nature:
http://www.cogsci.soton.ac.uk/~harnad/nature.html
American Scientist:
http://www.cogsci.soton.ac.uk/~harnad/amlet.html
Chronicle of Higher Education:
http://www.chronicle.com/free/v45/i04/04a02901.htm
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(2) All authors in the biobehavioral and cognitive sciences are
strongly encouraged to archive all their papers (on their
Home-Servers as well as) on CogPrints:
http://cogprints.soton.ac.uk/
It is extremely simple to do so and will make all of our papers
available to all of us everywhere at no cost to anyone.
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(3) BBS has a new policy of accepting submissions electronically.
Authors can specify whether they would like their submissions
archived publicly during refereeing in the BBS under-refereeing
Archive, or in a referees-only, non-public archive.
Upon acceptance, preprints of final drafts are moved to the
public BBS Archive:
ftp://ftp.princeton.edu/pub/harnad/BBS/.WWW/index.html
http://www.cogsci.soton.ac.uk/bbs/Archive/
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(4) BBS has expanded its annual page quota and is now appearing
bimonthly, so the service of Open Peer Commentary can now be be
offered to more target articles. The BBS refereeing procedure is
also going to be considerably faster with the new electronic
submission and processing procedures. Authors are invited to submit
papers to:
Email: bbs at cogsci.soton.ac.uk
Web: http://cogprints.soton.ac.uk
http://bbs.cogsci.soton.ac.uk/
INSTRUCTIONS FOR AUTHORS:
http://www.princeton.edu/~harnad/bbs/instructions.for.authors.html
http://www.cogsci.soton.ac.uk/bbs/instructions.for.authors.html
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(5) Call for Book Nominations for BBS Multiple Book Review
In the past, Behavioral and Brain Sciences (BBS) journal had only
been able to do 1-2 BBS multiple book treatments per year, because
of our limited annual page quota. BBS's new expanded page quota
will make it possible for us to increase the number of books we
treat per year, so this is an excellent time for BBS Associates and
biobehavioral/cognitive scientists in general to nominate books you
would like to see accorded BBS multiple book review.
(Authors may self-nominate, but books can only be selected on the
basis of multiple nominations.) It would be very helpful if you
indicated in what way a BBS Multiple Book Review of the book(s) you
nominate would be useful to the field (and of course a rich list of
potential reviewers would be the best evidence of its potential
impact!).
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