EEG AND NEOCORTICAL FUNCTION: BBS Call for Commentators

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(a)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(a)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(a)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 *** ------------------------------------------------------------------ (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 --------------------------------------------------------------------- (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. --------------------------------------------------------------------- (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/ -------------------------------------------------------------------- (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(a)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 --------------------------------------------------------------------- (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!).