EEG Models: Chaotic and Linear: PSYCOLOQUY Call for Commentary

Note: This is a PSYCOLOQUY Call for Commentators, *not* a BBS Call: You are invited to submit a formal commentary on the target article whose abstract appears below. It has just been published in the refereed electronic journal PSYCOLOQUY. Instructions for retrieving the full article and for preparing a PSYCOLOQUY commentary appear after the abstract. All commentaries are refereed. TARGET ARTICLE AUTHOR'S RATIONALE FOR SOLICITING COMMENTARY The target article attempts to reconcile attractor neural network (ANN) theory with certain current models for the generation of the EEG as a step toward integrating ANN theory with gross observations of brain function. Emphasis is placed on symmetry of cortical connections at a macroscopic level as compared to symmetry at a microscopic level. We hope to elicit commentary on (1) the methodology of the experiments and simulations on which the work is based, (2) any contradictory experimental findings, (3) quantitative methods in anatomy required for further development, (4) other critiques of ANN applicability to global brain function. psycoloquy.93.4.60.EEG-chaos.1.wright Thursday 23 December 1993 ISSN 1055-0143 (53 parags, 12 equations, 3 figs, 62 refs, 1092 lines) PSYCOLOQUY is sponsored by the American Psychological Association (APA) Copyright 1993 JJ Wright, RR Kydd & DTJ Liley EEG MODELS: CHAOTIC AND LINEAR J.J. Wright, R.R. Kydd, D.T.J. Liley Department of Psychiatry and Behavioural Science, School of Medicine, University of Auckland, Auckland, New Zealand jwright(a)ccu1.auckland.ac.nz jjw(a)brain.physics.swin.oz.au ABSTRACT: Two complementary EEG models are considered. The first (Freeman 1991) predicts 40+ Hz oscillation and chaotic local dynamics. The second (Wright 1990) predicts propagating EEG waves exhibiting linear superposition, nondispersive transmission, and near-equilibrium dynamics, on the millimetric scale. Anatomical considerations indicate that these models must apply, respectively, to cortical neurons which are very asymmetrically coupled and to symmetric average couplings. Aspects of both are reconciled in a simulation which explains wave velocities, EEG harmonics, the 1/f spectrum of desynchronised EEG, and frequency-wavenumber spectra. Local dynamics can be compared to the attractor model of Amit and Tsodyks (1990) applied in conditions of highly asymmetric coupling. Nonspecific cortical afferents may confer an adiabatic energy landscape to the large-scale dynamics of cortex. KEYWORDS: chaos, EEG simulation, electroencephalogram, linear dynamics, neocortex, network symmetry, neurodynamics, pyramidal cell, wave velocity. ------------------------------------------------------------------- INSTRUCTIONS FOR PSYCOLOQUY COMMENTATORS Accepted PSYCOLOQUY target articles have been judged by 5-8 referees to be appropriate for Open Peer Commentary, the special service provided by PSYCOLOQUY to investigators in psychology, neuroscience, behavioral biology, cognitive sciences and philosophy who wish to solicit multiple responses from an international group of fellow specialists within and across these disciplines to a particularly significant and controversial piece of work. If you feel that you can contribute substantive criticism, interpretation, elaboration or pertinent complementary or supplementary material on a PSYCOLOQUY target article, you are invited to submit a formal electronic commentary. Please note that although commentaries are solicited and most will appear, acceptance cannot, of course, be guaranteed. 1. Before preparing your commentary, please read carefully the Instructions for Authors and Commentators and examine recent numbers of PSYCOLOQUY. 2. Commentaries should be limited to 200 lines (1800 words, references included). PSYCOLOQUY reserves the right to edit commentaries for relevance and style. In the interest of speed, commentators will only be sent the edited draft for review when there have been major editorial changes. Where judged necessary by the Editor, commentaries will be formally refereed. 3. Please provide a title for your commentary. As many commentators will address the same general topic, your title should be a distinctive one that reflects the gist of your specific contribution and is suitable for the kind of keyword indexing used in modern bibliographic retrieval systems. Each commentary should have a brief (~50-60 word) abstract 4. All paragraphs should be numbered consecutively. Line length should not exceed 72 characters. The commentary should begin with the title, your name and full institutional address (including zip code) and email address. References must be prepared in accordance with the examples given in the Instructions. Please read the sections of the Instruction for Authors concerning style, preparation and editing. PSYCOLOQUY is a refereed electronic journal (ISSN 1055-0143) sponsored on an experimental basis by the American Psychological Association and currently estimated to reach a readership of 36,000. PSYCOLOQUY publishes brief reports of new ideas and findings on which the author wishes to solicit rapid peer feedback, international and interdisciplinary ("Scholarly Skywriting"), in all areas of psychology and its related fields (biobehavioral, cognitive, neural, social, etc.) All contributions are refereed by members of PSYCOLOQUY's Editorial Board. Target article length should normally not exceed 500 lines [c. 4500 words]. Commentaries and responses should not exceed 200 lines [c. 1800 words]. All target articles, commentaries and responses must have (1) a short abstract (up to 100 words for target articles, shorter for commentaries and responses), (2) an indexable title, (3) the authors' full name(s) and institutional address(es). In addition, for target articles only: (4) 6-8 indexable keywords, (5) a separate statement of the authors' rationale for soliciting commentary (e.g., why would commentary be useful and of interest to the field? what kind of commentary do you expect to elicit?) and (6) a list of potential commentators (with their email addresses). All paragraphs should be numbered in articles, commentaries and responses (see format of already published articles in the PSYCOLOQUY archive; line length should be < 80 characters, no hyphenation). It is strongly recommended that all figures be designed so as to be screen-readable ascii. If this is not possible, the provisional solution is the less desirable hybrid one of submitting them as postscript files (or in some other universally available format) to be printed out locally by readers to supplement the screen-readable text of the article. PSYCOLOQUY also publishes multiple reviews of books in any of the above fields; these should normally be the same length as commentaries, but longer reviews will be considered as well. Book authors should submit a 500-line self-contained Precis of their book, in the format of a target article; if accepted, this will be published in PSYCOLOQUY together with a formal Call for Reviews (of the book, not the Precis). The author's publisher must agree in advance to furnish review copies to the reviewers selected. Authors of accepted manuscripts assign to PSYCOLOQUY the right to publish and distribute their text electronically and to archive and make it permanently retrievable electronically, but they retain the copyright, and after it has appeared in PSYCOLOQUY authors may republish their text in any way they wish -- electronic or print -- as long as they clearly acknowledge PSYCOLOQUY as its original locus of publication. However, except in very special cases, agreed upon in advance, contributions that have already been published or are being considered for publication elsewhere are not eligible to be considered for publication in PSYCOLOQUY, Please submit all material to psyc(a)pucc.bitnet or psyc(a)pucc.princeton.edu Anonymous ftp archive is DIRECTORY pub/harnad/Psycoloquy HOST princeton.edu ------------------------------------------------------------- To retrieve the file by ftp from a Unix/Internet site, type either: ftp princeton.edu or ftp 128.112.128.1 When you are asked for your login, type: anonymous Enter password as per instructions (make sure to include the specified @), and then change directories with: cd /pub/harnad/Psycoloquy/1993.volume.4 To show the available files, type: ls Next, retrieve the file you want with (for example): get psyc.93.4.60.EEG-chaos.1.wright [or you can abbreviate with: mget *wright When you have the file(s) you want, type: quit In case of doubt or difficulty, consult your system manager. A more elaborate version of these instructions for the U.K. is available on request (thanks to Brian Josephson)> These files can also be retrieved using gopher, archie, veronica, etc. ---------- Where the above procedures are not available (e.g. from Bitnet or other networks), there are two fileservers: ftpmail(a)decwrl.dec.com and bitftp(a)pucc.bitnet that will do the transfer for you. To one or the other of them, send the following one line message: help for instructions (which will be similar to the above, but will be in the form of a series of lines in an email message that ftpmail or bitftp will then execute for you).