J.J. Wright, R.R. Kydd, D.T.J. Liley (1993) Eeg Models: Chaotic and Linear . Psycoloquy: 4(60) Eeg Chaos (1)
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Psycoloquy 4(60): Eeg Models: Chaotic and Linear

Target Article by Wright Kydd and Liley on EEG Chaos

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@ccu1.auckland.ac.nz jjw@brain.physics.swin.oz.au


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.


chaos, EEG simulation, electroencephalogram, linear dynamics, neocortex, network symmetry, neurodynamics, pyramidal cell, wave velocity.