Wright, Kydd & Liley's (1993) article attempting to harmonize locally chaotic EEG dynamics with globally linear dynamics does not address Mitra and Skinner's (1992) evidence for nonstationary temporal signals in limit set dimension. That phenomenon requires a more sophisticated model of global EEG dynamics for its explanation.
2. Wright et al.'s suggestion that chaos is present in local dynamics appears supportable. In addition to Mitra & Skinner's work, my own simulation work (Erwin, 1994, following Freeman and Yao, 1990) shows microscopic chaos and suggests at least two roles for it within the olfactory system: stochastic resonance and modulation of parallel signal channels to avoid illusionary correlations. Despite those positive results, my modeling is far from the biology and should only be regarded as suggestive. In particular, I have not addressed training, a key deficiency, given the role of expectation in my simulation and in Mitra & Skinner's data.
3. A macroscopic model of EEG should address some issues that arise specifically at the transition from locally chaotic dynamics to the macroscopic scale. My simulation results here are again similar to Mitra and Skinner's data: the system appears to enter a low dimensional state in response to the presentation of a known pattern. An unanswered question here is whether the pyriform cortex is responding to the direct measurement of synchronized efferent data streams or to an indirect identification of the partially coherent state attained by the olfactory bulb. The latter will reduce the efferent data rate in vivo. This will have some influence on the global EEG model.
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Mitra, M. & Skinner, J.E. (1992) Low-Dimensional Chaos Maps Learning in a Model Neuropil (Olfactory Bulb). Integrative Physiological and Behavioral Science, Volume 27, Number 4, 304-322.
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Wright, J.J., Kydd, R.R. & Liley, D.T.J. (1993) EEG Models: Chaotic and Linear. PSYCOLOQUY 4(60) eeg-chaos.1.wright.