The EEG is Not a Simple Noise: Strange Attractors in Intracranial Structures

  • J. Röschke
  • E. Başar


Since Berger’s (1929) first description of the electrical activity of the brain, several approaches have been undertaken in order to correlate the activity at neuronal levels with the origin of the electroencephalogram (EEG). Creutzfeldt (1974) pointed out that the spontaneous electrical activity of the CNS and sensory evoked potentials are highly correlated to intracellularly measured postsynaptic potentials (EPSPs and IPSPs). Ramos et al. (1976) postulated that it is impossible to specify any general causal or predictable relationship between the waveform of an evoked potential and the firing pattern of a neuron. Some authors take the view that the spontaneous EEG activity is an expression of the incessant, irregular background neural firing. Do we have the right to consider the spontaneous activity of the brain as a background noise in the sense of ideal communication theory? Or rather, is the EEG a most important fluctuation, which controls the sensory evoked and event-related potentials? We have written elsewhere that the spontaneous activity plays an active role in the signals transmitted through various structure and recorded at various sites in the brain and that the EEG should not be considered as a noisy signal. Especially, we have assumed that regular patterns of the EEG reflect coherent states of the brain during which cognitive and sensory inputs are processed (Başar 1980, 1983a, b).


Phase Space Fractal Dimension Chaotic System Spontaneous Activity Chaotic Attractor 
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  1. Babloyantz A, Nicolis C, Salazar M (1985) Evidence of chaotic dynamics of brain activity during the sleep cycle. Phys Lett [A] 111: 152–156CrossRefGoogle Scholar
  2. Başar E (1980) EEG-brain dynamics. Relation between EEG and brain evoked potentials. Elsevier/ North-Holland, AmsterdamGoogle Scholar
  3. Başar E (1983a) Toward a physical approach to integrative physiology. I. Brain dynamics and physical causality. Am J Physiol 245(4): R510–R533PubMedGoogle Scholar
  4. Başar E (1983b) Synergetics of neuronal populations. In: Başar E, Flohr H, Haken H, Mandell AJ (eds) Synergetics of the brain. Springer, Berlin Heidelberg New YorkGoogle Scholar
  5. Berger H (1929) Über das Elektroencephalogramm des Menschen. Arch Psychiatr Nervenkr 87:527–570CrossRefGoogle Scholar
  6. Creutzfeldt OD (1974) The neuronal generation of the EEG. In: Renard A (ed) Handbook of elec-troencephalography and clinical neurophysiology. Elsevier, AmsterdamGoogle Scholar
  7. Farmer JD (1982) Dimension, fractal, measures, and chaotic dynamics. In: Haken H (ed) Evolution of order and chaos. Springer, Berlin Heidelberg New YorkGoogle Scholar
  8. Fraser AM (1985) Using mutual information to estimate metric entropy in dimensions and entropies in chaotic systems. In: Mayer-Kress G (ed) Dimensions and entropies in chaotic systems. Springer, Berlin Heidelberg New York TokyoGoogle Scholar
  9. Grassberger P, Procaccia I (1983) Measuring the strangeness of strange attractors. Physica [D] 9:183–208Google Scholar
  10. Holzfuss J (1985) An approach to error-estimation in the application of dimension algorithms. In: Mayer-Kress G (ed) Dimensions and entropies in chaotic systems. Springer, Berlin Heidelberg New York TokyoGoogle Scholar
  11. Hooper J (1983) What lurks behind the wild forces of nature? Ask the connoisseurs of chaos. Omni 5:85–92Google Scholar
  12. Katchalsky AK, Rowland W, Blumenthal R (1974) Dynamic patterns of brain cell assemblies. MIT Press, CambridgeGoogle Scholar
  13. Lorenz EN (1963) Deterministic nonperiodic flow. Atmos. Sci. 20:130CrossRefGoogle Scholar
  14. Mandelbrot B (1977) Fractals, form, chance and dimension. Freeman, San FranciscoGoogle Scholar
  15. Ramos A, Schwartz E, John ER (1976) Evoked potential—unit relationship in behaving cats. Brain Res Bull 1:69–75PubMedCrossRefGoogle Scholar
  16. Röschke J (1986) Eine Analyse der nichtlinearen EEG-Dynamik. Dissertation, University of GöttingenGoogle Scholar
  17. Schroeder MR (1985) Number theory in science and communications. Springer, Berlin Heidelberg New York TokyoGoogle Scholar
  18. Shaw R (1981) Strange attractors, chaotic behaviour, and information flow. Z Naturforsch 36a:80Google Scholar
  19. Takens F (1981) Detecting strange attractors in turbulence. In: Rand A, Young LS (eds) Dynamical systems and turbulence, Warwick 1980. Springer, Berlin Heidelberg New York, pp 366–381 (Lecture notes in mathematics, vol 898)CrossRefGoogle Scholar

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© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • J. Röschke
  • E. Başar

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