• Corpus ID: 18749467

The evolution with time of the spatial distribution of the largest Lyapunov exponent on the human epileptic cortex

@inproceedings{Iasemidis1991TheEW,
  title={The evolution with time of the spatial distribution of the largest Lyapunov exponent on the human epileptic cortex},
  author={Leonidas D. Iasemidis and J. Chris Sackellares},
  year={1991}
}
The topic of this presentation is the investigation of the epileptic human brain as a nonlinear system that undergoes a phase transition (epileptic seizure). The estimated values of the largest Lyapunov exponent L over time indicated a more chaotic state postictally than ictally or preictally. The start of a seizure corresponds to a simultaneous drop in the values of L at the focal electrode sites. The observed slow cyclic variations in the temporal Lyapunov profiles imply attempts of the… 
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References

SHOWING 1-10 OF 46 REFERENCES
Low-dimensional chaos in an instance of epilepsy.
Using a time series obtained from the electroencephalogram recording of a human epileptic seizure, we show the existence of a chaotic attractor, the latter being the direct consequence of the
Temporal and spatial distribution of intracellular potentials during generation and spread of epileptogenic discharges.
This chapter addresses the characteristics and spatial distribution of intracellular potentials, the spread of paroxysmal depolarization shifts (PDSs) through the cortex, the extracellular field
Structural EEG analysis: an explorative study.
  • B. Jansen, W. Cheng
  • Computer Science
    International journal of bio-medical computing
  • 1988
Ergodic theory of chaos and strange attractors
Physical and numerical experiments show that deterministic noise, or chaos, is ubiquitous. While a good understanding of the onset of chaos has been achieved, using as a mathematical tool the
SPREADING DEPRESSION OF ACTIVITY IN THE CEREBRAL CORTEX
THIS STUDY originated in an attempt to secure more data for the understanding of the cortical electrogram which occurs in “experimental epilepsy,” and of the conditions in which it is brought forth
...
...