EEG: Spectral Characteristics vs. Correlation Dimension

In real systems like EEG the chaos is very difficult to prove or exclude. The scepticism against finite dimension estimates is understandable. It is hard to believe that a complicated system as the brain, which is continually interacting with many other complex systems, should manifest as deterministic low-dimensional dynamics. Predominantly, it is a manifestation of a mixture of noise, some cyclic processes and random fractal signals. Each part of such a composition itself is frequently reported to fool the algorithms used to detect chaotic dynamics. Therefore, the correlation dimension estimates should be interpreted with extreme caution.