title: Electroencephalogram spectral analysis by the direct and indirect methods: a comparison.
abstract: An artificially-created electroencephalogram was used to perform a comparison between the indirect and direct analysis methods. The results obtained by Fourier transform of the correlation function and smoothing of Fourier series development differ for a stochastic process in which the correlation functions are not sufficiently damped. Some mathematical framework is also appended in which the difference is worked out from a more theoretical point of view. In order to obtain results independent of inherent conditions, which in the simplest way can be detected by calculating the correlation functions, the indirect method is preferable.
authors.affiliation: Department of Neuropharmacology, Brain Research Institute, Austrian Academy of Sciences, Währingerstrasse 13a, A-1090 Vienna, Austria.
authors.forename: R H
authors.initials: RH
authors.lastname: Jindra
mesh_terms: D001921:Brain / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods*; D005583:Fourier Analysis; D006801:Humans; D008959:Models, Neurological; D012815:Signal Processing, Computer-Assisted