ISSN:
1573-6792
Keywords:
Principal components
;
Isotropicity
;
Complex statistics
;
Electroencephalography
;
Equivalent dipoles
;
Fourier analysis
;
Brain mapping
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The structure of the normal resting EEG crosspectrum Svv(ω) is analyzed using complex multivariate statistics. Exploratory data analysis with Principal Component Analysis (PCA) is followed by hypothesis testing and computer simulations related to possible neural generators. The Svv(ω) of 211 normal individuals (ages 5 to 97) may be decomposed into two types of processes: the ξ process with spatial isotropicity reflecting diffuse, correlated cortical generators with radial symmetry, and processes that seem to be generated by more spatially concentrated, correlated sources. The latter are reflected as spectral peaks such as the process. The eigenvectors of the ξ process are the Spherical Harmonic Functions which explains the recurring pattern of maps characteristic of the spatial PCA of qEEG data. A new method for estimating sources in the frequency domain which fits dipoles to the whole crosspectrum is applied to explain the characteristics of the localized sources.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01135568
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