Related Experiment Video
Updated: Aug 16, 2026

Cortical Source Analysis of High-Density EEG Recordings in Children
Published on: June 30, 2014
Current source density estimation and interpolation based on the spherical harmonic Fourier expansion
R D Pascual-Marqui1, S L Gonzalez-Andino, P A Valdes-Sosa
1Neurosciences Branch, National Center for Scientific Research, Havana, Cuba.
Abstract:
A method for the spatial analysis of EEG and EP data, based on the spherical harmonic Fourier expansion (SHE) of scalp potential measurements, is described. This model provides efficient and accurate formulas for: (1) the computation of the surface Laplacian and (2) the interpolation of electrical potentials, current source densities, test statistics and other derived variables. Physiologically based simulation experiments show that the SHE method gives better estimates of the surface Laplacian than the commonly used finite difference method. Cross-validation studies for the objective comparison of different interpolation methods demonstrate the superiority of the SHE over the commonly used methods based on the weighted (inverse distance) average of the nearest three and four neighbor values.
Related Concept Videos
Gauss's Law: Spherical Symmetry
Spherical and Cylindrical Capacitor
Conventionally, considering the symmetry, the electric field between the concentric shells of a spherical capacitor is directed radially outward. The magnitude of the field, calculated by...
Electric Field of a Non Uniformly Charged Sphere
Consider a non-uniformly charged sphere, for which the density of charge depends only on the distance from a point in space and not on the direction. Such a sphere has a spherically symmetrical charge distribution. Here, the electric...
Boundary Conditions for Current Density
Sinusoidal Sources
In homes, the power supplies use sinusoidal sources to provide electricity. These sources generate a voltage that varies sinusoidally...
Reconstruction of Signal using Interpolation

