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Signal Processing in Neuroinformatics. EEG Signal Processing. Yongnan Ji. Modeling the EEG signal. Artifacts in the EEG. Nonparametric Spectral Analysis. Model-based spectral Analysis. Modeling the EEG signal. Stochastic. Deterministic VS. Nonlinear Modelling of EEG.
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Signal Processing in Neuroinformatics EEG Signal Processing Yongnan Ji
Modeling the EEG signal. • Artifacts in the EEG. • Nonparametric Spectral Analysis. • Model-based spectral Analysis.
Modeling the EEG signal. Stochastic Deterministic VS Nonlinear Modelling of EEG Linear Stochastic Models ARMA, AR Time-varing AR modelling Multivariate AR modelling AR modelling with impulse input
Artifacts in the EEG. Types of artifacts usually met Eye movement and blinks, Muscle activity, Cardiac activity, Electrodes and equipment • Artifact Reduction Using Linear Filtering. • Artifact Cancellation Using Linear Combined Reference Signals. • Adaptive Artifact Cancellation Using Linearly Combined Reference Signals • Artifact Cancellation Using Filtered Reference Signals Artifact Processing Additive noise or multiplicative noise How to deal with the artifact?
Nonparametric Spectral Analysis • Fourier-based Power Spectrum Analysis • We can calculate an estimation of the power spectrum from the samples of the signal: • Mean and variance of the estimation changes against the selection of windows. • Spectral Parameters • Spetral slope. • Hjorth descriptors. • Spectral Purity Index.
Model-based Spectral Analysis • Variance of the input noise. • Methods to find the coefficients of the linear algorithm: • The Autocorrelation/Covariance Methods: Minimization of the error variance. • The Modified Covariance Method: The variance is calcutated taking into acount backward prediction error. • Burg’s Method: We explicitly make use of the recursion method.Estimation with lattice structure.
Performance and Paramerters • Performance. • Choosing method. • Model order. • Sampling rate. • Parameters.
Exercise 3.7 Fourier Transform
Exercise 3.7 Inverse-Fourier Transform