Dimensionality of evoked potentials
Gerard J. H. Uijen, Dick F. Stegeman · 2002
The number of independent signals present in averaged evoked potentials (EP) can be determined by means of singular value decomposition. It is shown that a simple cutoff in the order of singular values by using the noise level as a threshold is not satisfying due to large spatial and temporal correlations in the noise. The method of choice is the use of an information theoretic criterion (MDL) applied to the decorrelated data matrix. The decorrelation matrix is obtained from the single sweeps of data after subtraction of the average.>