A note on assessing the stability of eigenvectors (principal components) derived from ERP data

Principal component analysis may be applied to psychophysiological data as a data reduction and modelling technique. Prior to interpreting parameter estimates thus obtained, it is important to gain some insight into their stability. Such information can be acquired by means of a simple method based on a perturbation technique. This method uses the standard output of statistical programs for carrying out PCA and requires very little computation. No assumptions are necessary regarding the distribution of the ERP data or the type of dispersion matrix. An example is given using ERP data.