THE ANALYSIS OF STEADY STATE EVOKED POTENTIALS REVISITED
Hans Strasburger · GoeScholar The Publication Server of the Georg-August-Universität Göttingen (Georg-August-Universität Göttingen) · 1987
Summary-I. This note provides a critical discussion of methods for the analysis of steady state visual evoked potentials. 2. To take advantage of the linearity of the Fourier transform, the results of submitting VEP data to a Fourier analysis are discussed in terms of a vector representation of the VEP frequency components. 3. Methods for VEP data and for assessing VEP variability are described. Vector averaging of spectral data is found preferable over scalar averaging. 4. The influence of noise on VEP amplitude is discussed. 5. Changes in temporal phase of the VEP response can be interpreted as changes in delay or latency provided the appropriate precautions in data analysis are taken. 6. Phase information can also be used to improve the VEP signal-to-noise ratio. This is the goal of phase-sensitive analysis. 7. Synchronous demodulation is a method for narrow bandpass filtering. It is shortly described. 8. Finally it is shown that the techniques of VEP analysis at issue are closely related; the correspon dences are pointed out.