SELAVCO: a method to deal with trial-to-trial variability of evoked potentials

The possibility and the potential dangers of the inhomogeneity of potentials to repeated stimuli have been recognized for some time. The predominant method of averaging sweeps of brain activity time locked to the stimuli relies on the assumption of an invariant response. In this paper, a method is proposed for dealing more effectively with the variability of single potentials than does averaging. This method operates by weighted averaging and the weights are determined from the data after suitable filtering operations. SELAVCO is validated and compared to the average for real data and in a controlled design close to reality.