On considerations of coded summation method to measure a slow vertex response

A slow vertex response (SVR) is one of the auditory evoked responses that are measured by electroencephalography (EEG) using the averaged summation method. The use of a coded summation method to measure a SVR is reported. The coded summation method consists of two main steps: the first step is to map original data to coded data, and the second is to sum up and average the coded data. The coded summation method decreases the number of summations to 1/4-1/10 of that used in the usual averaged summation method. The number of coding levels used to map the original data to coded data, assuming a model that has the major characteristics of original data, is discussed. The model is described, and experimental results showing the effectiveness of the coded summation are given