ANALYSIS OF DIFFERENCES BETWEEN CONDITIONED AND CONTROL REFLEX SERIESIN EMG RECORDINGS

Two methods are presented for the data analysis of signals derived by subtracting conditioned from control reflex data in full-wave rectifie d and averaged electromyographic (EMG) signals. The first method uses the ratios of the mean amplitudes and standard errors of the mean (S.E .M.s) (i.e. Student's t values) of a series of data points in such a d ifference signal, and deals with the detection of latencies of reflex components which are susceptible to a conditioning stimulus or experim ental situation. The second method applies a modified cumulative sum ( CUSUM) technique to full-wave rectified difference signals. This modif ied CUSUM technique determines the magnitude of the effects of the con ditioning situation above that expected due to chance fluctuations, ta king into account the effect of reflex modulations on such chance fluc tuations in a post-stimulus period. The modified CUSUM technique prove d particularly useful when various subtle but consistent, opposing cha nges occurred sequentially in the conditioned series thus yielding a c omplicated pattern of effects in a difference signal, with a low signa l-to-noise ratio.