A simulation study of the efficacy of stepwise discriminant analysis in the detection and comparison of event related potentials.

Cortical average evoked potentials were simulated by summing five damped sinusoids. The characteristics of these "evoked" responses could be manipulated by changing parameters of the sinusoids. The synthesized signals were mixed with noise processes whose power and band-width were manipulated. Thus data were generated to stimulate a variety of conditions which could conceivably occur in an experiment on evoked potentials. Stepwise discriminant analysis (BMD07M) has been applied to these simulated data in an attempt to determine the degree to which the program identifies, in a sensible manner, the differences we introduced into the synthesized evoked responses. The simulation results indicate that stepwise discriminant analysis can indeed be an efficacious tool in research on evoked potentials. The program does detect differences in evoked potentials. It can be used, with some reservations, to identify the components of an evoked potential which the experimental variables have affected. In a special set of simulations we have attempted to determine the degree to which stepwise discriminant analysis could serve to detect the presence or absence of an evoked potential. These simulations show that the score of an average evoked potential in the data. The implications of this finding to the use of evoked potentials in sensory sensitivity testing were evaluated in studies for the effect on them of stimulus intensity.