Abstract

It is evaluated whether the P300 amplitude for the probe is greater than the P300 amplitude for the irrelevant in the P300 concealed information test. However, there is a problem that the P300 amplitude for the probe is overestimated because the number of trials of the irrelevant is much larger than that of the probe. Rosenfeld et al. (2008) attempted to solve this problem by reducing the bootstrap sample size of the irrelevant to the sample size of the probe. In general, the bootstrap sample size must be the same as the original sample size and the type 1 error rate becomes smaller than the significance level if the bootstrap sample size is smaller than the original sample size. The purpose of this study is to evaluate the type 1 error rate of the modified bootstrap method that reduces the bootstrap sample size of irrelevant through Monte Carlo studies and to check whether this error can be corrected. As a result of experiment 1, the type 1 error rate of the modified bootstrap method was about .073, which was lower than the significance level .10. The type 1 error rate of the adjusted bootstrap method with corrected the significance level using the standard error was about .140 which was higher than the significance level .10. Consequently, the error of the modified bootstrap method was not corrected. In order to investigate the reason why the error of the modified bootstrap method was not corrected, a Monte Carlo study using numbers was performed. In the results of experiment 2, the type 1 error rate of the modified bootstrap method was about .054, which was less than the significance level .10, and that of the adjusted bootstrap method was about .10, which was the same as the significance level. It was found that the reason why the error of the modified bootstrap method is not corrected was due to the specificity of the EEG data. The reasons why these errors are not corrected and how to solve these errors were discussed.