We assessed classifier performance by means of area under the receiver operating characteristic (ROC) curve, denoted Az, (Green and Swets, 1966) using leave-one-out (LOO) cross validation (Duda et al., 2001). Az calculations performed while sliding the window across time enabled observation of the temporal progression of task-relevant components and localization of the stimulus- or response-locked time with maximal discrimination between conditions. To obtain a significance threshold for the Az values, we used a permutation test in which we randomly permuted the trial labels and ran the classifier using the LOO approach. Repetition 1000 times for each subject generated a distribution of Az values from which we computed the Az corresponding to p = 0.01.
