1. A method of building a classifier for multimodal assessment of a subject's neurological condition, comprising the steps of: providing a signal processing device operatively connected to a memory device storing results of two or more different assessments performed on a plurality of individuals in the presence or absence of brain abnormalities, the signal processing device comprising a processor configured to perform the steps of: extracting quantitative features from the results of the two or more different assessments; storing the extracted features in a pool of selectable features; selecting a subset of features from the pool of selectable features to construct the classifier; and determining classification accuracy of the classifier by using it to classify data records having a priori classification information.