An apparatus comprises an ERP testing system that is configured to administer an ERP test. The apparatus further comprises a computer in communication with the ERP testing system. The computer is operable to access a database of biomarkers. The computer is further operable to define at least one class set relating to biomarkers and at least one feature set relating to biomarkers. The computer is further operable to classify a test subject into at least one of the defined class sets based on information in the feature set relating to biomarkers of the test subject. The biomarker processing may be carried out in association with or completely independent of ERP testing.
