Determine the term - Validity and reliability
With regard to concurrent validity, the criterion used in most cases is the objective identification of some central nervous system lesion arrived at independently of the neuropsychological test results. Therefore, validation is generally provided by neurologists or neurosurgeons. Historically, identification of lesions of the brain has been problematic because, unlike many organs of the body, the brain cannot usually be visualised directly in the living individual. The major exception occurs when the patient undergoes brain surgery or a brain biopsy. In the absence of these procedures, validation has been dependent on autopsy data or the various brain imaging techniques.