Neuropsychological test are used in the assessment of persons with known or suspected brain dysfunction. Neuropsychology is the study of brain-behavior relationship. Over the years, neuropsychologists have discovered that certain tests and procedures are highly sensitive to the effects of brain damage. Neuropsychologists use these specialized test and procedures to make inferences about the locus, extent, and consequences of brain damage. A full neuropsychological assessment typically requires three to eight hours of one-on-one testing with an extensive battery of measures. Examiners must undergo comprehensive advanced training in order to make sense out of the resulting mass of test data