Neuropsychology is the study of the structure and the function of the brain as it relates to specific psychological processes and behavior. A neuropsychologist is a clinical psychologist whose work focuses on brain behavior relationships. A neuropsychologist conducts tests to determine post-accident intellectual ability and personality. They will review academic and employment records and other such documentation that indicates student and employee traits and characteristics prior to a brain injury accident. They also interview family, friends and acquaintances to further determine personality characteristics prior to the accident. The neuropsychologist then reviews post-accident employment and academic performance to determine whether there has been a negative impact due to the brain injury. Mild brain injury can cause wholly new injuries or aggravate pre-existing behavioral difficulties. Either one can have a significant detrimental impact on the quality of life. The role of the neuropsychologist is to determine the nature and the extent of the brain damage. The neuropsychologist will need to consult with a medical doctor in arriving at the final patient diagnosis.