Neuropsychology is a branch of psychology which focuses on the relationship between brain function, behaviors, thoughts, and emotion. A wide variety of injuries, illnesses, and disorders can impact how the brain functions, sometimes temporarily and sometimes permanently. By applying their knowledge of psychology, neuroscience, and brain-based disorders, neuropsychologists help their clients and their client's families, caregivers, educators, and healthcare providers better understand brain dysfunction and cope with it.

Just as neuroimaging techniques like MRI or CT scans can be used to gain information regarding the structural health of the brain, a neuropsychological evaluation can be used to provide information regarding its functional abilities. In other words, a neuropsycholgical evaluation provides information about what the brain can do, rather than what it looks like. This is a particularly useful and powerful tool when information is needed about complex cognitive functions like memory, attention, or problem solving.

Neuropsychologists gather information regarding a client's abilities through carefully collected clinical history and the use of standardized tests and assessments. History provides important information regarding how the individual's current presentation has developed or changed over time, as well as how environmental factors may be impacting their performance. Testing allows neuropsychologists to gain a better understanding of what an individual is currently able to do, how an individual's abilities compare to others, and how the individual applies their abilities. Past medical or educational records are also routinely reviewed as part of a neuropsychological evaluation.

Using the information gathered through their evaluation, neurospychologists then provide their patient with recommendations that can be used to improve their day to day lives. They can also provide their patient's care team with recommendations that can be of assistance in planning for each client's future, including specific recommendations addressing rehabilitation, education, work, and other life goals. Neuropsychologists also function as therapists, working to help patients to adjust to their condition, learn new skills and behaviors, or cope with emotional difficulties.