Clinical neuropsychology is an applied science of human behavior based on principles of brain–behavior relationships. Central to this approach is neuropsychological assessment, which involves gathering information about an individual’s history, current symptoms and functioning, as well as administering a variety of behavioral measures designed to probe specific cognitive functions. A clinical neuropsychologist integrates objective data within a biopsychosocial context to evaluate and diagnose abnormalities in the realm of behavior and cognition. The assessment may address a variety of clinical questions, often to aid in diagnostic clarification and guide treatment planning.
Neuropsychology emerged from a confluence of disciplines within psychology and clinical neuroscience, with its foundation primarily rooted in three areas: psychophysics, psychometrics, and behavioral neuroanatomy. Psychophysics, the branch of psychology that deals with the relationships between physical stimuli and mental phenomena, and psychometrics, the science of measuring mental processes, established that mental phenomenon could be measured with appropriate methods and test instruments to capture a construct of interest with accuracy and precision. Developing and interpreting neuropsychological tools has been rooted in this methodology and guided by ever-increasing knowledge of brain–behavior relationships. Early advancements in basic neuroscience and functional neuroanatomy helped elucidate the neural mechanisms of brain function and identify associations between brain lesions and resultant abnormalities in cognition and behavior. Spurred in large part by new methodologies in structural and functional imaging, our understanding of the complexity of these relationships expanded steeply, with experimental and clinical practice developing in tandem. The phenomenal growth of clinical neuropsychology over the past half century owes much to contemporaneous work in clinical neuroscience.
Although it is not possible to pinpoint the date of its establishment as a discipline, prior to 1960, there were no professional organizations, journals, or training programs in neuropsychology.1 In its earliest form, neuropsychology was practiced in medical settings in association with departments of neurology and neurosurgery. Psychologists with expertise in psychological measurement and a special interest in behavioral effects of brain injury designed tests to assess various abilities in their patients.
The term “neuropsychology” came into use only relatively recently in the mid-20th century, although theories and cultural musings about the bases of human behavior can be traced back to the writings of the ancients. The Egyptians originally localized the seat of human thought in the heart. This concept remained largely unchallenged for 3000 years, when a student of Pythagoras argued that aspects of mental function were represented in specific regions of the brain. This approach to thinking about the brain was later termed localization and became the center of great controversy 2000 years later. Hippocrates, writing in the 4th century BC, posited that the brain was the organ of intellect, sensation, and emotion. While anomalous human behavior had been attributed to spiritual forces, he conceptualized mental illness as a product of abnormal brain function. Along this line, he advanced the hypothesis ...