Neurocognitive functions are cognitive functions closely linked to the function of particular areas, neural pathways, or cortical networks in the brain, ultimately served by the substrate of the brain's neurological matrix. Therefore, their understanding is closely linked to the practice of neuropsychology and cognitive neuroscience – two disciplines that broadly seek to understand how the structure and function of the brain relate to cognition and behaviour.
Neuropsychology is a branch of psychology concerned with how a person's cognition and behavior are related to the brain and the rest of the nervous system. Professionals in this branch of psychology often focus on how injuries or illnesses of the brain affect cognitive and behavioral functions.
Rehabilitation of sensory and cognitive function typically involves methods for retraining neural pathways or training new neural pathways to regain or improve neurocognitive functioning that have been diminished by disease or trauma. The main objective outcome for rehabilitation is to assist in regaining physical abilities and improving performance. Three common neuropsychological problems treatable with rehabilitation are attention deficit/hyperactivity disorder (ADHD), concussion, and spinal cord injury. Rehabilitation research and practices are a fertile area for clinical neuropsychologists, rehabilitation psychologists, and others.
Neuropsychological tests are specifically designed tasks that are used to measure a psychological function known to be linked to a particular brain structure or pathway. Tests are used for research into brain function and in a clinical setting for the diagnosis of deficits. They usually involve the systematic administration of clearly defined procedures in a formal environment. Neuropsychological tests are typically administered to a single person working with an examiner in a quiet office environment, free from distractions. As such, it can be argued that neuropsychological tests at times offer an estimate of a person's peak level of cognitive performance. Neuropsychological tests are a core component of the process of conducting neuropsychological assessment, along with personal, interpersonal and contextual factors.
Cognitive neuropsychology is a branch of cognitive psychology that aims to understand how the structure and function of the brain relates to specific psychological processes. Cognitive psychology is the science that looks at how mental processes are responsible for the cognitive abilities to store and produce new memories, produce language, recognize people and objects, as well as our ability to reason and problem solve. Cognitive neuropsychology places a particular emphasis on studying the cognitive effects of brain injury or neurological illness with a view to inferring models of normal cognitive functioning. Evidence is based on case studies of individual brain damaged patients who show deficits in brain areas and from patients who exhibit double dissociations. Double dissociations involve two patients and two tasks. One patient is impaired at one task but normal on the other, while the other patient is normal on the first task and impaired on the other. For example, patient A would be poor at reading printed words while still being normal at understanding spoken words, while the patient B would be normal at understanding written words and be poor at understanding spoken words. Scientists can interpret this information to explain how there is a single cognitive module for word comprehension. From studies like these, researchers infer that different areas of the brain are highly specialised. Cognitive neuropsychology can be distinguished from cognitive neuroscience, which is also interested in brain-damaged patients, but is particularly focused on uncovering the neural mechanisms underlying cognitive processes.
Clinical neuropsychology is a sub-field of cognitive science and psychology concerned with the applied science of brain-behaviour relationships. Clinical neuropsychologists use this knowledge in the assessment, diagnosis, treatment, and or rehabilitation of patients across the lifespan with neurological, medical, neurodevelopmental and psychiatric conditions, as well as other cognitive and learning disorders. The branch of neuropsychology associated with children and young people is pediatric neuropsychology.
Neuropsychological assessment was traditionally carried out to assess the extent of impairment to a particular skill and to attempt to determine the area of the brain which may have been damaged following brain injury or neurological illness. With the advent of neuroimaging techniques, location of space-occupying lesions can now be more accurately determined through this method, so the focus has now moved on to the assessment of cognition and behaviour, including examining the effects of any brain injury or neuropathological process that a person may have experienced.
The Tower of London test is a test used in applied clinical neuropsychology for the assessment of executive functioning specifically to detect deficits in planning, which may occur due to a variety of medical and neuropsychiatric conditions. It is related to the classic problem-solving puzzle known as the Tower of Hanoi.
Edith F. Kaplan was an American psychologist. She was a pioneer of neuropsychological tests and did most of her work at the Boston VA Hospital. Kaplan is known for her promotion of clinical neuropsychology as a specialty area in psychology. She examined brain-behavioral relationships in aphasia, apraxia, developmental issues in clinical neuropsychology, as well as normal and abnormal aging. Kaplan helped develop a new method of assessing brain function with neuropsychological assessment, called "The Boston Process Approach."
Autotopagnosia from the Greek a and gnosis, meaning "without knowledge", topos meaning "place", and auto meaning "oneself", autotopagnosia virtually translates to the "lack of knowledge about one's own space," and is clinically described as such.
Mild cognitive impairment (MCI) is a neurocognitive disorder which involves cognitive impairments beyond those expected based on an individual's age and education but which are not significant enough to interfere with instrumental activities of daily living. MCI may occur as a transitional stage between normal aging and dementia, especially Alzheimer's disease. It includes both memory and non-memory impairments. The cause of the disorder remains unclear, as well as both its prevention and treatment, with some 50 percent of people diagnosed with it going on to develop Alzheimer's disease within five years. The diagnosis can also serve as an early indicator for other types of dementia, although MCI may remain stable or even remit.
Muriel Elaine Deutsch Lezak was an American neuropsychologist best known for her book Neuropsychological Assessment, widely accepted as the standard in the field. Her work has centred on the research, assessment, and rehabilitation of brain injury. Lezak was a professor of neurology at the Oregon Health and Science University School of Medicine.
The California Verbal Learning Test (CVLT) is one of the most widely used neuropsychological tests in North America. As an instrument, it represents a relatively new approach to clinical psychology and the cognitive science of memory. It measures episodic verbal learning and memory, and demonstrates sensitivity to a range of clinical conditions. The test does this by attempting to link memory deficits with impaired performance on specific tasks. It assesses encoding, recall and recognition in a single modality of item presentation (auditory-verbal). The CVLT is considered to be a more sensitive measure of episodic memory than other verbal learning tests. It was designed to not only measure how much a subject learned, but also reveal strategies employed and the types of errors made. The CVLT indexes free and cued recall, serial position effects, semantic clustering, intrusions, interference and recognition. Delis et al. (1994) released the California Verbal Learning Test for Children (CVLT-C). The California Verbal Learning Test-II (CVLT-II) is an updated version of the original CVLT, which has been standardized and provides normative data.
The Halstead–Reitan Neuropsychological Test Battery (HRNB) and allied procedures is a comprehensive suite of neuropsychological tests used to assess the condition and functioning of the brain, including etiology, type, localization and lateralization of brain injury. The HRNB was first constructed by Ward C. Halstead, who was chairman of the Psychology Department at the University of Chicago, together with his doctoral student, Ralph Reitan. A major aim of administering the HRNB to patients was if possible to lateralize a lesion to either the left or right cerebral hemisphere by comparing the functioning on both sides of the body on a variety of tests such as the Suppression or Sensory Imperception Test, the Finger Agnosia Test, Finger Tip Writing, the Finger Tapping Test, and the Tactual Performance Test. One difficulty with the HRNB was its excessive administration time. In particular, administration of the Halstead Category Test was lengthy, so subsequent attempts were made to construct reliable and valid short-forms.
The Luria–Nebraska Neuropsychological Battery (LNNB) is a standardized test that identifies neuropsychological deficiencies by measuring functioning on fourteen scales. It evaluates learning, experience, and cognitive skills. The test was created by Charles Golden in 1981 and based on previous work by Alexander Luria that emphasizes a qualitative instead of quantitative approach. The original, adult version is for use with ages fifteen and over, while the Luria–Nebraska Neuropsychological Battery for Children (LNNB-C) can be used with ages eight to twelve; both tests take two to three hours to administer. The LNNB has 269 items divided among fourteen scales, which are motor, rhythm, tactile, visual, receptive speech, expressive speech, writing, reading, arithmetic, memory, intellectual processes, pathognomonic, left hemisphere, and right hemisphere. The test is graded on scales that are correlated to regions of the brain to help identify which region may be damaged. The Luria–Nebraska has been found to be reliable and valid; it is comparable in this sense to other neuropsychological tests in its ability to differentiate between brain damage and mental illness. The test is used to diagnose and determine the nature of cognitive impairment, including the location of the brain damage, to understand the patient's brain structure and abilities, to pinpoint causes of behavior, and to help plan treatment.
Hold tests are neuropsychological tests which measure abilities which are thought to be largely resistant to cognitive decline following neurological damage. As a result, these tests are widely used for estimating premorbid intelligence in conditions such as dementia, traumatic brain injury, and stroke.
The Delis–Kaplan Executive Function System (D-KEFS) is a neuropsychological test used to measure a variety of verbal and nonverbal executive functions for both children and adults. This assessment was developed over the span of a decade by Dean Delis, Edith Kaplan, and Joel Kramer, and it was published in 2001. The D-KEFS comprises nine tests that were designed to stand alone. Therefore, there are no aggregate measures or composite scores for an examinee's performance. A vast majority of these tests are modified, pre-existing measures ; however, some of these measures are new indices of executive functions.
The Wechsler Test of Adult Reading (WTAR) is a neuropsychological assessment tool used to provide a measure of premorbid intelligence, the degree of Intellectual function prior to the onset of illness or disease.
The Addenbrooke's Cognitive Examination (ACE) and its subsequent versions are neuropsychological tests used to identify cognitive impairment in conditions such as dementia.
Ralph M. Reitan was an American neuropsychologist and one of the founding fathers of American clinical neuropsychology having brought the notion of brain-behavior relationships to the forefront of the field. He is best known for his role in developing the Halstead-Reitan Neuropsychological Battery and his strong belief in empiricism and evidence-based practice. He was a strong advocate of use of a fixed battery in neuropsychological assessment, published prolifically, and mentored many students who also became prominent in the field. As an author, he has been collected by libraries.
