Perspectives and History—Definitions
- Neuropsychology: The study of the relationship between brain function and behavior (how do complex brain properties allow behavior to occur?).
- Neuropsychological Assessment: Non-invasive method of describing brain function based on a patient's performance on standardized tests.
o Cerebral brain lesions, localization, limitations on educational, social or vocational adjustment.
o Can aid with assisting the manner in which an illness or injury progresses.
Perspectives and History—Roles of Neuropsychologists
- Neuropsychologists are called by neurologists to help establish/rule out a specific diagnosis.
o Ex: to rule out a disorder with neurological/emotional basis (what is the basis?)
- Neuropsychologists can make predictions for the prognosis of recovery (due to understanding functional systems of the brain).
- Intervention and rehabilitation for treatment—domains of functioning for rehabilitation.
- Evaluate patients with mental disorders to help predict course of illness and to tailor treatment to patient's strengths and weaknesses.
History of Neuropsychology—Theories of Brain Functioning
- Different time periods have been suggested from Edwin Smith Surgical Papyrus to the Pythagoras and his claim that behavior reactions occur in the brain.
- 19th century—damage to cortical areas has related to impaired functioning of certain behaviors.
o Franz Gall and currently discredited phrenology—differences in intelligence and personality due to bumps and indentations on the skull.
- Localization of Function: Certain brain regions are responsible for specific functions/behaviors.
- Work during this period was being conducted by Broca, Pierre Flourens, Karl Lashley and others.
- Equipotentiality: Though there is localization of function, the cortex functions as a whole and not in isolated units. Damage will impair higher functioning; substitutions can occur for damage.
- Functional Model: Integrates localization of function and Equipotentiality theory, states that areas of the brain interact with each other to produce behavior. Several functions^ behavior, and does not view behavior as the result of discrete brain regions.
- Reorganization: Recovery from brain damage can occur.
History of Neuropsychology—Neuropsychological Assessment
- For a long time viewed brain damage as a unitary phenomenon
- Benton Visual-Retention Test and the Graham-Kendall Memory-for-Designs Test—targeted assessment of absence/presence of brain damage.
- Neuropsychology began to grow after WWII due to extensive number of head injuries, and the development of the field of clinical psychology.
- Wald Halstead—looked at brain damage and characteristics of subsequent behavior; developed a test battery composed of 10 measures through factor analysis. Revised by Ralph Reitan
o Half-Reitan Neuropsychological Test Battery
- Flexible battery approach assessment: Allows each assessment to be tailored to an individual based on the clinical presentation and the hypothesis of the neuropsychologist.
- Standard battery approach assessment: Very structured, time consuming and rarely flexible.
Brain Structure and Function
- Left Hemisphere: Controls right side of the body, involved with language function, logical inference, detailed analysis.
- Right Hemisphere: Controls the left side of the body, involved with visual-spatial skills, creativity, musical activity & perception of direction.
o Communicate via Corpus Callosum that integrates complex behavior.
- Frontal Lobes: Most developed, allows us to compare our behavior & reactions of others in order to obtain feedback and alter our behavior as necessary. Associated with executive functions and emotional control. Development largely occurs in adolescence.
- Temporal Lobes: Linguistic expression, reception and analysis, interpreting of non-verbal cues.
- Parietal Lobes: Tactile and kinesthetic perception, spatial perception, body awareness and a little language understanding.
- Occipital Lobes: Visual processing and visual memory
- Cerebellum: Motor coordination, equilibrium control and muscle tone functioning.
Antecedents or Causes of Brain Damage
- Brain tumors can grow outside, within the brain or can be the result of cells spreading from other body areas.
- Increase in tumor size^ poor memory, affect problems, judgement issues...
- Treatment^ surgery or radiation
- Neuron degeneration in CNS
- Includes Huntington's, Parkinson's, Alzheimer's and Dementia
- Alzheimer's is most common followed by Parkinson's and then Huntington's
- Disturbances—motor, speech, language, memory, judgment
Nutritional Deficiencies and Toxic Disorders
- Malnutrition can lead to neurological and psychological deficits
- Metals, toxins, gases, some plants can be absorbed through the skin^ toxic consequences or brain damage
o Delirium: Disruption of the consciousness
Chronic Alcohol Abuse
- Can lead to tolerance and dependence on the substance; changes in neurotransmitter sensitivity or shrinkage of brain tissue.
- Deficits of Limbic system—memory formation, emotional regulation & sensory integration.
- Diencephalon: Region near center of the brain that includes the bodies of the hypothalamus.
o Shrinkage or lesions in these areas.
- Atrophy of the cerebral cortex & damage to the cerebellum
Consequences and Symptoms of Neurological Damage
- Impaired orientation—difficulty recalling name, day of week, surroundings
- Impaired memory—difficulty recalling loved ones, memories, filling in gaps, learning issues
- Impaired intellectual functions—difficulty with comprehension, speech production, general knowledge
- Impaired judgement—difficulty with decisions
- Shallow and Labile Affect—laughing/weeping easily and switching emotions inappropriately
- Loss of emotional and Mental Resilience—can function in daily life but difficulty functioning under stress (ex: fatigue, mental demands), emotional reactions.
- Frontal Lobe Syndrome: Personality deficits—ex: poor impulse control, planning issues, temper tantrums.
- Important to determine where in the brain the injury occurs, same-size lesions in different brain regions will produce different behavior deficits.
- Brain damage can lead to deficits in visual perception, auditory perception, voluntary motor coordination, memory and other brain regions.
- Clinicians are called to determine level of intellectual deterioration—involves comparison to previous levels of functioning.
o Decline due to psychosocial factors (ex: motivation, emotional issues) or brain injury.
Methods of Neuropsychological Assessment
- Standard Battery Approach/Fixed Battery Approach: Evaluates patients for all basic neuropsychological abilities.
o Very expensive, possibility of patient becoming fatigued, not tailored/inflexible
- Process/Flexible Approach or Hypothesis-Testing Approach: Assessment is tailored to the individual patient and the neuropsychologist chooses specific tests.
o Can be very useful but can also lead to the clinician choosing the wrong test.
Interpretation of Neuropsychological Test Results
- Interpretation in the context of normative data (ex: patient score below average mean score).
- Various methods also include Difference Scores for impairment, Pathognomonic signs of brain damage (failing to draw the left side of a picture), Pattern Analysis & statistical formulas.
- Cutoff scores or absolute scores shoved the most accuracy.
- Neurodiagnostic Procedures: CAT scans, fMRI's, spinal taps and other procedures for detecting the presence and location of brain damage. Variation in expense, sensitivity, risk for patients.
- SPECT & fMRIs assess blood flow changes in the brain; are useful for assessing brain function.
Testing Areas of Cognitive Functioning
- Include WAIS-IV and modified versions of it (ex: adding additional subtests).
- WAIS-R-NI—most information provided for person's cognitive strategies; WAIS-IV most used subtest is the Information, Comprehension and Vocabulary subtests.
o Can be used as baseline—least affected by trauma
- Patients with brain damage approach abstract tasks in a concrete manner.
- Similarities subtests of WAIS-IV and Wisconsin Card Sorting Test (WCST)
Memory and Visual-Perceptual Processing
- Wechsler Memory Scale (WMS/WMS-IV is most recent)
- Performance is assessed with 5 index scores—Auditory, Visual, Visual Working, Immediate and Delayed Memory.
- Discrepancy between scores—contrast scores.
- Benton-Visual Retention Test—test of memory for designs
- Rey-Osterrieth Complex Figure Test—assesses visual-spatial memory (draw a picture from memory & then draw it again after a certain period of time).
- Needed for activities like reading a map, parallel parking; use of certain WAIS-IV subtests.
- Brain damage impacts the production or comprehension of language—repeating words, sentence, difficulties with articulation.
- Language comprehension can be assessed using the Receptive Speech Scale.
The Halstead-Reitan Battery
- Most widely used test-battery, and is made up of several measures (ex: Category Test)
- These tests can be supplemented by the MMPI-2 and the WAIS-IV
- Provides information about the localization of lesions and if they appear to be gradual or of sudden onset.
- This test is very time consuming—takes 6 hours to administer; but highly valid & reliable.
The Luria-Nebraska Battery
- Alternative to Halsterad-Reitan, 269 tasks of 11 subtests. Viewed as reliable & valid.
- High agreement with results found on the Halstead-Reitan Battery.
- Main advantage is unlike the Halstead-Reitan it only takes 2.5 hours to administer
Variables That Affect Performance on Neuropsychological Tests
- Includes biological sex, age and educational level.
- Variables like motivational variables (cooperation, level of arousal).
- Malingering: A motivational variable; refers to faking on psychological tests. It's difficult to detect even for the most knowledgeable clinician.
Intervention and Rehabilitation
- Questions of impairment focus on—nature of the deterioration of damage & is there any form of brain damage that can account for a patient's behavior?
o Focal damage—more specific limited effects on behavior
o Diffuse damage—wide effects on behavior
- Rehabilitation: One of the major functions of neuropsychologists. Rehabilitation tasks are generally formulated to treat the patient's deficits.
Concluding Remarks: Training
- Specialty training is necessary; some psychologists training in neuropsychology is limited so they're no qualified to give assessments.
- Clinical neuropsychology is a subspecialty—trains individuals to understand both typical brain function and brain dysfunction effects.
Concluding Remarks: The Future
- Developing increasingly more sophisticated individuals tests and batteries.
- Better methods of assessment, therapy and rehabilitation—focusing on helping the patient adjust and recover by develop tests that predict extent and rate of injury and rehabilitation programs that offer hope for families and the patient.
- Currently relatively few neuropsychologists have obtained training in rehabilitation.