Wechsler Adult Intelligence Scale: A Neuropsychological Assessment

1. Wechsler Adult Intelligence Scale: A Neuropsychological Assessment CiciliaEviGradDiplSc., M. Psi

2. History • 1939  David Wechsler developed Wechsler Bellevue to evaluate the intellectual functioning of the older child and adult  as an alternative to the Stanford-Binet forms L and M which unsuitable for adults • WB Form I was revised and reissued as Wechsler Adult Intelligence Scale (WAIS)

3. Verbal = Performance IQ • The differences between the two scores provide diagnostic clues  15 points or more as diagnostically significant • Blatt & Allison (1968)  “V-P discrepancy allows the clinicians to describe individual’s unique organization of psychological function and from this to infer the defenses, the nature and quality of drives and impulses, the degree of pathology, as well as his assets and capacities for adaptation and coping”

4. VIQ > PIQ • Characteristics of right-hemisphere or diffuse brain damage, adolescent girls with ovarian dysgenesis (Cohen, 1962), for subjects with low intelligence with ‘infection’ or other CNS pathology (Fisher, 1960), murderers pleading insanity and given a psychotic diagnosis (Kahn, 1968), older black deliquents (Henning & Levy, 1967), black homeless men (Levinson, 1964) • Also considered as a pattern in the bright normal and superior IQ ranges (Blatt & Allison, 1968)

5. VIQ < PIQ • Characteristics of organicity; person with left-hemisphere damage, juvenile delinquents; for runaways and truants and those charged with drinking, theft or murder (Gorotto, 1961); sociopaths (Kahn, 1968) but not for those who pleading insanity as mentioned before; hysteric and narcissistic personalities (Blatt & Allison, 1968)

6. Deterioration Quotient (DQ) • FIQ decreases with increasing age and largely as a result of impaired performances on certain subtests  expanded to include any deterioration attributable to psychosis, brain damage or normal aging process • DQ  ratio between those subtests in which performance remains fairly constant and those in which impaired performance is evident

7. DQ (2) • Formulasiumum: • WAIS DQ = H – DH H • DH  S + D + DS + BD ; H  I + V + PC + OA • Depressive = DH = DS+PC+PA+OA H I + C + A + V • Schizophrenic = DH = D+DS+PA+BD+OA H I+C+S+V+PC • Neurotic and PD = DH = A+DS+BD+OA H C+S+V+PC

8. Information • Measures the amount of general information that the individuals has absorbed from his environment  experiential and reading background • Requires remote memory, greatly affected by age • Intellectual curiosity and motivation, as well as reading habits and auditory comprehension

9. Comprehension • Measures the degree to which the subjects has been able to evaluate accurately a sample of past experiences (incl the vicarious) and apply it to everyday social situations; degree of social acculturation – esp on moral or ethical judgments • Less dependent on formal education than Information subtest, but need to be able to verbalize accurately

10. Arithmatic • Measures cognitive development  through the comprehension of the abstract concept of number; also the non-cognitive (not necessarily nonintellective) factors of attention and concentration • Problem-solving test, a measure of concentration and freedom from distractibility

11. Similarities • Memory, comprehension and capacity for associative thinking  to assimilate similarities and differences in objects, facts and ideas surrounding him and his ability to order the likeness into classes • Involving conceptual judgment to separate essential from non-essential features  to distinguished quality or levels of intellectual

12. Digit Span • Measures immediate auditory recall  attention and freedom from distractibility, particularly from bizarre affects or confused thought processes • Need to have a quick adaptation/flexibility • Fwd > Bwd  poor auditory memory, anxiety, simple inattention, low mental capacity • Fwd < Bwd  a stress-resistant ability to manipulate auditory signals under difficult circumstances, or indicate oppositional tendencies

13. Vocabulary • Measures intelligence  indicate early education and environment, as well as later schooling and life experiences • Sensitive to new information and ideas and ability to store and associatively regroup these as the occasion demands  classificatory and conceptualizing skills • Degree of poverty or richness of thought processes and environment, sensitive to feelings, particularly fears or preoccupation to irrelevant thoughts and bizarre associations

14. Vocabulary (2) • As a pure measure of verbal comprehension for college students (Shaw, 1967), chronic schizophrenic (Berger et al., 1964), chronic brain-damaged patients (Russell, 1972), epileptic (Dennerll et al, 1964) and intellectual disabilities (Taylor, 1964) • Measures the basic requirements for everyday functioning

15. Digit Symbol • Measures the ability to learn an unfamiliar task; visual – motor dexterity, degree of persistence in sticking to an unattractive task and speed of performance • Motor behavior is more important than any other subtests  deficiencies in visual acuity and visual motor coordination  affect performance markedly • Efficient memorization under pressure

16. Picture Completion • Know what is the object or situation represented, particular perspective presented, and the interrelationship between the various major elements that are visible; concentration and resist distraction • Distortion of reality  pointing out tiny gaps in the lines of the sketch, inability to identify simple objects, tendency to designate them in some bizarre scheme • Brain damaged  inability to make identification within time limit

17. Block Design • Cues to intelligence  see meaningful spatial relationships, analyze visually, synthesize abstract geometric designs • Finding a correct solution!  clues to intelligence • Visual-motor integration and speed of processing , concentration, perseverence • Excessive cautiousness, impulsiveness and distractibility  show nonintellective factors

18. Picture Arrangement • Measures visual perception, synthesis into wholes through planning and ability to see cause-effect relationships • Clues to interpersonal relationships and general intelligence to social situations  attending to, recognizing and ordering sequences denoting probable life situations • Cultural background is important

19. Object Assembly • Measures visual analysis and its coordination with simple assembly skills  how effective someone make meaningful combination of parts • Perceptual organization factors  chronic schizophrenic, chronic brain-damaged person, epileptics, other organic groups • Different with BD  in OA there’s no preassembled design and no formal help

20. Brain-Sensitive Subtests • DS/Coding  the most brain-sensitive Wechsler subtest and can be lowered by lesions in any location  speed of processing and/or learning, sequencing, rote learning, concentration, visual-motor abilities • BD  esp to either left or right parietal lesions  visual-spatial problems, difficulty in constructing objects

21. Brain-Sensitive Subtests (2) • PA  lowering is consistent with right anterior temporal and right frontal lesions, some cases caused by left hemisphere lesions  affect following directions and/or conceptual skills • DS and A  lowered in brain-damaged people, esp with left hemisphere lesions  poor concentration and attention

22. Brain-Sensitive Subtests (3) • V, I, PC  rough estimation of premorbid level of functioning because they are relatively unaffected by lesions • Brain-damaged children  low in V score • Low I and V scores  left temporal damage  difficulties with word comprehension, retrieval and language expression • PC  resistant to brain damage

23. Brain-Sensitive Subtests (4) • S  lowered with left frontal lesions  difficulties with verbal reasoning and verbal concept formation • Qualitative responses  might suggest poor judgment and impulsivity, misses easy items but correctly answer the difficult ones (diffuse brain damage), concrete thinking bound by the stimulus value of the item