focusing on performance and verbal scales

1. Wechsler Adult
Intelligence Scale
IV-
Verbal and Performance
IQ

2. Verbal Intelligence Quotient
• Verbal intelligence quotient (IQ) measures an individual’s ability to use language
to analyze and solve problems.
• It includes the ability to listen to, analyze, remember, and understand information
in either verbal or written form.
• Skills such as reasoning and the grasp of both abstract and concrete ideas, and
includes their overall understanding of concepts, comparisons, and other similar
characteristics of language, too are measured.
• Verbal skills may also be measured on an academic level. The tests can be
administered individually or in a group setting.
• Included are 7 tests and provided 2 sub indexes- verbal comprehension and
working memory.

3. Verbal Comprehension
Index (VCI)
 VCI intends to measure the
verbal concept formation
 As well as, assesses the ability to
question, infer from learned
information, reason to create
responses and express thoughts
verbally.
 It involves 4 subtests-
1) Similarities
2) Vocabulary
3) Comprehension
4) Information
Working Memory Index
(WMI)
 Blackboard of the mind.
 Measure ability to memorize new
information, concentrate,
manipulate that information to
produce some result.
 Important in higher order
thinking, learning and
achievement.
 The subtests involved are-
1) Arithmetic
2) Digit Span
3) Letter number sequencing

5. Performance
Intelligence
Quotient
• PIQ consists of 6 subtests which provide 2 sub indexes – perceptual reasoning index
(PRI) and processing speed index (PSI).
• The Performance IQ is a measure of fluid reasoning, spatial processing,
attentiveness to details, and visual-motor integration.

6. Perceptual Organization
Index (PRI)
 Measures the non-verbal
(perceptual) and fluid reasoning,
spatial processing, visual-motor
integration, and the ability to learn
new information
 Indicates a preference for visual
information or kinesthetic learning.
 Includes tests like-
1) Block design
2) Matrix reasoning
3) Picture completion
4) Figure Weights
5) Visual puzzles
Processing Speed Index
(PSI)
 Assesses skills on focus, attention,
scanning, discrimination, and
sequentially ordering visual
information
 Measures working under time
pressure and motor coordination
 Related to memory skills,
mathematics, reading.
 Sub tests part of PSI are-
1) Digit-symbol coding
2) Symbol search

8. VIQ > PIQ by 15
points!
 Guertin, Ladd, Frank, Rabin,
and Hiester (1966) reviewed a
number of studies suggesting
that lower PIQ stores are
indicative of right hemisphere
pathology
 It could also result of
misinterpretation.
 Also indicative of traumatic
brain Injury.
 Findings are inconclusive.

9. PIQ outruns VIQ by 15
Runs…err, Points!
 lower VIQ scores are indicative of damage to the left hemisphere, Reitan
(1955) and of Klove and Reitan (1958).
 The results indicate that Visual Puzzles is not a pure measure of visuo-
perceptual reasoning, because memory, mental flexibility, processing
speed, and language abilities also contribute to successful performance of
the task.
 Symbol search was associated with greater activity in bilateral medial
occipital, occipito-parietal, occipito-temporal, parietal, and dorso-lateral
prefrontal cortices (DLPFC). Across both tasks, slower processing speed
was also related to greater activity in these areas, except right DLPFC.

10. Discrepancy
Between Verbal
IQ and
Performance IQ

12. • The discrepancy has been associated specifically with a variety of
verbal, motor, peri-natal, and neurological problems in reports by
Holroyd (1968).
• Although Wechsler (1974) stated that a VIQ-PIQ score difference of 15
points is important and although Cronbach (1961) agreed that the VIQ-
PIQ score has an estimated reliability (.74 at the 99% level of
confidence), he pointed out that one quarter of the WISC-R
standardization sample had VIQ-PIQ discrepancy scores of 15 or more
and cautioned the clinician to use a "statistical abnormality" criterion
for diagnostic or educational purposes
• Lezak -a pattern of clear-cut differences between subtests involving
primarily verbal functions on the one hand and those involving
primarily visuo-spatial functions on the other is likely, but not
necessarily, a product of lateralized brain injury.
• Although Wechsler's intelligence scales were not originally designed as
neuropsychological tests, the verbal and performance IQ scores
measures of functions that are primarily lateralized in the two cerebral
hemispheres (Kolb & Whishaw, 1985).

13. THANK YOU!