INTELLIGENCE,IQ ,IQ TESTS &PRE-MORBID IQ

ALI. PKCENTRAL INSTITUTE OF PSYCHIATRYRANCHIALIPKPSY@GMAIL.COM

WECHSLER’S DEFINITION Intelligence is the aggregate or global

capacity of the individual to act purposefully, to think rationally, and to deal effectively

with the environment.

THEORIES OF INTELLIGENCE Spearman – g factor & s factor Gardner – 8 separate “intelligences” Sternberg – triarchic theory of intelligence

Contextual Experiential Componential

Thurstone ‘s view

7 “primary mental abilities”

1. Spatial ability2. Perceptual speed 3. Numerical reasoning4. Verbal meaning5. Word fluency6. Memory 7. Inductive reasoning

CATTELL’S VIEW Fluid Intelligence

The ability to think on the spot and solve novel problems The ability to perceive relationships The ability to gain new types of knowledge

Crystallized Intelligence Factual knowledge about the world

The skills already learned and practiced Examples

Arithmetic facts Knowledge of the meaning of words State capitals

WHAT IS IQ?

Intelligence quotient (IQ): A numerical measure of a person’s performance on an intelligence test relative to the performance of other examinees

Test Norms: standards of normal performance on IQ tests based on the average & range of scores of a large, representative sample of test takers

IQ = MA/CA *100

ALFRED BINET Lawyer, self taught in psychology,

studied under Charcot (who also influenced Freud)

Asked by French government to create a test to identify students who would benefit from remedial education

Along with Theodore Simon, created first widely-used standardized test of intelligence, the Simon-Binet Scale

Lewis Terman: Divided child’s mental age by the child’s chronological age to yield an Intelligence Quotient (IQ) (idea originally from William Stern, a German psychologist)

Stanford- Binet Intelligence Scale: 1916 Been updated many times David Wechsler: Wechsler Adult Intelligence Scale (WAIS) Wechsler Intelligence Scale for Children (WISC) Wechsler Adult Performance Intelligence Scale (WAPIS) Wechsler Primary and Preschool Scale-Revised (WPPSI-R)

---Probably the best IQ test ---Different subscales (Verbal vs.. Performance)

INTELLIGENCE LEVEL

WHAT IS MENTAL RETARDATION..? Mental retardation refers to significantly sub

average general intellectual functioning resulting in or associated with concurrent impairment in adaptive behavior, and manifested during developmental period.

(NIMH Manual for mental retardation)

Causes of Mental

Retardation

Brain Damage

Socio-cultural Factors

Prenatal Factors

Genetic Factors

THE MOST COMMONLY USED INTELLIGENCE TESTS MAY BE CLASSIFIED INTO THREE TYPES: 1. Schedules of development and socio-

adaptive functioning. 2. Verbal Tests. 3. Non verbal and Performance tests

SCHEDULES OF DEVELOPMENT AND SOCIO-ADAPTIVE FUNCTIONING. 1. Developmental Screening Test (DST): The Developmental Screening Test by Bharat Raj

(1977) is designed to measure mental development of children from birth to 15 years of age by a semi-structured interview with the child and a parent or a person well acquainted with the child.

There are 88 items distributed according to the age scales. It provides Developmental Age, DA and Developmental Quotient (Bharat Raj, 1977).

The Vineland Social Maturity Scale (VSMS):It is developed by Edgar A. Doll in 1935,. The

scale was designed to assess the social competence of individuals of ages from birth to 25 years and above. The Indian adaptation of VSMS, by A.J. Malin, has an age range of birth to 15 years. There are eight domains with 89 items. Scoring of the items gives the information on social age from which the social quotient could be calculated (Malin, 1992).

VERBAL & NON-VERBAL WAIS WAPIS STANFORD BINNET VAIS SFBT

WECHSLER SYSTEM Verbal subtests

Information Similarities Arithmetic Vocabulary Comprehension Digit span Letter-number

sequencing

Performance subtests Picture arrangement Picture completion Block design Object assembly Matrix reasoning Digit symbol Symbol search

Performance IQ is based on: Coding

Copying marks from a code; visual rote learning

Picture Completion Telling what's missing in various pictures

Example: Children are shown a picture, such as a car with no wheels, and are asked: What part of the picture is missing?

Picture Arrangement Arranging pictures to tell a story

Block Design Arranging multi-colored blocks to match printed

design Example: Using the four blocks, make one just like this

Object Assembly Putting puzzles together - measures nonverbal fluid

reasoning Example: If these pieces are put together correctly, they

will make something. Go ahead and put them together as quickly as you can.

PREMORBID INTELLIGENCEPremorbid intelligence is an estimate of a

person's intellectual functioning prior to known or suspected onset of brain disease or

dysfunction.

ASSESSING PRE-MORBID IQHistorical data reflecting past achievementsHistorical records, such as school transcripts, military C-file

and employment records, particularly job performance evaluations, are helpful in establishing the capabilities the individual had prior to the injury

Post-injury test performance.Standardized achievement test results can assist greatly in

making the above estimation process more objectively based

Hold method of estimation.In this approach, the neuropsychologist makes

use of test scores which are resistant to brain injury and frequently well preserved (thus the name "hold" tests) in order to estimate prior level of functioning. Abilities such as vocabulary and reading are examples of cognitive functions, shown to be more resilient to disrupting effects of brain injury, that are typically used to predict premorbid intellectual ability.

NART The NART is administered by giving the subject

the list of 61 words and asking him to read each word aloud: “I want you to read slowly down this list of words starting here and continuing down this column and on to the next. I must warn you that there are many words that you probably won’t recognize, in fact most people don’t know them, so just guess at these, O.K.? Go ahead.”

CHORD DENY ACHE CAPON DEPOT AISLE BOUQUET PSALM

"Best performance method" Rather than using tests which are pre-

determined to be resistant to brain injury, the entire testing record is reviewed and the highest scores, in combination with historical data, are used to make predictions concerning the individual’s prior level of functioning.

Pre-Post assessment.Pre and post functioning data collected from

close informant and comparison is made. VSMS &DST.