Intellectual and Neuropsychological Assessment

3 types of tests

intelligence, achievement, neuropsychological

Intelligence tests

aptitude or intellect: may or may not include speed of mental processing, sensory capacity, abstract thinking, imagination, adaptability, capacity to learn through experience, memory, reasoning, or inhibition of instinct

Achievement tests

what a person has accomplished especially in academic subjects such as math, reading, science, and social studies

Neuropsychological tests

focus on issues of cognitive or brain dysfunction, including the effects of brain injuries and illnesses

intelligence (Gottfredson, 1997)

the ability to direct one’s thinking, adapt to one’s circumstances, and learn from one’s experiences

Intelligence (Pinker, 1997)

the ability to attain goals in the face of obstacles by means of decisions based on rational rules

Charles Spearman

stated that intelligence was a single characteristic and labeled it “g” for general intelligence or a person’s global intellectual ability; acknowledged specific abilities which he labeled “s” that played a minor role in intelligence

Louis Thurstone

intelligence is numerous distinct abilities that have little relationship to one another; Thurstone was a pioneer of multiple factor analysis and found the independent factors of verbal comprehension, numerical ability, spatial reasoning, and memory

According to Thurstone

if you know someone’s ability in one skill you can’t predict with confidence how capable that person will be in another skill

Spearman & Thurstone’s compromise

Hierarchical model of intelligence: specific abilities (s) exist and are important but they are all at least somewhat related to one another and a global intelligence (g)

James Cattell

proposed concepts of fluid intelligence and crystalized intelligence which fall somewhere b/w Spearman’s theory of singular intelligence and Thurstone’s theory of many intelligences

fluid intelligence

the ability to reason when faced with novel problems

crystalized intelligence

the body of knowledge one has accumulated as a result of life experiences

John Carroll

Three-Stratum Theory of Intelligence: intelligence operates at 3 levels (a single “g” at the top, eight broad factors immediately beneath g, more than 69 highly specific abilities beneath these broad factors); most psychologists mirror this view but with possibly fewer specific abilities

David Wechsler

Wechsler Adult Intelligence Scale (WAIS-IV), Wechsler Intelligence Scale for Children (WISC-V), Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV); each test is the most highly respected & popular among clinical psychs for its respective age range

Wechsler Tests

employ a hierarchical model of intelligence; single full-scale intelligence score that reflects a general, global level of intelligence (g) and 4 or 5 index scores and subtest scores that reflect increasingly specific areas of ability (s)

a hierarchical model of intelligence allows clinical psychs to

focus broadly or narrowly when making interpretations regarding intellectual ability

Wechsler tests are administered

one-on-one and face-to-face; are not entirely pencil-and-paper tests that examinees can administer themselves

administration is a

structured interpersonal interaction that requires extensive training that is typically received during graduate programs in clinical psych

each subtest is

brief (2-10 mins), increase in difficulty as the subtest progresses so that ppl continue until they fail a predetermined number of consecutive items, nature of the tasks varies widely (includes verbal and nonverbal tasks)

Wechsler tests originally designed

only verbal and performance subtests (performance was equivalent to nonverbal)

4 subtest factors

verbal comprehension index, perceptual reasoning index, working memory index, processing speed index

verbal comprehension index

a measure of verbal concept formation and verbal reasoning

perceptual reasoning index

a measure of fluid reasoning, spatial processing, and visual-motor integration

working memory index

a measure of the capacity to store, transform, and recall incoming information and data in short-term memory

processing speed index

a measure of the ability to process simple or rote info rapidly and accurately

Wechsler tests feature large, carefully collected sets of

normative data that includes norms from around 2,000 ppl that match recent U.S. census data regarding gender, age, race/ethnicity, geographic region, etc

normative data

a sample of test-result data gathered by creators of a psychological test and typically designed to accompany the test that constitutes a basis for comparison for individuals who take the test in clinical settings

full scale and index scores for Wechsler tests are

IQ scores that reflect intelligence quotient, division (age range expectations), mean IQ scores (full scale and index) are 100, standard deviation is 15

general approach to interpreting scores

• first consider the full-scale IQ score

• next interpret each index score in relation to the others (this will look for relative deficiencies)

• finally, note details of testing; observable patterns of behavior that may have contributed to performance (ex: fatigue, anxiety, lack of motivation, etc)

successive steps allow assessor to grasp the “big picture” of the profile before going into details

Wechsler tests are used for specific clinical contexts

• intellectual disability (intellectual developmental disorder)

• developmental delays

• giftedness

• educational and vocational planning

• school placement and qualification

Wechsler tests are used for broader clinical contexts

comprehensive assessments of clients presenting with many problems

• neuropsychological (ex: Alzheimer’s Disease)

• emotional (ex: mood disorders)

• behavioral (ex: ADHD)

Strengths of Wechsler tests

• impressive reliability and validity

• feature comprehensive and recent normative data

• cover a wide age range

• provide full-scale, index, and subtest scores that have great clinical utility

• most psychologists are familiar with them

Criticisms of Wechsler tests

• some subtests may be culturally loaded or biased

• connection b/w tests and day-to-day life (ecological validity) may be limited

• scoring can be complex on some subtests

Stanford-Binet Intelligence Scales-V similarities to Wechsler tests

Administered face-to-face and one-on-one

– Employs a hierarchical model of intelligence

• Therefore yields

– A singular measure of full-scale IQ (or “g”)

– Five factor scores

– Many more specific subtest scores

– Features the same means (100) and standard deviations (15) as the Wechsler tests

• True for both full-scale and factor scores

– Psychometric data including reliability and validity are similarly strong

Stanford-Binet Intelligence Scales-V differences from Wechsler tests

– The Stanford-Binet covers the entire life span (ages 2-85+) as a single test

• There are three Wechsler test for three different age ranges

– Normative sample

• Like the Wechsler tests, has a normative sample that matches recent U.S. Census data on important variables

• But, additionally includes normative data from individuals with specific relevant diagnoses

– These include learning problems, intellectual disability, and ADHD

– Subtests include extensions on the low and high ends

• i.e. it has a greater number of very easy and very hard items

• This is an effort to more accurately assess people at the extremes

– Including those who may have intellectual disabilities or be gifted

Stanford-Binet and Wechsler tests also differ in their specific factors and subtests

– Wechsler tests feature four or five factors, each yielding an index score

– The Stanford-Binet features exactly five subtests

• Fluid Reasoning

– the ability to solve novel problems

• Knowledge

– general information accumulated over time via personal

experiences, including education, home, and environment

• Quantitative Reasoning

– the ability to solve numerical problems

• Visual-Spatial Processing

– the ability to analyze visually presented information

• Working Memory

– the ability to hold and transform information in short-term memory

– Each of these are measured both verbally and nonverbally

WAIS scores predict a wide variety of important life outcomes

• income

• amount of education someone will receive

• time spent in school and performance in school (correlation b/w IQ and academic performance is 0.50)

• performance at jobs

• health

• less likely to smoke or drink

• more likely to exercise and eat well

• age and longevity

• more satsifying relationships and better mental health

• less racist, less sexist, less likely to commit crimes

• more attentive to benefits of long-term cooperation and less tempted to exploit others

Every 15 point increase in a young person’s IQ is associated with a

24% decrease in his or her ultimate risk of death from a wide variety of causes

– Including cardiovascular disease, suicide, homicide, and accidents

intelligent ppl are more

attractive

only bad trait associated with high IQ

worse eyesight

Deary, Pattie, & Starr (2013)

– Gave Scottish ninety-year-olds the same intelligence tests they took as eleven-year-olds in 1921

– The results were highly correlated

• Preteens who scored highly turned into old people who scored highly

Kell, Lubinski, & Benbow (2013)

– Took 320 children who were tested before the age of thirteen and were in the top 1% of verbal and mathematical skills

– 20 years later, they were more likely to become scientists, journalists, politicians, CEO’s and leaders in society

Lubinski, Benbow, & Kell (2014)

– Looked at thirteen-year-olds who were in the top 1% in mathematical reasoning

– Four decades later

• They were overrepresented as attorneys, top executives, and tenured professors

• They wrote more books, secured more patents, and so on

Intelligence refers to a person’s cognitive capacity

Intelligence is what a person can accomplish intellectually

Achievement refers to what a person has accomplished

– Especially in the kinds of subjects that people learn in school

» e.g. reading, spelling, writing, or math

– Tests typically produce age- or grade-equivalency scores as well as standard scores

Prior to the DSM-5, learning disabilities were determined in large part by

comparing intelligence and achievement

However, in DSM-5, the terminology has changed – “Learning disability” is now called..

Specific learning disorder: A diagnosis based primarily on the level of academic achievement falling significantly below expected levels of achievement for people of the same age

Achievement tests come in many varieties

– Some measure a single area of achievement in detail

• e.g. the KeyMath or the Gray Oral Reading achievement tests

– Some are more comprehensive, featuring a wide rage of subtests, for example

• The Woodcock Johnson Tests of Achievement (WJ)

• The Wide Range Achievement Test (WRAT)

• The Kaufman Test of Educational Achievement (KTEA)

• The Wechsler Individual Achievement Test (WIAT)

Neuropsychological testing

Specialized area within clinical psychology

– Practiced by those with extra training in neuropsychology

• Either during graduate school, predoctoral internship, and postdoctoral internships

The intent of neuropsychological tests is to

measure cognitive functioning or impairment of the brain and its specific components or structures

Medical procedures (e.g. CT, MRI, and PET scans) can indicate

that part of the brain looks abnormal

Neuropsychological tests show

how that part of the brain is actually functioning

neuropsychological testing is useful for the assessment of problems that might arise from

– A head injury

– Prolonged alcohol or drug use

– Degenerative brain illness

neuropsychological tests can be used to make

– A prognosis for improvement

– Plan rehabilitation

– Determine eligibility for accommodations at school or work

– Establish a baseline of neuropsychological abilities to be used as a comparison at a later time