1. Intelligence And Cognitive Functioning
CHAPTER 13
Intelligence And Cognitive Functioning
Deficiencies and Disorders of Intelligence

2. Developmental disabilities and mental retardation
The criteria for intellectual disabilities =arbitrary, and based on judgments about the abilities required to get along in our complex world.
In 1978, then 1994, the American Psychiatric Association set the criteria for retardation as a combination of an IQ below 70 points and difficulty meeting routine needs like self-care.
Prior to that, cut off was 85
“cured” thousands of individuals
Not only is any definition arbitrary, but it is situational and cultural as well.
A person considered retarded in our society might fare reasonably well in a simpler environment.
6-hour retarded child

3. DSM IV-TR Levels of Mental retardation
Mild intellectual disabilities
55-70 IQ
Adaptive limitations in 2 or more domains
Moderate intellectual disabilities
35-54 IQ
Severe intellectual disabilities
20-34 IQ
Adaptive limitations in all domains
Profound intellectual disabilities
Below 20 IQ

4. Severity Category
Approximate Percent Distribution of Cases by Severity
DSM-IV Criteria (severity levels were based only on IQ categories)
DSM-5 Criteria (severity classified on the basis of daily skills)
AAIDD Criteria (severity classified on the basis of intensity of support needed)
SSI Listings Criteria (
Mild
85%
Approximate IQ range 50–69
Can live independently with minimum levels of support.
Intermittent support needed during transitions or periods of uncertainty.
IQ of 60 through 70 and a physical or other mental impairment imposing an additional and significant limitation of function
Moderate
10%
Approximate IQ range 36–49
Independent living may be achieved with moderate levels of support, such as those available in group homes.
Limited support needed in daily situations.
A valid verbal, performance, or full-scale IQ of 59 or less
Severe
3.5%
Approximate IQ range 20–35
Requires daily assistance with self-care activities and safety supervision.
Extensive support needed for daily activities.
Profound
1.5%
IQ <20
Requires 24-hour care.
Pervasive support needed for every aspect of daily routines.

5. 2002 AAIDD System: Adaptive Behavior
Refocus on strengths vs. weaknesses
Social Skills
Interpersonal skills
Responsibility
Self-esteem
Practical Skills
Eating
Dressing/Bathing
Mobility
Daily Living tasks

6. Developmental delay and intellectual disabilities
MANY causes
Can be inherited or due to improper cell division
Fragile X
Tay Sachs
Williams Syndrome
Prader Willy
Down Syndrome
Can be caused by diseases contracted during infancy
Meningitis; infection, etc.
prenatal exposure to viruses such as rubella (measles).
Brain injury at prenatally, at birth, before age 2.

7. Developmental delays and intellectual disabilities
Can be due to teratogen exposure
Maternal alcoholism is now the leading cause of preventable intellectual disabilities
Other drugs
Can be caused by prematurity
50% of preterm infants have significant disability
Two most common: Cerebral palsy and intellectual disability
What about autism?
Used to be generically called retardation
Now identify it as separate disorder
Many of individual who would have been diagnosed as retarded are now labeled autistic

8. Down syndrome Down syndrome usually caused by
the presence of an extra 21st chromosome,
Mosaicism: chromosome splits into many small parts
Trisomy 21: chromosonal split resembles presence of 3 21st chromosomes
Related to maternal age, but not necessarily caused by age
Typically results in individuals with IQs in the 40 to 55 range.
Early intervention critical
Early that begin intervention, typically higher the IQ

9. Down syndrome
Amyloid precursor protein gene that involved in early-onset Alzheimer’s disease is located on chromosome 21
was discovered because Down syndrome individuals also develop amyloid plaques.
95% of people with Down syndrome have the entire extra chromosome
In a few cases: only an end portion is present, and attached to another chromosome.

10. Phenylketonuria Phenylketonuria or PKU Without dietary treatment
due to an inherited inability to metabolize the amino acid phenylalanine.
excess phenylalanine interferes with myelination during development.
Without dietary treatment
the individual is severely or profoundly retarded
an adult IQ of around 20 points.
Much more rare today: Postnatal blood tests and routine hospital screenings followed by dietary changes has greatly reduced incidence in this country.

11. Other causes of intellectual disabilities
Hydrocephalus
Water on the brain
occurs when cerebrospinal fluid builds up in the cerebral ventricles.
The increased fluid volume crowds out neural tissue, usually causing brain impairments
Hydrocephalus can be relatively easily treated if caught early
installing a shunt that prevents the accumulation of the excess cerebrospinal fluid.
Eliminate or greatly reduce likelihood of long term brain damage

12. autism Autism is a disorder that typically includes
compulsive, ritualistic behavior
impaired sociability
Language deficits
Often intellectual disabilities
1 in 68 children will receive this diagnosis
Autism is one of 5 autism spectrum disorders
Autism, classic autism, high functioning autism
Autistic Disorder
Asperger Syndrome or Asperger's Disorder
Pervasive Developmental Disorder (PDD),
Autism Spectrum Disorder (ASD).

13. autism Autism diagnosis given based on
Number and particular kinds of symptoms
Severity - mild to severe
Age of onset
Levels of functioning
Challenges with social interactions
Autism is the most common neurological disorder affecting children and one of the most common developmental disabilities

14. autism Asperger’s syndrome People with Asperger’s syndrome are
is the most similar to autism
most likely to share common causes.
People with Asperger’s syndrome are
socially impaired
display repetitive movements
preoccupations with narrow interests like autistic individuals,
But language and cognitive development and self help skills are more normal.

15. Common core of impairment
Whether accompanied by intellectual disability or not, autistic individuals share a common core of impairment in
Communication: often difficulty with communication
Imagination: very literal
Socialization: poor social skills
May be mute or show delayed language development
have trouble understanding verbal and nonverbal communication.
Again, very literal and concrete

16. Brain areas affected in autism
Subtle but widespread brain anomalies have been found,
Especially in the
brain stem,
the cerebellum,
temporal lobes.
The location of damage is inconsistent, which may mean only that there are various pathways to autism.
What causes these brain defects?
is uncertain,
at least we know they occur early, during brain development
So: know where and when to look for the answer.
NOT caused by parental rejection!

17. Autism and environmental influence
Environmental influence: Teratogens?
received the most public attention
generated the greatest controversy is vaccines,
either the MMR vaccine (for measles, mumps, and rubella)
Or mercury as a vaccine preservative.
Research does not support this hypothesis.
Another possibility: Brain damage = autoimmune reaction.
A likely source for such an autoimmunity is viral diseases like measles.
Immune system attacks brain
Could easily be genetic/familial

18. What DO we know? Elevated serotonin levels
biological or biochemical abnormality most consistently found in autistics
One of the genes suspected of playing a role in autism = responsible for the mechanism involved in serotonin reuptake.
Serotonin drugs improve functioning in autism
Supports 5HT model
Changes in serotonin activity suggests that SSRI therapeutic effect is in producing compensatory changes in receptor activity.

19. Ocytocin? Oxytocin referred to as “sociability molecule”
Affects social behavior and bonding in lower animals.
Eyes may provide a strong clue to sociability:
One’s attending to others’ eyes related to oxytocin levels
Individuals with autism avoid eye contact
Individuals with Williams syndrome seek out eye contact
Autistic children found to have lower levels of oxytocin than normal controls
this difference pronounced in the autistic children who were described as aloof.
Thus, may be that low levels of oxytocin are involved

20. Is autism “genetic’ or inherited?
Syndrome vs. a “disease”
Siblings of autistics are 40 to 60 times more likely to be diagnosed with autism than other children.
The number would be even higher, but parents tend to stop having children after the first autistic diagnosis.
Suggests strong familial, if not genetic, link
Autism occurs two to four times more frequently in males than in females,
suggests that the genes for autism might be on the X chromosome
Currently: at least four areas on the X chromosome that are potential sites for autism genes.

21. Theory of mind
Much of social behavior problem may be because autistic person lacks a theory of mind
Ability to attribute mental states to oneself and to others.
An individual with autism cannot infer what other people are thinking.

22. Theory of mind Two hypotheses as to how we develop a theory of mind.
“Theory theory:” We build hypotheses over time based on our experience.
Simulation theory: We gain insight into people’s thoughts and intentions by mentally mimicking the behavior of others.

23. Theory of mind Data tends to support simulation view:
Existence of mirror neurons
Poor imitation skills in individuals with autism
Very different from Williams syndrome
Impaired mirror functions reduces the autistic person’s ability to
Empathize
learn language through imitation

24. How does poor mirror function affect intelligence?
Some individuals with autism show no mirror neuron activity while
Imitating facial expressions
Or when observing a model’s hand movements.
Other studies show reduced activation in the inferior frontal cortex and motor cortex,
Suggests weakness in the dorsal stream connections
Provide important input to those areas containing mirror neurons.

25. Williams syndrome Williams syndrome: first identified in 1961
distinctive, "elfin" facial appearance
unusually cheerful demeanor and ease with strangers;
developmental delay coupled with strong language skills;
profound visuo-spatial impairments;
and cardiovascular problems and transient high blood calcium.
Caused by a deletion of about 26 genes from the long arm of chromosome 7.
It occurs in 1 in 7,500 to 1 in 20,000 births

26. Williams syndrome Number of anomalies:
HIGHER levels of oxytocin than normal
Abnormalities in cerebellum, right parietal cortex, left frontal cortical regions
Increased social behavior may be due to decreased inhibition in dorsal-frontal areas
Some studies show increased mirror neurons
Amygdala:
greater volume than the average
diminished amygdala reactivity in response to socially frightening stimuli (
hyperreactivity in the amygdala when presented with nonsocial fear stimuli (such as frightening animals)

27. Williams syndrome

28. Savant syndrome: Superior abilities? Savant
person with exceptional intellectual skills
beyond the level of “ordinary” genius, like Leonardo da Vinci or Albert Einstein.
term is more frequently used to describe individuals who have one or more remarkable skills but whose overall functioning is below normal.
Half of these individuals with islands of exceptional capabilities are autistic savants.

29. Savant syndrome:
Superior abilities?

30. How can you be “retarded” and superior?
The source of the autistic savant’s enhanced ability is unknown.
Dehaene (1997):
may be due to intensely concentrated practice,
more typically the skill appears without either practice or instruction
Suggests innate ability.
Ramachandran and Blakeslee (1998): specialized area of the brain becomes enlarged at the expense of others.
Snyder and Mitchell (1999):
savant capabilities within us all,
are released when brain centers that control executive or integrative functions are compromised.
Brain damage studies lend support this hypothesis

31. Take home message
Developmental disorders such as autism and many forms of intellectual disabilities are fairly common
Causes of the impairments are many and varied
Understanding brain differences gives us insight into our own intellectual functioning
Emphasis has turned to strengths rather than weaknesses
Most individuals with a developmental disability will be semi-independent and function well within their limitations
Early intervention is highly beneficial
Matter of figuring out what an individual CAN do, and not what an individual can’t do.

32. Get involved and Be the Change
End the R-Word Campaign
Stop using words such as “retarded” as slurs
Get INVOLVED: Volunteer for Special Olympics:
State Games: June here at ISU

33. Let Me Be Brave in the Attempt”.
“Let me Win. But if I Cannot Win,
Let Me Be Brave in the Attempt”.
Special Olympics Athletes Oath