Cognitive Disabilities Test 4

autism spectrum disorder

multiple diagnoses merged

autism, Asperger’s, PDD-NOS

World prevalence of autism

1 in 100

US prevalence of autism

1 in 36

autism x savant prevalence

10% of autistic individuals demonstrate savant skills

autism source

brain abnormalities in the limbic system may be associated with social interaction deficits

source of autistic behaviors

theory of mind

weak central coherence

executive dysfunction

theory of mind

having a certain sense of what others are experiencing

constantly being aware

theory of mind demonstration

sally- ann task

two dolls with two baskets

Sally puts a marble in her basket and leaves the room.

While gone, Ann moves the marble to her own box.

When Sally returns to the room, where will she look for the marble

Sally-Ann task response

typical developing four year old knows that sally will look in her own basket and can explain the reasoning behind why

autistic four year old says sally will look in Ann’s basket even though sally didnt see the event

• they lack the understanding of the motives of a character in a story

• autistic individuals have developed explicit theories of mind used in their reasoning but it does not became an intuitive part of their responding

weak central coherence

normal: suggests that information is processed in context and that higher level meaning is extracted

weak: suggests poor connection between perceptual processes and higher-level modulation.

weak central coherence and story recall

typically people remember the gist but autistic individuals remember details and literal aspects

weak central coherence demonstration

embedded figures test

autistic individuals have a superior performance

test where a part must be isolated from an overall picture

executive dysfunction

includes a number of WM tasks: planning, shifting set, impulse control, action monitoring

autism→ deficits in these tasks

autism WM deficits (Executive dysfunction)

rigid and perseverative behaviors

limited initiation of new activities

tendency to be “stuck” in a specific task set

strong preference for routine and repetitive behavior

NOT unique to Autism and can be seen in other disorders

executive dysfunction demonstration

Wisconsin card sorting

individuals are asked to sort cards into different groups but the required basis for sorting changes without specific identification of the sorting criteria but with feedback on each card

autistic individuals tend to perseverate longer on a previous strategy that is no longer successful

non-social autism deficits

repetitive, obsessive and narrowly focused behaviors

uneven patterns of intelligence

• good performance: assessments of rote memory, factual knowledge, detailed attentional focus

• poor performance: task planning, WM, “common sense” comprehension

Savants

an individual with exceptional ability in one or more fields that co-exist with some form of disability

savant syndrome underlying disorder

autism in 50% of cases

#1 predominant extraordinary skill in savants

calendar calculating

almost always present

includes complex calculations as well as memory

#2 predominant extraordinary skill in savants

music

typically performance; normally accompanied by perfect pitch

ability to play entire pieces after single hearing

“musical triad” blindness, mental impairment, musical genius

#3 predominant extraordinary skill in savants

art

extensive literal memory

typically evident at early age

#4 predominant extraordinary skill in savants

mathematical and number skills (lightning calculating)

prime number and square root facility

complex multiplication but absence of simple arithmetic

#5 predominant extraordinary skill in savants

mechanical or spatial skills

accuracy of complex construction, mechanical devices

highly developed navigation

interest in machines and motors

brain function in savants

skills associated more with the right hemisphere

• non-symbolic

• artistic

• concrete

• directly perceived

vs left hemisphere

• sequential

• logical

• symbolic

brain function in savant syndrome

brain damage triggers the release of some dormant capacities

recruitment rewiring, repair that offsets brain damage elsewhere

compensation

testimony to brain plasticity

prodigious memory in savant cases

unconscious, automatic, without reckoning memory

commonly a “habit” rather than a “Semantic” memory

different memory brain circuits

semantic memory brain circuit

cortico-limbic circuit

habit memory circuit

cortico-striatal circuit

training the talent in savants

more effective than trying to “eliminate the deficit”

training does seem to help decrease the deficits in some cases

reinforcement

exceptional skills are typically reinforced and savants may be motivated by the approval

parents and caregivers play a key role in nurturing skills and providing support

BUT only a small number of individuals exposed to strong positive reinforcement show savant skills even in the same facility

extreme male brain hypothesis

suggests a link of autism building on the testosterone hypothesis

recent research does not support this hypothesis for autism

paradoxical functional facilitation

individuals with autism and savants may use less conscious (system 2) processing and substitute unconscious (system 1) processing

conscious system 2 processing

slower

more effortful

make deliberate conscious decisions

unconscious system 1 processing

fast

automatic

make quick decisions and judgements

3 R explanation for savant skills

rewiring

recruitment of capacity from other brain regions → Damage can leave unused brain regions

release of dormant right hemisphere capacity from left hemisphere dominance

genetic memory epigenetics

the biological transfer of knowledge, templates, and certain skills along with the number of other inherited physical characteristics instincts, traits, and behaviors

behavior and the environment can serve to switch on genetic activity without making permanent change to the basic DNA

conspicuous combo

blindness, autistic disorder, and musical genius

sudden genius

not savant syndrome

abrupt emergence of talents in the absence of an injury

no evident “compensatory” deficit

supports the notion of released talent

DSM-5 Criteria for ASD

currently or by history must meet criteria A,B,C, and D

DSM-5 criteria A description

persistent deficits in social communication and interactions across contexts

not accounted for by general developmental delays

manifest by all 3 criteria

DSM-5 A criteria

deficits in social-emotional reciprocity

deficits in non-verbal communicative behaviors used for social interaction

deficits in developing and maintaining relationships

DSM-5 criteria B description

restricted, repetitive patterns of behavior, interests, or activities as

manifested by at least 2 of the criteria

DSM-5 B criteria

stereotyped/repetitive speech, motor movements, or use of objects

excessive adherence to routines, ritualized patterns of verbal/nonverbal behavior, or excessive resistance to change

highly restricted, fixated interests that are abnormal in intensity/focus

hyper- and hypo- reactivity to sensory input or unusual interest in sensory aspects of the environment

DSM-5 criteria C description

symptoms must be present in early childhood (but may not become fully manifested until other social demands exceed limit capacities)

DSM-5 criteria D description

symptoms together limit and impair everyday function

emphasis on the right hemisphere in Autism

autistic individuals tend to show emphasis on right-brain functions similarly with savant skills

• less: logical, abstract, symbolic

• more: intuitive, concrete, visual

acquired dementia

damage to the left hemisphere

damage to the cortico-limbic memory system

reliance on the cortico-striatal memory circuit

Kim Peek

Most likely had FG syndrome- a rare X chromosome-linked genetic syndrome that causes physical anomalies such as hypotonia (low muscle tone) and macrocephaly (abnormally large head)

exceptional memory- able to recall vast amounts of information

instant recall- could easily recite facts and figures from the books he had read

calendar calculations- ability to calculate the day of the week for any given date

Daniel Tammet

Pi memorization

numerical synesthesia: associated numbers with shapes, colors, and textures

fluent in multiple languages

Flo and Kay Lyman

first and only documented monozygotic female twin autistic savants

calendar calculating abilities- have a calendar they see in their head

exceptional factual and autobiographical memory

DA: knocked into music

musicophilia: obsession with playing/listening to music

example of a sudden genius, was neurotypical before the event- acquired savant

fell into a pool and suffered a severe concussion leading to him being hospitalized

the first thing he did when we woke up was go to a piano and was able to play an incredibly complicated classical piece

still can’t read music but can see black squares in his head that tell him how/what to play

still obsessed with music and now a professional musician

TC: struck by music

acquired savant

surgeon stuck by lightning developed an intense passion for music specifically the piano

before the event had minimal interest in playing the piano

after the strike, he formed an intense interest in classical music

he described it like a switch flipping in his brain

there was no cognitive latency or physical problems after being struck

acquired savant

follows a TBI individual develops extraordinary abilities they did not have before

left hemisphere becomes dormant causing the right hemisphere to compensate for both sides

Stephen Wiltshire

prodigious savant, autistic

now a world-famous artist

can retain an exquisitely precise and detailed image in his memory for later recall and drawing

can sense and draw a building, no matter how complex, with a 3D perspective from a 2D photo

Alonzo Clemons

prodigious and acquired savant

talent emerged after suffering a head injury as a child

can look at a picture of an animal and then sculpt a perfect 3D replica in 45-50 minutes