What is autism?
characterized by:
differences in social interactions
communication
the presence of repetitive, stereotyped behaviours
fixated interests
strict adherence to routines
What is the word autism derived from?
auto “self”, -ism “condition”
What is a syndrome related to autism but only present in girls?
Rett Syndrome
What are the social symptoms of autism?
Social Symptoms
infants are ambivalent about being held
arched backs when picked up
may not look or smile
seek someone else for comfort
limited social relationships
avoid or reduce eye contact
What are the language symptoms of autism?
Language Symptoms
language may be altered, delayed, or nonexistent
could include echoing or self-reference in the third person
memorize and repeats words or phrases
talking without understanding others’ interests or misinterpreting their literal speech
What are the self-interest symptoms of autism?
Interests
particular interests & behaviours
stereotyped movements (flapping hands, rocking)
investigates objects (sniffing, textiles, motion)
extreme attachment to an object
precise routines (distress when not followed)
What is the concordance rate for ASD?
70-90% (monozygotic twins)
5-10% (dizygotic twins)
19% likelihood with one older sibling
32% chance with multiple older siblings
What are the causes of autism?
Rubella during pregnancy
Prenatal Thalidomide
Encephalitis from herepes
Tuberous Sclerosis
What brain changes are caused by autism?
10% increase in brain size
1-2% increase in adolescence
Rapid growth f frontal and temporal cortexes only in the first 2 years of life
Striate and Extrastriate cortexes remain unchanged
Amygdala grows unusually and contains fewer neurons in adulthood
The volume of white matter containing short-range axons increased
The volume of white matter containing long-range axons did not increase
Increased volume of the caudate nucleus
Altered development of mirror neuron system
Changes in steroid hormones and neuropeptide signalling
What is the theory of mind?
The ability to predict and explain the behaviour of other humans via their mental states