Autistic Spectrum Disorders

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Autistic Spectrum Disorders

• Theory 1 Testosterone

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Structure

• Systemising
• Empathising
• Digit Ratio
• Waist Hip Ratio
• Evolutionary Psychology

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Human vs. non-human

• Evolved specialised neurocognitive mechanisms
• Discriminate agents vs non-agents
• Animate inanimate (plants)
• Intentional non intentional
• Social non social
• Intuitive psychology to deduce the cause of
  agents actions Empathising
• Intuitive physics to deduce the cause of
  non-agents actions Systemising
• (Dennett, 1987 Premack, 1990)

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Agentive change (Baron-Cohen, 2006)

• If an object change is perceived to be
  self-propelled, the brain interprets the object
  as an agent, with a goal. Such change cannot
  easily be predicted in any other way. To
  interpret agentive change, humans have
  specialised neurocognitive mechanisms,
  collectively referred to as the empathising
  system. The neural circuitry of empathising is
  now quite well mapped. Key brain areas involved
  in empathising include the amygdala, the orbito
  and medial frontal cortex, and the superior
  temporal sulcus.

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Non-agentive change

• Any structured change that is not self-propelled
  is interpreted by the brain as a nonagentive
  change. Structured means non-random, for
  example that there is a precipitating event, or
  some other pattern. The brain doe not deploy the
  empathising mechanisms to predict such change.
  Instead, the human brain engages in
  systemising, that is, it searches for
  structure (patterns, rules, regularities,
  periodicity) in data, to test if the changing
  data are part of a system. Systemising involves
  observation of inputoperationoutput
  relationships, leading to the identification of
  laws to predict that event x will occur with
  probability p.

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Systemising Mechanism (SM)

• Level 1 low
• Leves 2-3 average
• Leve 4 above average systemising
• Level 5 AS
• Level 6 HFA
• Level 7 MFA
• Level 8 LFA

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Autism Spectrum Disorder (ASD)

• Autism and Aspergers Syndrome
• Deficit in empathising
• Preserved or enhanced systemising
• Male bias (41 151)
• Prevalence rates .5 1 lt2
• Highly heritable but not inherited (Beaudet, 2007)

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Triad of difficulties

• Social Communication Imagining
  others minds
• Empathizing

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Triad of strengths

• Islets of obsessions repetitive
• ability with systems behaviour
• Systemizing

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Empathy Definition

• Empathising is the drive to identify another
  person's emotions and thoughts, and to respond to
  these with an appropriate emotion. Empathising
  allows you to predict a person's behaviour, and
  to care about how others feel. (Baron-Cohen, 2002)

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sarcastic
stern
suspicious
dispirited
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grateful
preoccupied
insisting
imploring
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Empathizing
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Systemising Definition

• Systemising is the drive to analyse the variables
  in a system, to derive the underlying rules that
  govern the behaviour of a system. Systemising
  also refers to the drive to construct systems.
  Systemising allows you to predict the behaviour
  of a system, and to control it (Baron-Cohen,
  2002).

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Systemizing
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Examples
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Empathizing
3
3
2
Type B
Systemizing
1
Type E
Type S
0
1
-2
-3
-1
2
3
1
2
-1
-2
-3
Extreme E
Extreme S
-1
-1
-2
-2
-3
-3
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Baron-Cohens continuum

• Scientists as systemisers (especially
  mathematicians)
• Fathers and Grandfathers of children with ASD
  over represented in Science/ Engineering
  (Baron-Cohen et al., 1996/7)

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Billington et al., 2007

• What about students? (n415)
• Physical science degree subjects consisted of
  mathematics, physics, physical natural sciences,
  chemistry, computer science, geology,
  communications, engineering, manufacturing
  engineering, chemical engineering, mineral
  science, material science, astrophysics,
  astronomy, and geophysics.
• Humanities degree subjects consisted of classics,
  languages, drama, education, law, architecture,
  Anglo-Saxon, Norse and Celtic Studies,
  philosophy, oriental studies, English,
  linguistics, theology, history, history and
  philosophy of science, history of art and music.

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Forced-Choice EFT
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males/ females by brain type
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physical/humanities by brain type
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Billington et al.s conclusions

• On average, males obtained higher systemizing
  scores, both relative to their own empathizing
  scores and relative to female systemizing scores.
  Females displayed the opposite cognitive profile.
  
• Despite these sex differences results indicated
  that, regardless of sex, stronger systemizing and
  weaker empathizing was associated with students
  in the physical sciences compared to students
  reading humanities.

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Prenatal testosterone

• Correlates with
• eye contact
• Language
• Social relationships
• Narrow interests

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Digit ratio (Manning, 2002)

• Putative marker for prenatal testosterone/
  oestrogen exposure
• 2D4D ratio
• Relates to maths performance (Brosnan, 2008)
• Children with ASD have long 4th finger
• As do both parents

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Digit ratio (Manning, 2002)

• Putative marker for prenatal testosterone/
  oestrogen exposure
• 2D4D ratio
• Relates to maths performance
• Children with ASD have long 4th finger
• As do both parents

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Systemising and MR (Brosnan and Daggar)

• N126, mean age 30 (sd12)
• Systemising correlates with MR
• Time awake negatively correlates with both MR and
  systemising
• DR negatively correlates with MR but not
  systemising

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In schools(Brosnan, Joiner, Stanton-Fraser)

• The establishment of a dominance hierarchy is
  related to lower empathising capability.
• 92 school children mean age 13.1 (s.d. 1)
• Systemising, Empathising, DR, Prestige (Henrick
  and Gil-White, 2001) work with, play with
• DR(-) Syst () correlate with Prestige

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Pain (Keogh, Munce and Brosnan, 2006)

• Circulating T/ E is argued to moderate sex
  differences in perception of pain
• N50, aged 29 (sd10)
• Relationships with DR inconsistent

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Extremes

• Little relationship in the normal population
• relation to maleness when they occur to extreme
  degrees (Baron-Cohen et al., 2006).

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Broader Phenotype

• Both parents also show a masculinised cognitive
  profile
• High male-typical performance on systemising
  tasks
• High association with Science (esp. Maths,
  physics, computer science) and Engineering
  professions

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Broader Phenotype

• Both parents also show a masculinised cognitive
  profile
• High male-typical performance on systemising
  tasks
• High association with Science (esp. Maths,
  physics, computer science) and Engineering
  professions

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Kanazawa (2005)

• Engineers/ Scientists have more sons
• Nurses have more daughters
• Digit ratio correlates with offspring sex ratio
  (Manning et al., 2002)

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Maternal testosterone

• Maternal dominance (Grant, 2007)
• Mediated by Testosterone
• Increases sex ratio (more boys)
• Mothers of ASD have more androgen-dependent
  disorders (Acne, breast/ uterine/ ovarian
  cancers/ tumours/ growths), Ingudomnukul et al.,
  2007.

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Assortative mating

• High systemisers combine to increase probability
  of ASD
• Prospective case study (Baron-Cohen et al., 2006)
• SEM (Constantino and Todd, 2005) Both parents in
  top quartile leads to an 11 fold increase in
  child pathology

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SM Level 4

• Level 4 corresponds to individuals who systemise
  at a higher level than average. There is some
  evidence that above-average systemisers have more
  autistic traits. Thus, scientists (who by
  definition have the SM set above average) score
  higher than non-scientists on the autism spectrum
  quotient (AQ). Mathematicians score highest of
  all scientists on the AQ. Parents of children
  with ASC also have their SM set higher than
  average and have been described as having the
  broader phenotype of autism. At Level 4 one
  would expect a person to be talented at
  understanding systems with moderate variance or
  lawfulness.

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Family tree (Baron-Cohen, 2008)
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Waist Hip Ratio

• WHR
• Correlates with DR
• Correlates with childs DR
• 0.7 perceived to be most attractive
• (Waist Chest Ratio in men)

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Body Mass Index

• BMI
• Weight (kg) / height (m)2
• (Weight (lb) / height (in)2 ) x 703
• Average 18.524.9

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WHR (Brosnan and Walker)

• 65 control fathers 52 fathers of ASD, both 2.2
  children
• Control fathers preference
• narrow (0.71) gt mid (0.75) gt wide (0.79)
• ASD fathers not the case
• ASD children first-borns
• ASD fathers more older brothers
• ASD higher sex ratio (0.47-0.68 0.65-0.75)

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Kanazawa (2006,2007)

• Violent men have more boys
• Taller parents have more boys
• Attractive parents have more girls

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James (2006)

• Testosterone and Oestrogen levels of mother and
  father affect sex ratio (higher T relates to
  higher sex ratio).
• James/ Manning/ Baron-Cohen/ Kanazawa/ Grant
  theories hang together
• Not significant for ASD (James, 2008)
• Evolutionary psychology

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gTWH (males)

• Parents who possess any heritable trait which
  increases male reproductive success at a greater
  rate (or decreases male reproductive success at a
  smaller rate) than female reproductive success in
  a given environment will have a
  higher-than-expected offspring sex ratio (more
  males).

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gTWH (females)

• Parents who possess any heritable trait which
  increases female reproductive success at a
  greater rate (or decreases female reproductive
  success at a smaller rate) than male reproductive
  success in a given environment will have a
  lower-than-expected offspring sex ratio (more
  females).

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Match.com

• Three basic questions
• 1) Height
• 2) Body type (slender, about average, athletic
  and toned, heavy set, a few extra pounds, stocky)
• 3) Star sign

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Further reading

• Assortative mating
• http//www.edge.org/3rd_culture/baron-cohen05/baro
  n-cohen05_index.html
• The Psychologist (feb 2008)