The Neuropsychology of HCI

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The Neuropsychology of HCI

• Systemising, empathising and digit ratio

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History

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

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History 2

• Theory of mind
• Folk Psychology and Folk Physics
• Systemising and Empathising

4
Systemising

• An intuitive everyday understanding of how things
  work The understanding of properties of physical
  objects, including their causal impact on other
  objects.

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Empathising

• An intuitive everyday understanding of how people
  work The understanding of how actions are caused
  by mental/ intentional states of others.

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Systemising and empathising

• Naturally developing forms of knowledge
• Not explicitly taught
• Acquired universally

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Sex differences

• Males tend to be systemisers
• Females tend to be empathisers
• Individuals with autistic qualities have extreme
  systemising skills but poor empathising skills
• Extreme male brain theory (mostly males)

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• Baron-Cohen (2002 72) argues that all the
  sciences utilize systemizing as their basis, and
  all are dominated by men.
• Professoriate (2.5 are female in the UK)
• Fellowship of the Royal Society (3.6 are
  female).
• Life Science/ Social Science bias (Brosnan,
  1998).

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Continuum

• Male Domination
• Extreme male brain Autism
• Asperger Syndrome
• Science/ Maths
• Social Sciences
• Caring Professions
• Extreme female brain
• Female domination

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The brain!
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Localization

• Occipital lobes vision
• Parietal lobes spatial
• Temporal lobes memory/language
• Frontal lobes - Abstract thought, organise
  behaviour, inhibition Executive functions

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Contralateral
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Basic neuropsychology

• TASK LEFT HEMISPERE RIGHT HEMISPHERE
• __________________________________________________
  ____________________________
• Vision Translation of letters into
  sounds Recognition of faces
• Hearing Language sounds Non-language sounds
  music
• Memory Verbal memory Visual memory
• Language Grammar Humour, emotional content
• Mathematics Arithmetic Geometry
• Problem solving Problems to be solved
  analytically Problems to be solved
  holistically
• Complex tasks Performed one part at a
  time Performed all parts at a time
• __________________________________________________
  _____________________________

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Lateralised brains

• Cognition has been argued to be lateralised, with
  the left hemisphere dominating for language
  processing and the right hemisphere dominating
  for spatial/ mathematical processing (Bryden,
  1982).
• A sex difference is often reported, indicating a
  tendency in females to be left hemisphere biased
  and a tendency in males to be right hemisphere
  biased (Wisniewski, 1998).

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Maths as an example

• A right hemisphere advantage has been
  demonstrated for abstract numerical relations and
  a left hemisphere advantage for more discrete
  numerical information (Fink, et al., 2006).
• The left hemisphere has been argued to have a
  bias for retrieving arithmetic facts, which may
  reflect the language-based methodology used
  within schools to teach arithmetic rather than
  any inherent bias of these areas for
  number-related information (Geary, 1995).

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Hormones

• Have an organisational and an activational effect
  (Goy and McEwen, 1980).
• Prenatal gonadal hormones (sex steroids) exert
  long-lasting organizational influences on brain
  and behaviour in humans (Collaer and Hines, 1995)
  
• Prenatal organisational
• Circulating activational
• Perinatal around time of birth

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Testosterone and lateralisation

• Higher levels of prenatal testosterone exposure
  may be associated with a greater degree of
  cerebral lateralisation for cognitive functions
  (Hines and Shipley, 1984).

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Hypothesis

• Prenatal testosterone influences brain structure,
  which influences cognition, which influences
  participation within Science.
• But how can you measure prenatal testosterone?

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Digit ratio
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• Index finger (2D) / ring finger (4D)
• Male average 0.98
• Female average 1.0
• Males typically have longer 4D fingers than 2D
  fingers (more testosterone and therefore lower
  digit ratios) than females, who tend to be equal
  (Manning, 2002).

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Preliminary investigations

• The hypothesis is that, for the reasons outlined
  above, success within the computer culture will
  be predicted (at least in part) by exposure to
  prenatal testosterone. Two preliminary
  investigations examine this possibility, relating
  digit ratio with JAVA programming ability and
  computer anxiety.

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Study 1 JAVA programming

• 23 Masters students (18 males)
• Both sexes had a mean digit ratio of 0.98 and
  there were no significant differences in JAVA
  marks between males and females.
• The correlation between digit ratio and JAVA mark
  was significant, however r -0.56, p0.003.

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Study 2 JAVA programming

• Sample 73 Students undertaking a JAVA
  programming course.
• 60 males and 13 females. Aged 18-41, mean20.6
  (sd5.2)
• There were no sex differences in performance,
  males 66 (sd18), females67 (sd23)
  (t710.21, ns) or digit ratio (males 0.98
  (sd0.04), females 0.99 (sd0.04) (t710.72,ns).
  
• r -0.2, plt0.05. A smaller digit ratio,
  indicative of greater exposure to prenatal
  testosterone significantly related to a higher
  JAVA score.

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Study 3 Computer anxiety

• 161 undergraduate students (71 males)
• Again both sexes had a mean digit ratio of 0.98.
• There was a significant difference in computer
  anxiety, with females registering as more anxious
  than males (t2.55, p0.012).
• For males, there was a significant positive
  correlation (r.24, p.02) and for females there
  was a significant negative correlation
  (r-.22, p0.019).

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Maths again

• Maths ability negatively correlates with digit
  ratio (Fink et al., 2006)
• Reflected in 7 year olds SATs results (Brosnan,
  2007)

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Here comes the but

• The effects are small
• Scientists do not all have low digit ratios
  (Brosnan, 2006)
• Digit ratio does not correlate with systemising
  and empathising (Voracek and Dressler, 2006)
• What about circulating hormones?