Handedness

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Biopsychology Thought for the Day I am
returning this otherwise good paper to you
because someone has printed gibberish all over it
and put your name at the top. An English
Professor, Ohio University A fool's brain
digests philosophy into folly, science into
superstition, and art into pedantry. Hence
University education. George Bernard Shaw (1856
- 1950) University politics are vicious
precisely because the stakes are so small. Henry
Kissinger (1923 - ) What we become depends on
what we read after all of the professors have
finished with us. The greatest university of all
is a collection of books. Thomas Carlyle (1795 -
1881) Everywhere I go I'm asked if I think the
university stifles writers. My opinion is that
they don't stifle enough of them. There's many a
best-seller that could have been prevented by a
good teacher. Flannery O'Connor (1925 - 1964)
If we value the pursuit of knowledge, we must
be free to follow wherever that search may lead
us. The free mind is not a barking dog, to be
tethered on a ten-foot chain. Adlai E. Stevenson
Jr. (1900 - 1965)
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Exam for people not here in February (non
graduating visiting students only Monday Dec
12 noon -1 p.m.. WGB F-31.
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Lecture 10 Handedness (Plus!) 1. A
right-handed world 2. Hands and the
hemispheres 3. Lefties Brain-damaged devil
worshippers? 4. Feet, eyes and breasts??
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Hand performance - how do the hands differ on
various tasks? (usually normally distributed)
Hand preference - patterns in how one hand is
preferred over the other (usually a J-shaped
distribution)
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finger tapping dom faster than nondom 5
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right left hand skill (gtbetter right)
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(A typical hand preference inventory...) Show me
how you would 1. Eat soup with a
spoon L R 2. Brush your teeth L R 3. Throw a
ball L R 4. Thread a needle L R 5. Cut a
loaf of bread L R 6. Comb your hair L R 7.
Swing a racket L R -------
/7
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always left always right
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• Right-hand preference
• about 90 in most Western cultures
• slightly higher in Oriental cultures
• Nevertheless historical trends and cultures
  without anti-sinistral biases also suggest
  about 90
• Homo habilis was right-handed?

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The pathological leftie? i.e. Stanley Coren
(1994). The Left-hander Syndrome 1. Die
younger?


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Bland, M., Altman, D. (2005). Do the
left-handed die young? Significance, 2, 166-170.
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The pathological leftie? (Contd) 2. Increased
incidence of left handedness in people with
learning disabilities, epilepsy, Downs syndrome
etc.
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The pathological leftie? (Contd) 3. Higher
incidence in twins 20 versus 10 in the
rest of the population
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The pathological leftie? (Contd) 4. Higher
incidence in men 12 versus 9 in women
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Speech and the hemispheres Sodium amytal --
the Wada test Left hem Bilateral Right
hem Dextrals 95 0
5 Adextrals 70 15 15
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But Adextrals are represented MORE than the
10 that you would expect in. Professional
athletes Artists Architects Are some
adextrals spatially gifted?
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http//www.newscientist.com/article.ns?iddn1501
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Other asymmetries
Footedness - 75-80 right
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Professional Football Players-where are the
two-footers?
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• Other asymmetries
• Eyedness -65-75 right
• Asymmetries in sizes of the two hemispheres?
• Legs?
• Breasts?
• Goolies?

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Next lecture Lecture 11 Summing up