5. ASSUMPTIONS
It might be that left-handers die
younger
A left-handed academic from North
Dakota has revealed that lefthanders tend to die younger than
right-handers : 65 (left-handed), 68
(right-handed), 70 (ambidextrous)
6. ASSUMPTIONS
There is a higher proportion of natural lefthandedness for males than females and this
seems to occur everywhere in the world.
Between 10-12% of people on earth are
“lefties.” Women are more likely to be righthanded than men by about 4 percentage
7. ASSUMPTIONS
The effect of sexual hormones released in
the brain during the development of the
foetus may be the cause of this phenomenon.
At various times in history, left-handedness
has been seen as many things: a nasty
habit, a mark of the devil, a sign of
neurosis,
rebellion,
criminality,
and
homosexuality. It has also been seen as a
trait indicating creativity and musical
abilities.
8. ASSUMPTIONS
Tests conducted by St. Lawrence University in
New York found that there were more lefthanded people with IQs over 140 than righthanded
people.
Famous
left-handed
intellectuals include Albert Einstein, Isaac
Newton, Charles Darwin, and Benjamin
Franklin
9. ASSUMPTIONS
According to the Journal of Nervous and
Mental Disease, the brains of left-handers
process emotions differently than those of
right-handers and are more susceptible to
negative emotions, such as anger.
Size is not the crucial factor which would
explain human language and non-human lack
of language.
10. External structure of the brain
Parietal lobe
Frontal lobe
Occipital lobe
Temporal lobe
Cerebellum
Brain stem
Functions of the lobes
Link to 3D image of brain
Spinal cord
11. Internal structure of the brain
corpus collosum
cerebral cortex
thalamus
ventricle
hypothalamus
cerebellum
pituitary gland
pons
midbrain
medulla oblongata
12. cerebral cortex
Sensory information such as
vision, smell and hearing
processed here. Higher cognitive
functions.
corpus callosum
Connects the left and
right hemispheres to
coordinate information
hypothalamus
Homeostasis:
control of body
temperature and
osmoregulation.
Secretes hormones
pituitary gland
Produces hormones that
control growth, sexual
development and
metabolism
midbrain
Involved in control of visual and
auditory systems. Also controls
body movement
cerebellum
Fine motor
control, posture
and balance
pons
Links the
medulla with the
thalamus
medulla oblongata
Controls breathing, heart rate
and blood pressure; reflex
actions such as vomiting and
sneezing
16. LATERALIZATION
The separation of structure and function in the hemispheres
is technically referred as lateralization
Two halves of the human brain are not alike.
Right-handed persons with lateralization for language in the
left hemisphere will perceive more readily speech sounds
through the right ear than the left.
“Ba” left ear, and “da” on the right ear
Da passes directly to the language processing centres in the
left hemisphere while ba has to travel a longer route
Music and non-linguistic sounds, noises and animal sounds
are perceived more strongly in the left ear since they are
processed in the right (non-language) hemisphere.
18. LANGUAGE AREAS AND FUNCTIONING
These two areas are connected by the
arcuate fasciculus.
When hearing a word: the sound of the
word goes from the ear to the auditory
area of the temporal lobe and then to
Wernicke‟s area.
If a heard word is then repeated
aloud, the sound must pass to the
Broca‟s area
20. NEURAL PATHWAYS INVOLVED IN THE
PROCESSING OF SPOKEN LANGUAGE
Speech Production: generated in the Wernicke‟s area
and sent it to Broca‟s area
Reading aloud: the written form is first received by the
visual co text then transmitted to the Wernicke‟s area
where it is associated with the auditory represenattion
and then sent to the Broca`s area
• Speech Comprehension: The signal arrive in the
auditory cortex from the ear and are transferred to
Wernicke‟s area, where they are interpreted.
21. IS IT LEFT HEMISPHERE THE ONLY ONE IN
CHARGE OF LANGUAGE LEARNING?
Although most languages processes occur in Broca‟s
area, Wernicke‟s area and angular gyrus, some
language functioning does occur elsewhere in the
left hemisphere, and some even occurs in the right
„non-language‟ hemisphere. (Penfield y Roberts)
The ability to attach and understand intonation, such
as the rising tone of a question, the ability to
interpret emotional intentions, such as anger or
sarcasm from inflections in the voice, and the ability
to appreciate social meanings from something such
as wispering, may very well be, located outside of
what we have traditionally regarded as the main
language areas of the brain.
22. BRAIN MATURATION AND CRITICAL AGE FOR
LEARNING LANGUAGE
An age beyond which language learning will
be difficult or even impossible.
There is evidence that damage to language
areas in the left hemisphere of very young
children are compensated for, with the right
hemisphere taking over the reacquisition of
language functions.
Language then becomes located in the right
hemisphere for these individuals. (This
sometimes happens with adults )
23. BRAIN MATURATION AND CRITICAL AGE FOR
LEARNING LANGUAGE
Lennenberg, who based in his work with
aphasic children, set puberty as the age
or time in a child‟s life beyond which this
kind of recovery would not longer occur.
Krashen, found that the age limit of
recovery (the right hemisphere taking
over damaged left hemisphere functions)
is much lower approximately age 5 years.
24. BRAIN MATURATION AND CRITICAL AGE FOR
LEARNING LANGUAGE
The age limit of potential language learning
in an undamaged left hemisphere might well
be beyond the 5-year limit proposed by
Krashen on the basis of damaged brains.
With regard to a critical age for secondlanguage learning, until 12 years of age and
after that age (native-speaker pronunciation)
Since other aspects of second language
learning do not decline with age.