The document discusses several key points about lateralization of brain function: - The brain is divided into two hemispheres, the left and right, which each specialize in different functions. The left hemisphere typically controls language and logical thinking while the right controls visual-spatial skills and emotions. - Lateralization refers to this functional specialization of the two hemispheres, with some neural processes localized to one side or the other. The two hemispheres are connected by the corpus callosum.

2. •Lateralization is the idea that the two halves
of the brain are functionally different and
that each hemisphere has functional
specializations, e.g. the left is dominant for language,
and the right excels at visual motor tasks.
• In other words:
The lateralization of brain function is the tendency for
some neural functions or cognitive processes to be
specialized to one side of the brain or the other. The
medial longitudinal fissure separates the human brain
into two distinct cerebral hemispheres, connected by the
corpus calosum.

3.  The brain is divided into two hemisphere i.e.
left hemisphere and right hemisphere.
 Each hemisphere is responsible for specific
functions.
 Lateralisation: The dominance of one
hemisphere of the brain for particular
physical and psychological functions.

4.  Lateralization – each hemisphere has abilities
not share with its partner
 Cerebral dominance – designates the
hemisphere dominant for language
 Left hemisphere – controls language, math
and logic
 Right hemisphere – controls visual-special
skills, emotions and artistic skills

5.  The dominant language is the language with which
a bilingual or multilingual speaker has greatest
proficiency and/or uses more often.
 Language dominance is, on its face, a relatively
simple concept. It refers to the degree of
bilingualism manifested by individuals who know
two languages, that is, the relative level of
proficiency in each of the languages. A person may
know both equally well, in which case we speak of
balanced bilingualism.
 It refers to the degree of bilingualism , those who
know two languages.

6.  It includes three situations:
1. A person who knows both languages equally.
2. A person can exhibit greater control of one over
other.
3. In this case we consider first language to be
dominant over the other.

7.  Dominant Bilingual: someone with greater
proficiency in one of his or her languages and
uses it significantly more then the other
languages. Means A person who is a native
speaker in one and is capable of
understanding but not speaking another
language.
 Balanced Bilingual: Someone whose mastery
of two languages is roughly equivalent.
Means a person being more proficient in one
of the two languages .

8. Modularity of mind is the notion that a
mind may, at least in part, be composed
of innate neural structures or modules
which have distinct established
evolutionarily developed functions.
 Selective loss of a specific cognitive
function via brain damage is support for
the modularity view

9.  But the modularity does not
necessarily predict that there should
be specific brain areas dedicated to
specific cognitive functions.
So modularity could be true even if
there was no selective language
impairment via brain damage.
 the ways brains are determined by
genes and so selective lss or sparing
of language genes should lead to
selective loss or sparing of language.

10.  The critical period hypothesis states that an
individual must acquire a language by a
critical period otherwise it will be difficult to
acquire a language.
 It states that the first few years of life is the
crucial time in which an individual can acquire
a native language (L1) if presented with
adequate stimuli.

11.  It also states that there is only a small
window of time for a first language to be
natively acquired.
 If a child is denied language, she will not
acquire the language.
 So an adult learning a language is almost
never as component as native speaker.