Neurolinguistics and psycholinguistics study the neurological and psychological bases of language. Localization attempts to locate language in the brain and suggests it is an independent faculty rather than part of general thought. Lateralization shows language functions become specialized in each hemisphere, with split-brain patients demonstrating this. The left hemisphere controls language and is dominant for most individuals. Key brain areas involved in language processing include Broca's and Wernicke's areas in the frontal and temporal lobes of the left hemisphere respectively.

2. How do we study language in
the brain?
0Neurolingiustics:
Neurolinguistics studies the
neurological bases of language . Explores how the
processing involved in language takes place across
nerves . Pays close attention to chemical and electrical
processing in the brain .
0Psycholinguistics:
Psycholinguistics studies the
psychological underpinnings of language . Focuses on
acquisition, storage, comprehension, and production of
language .

3. Localization:
0Attempts to locate language in the brain
having a long history.
0This suggested that language must be an
independent faculty and not part of our
general powers of thought and reasons.
0It states that two parts of the brain are flexible
enough.
0Noam Chomsky derived attention to the fact
that every normal child successfully acquires a
first language , no matter what its intelligence
or learning style is .

4. Lateralization:
0Human body is asymmetrical: heart, liver, use
of limbs, etc.
0Functions of the brain become lateralized.
0Each hemisphere specialized for particular
ways of working.
0Split-brain patients are good examples of
lateralization of language functions.
0In infancy , the relationship between the two
parts of the brain is flexible enough for
language to relocate itself on the right when
necessary.

5. LAD:
0LAD stands for language acquisition device .
0LAD is inborn in a child.
0According to some scientists it ends after the
age of 7 years but many says that it ends after
the age of 12 years.
0Human brain id divided into two parts i.e. left
hemisphere and right hemisphere.
0Left hemisphere controls the right one and
right hemisphere controls the left one.

6. Brain areas involved in
language:

7. Geography of Brain:
Upper vs Lower
Left vs Right
Front vs Back

8. Upper vs Lower Brain :
0Upper Brain:
The upper parts of the brain consists
of `grey matter` known as cortex . It deals with stored
information , analyzing input and controlling
sophisticated muscular movements . Below it is the sub-cortex
of `white matter` which is mainly nerve cell
fibers .
0Lower Brain:
Lower parts of the brain are
responsible for reflexes action , controlling functions
such as breathing and heart beat . The cerebellum at the
base of the brain has a delicate role in coordinating a
range of muscular movements which have become
highly automatic .

9. Left vs Right Brain :
Left and right brain are joined by a complex web of
nerve connections known as the corpus callosum .
0Left Brain:
The left hemisphere controls movement
and sensation on the right side of the body . The left
hemisphere in most individual is associated with
analytic processing and symbolization .
0Right Brain:
The right hemisphere is linked to the
left side of the body . The right hemisphere is associated
with perceptual and spatial representation .

10. Front vs Back Brain:
0 The outer surface of the brain is marked by mounds
and valleys . These serve to mark out four regions in
each hemisphere , known as lobes . These are :
• Frontal lobe ( at the front )
• Temporal lobe ( running from front to back )
• Occipital lobe ( at the back )
• Parietal lobe ( at the back )

12. Language disorders:
0Aphasias are inability to perceive, process, or
produce language due to physical damage to the
brain.
0Broca’s aphasia results in an inability to produce
sequences of sounds in fluent speech; tendency to
eliminate any functional vocabulary.
0Wernicke’s aphasia results in inability to
understand speech and inability to speak
meaningfully.
0Acquired dyslexia and Acquired dysgraphia
due to angular gyrus damage.

13. Comparison between
human and primitive
brains:

14. The cortex is much more extensive in human beings .
Human pre-frontal areas are up to six times bigger than
those of chimpanzees .
The brain of other species are divided into two hemisphere .
Like human beings a number of species have a left
hemisphere which is more developed .
In monkeys , the left hemisphere dominates in the processing
of rapid auditory stimuli .
In human beings , a great proportion of the motor areas is
given over to the control of mouth , tongue and jaw .
The human cerebellum is very much larger , relative to brain
size , than in other species .
The motor areas in human cortex control larynx , which
regulates the passage of air in breathing and speech .
In other species the operation of larynx is controlled by other
parts of the brain .