Language&The Brain

7/31/2019 Language&The Brain

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LANGUAGE

&THE BRAIN


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Why do we have preferences????

Which foot did you use?

Which hand did you use?

Which side of your head did you turn?

NOW!

Imagine you do those activities with opposite

side of your preference!

So, the answer lies in the brain, its

structure and function.


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The Hemispheres of the Brain

Frontal lobes

Median longitudinalfissure

Central sulcus (fissure ofRolando)

Pariental lobes

Occipital lobes

The over head view

LEFT CEREBRALHEMISPHERE

RIGHT CEREBRALHEMISPHERE


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The side view


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Size and the Weight of the Brain

The brain of average human adult

1-1,5Kg.

The size of the brain does not relate tothe intelligent of people.

Adult brain weight approximatelythree times the weight of his brain at

birth.


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The Central Nervous System of Cerebral Cortex

Four major parts of the brain;

1. The Medulla Oblongata (sumsum sambung) concerned

2. The pons varolii (Jembatan Varol) physical

3. Cerebellum (Otak Kecil) body

4. Cerebral Cortex / Cerebrum (Otak besar) function

The Brain &Spinal Cord

The central nervoussystem


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The medulla oblongata, thepons varolii, and the

cerebellum

PhysicalBodily

Function

Breathing, heartbeat, transmission andcoordination of movement, involuntary

reflexes, digestion, and emotional

arousal

The Cerebral Cortex

Advance intelectual

functioning and language

Thinking, reasoning, learning,memory, intelligence, senseof responsibility, perceptionof the senses, initiation andcontrol of voluntary musclecontraction


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The Brain

pons varolii

medulla oblongata

cerebellum

spinal cord

cerebral cortex

cerebrum

Acknowledgement: Picture of model from Mentone Educational Centre C15


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HEMISPHERIC STRUCTURE AND

FUNCTION


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Left and right hemispheres control

opposite sides of the body.e.g:

Stroke is the sudden death of brain cells

due to lack of oxygen, caused byblockage of blood flow or rupture of anartery to the brain.

A stroke in the right hemisphere of braincan affect victims on the left side of thebody and the opposite.


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Vision

A stroke in one side of the brain will not

automatically cause useless the eye andear on the opposite side of the body.

The person will still be able to see a

whole image from only the right eye,since both the left and the righthemisphere will be involved.

The divided fields of vision allow fordirect sensory input to both hemisphereseven with only one functioning eye.


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Audition

Certain types of sounds tend to be processedin one hemisphere while other types tend to

be processed in the other hemisphere.

The hemisphere closest to the damaged ear

will still be able to receive sound, since theundamaged ear will send sounds signalsinternally to its opposite hemisphere.

Having only one functioning ear still enables

hemisphere to access the sound. It becausethe other good ear can extend sounds to bothhemisphere.


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Hemispheric Dominance

The Left Hemisphere Dominates theRight

Dominance is where the onehemisphere is controlling the one.

Hand and Foot Preference

A left hemisphere dominant person wouldtend to use the right hand and the right foot

and the opposites.

The majority of people prefer their righthand and foot. It indicates that the left

hemisphere dominates the right.


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Left- Handers

The lack of strong dominance for left-

handers is believed to be a factorcontributing to speech disorders and tovarious reading and writing dysfunction(stuttering and dyslexia).

Lamm and Epstein (1999), report that left-handers native Hebrew speakers perform lesswell than right-handers in the study of English,

Especially reading. It seems to be caused by thetwo hemispheres vying with one another fordominance and Salive, Guralnik, and Glynn,(1993) argue that left- hander dies younger.


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A gene for handedness

The researcher who has studiedhandedness and believe there is a specificgenes for it is Amar Klar.

He convinced that there was a single gene

that makes us right handed. When thegene was defective, we have a 50%chance of being right handed and 50%chance of being left handed or

ambidextrous.


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Left-handers:Achievement and discrimination

Interestingly, among left-handers there isa greater proportion, artists, musiciansand writers that is found among right-handers. In the 20th century USpresidents are left-handers such asTruman, Reagan, Bush, and Clinton.

The greatest thinker of all time, AlbertEinstein. He is a left handed too.


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Sound Preferences

The two hemispheres specialize inprocessing these two types of sounds(speech and non-speech).

For the true right hander, speechsounds are mainly processed in the lefthemisphere while music, animal soundand noises are mainly processed in theright hemisphere. The opposite will bethe case for some left hander.


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Listening behind a closed door

If you are right hander right earforward.

This is because :

Speech sounds are processed inthe left hemisphere.

The first big impulse of speechsound will be transmitted to the left

hemisphere to the right ear The first big impulse will precede

and dominate any other bigimpulse.


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Lateralized Hemispheric Function

Lateralization is the separation offunction of brain hemispheres


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Left-Hemisphere Specialization

Left-hemisphere is concerned withlogical and analytical operations andhigher mathematics.

The main language centres are BrocasArea, in front part of the brain,Wernickes Area, Towards the back,and the Angular Gyrus, which is even

further back.


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Right-Hemisphere Specializations

The right hemisphere is involved inrecognizing emotions, recognizingfaces, and perceiving the structuresof things globally without analysis.

It also deals with music and nonlinguistic sounds, such us noises andanimal sounds.


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Sex Differences and Lateralization

It may be that females have a thickerleft hemisphere while the males have athicker right hemisphere.

Language ability typically are locatedin the left hemisphere and visual-spatial are located in the righthemisphere.


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Split Brain Effects

The certain aspects of lateralizationhave been confirmed by the work of

Sperry (1982) separated the twohemispheres of the brain by severingthe connecting tissue, the corpus

callosum, of a number of patients.


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It was found that the split-brain personcould still use speech and writing in thedisconnected left hemisphere but thattheir right hemisphere had little such

capacity. In normal persons, the righthemisphere has some capability.


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Language Areas and their

Functions

Brocas Area, The Motor area, andSpeech Production

The speech production process wouldbegin in Brocas Area, pass on throughthe arcuate fasciculus to the motor area

and from there to the articulators ofspeech for vocalization.


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Wernickes Area, the auditory area,

ans speech understanding

Speech comprehension

It is located in the upper part oftemporal lobe, extending upwards intothe partial lobe, plays a major part inthe speech comprehension.

Wernickes area, must in some way be

connected to the auditory area.


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Speech Production

The basic structure of the utterance is thought to be

generated in Wernickes area and is sent to Brocas

area for encoding, and then passed on to adjacent

motor area, which governs the articulatory organs.

Reading aloudThe written form is received by visual cortext, then

trasmitted via angular gyrus to Wernickes area, where

it is ought to be assosiated with the auditory

representation, then the utterance structure is then

sent on to Brocas area.


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Right-Hemisphere LanguageAbilities


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Typical Language Function

Recent evidence indicates that the righthemisphere is involved in languageprocessing as well.

Left+Right hemispheres receive similiar

input and both attempt to process for everylanguage process.

The hemispheres compute informationdifferently at each level of processing (e.g.

Semantic processing), so that eachhemisphere is most adept at handlingparticular inputs and producing particularoutputs (Chiarello & Beeman, 1998, p. X)


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Word semantic

(Faust, 1998)

The right hemisphere has been found to

be more adept at processing single lexicalitem and the semantic relation between them.

While it is the left hemisphere that combine

syntactic, semantic, and pragmatic information

into a conceptual representation of a

sentence.


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Understanding Discourse and other minds

The RH is critical for understandingdiscourse. (Beeman,1993)

E.g:

Patients who have damage in their RH showstructuring problems in story recall (Moya etal 1986), and their speech disrupted,particularly in the level of discourse,jumping from one topic to anotherincoherently. (Brownell&Martino1998) Theyexperience difficulty in making inference as

well.


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Metaphor

The coarse semantic coding of the RHmay also relate to the ability of thishemisphere to understand metaphore(Brownell, 1988)

E.g: The king of the Jungle went to the

palace.


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The Right Hemisphere Can Take

Over Left-Hemisphere Functions.

There is growing evidence that damageto language areas in the left hemisphere

of young childern is compensated for,with the right hemisphere taking over thereacquisition of language.

This sometimes happens with adults, aswell.


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See, the example p. 326-327

Smith & Sugar (1975) report a boy aged 5

years and 6 months who had a left

hemispherectomy (the removal of the entire

LH, which includes the main language

areas). When tested 21 years later, heshowed normal language and intellectual

capacities.

The RH and other intact residual structuresmust therefore have compensated for the

loss of the hemisphere.


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So,,,

The right hemisphere is often capable oftaking over typical left hemisphere

functions, even after the entire lefthemisphere has been removed.


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The Bilingual Brain


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Is there Hemisperic Specialization forLanguages?

Does the Age at which a SecondLanguage is Learned Related to

Lateralization?

Consider these questions!


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Is there Hemisperic Specializationfor Languages?


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Albert and Obler (1978) argue that theright hemisphere plays a major role in thelearning of a second language even inadulthood.

Their position is based partly on the findingthat apashia (language dysfunction) is

more likely to be found following right-hemisphere leions in bilinguals (10%) thanin monolinguals (1-2%).

Study showing right-hemisphere

involvement


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If the right hemisphere is damaged, andapashia results, then they argue that the

location of second language must be inthe right hemisphere.

Cont...


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A number of studies, on the otherhand, have reported no different in lateraldominance for the first and the secondlanguage.

Soares (1982, 1984), Walters andZatorre (1978), and Zatorre (1989) foundno different between monolinguals andbilinguals.

Studies Finding No Different


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Galloway and Scarcella (1982), in aSpanish-English dichotic listening study,

found no evidence for the righthemisphere being involved more in theinitial stages of informal, adult, second-

language acquisition.

Cont...

S


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While finding are not consistent, the fact thatthe right-hemisphere difficulties are involved

in so many studies suggests the distinct

possibility that a second language sometimes

locates in the right-hemisphere and sometimes

not. There may be variables which determine

hemispheric location but which have not been

identified yet.

So...


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Does the Age of at which a Second

Language is Learned Related toLateralization?


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Genesee, Hamers, Lambert, Mononen,

Seitz, and Stark (1978) found that the age at

which a second language is learned affectedlateral dominance.

E.g:

1. Those who became bilingual from infancy.

2. Those who became bilingual from around

4 to 6 years of age.

3. Those who became bilingual from

adolescence.


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Sussman, Franklin, and Simon (1982)

showed that early bilinguals (acquired prior

age 6) showed that LH dominance for bothlanguages, while late bilinguals (acquired

after age 6) revealed LH dominance only

for the first language and symmetricalhemisphere involvement for the second

language.


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Wulleim (1994) reported greater RH

involvement for older learners of both

English and Tok Pidgin than for younger

learners. Older learners were those who

acquired the languages after the age of 8

years.


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However, Vaid (1987) reports the opposite

for French-English bilinguals, the LH was

more affected in late bilinguals (acquired

second language between age of 10 and 14)

than in early bilinguals (acquired second

language before age of 4)


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Gordon and Zattore (1981) found no

difference in hemisphere dominance

between two groups of English-Spanish

bilinguals, with one group having acquired

the second language around the age of 9 and

another having acquired it around the age of

13.


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Klein, Zattore, Milner, Meyer and Evans

(1994) have reported similar findings. Theyused PET (Positron Emission Tomography)

to compare cerebral blood flow when

English-French bilinguals repeated words inthe first (English) or in the second language

(French), with the second language being

learned after the age of 5 years. There wasrelatively little difference, with the two

languages activating similar brain areas.

S


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The distribution of speech areas in the brain

appears to be related to a variety of factors,

including, for example, what task bilinguals

are given (comprehension vs. production),

when a second language is acquired, and

what method of analysis is used.

So,


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Sign Language


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Hemisphere location of Sign Language

Comparisons of Sentence Processingbetween Signers and Non-Signers

We will study about these;


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Left-Hemisphere Damage Affects Signing

Right-handed deaf signers, exhibit apashia

when critical LH areas are damaged

(Poizner, Klima, & Bellugi 1989).

Hemispheric Location of Sign

Language

Tachistoscopic Studies Inconclusive


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Tachistoscopic Studies Inconclusive

Most of the research involved in determiningthe hemispheric location of sign language is

based largely upon tachistoscopic visual half-

field studied, where what enters the right and the

left field of each eye is controlled by a devicecalled a tachistoscope, which projects images.

As a whole, these studies yield inconsistent

and contradictory findings, ranging from reportsof right hemisphere dominance, left-hemisphere

dominance, to no hemispheric asymmetries for

sign-language processing in the deaf.

C t


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Poizner, Battison, and Lane (1979)

compared the contribution of movement in

sign-language stimuli. They reported a leftvisual field (LVF) advantage for static signs

and no hemispheric asymmetry for moving

signs.

Cont...

Cont


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Grossi, Semenza, Corazza and Volterra

(1996) reported no hemisphere asymmetryfor judgements of signs based o psysical

characteristics.

However, a significant right visual field

(RVF) advantage emerged when subjects

were asked to make judgements ofhandshapes that were matched in shape to

one another.

Cont...

Comparisons of Sentence


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A fMRI study by Neville, Bavelier, Corina,

Rauschecker, Karni, Lalwani, Braun, Clark,Jezzard and Turner (1998) shows that when

hearing or deaf subjects process their native

languages (ASL or English), anterior andposterior languages areas within the left

hemisphere are used.

Comparisons of Sentence

Processing between Signers and Non

Signers

C t


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Other electrophysiological (EEG, etc)studies of neurologically intact native

signers also indicate that both the left and

right hemisphere are active during ASLsentence processing (Neville, Coffey,

Lawson, Fischer, Emmorey, and Bellugy,

1997).

Cont...


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The left hemisphere appears to be centrally

involved in sign language, as it is with non-

signers. The right hemisphere also isintricately involved but in ways different

from that of non-signers.

In conclusion...


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Language Disorders

Aphasias


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Aphasias

Damage of specific site in the hemispherewhere language is located

The damage influences :a. Speech

b. Reading

c. Writing


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1. Brocas Aphasia

it caused by war injuries, strokes, caraccidents

The damage is only to certain portionof brain

It influences speech and writing

Meaningful but shortened speech eg:ungrammatically correct

Which one is easier?

The book that the irl is takin is blue


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Syntactic relation

Is the cause

Same word utter in conversation could be

more difficult than when they use itwhile they are singing.

Example???


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2. Wernickes Aphasia

Non-sense speech = Double talk

Sounds right, grammatically correct

BUT meaningless Example ???

Beside that, it also includes similar

sound (Chair-Shair), word loss (it isa.)


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Other Speech Related Aphasias

1. Pure word deafness cannot recognizethe sounds of words as speech but canhear other types of sounds (ex:song).

2. Conduction aphasia poor ability torepeat words.

Example : bubble bupple, noun verb,

64928 John is sleeping

3. Anomic Aphasia Problems in findingthe proper words.

Exam le : Geor e men ambil ba u utih


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4. Apraxia unable to respond verbalcommand

5. Global Aphasia many or all aspect oflanguage are severely affected especiallyin the left hemisphere (language areas) ex

: stroke

Determining type of Aphasia

a. Was the tissue completely destroyed or

damage slight?

b. Did the damage occur suddenly orovertime?


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Dyslexias (Reading and Writing)

Some children only able to writebackwards (reed-deer), confuse letters

(b-d, p-q) So, better if we give words in context ,

not in isolation

Types :a. Alexia reading (ex: cannot read

what they have written)

b. Agraphia writing (ex: they can say


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Japanese writing aphasias

It displays quite unusual characteristicsdue to the nature of their complex

writing system Syllabic kana

Morpheme kanji

Some patients cannot read kana butthey can read kanji.

R l ti ifi t f


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Relating specific aspects of

language toCertain localized

areas of thebrain

LOCALISM

Global areas of

the brain

HOLISM


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Effects

Attention span

Motivation

Start to do something but suddenlycancel it

Want to say something but suddenly

forget itBesides that

People who have language disorder

DOESNT MEAN the have lan ua e

Sign-Language Aphasia


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Sign-Language Aphasia

Left hemisphere language area signand signing system

1. Brocas aphasia with signers

Example : native of signer American SignLanguage got stroke to the lefthemisphere will accurate in making asingle sign of language which simple

uninflected meaning BUT they unable toproduce correct movement

2. Wernickes aphasia with signers

produces meaningless individual words

M th d f I ti ti B i


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Methods of Investigating Brain

and Language

1. Traditional

a. Post-Mortemused by Broca, examine

the patients who had displayedlanguage disorders

b. Brain-Operation, accident or tumour

cause removal of a lobe of the brainand entire hemisphere

c. Electrical stimulation, patients who are

conscious during brain surgery.


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2. High-Tech Methods (observe the actualfunctioning of the brain in real time,

without surgery)

a. The CAT (Computerized AxialTomography) scan. X-ray to construct

three dimensional image of the wholebrain or a portion of it

b. The PET (Positron Emission

Tomography) scan. Injecting a mildlyradioactive substance into the blood anddetectors surround the persons head.

When blood flow increases, the brain


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c. Magnetic and Functional MagneticResonance Imaging (MRI, fMRI). Measure

brain function by taking advantage of theincreased local blood flow in areas of thebrain that are active. When the brain

performs a specific cognitive task, there isan increase in blood flow and the cellularactivity associated with that task.

d. Event-Related Potentials (ERPs) =evoked potentials. Measure voltagechanges in the brains by

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Language&The Brain