Neurolinguistic Staudacher

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Representation of multiple

languages in human brain

Staudacher Veronika

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Presented Paper

Kim, Relkin, Lee, Hirsch. (1997) „Distinct cortical areas

associated with native and second languages“.

Nature ,vol. 338: p. 171

 –174.

Research at the Department of Neurology and

Neuroscience, Cornell University Medical College,

New York

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Overview

Methods of investigation

a) Imaging

b) Analysis and subjects (test persons)

c) Task

Results of representation in brain areas of 

a) native language

b) second language (early & late bilinguals)

Summary and Conclusions

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Method of investigation

• fMRI: 1.5-tesla magnetic resonance

scanner, with fixed head position

• 16 slices of brain (4.5 - 4.7 mm )

•

Areas of interest:* the inferior frontal gyrus (=anterior

language region; Broca‘s area incl.

Brodmann‘s 44 +46)

* the superior temporal gyrus

(=posterior language region; Wernicke‘s area incl. Brodmann‘s 22)

• 30 images, one every 3 sec., 10 during

baseline period, 10 during a stimulation or task period, 10

baseline again

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Analysis and Subjects

•

2 identical runs with each language, native and a secondlanguage

• Statistical analyses of changing signals between baseline and

stimulation periods

• 12 healthy multilingual volunteers, 9 male, 3 females

• Right-handed or ambidextrous

• Mean age 29.3 years

•

6 early bilinguals (parents speak one language, kids& friendsanother one, or parents spoke 2 languages)

• 6 late bilinguals (L2 in early adulthood, 11.2 years, lived in

country of L2)

•

Alltogether 10 languages represented, equal fluency

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Task

• Persons were prepared before starting

• Describe events of the previous day (morning,

afternoon, nightsignals were taken)

• Sentences had to be generated silently (internal

speech) to avoid head movement

• Briefing before task in which language the person

should be speaking silently, because• Languages were altered during session to avoid

habituation

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Results

• Focus of observations on Broca‘s and Wernicke‘s 

areas, axial slice

• Typical late bilingual: anterior language

area (Inferior frontal gyrus, Brodmann‘s 44)

green box:red: significant activity during native

language (Engl.)

yellow: activity during second

language (French)

2 centers of activation(+), separated

7.9 mm

Result: 2 separated areas for each language

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Results

• Late bilinguals: distinct areas of activation in Broca‘s 

area (anterior) for different languages

Examples of bilinguals: 

red: significant activity during native language

yellow: activity during second language

2 centers of activation(+)

various distances according to language

combinations

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Results

• Late bilingual: posterior language area (superior temporal

gyrus, Brodmann‘s 22)

green box:

red: significant activity during

native language (Engl.)yellow: activity during second

language (French)

orange: common area for native

and second language

2 centers of activation(+),

separated only 1.1 mm

Result: similar or identical

cortical regions serve

both languages

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Results

• Early bilingual (e.g. English, Turkish): : in posterior

language area (superior temporal gyrus, Brodmann‘s 22)

green box

red: significant activity Turkish language task

yellow: activity English language task

orange: common voxels for both languages

2 centers of activation(+), separated only 2.3 mm,

within

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Results

Result: Late acquisition of L2 = tendency of spatially distinction in Broca‘s area,

little or no separation in Wernicke‘s area (be it early or late acquisition) 

Late bilinguals Early bilinguals

Broca‘s Area:

Mean distance of 

center-of-mass

6.43 mm 1.53 mm

Number of voxels Equal for each

language,separated

multiple common

voxels

Wernicke‘s area:

Mean distance of 

center-of-mass

1.95 mm 1.58 mm

Number of voxels Different for each language

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Conclusions

• Age of language acquisiton may be a significant factor for the

functional organization in brain.

• Children can discriminate all phonetical differences at the

beginning of their life, but then may adapt the acoustic space

in brain to their native languages.

• Adjacent cortical areas are used for second language learning

as an adult.

• The younger a child, when learning a second language, the

less distinction in brain (PET study: average age 7.9 years).

• Further questions rise concerning Broca‘s role in processing

the phonetic structure of different languages.

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Thank you!