DCL Task 6. Impact of age and experience on language learning
Learning goals
1. Effect of age on language development; organization of neural systems
2. Differences between ASL and normal language speakers in brain activation
3. Effect of age on acquisition and proficiency of bilingualism
1. Effect of age on language development; organization of neural systems
Kim
There might be spatially separate representations for each language. Participants performed
silent, internally expressive linguistic tasks in two languages by subjects who either acquired
conversational fluency in their second languages as young adults (‘late’ bilinguals) or who
acquired two languages simultaneously early in their development (‘early’ bilinguals).
Broca’s and Wernicke’s areas are known to perform central roles in human language
functions.
The main findings for a typical ‘late’ bilingual subject: Two distinct but adjacent centres of
activation were evident within the inferior frontal gyrus, suggesting that two specific regions
served each of the two languages. So distinct areas of activation were observed in Broca’s
area. In the posterior language area similar or identical cortical regions serve both languages.
So activity in Wernicke’s area shows smaller centre-to-centre distances.
The typical ‘early’ bilingual subject has very small centre-to-centre distance between the
centres of the two activity patterns in both areas.
So in Broca’s area, the activation sites for two different languages tend to be spatially distinct
when the seond language is obtained later in life, and in Wernicke’s area there is little or no
separation of activity regardless of age of acquisition.
So age of language acquisition may be a significant factor in determining the functional
organization of Broca’s area. Human infants, initially capable of discriminating all
phonetically ‘relevant’ differences, may eventually modify the perceptual acoustic space,
based on early and repeated exposure to their native languages. It is possible that
representations of languages in Broca’s area that are developed by exposure early in life are
not subsequently modified. This could necessitate the utilization of adjacent cortical areas for
the second language learned as an adult.
Learning goals
1. Effect of age on language development; organization of neural systems
2. Differences between ASL and normal language speakers in brain activation
3. Effect of age on acquisition and proficiency of bilingualism
1. Effect of age on language development; organization of neural systems
Kim
There might be spatially separate representations for each language. Participants performed
silent, internally expressive linguistic tasks in two languages by subjects who either acquired
conversational fluency in their second languages as young adults (‘late’ bilinguals) or who
acquired two languages simultaneously early in their development (‘early’ bilinguals).
Broca’s and Wernicke’s areas are known to perform central roles in human language
functions.
The main findings for a typical ‘late’ bilingual subject: Two distinct but adjacent centres of
activation were evident within the inferior frontal gyrus, suggesting that two specific regions
served each of the two languages. So distinct areas of activation were observed in Broca’s
area. In the posterior language area similar or identical cortical regions serve both languages.
So activity in Wernicke’s area shows smaller centre-to-centre distances.
The typical ‘early’ bilingual subject has very small centre-to-centre distance between the
centres of the two activity patterns in both areas.
So in Broca’s area, the activation sites for two different languages tend to be spatially distinct
when the seond language is obtained later in life, and in Wernicke’s area there is little or no
separation of activity regardless of age of acquisition.
So age of language acquisition may be a significant factor in determining the functional
organization of Broca’s area. Human infants, initially capable of discriminating all
phonetically ‘relevant’ differences, may eventually modify the perceptual acoustic space,
based on early and repeated exposure to their native languages. It is possible that
representations of languages in Broca’s area that are developed by exposure early in life are
not subsequently modified. This could necessitate the utilization of adjacent cortical areas for
the second language learned as an adult.
