SLA Lecture+2

7/28/2019 SLA Lecture+2

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LECTURE 2

Factors influencing language acquisition(Part 1: AGE)

BBI 5210

Second Language Acquisition


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Some important observations

Children learning their first language accomplish it byage 4-6 years

L2 learner start learning the L2 at a variety of age; two

hotly debated issues related to age and SLA Is there a critical period for language learning?

Critical Period Hypothesis YES; but there is evidence against thishypothesis

Is there a ceiling effect for second language learning?

Ultimate attainment / End State for L2

Is it possible for L2 learners to attain a level of competence in the L2that is isomorphic to the competence that all humans possess in theirown mother tongue / L1


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Critical Period Hypothesis/ Sensitive Period

There is a specific period of time early in life whenthe brain exhibits a special propensity to attend tocertain experiences in the environment (e.g.

language) and learn from them.

The brain is pre-programmed to be shaped byexperience, but only if it occurs within a biologically

specified time period.


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Evidence of critical/sensitive periodsin animal learning

There appears to be a distinction between critical andsensitive periods in animal learning too Critical period: irreversible damage

e.g. ocular development in the brains of kittens:

kittens deprived of experience of viewing between 30-80days of life will lose vision

Sensitive period: reversible if sufficient stimuli is later provided

e.g. barn owls use auditory cues to create mental maps of

their space. If hearing/vision is impaired during thesensitive period, auditory spatial information will not beprocessed normally later in life; affecting their survival asthey will not beable to catch mice in the dark


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Evidence for the Critical Period Hypothesis forlanguage learning

Genie (watch youtube secret of the wild child)

A child discovered in 1970 at the age of 13 having beenbrought up in conditions of inhuman neglect andextreme isolation, was unable to learn language.

Other feral children (children who lived out of humancontact from a young age)

Postponed L1 acquisition: deaf babies exhibit incompleteacquisition of their late-learned first language


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Evidence for a sensitive period

Svirsky and Holt (2005)

Deaf babies who receive the coclear implant after age2 show slower progress and overall lower

performance in vocabulary and grammar comparedto those who receive them before age 2.

Suggest: 2 years of age may be the sensitive period


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Extension of Critical Period Hypothesis to L2A

Observations:1. L2 learners who start earlier during childhood are more

successful (in terms of ultimate attainment)

Early explanations from neurolinguistics:1. Penfield and Roberts, 1959: loss ofplasticityin the

human brain by the age of nine2. Lenneberg, 1967: completion of the process of

lateralization with the onset of puberty

BUT these explanations are now being challenged; butmany still accept them as plausible.


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Neuroscience terminologies

Plasticity: the ability of the brain to changeWith loss of plasticity, the brain structure is fixed / unchangable

see neuroscience resources for kids

http://faculty.washington.edu/chudler/plast.html

Lateralization: Left brain and right brain functions

Most mental functions are distributed across the hemispheresbut there are specific processes that are specialized to one

hemisphere. For example, both sides of the brain performfunctions related to language. But in most people, grammarand vocabulary are localized to the left side of the brain, whileunderstanding the emotional content of language is a functionof the right hemisphere.


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Language is a biological system

Lenneberg (1967:371-4) argues that a system is biological if itsatisfies these 5 criteria:

its cognitive function is species specific the specific properties of its cognitive function are replicated

in every member of the species Thecognitive processes and capacities associated with this

system are differentiated spontaneously with maturation Certain aspects of behavior and cognitive function for this

system emerge only during infancy Certain social phenomena come about by spontaneous

adaptation of the behavior of the growing individual to thebehavior of other individuals around him


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Evidence against the critical period hypothesis ?

Exceptionally successful late L2 learners (Ioup et al., 1994)e.g. Julie (L2 learner of Arabic) started at age 21

lived in Egypt for 26 years naturalistic learner

Tests conducted:1. Production task: 7 /13 judged her speech as definitely native2. Perception task: able to discriminate Egyptian from non-

Egyptian accents3. Translation task: made very few mistakes4. Grammaticality judgement task: diverged on 5/37 sentences from

native speakers

Do the above evidence support or argue against the critical periodhypothesis / sensitive period? What do you think? What kinds ofevidence would be more definitive?


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Are children or adults better L2 learners?

Snow and Hhle (1978) : in a 25-minute instructionsession, adults and adolescents were better than inchildren

Krashen, Long and Scarcella (1979): older is betterinitially, but younger is better in the long run

Oyama (1976) and Patkowski (1980): longitudinalstudies that show the rate advantage for adults dissipatesafter a little while and children eventually catch up

However, in a foreign language context, this may not bethe case, because exposure to L2 is limited to whatsavailable in the classroom.


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The importance of Context

Age may exert universal influences on the learning of asecond language, but context moderates these universaleffects.

Hours of exposure to linguistic input:L1 acquisition: 14000 hours

( 5 years x 365 days x 8 hours)

L2 acquisition: 7000 hours

( 4 hours x 365 days x 5 years)Foreigen language context L2 learning: 540 hours

( 3 hours x 4 weeks x 9 months x 5 years)


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The question of ultimate attainment

Two lines of research both focusing on L2 morphosyntax

Correlational Studies: L2 morphosyntactic knowledgealong the age of onset continuum

Q: Are age and morphosyntactic attainment related?

Grammatical Judgement Task

Q: Can some exceptionally successful L2 acquirers beindistinguishable from the native speakers in theirmorphosyntactic knowledge?

Can native-like competence be achieved?


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Correlational Studies

Johnson and Newport (1989):

Youngest group performed within the range of native speakers

Older group (8-16) showed scored linearly declining with age

Adults group : no relation between age and grammatical

judgement

Birdsong and Molis (2001) replicated Johnson and Newport

And found a negative correlation for the whole sample group

Early arrivals had perfect scores 13 late arrivals obtained 92% and 3 > 95%


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On ultimate attainment

Coppieters (1987): subjects all learned L2 after puberty Grammatical intuitions were 3 SD away from native

controls. Rationalization in interviews were also

different. There were subtle syntactic-semantic andmorphosemantic differences were found

Birdsong (1992): partial replication of Coppieters (1987) Subjects also learned L2 after puberty 15 participants performed in the same range as native

speakers


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The debate goes on!!

Cognitive neuroscience

What causes age effects?

Biological or other explanations

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