Transcript PSY 369: Psycholinguistics - the Department of Psychology at

PSY 369: Psycholinguistics
Language Acquisition II
Where to from here?
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Learning Morphology
Critical periods in language learning
Bilingualism
Language, culture, and thought
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Left out: Language and the brain
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Read the chapter, take the quiz, but no
lecture and won’t appear on final exam
Language explosion continues
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Morphology
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Typically things inflections and prepositions start around
MLU of 2.5 (usually in 2 yr olds)
Wug experiment (Berko-Gleason, 1958)
Language explosion continues
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Morphology
This person knows how to rick. She did the same thing yesterday.
Yesterday she ________.
Typically children say that she “ricked.”
Acquiring Morphology
Order
Morpheme
Example(s)
1
Present progressive
I driving
1-2
Prepositions
In, on
4
Plural
Balls
5
Irregular past tense
Broke, fell, threw
6
Possessive
Daddy’s chair
7
Uncontractible copula
This is hot
8
Articles
A, the
9
Regular past tense
She walked
10 -> 13 …
…
Table 11.2 in text
Acquiring Morphology
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Children sometimes make mistakes.
I holded the baby rabbits.
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This is ungrammatical in the adult language
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Shows that children are not simply imitating
In this case, what they produce something that is not in their
input.
Acquiring Morphology
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Children sometimes make mistakes.
I holded the baby rabbits.
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Why do they make errors like these?
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In the case at hand, we have what is called overregularization
The verb hold has an irregular past tense form, held
Because this form is used, the regular past tense-- that with ed-- is not found (*hold-ed)
Regular and irregular forms
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Remember that regular forms require no stored
knowledge of the past tense form (wug test)
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Past tense is accomplished by applying a past tense rule
(e.g., add -ed) to the verb stem
Whereas something must be memorized with
irregulars
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Examples:
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Horton heared a Who
I finded Renée
The alligator goed kerplunk
Acquiring Morphology
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Stages in the acquisition of irregular inflections
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With regular verbs, the default form -ed is used
With irregulars, lists associating the verb with a particular
form of the past tense have to be memorized:
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Past tense is -t when attached to leave, keep, etc.
Is -> was
Dig -> dug
Has -> had
Acquiring Morphology
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Stages in the acquisition of irregular inflections
time
Step
1
2
3
4
5
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Description
No inflection
Adult form
Overregularization
Transition
Adult form
Noun
Man
Men
Mans
Mens
Men
Examples
Verb
Adjective
Go
Bad
Went
Worse
Goed
Badder
Wented Worser
Went
Worse
On the face of it, learning these morphological quirks follows a
peculiar pattern:
 Early: correct irregular forms are used
 Middle: incorrect regular forms are used
 Late: correct forms are used again
Why do we find this type of pattern?
 Memory and rules
Memory & Rules
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The use of overregularized forms starts at around the same that
that the child is beginning to apply the default -ed rule
successfully
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Early: All forms-- whether regular or irregular-- are memorized
Middle: The regular rule is learned, and in some cases
overapplied
Late: Irregulars are used based on memory, regulars use the rule
(the idea is that if the word can provide its own past tense from
memory, then the past tense rule is blocked)
Memory & Rules
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It is possible to predict which verbs will be subject to
overregularization
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We find a frequency effect
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The more often an irregular form occurs in the input, the less
likely the child is to use it as an overregularization
This is evidence that some part of overregularization occurs
because of memory failures
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Something about irregulars is unpredictable, hence has to be
memorized
Interim Summary
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Overregularization looks at first like children are
moving backwards
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On closer examination, the child’s overall performance is
improving
The pattern of overregularization provides a window on the
process in which the child (over)generalizes a rule
So how is the rule learned (learnt?)
What kind of “teaching” do kids get?
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Are the kids even aware of mistakes?
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The children are apparently aware of the fact that their
forms are strange:
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Parent: Where’s Mommy?
Child: Mommy goed to the store
Parent: Mommy goed to the store?
Child: NO! Daddy, I say it that way, not you
Positive and negative evidence
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What kind of feedback is available for learning?
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Positive evidence: Kids hear grammatical
sentences
Negative evidence: information that a given
sentence is ungrammatical
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Kids are not told which sentences are ungrammatical
(no negative evidence)
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Let’s consider no negative evidence further…
Negative evidence
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Negative evidence could come in various
conceivable forms.
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“The sentence Bill a cookie ate is not a sentence in
English, Timmy. No sentence with SOV word order
is.”
Upon hearing Bill a cookie ate, an adult might
 Not understand
 Look pained
 Rephrase the ungrammatical sentence
grammatically
Kids resist instruction…
McNeill (1966)
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Child: Nobody don’t like me.
Adult: No, say ‘nobody likes me.’
Child: Nobody don’t like me.
[repeats eight times]
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Adult: No, now listen carefully; say ‘nobody likes me.’
Child: Oh! Nobody don’t likes me.
Kids resist instruction…
Cazden (1972) (observation attributed to Jean Berko Gleason)
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Child: My teacher holded the baby rabbits and we patted them.
Adult: Did you say your teacher held the baby rabbits?
Child: Yes.
Adult: What did you say she did?
Child: She holded the baby rabbits and we patted them.
Adult: Did you say she held them tightly?
Child: No, she holded them loosely.
So there doesn’t seem to be a lot of explicit negative evidence, and
what there is the kids often resist
Negative evidence via feedback?
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Do kids get “implicit” negative evidence?
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Do adults understand grammatical sentences and not
understand ungrammatical ones?
Do adults respond positively to grammatical sentences
and negatively to ungrammatical ones?
Negative evidence via feedback?
Brown & Hanlon (1970):
Case study of “Adam” - looked at things that were said to
him by adults, and what he said to them
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Adults understood 42% of the grammatical sentences.
Adults understood 47% of the ungrammatical ones.
Adults expressed approval after 45% of the
grammatical sentences.
Adults expressed approval after 45% of the ungrammatical
sentences.
Suggests that there isn’t a lot of good negative evidence.
In a way, it’s moot anyway…
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One of the striking things about child language is how few
errors they actually make.
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For negative feedback to work, the kids have to make the errors
(so that it can get the negative response).
But they don’t make enough relevant kinds of errors to determine
the complex grammar.
Pinker, Marcus and others, conclude that much of this stuff
must be innate.
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But this isn’t the only view. There is a raging debate about
whether there are rules, or whether these patterns of behavior
can be learned based on the language evidence that is available
to the kids
Critical (sensitive) periods
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Certain behavior is developed more quickly
within a critical period than outside of it. This
period is biologically determined.
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Examples:
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Imprinting in ducks (Lorenz, ; Hess, 1973)
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Ducklings will follow the first moving thing they see
Only happens if they see something moving within the first
few hours (after 32 hours it won’t happen) of hatching
Binocular cells in humans
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Cells in visual system that respond only to input from both
eyes.
If these cells don’t get input from both eyes within first year
of life, they don’t develop
Critical (sensitive) periods
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Certain behavior is developed more quickly
within a critical period than outside of it. This
period is biologically determined.
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Some environmental input is necessary for normal
development, but biology determines when the
organism is responsive to that input.
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That “when” is the critical period
Critical period for language
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Lenneberg (1967) proposed that there is a critical
period for human language
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It assumes that language acquisition must occur
before the end of the critical period
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Estimates range from 5 years up to onset of puberty
Evidence for critical period for language
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Feral Children
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Children raised in the wild or with reduced exposure to
human language
What is the effect of this lack of exposure on language
acquisition?
Two classic cases
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Victor, the Wild Boy of Aveyron
Genie
Victor, The Wild Boy of Aveyron
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Found in 1800 near the outskirts of Aveyron, France
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Estimated to be about 7-years-old
Considered by some to be the first documented case of autism
Neither spoke or responded to speech
Taken to and studied by Dr. Jean-Marc-Gaspard Itard, and
educator of deaf-mute and retarded children
Never learned to speak and his receptive language ability was
limited to a few simple commands.
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Described by Itard as “an almost normal boy who could not speak”
Genie
QuickT ime ™an d a TIFF (L ZW) dec ompr esso r ar e need ed to see this pictur e.
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Found in Arcadia, California in 1970, was not
exposed to human language until age 13.5.
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Raised in isolation a situation of extreme abuse
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Genie could barely walk and could not talk when
found
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Dr. Susan Curtiss made great efforts to teach her
language, and she did learn how to talk, but her
grammar never fully developed.
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Only capable of producing telegraphic utterances
(e.g. Mike paint or Applesauce buy store)
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Used few closed-class morphemes and function
words
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Speech sounded like that of a 2-year-old
Genie
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By age of 17 (after 4 years of extensive training)
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Vocabulary of a 5 year old
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Poor syntax (telegraphic speech mostly)
QuickT ime ™an d a TIFF (L ZW) dec ompr esso r ar e need ed to see this pictur e.
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Examples
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Mama wash hair in sink
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At school scratch face
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I want Curtiss play piano
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Like go ride yellow school bus
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Father take piece wood. Hit. Cry.
What Do These Cases Tell Us?
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Suggestive of the position that there is a critical
period for first language learning
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If child is not exposed to language during early childhood
(prior to the age of 6 or 7), then the ability to learn syntax will
be impaired while other abilities are less strongly affected
Not uncontroversial: Victor and Genie and children like them
were deprived in many ways other than not being exposed to
language
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Genie stopped talking after age 30 and was institutionalized
shortly afterward (Rymer, 1993)
Effects of the Critical Period
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Learning a language;
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Under c. 7 years: perfect command of the language possible
Ages c. 8- c.15: Perfect command less possible
progressively
Age 15-: Imperfect command possible
In some special cases, we are given a window on the
nature of the critical period
Effects of the Critical Period
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Learning a new language
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What if we already know one language, but want to learn
another?
Effects of the Critical Period
Johnson and Newport (1989)
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Native Chinese/Korean speakers moving to US
Task: Listen to sentences and judge whether
grammatically correct
Age and Second-language acquisition
mean score on
English grmmar test
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280
270
260
250
240
230
220
210
200
native
3 to 7
8 to 10
age of arrival
11 to 16
17 to 39