PSY 369: Psycholinguistics

Language Acquisition:

Learning words, syntax, and more

Learning word meanings Learning words (a brief review)

One word stage Idiomorphs Over and under extension of meaning Generally:

one word per referent If it doesn’t work, pick a new word

How do the kids match the words to the referents?

Indeterminacy: Frog

FrogFrog?

Green?Ugly?

Jumping?

Quine’s gavagai problem The problem of reference:

a word may refer to a number of referents (real world objects)

a single object or event has many objects, parts and features that can be referred to

FrogFrog?

Green?Ugly?

Jumping?

Constraints on Word Learning

Perhaps children are biased to entertain certain hypotheses about word meanings over others

These first guesses save them from logical ambiguity get them started out on the right track

Markman (1989)

Object-scope (whole object) constraint Taxonomic constraint Mutual exclusivity constraint

Object-scope (whole object) constraint words refer to whole objects rather than to parts of

objects

Strategies for learning

‘Show me another lux’

‘Here is a lux’

Taxonomic constraint words refer to categories of similar objects taxonomies rather than thematically related obejcts

Strategies for learning

But in ‘no-word’ conditions, they would be shown the first picture

See this? Can you find another one?

Strategies for learning

4 and 5 year olds' choice of theme vs. category

-20

10

40

70

100

No word condition Novel word condition% Theme / Category

ThemeCategory

Strategies for learning

they choose the corkscrew because it is a less well known object for which they

don’t have a label yet.

‘Show me a dax’:

Mutual exclusivity constraint (Markam and Watchel 1988)

each object has one label & different words refer to separate, non-overlapping categories of objects

an object can have only one label

Strategies for learning

Problem with constraints

Most of the constraints proposed apply only to object names.

What about verbs? (Nelson 1988) There have been cases where children have been

observed violating these constraints using for example the word ‘car’ only to refer to ‘cars moving

on the street from a certain location’ (Bloom 1973) The mutual exclusivity constraint would prevent

children from learning subordinate and superordinate information (animal<dog<poodle)

The language explosion is not just the result of simple semantic development; the child is not just adding more words to his/her vocabulary.

Child is mastering basic syntactic and morphological rules.

Language explosion continues

Proto-syntax (?) Holophrases

Single-word utterances used to express more than the meaning usually attributed to that single word by adults

Language explosion continues

“dog” might refer to the dog is drinking water

May reflect a developing sense of syntax, but not yet knowing how to use it

Controversial claim (e.g., see Bloom, 1973)

Syntax Remember: word order is important! Basic child grammar (Slobin, 1985)

Similarities across all languages Mean length of utterance (MLU) in morphemes

Take 100 utterances and count the number of morphemes per utterance

Language explosion continues

Daddy coming. Hi, car. Daddy car comed. Two car outside. It getting dark. Allgone outside. Bye-bye outside.

# morphemes: 3, 2, 4, 3, 4, 2, 2‘-ing’ and ‘-ed’ separate morphemes‘allgone’ treated as a single word

MLU = morphemes/utterances = 20/7 = 2.86

Language explosion continues

0

1

2

3

4

5

6

0 10 20 30 40 50 60

age (months)

MLU

Syntax Roger Brown proposed 5 stages

Stage 1: Telegraphic speech (MLU ~ 1.75; around 24 months) One and two word utterances Debate: learning semantic relations or syntactic (position rules) Similar meaning to words used in 1 word stage:

Negation, nonexistence, call attention Soon branches out to other meanings (Brown, 1973)

Language explosion continues

Children in telegraphic speech stage are said to leave out the ‘little words’ and inflections:

e.g. Mummy shoe NOT Mummy’s shoe Two cat NOT two cats

More than two words Stages 2 through 5

Stage 2 (MLU ~2.25) begin to modulate meaning using word order (syntax)

Later stages reflect generally more complex use of syntax (e.g., questions, negatives)

Language explosion continues

Syntax Roger Brown proposed 5 stages

Innateness account Pinker (1984, 1989)

Semantic bootstrapping

How do kids learn the syntax?

Child has innate knowledge of

syntactic categories and linking rules

Child learns the meanings of

some content wordsChild constructs some semantic representations

of simple sentences Child makes guesses

about syntactic structure based on surface form and semantic meaning

“It is in the stimulus” accounts Children do not need innate knowledge to learn grammar

Speech to children is not impoverished (Snow, 1977) children learn grammar by mapping semantic roles (agent, action,

patient) onto grammatical categories (subject, verb, object) (e.g. Bates, 1979)

How do kids learn the syntax?

Morphology Typically things inflections and prepositions start around

MLU of 2.5 (usually in 2 yr olds) Wug experiment (Berko-Gleason, 1958)

Language explosion continues

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

Here is a wug.

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.QuickTime™ and a

TIFF (LZW) decompressorare needed to see this picture.

Now there are two of them.

There are two _______.

Morphology Lists of forms Rules Overregularization

Language explosion continues