Normal Language Acquisition Chapter 5

mental lexicon

the store of word knowledge

Each word is an…

entry

Each entry specifies

-the sound of the word

-the grammatically category

-the word’s meaning

what is a word?

they are symbols: they stand for something without being part of that something

The relationship between the word and symbol is…

arbitrary

Words have…

reference-they refer to things

-words “stand for” referents (things)

First words appears between…

10 and 15 months of age

Context-bound word

first words may be tied to particular context (like the protowords the preceded them)

Categorized first words into 3 groups

-context bound- largest category

-contextually flexible nominals – names for things

-Contextually flexible, but not nominals

Words that are at first context bound gradually become

decontextualized

About 18 months, ranging from 15 to 24 months

children achieve a productive vocabulary of 50 words

Nelson (1973)

Classified first 50 words into six categories:

• Specific nominals (mommy, daddy)

• General nominals: common nouns

• Action words like up, go

• Modifiers such as big, all gone

• Personal social words like no

• Grammatical function words like what, is, for

First words reflect…

experiences

What is the source of early expressions?

routines

What percentage of vocabulary for english speaking children is made up of nouns and verbs?

45%; 3%

Natural partitions hypothesis

physical world makes obvious the things that take nouns as labels, whereas the meanings that verbs encode have to be figured out from hearing the verb in use

relational relativity hypothesis

Verb meanings must be figured out from use – they do not naturally emerge from the structure of the word and may mean that verb meanings will vary from language to language

underextensions

More restricted or narrow use

overextensions

More noticeably, children sometimes use their words more broadly than the true meaning allows

During the first months after first words

children add an average of 8 to 11 words each month to their vocabularies

word spurt

Once children hit 50 word milestone, vocabulary increases an average

rate of 22 to 37 words per month (around 18 months)

“naming insight”

realize everything has a name

Word learning begins

months before children speak their first words

As early as 5 months show evidence

they recognize their own names

8 months

understand a few phrases

8 – 10 months

children start to understand the meanings of

individual words

16 months of age

children have comprehension vocabularies

between 92 and 321 words

“looking-while-listening” procedure

found between 15 and 25 months, children increase in speed of verbal processing

Holistic manner

acquire big chunk

Sociability

More social and interested in social interaction would want a vocabulary of words to use in particular situations

Referential language style

children with more object labels in their vocabularies

Expressive language style

= children with fewer object labels and more personal/social words

Two variables associated with differences in rate

- Socioeconomic status (SES)

• Birth order

Hold age constan

Higher SES = bigger vocabularies

• Mothers in higher SES talk more to children and have a richer vocabulary

• First born have slightly larger vocabularies

• More 1:1 interaction experience with an adult

Two factors with clear relations to rate of vocabulary growth

-Speech of processing

• phonological memory

Speech segmentation

Child must find the word boundaries in a continuous stream of sound

Indeterminacy of word meaning or the mapping problem

Once a child has successfully identified a word in the speech stream,

he or she must tackle the next problem: what does this new word

refer to?

Fast mapping

children may begin by making an initial fast mapping

between a new rod they hear and a likely candidate meaning

lexical principles or lexical constraints

children have knowledge (either innately or derived from experience)

about how the lexicon works

whole-object assumption

assumption that words refer to whole objects

rather than to part of an object or a property of the object

assumption of mutual exclusivity

assumption that different words refer to different kinds of things

pragmatic principles

How language is used

Principle of conventionality

meaning of a word is determine by convention; has to

be agreed upon and observed by all members of language community

Principle of contrast

different words have different meanings

syntactic bootstrapping hypothesis

Proposal that knowledge of language structure is generally useful for learning new verbs

Specificity to word learning

Knowledge of lexical constraints is

useful only for the task of learning new words

Endogenous

within the child

Exogenous

outside the child

Taxonomic assumption

words refer to things that are of the same kind

lexical organization

In this chapter, we discuss how children learn the semantics of their

language with respect to the lexicon