Lexical Acquisition

THE PERIOD OF SINGLE WORD UTTERANCES

A. Definition

   1. Does the word have to be produced correctly?

   2. Does the word have to be understood correctly?

3. Children can have their own understanding of words with little connection to the adult meaning.

B. Onset and Rate

   1. Charlotte Buhler (1931) production data from 46 German children average age at first word was 0;10

   2. Madorah Smith (1926) studied 124 English-speaking children

   3. Helen Benedict (1979 JCL)

      A. Method: studied 8 children for 6 months; asked mothers to keep diaries

            i. Phase I: visited every other week for 6 months for 45-90 minutes

            ii. Phase II: continued until age 2;0 or MLU 1.10

            iii. scored the age at which a preset number of words were acquired

      B. Results

            i. Comprehension is four months ahead of production

            ii. The rate of acquisition for comprehension was faster than the rate for production

                  e.g., 2 weeks to acquire 10 words in comprehension

                          4 weeks to acquire 10 words in production

            iii. Rates of acquisition differ for individual subjects

                  Number of words

                  Rate for first 50 words (days/word)

Lexical acquisition at later ages (P. Bloom 2002: 44)

References

Anglin, J. 1993. Vocabulary development: A morphological analysis. Monographs of the Society

   for Research in Child Development 58:1-166.

Bloom, Paul. 2002. How Children Learn the Meanings of Words. Cambridge, MA: MIT Press.

Dromi, E. 1987. Early Lexical Development. Cambridge: Cambridge University Press.

Fenson, L., Dale, P. S., Reznick, J. S., Bates, E., Thal, D., and Pethick, S. J. 1994. Variability in

   early communicative development. Monographs of the Society for Research in Child

   Development 59.

Hart, B. and Risley, T. R. 1995. Meaningful Differences in the Everyday Experience of Young American Children. Brookes Publishing Company.

C. General Semantic Categories

   1. Katherine Nelson (1973 Structure and Strategy in Learning to Talk)

      A. Method: studied the first 50 words of 18 children; asked mothers to keep diaries

      B. Divided the children’s words into 5 general categories

            i. Specific nominals: words that refer to only one exemplar of a category, e.g., ‘Daddy’

            ii. General nominals: words which refer to all members of a category, e.g., ‘this’

            iii. Action words: words that elicit or accompany actions of the child, e.g., ‘peekaboo’

            iv. Modifiers: words that refer to properties or qualities of things or events, e.g., ‘big’

            v. Personal-social: words that express affective states, e.g., ‘yes’, ‘want’, ‘bye-bye’

      C. Results

            i. early use of general nominals

            ii. over time the use of specific nominals decreases and general nominals increase

            iii. The children used two different strategies: expressive and referential

      D. Discussion

            i. Is the referential/expressive distinction real?

            ii. What might cause such a distinction?

                  a. performance differences–what do the children happen to enjoy doing

                  b. input–Nelson found evidence against this cause

                  c. linguistic variation–children focus on lexicon or pragmatics

      E. Benedict (1979) reported a different distribution in comprehension and production

F. Dedre Gentner (1982 ‘Why Nouns are Learned Before Verbs’ in S. Kuczaj (ed.) Language

              Development, Vol.2 Erlbaum.)

      . Natural Partitions Hypothesis: the category corresponding to nouns is, at its core, conceptually simpler or more basic than those corresponding to verbs and other predicates.

      Data

      Other Explanations:

            i. Word Order–Easier to remember the last words in sentences

            ii. Morphological Transparency–Nouns have fewer inflections

            iii. Input Frequency

Gentner & Boroditsky (2001) “One might suggest, then, that there is nothing to explain: children’s word distributions simply match those of adults, with many nouns and a few highly frequent relational words. But to say the patterns match does not provide a mechanism of learning.” (p. 232)

            iv. Patterns of Language Teaching–Kaluli and Chinese parents emphasize family names

Recent literature

P. Brown. (1998) Children’s first verbs in Tzeltal. Linguistics 36.715-753.

S. Choi & A. Gopnick. (1995) Early acquisition of verbs in Korean. JCL 22.497-529.

D. Gentner & L. Boroditsky. (2001) Individuation, relativity, and early word learning. In M. Bowerman & S. Levinson (eds), Language Acquisition and Conceptual Development. Cambridge.

L. de León. (1999) Verbs in Tzotzil early syntactic development. International Journal of Bilingualism 3.219-240.

C. Pye (1992) The acquisition of K’iche’ Maya. In D. Slobin (ed.), The Crosslinguistic Study of Language Acquisition, Vol. 3, pp. 221-308. Hillsdale, NJ: Erlbaum.

T. Tardif. (1996) Nouns are not always learned before verbs. Developmental Psychology 32.492-504.

D. Development of Lexical Meaning

   1. Children’s first words are restricted to limited contexts (Snyder, Bates & Betherington 1981)

      A. Analyzed contextual flexibility of 32 children’s first 50 words (mean age 1;1(7))

   2. Early words in Nelson’s (1973) study (Table 6.7)

   3. Semantic overextensions

      A. Braunwald (1978) kept a diary of her daughter Laura

      B. Vygotsky (1962) associative complex

      C. Rescorla (JCL 1980), Production

            1. Collected diary observations for the first 75 words in production for 6 children (1;0-1;6)

            2. Data: 6 subjects x 75 words = total of 455 words observed

            3. Children only overextended 149 words (33%!)

            4. Category differences: letters 100%, vehicles 76%, animals 28%

5. 12 words constitute 37% of overextensions: car, truck, shoe, hat, Dada, cheese, ball, cat, dog, hot

            6. Rescorla divided the overextensions into three types:

                  a. categorical (extended within a category) 55%, e.g. ‘Dada’- mother, ‘apple’- orange

                  b. analogical (no clear categorical relation) 19%, e.g. ‘hat’- basket on child’s head

                  c. predicative (word used as predicate for absent referent) 25%, e.g. ‘doll’ - doll place

            7. Overextensions continue through whole period (seven months)

                  11% 9% 24% 29% 28% 28% 24%

            8. Earliest acquired words were overextended the most

                  1-25    45%

                  26-50  35%

                  51-75  20% (due to shorter time to observe these words?)

            9. associative complexes account for 58 or 39% of overextensions (Table 6.9, p. 152)

                  ‘daddy’, ‘key’, ‘hot’, ‘mommy’, ‘hat’, ‘cheese’

      D. Thomson & Chapman (JCL 1977), Comprehension

            1. It is much harder to observe children overextending words in comprehension

            2. Studied 5 children, age 22.4 months, MLU 1.55

            3. Selected 4 words from each child’s diary that were overextended in production

            4. Used pictures of familiar and unfamiliar referents, e.g. ‘daddy’- daddy, mother, stranger

            5. Production task: labeled at least 5 pictures correctly and ten pictures incorrectly

6. Comprehension task: children were shown 10 pairs of appropriate and inappropriate pictures

                  Children responded to either ‘Show me the X’ or ‘Where is X’?

                  Overextended if correct picture chosen 7 times or less, i.e. less than 80%

            7. Results (Table 6.10, p. 155)

      E. Explanation of children’s semantic extensions

            1. Children have incomplete linguistic sign (Piaget 1948)

                  a. children only overextend a small percentage of their first words (33%)

                  b. older children continue to overextend words

c. word spurt occurs in comprehension before production providing evidence that children have acquired full symbolic reference

d. definition of incomplete linguistic sign is circular; it refers to how children use words

            2. Incomplete Semantic System - children lack adult system of semantic contrasts

            3. Limited Vocabulary - children only overextend words in production

            4. Retrieval Problem - children tend to overextend words acquired earlier/retrieved faster

5. Phonological Simplicity - children favor words with known sounds (Schwartz & Leonard 1982)

            6. All of the above?

E. Syntactic Comprehension–do children know more than they produce?

   1. Shipley, Smith & Gleitman (1969)

      a. Subjects: holophrastic and telegraphic groups of children

      b. Method: mothers gave three types of commands:

      Children scored on whether they touched or looked at the object, or followed the commands

      c. Results (% touch): (Tables 6.12 & 7.6)

‘... all holophrastic speakers obey more often with single-word commands than with well-formed commands’. ‘all telegraphic speakers obey more often with well-formed commands than with single word commands ... The results for VN are similar but less sharp’ (329).

Later claimed study did not directly test syntactic comprehension, but only children’s responses to different types of parent commands.

   2. Sachs & Truswell (1978)

      a. Subjects: 12 children between 1;4 and 2;0 who were only producing single-word utterances

b. Method: presented novel Action + Object sentences combining words in the children’s receptive vocabularies, e.g.,

            Smell truck

            Smell dolly

            Kiss truck

            Kiss dolly

            Each child given an average of 16 commands.

      c. Results: 58% of responses were correct, 16% were incorrect, 6% elicited no response

10 of 11 children receiving four-way minimal contrasts got at least one set correct. The youngest child (1;4) performed correctly on a two-way contrast (‘Kiss horsey’ vs. ‘Kiss teddy’).

d. Conclusion: Children using single-word utterances can understand novel Action + Object commands.

   3. Miller, Chapman, Bronston & Reichle (1980)

      a. Subjects: 12 children aged 10-12 months, 13-15 months, 16-18 months, and 19-21 months

      b. Method: tested the children’s comprehension of eight items (Table 6.13):

      c. Results–number of subjects passing comprehension task (Table 6.14, p. 168):