Chapter 6 Development of Language and Symbols

1. Chapter 6 • Development of Language and Symbols

2. Language • Language Comprehension • Understanding what others are saying • Language Production • Actual speaking • Language Comprehension • precedes • Language Production

3. Prerequisites for Language • Human Brain • Species-specific: only humans acquire language • Species-universal: almost all young humans learn language • Brain–Language Relations • Left hemisphere specialization increases with age • Broca’s aphasia and Wernicke’s aphasia • Critical periods • Victor, the “Wild Child”; Genie • Brain damage in adulthood is more likely to be permanent than brain damage in childhood • Second language learning in adulthood

4. Lateralization of language In most people, the left hemisphere of the cerebral cortex is specialized for language. Damage to Broca’s and Wernicke’s areas can produce severe impairments in language functions, known as aphasia.

5. Hemispheric differences in language processing Adults who learned a second language at 1 to 3 years of age show the normal pattern of greater left-hemisphere activity in a test of grammatical knowledge. (Darker colors indicate greater activation.) Those who learned the language later show increased right-hemisphere activity. (Adapted from Neville & Bavelier, 1999)

6. Test of critical-period hypothesis Performance on a test of English grammar of adults originally from Korea and China is directly related to the age at which they came to the United States and were exposed to English. The scores of adults who emigrated before the age of 7 are indistinguishable from those of native speakers of English. (Adapted from Johnson & Newport, 1989)

7. Environment • Infant-directed speech (IDS) (motherese or parentese) • Characteristics of IDS: • Emotional tone • Slow and clear • Exaggerated speech • Exaggerated facial expressions • Intonation reflects meaning (e.g., approval or disapproval) • Infants like IDS better than regular speech • Infants learn more words in IDS • IDS is not universal

8. Acquiring Language • Speech Perception • Prosody—the characteristic rhythm, tempo, cadence, melody, intonation pattern, etc., with which language is spoken • Categorical Perception • In both adults and infants speech sounds are perceived as belonging to discrete categories

9. Categorical perception of speech sounds by infants

10. Categorical perception of speech sounds by infants One- and four-month-old infants were habituated to a tape of artificial speech sounds. One group repeatedly heard a /ba/ sound with a VOT of 20, and they gradually habituated to it. When the sound changed to /pa/, with a VOT of 40, they dishabituated, indicating that they perceived the difference between the two sounds, just as adults do. Another group was habituated to a /pa/ sound with a VOT of 60. When the sound changed to another /pa/ with a VOT of 80, the infants did not dishabituate, suggesting that, like adults, they did not discriminate between these two sounds. (Adapted from Eimas et al., 1971)

11. Phonemes Morphemes Syntax Pragmatics Semantic Development: learning about expressing meaning Syntactic Development: learning rules for combining words Pragmatic Development: learning how language is used Phonological Development: learning about the sound system of a language Components of Language

12. Early Interactions • Before they can speak, infants show communicative competence, intentional communication with another person • Turn-taking: Peek-a-boo • Intersubjectivity • Joint Attention

13. First Words • Infants can clearly recognize words between 7–8 months • Around 10 months, infants can comprehend 11 to 154 words • Word Production • Begins between 10 and 15 months • Holophrastic period • Styles: • Referential or analytic style • Expressive or holistic style • Wait-and-see style

14. Language achievement On average, American children say their first word at around 13 months, experience a vocabulary spurt at around 19 months, and begin to produce simple sentences at around 24 months. However, the bars around the means show that there is great variability in when different children achieve each of these milestones. (Adapted from Bloom, 1998)

15. Typical Early Words CHILD WORDS Jane Daddy, Mommy, Daniel, girl, ball, cracker cookie, that, school, bye Mark Ma, dog, milk, water, car, here, bye-bye, no Lisa Daddy, Mommy, Daisy, puppy, ball, see, hi © 1999 John Wiley and Sons, Inc.

16. 2+ Words • Sentences • Telegraphic speech • Sentences usually start around the end of the 2nd year • Practice results in longer sentences • Grammar Rules • Overregularization: e.g., foot—foots • Around age 2, children begin using “wh” questions • Before age 3 children begin using negatives, “No” • Over time children will slowly use correct grammar • Parents ignore grammar, but correct false statements

17. Interactionist (communicative functions of Language) • Language is a social skill • Children are motivated to communicate • Children pay close attention to language • Evidence: • Infants’/children’s sensitivity to pragmatic cues • Problem: • Nativists believe that sheer focus can not teach complex grammar

18. Connectionist • Language develops from strengthening neural connections • Evidence: • Infants can identify structural features of language • Problems: • Much of this is based on models and much is not modeled yet

19. Nonlinguistic Symbols • Symbols as information • Dual representation • Children age 2½ can not do this • Pretend Play • Around 18 months infants make object substitutions, but these become more complex with time • Drawing • Around age 2½ children narrate what they are drawing • Between ages 3–4 children attempt to draw something • Children have more advanced ideas than they do motor/planning capabilities • Human faces are the most common thing to draw