PSY 369: Psycholinguistics

1. PSY 369: Psycholinguistics Language Acquisition III

2. Brief outline • Continue describing the acquisition of language: syntax and morphology • Some topics in the innateness (nativism vs. empiricist) debate: • What kind of feedback (teaching) do kids get? • Is there a critical period for language?

3. Language explosion continues • 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 processes.

4. Language explosion continues • Syntax • Mean length of utterance (MLU) in morphemes • Take 100 utterances and count the number of morphemes per utterance 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

5. Language explosion continues • Syntax • Mean length of utterance (MLU) in morphemes

6. Language explosion continues • Proto-syntax (??) • Holophrases (around 1-1.5 years) • Single-word utterances may be used to express more than the meaning usually attributed to that single word by adults “dog” might refer to the dog is drinking water • Typically idiosyncratic, but some conventional/common (e.g., indicate the existence of an object, request recurrence of object or event) • Often combined with intonation or gesture • Controversial claim: May reflect a developing sense of syntax, but not yet knowing how to use it (e.g., see Bloom, 1973)

7. Language explosion continues • Syntax • Roger Brown (1973) proposed 5 stages • Stage 1: Telegraphic speech (MLU ~ 1.75; around 24 months) • Children begin to combine words into utterances • Limited to a small set of semantic relations (e.g., nomination, recurrence, attribution, possession [see table 10.3 for examples]) • Debate: learning semantic relations or syntactic (position rules) • “baby sleep” agent+action or Noun Verb • 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

8. Language explosion continues • More than two words • Stages 2 through 5 • Stage 2 (MLU ~2.25) • begin to modulate meaning using word order (syntax) • Modulations for number, time, aspect • Gradual acquisition of grammatical morphemes (“-ing”, “-s” • Later stages reflect generally more complex use of syntax (e.g., questions, negatives) • Syntax • Roger Brown (1973) proposed 5 stages

9. How do kids learn the syntax? • Innateness accounts • Semantic bootstrapping • Learned accounts • Acquired from the linguistic input from the environment • It is in the stimulus

10. How do kids learn the syntax? • Innateness account • Pinker (1984, 1989) • Semantic bootstrapping Child has innate knowledge of syntactic categories and linking rules Child learns the meanings of some content words Child constructs some semantic representations of simple sentences Child makes guesses about syntactic structure based on surface form and semantic meaning

11. How do kids learn the syntax? • “It is in the stimulus” accounts (e.g. Bates, 1979) • Speech to children is not impoverished (Snow, 1977) • Children learn grammar by mapping semantic roles (agent, action, patient) onto grammatical categories (subject, verb, object) • In all languages there are multiple potential cues indicating semantic/syntactic relations (e.g., word order, case marking) • Similar words occur in similar linguistic contexts • Acoustic information (e.g., prosody) may provide syntactic cues • Children do not need innate knowledge to learn grammar

12. Acquiring Morphology • Morphology • Typically things like inflections and prepositions start around MLU of 2.5 (usually in 2 yr olds) • Remember the Wug experiment (Berko-Gleason, 1958)

13. Acquiring Morphology • Morphology This person knows how to rick. She did the same thing yesterday. Yesterday she ________. Typically children say that she “ricked.”

14. Acquiring Morphology • Morphology: order of acquisition

15. Acquiring Morphology • Children sometimes make mistakes. My teacher holded the baby rabbits. Yes She holded the baby rabbits. No, she holded them loosely. Did you say your teacher held the baby rabbit? What did you say she did? Did you say held them tightly?

16. Acquiring Morphology • Children sometimes make mistakes. • This is ungrammatical in the adult language • Shows that children are not simply imitating • In this case, what they produce something that is not in their input. My teacher holded the baby rabbits.

17. Acquiring Morphology • Children sometimes make mistakes. • Why do they make errors like these? • 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) My teacher holded the baby rabbits.

18. Acquiring Morphology • Examples: • Horton heared a Who • I finded Renée • The alligator goed kerplunk • The case of verb past tense: • Regular verb forms require no stored knowledge of the past tense form (wug test) • Past tense is accomplished by applying a past tense rule (e.g., add -ed) to the verb stem • With irregular verbs something must be memorized

19. Acquiring Morphology • Stages in the acquisition of irregular inflections • The case of verb past tense: • 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: • Past tense is -t when attached to leave, keep, etc. • Is -> was • Dig -> dug • Has -> had

20. Acquiring Morphology • Stages in the acquisition of irregular inflections time • 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

21. Memory & Rules • Why do we find this type of pattern? • Memory and rules • The use of overregularized forms starts at around the same that that the child is beginning to apply the default -ed rule successfully • 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)

22. Memory & Rules • Why do we find this type of pattern? • Memory and rules • Other accounts • Maratsos (2000) – frequency explanation • It is possible to predict which verbs will be subject to overregularization • 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 • Something about irregulars is unpredictable, hence has to be memorized

23. What kind of “teaching” do kids get? • If language is learned (and not innate), how do kids do it? • What kind of feedback do they get? • Claim: Positive evidence is not sufficient for learning a language.

24. What kind of “teaching” do kids get? • Are the kids even aware of mistakes? • The children are apparently aware of the fact that their forms are strange: • 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

25. Positive and negative evidence • Positive evidence: Kids hear grammatical sentences • Negative evidence: information that a given sentence is ungrammatical • Kids are not told which sentences are ungrammatical(no negativeevidence) • Let’s consider no negative evidence further… • What kind of feedback is available for learning?

26. What kind of “teaching” do kids get? • How much Positive Evidence is there? • Estimated 5000 – 7000 utterances a day • Between ¼ and 1/3 are questions • Over 20% are not “full” adult sentences (typically Noun or prepositional phrases) • Only about 15% have typical English SVO form • Roughly 45% of all maternal utterances began with one of 17 words (e.g., “what”, “that”, “it”, “you”) Cameron-Faulkner, et al (2003) • So what kids do hear may be somewhat limited.

27. Negative evidence • Negative evidence could come in various conceivable forms. • “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

28. Kids resist instruction… McNeill (1966) • Child: Nobody don’t like me. • Adult: No, say ‘nobody likes me.’ • Child: Nobody don’t like me. [repeats eight times] • Adult: No, now listen carefully; say ‘nobody likes me.’ • Child: Oh! Nobody don’t likes me.

29. Kids resist instruction… Cazden (1972) (observation attributed to Jean Berko Gleason) • 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

30. Negative evidence via feedback? • Do kids get “implicit” negative evidence? • Do adults understand grammatical sentences and not understand ungrammatical ones? • Do adults respond positively to grammatical sentences and negatively to ungrammatical ones?

31. 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 • Adults understood 42% of the grammatical sentences. • Adults understood 47% of the ungrammatical ones. • Adults expressed approval after 45% of thegrammatical sentences. • Adults expressed approval after 45% of the ungrammatical sentences. Suggests that there isn’t a lot of good negative evidence.

32. In a way, it’s moot anyway… • One of the striking things about child language is how few errors they actually make. • 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. • But this isn’t the only view. There is an ongoing 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

33. Critical (sensitive) periods

34. Critical (sensitive) periods • Certain behavior is developed more quickly within a critical period than outside of it. This period is biologically determined. • Examples: • Imprinting in ducks (Lorenz, ; Hess, 1973) • 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 • 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

35. Critical (sensitive) periods • Certain behavior is developed more quickly within a critical period than outside of it. This period is biologically determined. • Some environmental input is necessary for normal development, but biology determines when the organism is responsive to that input. • That “when” is the critical period

36. Critical period for language • Lenneberg (1967) proposed that there is a critical period for human language • It assumes that language acquisition must occur before the end of the critical period • Estimates range from 5 years up to onset of puberty

37. Evidence for critical period for language • Feral Children • 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 • Victor, the Wild Boy of Aveyron • Genie

38. Victor, The Wild Boy of Aveyron • Found in 1800 near the outskirts of Aveyron, France • 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. • Described by Itard as “an almost normal boy who could not speak”

39. Genie • Found in Arcadia, California in 1970, was not exposed to human language until age 13.5. • Raised in isolation a situation of extreme abuse • Genie could barely walk and could not talk when found • Dr. Susan Curtiss made great efforts to teach her language, and she did learn how to talk, but her grammar never fully developed. • Only capable of producing telegraphic utterances (e.g. Mike paint or Applesauce buy store) • Used few closed-class morphemes and function words • Speech sounded like that of a 2-year-old

40. Genie • By age of 17 (after 4 years of extensive training) • Vocabulary of a 5 year old • Poor syntax (telegraphic speech mostly) • Examples • Mama wash hair in sink • At school scratch face • I want Curtiss play piano • Like go ride yellow school bus • Father take piece wood. Hit. Cry.

41. What Do These Cases Tell Us? • Suggestive of the position that there is a critical period for first language learning • 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 • Genie stopped talking after age 30 and was institutionalized shortly afterward (Rymer, 1993)

42. Effects of the Critical Period • Learning a language; • 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

43. Effects of the Critical Period • Learning a new language • What if we already know one language, but want to learn another?

44. Effects of the Critical Period • Johnson and Newport (1989) • Native Chinese/Korean speakers moving to US • Task: Listen to sentences and judge whether grammatically correct