1. Psy1302 Psychology of Language Language Acquisition II Lecture 18

2. Reading Assignment Fisher & Gleitman (2002) I. Outline of the task of language learning I. Outline of the task of language learning II. Where language learning begins II. Where language learning begins –Categorization of Speech Sounds –Segmentation of Spoken Word –Role of Sound in Syntactic Analysis –Distributional Analysis and Discovery of Syntax II. Meanings II. Meanings –Primitive Categories of Experience –Compositional Meaning –Interactions between linguistic and conceptual categories IV. Forms to meaning IV. Forms to meaning –Mapping problem –Concrete words first –Old words make new words easier to learn V. Where learning ends V. Where learning ends

3. What does “tokibu gikoba gopila tipolu mean anyway? What does “tokibu gikoba gopila tipolu” mean anyway? Mapping Form to Meaning To learn a language is, by definition, to acquire a set of pairings between sounds or more abstract linguistic structures and their meanings. Fisher & Gleitman (2002)

4. Artist: Henry Gleitman Elephant! Learning by Association John Locke, 1690 Book 3, IX, 9: If we will observe how children learn languages we shall find that.... people ordinarily show them the thing....and then repeat to them the name

5. You learn the meaning of elephant because whenever you hear “elephant” you see an elephant. You learn the meaning of elephant because whenever you hear “elephant” you see an elephant. Association is formed Association is formed Of course often you see other things as well... Of course often you see other things as well... Learning by Association

6. Gavagai! Unconstrained induction (or the radical indeterminacy of translation) Quine, 1960

7. What could “gavagai” mean? Rabbit? Mammal? Ears? Brown? Fluffy? Carrot eater? Scurrying Hopping Thumping Stay! What a cutie! Meal! Rabbit only until eaten! That’s not a dog! Chinchila rabbit? Animal? vegetarian? Long ears? Look!

8. Unconstrained induction RABBIT! RABBIT EAR and PAW RABBIT + FLOOR Sometimes I wonder too!

9. Learning by Association PROBLEMS 1. Relying on Association could be slow –Have to rule out many alternate hypotheses –Yet, children sometimes learn words in a single trial. “Give me the chromium tray, not the blue tray.” Fast Mapping Carey & Bartlett

10. Learning by Association PROBLEMS 2. Some meanings cannot be disentangled from situations GIVING RECEIVING VERBS PREPOSITIONS ABOVE BELOW

11. Learning by Association PROBLEMS 3. How do we learn words that do not refer to concrete objects? –“nap”, “hour” –mental states: e.g. “think”

12. Learning by Association PROBLEMS 4. We do not always see object or action at the same time as we hear the word. – “Where’s your mother?” – “Eat your peas” – OPENING action occurs only 1/3 of the times that “open” said

14. Learning by Association PROBLEMS 5. Does not necessarily explain how we learn to generalize word to new instances –An object can be categorized at many levels –And in many ways (by shape, size, texture, function)

15. Chairs http://en.wikipedia.org/wiki/List_of_chairs

16. Child sees only a few exemplars of dog....how does she learn to extend the word to all these different types of dogs?

17. Given all the above problems with the learning by association account… Given all the above problems with the learning by association account… How do children ever learn the mappings between form and meanings? How do children ever learn the mappings between form and meanings?

18. Successful comprehension of any intended linguistic expression cannot be achieved without some commonality of thought. Successful comprehension of any intended linguistic expression cannot be achieved without some commonality of thought. Language Learning

19. Language learning is possible because babies can organize categories in much the same ways as their adult caretakers do. Language learning is possible because babies can organize categories in much the same ways as their adult caretakers do. Language Learning

20. Child sees only a few exemplars of dog....how does she learn to extend the word to all these different types of dogs? Dogs Shmogs

21. Word Learning Children develop reasonable biases in how to interpret meanings of novel words Children develop reasonable biases in how to interpret meanings of novel words –Development of these biases may be influenced by naming practices of the target language being learned They draw on various sources of information in learning word meanings They draw on various sources of information in learning word meanings –Social cues –Linguistic cues State of the learner’s linguistic knowledge will dictate sources of information recruited State of the learner’s linguistic knowledge will dictate sources of information recruited

22. Word Learning Biases Mutual Exclusivity Assume that every object has just one name (E. Markman) Assume that every object has just one name (E. Markman) Less limited: assume that there are no synonyms (E. Clark) Less limited: assume that there are no synonyms (E. Clark)

23. Mutual Exclusivity in Action Experimenter “Look here’s a dax” Experimenter “Look here’s a dax”

24. Mutual Exclusivity in Action Child....that’s a telephone Child....that’s a telephone it can’t be a dax it can’t be a dax

25. Mutual Exclusivity in Action Child....so that other thing must be a dax! Child....so that other thing must be a dax! 18 months-olds can do this…

26. Social Perspective Word learning occurs in a social context Word learning occurs in a social context Child is NOT attempting to map a word to something in the world Child is NOT attempting to map a word to something in the world Child is attempting to discover another person’s intention to refer Child is attempting to discover another person’s intention to refer –Referent = the thing/event/action in the world that an instance of the word refers to –Meaning = the concept that is paired with a word Word learning is an attempt at mind reading! Word learning is an attempt at mind reading!

27. Joint Reference Joint Reference: when speaker and listener both interpret a phrase as referring to the same thing Joint Reference: when speaker and listener both interpret a phrase as referring to the same thing Achieved through joint attention based on Achieved through joint attention based on –Prior linguistic context –Shared goals or world knowledge –Visual attention to physical context

28. Baldwin (1991) Social Cue - Joint Reference 1 2 1 2 Follow-In: Mom looks at same thing. Disjoint: Mom looks at different thing. Mom then says: “Oh, look at the toma! See that toma? Wow, that’s a toma!” Child then asked to identify “toma”. 18 months-olds succeed at tracking where mom is looking and using that to determine what is the “toma.”

29. Children make use of the linguistic context in which words appear Verb vs. nouns Mass nouns (e.g. sand) Count nouns (e.g., dog) Linguistic Context

30. $#>@)(!&%

31. He’s sebbing! Brown, 1957 Using Linguistic Context

32. Look, a seb! Using Linguistic Context Brown, 1957

33. Using Linguistic Context Look, some seb! Brown, 1957

34. State of the learner’s linguistic knowledge and information recruited Initially, child has impoverished information about linguistic context and the structure of the world Initially, child has impoverished information about linguistic context and the structure of the world –Don’t understand many words –Don’t understand much about syntax Shared physical context must be key Shared physical context must be key Speakers attention can be inferred through: Speakers attention can be inferred through: –eye gaze –body orientation –gestures

35. Vocabulary growth By the age of 3 years, children have been learning about 8 new words a day By the age of 3 years, children have been learning about 8 new words a day

36. AgeLanguage Development 1-2 monthsCooing (oh, ah) 6 monthsBabbling (ba) 8 monthsReduplicated Babbling (bababababa) 10 monthsVariegated Babbling (badago) 1 yearFirst words (mummy) Repeating sound sequences 1-1.5 yearsOne word stage (3-50 words) 2 yearsTwo-word or Telegraphic stage 2-2.5 yearsWord Spurt 3 yearsIntelligible to strangers Receptive vocabulary: 1200-2000 words 4 yearsSpeak grammatically 6 yearsReceptive vocabulary: 14,000 words Some Milestones in Language Development

37. What caused the rapid vocabulary development? Conceptual Development? Conceptual Development? Changes in Representations of the Input? Changes in Representations of the Input? –What kinds of words are easily learned through observation? –What kinds of words rely on knowledge of words and syntax for learning?

38. Vocabulary Composition Common Nouns Predicates Close Class Percent of Total Vocabulary 60 50 40 30 20 10 0 # of Words in Vocabulary from Bates, E., Dale, P. S., & Thal, D. (1995).

39. Experiment: Limits of Observation Question: Which words are easier to learn from observation? Question: Which words are easier to learn from observation? To answer question: Gleitman & colleagues asked adult speakers who are “cognitively mature” to view SCENES of what mothers are saying to their children and see which words they could learn. To answer question: Gleitman & colleagues asked adult speakers who are “cognitively mature” to view SCENES of what mothers are saying to their children and see which words they could learn.

40. Experiment with English Speakers Snedeker, Gleitman, and Brent (1999) Stimuli preparation 1. Videotape English speaking mothers playing with their 18-24 month old children 2. Transcribe video tape for mothers’ 24 most frequent nouns and 24 most frequent verbs. 3. For each of the most frequent word, randomly select 6 uses of the word. 4. Edit each instance for 40 second clips. Audio was removed and a beep is sounded at instant word uttered.

41. Final Guess On to Next Mystery Word watch clip #6 watch clip #5 watch clip #4 watch clip #3 watch clip #2 watch clip #1 Subject’s Task: Identify the “mystery word” represented by the beep. Guess word. Guess word again.

42. Percent Correct Identification in English Snedeker, Gleitman, and Brent (1999) 0% 5% 10% 15% 20% 25% 30% 35% English Percentage of Correct Identification NounVerb

43. Why nouns differ from verbs in ease of acquisition Nouns typically name objects and Verbs typically name events Nouns typically name objects and Verbs typically name events Objects persist, events typically do not Objects persist, events typically do not Object concepts and event concepts are organized differently Object concepts and event concepts are organized differently –Hierarchies for objects –Dimensions for events –Leads to multiple salient categorizations for all event WITHIN a language (fewer for object)

44. Dividing words up into Concreteness Categories English Experiment -- Snedeker, Gleitman, and Brent (1999) * BLOC = Basic Level Object Category 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 24 Nouns vs. 24 Verbs12 BLOCs vs. 12 Non-BLOCs (Nouns) 13 Observables vs. 11 Unobservable (Verbs) Percentage of Correct Identification Noun Verb 24 Nouns 24 Verbs * BLOC Non-BLOC e.g. dog e.g. thing Observable Unobservable e.g. throw e.g. think

45. Proposal for Vocabulary Development 1. Scenes: –Child relies on situational context alone –Can learn only very concrete words: object labels

46. Proposal for Vocabulary Development 2. Nouns: –Object labels  richer representation of linguistic context – Utterance = set of known nouns –Child can learn concrete relational words spatial prepositions many verbs

47. Hear 3 nouns (man, apple, you) ….man…..GORP…apple….you Vs. Hear 2 nouns (man, apple) ….man…..GORP…apple How knowing some words will help learning…

48. Proposal for Vocabulary Development 3. Syntactic Frames: Learning relational words allows the child learn the basic grammar of her language Learning relational words allows the child learn the basic grammar of her language Utterance is represented as a syntactic structure + known words Utterance is represented as a syntactic structure + known words This representation allows the child to learn more abstract words This representation allows the child to learn more abstract words

49. Examples of words learned by 12 months (scenes): by 12 months (scenes): –mommy, bottle, telephone, cup, hi by 20 months (nouns): by 20 months (nouns): –go, sit, hug, hand, big, up 30+ months (frames): 30+ months (frames): –by, around, listen, think, other,

50. Snedeker & Gleitman (2002) Targets Targets –Videotaped interactions of 4 mother-child pairs –24 most common verbs chosen as targets –for each target 6 instances randomly selected Ss participated in one of 7 Information Conditions Ss participated in one of 7 Information Conditions –Scenes –Nouns –Frames –Scenes + Nouns –Scenes + Frames –Nouns + Frames –Scenes + Nouns + Frames

51. Scenes Condition Final Guess On to Next Mystery Verb Etc…. Task: Subjects guess mystery verb from watching 6 instances of word use in video clips. The video clips are silent except beeps replace the moments the mystery word were uttered. Example: “play” beep Guess Word. Guess Word Again.

52. Nouns Condition On to Next Mystery Verb Example: “play” Task: Subjects shown the nouns co-occurring with the mystery verb in 6 sentences, the same sentences as those in the video clips with the beeps. Guess Word. Guess Word Again. Final Guess 1. elephant, piano 2. mommy 3. I, it, you 4. it, you 5. drums 6. music, you

53. 1. Can kax SIRN the bussit? 2. Noggle SIRN? 3. Can po SIRN while lo nirp nu? 4. Lo are gonna SIRN nu? 5. SIRN the neps. 6. Lo SIRN tuggy wilm. Frames Condition On to Next Mystery Verb Example: “play” Task: Subjects guess the mystery verb from the 6 sentence frames. The sentence frames are constructed by replacing words in the 6 utterances with nonsense words. Guess Word. Guess Word Again. Final Guess

54. Correct Identification Varies with Information Condition Nouns Scenes Frames 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% % Correct on Final Trial p <.05

55. Correct Identification Varies with Information Condition Scenes Scenes+Nouns Full Info 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% % Correct on Final Trial p <.05

56. Correct Identification Varies with Information Condition Nouns Scenes + Nouns Frames Scenes + Frames Nouns + Frames Full Info 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% % Correct on Final Trial p <.05

57. Word Learning Children develop reasonable biases in how to interpret meanings of novel words Children develop reasonable biases in how to interpret meanings of novel words –Development of these biases may be influenced by naming practices of the target language being learned They draw on various sources of information in learning word meanings They draw on various sources of information in learning word meanings –Social cues –Linguistic cues State of the learner’s linguistic knowledge will dictate sources of information recruited State of the learner’s linguistic knowledge will dictate sources of information recruited