Psy1302 Psychology of Language

1. Psy1302 Psychology of Language Language Acquisition II Lecture 18

2. Reading Assignment Fisher & Gleitman (2002) • I. Outline of the task of language learning • 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 • Primitive Categories of Experience • Compositional Meaning • Interactions between linguistic and conceptual categories • IV. Forms to meaning • Mapping problem • Concrete words first • Old words make new words easier to learn • V. Where learning ends

3. 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) What does “tokibu gikoba gopila tipolu” mean anyway?

4. 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 Elephant! Artist: Henry Gleitman Learning by Association

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

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

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

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

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

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

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

12. Learning by AssociationPROBLEMS 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 AssociationPROBLEMS 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… • How do children ever learn the mappings between form and meanings?

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

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

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 • 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 • Social cues • Linguistic cues • 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) • Less limited: assume that there are no synonyms (E. Clark)

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

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

25. Mutual Exclusivity in Action • 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 • Child is NOT attempting to map a word to something in the world • 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!

27. Joint Reference • Joint Reference: when speaker and listener both interpret a phrase as referring to the same thing • 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 2 2 1 1 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. Linguistic Context Children make use of the linguistic context in which words appear Verb vs. nouns Mass nouns (e.g. sand) Count nouns (e.g., dog)

30. $#>@)(!&%

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

32. Using Linguistic Context Look, a seb! 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 • Don’t understand many words • Don’t understand much about syntax • Shared physical context must be key • 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

36. Some Milestones in Language Development AgeLanguage Development 1-2 months Cooing (oh, ah) 6 months Babbling (ba) 8 months Reduplicated Babbling (bababababa) 10 months Variegated Babbling (badago) 1 year First words (mummy) Repeating sound sequences 1-1.5 years One word stage (3-50 words) 2 years Two-word or Telegraphic stage 2-2.5 years Word Spurt 3 years Intelligible to strangers Receptive vocabulary: 1200-2000 words 4 years Speak grammatically 6 years Receptive vocabulary: 14,000 words

37. What caused the rapid vocabulary development? • Conceptual Development? • 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 60 Common Nouns 50 40 Percent of Total Vocabulary 30 Predicates 20 Close Class 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? • 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. Subject’s Task: Identify the “mystery word” represented by the beep. watch clip #1 Guess word. watch clip #2 Guess word again. watch clip #3 Guess word again. watch clip #4 Guess word again. watch clip #5 Guess word again. watch clip #6 Guess word again. Final Guess On to Next Mystery Word

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

43. Why nouns differ from verbs in ease of acquisition • Nouns typically name objects and Verbs typically name events • Objects persist, events typically do not • 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. BLOC Non-BLOC e.g. dog e.g. throw e.g. thing e.g. think Dividing words up intoConcretenessCategories English Experiment -- Snedeker, Gleitman, and Brent (1999) * BLOC = Basic Level Object Category 45% 40% Noun * Observable Verb 35% Unobservable 24 Nouns 30% 25% Percentage of Correct Identification 20% 24 Verbs 15% 10% 5% 0% 24 Nounsvs.24 Verbs 12 BLOCs vs. 12 Non-BLOCs (Nouns) 13 Observables vs. 11 Unobservable (Verbs)

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

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

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

50. 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 Scenes Nouns Frames Scenes + Nouns Scenes + Frames Nouns + Frames Scenes + Nouns + Frames Snedeker & Gleitman (2002)