Breaking the Word Learning Barrier: How children learn their first words

1. Breaking the Word Learning Barrier:How children learn their first words Kathy Hirsh-Pasek Roberta Golinkoff Beth Hennon Mandy Maguire

2. Outline • I. The Word Learning Problem • II. Three Theories of Lexical Acquisition • III. The Emergentist Coalition Model • IV. Evidence for the Theory • V. Conclusions

3. Part I The Word Learning Problem

4. Introduction to Word Learning At twelve months, David utters his first word. In just seven or eight months, he will be learning up to nine new words a day and will have over 50 words in his productive vocabulary.

5. Two questions • 1. How do infants break the word barrier at ~ 12 months? • 2. What accounts for the changing character of word learning that appears at ~ 19 months?

6. Breaking the Word Barrier • Segment words from the constant flow of speech (Jusczyk, Cutler, & others). • Find coherent objects, actions, and events in their environment (Spelke, Baillargeon, & others). • Map the words to those objects and events in a symbolic way (Markman, Clark, Waxman, Tomesello, & others).

7. Quinean Conundrum • “Gavagai!”

8. Part II. Three theories of Word Learning

9. Constraints/Principles Views • Assumption: Takes Quine seriously. Child has a major induction problem. Child as biased word learner. • Data: Children entertain limited hypothesis for a word's meaning. • Markman's Mutual Exclusivity • Clark's Conventionality • Golinkoff, Mervis, & Hirsh-Pasek’s N3C

10. Constraints/Principles Views • “If we grant learners some domain-specific principles, we provide them with a way to define the range of relevant inputs, the ones that support learning about that domain. Because principles embody constraints on the kinds of input that can be processed as data that are relevant to that domain, they therefore can direct attention to those aspects of the environment that need to be selected and attended to (p. 130)” • Gelman & Greeno (1989)

11. First Tier Reference Words map to objects, actions, and events Object Scope Words map to whole objects Extendibility Words map to more than one exemplar Diagram of lexical principles framework

12. Associative Views • Assumption:Quine is irrelevant. Word learning develops from domain general associative learning mechanisms -- dumb attentional mechanisms. • Data: Children will make any link if it is salient. • Salient Objects • Salient Part. • Salient Actions

13. Associative Views • “…children do not acquire their first words rapidly rather fast word learning only occurs only after children have already learned some initial words [fast word learning] might be a learned generalization from language input.” • Smith (1996)

14. Social-Pragmatic • Assumption: Inverse of Quine. Social world guides child to word-world mapping. Child is Apprentice to Expert Word User. • Data: Children recognize social cues and use them in the service of word learning. • Baldwin's telephone example • Tomasello's joint attention: adults constrain conversation.

15. Social-Pragmatic “The typical way children acquire words...is almost completely opposite of the Quinean paradigm. Children do not try and guess what it is that the adult intends to refer to; rather...it is the adult who guesses what the child is focused on and then supplies the appropriate word (pp. 240-241)” Nelson (1988)

16. Problems with the theories • Snapshots • Reductionism • Single cues not multiple cues We need to avoid snapshots and find a system which embraces change.

17. The Battle Social Pragmatic VS. Constraints Associative Mutually exclusive or compatible?

18. Part I I I An Attempt at Integration

19. Emergentist Coalition Model We propose a hybrid-developmental model in which children start with basic word learning principles but the character of these principles changes over time. For example, children might start with a principle of reference -- that a word refers. At first, a word is ASSOCIATED with the most interesting object. Later, word reference is SOCIALLY informed, mapping onto the object the speaker has in mind.

20. Emergentist Model We propose a model of an active child which has the following properties: • Multiple Cues - Attentional, Social, Linguistic. • Differential Weighting over time • Emergent properties - Immature to Mature

21. Multiple Cues Perceptual Salience Temporal Contiguity Grammar Child Learner Eye Gaze Morphology Social Context

22. Differential Weighting: Time 1 Perceptual Salience Temporal Contiguity Grammar Child Learner Eye Gaze Morphology Social Context

23. Differential Weighting: Time 2 Perceptual Salience Temporal Contiguity Grammar Child Learner Eye Gaze Morphology Social Context

24. Differential Weighting: Time 3 Perceptual Salience Temporal Contiguity Grammar Child Learner Eye Gaze Morphology Social Context

25. Emergent: Immature to Mature Only from the combined action of multiple cues is word learning even possible. • Domain-general to specific • Own view to other’s view • Indexical (signal) to symbolic Principles are thus the products, not the engines of development.

26. Validating the Emergentist Model • Do children use multiple, overlapping cues in word learning? • Does the weighting change over time? • In this manner, are word learning principles emergent products?

27. Part IV: Evidence for the Emergentist Coalition Model The Principles of Reference and Extendibility as cases in point.

28. The Case of Reference

29. The Principle of Reference Considered by many to be the most basic of word learning principles, often considered to be a “conceptual primitive.” States that words symbolically “refer” to objects, actions, and events.

30. A Continuum of Reference • Immature principle of reference: • Domain-general associative behavior. • “Goes-with” relationship (telephone-->ring) • Perceptual Weighting: What kid has in mind. • Mature principle of reference: • Domain-specific rule-like behavior. • “Stands-for relationship” -- Non-iconic • (Word telephone used without phone present.) • Social Weighting: What adult has in mind.

31. Practical Consequences of a Continuum of Reference Immature Principle of Reference Attaches label to object, action, or event that is the most interesting in the environment -- perceptual cues dominate mapping. Often wrong! Mature Principle of Reference Social cues dominate mapping. Child becomes apprentice to adult for quick and reliable learning.

32. Hypothesis If present children with interesting and boring objects AND label the boring object (e.g.. Look at it, point to it, handle it)… Children with an immature principle: Assume the label maps to the interesting object regardless of what the adult does. Children with an mature principle: Assume the label maps to the boring object that the speaker has in mind.

33. Conditions

34. Need for a method. • A method that would allow for controlled word learning experiments in both 12 month old infants who are just learning their first words and in 24-month old word learning sophisticates. • A method that makes minimal demands on babies. • A tightly controlled procedure where word learning cues could be systematically introduced.

35. The Interactive IPLP Video Display Board Parent & Child

36. Display Board “Where’s the Ball.”

37. Display Board “Do you see the ball? Look at the Ball.”

38. Logic Children will allocate more attention to the object that “matches” the requested object.

39. Interactive IPLP: Design

40. Familiar Procedure

41. Novel Trial Procedure (Part 1)

42. Novel Trial Procedure (Part 2)

43. Conditions

44. Hypothesis Younger children would map words (associate words) to the most interesting object even in the conflict condition while older children will use social cues to map words to objects and will label the boring object if that is the object labeled by the experimenter.

45. Independent & Dependent Variables • Independent: - Age - Toy labeled - Side of match Dependent - visual fixation

46. 99 subjects; 33 at each of three ages - 12, 19, 24 mo. . Validation: Familiar Trials within paradigm assess whether children can do the task. Test of model: Novel Trials in which children are trained to map a label onto either an interesting or a boring unfamiliar toy. Study 1: Validation & Test of Model

47. Familiar Results Where infants able to do the task? YES!

48. Familiar Results: Mean Looking to Targeted Object Mean Looking time (sec)

49. Salience Results Was the interesting toy and boring toy really interesting and boring? YES!

50. Salience Results