Cognitive Development

1. Cognitive Development • How do infants perceive the world? • Is the human face “special” in early perception ? • How do children acquire language? • What happens when a child has not been exposed to language?

2. Cognitive DevelopmentHow do infants perceive the world? • Basic sensory processes: • Vision • Hearing • Smell • Taste • Touch

4. Cognitive DevelopmentHow do infants perceive the world? • Basic sensory processes: • Vision • Hearing • Smell • Taste • Touch

5. Method: Preferential Viewing • Premise: • infants prefer novel stimuli over familiar stimuli • infants “pay attention” to novel stimuli • when stimulus becomes familiar, they pay less attention (i.e., they habituate)

6. Complex Perceptual Processes Object Perception • Edges – mark boundaries of objects • Ghim et al (1990) study – 3 month old infants

8. Perceptual Processes (cont’d) Size constancy Granrud (1986) study – 4-5 month olds “novel bear study”

9. Can infants perceive depth?Visual Cliff (Gibson & Walk, 1960)

10. Face perception: a special case?

11. Eye movements in face perception

12. Piaget’s Theory of Cognitive Development

13. Fundamental Assumptions: • Schemes – child as a ‘scientist’ • Intellectual adaptation involves: • Assimilation • Accommodation Equilibrium vs. disequilibrium

14. Piaget’s Stages of Development: • Sensorimotor – birth to 2 yrs. • reflexes become coordinated • thought and physical action are same • 18-24 mos. – start using symbols

15. Piaget’s Stages (cont’d) • Preoperational – 2 to 7 yrs. • use of symbols • imaginative play • egocentrism • conservation

16. Egocentrism

17. Conservation

18. Conservation (cont’d)

19. Piaget’s Stages (cont’d) • Concrete Operations – 7 to 12 yrs. • use mental operations to solve problems • 4+2=6 thus, 6-2=4 • operational schemas tied to real world: • If you hit a glass with a hammer, the glass will break • Don’t hit a glass with a hammer. • If you hit a glass with a feather, the glass will break. • Don’t hit a glass with a feather.

20. Piaget’s Stages (cont’d) • Formal Operations – adolescence on… • abstract thinking • hypothetically speculate • reason deductively

21. Evaluation of Piaget Pros: • empirically based • stimulated a lot of research! • used by parents and educators Cons: • underestimates younger preoperational child • overestimates adolescence and adults • Concepts are vague – new “information processing” approach • de-emphasized role of social environment

22. Language Development

23. Stages of Language Development • Perceiving speech phoneme – elementary vowel and consonant sounds “DOG” “LIGHT” • infants can distinguish between phonemes of different languages before 6 mos. – can’t after 6-8 mos.

24. Perceiving speech (cont’d) • How do infants perceive words? • stresses • repeated co-occurring patterns pa bi kugo la tada ro pi later, pa ro tu - “motherese”

25. Producing Speech • Cooing – 2 months “ooooooo” “ahhhhhhhh” • Babbling – 4-6 months “bah” “dah” “pah”

26. Producing Speech • First Words – by 1st birthday “Dada” “Mama” “go” • 18 mos. – 15-20 words • 2 yrs. – few hundred • 5 yrs. – 10,000 words “Fast Mapping” • Joint attention • Constraints on word names • Sentence cues

27. Naming Errors (1-3 yrs) • Underextension errors • Overextension errors

28. Producing Speech (cont’d) • Speaking in sentences • starts 18-24 mos. • “telegraphic” speech agent + action “Daddy eat” action + object “gimme cookie” agent + object “boy car” • by 2 ½ - more complex – learning “rules”

29. Berko (1958) study

30. Overgeneralization (~ 3 yrs) • exception or irregular words • “two fishes” • “two foots” • “I goed” Do parents correct grammar? Brown & Hanlon study – “truth value”

31. How do children learn language?

32. Skinner’s theory • learned through reinforcement and imitation • Any support? • Any problems? • ease and rapidity • staging is “universal” • produce more than they hear • not direct imitation of adult speech

33. Noam Chomskey • Language acquisition device (LAD) • Any support? - specific brain regions associated with language - only humans “readily” learn grammar - critical period for learning language (Lenneberg) case of “Genie”

34. Genie’s progression 0 whimpering • imitating single words; responding to speech of others • produce single words spontaneously • two word utterances • verbs and adjectives added • 3-4 word strings (subject verb object) • negative sentences • plurality of nouns, prepositions, possessives Missing: Question words, transformation rules, syntax, grammatical sequences “No more hurt” “Applesauce buy store”