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Class 6. Read Berk Ch. 6: Infant & Toddler Cognition How do babies think? Piaget’s theory of sensori-motor stages Information Processing Early language Stages Test 1 results. How babies think . Key Points: How infants understand & learn about the world from a Piagetian perspective
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Class 6 Read Berk Ch. 6: Infant & Toddler Cognition • How do babies think? • Piaget’s theory of sensori-motor stages • Information Processing • Early language • Stages • Test 1 results Class 6 2006
How babies think Key Points: • How infants understand & learn about the world from a Piagetian perspective • Object Permanence studies • Infants understand more than they show us Class 6 2006
Cognition Defined Three levels: macroscopic to microscopic: • 1. Organized series of cognitive actions • 2. Specific thoughts, language, learning abilities, & problem solving • 3. Mental processes that underlie those • Attention, • memory, • processing speed, • inhibitory ability Class 6 2006
Studying Infants • Infants • not able to say what they’re thinking • not good at follow instructions • nor do they have great motor skills • Assessing infant cognition requires creative experiments Class 6 2006
Why Piaget? • Broad & comprehensive theory • infant behaviours • Starting point for other developmental theories • Help you understand other infant cognition theories Class 6 2006
Piaget’s Theory Piaget’s primary goal was to • understand how infants & children develop ways of knowing & acquiring knowledge Key Parts • What are cognitive knowledge structures • How do cognitive structures change Class 6 2006
Piaget: Cognitive Structures Infants in 1st Year: start with reflexes • a perceptual & physical approach to world • sucking anything • looking & grasping objects • shaking or banging objects • dropping objects over-and-over • done with fascination & pleasure Class 6 2006
Piaget’s Cognitive Structures • What they are in infancy: • thoughts, strategies, & action patterns • Called schemas • What they do: • Determine the ways infants relate to, interact with, & understand the world Class 6 2006
Piaget’s Cognitive Structures • Infant Schemas • Use mouthing, grasping, & looking to explore • start simply -> more complex • start separately -> more coordinated In older children: • Cognitive structures are called operations Class 6 2006
How do cognitive structures change or develop? In Piaget’s theory schemas change when: • 1. Infants re-organize existing schemas • to integrate, coordinate, & combine schemas • Eg, 2 simple schemas -> one complex schema • eg, grasp or suck -> grasp & suck • eg, look or touch -> look & touch Class 6 2006
How do cognitive structures change or develop? • 2. Infants adapt to new experiences: • Assimilate: • fit new experience into current cognitive structure (existing knowledge) • Accommodate: • change the current cognitive structure to fit with new experience Class 6 2006
To Assimilate or to Accommodate? ‘Suck All Things’ Schema: Example • New plastic cat arrives • Sucking works fine -> ? • Start Drinking from a Cup • I’m getting all wet & still thirsty -> ? Advice: • Assimilate if you can, • Accommodate if you must (J. Block) Class 6 2006
Benefits of Change • Re-organization & Adaptation • leads to cognitive growth & improved function • more organized, accurate representation of reality Class 6 2006
Sensorimotor Stages Class 6 2006
Piaget’s Sensorimotor Stage • Piaget saw infants as scientists • actively engage environment to understand it • use intentional behaviour (means-end activity) as foundation of all problem-solving Class 6 2006
Key task of infants in Piaget’s sensorimotor stage? • to form mental representations or schemas using senses & motor activities by age 2 yr. • evidence of development of mental thought is • infant’s ability to understand that objects exist • even when they can’t be seen. • Called Infant Object Permanence Class 6 2006
Object Permanence • Do infants know that objects (or moms) exist even when they can’t see them? • Out of sight, out of mind? • Piaget believed that when infants ‘know’ objects continue to exist they have achieved object permanence Class 6 2006
Piaget’s Object Permanence • Understand that objects continue to exist even when out of sight. • develops 8 – 12 months. • Same time as intentional, goal-directed actions, • Imitation, • use both hands for same actions • Incomplete at first: A-not-B Error Class 6 2006
Infant Object Permanence Piaget’s test: A-not-B error • Show a toy to infant, • show-and-hide toy in 1 place - infant watches, • show and hide toy in 2nd place - infant watches • let infant reach for object in new hiding spot Does the infant ‘remember’ where toy is? • you switch locations, what does the infant do? Class 6 2006
Object Permanence: A-not-B Error (L. Camras website) A-not-B error led Piaget to notion that infants do not have a firm grasp of object permanence until about 18 months of age. Class 6 2006
A-not-B error findings questioned • Does object permanence really take so long? • Can they do it earlier? • With different tasks… • Vary the delays - between Hiding & Reaching • Vary # of A trials (practice) - before switching to B • Assess length of time - spent searching Class 6 2006
Object Permanence cont’d Vary the delays: • Vary delay between Hide & Reach • Longer delays produce more A-not-B errors • Young infants need less delay to show error • Older infants need more delay to show error • Interpretation: • May not be object permanence problem • May be evidence of a memory problem Class 6 2006
Object Permanence cont’d Just a habit? (Marcovitch, Zelazo, & Schmuckler, 2002) • Is A-not-B error just a habitual reaching error? • Varied # of A trials before switching to B • 3 groups: 1 A-trial, 6 A-trials, or 11 A-trials • Results: 6 A-trials: had most A-not-B errors • Conclusion: other cognitive activity going on • Some habitual reaching (6 trials > 1 trial), • But not just habitual reaching problem • By 11 trials - more understanding of task Class 6 2006
Object Permanence cont’d • New A-not-B study(Ruffman et al., 2005) • 61 infants, 8 – 12 months of age • Measured length of time infants spent searching • Why would infant search if toy no longer exists? • Results: infants search longer at A after B switch • Conclusion: infants believe object is at A • Object location problem - • Check wrong place, but toy still exists • not simply memory, attention, or motor inhibition problems • & not an object permanence failure Class 6 2006
A-not-B errors What have we learned? • Infants: • have greater memory capacity with age • form habits easily, but then can’t inhibit • learn from repeated experience • have unusual cognitive beliefs & expectations Class 6 2006
Apply to Real World… Infants • Form habits easily: use to your advantage • Regular bath time, feeding time, etc • Learn via sensori-motor experience: • let them explore the world • Actively trying things best • Cognitive beliefs may be unusual • Don’t assume that an infant interprets the world the same as us • They see things differently, and we need to adjust. • They might be scared, bored, fascinated Class 6 2006
Piaget’s Contribution • Broad & Comprehensive Theory • how we think about infant cognition • infants active explorers of their world • Basis many modern infant cognitive studies Class 6 2006
Piaget’s Cognitive Stages: • How infants relate, interact, understand the world: • qualitative stages • sequential & invariant developmental order • across all domains at the same time • eg, understand that object permanence applies to all people & objects at same time • eg, knowledge should be consistent across all sensorimotor modalities (touch, vision etc) Class 6 2006
Some Problems with Piaget • Recent refined studies do not support his Stage view • Studies show evidence of: • Continuous development (vs stages) • Older are better than younger • Different Developmental pathways (vs invariant) • Individual differences in infant responses • Domain specific (vs all domains) • Do not learn new skills in all areas at once Class 6 2006
Information Processing Perspective • Basic cognitive structure similar through life. • What changes is capacity of processing • Increasing speed & amount of information • more complex thinking possible with age. • Improvements in capacity due to • Brain development & better strategies • ie attention, memory, & strategies gets better Class 6 2006
Information Processing • Infant memory • Habituation studies • Show that infants can remember • 3-mo olds can remember visual stimuli for 1 day • 1-yr olds for several days • Better memory when they actively manipulate • But, not clear what they will remember Class 6 2006
Visual Expectation Paradigm • present infant with 1 stimulus repeatedly until they habituate • reduce their visual attention (viewing time) • then switch to a novel stimulus • ie, a distraction task • Does greater visual attention return? • ie Dishabituation to new unexpected event Class 6 2006
Habituation Display Class 6 2006
Test 1: Possible Event Class 6 2006
Test 2: Impossible Event Class 6 2006
Results • 6-month-olds look longer at impossible events. • Why? • Something unexpected happened • Car should not have come through block • Why is this evidence of object permanence? • Young infants understand that objects continue to exist even after being hidden behind a screen. Class 6 2006
Object permanence begin to develop by 3 to 4 months • Baillargeon (1987, 1991): Impossible event paradigm • Habituation trials Class 6 2006
Baillargeon (1987, 1991): Impossible event paradigm • Test trials Class 6 2006
Results • 3-4 mo infants looked longer at impossible events • was carrot top expected? • So unexpected, novel events -> Dishabituation • Why is this evidence of object permanence? • Carrot continues to exist even as it moves behind screen. Class 6 2006
Visual Expectation Results • Object permanence can explain longer looking times • as early as 3 - 4 mo, & well before 18 mo Two points: • Infants likely recognize & understand more than their behaviours show • Important to use the right measure Class 6 2006
Infant Language Stages of Language Development • Prelinguistic period - crying, smiling, fussing • communicative, but not language • Joint attention • Give- and -take • Preverbal gestures • Language-like sounds period • Linguistic period Class 6 2006
Stages of Language Development • First language-like sounds: • Phonation – birth to 2 mo • “Comfort sounds” • Cooing – 2 – 4 mo – cooing, • quasi-vowels, precursors of consonants Class 6 2006
Stages of Language Development Language-like sounds: • Expansion – 4 – 7 mo – cooing differentiated • New sounds – yells, whispers, growls, squeals • Fully formed vowels • Babbling begins - da Class 6 2006
Stages of Language Development Language-like sounds: • Cononical Stage – 7 – 10 mo • Increase in babbling • Consonant & vowels sounds • Duplicated babbling – da-da-da • Intonations imitating sound of real speech Class 6 2006
Stages of Language Development Language-like sounds: • Contraction Stage – 10 – 14 mo • Initial broad range of babbling sounds disappears • Only sounds found in mother-tongue remain Class 6 2006
Linguistic period General Principles • Comprehension precedes production of speech • Maturation important - stages are universal • Begin to understand words middle of 1st yr • Say first word at 10 – 17 mo (avg: 13.6 mo) • But also are cultural differences: • In English, 1st words are – usually referential • Refer to objects or people, not verbs or adjectives • In other languages (eg Chinese, Korean) • Verbs are preferred first Class 6 2006
Linguistic period One-word stage – just after 1st birthday • Individual words, no sentences • Words may mean something different to child • Overextension – may over-generalize word meanings • Eg all 4-legged animals are “horseys” • Underextension – may use words in too specific ways • ie under-generalize word meanings • Eg, “bear” refers to one toy, not other “bears” Class 6 2006
Linguistic period First Sentences: in middle of 2nd year • May be single words, but imply a statement • ie holophrases • Eg “Me,” meaning “I want to do it.” • Two-word stage: 18 – 20 mo • Universal phenomenon • Child can now use descriptive language: • Eg, naming (that house) • Possessive (my book) • Actions (kitty go) • Questions (where ball?) Class 6 2006
3 Theories of Language Development • Infants are taught • Behaviourist (Skinner) • Babies learn through operant conditioning • ie reinforcement and imitation • Infants teach themselves • Nativist (Chomsky) • Language too complex to learn by conditioning • Biologically primed • * Interaction of both in social context* • Children observe & participate in social exchanges • Communication vital • Nature likely provides many pathways to the goal Class 6 2006
Ways to Support Early Language Learning Class 6 2006