Infant Development: The Object Concept PDF

PY40008 & PY50408 INFANT DEVELOPMENT Development of The Object Concept  Main Topics Today  Piaget’s theory  Baillargeon’s theory  Violation of expectation methods  Early studies on object permanence, solidity and continuity  Gradual acquisition...

PY40008 & PY50408 INFANT DEVELOPMENT Development of The Object Concept  Main Topics Today  Piaget’s theory  Baillargeon’s theory  Violation of expectation methods  Early studies on object permanence, solidity and continuity  Gradual acquisition of physical knowledge  Support  Development of event categories  Piaget’s Theory “The object is a mere image that re-enters the void as soon as it vanishes, and emerges from it for no objective reason" Piaget, 1955, The Child’s Construction of Reality  Piaget Claimed Young Infants Lack Symbolic Representations  An object does not exist independently of action (sensory motor concept of permanence)  An object is part of an action  Object properties are discovered through action  Infants lack mental representations – they cannot think about an object or its properties when it disappears from view Piaget, 1955, Construction of Reality  Piaget Claimed Young Infants Lack Symbolic Representations  Ability to form symbolic representations develops at the end of infancy (18 months)  This is shown by  Solving novel problems by planning  Delayed imitation  Recall memory  Inferring the movements of hidden objects  But all these abilities appear much earlier in the first year Piaget, 1955, Construction of Reality  Development of Manual Search  Development of object permanence is revealed by changes in manual search  Up to 8 months: no intentional search  8 - 12 months: intentional search, but return to the place where the object was last found  A not-B error  Object is created by the action of lifting the cover  12 - 18 months: return to the place where the object was last seen  After 18 months – search after an invisible hiding  Evidence for mental representation  Infants make inferences and engage in physical reasoning about occluded events Piaget, 1955, Construction of Reality  The A Not-B Search Error Correct search on A trial Error on B trial Video of the A Not-B Error on My Dundee  Piaget’s Theory – Reasoning About Occluded Events  Invisible hiding task  Occluded object is secretly hidden  Infants only search when they can mentally represent it’s invisible movement (after 18 months)  Cover transposition task  Object hidden under cover A  Positions of covers A and B are swapped  Infants search correctly after 18 months  Development of Physical Knowledge - Baillargeon’s Theory Three Adult Assumptions About Occlusion Events  Objects continue to exist  Objects retain their spatial and physical properties  Objects remain subject to physical law “Young infants’ understanding of occlusion events is strikingly similar to that of adults” Baillargeon, 1993, Chapter Baillargeon Claims That Infants Do Have Representations of Hidden Objects  Representations can include information about:  Object existence  Spatial position  Object properties  Object movement  The information in representations changes as infants get older  But see Wang & Onishi, 2017 for an alternative  Infants make inferences and engage in physical reasoning about occluded events Baillargeon, 1993, Chapter  Violation-of-Expectation Paradigm  Observation of visual events, so we can study infants who are too young to manipulate objects  May involve an initial event to familiarise infant with the procedure and materials  Initial event may also provide key information  In some studies infants are habituated to the initial event Baillargeon, 1993, Chapter  Violation-of-Expectation Paradigm  Test events  Physically possible  Physically impossible  Longer looking at the impossible event indicates  Understanding of the physical principle  Physical reasoning  Mental representation if the event was hidden from view (object permanence) Baillargeon, 1993, Chapter  Three Waves of Studies  First Wave – The Competent Infant  Infants form representations of hidden objects  Infants have expectations about a range of different physical events  VoE methods - look longer at unexpected events because they are surprised Baillargeon et al., 2010 Chapter The Ramp Study Baillargeon, 1986, Cognition, 23, 21-41 The Ramp Study - Results Longer looking at the impossible event suggests that 6m infants understood:  The box continued to exist in its same location when occluded  The car continued to exist and followed same trajectory  The car could not pass through the space occupied by the box Baillargeon, 1986, Cognition, 23, 21-41  Solidity & Continuity Are Understood at 3 Months Habituation Consistent Inconsistent Hand holds ball above screen and then drops it Spelke et al, 1992, Psych Rev, 99, 605-632  Control Events Habituation Test A Test B A hand places the ball before screen appears Spelke et al, 1992, Psych Rev, 99, 605-632  Knowledge of Solidity And Continuity Are Present At 3 Months Longer looking at inconsistent event Equal looking at control events Spelke et al, 1992, Psych Rev, 99, 605-632  Knowledge of Solidity And Continuity Is Present At 2 Months Habituation to a consistent event Spelke et al, 1992, Psych Rev, 99, 605-632  Knowledge of Solidity And Continuity Is Present At 2 Months Consistent Test Event Spelke et al, 1992, Psych Rev, 99, 605-632  Knowledge of Solidity And Continuity Is Present At 2 Months Inconsistent Test Event Spelke et al, 1992, Psych Rev, 99, 605-632  Inconsistent Event Again Violates Two Principles  Solidity  Two solid objects cannot occupy the same space  Continuity  An object traces exactly one connected path over space and time  Control Events Hand places object in final position so that all outcomes are possible (no violations) Spelke et al, 1992, Psych Rev, 99, 605-632  Two-Month-Old Infants Looked Longer At The Inconsistent Event p