PSY2001 Lecture 5 - The Object Concept

Object permanence

Objects continue to exist even when they are out of sight

• Retains its spatial & physical properties

• Is still subject to physical laws

Role of mental representation

• Planning

• Deferred imitation

Piaget’s sensorimotor stage

0-24 months

• Learns about world through actions and sensory information

• Learns to differentiate self from the environment

• Understand causality, and form internal mental representations

  • 12 months: object permanence attained

  • By 18-24 months full internal representations

Sensorimotor substages - Reflex activity

Stage 1 (0-1 months)

• Practice innate reflexes (ex: sucking, looking)

Sensorimotor substages - Primary circular reactions

Stage 2. (1-4 months)

• Simple behaviours derived from basic reflexes

  • Start repeating behaviour (ex: thumb sucking)

• Focused on body

  • No differentiation between self and outside world

Sensorimotor substages - Secondary circular reactions

Stage 3. (4-10 months)

• Own behaviours, not reflexes

• Start to focus on objects

• Establish connection between body movement and external environment

Sensorimotor substages - Coordination of secondary circular reactions

Stage 4. (10-12 months)

• Engage with objects using a variety of actions

• Combine actions to achieve goals and solve novel problems

  • Some evidence of means-ends behaviour

  • Driven by trial-and-error

    • Limited by existing repertoire of actions

    • Lack flexibility

• A-not-B errors until 12 months

  • egocentrism

A not B error

• Infant continues to search for an object in a location where it was previously found, even though it has been moved to a new location.

• Lack of object permanence

Sensorimotor substages - Tertiary circular reactions

Stage 5. (12-18 months)

• Still repetitive or circular behaviours

• Discover the properties of objects and the environment

  • Understand objects through trial-and-error

  • Not yet inventive or insightful

• Improvements in problem-solving

  • Experiment with new actions, modify unsuccessful actions

• Still lack internal representations

Sensorimotor substage - Internal Representation

Stage 6. (18-24 months)

• Now has mental representation of the world

  • Can think and plan actions

  • Deferred imitation

• Solve novel problems insightfully

Piaget and development of object permanence

• Begin to search for objects around 8-9 months

• A not B error until 12 months

Piaget and development of planning

• Not until stage 6

• Ex: Lucienne versus Jacqueline and chain/box problem

Piaget and development of deferred imitation

• Copying behaviour after a delay

• Not until stage 6

Methodological critiques of Piaget

Observational methods, often with own children

• Quantitative, experimental data rare

• “Clinical method” rather than standardized

Confounding variables in Piaget’s work

• Motor coordination and motor planning deficits

  • Inability to perform coordinated actions (means-end)

• Memory deficits

• Communication – biased by cues

A not B error - Butterworth (1977)

• 3 conditions

  • Normal design (object permanence)

  • Covered but visible (other cog. processes)

  • Visible and uncovered (other cog. processes)

• Errors in all 3 conditions, even when object covered but visible

Reflects lack of coordination, not necessarily lack of object permanence

A-not-B error - Smith & Thelen (2003)

• One variation had infant stand instead of sit during “B” trial

  • 10m old infants performed like 12m old

• Standing made the “A” position less salient

A-not-B error - Bower and Wishart (1972)

Methodological changes: darkness rather than occlusion by other objects (visual vs manual search)

• Shown object within reach, lights turned off

  • Infants as young as 5m will grasp for out of sight objects

Piaget underestimated age of object permanence

• BUT still just performing “reaching action” (extension of ongoing action or reproduction of previous action?)

Violation of Expectation - Bower (1982)

• Infants a few months old, shown object, screen covered the uncovered object.

• 2 conditions: Object still in place versus empty space

• Monitored child’s heart rate

• Faster heart rate (more surprise) in second (empty) condition

Baillargeon et al (1985)

Drawbridge and Solid Box

• Suprise = look longer at impossible event

  • Experimental condition (box behind the drawbridge)

  • Control (box next to the drawbridge)

• Experimental condition looked longer at impossible event

Infants as young as 5 show object permanence, Piaget’s results were due to interaction of other cognitive abilities.

Baillargeon (2004)

From early age infants “interpret physical events in accord with general principles of continuity and solidity”

• As young as 2.5 months

• These principles are innate or babies born with ability to acquire knowledge about object properties very quickly

Criticisms of the VOE approach

• Indicates limited awareness of events (i.e. perceives a difference)

• Perceptual preference for novelty, but not understanding

• Depends on overall looking time versus social looking

• Do looking preferences really tell us about what babies know? (see Schöner and Thelen, 2006)

Planning - Clifton et al. (1991)

Presented 6m olds with small (required 1 hand grasp) and large (2 hand grasp) objects

• Each object made identifying sound

• Infants made appropriate grip to reach for objects in darkness

• Authors conclude this is based on mental representations

Planning - Claxton et al. (2003)

Differences in motor patterns in adults for planned actions (Marteniuk et al., 1987)

• Precise actions = slower approach

10m infants encouraged to throw ball or fit it into a hole

• If motor patterns determined by ball properties, should find no difference

• If determined by upcoming action, should find a difference

  • Reaching action slower for precise action

Planning - Willatts (1989)

9 months

• Toy out of reach on a cloth

• Cloth and toy blocked by a barrier

• Performed sequence of actions to get toy

Many on the 1st attempt

• Novel, planned actions

• Mental representation of the world used to organise behaviour

Deferred imitation - Meltzoff & Moore (1994)

6 weeks old

• Some infants saw adult make facial gesture, some saw neutral expression

• Day later, those who saw gesture were more likely to perform it

Retention of deferred imitation - Meltzoff (1995)

14m- & 16m-olds

• Experimenter performed series of actions with objects

• Both ages more likely to reproduce observed actions than those who did not see them

  • Even after a four month delay

Deferred imitation - Barr et al. (1996)

Infants saw series of actions with puppet and had to repeat after a 24hr delay

• 3 repetition condition: 6 mo no different to control (supports Piaget)

• 6 repetition condition: 6 mo score significantly higher than control

Context in deferred imitation - Patel et al. (2013)

6m, 9m, 24m tested using puppet paradigm, 24hr delay

• Varied the context during retrieval (auditory and visual)

• Full flexibility/generalization not achieved until 12m

Mechanisms that occur earlier than Piaget predicted

• Basic object permanence

• Planning

• Deferred Imitation