The Cognitive Infant: Pt 1- Visual Cognition

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The Cognitive InfantPt 1- Visual Cognition

• Early Years Lecture 3

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• Reminder - Tutorial week 1/2 - reading is
• Bruner, J. S. Sherwood, A. V. (1976). Early
  Rule Structure The case of "peekaboo".
• Reprinted in Gauvain, M. Cole, M. (1997)
  (Eds.). Readings on the development of children
  (2nd edition). New York Freeman Co.
• (see Tutorial Solutions in Library)

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3 Theories of Cognitive Development

• This lecture - Gibsons ecological theory
• Next lecture - Piagets constructivist theory
• Later - Vygotskys socio-cultural theory

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This lecture

• Outline newborns physical state
• Methods for assessing cognition?

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The state of the newborn

• Little posture control muscular limitations
• 0 - 6 months lie prone
• 2 months head control emerging
• 6 months sit upright crawling
• 12 months walk-like behaviour

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The state of the newborn

• Set of reflexes (e.g.),
• knee-jerk (persists into adulthood)
• pupil reflex (to light also permanent)
• startle reflex (e.g., to loud noise)
• sucking (rhythmic - involuntary)
• stepping (disappears after 6-8 weeks)
• grasping (spontaneous for 3-4 months)

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The state of the newborn

• Absence of motor control other senses
  important for learning about the world
• Vision most important sense
• Q. What does infant visual perception offer in
  the way of learning?

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What does the infant know about the world?

• one blooming, buzzing confusion
• (James, 1890)
• Two important questions
• What do infants know about objects in the
  environment?
• What do infants know about other people?

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How to measure infant visual perception?

• Two dominant experimental techniques
• Spontaneous visual preference
• present two stimuli, side by side, measure
  looking time.
• Habituation
• looking declines over time. If discriminating,
  will look longer at new stimulus.

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How to measure infant visual perception?

• Spontaneous visual preference (Fantz, 1960s)
• Two visual stimuli
• left visual field right visual field
• Measure time spent looking L and R stimulus
• Infants typically spend longer on one
• Check by counterbalancing stimuli

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How to measure infant visual perception?

• Habituation
• Present stimulus 1 until infant is no longer
  interested in it (i.e., is habituated to it).
• Present new stimulus - if infant discriminates gt
  longer looking.

Stimulus 1
Stimulus 2
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How to measure infant visual perception?

• Habituation - Pt 2 (Habituation - novelty)
• Present stimulus 1 until infant is no longer
  interested in it (i.e., is habituated to it).
• Present old and new stimuli simultaneously.
• Controls for preference as well as
  discrimination.

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How to measure infant visual perception?

• Third measure - Heart rate
• Increased attention lowering of heart rate
• Therefore.
• Habituation (reduced attention) higher heart
  rate
• Also measures anxiety (but in opposite
  direction).

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Object knowledge

• Do babies perceive the environment as we do?
• Vision is the least developed sense at birth
• Retina lacks structure muscular limits on
  ability to focus
• (Banks Bennett, 1988)
• Impoverished visual acuity (Allen, 1978).
• Eye movements sluggish (Salivate Banks, 1978
  Aslin, 1981).

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Development of Object knowledge

• Pattern perception
• Infants prefer complex to simple patterns as
  long as their visual acuity can discriminate
  between them
• (Banks Salapatek, 1983).
• 1 month gt less complex array (8 squares)
• 2 months gt more complex (32 squares)
• (Fantz Fagan, 1975)

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Development of Object knowledge

• Figure perception
• 1 month gt single feature of figure (e.g., edge)
• 2 months gt central features of figure
• (Salapatek, 1975)
• By 2 months, infants developing exploratory
  behaviour when presented with visual stimuli
• becoming active in seeking out information.

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Problem of assessment?

• Q.
• How can we assess whether infants are able to
  make sense of what they see (how to get inside
  their heads)?
• e.g., are they able to integrate features of the
  environment?
• A. See if they can perceive something that
  doesnt actually exist (using habituation method)

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Development of Object knowledge

• Boundary perception
• 4 months gt perception of subjective boundaries

Ghim (1990) the search for structure.
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Development of Object knowledge

• Habituate to rectangle..... look longer at
  triangle

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Development of Object knowledge

• 1 week patterned gt plain shapes
• 1 month single feature gt multiple areas
• simple gt complex
• 2 months scan whole figure
• exploratory behaviour
• 3 months complex gt simple
• 4 months making sense of visual data

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What about other people?

• From last week....
• ....people key elements in infant lives
• gt face recognition has adaptive value

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Development of People knowledge

• Pattern recognition or face recognition?
• Newborn preference for face-like pattern
• (Johnson, 1999)

Disappears after 6 weeks
A gt B
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Development of People knowledge

• Pattern recognition or face recognition?
• Infants prefer real faces to jumbled faces.
• (E.g., Fantz, 1961 Maurer and Barrera, 1981)

A gt B gt C
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Development of People knowledge

• Problems - after 2 months
• A gt C preference for complexity?
• A gt B preference for symmetry?

A B C
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Development of People knowledge

• Newborn face-like arrays gt inverted faces
• 2 months real faces gt scrambled faces
• 3 months smiling gt frowning faces
• attractive gt unattractive faces
• Mums gt strangers face
• (Maurer, 1981 Samuels Ewy, 1985 Barrera
  Maurer, 1981)

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Development of People knowledge

• Newborns scan boundaries - but discriminate very
  simple face-like patterns.
• At 2 months explore internal features able to
  discriminate realistic from unnatural composition
  of features.
• By 3 months, begin to remember familiar faces and
  discriminate between different emotions.

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Developmental theory?

• Remember Poincarés concern about theory versus
  facts...
• ...so far, weve discussed the facts - the
  what?and when? issues, but havent integrated
  them into a theory that addresses why?

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Getting down to the So what

• What function (s) - if any - does a developing
  visual system serve
• Obvious!
• But why a preference for complexity?

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Why a preference for complexity?

• What function does it serve?
• Level of complexity matches the visual acuity of
  the developing system.
• Complexity stimulation.
• Linear Systems Analysis
• (Banks Ginsburg, 1985)

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Why a preference for complexity?

• In other words....
• ...limitations in the visual system mean that the
  brains processing ability isnt overwhelmed by
  too much information...
• ...visual system constrains cognitive system.

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What other function?

• Complexity drives the visual system
• Reduction in visual stimulation.....?

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Why a preference for complexity?

• Critical period? Kitten experiments.
• Lack of use defective vision
• (Weisel Hubel, 1963)
• Impoverished environment gt visual
  impoverishment
• (Blakemore Cooper, 1970)

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Blakemore Cooper (1970)

• Kittens reared in an environment of horizontal or
  vertical stripes.
• Kittens responded to visual stimuli in the
  familiar orientation, but not in the unfamiliar
  orientation (e.g. horizontal stripes were ignored
  by cats reared in the presence of vertical
  stripes).
• Visual cortex neurons - activity only present
  with stripes in the familiar orientation.

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A real-world human example?

• When are infants aware of the dangers of falling?
• Does the visual system recognize these dangers
  from the outset...
• ....or do infants learn through experience -
  the hard way?

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2D gt 3D

• Depth perception
• Visual cliff expts. (Gibson Walk, 1960)
• Infants 6-14 months - central platform
• 27/27 gt shallow side
• 3/27 gt deep side (virtual cliff)

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Impact of visual impoverishment(Levtzion-Korach
et al. 2000)

• Normal vision
• Reaching - 3 months
• Crawling - 7 months
• Walking - 12 months

• Blind
• 12 months
• 13 months
• 19 months
• Learning opportunities missed. Delays between 6
  - 9 months

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Theory of perceptual development

• Gibsons ecological theory
• Important to ask 4 questions
• What do infants perceive?
• How is information processed?
• What actions/interactions involved?
• What are the consequences of perception?
• (Gibson Pick, 2000)

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Gibsons ecological theory

• Children perceive affordances - opportunities for
  action/interaction.
• Perception picking up invariant cues from
  environment.
• Third dimension ?constructed present at outset.
• Development discovery new affordances.
• Linked to motor development.

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Gibsons ecological theory what develops?

• Differentiation the increasing efficiency of the
  perceptual system and experience allows children
  to extract information from the environment more
  accurately (i.e., greater detail) and more
  efficiently (e.g., discriminating between
  relevant and irrelevant features)

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Gibsons ecological theory what develops?

• Adult Example
• New piece of alien music (Peking opera
  Classical Indian jazz)
• Difficult to recognize - but repeated listening
  reveals the structure that was there all along..
• Senses attend to relational info - not static info

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Gibsons ecological theory unbelievers?

• One of the main objections to Gibsons theory is
  that in it, cognition perception.
• If perception is direct, why do infants show
  interpretation of the perceived environment?
• If perception cognition.... what is not
  perception?

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Gibsons ecological theory unbelievers?

• As we shall see next time, there is evidence that
  infants believe that their actions have a causal,
  rather than a passive, influence on the world,
  that they impose meaning on what they perceive.
• .enter Jean Piaget.

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Reading

• Berk (1997) - Chap. 4.
• Bremner - p.10 - 21 Chap 3.
• Eysenck - p.487 - 496
• Miller - Chap 6 (for Gibsons theory)
• Smith Cowie - p.251 - 275
• Donaldson, M. (1978/1986) Childrens minds.
  Glasgow Harper Collins
• ( highly recommended)