PSYC 2010U Lecture Notes - Lecture 4: Childhood Amnesia, Dishabituation, Pacifier
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Lecture 4:
Infancy: Physical, Perceptual, & Cognitive Development
Lecture Overview
• Testing Infants
• What babies perceive
▫ Visual
▫ Hearing
• What babies do
▫ Reflexes
▫ Locomotion
• Cognitive Development birth to 2 years
▫ Piaget’s Theor of Cogitie Deelopet
A Debate!
• The world of a newborn has been debated:
▫ …a uzzig, looig ofusio Jaes
• “uggested ifats do’t hae orderl as of pereiig their orld
• Environmental experience shapes how they perceive the world
▫ the preoious ifat
• Quite adult like in their abilities
• More advanced
• Biology plays a critical role
• Why is there a debate?
▫ No a for ifat to ouiate hat the ko ad hat the do’t ko
▫ Infantile amnesia
▫ Ca’t talk or reah for thigs
Testing Infants – 1. Habituation Studies
• Present 1 stimulus until infant becomes bored, then present new stimulus
• If infant can tell the difference between old and new stimuli, s/he will recover attention
(dishabituation)
• Measure attetio through oert ehaior ad/or phsiologial easures
• How long they look at something, sucking a pacifier, biological measures
find more resources at oneclass.com
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Habituation with Pacifier
• Infants heard a specific sound while sucking on a pacifier
o Control group kept hearing the sound and stopped
sucking
o The other group who heard the new sound
increased their frequency of sucking on the
pacifier
Testing Infants – 2. Visual Preference Studies
• Present 2 stimuli, measure attention to both
• If infant pays more attention to one stimulus, s/he:
a) Notices the difference
b) Prefers oe stiulus oer the other
c) What do e ea prefer?
• Tricky to apply this term
• In one situation it could mean that they are familiar with the stimuli
• OR the hae’t heard the stiuli efore
A General Principle
• Central Theme:
▫ The child as a plant!
• biologically prepared to learn about the world, but
experiences critically shape the development of
that knowledge
What can babies perceive?
• Vision:
▫ Visual acuity – ho sharp is aies’ isio?
▫ testing using black and white stripes
• infants prefer looking at stripes and contrast
• if the baby looks at the stripes instead of the box they can see the stripes
• stripes thickness is decreased until they no longer see a difference and
that’s hat their isual auit is liited too
The Development of Acuity
• Birth 20/300 to 20/600 – very near sighted – limited peripheral vision from birth
• 6months: 20/100
• 12months: 20/50
• 3-4yrs: 20/20
• 7-8 months – they start crawling and their visual acuity is beginning to approach adult
like levels
find more resources at oneclass.com
find more resources at oneclass.com
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• Peripheral vision is around that of an adult
• Motor development drives their visual and perceptual development
Visual Scanning
• At 1 month old they focus on particular
part of something and the outside
o Can recognize mother because of
the contour of the face
o If ou ske the o’s hairlie the
will have trouble recognizing their
mom
o Sensation
• Within 4 more weeks (2 months old) they start to observe more of the object
o They start to observe more than just the general shape of a face
o Perception
Where vs. What
Colour Perception
• Colours?
▫ Newborns
▫ Can distinguish between most colors
▫ Alost at a adult’s leel
▫ Trouble distinguishing colours like yellow and white or light gray and dark gray
• Brightness?
▫ Newborn
▫ 2 months
• Can discriminate basic colours
▫ 4 months
• Can group colours into the same categories
Visual Preferences
• Sharp contours
• Love dark colours and light colours (they like contrast0
• High contour density
• More edging is better
• Wavy objects with more contours
• Patterned figures over plain ones
• Like busy patterns
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
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