This document summarizes key aspects of physical and cognitive development in infancy. It discusses how the brain develops rapidly after birth, with neural connections proliferating. It outlines developmental milestones in infants' motor skills, language, senses, and cognition. Piaget's theory of cognitive development through sensorimotor stages is described. The document also notes declining rates of Sudden Infant Death Syndrome as more parents follow safe sleep practices.

1. CHAPTER 3
PHYSICAL AND COGNITIVE
DEVELOPMENT IN INFANCY

2. THE BRAIN
• Contains tens of billions of nerve cells at birth
• Shaken baby syndrome - Brain swelling and
hemorrhaging
• Brain’s development
• Lateralization
3-2
Four Lobes

3. DENDRITIC SPREADING
3-3

4. SYNAPTIC DENSITY IN THE HUMAN BRAIN
FROM INFANCY TO ADULTHOOD
3-4

5. THE COMPETENT NEWBORN
Reflexes
[Surgery]

6. SENSORY CAPABILITIES OF THE
NEWBORN

7. HABITUATION/DEHABITUATION

8. HABITUATION/DEHABITUATION
What does habituation imply about memory processes of infants?

9. CEPHALOCAUDAL AND
PROXIMODISTAL PATTERNS
• Cephalocaudal
• Proximodistal
• Hierarchical integration

10. THE FIRST YEAR
• Average North American (full term) newborn ~ 20 inches
long; 7 pounds
• Lose ~5 to 7% of body weight adjusting to feeding. Back
to birth wt in 2 wks.
• Double birth weight by 5 months; nearly triple by 12
months

11. THE FIRST TWO YEARS
1 year: ~30 inches tall.
2 years: ~35 inches tall—
nearly half of their eventual
adult height

12. INTEGRATING THE BODILY SYSTEMS:
THE LIFE CYCLES OF INFANCY
Behavior becomes integrated through the
development of various body rhythms

13. SLEEP
• Considerable individual variation
• newborns can sleep 16 to 18 hours a day (average
~16)
• preferred patterns of sleep vary
• Infants spend a greater amount of time in REM
(rapid eye movement) sleep
• by 3 months of age, the percentage of time in REM
sleep decreases [next]

15. SIDS
• Children in U.S. = 1910 (2011)
• The leading cause of death in children under 1
year old (except for congenital abnormalities and
short gestation)
• Risk of SIDS is highest at 4 to 6 weeks of age
• Occurs in children of every race and
socioeconomic group
(Congenital abnormalities = 5013; Short gestation = 4106)

16. DECLINING RATES OF SIDS
SIDS Rate and Back Sleeping
(1988 – 2006)
1.4 1.39
1.3 1.3
1.2 1.17
1.03
0.87
0.77
55.7
0.74 0.72
64.4 66.6
0.67
0.62
72.2
75.7
71.6 71.1 72.8
70.1
0.56 0.57 0.53 0.56 0.54 0.55
17
13
26.9
38.6 35.3 53.1
1.5
1.0
0.5
0.0
19 88
19 89
19 90
19 91
19 92
19 93
19 94
19 95
19 96
19 97
19 98
19 99
20 00
20 01
20 02
20 03
20 04
20 05
20 06
AAP Recommendation Back to Sleep Campaign
Year
SIDS Rate
(Deaths Per 1,000 Live Births)
100
50
0
Percent Back Sleeping
SIDS Rate Source: CDC, National Center for Health Statistics,
Sleep Position Data: NICHD, National Infant Sleep Position Study.
U.S. rates have dropped dramatically as parents put babies “back to sleep.”

17. GROSS MOTOR SKILLS — LARGE
MUSCLE ACTIVITIES
• Move by themselves - 6
months
• Sit unsupported - 6
months.
• Crawling - 8-10 months
• Standing with support - 8
months
• Infants can walk holding
onto furniture by 9 months
and walk alone by ~1 year.

18. Physical Milestones
First Year
Eating:
• Can begin using a “sippy cup”
• Can be spoon fed
• Can be introduced to SMALL-SIZED solid foods
Small Motor Coordination:
• Can pick up toys in both hands (and bang them together!)
•Will practice dropping objects
• May throw objects (especially…everything)
•Will begin to pick up “Cheerios” or other small object with thumb
and index finger

19. FINE MOTOR SKILLS
• By 3 months infants
can coordinate
movements of
limbs.
• Infants can grasp an
object by 11
months.
• By age 2, infants
can drink from a cup
without spilling.

20. BENEFITS OF BREAST FEEDING
• Appropriate weight gain; lowered risk of childhood obesity
• Fewer allergies
• Reduction of diarrhea, respiratory infections, bacterial and
urinary tract infections
• Denser bones in childhood and adulthood
• Reduced childhood cancer and reduced incidence of breast
cancer in mothers
• Lower incidence of SIDS

21. Breast Feeding

22. Breast Feeding

23. Breast Feeding

24. INTRODUCING SOLID FOODS
• Most babies begin to eat solid foods b/t 4-6
months
• Foods are introduced gradually
• Weaning

25. DEVELOPMENT OF THE SENSES
Infants hear from the time they are born—
and even before

26. VISION
Infants show clear visual preferences that are present
at birth:
• Prefer to look at patterns and complex stimuli,
• Prefer to look at faces,
• Minutes after birth they show a preference for
certain colors, shapes, configurations.
Robert Fantz found
that 2- and 3-month-old
infants preferred
to look at more
complex stimuli.

27. VISION, CONT.
• Newborn infants cannot see beyond a distance of 20 feet
• By ~6 months, the average infant's vision is 20/20
• Gibson's "visual cliff" experiments indicates depth
perception

28. VISUAL PERCEPTION

29. HEARING, TOUCH, AND PAIN
• Prenatally at 7 months, infants can hear
sounds such as mother’s voice and music
• Immediately after birth, infants cannot hear
soft sounds or pitch as well as adults do
• Infants also display amazing resiliency
• Within several minutes after the circumcision
surgery (which is performed without
anesthesia), they can nurse and interact in a
normal manner with their mothers

30. SMELL AND TASTE
• Newborns can differentiate odors
• Sensitivity to taste might be present even before birth
• At only 2 hours of age, babies made different facial
expressions when they tasted sweet, sour, and bitter
solutions

31. COGNITIVE DEVELOPMENT IN
INFANCY
© 2006 Pearson Education/Prentice-Hall Publishing

32. Infant cognition develops through changes in the way
children approach problems (infants learn by doing).

33. ASSIMILATION AND ACCOMMODATION
• Processes of development
• Schemes:
• Behavioral scheme
• Mental scheme
• Assimilation: Using existing schemes to deal with new
information or experiences
• Accommodation: Adjusting schemes to fit new information
and experiences
Which one?
1. Infant uses sucking schema to suck on larger bottle/nipple after presentation of smaller
one.
2. One-year-old grabs every “round, rolly object” and tries to grab and throw; sees a beach
ball.

34. PIAGET
• Equilibration
• Individuals go through four
stages of development
• Cognition is qualitatively different
• Sensorimotor stage: Lasts from birth to about age 2.
• Infants construct an understanding of the world by coordinating
sensory experiences (such as seeing and hearing) with physical
actions
• Object permanence: Understanding that objects and
events continue to exist:
• When they cannot directly be seen, heard, or touched
3-34

35. SENSORIMOTOR STAGE
• Six substages
 Primary: reflexes determine interaction
• Accidentally sucks fist, feels good, so suck some more (provides
info about the world = cognitive development).
• Secondary: Begins to act on world (e.g., Rattles a rattle)
• Repeats actions; Goal-directed behavior; Develops object
permanence
• Tertiary circular reactions: deliberate variation of
actions
 Miniature “experiments” Hit drum, then table, then floor, then
head with a stick
• Beginning of thought ~18-24 months of age
• Mental representation

36. EVALUATING AND MODIFYING
PIAGET’S SENSORIMOTOR
STAGE
• Motor emphasized at the expense of sensory
-–largely ignores sensory and perceptual
abilities of infants
• Piaget's claim that certain processes are
crucial in stage transitions is not always
supported by the data
• Some researchers conclude that infants’
perceptual abilities are highly developed
very early in development
Criticism of Piaget

37. LANGUAGE DEVELOPMENT
• All human languages have
some common
characteristics
• Receptive/expressive
You talkin’ to me?!

38. KEY MILESTONES IN LANGUAGE
DEVELOPMENT
• Babies' sounds and gestures go through this
sequence during the first year
• Crying:
• Cooing:
• Babbling: [text is wrong]
• First Words ~ 10 to 14 months
• Average is 15 words by 15 months; First words are typically
holophrases (Holophrastic stage ~12-18 months)

39. LANGUAGE SOUNDS
• ~ 2-years-old, children can form noun-verb
sentences
• Overextension
• Underextension

40. A one-year-old
signing “sleep”

41. LEARNING THEORY/NATIVIST
APPROACHES
• Learning theory
• Chomsky > genetic;
innate mechanism
• All languages > similar
underlying structure
• LAD
• Interactionist view

42. INFANT-DIRECTED SPEECH (IDS)
[MOTHERESE]
 Use of this type of speech is related
to the early appearance of words

43. FIGURE 3.9 - MILESTONES IN GROSS
MOTOR DEVELOPMENT
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