1. Chapter Three
Tools for Exploring the World: Physical, Perceptual, and Motor Development

2. 3.1 The Newborn: Learning Objectives
How do reflexes help newborns interact with the world?
How do we determine whether a baby is healthy and adjusting to life outside the uterus?
What behavioral states are common among newborns?
What are the different features of temperament? Do they change as children grow?

3. The Newborn’s Reflexes
Reflexes: the newborn is born with unlearned responses triggered by specific stimuli
Certain reflexes have survival value
rooting, sucking, eye blinks
Other reflexes are developmental precursors to later voluntary motor behaviors
stepping a precursor to walking
Reflexes reflect the health of the child’s nervous system

4. Assessing the Newborn The five Apgar scores
1. Heart rate 2. Respiration
3. Muscle tone 4. Reflexes
5. Skin tone
Each scored from 0 to 2; then summed
Good physical condition: total of 7+
Needs special attention: total of 4-6
Life-threatening: total of 3 or less

5. Assessing the Newborn (cont’d)
Neonatal Behavioral Assessment Scale (NBAS)
Includes 28 behavioral and 18 reflex items
Assesses four systems
Autonomic: body regulation (e.g., breathing)
Motor: activity level and control of body
State: maintaining states (e.g., alertness)
Social: interacting with people

6. The Newborn’s States
Alert inactivity: calm, eyes open and attentive; deliberately inspecting environment
Waking activity: open but unfocused eyes; uncoordinated motions
Crying: cries vigorously; motion is agitated and uncoordinated
Sleeping: eyes closed; degree of activity and quality of breathing alternate

7. Crying Basic cry Starts softly and builds in volume and intensity
Often seen when the child is hungry
Mad cry
More intense and louder
Pain cry
Starts with a loud wail, followed by a long pause, then gasping

8. Sleeping Newborns sleep an average of 16-18 hours/day Sleep cycles
Newborns: 4-hour cycle; 3 hours sleep and 1 hour awake
By 3 to 4 months: 5-to-6-hour cycle
By 6 months: sleep 10 to 12 hours at night
REM sleep
50% of newborn sleep
25% by 12 months

9. Co-sleeping
The practice of sleeping in the same room or bed with the child
Much more common in cultures valuing interdependence than independence
Research shows no evidence of increased dependence
Co-sleeping has the advantage of avoiding elaborate sleep-time rituals

10. Sudden Infant Death Syndrome (SIDS)
SIDS: sudden, inexplicable death of a healthy baby
Risk factors
Premature birth and low birth weight
Parental smoking
Child overheating and sleeping on stomach
African-American infants (often sleep on stomach)
Reducing risk? Sleeping on back or sides

11. VIDEO: Preventing SIDS

12. Dimensions of Temperament
Temperament: consistent styles or patterns of infant behavior
Number of temperament dimensions still debated (ranging from 2 to 9)
Rothbart’s (2007) three dimensions indicate how much a child
is generally happy, active, vocal, and seeks stimulation (surgency/extroversion)
is angry, fearful, frustrated, shy, and not easily soothed (negative affect)
focuses attention, is not easily distracted, and can inhibit impulses (effortful control)

13. Rothbart’s Dimensions of Temperament
Three dimensions are not independent
High effortful control predicts high surgency/extroversion, but low negative affect
Scores during infancy predict personality in adolescents and adults

14. Hereditary and Environmental Contributions to Temperament
Heredity and twin studies
Identical twins are more similar in temperament than are fraternal twins
Heredity influences negative affect more than other temperament dimensions
Heredity contributes more to temperament in childhood than during infancy

15. Hereditary and Environmental Contributions to Temperament (cont’d)
Asian babies are less emotional, whereas Russian babies show more fear and negative affect compared to Euro-American babies
Parental characteristics influence temperament
Parental responsiveness reduces infant emotionality
Depressed mothers have more fearful infants

16. Hereditary and Environmental Contributions to Temperament (cont’d)
Heredity and environment interact
Temperament influences environment’s effect on children
Fearful children cheated more if disciplined with power assertion, but less if parents were nurturing and supportive
Temperament influences how others treat the child and his or her experiences

17. Stability of Temperament
Studies suggest that temperament tends to be somewhat stable from infancy through adulthood
Temperament predisposes, but does not always guarantee, later personality characteristics
Parents can nurture children to behave in ways somewhat different from their temperament

18. 3.2 Physical Development: Learning Objectives
How do height and weight change from birth to two years of age?
What nutrients do young children need? How are they best provided?
What are the consequences of malnutrition? How can it be treated?
What are nerve cells, and how are they organized in the brain?
How does the brain develop? When does it begin to function?

19. Growth of the Body
Growth is more rapid in infancy than during any other period after birth
Infants double their weight by three months
Infants triple their weight by one year
Average is not the same as normal
Children of the same age can vary greatly in their heights and weights
Height depends largely on heredity

20. FIG 3.2 Boys and girls grew taller and heavier from birth to 3 years of age but the range of normal heights and weights is quite wide.

21. Nutrition and Growth
Rapid growth requires young babies to consume large amounts of calories relative to body weight
Breast-feeding is the best way to ensure proper nourishment
Bottle-feeding has advantages and disadvantages
All family members can enjoy intimacy with bottle
Formulas can promote proneness to allergies and reduced immunity

22. Nutrition and Feeding New foods should be introduced one at a time
Growth slows at two years and children become finicky eaters
Finicky eating may have survival value
Toddlers do not know which foods are safe and stick with familiar foods
Virtually all finicky eaters receive adequate nutrition
New foods still introduced one at a time

23. Malnutrition
World-wide about 1 in 4 children under age five are malnourished (UNICEF, 2006)
Malnourished children develop more slowly
Malnutrition is most damaging during infancy due to rapid growth rate
Giving malnourished children adequate diets is challenging because they are listless, quiet, and inactive
These characteristics call less urgent attention to the children’s needs

24. The Emerging Nervous System
The brain and the rest of the nervous system consist of cells known as neurons
Neurons consist of a soma, dendrites, the axon, and terminal buttons
Terminal buttons release chemicals called neurotransmitters

25. FIG 3.4 A nerve cell includes dendrites that receive information, a cell body has life-sustaining machinery, and, for sending information, an axon that ends in terminal buttons.

26. The Brain The brain has 50 to 100 billion neurons
Cerebral cortex: the wrinkled surface of the brain
Hemispheres: the two halves of the brain
Corpus callosum: the thick band of fibers connecting the two hemispheres

27. The Making of the Working Brain
The brain weighs about three-quarters of a pound at birth – about 25% of an adult brain
At around three years of age, the child’s brain is about 80% of an adult’s brain weight

28. Emerging Brain Structures
At 3 weeks after conception, the neural plate, a flat structure of cells, forms
By 28 weeks after conception, the brain has all the neurons it will ever have
In the 4th month of prenatal development, axons begin to form the fatty sheath, myelin
Helps speed neural transmission
Improves coordination and reaction times
Number of synapses peaks at 12 months
Synaptic pruning: certain unnecessary synapses soon begin to disappear

29. Growth of a Specialized Brain: Brain-Mapping Methods
Methods to study origins and time course of brain specialization
Studying children with brain damage
Measuring the brain’s electrical activity through electrodes place on scalp (EEG or electroencephalogram)
Using magnetic fields to track brain blood flow (fMRI, functional magnetic resonance imaging)

30. Five General Principles of Brain Specialization
Specialization is early in development
Ex.: newborns’ left hemisphere generates higher electricity in response to speech
Specialization takes two specific forms
Specialized areas become more focused and less diffuse
Stimuli triggering brain activity become more specific than general

31. Five General Principles of Brain Specialization (cont’d)
3. Different brain systems specialize at different rates
Ex.: systems for sensory and perceptual processes specialize before those for higher-order processes
4. Environmental stimulation is necessary for successful specialization
experience-expectant growth
experience-dependent growth

32. Five General Principles of Brain Specialization (cont’d)
5. Plasticity is a benefit of the immature brain’s lack of specialization
Atypical experiences may disrupt normal course of development (e.g., brain damage disrupting speech)
Plasticity: brain is very flexible, allowing recovery of function, especially in young children

33. Experience-expectant growth
Brain Specialization Principle: Experience-Expectant vs. Dependent-Growth
Experience-expectant growth
All human brains require exposure to experiences common to all individuals (e.g., exposure to faces) to fine-tune their circuits and to have different regions specialize
Experience-dependent growth
Brain circuits and regions also are fine-tuned according to each person’s unique experiences (e.g., learning to play the violin vs. learning to play soccer)

34. VIDEO: Visual-Spatial Processing

35. 3.3 Early Motor Skills: Learning Objectives
What are the component skills involved in learning to walk? At what age do infants master them?
How do infants learn to coordinate the use of their hands?

36. FIG 3.5 Locomotor skills improve rapidly in the 15 months after birth and progress can be measured by many developmental milestones.

37. Locomotion By 7 months, infants can sit alone
Toddling: at around 14 months, toddlers may stand alone briefly and walk without assistance
Dynamic systems theory
Instead of simple maturation, motor development involves many distinct skills that are organized and reorganized over time to meet specific task demands

38. Posture and Balance
Infants are “top-heavy” and easily lose their balance
Within a few months, infants use inner ear and visual cues to adjust posture
Infants must relearn balance each time they achieve new postures

39. Stepping
Many infants move their legs alternately in a stepping-like motion as early as 6-7 months
Infants use environmental cues to judge whether a surface is suited to walking (e.g., flat vs. bumpy)

40. Coordinating Skills
Walking skills must be learned separately and then integrated with others
Differentiation: mastery of component skills
Integration: combining components into the sequence needed to accomplish the task
Unsupported, independent walking occurs at about 12 to 15 months, once children have mastered and coordinated its component skills

41. Cultural Impact on Motor Development
Some cultural practices encourage certain skills early and others discourage them
Ex.: parents in Africa carry children piggyback style, which promotes walking at earlier ages than in the U.S.
Ex.: in Paraguay, mothers constantly carry toddlers, delaying motor skills
Despite cultural differences in average age of skill development, children acquire skills within a normal range
Uh, I don’t see how these two examples differ from each other…elaborate?

42. Fine Motor Skills
Fine motor skills are associated with grasping, holding, and manipulating objects
At 4 months, infants clumsily reach for objects
By 5 months, they coordinate movement of the two hands
By 2-3 years, children can use zippers but not buttons
Tying shoes is a skill that develops around age 6 years

43. Handedness About 90% of children prefer to use their right hand
Most children grasp with their right hand by age 12 months, with a clear preference seen by preschool age
Preference is affected by heredity, but environmental factors also influences it
Left-handedness has increased since U.S. teachers stopped urging right-handedness

44. 3.4 Perception: Learning Objectives
Are infants able to smell, to taste, and to experience pain?
Can infants hear? How do they use sound to locate objects?
How well can infants see? Can they see color and depth?
How do infants coordinate information between different sensory modalities, such as between vision and hearing?

45. Coming to Know the World: Smell and Taste Perception
Perception: brain processes receiving, selecting, modifying, and organizing sensory inputs
Newborns have keen senses of smell and taste
Odors: they distinguish pleasant from unpleasant, or familiar from unfamiliar (e.g., mother’s breast or perfume)
Taste: they differentiate among salty, sour, bitter, sweet, and changes in mother’s breast milk
Facial reactions (e.g., lip licking) show they have a “sweet tooth”

46. Coming to Know the World: Touch and Pain
Babies react to touch with reflexes and other movements
In reaction to painful stimuli, babies manifest the pain cry – a sudden, high-pitched wail – and they are not easily soothed

47. Coming to Know the World: Hearing
Startle reactions suggest that infants are sensitive to sound
Infants hear less well than adults
They best hear pitches in the range of human speech (neither high nor low pitches) and differentiate consonants from vowels
They prefer pleasant more than unpleasant melodies and can remember songs
By 4 months, they recognize their own names

48. Coming to Know the World: Seeing
Newborns respond to light and track moving objects with their eyes
Visual acuity (clarity of vision) is the smallest pattern that can be distinguished dependably
Infants at 1 month see at 20 feet what adults see at feet
By 1 year, infants’ visual acuity is the same as adults

49. Coming to Know the World: Color
Cones: sets of neurons located along the retina at the back of the eye, each specialized to one of the three light wavelengths
Newborns perceive few colors
3- to 4-month-old infants can perceive colors similarly to adults

50. Coming to Know the World: Depth Perception
Visual cliff research
6-week-olds react with interest to differences in depth (heart rate deceleration)
By 7 months, they show more fear than interest to the cliff’s deep end (heart rate acceleration and refusal to cross the deep side)
Fear of depth seems to develop around the time babies can crawl

51. Coming to Know the World: Depth Perception (cont’d)
Seven cues adults use to infer depth
Cues Closer compared to distant objects...
Kinetic cues … appear larger while moving
Visual expansion … fill more of the retina
Motion parallax … move faster
Retinal disparity … yield greater disparity
Sound … sound louder
Pictorial cues
Linear perspective … have wider parallel lines
Texture gradient … are coarser and distinctly textured

52. Coming to Know the World: Depth Perception (cont’d)
Few-week old babies use kinetic, visual expansion, and motion parallax weeks after birth to see depth
Infants use sound to accurately gauge depth
4- to 6-month-old babies use retinal disparity
7-month-old babies use linear perspective and texture gradient to see depth

53. Coming to Know the World: Perceiving Objects
Perceiving objects involves interpreting patterns of lines, textures, and colors
Object perception is limited in newborns, but develops rapidly in the first few months
By 4 months, infants use several cues to discern that a stimulus is an object
elements that move together
similar colors and textures
aligned edges

54. Perceiving Faces
Newborns prefer to look at moving faces, suggesting an innate attraction to them
By 4 weeks, infants track all moving stimuli, including faces and nonfaces
Before 6 months, infants have a prototype of a face that includes both human and nonhuman faces
Between 6 to 12 months, the prototype is fine-tuned to reflect familiar faces, which they prefer viewing
By 7 to 8 months, infants process faces similarly to adults, as a unique arrangement of features

55. Integrating Sensory Information
Infants visually recognize objects they only touched previously
Infants soon begin to perceive the link between visual images and sounds
Intersensory redundancy: simultaneously available multimodal sensory information (e.g., sight, sound, touch)
Infants perceive best when sensory information is redundant
Why? Brain regions specialized for a specific sense are not yet developed

56. 3.5 Becoming Self-Aware: Learning Objectives
When do children begin to realize that they exist?
What are toddlers’ and preschoolers’ self-concepts like?
When do preschool children begin to acquire a theory of mind?

57. Origins of Self-Concept
Self-awareness
Mirror test: red rouge surreptitiously rubbed on child’s nose; child placed in front of mirror and behavior is observed
9-month-old infants smile at the image in the mirror but do not seem to recognize it as themselves
By months, infants see the image in the mirror and touch their own nose, suggesting they know the image is theirs

58. Origins of Self-Concept (cont’d)
Toddlers look more at photographs of themselves than other children
Toddlers refer to themselves by name and use personal pronouns “I” or “me”
They use “I” in the present and in the past, showing awareness of the self’s continuity over time
Toddlers understand ownership, indicated by use of “mine” in reference to possessions
Preschoolers describe the self in terms of possessions, physical characteristics, preferences, and competencies

59. Theory of Mind (TOM)
Theory of mind: naïve understanding of the relationship between mind and behavior
Develops in three phases (Wellman, 1993, 2002)
Phase 1: by 2 years, aware of desires; speak of wants and likes
Understand that people have desires and that desires cause behavior (e.g., “Ew peas; I not eat.”)
Phase 2: by 3 years, distinguish the mental from physical world
Use mental verbs (“think”, “believe”, “forget”), but still emphasize desires as main causes of behavior

60. Theory of Mind (TOM) (cont’d)
Phase 3: by 4 years, know that behavior can be based on beliefs about events, even if belief is false
False belief tasks
Child hears story about Sally, who puts ball in the basket and leaves
Child told the ball is moved from the basket to the box, which Sally does not know
Child is asked, “When Sally comes back, where will Sally look for the ball ”
3 &1/2-year-olds: Sally will look in the box (wrong)
4-year-olds: Sally will look in the basket (correct)

61. Theory of Mind (TOM) (cont’d)
How does TOM develop?
Could reflect expanding mental state language and grammatical skills
Might be due to interactions with others, who provide insights into people with different mental states, perspectives, feelings, intentions, moods
TOM and autism
Autism spectrum disorder (ASD)
Echoic speech and later language acquisition
Obsessive and compulsive interest in objects
Disinterest in other people

62. Theory of Mind (TOM) (cont’d)
Autism spectrum disorder (ASD) (cont’d)
Awkward social interactions with other people
Do not follow rules governing social interactions
Symptoms emerge around 18 to 24 months
Diagnosed in 1 out of U.S. children
80% of diagnoses are in boys
Is heritable
Atypical brain functioning; perhaps abnormal neurotransmitter levels
Cannot be cured, but medications and a supportive environment help a lot

63. Theory of Mind (TOM) (cont’d)
ASD and TOM
Very slowly grasp false belief
Some argue they may not have a TOM
mindblindness is a defining feature of ASD
Some attribute mindblindedness to other deficits
cannot inhibit irrelevant actions
have problems shifting smoothly between actions
Some attribute to a “focused” processing style
too much emphasis on perceptual details instead of the bigger coherent picture