Unit 2

• Body changes:

  • Birth- 1 year: lots of physical change
  • New borns lose weight in the first 3 days, then gain one ounce per day for month, water weight
  • Average birth wt is 7 pounds, doubles by 4th month, triples by 1 year
  • Average birth length is 20 inches; newborn grows 10 inches by age 1
  • Form year 1 to 2: physical growth slows
  • Substantial variation: we can compare babies to norms (avg) and look at percentiles (rank compared to others the same age)
• Weight by gender:

  • Usually boys are heavier
  • Unhealthy weight can lead to increase likelihood poor health later in life (asthma, heart disease, diabetes)
  • overweight: rapid gain
  • underweight: prematurity
• Height by gender:

  • boys are usually taller
• Threats to physical health: malnutrition

  • Malnutrition: person doesn't consume sufficient food of any kind that can result in severe illnesses, weight loss, and even death
  • Stunting: failure to grow to a normal height for their age
  • Wasting: tendency for children to be severely underweight for their age
• Effects of Chronic malnutrition:

  • learning suffers due to effects on brain
  • diseases are more serious/lethal
  • some disease result directly from malnutrition:
  • Marasmus: under age 1, body tissue wastes away
  • Kwashiorkor: after age 1, growth slows, hair thins, skin splotchy, abdomen, face, and legs swell with fluid
• Infant nutrition:

  • Feeding babies:
  • Early food and feeding patterns vary
  • all infants must be fed frequently
  • Breastfeeding: "breast is the best"
  • Colostrum: before milk, 2-3 days after birth
  • More easily digestible, nutrient-rich, antibodies, increase health
• More on nutrition:

  • Milk is ideal until about 6 month, 2 years is the max
  • More common in higher income families
  • More common in Latin vs white and black
  • difficulties of breastfeeding and social/medical support
• Other source of nutrition:

  • Commercial formula: mix of cow's milk, soy or corn, but very expensive
  • Bottle propping: should be avoided because it is risky for overeating or suffocation
  • Solid foods: okay after 6 months, influenced by marketing? early food experience helps determine life long taste
• Patterns of infant sleep:

  • Newborns average 15 to 17 hours of sleep but wake up frequently bc they haven't developed a circadian rhythm and need to be fed often
  • Half of newborn sleep is REM "active" sleep, so lots of momvemnt
  • REM sleep declines and by month 4 time slow wave sleep "deep sleep" has increased (dev circadian rhythm)
  • At month 5, most babies sleep at night for at least 5 hours
  • Babies under 12 months who "sleep" through the night may actually wake up 3-4 times a night, but fall back asleep
  • After year 1, 1-2 daytime naps remain common with babies still sleeping 12 to 16 hours
• Patterns of infant sleep:

  • individual differences due to maturation of genes and environments
  • caregiver response to infant behavior during sleep hours also impacts sleep patterns
  • Insufficient sleep may be a problem for both parent and infant
• Co-sleeping:

  • Minorities are more concerned with seperation while whites are more concerned with privacy and gender
  • Pros: quick response time, increased response attachment
  • Cons: higher SIDS, later sleep pattern problem
• Infant brain development:

  • most neurons are created before birth
  • brain growth starts from down to up ... cerebellum first and frontal Cortex last
  • Head sparing: body weight is lost before brain weight, happens when body is physically challenged
• Connections and brain:

  • Structure: axons, dendrites
  • Process: synaptogenesis
  • Neural connections: synaptic creations and pruning and myelination
• Axon: sends signal to other neurons
• Dendrites: receive signals from other neurons
• Synaptogenesis: the formation of new synapses in the brain; before birth and continues through lifespan
• Synaptic pruning: brain cuts back on synapses; allows for more complex thinking
• Myelination: The process of insulating the axon with myelin sheaths
• Transient exuberance: increase number of dendrites during first two years.. only temporary
• Experience expectant: relies on nearly universal environmental inputs (sensitive periods); basic experiences that children would suffer without
• Experience dependent: relies on quantity or quality of environment (NOT tied to specific time or sensitive period), not harmful if they don't get these experiences
• Infant brain needs..

  • necessary stimulation
  • stress
  • severe social deprivation
• Shaken Baby Syndrome:

  • young babies have weak neck muscles, so this results in head injury or whiplash; ruptured blood vessels in brain, prevents brain from getting enough oxygen
  • Symptoms: fussiness, irritability, difficulty staying awake, breathing, vomiting, pale/bluish skin, seizures,
  • Consequences: cerebral palsy, developmental delays, total or partial blindness
• Sensation: response of a sensory system when it detects stimuli

  • perception follows sensation... the interpretation of sensation
• Hearing:

  • develops during last trimester, MOST advanced, speech perception by 4 months (not whispers)
  • 6 months: high pitch
  • 2 years: difficulty ignoring background noises
  • 7 to 8 months: perceptual narrowing
  • speech is tight with language
• Sight:

  • Least mature sense at birth
  • Focus between 4 and 30 inches
  • Drawn to faces, people, and animals
  • Binocular and color vision occurs at 3 months
  • Perceptual tuning: more specialization over 1st year
  • vision connected with motor skills
• Misc sense:

  • Smell:
  • functions at birth, recognize smell of mother, dislike and preference of certain smells
  • Taste:
  • functional at birth(amniotic fluid), taste preference
• Touch: it's acute in infants, prefer specific touches
• Pain:

  • pain and temperature are connected to touch
  • Newborn heel prick to test for genetic diseases
  • Belief that sense of pain matures as axons in the brain connect more
  • soothing pain: touch, distractions, sucking
• Motor skills: gross motor skills

  • first movements are reflexes
  • physical abilities involving large body movements
  • follows cephalocaudal and proximodistal
  • 3 elements of motor skills
  • muscle strength: core, legs
  • brain maturation: coordination of action
  • practice: tummy time, motivation, sticky mittens
• Motor skills: fine motor skills

  • small body movements with emphasis on hands and fingers
  • shaped by culture and opportunity
  • Palmar grasp: reflex to grab if something put in hand, present in fetal and newborn period, but disappears by 6 months
  • Pincer grasp: forefinger and thumb, devs btwn 9 and 12 months
• Independent movement: changes how infant experiences world and how others relate to infant, helps learn about physical world possibilities, visual cliff
• Cultural variation:

  • Age of acquisition varies, black walk earlier
  • influenced by genes, cultural patterns, nutrition, caregiver
  • difference is not deficit: slow development is relative to local norms
• SIDS, most infants found sleeping on their stomachs
• Immunizations:

  • primes the body's immune system to resits a particular disease
  • unsafe for: embryo exposed to rubella, newborns (less than 3 months) and ppl with compromised immune systems
  • Herd immunity: if less than 90% are immunized, then vaccine's resistance lowers
  • challenges with COVID
• Hearing in Newborns:

  • hearing is the most advanced, can hear all noises, but ignore most
  • babies are universalist: hear differences in any language
  • perceptual narrowing by 7 to 8 months
  • by month 12 , ability to distinguish sounds in never-heard languages deteriorates
• Gaze following: young infants responsively follow gaze of adult to learn what's important

  • adults use natural pedagogy (natural tendency to teach infants)
• Facial recognition:

  • newborns are drawn to faces.. experience expectant
  • Smile more readily at familiar faces, diff from women vs men and ethnic group ... experience dependent
• Infants innate understanding:

  • Early logic: young infants demonstrate some understanding of how things should be; study: duration is longer for unexpected events
  • Core knowledge
  • Nativist theory: babies have innate understanding of how the world works
  • core expectation prime learning and alert infant
  • core knowledge and plasticity make rapid learning possible
• Memory in infants:

  • Memory improves with maturation; needs to be in explicit to stay
  • Implicit: movement, emotions, impulses, beings at 3 and stabilizes by 9 months, unconscious, learning by immediate response to behavior
  • Explicit: takes longer to emerge, depends on language, improves through childhood, cortex dev.