Infancy & Childhood Modules 45 & 46: Physical Development

Infant Abilities Infants are born with immature visual system –can detect movement and large objects Other senses function well on day 1 –will orient to sounds –turn away from unpleasant odors –prefer sweet to sour tastes Senses are keenly attuned to people, helping the infant quickly learn to differentiate between the mother and other humans. Born with a number of reflex behaviors

Newborn and APGAR Readings Watch “Testing Competency In a Newborn”Testing Competency In a Newborn –Video #13 from Worth’s Digital Media Archive DVD (2 min) A = Activity or Muscle Tone P = Pulse (100 beats per minute) G = Grimace (sneeze & cough to suction of nose & mouth) A = Appearance (normal skin color) R = Respiration (cry & breath regularly) Click Here to Play in Separate Window

Infant Reflexes Reflex is an automatic, unlearned response Rooting—turning the head and opening the mouth in the direction of a touch on the cheek. Child is looking for nourishment. Sucking—sucking rhythmically in response to oral stimulation Grasping—curling the fingers around an object Babinski—fanning and curling toes when foot is stroked Moro—throwing the arms out, arching the back and bringing the arms together as if to hold onto something (in response to loud noise or sudden change in position of the head) Swimming – if submerged, infants hold breath and pump arms & legs Stepping – move feet up and down when held up over a flat surface

Reflexes in the Newborn Watch “Reflexes in the Newborn” (2 min)Reflexes in the Newborn –Video #14 from Worth’s Digital Media Archive DVD Click Here if you to watch this in a separate window

Physical Development in Infancy and Childhood

Infant, Toddler, Child Infant: First year Toddler: From about 1 year to 3 years of age Child: Span between toddler and teen

Infancy and Childhood: The Developing Brain

Neural Development At birth, the newborn’s brain is 25% of its adult weight; its birth weight, by contrast, is 5% of its eventual adult weight By the end of infancy a baby’s brain will be 75% of its adult weight but their body and height will be about 20% Newborns enter the world with an estimated 23 billion neurons. After birth, the brain continues to develop rapidly. The number of dendrites increases dramatically during the first two years of life. From 3 to 6, front lobes show rapid growth (rational planning) Association Areas (thinking, memory & language) last areas to develop The axons of many neurons acquire myelin, the white, fatty covering that increases a neuron’s communication speed. Pruning Process - As time goes on, neurons not used are eliminated or rewired (Use it or Lose it)

Neural Development

Pruning Synaptic Connections By age 6, the child’s brain is about 95 percent of its adult size Although overall brain size doesn’t change during childhood and adolescence, dramatic changes in the number of interconnections occur Unused dendrites, synaptic connections, and neurons are discarded (Use it or Lose it)

Infancy and Childhood: Motor Development

Maturation Orderly sequence of biological growth Maturation (Nature) sets the basic course of development: Experience (Nurture) adjusts it.

Motor Development Includes all physical skills and muscular coordination The basic sequence of motor skill development during infancy is universal, but the average ages can be a little deceptive. Each infant has his or her own genetically programmed timetable of physical maturation and developmental readiness to master different motor skills.

Motor Development Play “Baby Body Sense” (11:00)Baby Body Sense –Segment #24 from Scientific American Frontiers DVD

Infant Memory Infantile Amnesia – inability to remember events from before our 3 rd birthday Hippocampus & Frontal Lobes not fully mature until adolescence Brain does show ability to process & store memories before age 3 –Carolyn Rovee-Collier mobile experiment with infants demonstrates this (2 min)Carolyn Rovee-Collier mobile experiment