Physical Development in Infancy

1. Physical Development in Infancy

2. Physical Growth and Development In Infancy Cephalocaudal & Proximodistal Patterns • Cephalocaudal sequence in which greatest growth occurs at top (head), working its way to neck, shoulders, middle truck, so on… • Proximodistal sequence in which growth starts at center of body & moves toward extremities

3. Cepahalocaudal development – head to toe Proximodistal development – inside out Development inside the womb and out

4. Principle of hierarchical integration – simple skills must be met before more complex skills can be achieved i.e., learning how to hold pencil precedes writing Principle of independent systems – different rates of growth within the body i.e., height and weight can be independent of each other Physical development

5. Height and Weight • Infants double their birthweight by four months of age, tripled it by their first birthday, & grow an inch a month during their first year • By 2 years of age, infants weigh approximately 26 to 32 pounds & have reached about one-half of their adult height

9. The Brain • Child is born with 100 billion nerve cells • Neuron - nerve cell that processes information at cellular level. • Dendrites receive information from other neurons, muscle or glands • Axon transmits information • Myelin sheath speeds information transmission • Axon ends are the terminal buttons of the neuron

10. The Brain’s Development • Between 10 and 26 weeks, the neuron connections are generated at 250,000 per minute • Following this cells move to appropriate locations in brain in process called migration • Finally, they are ready for collecting & processing information, known as cell elaboration

11. Early Experience and the Brain • Scientific research on animals & humans who have suffered brain damage, tells us that brain produces trillions of cells in early development which cannot possibly be used • Animals reared in richly-stimulated environments have more neuronal connections than those reared in restricted environments • Implication is children who are given a rich environment very early on, will develop greater neuronal connections for later useThere is some skepticism of this belief

12. Maturation-genetic map – cannot alter this However, this does not mean that environment cannot affect anything Marion Diamond’s research

13. Demonstrated that an enriched environment will increase cell weight and add to the number of dendrites on the neuron Marion Diamond An impoverished environment decreases cell weight, may lead to a loss of cells and the number of dendrites will be reduced (synaptic pruning)

14. If the neural growth is inhibited, then development may not be achieved Does not affect the person with sensitive periods, but critical periods it does Neural plasticity and critical periods

15. Infant States • States of consciousness or levels of awareness that characterize individuals. Some states are: • REM (rapid eye movement) sleep • active sleep without REM • indeterminate sleep • drowsy • inactive alert • active awake • crying

16. Nutrition • Growing research supports nutrition programs for infants which will supply needed nutrients for proper physical, cognitive & emotional development • Breast/Bottle Feeding - While most experts believe that breast-feeding is nutritional better for infant presents problems for working mom • Malnutrition - Infants who are malnourished in their first year may suffer from marasmus wasting away of body tissues caused by severe protein-calorie deficiency leads to severe underdevelopment of child’s cognitive, physical & emotional growth

17. Motor Development Gross and Fine Motor Skills • Skills infant learns through muscle control • Gross skills utilize large muscles for larger motor activities such as moving arms or legs • Fine skills involve more finely turned movements such as finger dexterity.

18. Reflexes of children • Rooting reflex – • You can often stroke the baby’s cheek and see this reflex

19. Eyeblink Reflex • Reflexive blinking that protects baby from bright lights and foreign objects.

20. Sucking Reflex • Babies instinctively begin to suck at objects placed in the mouth.

21. Moro Reflex • When the baby hears a loud noise or their head falls back, they may instinctively extend arms out, arch its back and bring arms toward each other as though they are trying to grab someone.

22. Palmar and Plantar Grasp Reflex • Palmar-Curling of the fingers around an object that touches the palms. • Plantar-Stroke bottom of foot, curl toes

23. Tonic Neck Reflex • The tonic neck reflex, or fencer response, is present at birth • This reflex usually disappears by 4-9 months.

24. Babinski Reflex • Babinski's reflex occurs when the great toe flexes toward the top of the foot and the other toes fan out after the sole of the foot has been firmly stroked • abnormal after the age of 2.

25. Sensory Development • Discerning faces - 1 month old babies appear to be able to distinguish mother’s face from stranger’s as long as they hear the mother’s voice as well • At 3 months, baby appears to distinguish mother from stranger with face alone

26. Sight • Babies are born legally blind with a vision of 20/600 – you need to be no more than 8 inches from their face • By 6 months they are at 20/100 – you need to be at least a few feet away • By 9 months they are at 20/60 – they can see you across the room

27. By age two, vision will be about 20/20 • For the first couple of months, babies will be able to distinguish patterns, but tend to respond to blacks and reds • By 5 or 6 months, babies begin to discern colors • A word about pastels

29. Hearing • By 1 month, babies can distinguish between the smallest variations in sound • By 6 months, they have developed the ability to understand and make all of the sounds necessary for their language structure

30. Touch • Newborns have a well-developed sense of touch and will, over time, come to use this sense a lot • Babies will begin to explore their world using tactile sensations, which is why many of the toys for infants have different textures

31. Smell • 1-day-old infants can distinguish between some smells • 1 ½-month-old infants can distinguish between the smell of their mother and that of a stranger (which is why people tell you to leave the baby with something that has your smell on it)

32. Taste • Newborns appear to prefer the taste of sweet and salty and dislike bitter-tasting things • It has been observed that during pregnancy infants will lick the placenta wall which may help to develop a sense of taste

33. Depth Perception • Visual cliff experiment -

35. Visual Cliff Experiment • 3-month-old babies would have their heartbeat decrease when approaching the “ledge” • 6-month-old babies would have their heartbeat increase when approaching the “ledge” – would not crawl across, although some did when mother prompted them to

36. Depth Perception • Three-dimensional vision does not develop until about 4 months • Brain needs experience to develop 3-D vision • Crawling builds 3-D vision.