Unit 4 Flashcards
Body growth
-growth is more rapid on infancy than any other period after birth
-infants double weight in 3 months
-infants triple weight by 1 year
-toddlers are half as tall as they will be as adults at about 2 for girls and 2 1/2 for boys
synaptic development
synaptogenesis- the creation of synapses, followed by a period of synaptic pruning= efficiency
Neuroplasticity
brain ability to reorganize neural pathways and connections- plastic or maluable (like mush)
myelinization: reticular formation
-myelin covers axons and insulates improving conductivity (so more communication can develop)
-reticular formation= regulates attention- isnt fully myelinized until the mid-20s
the brain and nervous system development
-most changes happen in the cortex and in the connections
-moving from flexibility to efficiency
newborns reflexs: unlearned, primitive
-newborn is born with a rich set of reflexes, unlearned responses that are triggered by specific stimuli (environment)
-some reflexes may have survival implications. ex-rooting and sucking (adaptive)
-other reflexes (primitive reflexes) may be precursors voluntary motor behaviour (disappear before they start walking)
-may inform about child nervous system
Newborn reflex: babinski
sole of the food is stroked and toes fan out and up. disappears around 12 months
newborn reflex: grasping
object touches the palm and infant grasps it strong for first few months and becomes voluntary by 5 months
newborn reflex: moro
sudden noise or loss of support= arch back and throw arms and legs out and then bring them back in
-disappears after 4 or 5 months
newborn reflex: Plantar
curls toes under when an object is pressed under them
-disappears by 12 months
Newborn reflex: rooting
soft touch on cheek= turn toward touch and open mouth in an attempt to suck
-disappears by 3 months
newborn reflex: tonic neck
infant is placed on back with head to one side=extends arm and legs on that side and flexes opposite arm and leg
-looks like a fencing position and disappears by 4 months
behavioural state
states of consciousness:
- patterns of sleep and wakefulness stablizie with age
–clear nighttime patterns and daytime naps are established
-neonates sleep 80% of the time
-by 8 weeks, babies will begin to “sleep through the night”
-by 6 months, babies are sleeping 13 hours per day
Infant sleep and wakefulness: deep sleep, active sleep, quiet sleep, quiet awake, active awake, crying/fussing
deep sleep: eyes closed, regular breathing, no movement expect occasional startles
active sleep: eyes closed, irregular breathing, small twitches, no gross body movement
quiet awake: eyes open, no major body movement, regular breathing
active awake: eyes open, movements of the head, limbs, and trunk, irregular breathing
crying/ fussing: eyes partly or entirely closed, vigorous diffuse movement with crying or fussing sounds
reflexes and behaviour state: cries and cross-cultural studies
-basic cry signals hunger- rhythmical pattern
-angry cry- louder and more intense
-pain cry- very abrupt onset
cross-culture studies- crying increases until 6 weeks then tapers off
prompts attention to crying in the first three months leads to less crying later
reflexes and behaviour state: colic
-intense daily bouts of crying (3+ hours/ day, 3+ times/ week for >3 weeks with no other cause
-unknown cause
-interventions-family interventions, breastfeeding cessation, probiotics, environment changes
Bones in infant developing
- increase in length of long bones
-changes in number and density are responsible for improved coordination
ossification
-hardening of bones
-begins prenatally
-continues through puberty
muscles in infant developing
-fibres are virtually all present at birth
-initially small and have a high ratio of water to muscle
-high fat content declines to adult levels by age 1
lungs and hear in infant developing
-improvements in lung efficiency and increasing strength of hear muscles= greater stamina by 2
motor skills in infant developing: locomotor
-locomotor skills (gross motor)- crawling (moving from one location to another)
-non-locomotor skills- controlling head movements-
motor skills in infant developing: typical pattern: cephalocaudal, proximodistal
typical pattern:
—cephalocaudal-starts first from head then down to the legs lastly
—proximodistal- begins from centre (like eggs) (spinal cord develops first) and then it develops out from there
—milestones don’t always follow (reach with feet before hands)
motor skills in infant developing: fine motor
-manipulative skills (fine motor control)- use of hands and fingers
milestones of motor development in the first 2 years: month 1
age- month 1
-locomotor skill: stepping reflex
-nonlocomotor skill: lifts head slightly; follows slowly moving object with eyes
-manipulative skills: holds up object if placed in hand
milestones of motor development in the first 2 years: 2-3 months
age- 2-3 months
-nonlocomotor: lifts head up to a 90-degree angle when lying on stomach
-manipulative skills: begins to swipe at objects in sight
milestones of motor development in the first 2 years: 4-6 months
age 4-6 months
-locomotor: rolls over; sits with support; moves on hands and knees (“creeps”)
-nonlocomotor: holds head erect while in sitting position
-manipulative skills: reaches for and grasps objects
milestones of motor development in the first 2 years: 7-9 months
age 7-9 months
-locomotor: sits without support; crawls
-manipulative skills: transfers objects from one hand to the other
milestones of motor development in the first 2 years: 10-12 months
age 10-12 months
-locomotor skills: pulls self up and walks grasping furniture; then walks alone
-nonlocomotor: squats and stoops; plays patty cake
-manipulative skills: shows some signs of hand prefernce; grasps a spoon across palm but had poor aim when moving food to mouth
milestones of motor development in the first 2 years: 13-18 months
age 13-18 months
-locomotor: walks backwars, sideways; runs (14-20 mos)
-nonlocomotor: rolls ball to adult; claps
-manipulative skills; stacks two blocks; puts objects into small container and dumps them out
milestones of motor development in the first 2 years: 19-24 months
age 19-24 months
-locootor skills: walks up and down stairs, two feet per step
-nonlocomotor: jumps with both feet off ground
-manipulative skills: uses spoon to feed self; stacks 4 to 10 blocks
Explaining Motor Skill Development
– Virtually all children follow the same sequence
– Developmentally delayed children just do so more slowly
– Maturation of some kind seems to be occurring
– Experience in normal environments influences motor development
gender differences
Girls are ahead during infancy
* Slight advantage in manipulative skills (self –feeding)
– Boys are typically more active
* Clear preference for rough & tumble play
* More aggressive play than girls by the end of the second year
sensory skills
Newborns & young infants have more sensory capacity than was recently thought
vision: acuity, colour
Newborns respond to light & track moving objects
* Visual Acuity (clarity of vision)
– Smallest pattern that is distinguishable
– Infants at 1 month see at 20 feet what adults see at
200-400 feet
– By 1 year, infant’s visual acuity is the similar to adults
* Eye tracking present early-on
* Colour Vision
– Red, green & blue present by 1 month
– Ability almost identical to an adult’s
Hearing
Auditory Acuity
– Newborns hear nearly as well as adults do
– High-pitched noises need to be loud to be heard
– Can locate the direction of sounds at birth
taste and smell
Newborns react differently to each basic taste as early
as birth
– React to pleasant & unpleasant odors
– Prefer their own & mother’s odor
touch and motion
Touch and Motion
– Best developed of all senses
– Babies react to touch with reflexes & other movements
– Babies react to painful stimuli
perceptual development: innate (nativist) aspects
Newborns have very impressive sensory capabilities
perceptual development methods
Studying perceptual development
– Preference Technique: an experimental technique used specifically for studying infants and toddlers in order to assess how they orient to and understand visual and/or auditory stimuli.
– Habituation/Dishabituation: the diminishing of a physiological or emotional response to a frequently repeated stimulus
– Operant Conditioning: is a learning process where voluntary behaviors are modified by association with the addition of reward or aversive stimuli
perceptual development: experiential
Minimum exposure to sensory stimuli is required for normal development
looking: critical periods
Early Visual Stimulation
– Critical periods of time early on
* A specific quality of visual stimulation is needed to develop
normal visual perception
* Infants born with cataracts show later abnormalities in
detecting position of facial features after corrected (Le Grand
et al., 2001)
looking: depth perception: cues and visual cliff
Depth Perception
– Ability to judge relative distances to objects
– Appears to begin to develop at about age 3 months
– Binocular cues
* Involve both eyes
* Closer object = greater difference in view from each eye
* Eye muscles informs about distance
– Monocular cues
* Input from one eye
* Interposition - one object in front of another
* Linear perspective - lines closer together = farther away
– Kinetic cues
* Motion from objects or the eyes
Depth Perception
– Visual cliff studies – 6-week-olds react with
emotional indicators or interest to depth
differences
– 7-month-olds, show fear of the deep side of the
cliff
– Infants at 4-6 months use retinal disparity
(difference between object images in each eye) to
discern depth
– 5-month-olds use motion & interposition to
perceive depth.
looking: preferences
What Babies Look at
– Babies initially scan for light/dark contrast
– At 2 months, babies scan entire objects to identify things
– Caron and Caron (1981) suggest that by 3 – 4 months
babies can find and pay attention to patterns
* Faces: An example of responding to a complex pattern
– NOT uniquely interesting to infants
– Clearly prefer attractive faces
– Prefer the mother’s face from the earliest hours of life
listening: discriminating speech sounds
At 1 month - discriminate between single syllables
(e.g. pa & ba)
– At 6 months - discriminate between two-syllable
words
– By 3 months - recognize the sound despite who says it
(male or female, young or old)
– At 6 months - distinguish sound contrasts in any
language
* Fades by 1 year
* Correlates with syntaptic growth and pruning
listening: discriminating individual voices
– Newborns – discriminate mother’s voice from
another female
* But, not father’s from another male
– Mother’s voice is preferred
– Babies learn this in utero
licencing: discriminating other sound patterns
– Babies recognize melody patterns by 6 months
intersensory integration
Intersensory Integration
– Coordination of information from 2 or more senses
– Infants attend to intersensory redundancy
* Cross-Modal Transfer
– Transfer of information from one sense to another
* Piaget - these skills did not develop until late in first year
* Gibson & Gibson & others - some of each skill is built in
at birth
* Experience is required for both
