Transcript File

Chapter 4
Physical Development
in Infancy and Toddlerhood
Learning Goals
• Describe major changes in body growth over the
first two years
• Identify alerts and milestones
• Describe brain development
• Organization of sleep and wakefulness change
over the first two years.
• Infant learning capacities
• Factors that influence motor progress
• Changes in hearing, depth and pattern perception,
and intermodal
Body Growth
 Height increases 50%
by age 1, 75% by age 2
 Weight doubles by 5
months, triples by 1 year
 Individual and group
differences in size and
rate of growth
 Fastest growth than
any time during their
lifespan.
© Monkey Business Images/Shutterstock
Individual and Group
Differences in Growth
 Group differences:
 male/female
 ethnic
 Individual differences
 Skeletal age: best
estimate of physical
maturity
© Oksana Kuzmina/Shutterstock
Growth Trends
Changes in Body Proportions
Cephalocaudal
 “Head to tail”
 Lower part of
body grows later
than the head
Proximodistal
 “Near to far”
 Extremities grow
later than head,
chest, and trunk
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http://drhart.net/clinic/forms/Denver%20II%20Developmental%20Mil
estones.pdf
Neurons and Their Connective
Fibers
Neurons
Nerve cells that store and
transmit information
Synapses
Tiny gaps where fibers from
different neurons come together
but do not touch
Neurotransmitters
Chemicals that are released by
neurons and cross the synapse
Synaptic Pruning and
Myelination
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What is synaptic pruning?
https://youtu.be/rxPT78F_ZVE
What is myelination?
Why is stimulation vital to their survival?
What visual image would you use to
describe this process?
Regions of the Cerebral Cortex
Figure 4.4
Brain Plasticity
 At birth, hemispheres have already
begun to specialize
 Highly plastic cerebral cortex has
high capacity for learning
 If part of cortex is damaged, other
areas can take over its tasks
 Older children and adults retain
some plasticity, but less than in
young children
Sensitive Periods in
Brain Development
Appropriate stimulation
is vital for brain growth
 Experience-expectant
growth: depends on
ordinary experiences
 Experience-dependent growth:
additional growth resulting from specific
learning experiences
© Andy Lim/Shutterstock
Prefrontal Cortex
 Region of the cerebral cortex responsible
for thought, especially:
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consciousness
inhibition of impulses
integration of information
use of memory, reasoning, planning, and
problem-solving strategies
 Undergoes rapid growth in the preschool
and school years, and in adolescence
Lateralization of the
Cerebral Cortex
Left Hemisphere
 Verbal abilities
 Positive emotion
 Sequential, analytic
processing
Right Hemisphere
 Spatial abilities
 Negative emotion
 Holistic, integrative
processing
Changing States of Arousal
 Sleep–wake pattern moves to night–day
schedule during first year
 By age 2, total sleep time declines from
18 to 12 hours per day
 Sleep patterns are
affected by social
environment,
cultural values
 Not until middle of the first year is the
secretion of melatonin, a hormone
within the brain
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Cultural Variation in Infant
Sleeping
 Cultures differ on sleeping arrangements
 Page 99
 Do you have an opinion on sleeping arrangements?
 American Academy of Pediatrics has issued a
controversial warning about infant bedsharing and
SIDs.
 “By 6 months, a child who regularly sleeps in their
parent’s room may feel uneasy sleeping anywhere
else.” see page 99
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Poll everywhere
Influences on Early Growth
 Heredity
 Nutrition:
 Activity Pros vs Cons
 breastfeeding
vs. bottle-feeding
 risks of overfeeding
© stefanolunardi/Shutterstock
 Malnutrition
The Steps of
Classical Conditioning
Figure 4.5
Malnutrition
Type
Consequences
Marasmus (diet low in
all essential nutrients)
Lasting physical damage;
learning and behavioral
effects; risk of death
Kwashiorkor (diet
very low in protein)
Lasting physical damage;
learning and behavioral
effects
Food insecurity
Effects on physical
growth; learning problems
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Imitation
 Infants are born with
primitive ability to
imitate
 Mirror neurons provide
biological explanation
 Powerful means of
learning
© Seleznev Oleg/Shutterstock
Motor Development
Sequence and Trends
© S.Borisov/Shutterstock
 Gross-motor development:
crawling, standing, walking
 Fine-motor development:
reaching, grasping
 Sequence is fairly uniform
 Large individual differences
in rate of motor progress
Motor Skills as
Dynamic Systems
 Mastery involves acquiring increasingly
complex systems of action with each skill
 Each new skill is joint product of
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central nervous system development
the body’s movement capacity
the child’s goals
environmental supports for the skill
http://abavtooldev.pearsoncmg.com/VPsms/si
mpleviewer.php?projectID=BerkICA7&clipID=
010_motor_dev_infancy.flv&ui=2
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Milestones of
Reaching and Grasping
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Activity
 Put flashcards in order of 90% gross development
 These are considered milestones
Developments in Hearing
4–7 months
Sense of musical phrasing
6–7 months
Distinguishes musical tunes based
on variations in rhythmic patterns
6–8 months
“Screens out” sounds not
used in native language
6–12 months
Detects sound regularities
in human speech
7–9 months
Begins to divide speech stream
into wordlike units
Visual Development
 Supported by rapid
maturation of eyes and
visual centers in brain
 Improvements:
© Payless Images/Shutterstock
 2 months: focus
 4 months: color vision
 6 months: acuity,
scanning, and tracking
 6–7 months: depth
perception
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Milestones in
Depth Perception
3–4 weeks
Sensitivity to motion cues
2–3 months
Sensitivity to binocular depth cues
5–7 months
Sensitivity to pictorial depth cues
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Milestones in
Pattern Perception
2
months
Becomes sensitive to contrast in complex
patterns; prefers them to simple patterns
2–3
months
Thoroughly explores a pattern’s features,
pausing briefly to look at each part
3–4
months
Detects pattern organization, integrating
pattern parts into organized whole
12
months
Detects familiar objects represented
by incomplete drawings
Milestones in Face
Perception
Birth–
1 month
Prefers simple facelike pattern to other stimuli
2–4
months
Prefers complex facial pattern
to other complex stimulus arrangements
Prefers mother’s detailed facial
features to another woman’s
3 months
Distinguishes features of different faces
5–12
months
Perceives emotional expressions
on faces as meaningful wholes
Milestones in
Intermodal Perception
Birth
Perceives amodal sensory properties
3–4
months
Matches faces with voices on basis of
lip–voice synchrony, emotional expression,
and speaker’s age and gender
4–6
months
Perceives and remembers unique
face–voice pairings of unfamiliar adults
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Milestone vs Alerts
 Using CDC alerts and milestones your group is going to
list milestones for the first two years and then alerts.
 You will develop questions to quiz the group
 What would you tell a parent whose child is not
developing a milestone?
 What would you do if you saw an alert?
Safety Issues
Safety issues
Use of proper clothing for play and sleep
Use of proper safety restraints in motor vehicles
Stranger safety
Water safety
Poisoning
Vary among age groups
 Nonfatal suffocation rates were highest for those less than 1 year
of age.
 Rates for fires or burns, and drowning were highest for children 4
years and younger.
 Children 1 to 4 years of age had the highest rates of nonfatal falls
and poisoning.
 Injury rates related to motor vehicles was highest in children 15
to 19 years of age.
 Source CDC
Leading Cause of Death in
Children across lifespans
 Injuries
 Motor Vechicle Accidents
 http://www.cdc.gov/MotorVehicleSafety/Child_Passenger_
Safety/CPS-Factsheet.html
INJURY PREVENTION
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Car seats which one do I
use?????
 Infant rear facing
 Toddler
 Booster