Transcript Document

Physical Development:
Brain & Perception
Principles of Physical Development
• Children’s bodies are dynamic systems
• Different parts of the body mature at different rates
• Functioning becomes increasingly differentiated
– Differentiation – an increase from general to more specific
functioning over the course of development
• Functioning becomes more integrated
– Integration – an increasing coordination of body parts over the
course of development
• Every child follows a different growth curve
• Physical development is characterized by both
qualitative and quantitative changes
Teresa M. McDevitt and Jeanne Ellis Ormrod
Child Development and Education, third edition
Copyright ©2007 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
The Brain and Its Development
Neurons in the Brain
Teresa M. McDevitt and Jeanne Ellis Ormrod
Child Development and Education, third edition
Copyright ©2007 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
The Brain and Its Development
• Neuron – cell that
transmits information to
other cells; also called
nerve cell
• Axon – armlike part of a
neuron that sends
information to other
neurons
Teresa M. McDevitt and Jeanne Ellis Ormrod
Child Development and Education, third edition
• Dendrite – branchlike part of a
neuron that receives
information from other neurons
• Synapse – junction between
two neurons
• Glial cell – brain or nervous
system cell that provides
structural or functional support
for one or more neurons
Copyright ©2007 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Structures and Functions
Structure of the Human Brain
Teresa M. McDevitt and Jeanne Ellis Ormrod
Child Development and Education, third edition
Copyright ©2007 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Developmental Changes in the Brain
Developmental Period
Distinctive Neurological Changes
Prenatal
• The primary structures of the brain
emerge
• Neurons are formed
• Cortex matures
Infancy
• Brain forms connections
•Dendrites expand their reach and
complexity
•Synapses grown in density
•Synaptic pruning begins
•Brain searches for stimuli
•Brain becomes differentiated
•Myelinization begins
Teresa M. McDevitt and Jeanne Ellis Ormrod
Child Development and Education, third edition
Copyright ©2007 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Developmental Changes in the Brain
Developmental Period
Distinctive Neurological Changes
Middle Childhood
• Synaptic pruning strengthens connections
•Synaptic pruning in the prefrontal areas
improves memory and attention.
•Myelinization continues to protect neurons
& speed transmission of signals
•New synapses may reflect learning
through experience.
Teresa M. McDevitt and Jeanne Ellis Ormrod
Child Development and Education, third edition
Copyright ©2007 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Developmental Changes in the Brain
Developmental Period
Distinctive Neurological Changes
Adolescence
• Myelination continues to protect
neurons where planning & other
complex thinking occurs
•Brain hemispheres become specialized
•Synaptic pruning continues to improve
memory & attention
•Cortex matures
•Fiber pathways that support speech &
motor functions continue to mature
•Fibers connecting language centers
slow in growth rate
•Analysis of emotional expressions
matures
Teresa M. McDevitt and Jeanne Ellis Ormrod
Child Development and Education, third edition
Copyright ©2007 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Newborn ("neonate") states
1.
2.
3.
Sleep
Crying
Reflexes
Reflexes
•
inborn, automatic response to specific stimulation
•
window to neurological intactness
•
most eventually disappear (eye blinking and sucking
reflex are permanent)
Perceptual abilities
1. Vision
• - least mature of all the senses
• - retina still immature at birth, muscles of the lens weak
• - by 3 mos. infant can focus as well as an adult
• - by age 6 months, adult level visual acuity "20/20 vision"
Infant visual development
Newborn
4 weeks
8 weeks
3 months
6 months
Source: Infant Vision Lab,
Indiana Univ.
Perceptual abilities…
2. Hearing
• prenatal hearing (learning?)
• "Cat in the Hat study"
• hearing of newborns is excellent
LSCP Infant Lab, Paris
• newborns demonstrate preference for Mother's voice and native
language
• as young as 2 months old listen longer to human speech vs.
structurally similar nonspeech sounds
• between 6-8 mos. they filter out sounds that are not important in
their own language
Perceptual abilities…
3. Intermodal perception
• infants coordinate sound and sight; upset if not
synchronous
• by 1 month, infant shows anxiety if see mother but
her voice comes from another place
Imitative ability
• even newborns can imitate
• by 2-3 mos. seems to disappear, but researchers
argue the infant is instead more interested in other
motor skills & social games--the capacity is still
present
Making sense of their world
•
early preference for faces, symmetry, patterns, vertical orientation; by 3
mos. they prefer FACES over similar complex figures
Making sense of their world
• by 3 mos. can distinguish mother's photograph from other
women
• at 4 mos. a perceptual revolution occurs. Probably due to
complex cortical reorganization. Baby can see 3-D,
stereoscopic, locate sounds with precision
According to Piaget, infants do not yet have
ideas or concepts about things (nor a memory
for people or objects if they are absent)...they
only interact with objects at a sensorimotor
level (until 18 mos. or 2 yrs of age).
But recent research suggests otherwise...
What methods can we use to understand what
infants may know if they can’t tell us?
Environmental/Cultural influences?
Most of perceptual ability is considered to be
maturationally-determined
But deprivation can affect motor development
(Example: Iranian orphanage, no toys, left in cribs,
at 2 years still not walking; only 15 percent of
Iranian orphans walked alone by age 3).
Interventions are highly effective (training caregivers
to be responsive and provide stimulation--but not
overstimulate!);
Individual differences?
• Observed individual (and cultural)
differences in motor development are
compatible with a Dynamic Systems
Theory explanation
• Child reorganizes existing motor skills
(e.g., kicking, rocking on all 4s, reaching)
into new patterns of behavior (crawling)
which leads to more effective exploration
skills