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Slide 1
The Role of Experience
on the Developing Brain
Barb Jackson, Ph.D.
Director, Education & Child Development
Munroe-Meyer Institute
University of Nebraska Medical Center
Omaha, NE USA
The purpose of this presentation is
to provide parents an understanding
of the structure of the brain and
how their experiences with their
young infant/child can affect the
development of the brain.
Slide 2
Slide 3
“The brain is a work in progress,
designed to be adjusted and fine
tuned throughout life.”
Shore, 1997
Recent research has shown us that
the brain truly is a work in progress
and the interactions of young
children in their environment adjust
and fine tune the intricacies of the
brain.
Slide 4
Show a video excerpt that
illustrates a baby and adult
interaction…. Talk about how
they will begin to discover how
interactions influence the
developing brain (optional).
Slide 5
Let’s learn a little bit about brain
development. The brain is part of
the central nervous system that is
contained within the cranium. Here
are a few facts about the
brain……….It weighs 3 pounds. At
birth it is about 1/3 size and by 3 it
is 90% the size of the adult brain.
Brain Development…….
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What is the structure?
How does it work?
Why are we interested in
the brain?
The next section of this presentation
will describe: (a) technologies that
have unveiled new discoveries about
the brain and (b) brain structures
and function, and why we should be
interested in studying this aspect of
the brain.
Slide 6
Advances in Technology
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Slide 7
MRIs
fMRIs
PET Scans
Hearing
Speaking
Seeing
Generating
Words
Rethinking the Brain: Early Childhood Brain Development-Presentation Kit, 1998. For
Full presentation, or research book, Rethinking the Brain, please contact
the Families and Work Institute at www.familiesandwork.org
Slide 8
fMRI
TOMOGRAPHIC
IMAGE
RECONSTRUCTION
TRACER
KINETI
C
MODEL
Rethinking the Brain: Early Childhood Brain DevelopmentPresentation Kit, 1998. For Full presentation, or research
book, Rethinking the Brain, please contact the Families and
Work Institute at www.familiesandwork.org
Advances in technology have really
allowed us to understand the
relationship between experience and
brain development. Two primary
medical advances have supported this
discovery, they include Magnetic
Resonance Imaging (MRI) and PET
scans. MRIs has been available since
the 1980's and are a valuable tool in
obtaining two and three dimensional
images of the brain. This information
is converted into computerized
images representative of the brain
structure.
Positron emission tomography (PET)
was developed in the 1980's. It is
one of the first tools to depict brain
function or metabolism. The images
produced provide information related
to blood flow and energy use in the
brain reflecting neural activity. This
PET shows the brain’s response to a
person reading.
Functional magnetic resonance
imaging (fMRI) is a relatively new
diagnostic tool that allows scientists
to image actual brain activity rather
than the structure alone. These
images are of superior quality than
the PET. Both the fMRI and MRI
are relatively expensive tools.
Slide 9
Neurons:
The Building Blocks of the Brain
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Receive, analyze and
transmit information
Neurons are highly specialized cells
and are the building blocks of the
brain. Their primary function is to
receive, analyze, and transmit
information through the formation of
connections. While there are
different kinds of neurons with
specialized functions, they all have
similar features. The neuron has an
elongated shape with four basic
parts: the soma, an axon, dendrites,
and synapses. In addition, there is a
protective covering on some neuronal
axons called myelin.
The soma (or cell body) contains the
nucleus of the cell. It is responsible
for the regulation of basic cell
properties essential for the health
and survival of the neuron.
The axon is the part of the neuron
that is sometimes called the nerve
fiber. The axon is where information
travels in the form of a nerve impulse
to reach other neurons. Dendrites
are fibrous branch-like protrusions
that extend from the soma and carry
information (in the form of electrical
impulses) toward the cell body.
Whereas a neuron typically has only
one cell body and axon, it may have up
to 600 dendrites.
Myelin is a whitish, fatty material
which insulates and protects the
axons from each other and
significantly increases the
transmission rate of impulses.
A synapse is the space where
communication occurs between the
axon of one neuron and, most
commonly, the dendrite of another
neuron. One neuron can actually have
thousands of these synapses, or
connection sites, with other neurons.
Slide 10
The Child’s Brain Is Unique
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Slide 11
Neurons are not yet fully insulated.
Neurons are still moving into positions.
Synapse development is exploding.
Pattern of Synaptic Development in
the Child’s Developing Brain
Synapse
Development
Birth
6 years
12 years
The child’s brain looks much
different then the adult brain. The
neurons are not fully insulated and
there is rapid increase of synaptic
development. In a newborn the brain
is not fully grown and as a result
there is space in the cranium.
Shaking an infant with their large
head and weak neck muscles results
in broken vessels, swelling, and tears
in the brain tissue due to little to no
myelin.
Look at the pattern of the synapse
development that occurs across time.
Although the actual number of
neurons remain stable….. The
synapses grow rapidly. By the end of
first three years….. The brain
develps twice as many synapses as it
will need, approximately 1,000
trillion. Notice the decline in
synapses by the time the child is 14
years old. Scientist call this
“Pruning.” They suggest that what
synapses are pruned is dependent on
the experiences of the child.
This explains why we have seen a
sudden interest on the emphasis of
the early years. Basically, research
such as Chugani (1987) suggests that
the brain has capacity to change in
the first decade and both positive
and negative experiences can
influence that.
Slide 12
CAUTION!
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There is controversy about Critical
Periods!
REMEMBER, the brain continues to
grow throughout adolescence and
adulthood!
Slide 13
Structure of the Brain
Slide 14
Although there are significant
changes that occur during the early
childhood years there is controversy
about the idea of critical periods and
that all is lost by the time a child is
six. The information that we have
now suggests that the brain
continues to grow and change
throughout adolescence and
adulthood.
Now let’s take a look at the structure
of the brain and the general function
of each part.
Many people think that the toddlers
brain looks like this.
Slide 15
Or that the parent brain looks like
this.
Slide 16
Now let’s begin to explore what the
brain actually looks like and how it
functions. The human brain has many
parts, which function together as an
integrated whole. When learning
about brain structure, it is often
helpful to learn about four major
areas including the cerebral cortex,
diencephalon, cerebellum, and
brainstem. An additional collection
of structures that will be explored is
the limbic system.
Major Structures of the Brain
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Cerebral Cortex
Diencephalon
Cerebellum
Brain Stem
Limbic System
Slide 17
Cerebral Cortex: Frontal Lobe
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Higher intellectual
reasoning
Emotional expression
and regulation, and
Motor movements
The cerebral cortex is what many
individuals popularly think of when
picturing the human brain and it is
responsible for the higher level
cognitive processes associated with
memory, thinking, sensations, vision,
hearing, speech, and personality.
The primary functions related to the
frontal lobe are:
.Higher intellectual reasoning
.Emotional expression and regulation,
and
.Motor movements.
Located in the frontal lobe is the
primary motor cortex, which as the
name implies, is highly involved in
voluntary motor movement. The
Broca’s motor speech area, which is
also in the frontal lobe, is responsible
for mouth movements during speech
production.
Slide 18
Cerebral Cortex: Parietal Lobe
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Sensory Information
To introduce this section have a
quarter and have someone close their
eyes and see if they can guess what
they have. You are now using the
Parietal lobe……..One important
parietal lobe function is the analysis
of body sensory data. Sensory
receptors (e.g., for pain, pressure,
and temperature) send impulses to
this area of the brain. Posterior to
this is an area is called the
somatosensory association area.
This area is highly specialized for
skin sensations and makes
interpretations of the sensations
such as reaching into your pocket and
being able to discern by touch.
Slide 19
Cerebral Cortex: Occipital Lobe
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Visual images
are processed
Slide 20
Cerebral Cortex: Temporal Lobe
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The occipital lobe processes vision
and matures very early.
Specializes in
auditory perception
and language
Analyzes auditory
information that
enable recognition
of whole words
The temporal lobe is an area of the
brain that is responsible for the
detection and analysis of auditory
stimuli. In most persons, the superior
segment of the left hemisphere is
specialized for the comprehension of
language and verbal memory. If
damaged, the ability to understand
spoken or written language may be
impaired, so that one might no longer
be able to glean the conventional
linguistic meaning from stimuli taken
in from the sensory apparatus. If the
right superior portion of the
temporal lobe is damaged,
comprehension of affective language
components may be impaired, so that
the emotional tone in a message will
be missed.
In summary: areas of the cortex
allow the brain to:
*receive, categorize, and interpret
sensory information,
*make rational decisions
*activate behavioral responses
Slide 21
Diencephalon
Hypothalamus
Thalamus
The diencephalon consists of two
parts, the thalamus and
hypothalamus. The thalamus is
concerned with functions associated
with sensation, movement, and
relaying information from one part of
the CNS to another. It receives
sensory information from all senses
except smell (olfactory information
travels directly to the cortex), then
organizes and routes the information
to the cerebrum (where sensation
are ‘felt’). It also helps to associate
sensations with emotions.
The hypothalamus is located inferior
to the thalamus and includes the
pituitary gland. Despite its small size,
it is responsible for a variety of
diverse functions. These include:
*regulation of body rhythms (such as
mental alertness, mood change, sleep
cycles, and hormone secretion); and
*stimulation of several internal
organs in response to emotional
experiences.
Slide 22
Links to Neurological Problems
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Phantom pain
Ringing in the ear
Parkinson’s Disease
Slide 23
Example
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Links affective
experience with
physical reactions….
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Anger
Insomnia
Loss of appetite
Lauerman (2000) suggest that there
are many disorders that are
associated with the thalamus. These
disorders include phantom limb pain,
ringing in the ears, depression, as
well as Parkinson’s disease. Rezai
(2000) has been implanting “brain
pacemakers” into the thalamus of
patients with disorders such as
Parkinson’s disease. The purpose of
the pacemaker is to help reestablish
the rhythms that were disrupted due
to the imbalance of
neurotransmitters. In the case of
Parkinson’s disease, the patients
showed a decrease in hand tremors
when the pacemaker was on.
The hypothalamus helps to translate
affective experiences due to its links
with the higher neocortical
structures. These may include
translating experiences involving
anger, apprehension, and
disappointment into physical
reactions like insomnia, loss of
appetite or deviant hormone patterns
(Pathology, 1990). Many view the
hypothalamus as the bridge between
the body and the mind: the physical
influences on the mind as well as the
mental effects on physical symptoms.
The cerebellum contains more than
half of the brain’s neurons,
suggesting its importance for the
brain’s overall functioning.
Slide 24
Cerebellum
Slide 25
Cerebellum
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Involuntary
movement
Balance
Posture and eye
movements
Long term memory
It is responsible for the coordination
of involuntary (i.e., unconscious)
movement and conditioned reflexes,
which includes muscle tone
regulation, coordination, maintenance
of equilibrium (balance) and posture,
and eye movements. Overall, it helps
to produce smooth coordinated
movements, maintain balance, and
sustain normal postures. The
cerebellum plays an important role in
body movement, and its functioning is
significantly affected by alcohol
(which explains why persons who are
intoxicated often display impaired
coordination and slurred speech).
The brainstem consists of 3 primary
parts, the midbrain, pons and medulla
oblongata.
Slide 26
Brain Stem
Mid-Brain
Pons
Medulla Oblongata
The midbrain is largely made up of
axons, which enable the cerebrum to
communicate with the lower brain
structures. It contains important
motor and sensory nuclei.
Pons is composed primarily of sensory
and motor fiber tracts and serves to
connect the upper and lower CNS
centers.
Medulla Oblongata has the reflex
centers for coughing, vomiting,
swallowing, and sneezing.
In general the limbic system serves
three primary functions including:
Slide 27
Limbic System
Hypothalamus
Fornix
Thalamus
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Olfactory
Bulb
Amygdaloid Nucleus
of Basal Ganglia
Key to emotional
development
Links conscious,
intellectual
functions:
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Cingulate
Gyrus of
Cerebrum
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with the cerebral
cortex
autonomic functions
of brain stem
*Establishing emotion states and
related behavioral drives,
*Linking conscious, intellectual
functions of the cerebral cortex and
autonomic functions of the brain
stem,
*Facilitating memory storage and
retrieval.
Slide 28
Emotional Development
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Emotions are set by the limbic system
and prefrontal lobes
Limbic system forms an emotional
blueprint for later use
Prefrontal lobes regulate emotional
responses
Both lobes are developed and
connected early in life (8-18 months)
Both the limbic system and
prefrontal lobes are related to
emotions. There is a strong
connection between the two areas of
the brain, beginning early in the
infant’s development.
Florida Starting Points Initiative, 1998
Slide 29
Emphasis on the Early Years
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Brain has capacity to change in the first
decade
Enriched environment can increase the
number of synapses
Negative experiences can be more
detrimental
Slide 30
Relationships
ƒ Strong secure
attachments to
nurturing caregiver
provides a
protective biological
function and helps
to buffer later
stress!
Review that the brain is plastic,
especially in the first years of life.
Both positive and negative
experience can affect the number of
synaptic connections that are either
strengthened or pruned.
Research has found that secure
attachment provides a protective
biological function and helps to
buffer later stress. Neuroscience
has provided us with more specific
information on this.
What influences whether synapses
are pruned or not? EXPERIENCE!
Slide 31
Enriched or Deprived:
Environment’s Influence on Brain Development
Use it or Lose it!
Slide 32
Positive Impact of
High Quality Child Care
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Increased IQ scores
Improved rate of brain processing
information
Ramey & Ramey, 1996
Experience plays a role in what
connections are kept and those that
are discarded. Many refer to this as
the “use it or lose it” process.
Signals are strengthened with
experience. As these connections
become established through
experience, they eventually become
exempt from elimination.
Ramey and Ramey (1996) also found
that providing an enriched learning
environment through an intensive,
high quality program for young
children who were at risk for
developmental delay resulted in
significant increases in IQ scores.
PET scans (which measure brain
activity) of these children at 12
years of age, demonstrated that
their brains processed information at
a more efficient rate than those of
the control children. This suggested
that positive behavioral changes (i.e.,
increased IQ scores) were
underscored by an increase in
synaptic connections between brain
cells.
Slide 33
Deprived Environments Negatively
Influence Development
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Decreased IQ
Slower EEG maturation rate
Poverty and cultural disadvantage
were found to be factors in preschool children’s brain activity in
Mexico. Children who were at high
environmental risk demonstrated a
slower EEG maturation rate (Otero,
1996).
Otero, 1996
Slide 34
What happens to a baby who
is stressed??
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Cortisol and
adrenaline are
released in response
to stress
Cortisol reduces #
of synapses
Adrenaline increases
blood pressure and
heartbeat and
tightens muscles
Gunnar, 1996
There is growing concern about what
happens to babies that are stressed.
Neuroscience research has found
that cortisol and adrenaline are
released in response to stress. If
you think about it these important
chemicals are helpful to someone who
is in a stressful situation as they
increase the blood pressure and
heart beat, and tighten your muscles
so that you are more prepared to act.
However, there are negative
responses to chronic stress in which
cortisol is continually released.
Research shows that cortisol reduces
the number of synapses in the brain.
Slide 35
What does research tell us?
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Children exposed to constant stress,
adrenaline does not subside =
hyperaroused state.
Perry, 1993
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Baboons exposed to constant stress had
major shrinkage in their hippocampusrelated to learning and memory.
Sapolshky, 1996
Slide 36
What helps buffer stress?
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Babies who receive nurturing care in
first year, are less likely to respond to
minor stress and produce less cortisol
Suggests that social emotional
environment may help to shape the
regulatory capacities of brain
Dawson, et al., 1992
Slide 37
What are the effects of
depression on a developing brain?
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How do you think a mother’s depression
affects her interaction?
Perry (1993) identified that when
children are exposed to constant
stress, the adrenaline does not
subside. As a result they continue to
be in a hyperaroused state and are
more reactivate to situations. In
addition, animal research showed
that baboons that are exposed to
constant stress had a major
shrinkage in their hypocampus which
is related to learning and memory
(Sapolshky, 1996).
Research is showing us however that
nurturing environments can help
buffer stress. Promising news
suggests that babies who received
nurturing care can buffer the
affects of stress. They are less
likely to respond to minor stress and
produce less cortisol. This has
implications to parent educators as
they are working with families. It is
important to stress strategies that
will help nurture their child. These
will be discussed later in today’s talk.
Have the audience generate how they
think that the mother’s depression
may affect her interaction with the
child.
Slide 38
Depression’s Impact on
Young Infants
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Babies were more withdrawn and
less active
Babies had shorter attention spans and
less motivation to master new tasks
Reduced brain activity (40%) in left
frontal region of the cortex - which is
related to outwardly directed emotions
Greatest period of risk - 6-18 months
Dawson, et al., 1992
Slide 39
Can the impacts of
depression be changed?
ƒ For many babies, once their mothers
were treated for depression, the babies’
brain activity returned to normal.
Dawson, 1992
A study of 27 infants (11-17 months)
found that infants who had mothers
that were depressed showed reduced
left frontal brain activity during
playful interactions with their
mother when compared to infants
with nonsymptomatic mothers.
These findings suggest that infant’s
experience, related to their
emotional environment, influences
brain development and subsequent
behavior (less distress during
separation) (Dawson, Kinger,
Panagitides, Hill, & Spieker, 1992).
The exciting news based on this
research is that for mothers who can
be treated the babies’ brain activity
returned to normal.
Slide 40
What are the implications
for practice?
Do the following exercise: Have
everyone write down 4-5 ideas for
infants and preschoolers- one idea
per sticky. Then have them group
the ideas into themes for each age
group. Have a leader from each
group review the theme with the
whole group. Some ideas are:
Maintain small child/caregiver ratios
Improve our knowledge of children
Respond to children's cues
Engage in language activities
Slide 41
Growth of the Mind
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Consistent, nurturing relationships with
the same caregivers, early in life, are
the cornerstones of emotional and
intellectual competence.
Discuss the importance of
consistency of caregivers and the
implications for child care. For
example, should there be primary
caregivers for each child? Should
child care minimize transition
between age groups?
Greenspan (1992)
Slide 42
Primary Care
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During infancy the most important
relationships are with the primary
caregivers.
Through primary care, the caregivers and
children begin to develop bonds of
comfort, familiarity, trust, and love.
The relationships between children and
caregivers are deepened through the
sharing of daily routines.
It is very important that infants
have a consistent adult figure in child
care settings. This allows for the
development of trust. Consistent
daily routines are also important in
order to provide consistent
expectations for the infant.
Slide 43
Caregiver’s Contribution
to the Relationship
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Positive emotional climate
Sensitivity and responsivity to the
child’s cues
Enriched environmental experiences
Appropriate developmental activities
Slide 44
The Responsive Process
Watch
Act
„ Adapt
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Slide 45
You can make a difference in
a child’s life!
As caregivers, it is important to
provide a positive, nurturing climate
for the children in your care. It is
necessary to be sensitive to the
unique cues of each of the children
and be responsive to those cues,
provide appropriate developmental
activities and enriched environments.
Simply, this is how you can
incorporate a responsive process. Be
an active observer of the child, act
based on the cues of the child, and
adapt your play to meet his emotional
needs and developmental level.
Hopefully today’s presentation has
helped you to understand the
importance of your role in each
child’s development, as well as their
developing brain.
Slide 46
References
Chugani, H. T. (1987). Positron emission tomography study of human brain
functional development. Annals of Neurology, 22 (4): 487-497.
Dawson, G., Kinger, L. G., Panagitides, H., Hill, D. & Spieker, S. (1992). Frontal lobe
activity and affective behavior of infants of mothers with depressive symptoms.
Child Development, 63, 725-737.
Florida Starting Points Initiative (1998). Maximizing Nebraska’s Brain Power: We
need to use it or lose it.
Greenspan, S. (1992). Infancy and Early Childhood: The practice of clinical
assessment and intervention with emotional and developmental challenges.
International Universities Press, Inc., Madison, CT.
Gunnar, M.R. (1996). Quality of care and the buffering of stress physiology: Its
potential in protecting the developing human brain. University of Minnesota
Institute of Child Development.
Slide 47
References, cont.
Otero, G. (1996). Poverty, cultural disadvantage and brain development: A study of
pre-school children in Mexico. Electroencephalography and clinical
neurophysiology, 102, 512-516.
Perry, B.D. (1996). Incubated in terror: Neurodevelopmental factors in the “cycle
of violence.” In J. D. Osofsky (Ed.) Children, youth, and violence: Searching for
solutions. NY: Guildford Press.
Ramey, C. T., and Ramey, S. L. (1996). Prevention of intellectual disabilities: Early
interventions to improve cognitive development. Birmingham: University of
Alabama Civilian International Research Center.
Shore, R. (1997). Rethinking the brain: New insights into early development.
Families and Work Institute. New York, NY.