Download Overview of the Brain

Chapter 3
The Human Brain
presented by
Isaac Brundage & Charles Small
The Brain Gym
Overview of the Brain
• The brain is a complex organ that is organized and
functions on several levels that can be broken down
into both a micro and macroscopic regions.
• At the microscopic level we have the basic nerve cell,
the neuron, which is interconnected into a network of
neurons that transects, crisscrosses, and connects every
cell and sensory organs to the brain.
• At the macroscopic level these nerve fibers form
clusters in the brain creating distinct regions which after
years of empirical study have been assigned different
functions by scientists over the years.
The Neuron
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The Neuron is a specialized cell that is
designed to transmit information to other
nerve cells, muscle or gland cells and it is the
basic working unit of the brain.
The brain exists because of the structural
and functional properties of these
interconnected neurons. The brain contains
between 1 billion and 100 billion neurons
depending on the species of animal in
question.
The neuron consists of a cell body that
contains the nucleus and cytoplasm,
dendrites, and an axon. The dendrite of one
nerve cell connects with the axon of another.
These contact points are call synapses and
information is transmitted along these nerve
cells as electrical impulses.
Axons are covered with a layer of myelin
sheath which also functions to speed the
transmission of electrical impulses along the
axon.
Neurotransmitters
• Neurotransmitters, for example, serotonin and
dopamine functions as chemical messengers/
regulators that allow the electrical energy that travels
along the nerve cells to cross the different synapses
they encounter.
• Interruptions or deficiencies in these neurotransmitters
often lead to some diseases in humans.
• For example, the degeneration of neutrons that
produce dopamine leads to Parkinson disease while an
excess of dopamine is associated with the
hallucinations that occur with Schizophrenia
(Hockenbury & Hockenbury, 1997).
Building a Brain
• By the third week of gestation, the embryo folds in on itself to form
a trough and then fuses over to form a tube. The head of the tube
becomes the brain and 50% of the tail becomes the spinal cord.
• Neutrons are disseminated throughout the embryo and form
connections with the different cells and organs. And electrical
activity is usually detectable by the third month.
• Normal brain development can be hindered by several factors
including malnutrition, physical injury, and the ingestion of harmful
substances by the mother including alcohol (Gredler, 2009).
Building a Brain
• Following birth the brain undergoes lengthy periods of
development and by age 20 the average weight of the
human brain has increased from 350gms at birth to
1350grams (Blinkov & Gleser, 1968).
• Growth in reference to the brain is the lengthening and
branching of nerve fibers and these occur exuberantly
in the early months and years of life. This is usually
followed by periods of loss and reduction in the
number of synapses to adult levels.
• These growth spurts varies across the cortical regions,
for example, in the visual cortex it begins at age 1 and
is completed by age 10.
Macroscopic Organization
• At the macroscopic level the brain is
divided into subcortical and cortical.
• The subcortical refers to the region
below the cortex and consists of the
thalamus, hypothalamus, amygdala,
and the cerebellum.
• Each of these regions are divided
into twin halves—the left and right
hemispheres of the brain with the
exception of the cerebellum which is
attached to the brain stem.
• These structures are responsible for
low level tasks including processing
sensory information, monitoring
internal states, equilibrium and
rerouting information to name a few.
Structure
Function
Thalamus
Collections of nuclei that each process a particular type of
sensory information (e.g., visual, auditory, tactile). One set of
nuclei integrates this information and communicates with the
prefrontal cortex.
Hypothalamus
Collections of nuclei that each monitor an internal state(e.g.,
food intake, liquid intake, body temperature). One set of
nuclei regulates hormone release from the pituitary gland.
Amygdala
The key entry point for emotional learning; provides rapid,
precognitive, affective assessment of a situation in the context
of survival value (Goldberg, 2001, p.13).
Cerebellum
Responsible for muscle coordination, fine motor movements,
and equilibrium. Research also indicates that it contributes to
complex planning (e.g., Grafman et al., 1992).
Macroscopic Organization
• The learning of new information begins in the
Hippocampus. Hormonal processes influence
the health and death of neurons in the brain.
• Stress and the aging process results in
increased amounts of cortisol which in turns
accelerates cell death in the hippocampus.
This is often manifest itself as Alzheimer’s
disease in the elderly.
Macroscopic Organization
• The neocortex covers the subcortical regions in the
brain and consists of four major lobes that process the
different types of information received from other
parts of the brain.
• Visual information received from the thalamus is
processed in the occipital lobes, auditory information is
processed in the auditory cortex of the temporal lobe,
while the parietal lobes process information about
tactile sensations.
• The frontal lobes consist of the primary motor cortex
which controls voluntary motor movements and the
prefrontal lobes.
Cognitive and Educational Issues
• Linking brain structures and Functions – 3
organizations of the brain that researchers
have linked to functions…..
– Brain centers
– Areas of specialization
– Brain systems
Brain Centers and Areas of
Specialization
• The concept of Brain Centers is the belief that
there are separate brain centers that are
responsible for separate function.
• Areas of Specialization is the belief that the
brain is divided into different areas (like
hemispheres) and each area has a different
function (ex. left brain – analytical; right brain
– creativity)
Brain Systems
• Interconnected unites of the brain each
contribute to systems that are responsible for
separable functions….
– Meaning, no single part of the brain is responsible
for vision, language, social behavior, or other
complex capabilities.
– Or “integrated brain functions”
Misapplications of Some Brain
Research
• Rationale of policymakers for providing
enriched environments for children prior to
age of 3
• The idea that brain development is critical
between ages 3 and 5
– Text states – not supported by neurobiological
data
– “Let your children play and have fun”…Isaac
Brundage
Current Research Methods
• Development of neuroimaging
– Positron Emission Tomography (PET)
– Functional Magnetic Resonance Imaging (fMRI)
• Potential of brain research
– Understanding of cognition and learning
– Life long learning
– Principles of information processing
Administration
• How do I make the connection as a school
level administrator, as a district level
administrator, as a policy maker, as a designer
of curriculum, as a staff or team leader…..?
Class Activities
• Divide into 4 groups – each group will respond
to the following questions:
– Based on the articles on Angel and the
information in the chapter, list ways brain research
can assist when implementing staff development.
Give examples of the types of activities or tasks.
– Based on the articles on Angel and the
information in the chapter, what types of activities
would be included when developing student
curriculum?
Reference
• Blinkov, S.M., & Gleser, I.I. (1968). The human brain in
figures and tables: A quantitative handbook. New
York:
Plenum Press.
• Goldberg, E. (2001.) The executive brain: Frontal lobes and the
civilized mind. New
York: Oxford
University Press.
• Grafman, G. J., Litvan, I., Massaquoi, S., Stewart,
M.,
Sirigu,
A., Hallett, M. (1992). Cognitive planning
deficit in
patients with cerebrellar atrophy.
Neurology, 42(8),
1493-1496.
• Gredler, Margaret. (2009). Learning and instruction: Theory into
practice. New Jersey: Pearson
• Hockenbury, D.H., & Hockenbury, S.E., (1997) Psychology. New
York: Worth.