Download Presentation - Ch 2 Sections Demo-6-7

Neuroscience and
Behavior
Chapter 2
Neural Network Demo,
Sections 6 and 7, Tools of Discovery
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Neural Network - Demo
Discussion Questions
• Did the network become more accurate at
linking the input to the correct output?
• Is this increased accuracy learning?
• What role did reinforcement play in learning?
• What is Long-Term Potentiation (LTP)?
• How does LTP form the basis for memory?
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Neural Network Demonstration
The Brain and Neural Networks
Interconnected neurons form networks in the
brain. Theses networks are complex and modify
with growth and experience.
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Artificial Neural Networks
• Designed on computers to explore how
natural neural networks can learn
Artificial Neural Network
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Neural Network - Demo
• Set up a learning neural network where
the students are the nodes
• Inputs: see the 6 basic emotions
• Outputs: when motivated to “fire”, they
indicate their designated emotion
• Hidden layer: when excited by input
neurons, they fire to some output neuron
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Neural Network - Demo
• What should the threshold be for firing?
• What threshold will result in the fastest
learning?
• Reinforcement of learning: when output is
correct, that path is strengthened (LTP)
• Long-Term Potentiation: the post-synaptic
neurons become more sensitive to those presynaptic neurons that are exciting it
• LTP becomes memory
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Neural Network Demo
• Post your Notes from the lecture and
discussion.
• Post a Reflective post: what do you think
about this material?
• Go around and read your table group
posts. Rate the Notes with a 6, and the
Reflections with a 10.
• What questions do you have for them?
Discussion #6
How does the endocrine system – the
body’s slower information system –
transmit its messages?
What do the different endocrine glands do?
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hypothalamus
pituitary
thyroid
parathyroids
adrenal
pancreas
gonads
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The Endocrine System
The Endocrine
System is the body’s
“slow” chemical
communication
system.
Communication is
carried out by
hormones
synthesized by a set
of glands.
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Hormones
Hormones are chemicals synthesized by the
endocrine glands that are secreted in the
bloodstream. Hormones affect the brain and many
other tissues of the body.
For example, epinephrine (adrenaline) increases
heart rate, blood pressure, blood sugar and
feelings of excitement during emergency
situations.
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Pituitary Gland
Is called the “master gland.” The anterior pituitary
lobe releases hormones that regulate other glands.
The posterior lobe regulates water and salt
balance.
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Thyroid & Parathyroid Glands
Regulate metabolic and calcium rate.
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Adrenal Glands
Adrenal glands consist of the adrenal medulla and
the cortex. The medulla secretes hormones
(epinephrine and norepinephrine) during stressful
and emotional situations, while the adrenal cortex
regulates salt and carbohydrate metabolism.
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Gonads
Sex glands are located in different places in men
and women. They regulate bodily development
and maintain reproductive organs in adults.
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Discussion #6
• Post your Notes from the lecture and
discussion.
• Post a Reflective post: what do you think
about this material?
• Go around and read your table group
posts. Rate the Notes with a 6, and the
Reflections with a 10.
• What questions do you have for them?
Discussion #7
What are the functions of the brainstem and
its associated structures?
What does each structure do?
• Medulla
• Thalamus
• Reticular formation
• Cerebellum
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The Brain:
Older Brain Structures
The Brainstem is the oldest part of the brain, beginning
where the spinal cord swells and enters the skull. It is
responsible for automatic survival functions.
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Brainstem
The Medulla [muhDUL-uh] is the base of
the brainstem that
controls heartbeat and
breathing.
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Brainstem
The Thalamus [THALuh-muss] is the brain’s
sensory switchboard,
located on top of the
brainstem. It directs
messages to the sensory
areas in the cortex and
transmits replies to the
cerebellum and
medulla.
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Brainstem
Reticular Formation is a
nerve network in the
brainstem that plays an
important role in
controlling arousal.
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Cerebellum
The “little brain”
attached to the rear of
the brainstem.
It helps coordinate
voluntary movements
and balance.
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Discussion #7
• Post your Notes from the lecture and
discussion.
• Post a Reflective post: what do you think
about this material?
• Go around and read your table group
posts. Rate the Notes with a 6, and the
Reflections with a 10.
• What questions do you have for them?
Close-up: The Tools of
Discovery
How do neurobiologists investigate the inner
workings of the brain?
- lesions
- ElectroEncephaloGrams (EEG)
- Positronic Emission Tomography (PET)
- Magnetic Resonance Imaging (MRI)
- functional MRI (fMRI)
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The Brain
Why do neuroscientists create brain lesions?
A brain lesion
experimentally
destroys brain tissue to
study animal behaviors
after such destruction.
Hubel (1990)
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Clinical Observation
Clinical observations have shed light on a
number of brain disorders. How do the brain
structures change when the brain has a
physical or mental disease?
Tom Landers/ Boston Globe
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Electroencephalogram (EEG)
An amplified recording of the electrical waves
sweeping across the brain’s surface, measured
by electrodes placed on the scalp.
AJ Photo/ Photo Researchers, Inc.
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PET Scan
Courtesy of National Brookhaven National Laboratories
PET (Positron Emission
Tomography) scan: a
visual display of brain
activity that detects a
radioactive form of
glucose while the brain
performs a given task.
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PET Scan
Here a PET
scan compares
the brain
activity in a
normal person
to someone
with
Parkinson’s
disease.
(Pre-treatment
and Posttreatment)
MRI Scan
MRI (Magnetic Resonance
Imaging) uses magnetic
fields and radio waves to
produce computergenerated images that
distinguish among
different types of brain
tissue. Top images show
ventricular enlargement in
a schizophrenic patient.
Bottom image taken using
a functional MRI (fMRI)
shows brain regions when
a participant lies.
Both photos from Daniel Weinberger, M.D., CBDB, NIMH
James Salzano/ Salzano Photo
Lucy Reading/ Lucy Illustrations
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Discussion #8
• Post your Notes from the lecture and
discussion.
• Post a Reflective post: what do you think
about this material?
• Go around and read your table group
posts. Rate the Notes with a 6, and the
Reflections with a 10.
• What questions do you have for them?