Transcript The Brain Tools of Behavioral Neuroscience

Essentials of Psychology,
by Saul Kassin
CHAPTER 2:
Behavioral Neuroscience
©2004 Prentice Hall Publishing
Behavioral Neuroscience
The Body’s Communication Networks
The Neuron
The Brain
Prospects for the Future
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Body’s Communication
Networks
The Nervous System
• Central Nervous System(CNS)
– The network of nerves contained within the
brain and spinal cord
• Peripheral Nervous System(PNS)
– The PNS comprises the somatic and
autonomic nervous systems
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Body’s Communication
Networks
Divisions of the Nervous System
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Body’s Communication
Networks
Major Endocrine Glands
• Endocrine system:
Ductless glands that
regulate growth,
reproduction,
metabolism, mood,
and some behavior.
• Hormones: Chemical
messengers secreted
into the bloodstream.
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Neuron
• Neurons
– Nerve cells that serve as the building blocks
of the nervous system
• Sensory Neurons
– Neurons that send signals from the senses,
skin, muscles, and internal organs to the
CNS
• Motor Neurons
– Neurons that transmit commands from the
CNS to the muscles, glands, and organs
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Neuron
The Withdrawal Reflex
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Neuron
The Structure of a Neuron
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Neuron
The Neuron in Action
• Action Potential
– An electrical impulse that surges along an axon,
caused by an influx of positive ions in the
neuron
• Threshold
– The level of stimulation needed to trigger an
action potential
• Neurotransmitters
– Chemical messengers that transmit information
by crossing the synapse from one neuron to
another
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Neuron
How Neurons Communicate
• Impulse releases
neurotransmitter from
axon terminals.
• Neurotransmitter
enters synaptic gap.
• Neurotransmitter
binds to receptors on
the receiving neuron.
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Neuron
Neurotransmitters
Major Neurotransmitters
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Acetylcholine (ACh)
Dopamine
Endorphins
Norepinephrine
Serotonin
Gamma amino butyric acid (GABA)
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
Tools of Behavioral Neuroscience
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Clinical Case Studies
Experimental Interventions
Electrical Recordings
Brain-Imaging Techniques
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
Tools of Behavioral Neuroscience
Electroencephalogram (EEG)
•An instrument
used to measure
electrical activity
in the brain
through electrodes
placed on the scalp
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
Tools of Behavioral Neuroscience
Positron Emission Tomography
– A visual display of brain
activity, as measured by
the amount of glucose
being used
• Radioactive isotopes (small
amounts) are placed in the
blood.
• Sensors detect radioactivity.
• Different tasks show
distinct activity patterns.
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
Tools of Behavioral Neuroscience
Magnetic Resonance Imaging
– A brain-imaging
technique that uses
magnetic fields
and radio waves to
produce, clear
three-dimensional
images
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
Regions of
the Brain
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
Regions of the Brain
The Brainstem
• Medulla
– Vital involuntary
functions
• Pons
– Sleep and arousal
• Reticular formation
– Sleep, arousal,
attention
• Cerebellum
– Motor coordination
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
Regions of the Brain
The Limbic System
• Thalamus
– Sensory relay station
• Amygdala
– Fear, anger, and
aggression
• Hippocampus
– Memory formation
• Hypothalamus
– Regulates glands,
autonomic NS
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
Regions of the Brain
The Cerebral Cortex in Animals
•The outermost
covering of
the brain, largely
responsible
for higher-order
mental processes
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
Regions of the Brain
The Four Lobes of the Cerebral Cortex
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
Regions of the Brain
Within the Lobes of the Cerebral Cortex Are:
• The Somatosensory Cortex
– Receives sensory information
• The Motor Cortex
– Sends impulses to voluntary muscles
• The Association Cortex
– Houses the brain’s higher mental processes
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Somatosensory and Motor Areas
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
Regions of the Brain
Language Processing
• Broca’s Area
– Located in the left
hemisphere, directs the
muscle movements in
speech production
• Wernicke’s Area
– Located in the left
hemisphere, involved in
the comprehension of
language
The brain operates as
an integrated system.
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
The Split Brain
The Corpus Callosum
– A bundle of nerve
fibers that connects
the left and right
hemispheres
• If surgically severed for
treatment of epilepsy,
hemispheres cannot
communicate directly.
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
The Split Brain
• Both eyes send
information to both
hemispheres.
• Images in the right half
of the visual field go to
the left hemisphere.
• Images in the left half of
the visual field go to the
right hemisphere.
Visual Processing
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
The Split Brain
Sperry’s Split-Brain Experiment
• Split-brain subjects could not name objects shown only
to the right hemisphere.
• If asked to select these objects with their left hand, they
succeeded.
• The left hemisphere controls speech, the right does not.
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
The Split Brain
The Talking Left Hemisphere
• Brighter areas
indicate higher
activity levels.
• When hearing
words, for example,
auditory cortex and
Wernicke’s area are
the most active.
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
The Brain
The Split Brain
Neglect Syndrome
• A patient with a stroke
in the right hemisphere
was asked to copy the
drawings.
• Typical of neglect
syndromes, the left side
of the model is almost
completely ignored.
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
Prospects for the Future
The Brain’s Capacity for Growth
& Reorganization
• Plasticity
– A capacity to change as a result of experience
• Richer environments lead to heavier, thicker
brains, more synapses, and better learning.
• The cost of plasticity is the case of the
phantom limb.
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing
Prospects for the Future
The Brain’s Capacity for Growth
& Reorganization
• Neurogenesis
– The production of new brain cells
• Neural Graft
– Technique of transplanting healthy tissue
from the nervous system of one animal into
that of another
Kassin, Essentials of Psychology - ©2004 Prentice Hall Publishing