Transcript Chapter 5 The Research Methods of Biopsychology

Research Methods
Methods of Visualizing the Living
Human Brain - Structure
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Contrast X-Rays – inject
something that absorbs X-rays
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Cerebral angiography
Computed Tomography (CT Scan)
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cross sectional images
CT SCAN
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When:
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Find cause of symptoms (confusion, vision
problems, headaches, paralysis)
Trauma
Guidance for biopsy
What: bleeding in brain, clot, enlarged
cavities, fractures, disease, tumors
Magnetic Resonance Imaging
(MRI)
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Produces 3-D images with high spatial
resolution
http://www.med.harvard.edu/AANLIB/cases/caseNA/pb9.htm
Methods of Visualizing the Living
Human Brain - Functional
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Positron Emission
Tomography (PET)
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Inject radioactive 2-DG
Functional MRI (fMRI)
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Visualizing oxygen flow in the
brain
fMRI Vs PET
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Nothing injected.
Provides both structural and functional
information in one image
Spatial resolution is better than with
PET
Can create 3-D images of activity over
the entire brain
Electroencephalgram (EEG)
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Measure overall brain activity
Epilepsy
Sleep Disorders
Monitor Brain activity during anethesia
Invasive Physiological Research
Methods
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Animal research
Stereotaxic surgery
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Lesioning
Electrical stimulation
Invasive recording methods
Manipulating or measuring within the
brain
Copyright © 2006 by Allyn and Bacon
Stereotaxic Surgery
Used to position experimental devices
within the brain
 Stereotaxic atlas – provides coordinates
for locating structures within the brain
 Bregma – a point on the top of the skull
often used as a reference point
 Sterotaxic instrument – used to hold
head steady and guide the device to be
inserted
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Copyright © 2006 by Allyn and Bacon
Lesion Methods
Remove, damage, or destroy a part of
the brain to observe impact on behavior
 Types of lesions
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Aspiration lesions – suction
Radio-frequency lesions (high frequency
current) – heat destroys tissue
Knife cuts – may damage surrounding area
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Used to eliminate conduction in a nerve or tract
Cognitive Neuroscience
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Goal is to identify the parts of the brain that
mediate various constituent cognitive
processes
Paired-image subtraction technique –
compare PET or fMRI images during
several different cognitive tasks
Behavioral Paradigms
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Procedures developed for the
investigation of a particular behavioral
phenomenon
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Traditional conditioning paradigms
Skinner boxes
 Mazes
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Autopsies & Brain Damage