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Research Methods
Methods of Visualizing the Living Human Brain - Structure
Contrast X-Rays – inject something that absorbs X-rays
Cerebral angiography
Computed Tomography (CT Scan) cross sectional images
CT SCAN When:
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) 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
Positron Emission Tomography (PET) Inject radioactive 2-DG
Functional MRI (fMRI) Visualizing oxygen flow in the
brain
fMRI Vs PET
1. Nothing injected.
2. Provides both structural and functional information in one image
3. Spatial resolution is better than with PET
4. Can create 3-D images of activity over the entire brain
Electroencephalgram (EEG) Measure overall brain activity Epilepsy Sleep Disorders Monitor Brain activity during anethesia
Invasive Physiological Research Methods
Animal research Stereotaxic surgery
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
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 Aspiration lesions – suction Radio-frequency lesions (high frequency
current) – heat destroys tissue Knife cuts – may damage surrounding area
Used to eliminate conduction in a nerve or tract
Cognitive Neuroscience
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
Procedures developed for the investigation of a particular behavioral phenomenon
Traditional conditioning paradigms Skinner boxes Mazes
Autopsies & Brain Damage
