Discuss the use of brain imaging technologies in investigating the relationship between biological factors and behavior
> can see where certain brain processes take place allowing for studies of localization of function in living brains <
Electroencephalogram (EEG): electrodes are placed outside of a persons head in specific locations often using a special cap or helmet so that electrodes are fitted to standardized locations on a skull and can detect changes in electrical activity in the brain. It produces a graphical representation of the activity from each electrode. It is commonly used in sleep research. (Weakness: not sufficiently accurate for localization of function in the brain, electrodes are outside of the skull yet detect activity in the brain, vague ideas of localization but not strong enough to justify conclusions.
Computed Topography (CT): combines computer and X-ray technology that takes photos of the brain from the top, bottom, back, and front sides of the skull and can show the brain at any depth. (Benefit: extremely useful for the structure changes - I.e. tumors or brain damage) (weakness: can only show structural image not activity)
Magnetic Resonance Imaging (MRI): a technique that utilities magnetic fields and radio waves to produce computer generated images that distinguish among different types of soft tissue. The image represents a slice of brain from any angle and can be used to create a three dimensional image. (Weakness: not a natural environment for cognition so question ecological validity)
Functional MRI (fMRI): a technique used to reveal blood flow and brain activity by comparing successive MRI scans. It maps the metabolic changes that indicate brain activity to provide a pictures of which part of the brain is active when certain activities are being performed or certain thoughts or emotions occur.
Positron Emission Topography (PET): monitors glucose metabolism in the brain by being injected with a harmless dose of radioactive glucose. The scans produce colored maps of brain activity and have been used to diagnose abnormalities (I.e. tumors & Alzheimer), compare brain differences between normal and abnormal brains, compare gender differences. (Advantage: can record ongoing activity in the brain)
- - use of colors may exaggerate the different activities of the brain.
- - brain areas activate for different reasons