Brain Scans Flashcards
Are Brain Scans a considered experimental method?
No - non experimental method
How was the brain studied before scanning techniques were used?
Post - mortem experiments (a corpse brain)
What were the issues with post - mortems?
Could not study actual brain activity due to the brain being inactive
What are the three types of brain scans studied?
MRI, PET and EEG
What does MRI stand for?
Magnetic Resonance Imaging
How does an MRI work?
‣ Magnetic field causes hydrogen atoms in the body to move.
‣ Magnet is switched off, the atoms return to their original positions in the body, producing an electromagnetic signal.
‣ Signals detected and produce a cross-sectional, 2D image.
How long does a MRI take to complete?
15 - 90 minutes
What are advantages of an MRI scan?
‣ Does not use harmful radiation - for patients who must undergo scans several times
‣ Scans give more detailed images - due to strong magnetic field
‣ Allow live brains to be investigated
‣ Allows for objective of brain activity
What are disadvantages of an MRI scan?
‣ Scans may take a long time
‣ May be uncomfortable for patients
‣ Produces 2D images
‣ Expensive technique, therefor not available to all researchers
What does PET stand for?
Positron Emission Tomography
How long does a PET scan tae to complete?
10 - 40 minutes
How does a PET scan work?
‣ Involves injecting radioactive tracer into the body, that is combined with sugar, because the brain uses glucose which can be recorded
‣ Brain contains positrons that move around, which collide with electrons, releases gamma rays
‣ More activity = more positron movement
What are the advantages of a PET scan?
‣ Less claustrophobic.
‣ Minor movements do not affect the scan.
‣ Extremely effective in detecting tumours.
What are the disadvantages of a PET scan?
‣ Tracer is invasive and not appropriate for everyone.
‣ Not advised for pregnant women.
‣ Still claustrophobic for some.
What does EEG stand for?
Electroencephalogram
