Scanning Techniques Flashcards
fMRI, strengths, weaknesses
- show activity of brain, so what’s active
- S- very accurate and few health risks
- W- very expensive and you have to stay completely still
CT or CAT, strengths and weakness
- used an x-ray bran to produce a picture of the physiology of the brain
- S-provided detailed images of many types of tissue
- W- uses ionising radiation and if exposed to much, it can cause cancer
PET scan, strengths and weakness
- produces a moving picture of brain activity using radioactive glucose injected into bloodstream
- S-Best Option for those scared of getting an infection from medical procedures
- radiation dosage is low
- W- very expensive
Tulving’s Gold Memory Study
Aim:
-investigate difference in processing of episodic and semantic memory
Method:
1)six volunteers (inc him and his wife) were injected with gold radioactive isotope which spread within the bloodstream to the brain
2) Each volunteer lay on a couch and closed their eyes and began thinking about their chosen topic. After 60 seconds, the gold isotope was injected and 7-8 seconds, a rCBF reading was taken.
Results from Tulving’s Gold Memory Study
-three volunteers dropped because of inconsistent results
-brain scans revealed that:
EPISODIC= greater activation in frontal lobes
SEMANTIC= greater activation in parietal and occipital lobe
-semantic and episodic memories produce different activity in different parts of brain
Strengths and weaknesses of Tulving’s Gold Memory Study
S- demonstrated how different areas of the brain are related to cognitive processes
-Used ethical procedures, so asked for their full consent
W- sample is small so cannot be generalised to everyone
-lacks internal validity and there was no way anyone could control what they were thinking
-demand characteristics, so they knew what the aim was and may have worked hard to get the procedure to work
Difference between fMRI and MRI
-MRIs produce a static picture whereas fMRIs show the activity as it occurs
