Functional Magnetic Resonance Imaging
How does it work?
fMRI machines detect changes in blood oxygenation and blood flow that occurs in the brain as a result of neural activity.
When different areas of the brain are active, they require more blood flow (for oxygen)- this is the haemodynamic response.
What does it show?
fMRIs produce 3D images showing which part of the brain is active.
When would you use it?
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for soft tissues (i.e. brain)
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research into internal mental processes (i.e. memory/localisation of function of the brain)
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NO claustrophobia
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NO metal in their bodies (e.g. pacemaker)
Strengths!
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NO radiation (unlike PET scans)
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Non-invasive
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Risk-free
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High spatial resolution (mm)
Weaknesses
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Expensive
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Poor temporal resolution (5-second lag)
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Requires to be very still during scan
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Only measures bloodflow- not individual neuron activity