Brain Scanning Techniques fMRI

Question 1

fMRI stands for

Answer 1

Functional magnetic resonance imagery and is more a advanced technique for imaging the brain than the original MRI scanner

Question 2

In what way is fMRI more sophisticated than MRI and how are the images produced different

Answer 2

fMRI gives a colour image, showing activity as well as structure, MRI gives a black and white image similar to X-ray and shows the structure of the brain

Question 3

What does fMRI measure?

Answer 3

Uses magnetic radio-waves to monitor blood flow, measures which parts of the brain are the most active during certain tasks compared to a baseline tasks

Question 4

What principles is it based on

Answer 4

Neurons that are active will be using energy in the form of glucose and oxygen which are directed to the areas requiring it via the bloodstream (haemodynamic response)
The area with the most blood flow to it during a task is the most active

Question 5

fMRI scan therefore used to establish

Answer 5

Localisation of function

Question 6

How does fMRI work.

Answer 6

A powerful magnetic field is applied to the brain
Oxygenated blood has a different magnetic quality than deoxygenated blood
Scanner generates signal called Blood Oxygen Dependent contrast
Reveals which neurons are currently using up most oxygen (most active)
Produces a 3D image showing active parts of the brain in colour

Question 7

Advantage 1 over earlier PET scanning

Non invasive

Answer 7

No insertion of instruments into body like injection use in PET
No exposure to potentially harmful radiation
(Pet scans involve radioactive substances)

Question 8

Advantage 2

It allows smaller areas of the brain to accurately imaged

Answer 8

Better spatial resolution, about 1mm can be imaged 10mm for PET

Question 9

This means that fMRI is used more

Answer 9

Frequently nowadays than PET scans

Question 10

It has contributed to the field of cognitive neuroscience

This is because it has enabled the study of virtually every cognitive process eg

Answer 10

Attention, memory, language and face perception

Question 11

It has also enabled psychologists to identify the neural abnormalities underpinning psychological problems such as

Answer 11

Schizophrenia and autism

Question 12

This means that fMRI has contributed not only to put understanding of LOF but also to

Answer 12

The development of treatments for psychopathology

Question 13

Disadvantages compared to other scanning techniques

1. Is very expensive compared to EEG/ERP

Answer 13

Therefore it is likely trials involve very small sample sizes of participants, could reduce the validity of findings

Question 14

2. Cannot measure brain activity directly unlike EEG/ERP it only measures

Answer 14

Blood flow in the brain, the exact kind of brain activity cannot be determined from this technique

Question 15

3. Has low temporal resolution, there is a time lag of about

Answer 15

5 seconds between the firing of neurons and the image seen on the screen which could lead to bias

Question 16

This means that compared to EEG and ERPs, fMRI could provide a

Answer 16

Less detailed and valid reading of brain activity,