Brain Imaging Technology

Question 1

fMRI (stands for)

Answer 1

Functional magnetic resonance

Question 2

fMRI (measures)

Answer 2

• Changes in blood flow and oxygenation

- Red indicates high activity, blue is low activity

Question 3

fMRI (how does it work)

Answer 3

• Uses magnetic field, radiofrequency pulses, and a computer to produce detailed pictures of internal body structures
• Blood flow during cognitive activity produces a slight disturbance in its magnetic field due to haemoglobin protein molecule. This concentration in the blood is detected by the fMRI as increased brain activity. The intensity of activity in one region of the brain appears ‘lit up’ on the computer image, indicating the area of greatest activity.
• Shows activity rather than just a still image, enables function to be localised to a specific region of the brain

Question 4

Outline strengths of fMRIs.

Answer 4

• Allows for global researcher triangulation
• Non-invasive

- Produce high resolution images or film

Question 5

Outline limitations of fMRIs.

Answer 5

• Not a natural environment
• Can be anxiety-inducing for a participant which could change the way they respond to a stimulus
• Brain areas can activate for different reasons, eliminating the possibility of establishing a cause and effect relationship between the variables of an experiment and the activity shown on the scans
• Costs limit sample sizes making the reliability of much of the research questionable
• Colour coding can be over-interpreted
• Arifacts issue (structures can be misidentified)
• Lacks ecological validity
• fMRI running cost leads to small sample sizes