Functional magnetic resonance imaging (fMRI)

• Outline

  • Measures blood flow changes in the brain that occur as a result of neural activity
  • If a particular brain region is more active, there is an increased demand for oxygen, causing increased blood flow in that region
  • Produces a 3-dimensional image showing which regions of the brain are active whilst a participant performs a particular mental task/process
• Strengths

  • Risk-free and non-invasive
  • Produces images with high spatial resolution that are extremely accurate (so provides a clear picture of how brain activity is localised)
• Limitations

  • Expensive compared to other imaging techniques (requires specialist equipment and trained operators) - meaning sample size is often small due to limited availability and funding
  • Participant needs to stay still in order for a clear image to be produced (can be claustrophobic)
  • It is an indirect measure of functioning, measuring blood flow rather than the actual firing of neurons, so there is a 5 second delay between the neurons firing and activity being detected (poor temporal resolution)