EVALs fMRI

• Eval points for fMRI

  • S - Avoids the use of radiation unlike PET scans
  • S - Has high spatial resolution
  • S - Provides both structural and functional information
  • W - Poor temporal resolution compared to EEG
  • W - Expensive which will lead to reduced sample sizes compared to EEG
• S - fMRI - avoids the use of radiation unlike PET scans. Therefore it is virtually risk free. Moreover it is non-invasive and so it can be used frequently while still providing a clear image of where brain activity is based
• S - fMRI - high spatial resolution. Since fMRI measures where changes in oxygenated blood flow happen, it is very good at identifying the exact location of neural activity (unlike techniques like EEG). Typically scans can distinguish between the activity of brain regions 3mm apart. However, some high resolution scans can achieve this at a resolution of less than 1mm
• S - fMRI - provides both structural and functional information. It helps us understand change in brain activity during tasks compared to PMA which only gives information about the structure of the brain. Moreover, fMRI can measure deeper regions of the brain e.g. the amygdala vs EEG measure areas near the brain surface only.
• W - fMRI - poor temporal resolution compared to EEG. As fMRI measures changes in blood flow, these changes are much slower than changes in neural activity (it lags behind neural activity by several seconds). This lag can make interpreting the changes in activity caused by an event difficult. Furthermore, quick changes in brain activity, e.g. ones which last 50ms, will not be detected well by fMRI. Therefore fMRI is not an effective technique for identifying when neural activity happens
• W - fMRI - expensive which will lead to reduced sample sizes compared to EEG. Because of the reduced samples sizes (approximately less than 25 participants) this limits the generalisability of the findings about brain activity. Moreover, because fMRI is so expensive, it means fMRI is inaccessible to many researchers