Which neuroimaging method is used to measure brain activity by monitoring changes in blood flow during tasks?

Which neuroimaging method is used to measure brain activity by monitoring changes in blood flow during tasks?

• A. EEG
• B. PET
• C. fMRI
• D. CT

Answer: (C)

Measuring brain activity during tasks relies on a technique that tracks the brain’s blood flow changes as neurons become active. Functional MRI detects the blood-oxygen-level dependent (BOLD) signal, which increases in regions with greater neural activity because active areas receive more blood flow. This provides a map of where brain activity occurs with excellent spatial detail, and it does so without exposing you to radiation. The BOLD signal does not capture electrical activity directly, and there’s a slight delay after neurons fire before the signal rises, reflecting the hemodynamic response. EEG records electrical activity directly from the scalp, offering superb temporal precision but relatively poor spatial localization. PET uses radioactive tracers to measure metabolic processes or blood flow, giving functional information but with lower temporal resolution and involves radioactivity. CT provides structural images, not functional activity. So the method described is functional MRI.

Measuring brain activity during tasks relies on a technique that tracks the brain’s blood flow changes as neurons become active. Functional MRI detects the blood-oxygen-level dependent (BOLD) signal, which increases in regions with greater neural activity because active areas receive more blood flow. This provides a map of where brain activity occurs with excellent spatial detail, and it does so without exposing you to radiation. The BOLD signal does not capture electrical activity directly, and there’s a slight delay after neurons fire before the signal rises, reflecting the hemodynamic response.

EEG records electrical activity directly from the scalp, offering superb temporal precision but relatively poor spatial localization. PET uses radioactive tracers to measure metabolic processes or blood flow, giving functional information but with lower temporal resolution and involves radioactivity. CT provides structural images, not functional activity. So the method described is functional MRI.