Resting-state fMRI is primarily used to examine?

• A. Brain activity during specific tasks
• B. Brain networks that are active when the person is not performing a task
• C. Structural anatomy
• D. Cerebral blood flow in a disease state

Answer: (B)

Resting-state fMRI focuses on how different brain regions communicate when the brain is not engaged in a task. It tracks spontaneous low-frequency fluctuations in the BOLD signal and finds regions that show synchronized activity, revealing functional networks that operate together during rest, such as the default mode network. This makes it ideal for examining brain networks that are active without task performance. It’s not about which areas light up for a specific task (that’s task-based fMRI), it doesn’t map the brain’s structure (that’s structural imaging), and it’s not a direct measure of cerebral blood flow in disease states (that would be perfusion imaging).