Psychology MCAT Practice Exam

What is the main purpose of a functional MRI (fMRI) in neuroscience?

1. To measure structural brain changes

2. To detect cancer cells

3. To assess brain activity through blood flow

4. To record electrical activity in the brain

The correct answer is: To assess brain activity through blood flow

The primary purpose of functional MRI (fMRI) in neuroscience is to assess brain activity through changes in blood flow. fMRI capitalizes on the fact that when a specific area of the brain becomes active, it requires more oxygen. The technique detects these changes in blood flow, as oxygen-rich blood has different magnetic properties compared to oxygen-poor blood. By utilizing these differences, fMRI can create detailed images that reflect which parts of the brain are engaged during various tasks or in response to stimuli, thus providing insight into brain function. This capability allows researchers and clinicians to understand how different brain regions contribute to processes such as cognition, emotion, sensory perception, and movement. While the other options describe important medical techniques—like measuring structural changes or recording electrical activity in the brain—none of them accurately represent the primary function of fMRI, which distinctly focuses on capturing dynamic neural processes through blood flow activity.