MCAT® ExamPsychological, Social, and Biological Foundations of BehaviorMedium
A researcher is studying the effects of chronic stress on the brain. They hypothesize that prolonged exposure to high levels of cortisol will lead to a reduction in hippocampal volume. Which neuroimaging technique would be most appropriate to measure hippocampal volume accurately?
- AElectroencephalography (EEG)
- BPositron Emission Tomography (PET)
- CMagnetic Resonance Imaging (MRI)
- DFunctional Magnetic Resonance Imaging (fMRI)
Show answer & explanationAnswer & explanation
Correct answer: C. Magnetic Resonance Imaging (MRI)
MRI provides high-resolution anatomical images of brain structures, making it ideal for accurately measuring the volume of specific brain regions like the hippocampus.
Why the other options are wrong
- A. EEG measures electrical activity in the brain, primarily used for temporal resolution of brain states, not structural volume.
- B. PET measures metabolic activity or receptor binding using radioactive tracers, not structural volume.
- D. fMRI measures changes in blood flow (BOLD signal) to infer brain activity, not structural volume.
Magnetic Resonance Imaging (MRI)
A non-invasive medical imaging technique that uses a strong magnetic field and radio waves to create detailed images of organs and soft tissues within the body.
- Provides high-resolution anatomical images
- Excellent for distinguishing between different soft tissues
- Used to measure brain structure size and identify lesions
- Does not involve ionizing radiation
Memory trick: MRI maps structure, fMRI maps function.