In the context of AP Psychology, what does a PET scan primarily measure in the brain?

• A. It measures changes in blood oxygen levels to show brain activity.
• B. It measures the brain's metabolic activity by detecting the use of radioactive glucose.
• C. It records the brain's electrical activity through electrodes placed on the scalp.
• D. It provides detailed images of brain structure using magnetic fields and radio waves.

Answer: (B)

Verified step by step guidance

1. Understand that a PET scan, or Positron Emission Tomography scan, is a neuroimaging technique used in psychology to study brain function.
2. Recognize that PET scans work by detecting radioactive tracers, which are often attached to glucose molecules, because glucose is the brain's primary source of energy.
3. Know that when the brain areas are more active, they consume more glucose, so the PET scan measures the brain's metabolic activity by tracking the radioactive glucose uptake.
4. Differentiate PET scans from other brain imaging techniques: for example, fMRI measures blood oxygen levels, EEG records electrical activity, and MRI provides detailed structural images.
5. Conclude that the primary measurement of a PET scan is the brain's metabolic activity, indicated by the detection of radioactive glucose usage in different brain regions.