Which factor is least likely to affect the results and interpretation of a functional MRI in stress research?

• A. The timing of stimulus presentation during the scan
• B. The magnetic field strength of the MRI machine
• C. The color of clothing worn by the participant
• D. The participant's head movement during scanning

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the purpose of functional MRI (fMRI) in stress research, which is to measure brain activity by detecting changes associated with blood flow, often in response to specific stimuli or tasks.
2. Step 2: Consider how the timing of stimulus presentation affects fMRI results, since precise timing is crucial to link brain activity to specific events or stressors during the scan.
3. Step 3: Recognize that the magnetic field strength of the MRI machine influences the quality and resolution of the images, thereby affecting the sensitivity and accuracy of detecting brain activity.
4. Step 4: Acknowledge that participant's head movement during scanning can introduce artifacts and noise, which can distort the data and complicate interpretation of brain activity related to stress.
5. Step 5: Evaluate the factor of the color of clothing worn by the participant, which is unlikely to affect the magnetic field, timing, or brain activity measurements, making it the least likely to influence fMRI results or their interpretation.