5. Which of the following best allows a researcher to see activation of the visual cortex while a participant is looking at a photo and then see the activation decrease when the participant stops looking at the photo?
Answer: B
Functional magnetic resonance imaging (fMRI) best allows a researcher to see activation of the visual cortex while a participant is looking at a photo and then see the activation decrease when the participant stops looking at the photo.
fMRI is specifically designed to measure brain activity by detecting changes associated with blood flow, allowing researchers to observe the visual cortex's activation in real-time as participants engage with visual stimuli.
A) Magnetic resonance imaging (MRI)
MRI provides detailed images of the brain's structure but does not measure brain activity or changes in blood flow. Therefore, it cannot show the activation of the visual cortex in response to stimuli or the subsequent decrease in activity.
B) Functional magnetic resonance imaging (fMRI)
fMRI is ideal for this scenario as it measures brain activity by detecting variations in blood flow related to neuronal activation. When a participant looks at a photo, fMRI can show increased activity in the visual cortex, and once the participant stops looking, it can display the decrease in activation, making it the best option.
C) Computed tomography (CT)
CT scans are primarily used for visualizing structural abnormalities in the brain and do not provide functional information about brain activity. Consequently, it is not suitable for observing the activation or deactivation of the visual cortex in response to visual stimuli.
D) Electroencephalography (EEG)
EEG measures electrical activity in the brain through electrodes placed on the scalp. While it can track rapid changes in brain activity, it does not provide spatial resolution to pinpoint activation in specific regions like the visual cortex when looking at a photo, making it less effective than fMRI for this purpose.
Conclusion
Functional magnetic resonance imaging (fMRI) is the only technique among the options that can effectively monitor activation and deactivation of the visual cortex in response to visual stimuli due to its ability to detect changes in blood flow. Other methods like MRI, CT, and EEG lack the functional specificity and spatial resolution required to observe these dynamic changes accurately.