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?

MRI provides detailed images of brain structures but does not measure brain activity or changes in blood flow. It is primarily used for anatomical imaging rather than functional assessment, making it unsuitable for tracking the activation and deactivation of brain regions in real-time.

CT scans are primarily used for imaging structures and can be useful for identifying abnormalities in the brain but do not provide functional information. Like MRI, CT does not measure brain activity or changes in blood flow, rendering it ineffective for observing activation patterns related to visual stimuli.

EEG measures electrical activity in the brain with high temporal resolution, making it effective for tracking brain responses. However, it has limited spatial resolution and cannot accurately localize activity to specific brain regions like the visual cortex, which is essential for the scenario described.