Final answer:
fMRI experiments commonly employ a design that captures changes in brain activity over time, tracking blood flow and oxygen levels to generate a three-dimensional map of active regions. This makes fMRI especially useful for studying brain function and comparing healthy brains to those with disorders.
Step-by-step explanation:
Commonly, functional magnetic resonance imaging (fMRI) experiments are employed to investigate brain activity. Unlike standard MRI techniques that provide static images, fMRI captures changes in brain activity over time. This is accomplished by tracking fluctuations in blood flow and oxygen levels, which correlate with neuronal activity. As a subject performs a task, the fMRI generates a map of the active brain regions, represented in three dimensions to pinpoint exact areas of heightened activity.
Notably, fMRI is based on the same principles as MRI, involving hydrogen nuclei in the water of soft tissues interacting with a magnetic field. The differnece lies in fMRI's ability to measure these interactions continuously, resulting in temporal resolution that reveals metabolic changes as the task progresses. Such functionality is invaluable for comparing brain activity in healthy individuals against those with psychological disorders, helping to elucidate structural and functional brain differences. An fMRI image, such as one showing the activation of the visual cortex in response to visual stimuli, indicates the locations where brain activity is most pronounced during specific tasks or events.