04
FUNCTIONAL NEUROIMAGING AND DEPRESSION By Tina Liu
Do you know that the activities of the neurons in our brain are constantly fluctuating as we engage in daily activities, no matter if the action is simple or not? Even on occasions when we close our eyes and rest, our brain remains highly active. To measure and map brain activities and improve understanding of certain brain areas, functional magnetic resonance imaging (fMRI) is often applied. Now, let’s find more about this technique. An overview of fMRI The fMRI technique was invented in 1990 by a group at Bell Laboratories led by Seiji Ogawa. It measures brain activity by detecting changes associated with blood flow. When a certain brain region is activated, it calls out for more oxygen. The fMRI will then follow oxygenated blood as it flows through the brain. On the printout of the scan, these oxygenated brain regions will appear to be lit up. The areas scientists can see are smaller than a millimetre cubed, or a voxel (a pixel in three dimensions). The major goal of fMRI data analysis is to detect correlations between brain activation and a task the subject performs during the scan.
