Functional magnetic resonance imaging (fMRI) can show the brain at work. Every time we move our little finger or look at a flower, certain regions of the brain are active. And these regions need energy, which reaches the neurons through the blood vessels in the form of oxygen and sugar and is then consumed by the cells. fMRI utilizes this mechanism by visualizing the varying oxygen content of the red blood cells using the so-called “BOLD” (blood oxygen level dependent) effect. A high oxygen content is an indirect indication that the brain cells are active at that location. This method converts the “firing” of the neurons to statistical pictures showing the activation level on a color scale, with yellow symbolizing strong activation and red symbolizing weak activation. If we superimpose the color map on the anatomical MRI image, it is possible to localize neuron activity in a specific anatomical region.