Positron Emission Tomography (PET) PET scans provide color-coded images of the brain’s activity. This example shows the comparison between subjects learning a new language task (left) and performing the language task after it has been well learned (right). Red and yellow colors highlight areas with the highest level of activity, while green and blue colors indicate lower levels of brain activity. As you can see, the process of practicing and learning a new language task involves more and different brain areas before becoming established.
Dr. Marcus E. Raichle, Professor of Radiology & Neurology/Washington University School of Medicine