This page shows two sets of PET images. Each set includes four PET images labeled A, B, C, and D taken of different areas of the brain, as described on the previous page. Set 1 is always displayed and you can use the previous set and next set buttons to cycle through sets 2 through 6.
Scientists use PET imaging to look at the activity levels in the brain. The PET images have been color-coded by a computer so that the parts of the brain that have the highest activity level are red, areas in yellow have lower activity, followed by green, blue, and then indigo with the lowest activity.
Image A in Set 1 shows many areas in green with some areas in blue. There are several patches of yellow near the outside of the brain. There are only a few small areas of red. Image B in Set 1 also has large areas of green and blue, with patches of yellow near the outside of the brain. Image B has more red patches than Image A does, but they also re relatively small and are around the sides of the brain. Image C has large areas of green and blue. The areas in yellow include a patch at the back of the brain and areas on each side near the front. There are a few small red patches on each side near the front. Image D has large areas of green and blue. The brain areas that are color-coded yellow or red are near the front of the brain and are relatively small.
In Set 2, Image A is similar to Image A in Set 1. In Image B, there is a larger red spot on the right side of the brain about halfway between front and back as compared with Image B in Set 1. Images C and D look similar to the corresponding images in Set 1.
In Set 3, Images, A, C, and D are similar to their counterparts in Set 1. In Image B, there is a bright red area at the back of the brain near the midline.
In Set 4, Images A, B, and D look similar to the corresponding images in Set 1. In Image C, there is a band of red around the front of the brain.
In Set 5, Images A, B, and C look a lot like Images A, B, and C in Set 1. In Image D, four small areas near the back of the brain—two on each side—are color-coded red.
In Set 6, Images B, C, and D are similar to those in Set 1. In Image A, there is a medium-sized area of red on the left side about halfway between front and back.