So far, brains from hundreds of people who donated their bodies to science have been carefully turned into microthin slices of tissue and photographed by digital cameras. The images reveal chemistry as well as cellular and microscopic organization of the brain. Researchers can use mathematical manipulations to restore the natural shape of slices squashed by cutting. MRI scanners use magnetic fields and radio pulses to make images. Eventually, the researchers will incorporate PET scans showing brain activity when research subjects are asked to carry out specific tasks.
PET scanners use radio waves to measure how chemicals move through brain tissue.
The brain mapping project is part of the larger Human Brain Project, coordinated through the National Institute of Mental Health. Other Southern California institutions are involved in the brain project. The California Institute of Technology in Pasadena is doing high-field MRI scans of animal brains with an instrument about seven times stronger than those commonly found in hospitals.