Ultrasound: A New View of the Mind

Your doctor may have used ultrasound to inspect your arteries for blockage orto examine your unborn baby. But scientists are now using the technology to trace a more fleeting phenomenon: thought itself. "Most people are familiar with the use of ultrasound to provide pictures of body structure," says Albert Roberts, Ph.D., of Catawba College in North Carolina. "But ultrasound can also be used to monitor the movement of blood through the brain."

Roberts is a pioneer in neurosonography, in which high-frequency sound waves are sent into the brain and reflected by the brain's red blood cells. Unlike magnetic resonance imaging (MRI) and positron emission tomography (PET) scans, which provide only a snapshot of the brain, ultrasound allows researchers to "see" brain activity as it's happening.

Roberts says the technology may one day be used to measure impairment and recovery in the brains of stroke and coma victims, and to track changes in blood flow in response to medications. In Roberts' next research project he will use ultrasound to investigate the effects of a particularly common drug: caffeine.

PHOTO (COLOR): Blood flow velocities to various parts of the brain can be measured by ultrasound.