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FOR IMMEDIATE RELEASE
March 30, 1999
Pay Attention, Someone's Watching Your Brain
Scientists at the Medical College of Wisconsin in Milwaukee have made an important discovery in understanding how we pay attention to things, thereby laying the ground work for understanding brain-related disorders of attention. They have made a video of this brain activity and, for the first time, are able to watch the brain in operation as a person mentally shifts attention from one subject to another or when the person is not paying attention at all.
Edgar A. DeYoe, Ph.D., professor of cellular biology, neurobiology and anatomy, and graduate student, Julie Brefczynski, report their findings in the April issue of Nature Neuroscience. The study was supported by the National Institutes of Health (NIH).
"Using your attention is a little bit like playing a video game where things happen so fast, you can't look at each one individually. You have to let your attention pick up the targets without moving your eyes," says Brefczynski.
According to Dr. DeYoe, most people don't notice that they can shift their attention without moving their eyes even though we do this continually all through the day. "For instance, if I'm watching my favorite TV show and someone walks in the room, I can easily tell where they are and even follow their movements without looking away from the TV. I'm shifting my attention rather than my eyes. If a person doesn't move their eyes, you can't tell to what they are paying attention. Now, however, we can peer into their brain and watch it in action. To a limited extent, we can read the person's mind, or at least tell where their attention is focused."
Video games and TV aside, the human brain doesn't have the capacity to comprehend all the detail in a scene at once, nor is it needed. For example, to a person balancing a check book, the important details are the numbers in the column. The color of the table underneath the check book is an unimportant detail even though it is right in front of the person's eyes. The ability to focus attention allows the brain to ignore irrelevant features though it can quickly shift attention from the checkbook to the table and then back again in a split second. In fact that is what normally occurs.
Persons with attention deficit disorder (ADD) may suffer from an impairment of the brain systems that normally allow them to control their attention. Dr. DeYoe suggests that, "By identifying the specific brain activity associated with attention, we've made an important step toward understanding disorders of attention. Now that we have a way of identifying and watching the specific brain activity, we can try to figure out what goes wrong."
The new findings are also important for understanding the relationship between the brain and the mind. "Not only can we shift attention from one thing to another in the scene in front of us, but we can also shift attention from one thought to another. The ability to control and shift our attention is a fundamental part of thinking," says Dr. DeYoe.
To understand the link between the brain and mental activity, the scientists used a specially modified MRI scanner, to take 480 "snapshots" per minute of the brain activity of several volunteers while watching a computerized TV screen.
"To really get a feeling for the brain in action, you need to watch a video of its activity as a person attends to one scene and then another. Once you see it, it's pretty obvious that this is the activity associated with the shifts of attention," says Dr. DeYoe. To back up his claim, he made a short video of the brain activity. It can be viewed or downloaded from the world wide web (www.mcw.edu/cellbio/visionlab) using any popular browser such as Netscape's Navigator or Microsoft's Internet Explorer. The article can be found on the WEB at: neurosci.nature.com
Although researchers have been able to record brain activity in a variety of ways for many years, it has been very difficult until now to identify which portions of the activity are associated with particular mental events such as shifting attention, Dr. DeYoe explains.
The work of the scientists in DeYoe's lab is part of a larger effort at the Medical College of Wisconsin to develop and apply advanced medical imaging technology to the study of the brain. Researchers in the Medical College were at the forefront of the development of a revolutionary technology called functional magnetic resonance imaging or fMRI. Since its development in the early 1990s at the Medical College, scientists here have used the technology to investigate a variety of brain systems and pathologies. These include the study of vision and attention, memory and movement, motivation, drug abuse, language and hearing. Clinically, it has been used to direct brain surgery and to study brain damage in stroke patients. Altogether, Medical College scientists have obtained over $17 million in grant funding from the NIH and other sources.
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