But the brain is able to make some sense of it all, even though the patient is unaware that he or she is seeing anything. When forced to make a choice, patients typically start out with a success rate of around 50 percent by guessing. Over a period of days, weeks or months, that number goes to 80 or 90 percent, as the brain learns to "see" a new area, and the visual information moves from blindsight to consciousness. Patients eventually become aware of the dots and their movement.
As patients improve, researchers move the dots further and further into what was the patient's blind area, as a way to challenge the brain, to coax it to see a new area.
"Basically, it's exercising the visual part of the brain every day," said Huxlin. "It's very hard work, very grueling. By forcing patients to choose, you're helping the brain re-develop."
The patients in the study did about 300 tests at a time, which translated roughly to sitting in front of a computer for 15 to 30 minutes once or twice a day, every day, for nine to 18 months. It's an exhausting task, especially for someone whose brain is working extra-hard to accomplish it.
Working with Huxlin on the work were Tim Martin, Ph.D., post-doctoral research associate; Kristin Kelly, formerly a technical associate and now a medical student; former graduate student Meghan Riley; neuro-ophthalmologist Deborah Friedman, M.D.; neurologist W. Scott Burgin, M.D.; and Mary Hayhoe, Ph.D., formerly of the Department of Brain and Cognitive Sciences at the
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