Motion Blindness video - Alzheimer's and Vision Problems

For years doctors generally have thought that Alzheimer's patients become lost simply because they forget directions or where they're going. But the Rochester team has found that while Alzheimer's patients certainly do have memory problems, those are separate from the motion blindness that is due to brain damage in a highly sophisticated part of the brain that interprets motion.

"People with Alzheimer's get lost not because they can't remember where they've been, but because they can't see where they're going," says lead author Charles Duffy, a neurologist at the University's Strong Memorial Hospital who made the finding using computer patterns that look like snowflakes rushing toward the viewer. "Many of these patients are basically blind to the kinds of cues most of us absorb unconsciously every day. It's almost like they're walking around with their eyes closed," says Duffy, associate professor of neurology and ophthalmology and a member of the Center for Visual Science. "It's a disorder of perception as well as memory."