Twinkling lights aren't just pretty -- if they're flickering at a specific frequency, they could also treat Alzheimer's disease. A group of researchers have tested the effectiveness of LED lights flashing at 40 hertz as a treatment for Alzheimer's on mice genetically engineered to develop the condition. They found that exposing mice in the early stages of Alzheimer's to the lights for an hour lowered the beta amyloid protein levels in their brains. Beta amyloid accumulates to form plaques that interfere with normal brain function. Further, when they used the same technique on mice already in the advanced stages of the disease for seven days, they found that the method "markedly reduced" the plaques in their brains.