Peanut butter. It's a regular staple of sandwiches, mouse traps, and the occasional practical joke. But now researchers have another, more serious use for the sticky stuff: detecting early signs of Alzheimer's disease. Alzheimer's affects the front of the brain's temporal lobe---the portion responsible for short-term memory and sense of smell, among other things. Forgetfulness is extremely difficult to measure or track because it is a slow, downward spiral and can easily be chalked up to other causes like aging. But smell is a little more straightforward, which inspired researchers to give a novel nose-based diagnostic test a try.
Armed with a dollop of peanut butter and a wooden 12-inch ruler, researchers measured the distance between a peanut butter sample and the noses of patients (who were closing their eyes and plugging one nostril at a time). Researchers inched the spread closer to patients' noses, little by little, until they ...
