Greebles test could spot Alzheimer's disease

If you want to know whether you're at risk of Alzheimer's disease, taking this test could help you. Those unable to tell which character is the odd one out could well be at risk of the devastating illness. Known as Greebles, the little purple characters have been designed by scientists in their ongoing quest for a cure. A study found those at genetic risk of the disease struggle to distinguish a subtle difference in one of the images. But they may be unaware of their likelihood as they are still able to detect minor changes in people's faces, objects and scenes.