People usually find it easier to see things when they are big and bright, but there are occasionally exceptions. One example concerns moving objects: when they are small, we can identify their direction of motion easily. But this becomes much more difficult for larger objects. This phenomenon is known as spatial suppression http://www.nature.com/nature/journal/v424/n6946/full/nature01800.html.
Of all the neurodegenerative diseases, Alzheimer’s disease (AD) stands as the most common worldwide. While the onset is complex in nature, a hallmark sign of illness is the accumulation of a particular peptide in the brain, known as amyloid beta (Aβ) (http://www.jci.org/articles/view/25100). When present, the molecule can aggregate to form plaques and also interact with cells in the brain leading to altered signalling and function.