Monkeys can be tricked into thinking all objects are familiar

Seen it, seen it, seen it, seen it, seen it. Most of us instinctively know whether objects are familiar or unfamiliar. Now we may know how we know. It turns out monkeys have a cluster of neurons in their brains that decides whether or not they have seen objects before. The primary visual area, at the back of the brain, does most of the early work in perceiving an object, especially its physical attributes, such as what direction it is moving.