"Humans have always exalted dreams. Pindar of Thebes, the Greek lyric poet, suggested that the soul is more active while dreaming than while awake. He believed that during a dream, the awakened soul may see the future, "an award of joy or sorrow drawing near." So it's no wonder that humans were quick to reserve dreams for people alone; researchers for many years claimed dreams were a property of "higher" minds. But any pet owner who has heard her dog woof or seen his cat twitch during sleep knows that is not true. MIT researchers now know not only that rats dream, but what they dream about. Neurons in the brain fire in distinctive patterns while a rat in a maze performs particular tasks. The researchers repeatedly saw the exact same patterns reproduced while the rats slept--so clearly that they could tell what point in the maze the rat was dreaming about, and whether the animal was running or walking in the dream. The rats' dreams took place in an area of the brain known to be involved with memory, further supporting a notion that one function of dreams is to help an animal remember what it has learned."