"In the vast majority of people, the left hemisphere is responsible for the expression of language through speech and writing, leaving the right hemisphere mute; however, the right hemisphere is able to communicate through nodding and gestures of the left hand (and singing, in some cases). If a subject is given a coin to hold in her left hand without being able to see it, only the right hemisphere will be aware of it. When asked what she is holding, she will respond that she has no idea, because the left hemisphere (which maintains the ability to communicate verbally) has no awareness of the coin. But if asked to point to a picture of the object she was given, her left hand (controlled by her right hemisphere, the one that knows about the coin) will correctly point to the picture of a coin." - Conscious: A Brief Guide to the Fundamental Mystery of the Mind