This study will examine in healthy individuals and in patients with aphasia (a language disturbance that is usually caused by stroke, brain disease, or injury) which parts of the brain are involved in naming everyday objects. In most people, language and speech originate in the left side of the brain. When this side of the brain is damaged, language function is often impaired. Often, however, function partly recovers, possibly because the right half of the brain takes over some language functions when the left half is injured.