10. Charles Whitman, the man who climbed to the top of a tower at the University of Texas and started blasting away. He was later found to have a brain tumor near the amygdala, a center for aggression.

9. Phineas Gage, the first well-documented survivor of traumatic brain injury, in 1848. His case convinced the medical profession that the brain was intimately involved in behavior.

8. James Brady, who suffered brain damage during the assassination attempt on Ronald Reagan. His plight brought national attention to brain injury rehabilitation.

7. Ellen G. White, renowned visionary and author of the Seventh Day Adventist Church in the late 1800's, whose visions may have been related to alterations in brain function following traumatic brain injury.

6. Larry Flynt, publisher of "Hustler" magazine, who suffered brain damage following an assassination attempt.

5. Stephen Hawking, astronomer, physicist, author of "A Brief History of Time," and a sufferer of Amyotrophic Lateral Sclerosis (Lou Gehrig's Disease), a brain disorder that paralyzes virtually all skeletal muscle but leaves cognitive function intact.

4. Muhammad Ali, victim of Parkinson's Disease. It is sus- pected that boxing triggered this brain illness, but the evidence is not conclusive.

3. Ken Norton, who fought Muhammad Ali in the 1970's. In interviews today, Norton slurs his speech and sounds "punchy." But in fact, his brain damage was caused by traumatic brain injury suffered in an auto accident.

2. Lou Gebrig, the esteemed New York Yankee baseball player whose name became synonymous with ALS. Gehrig died only a few years after being diagnosed with the disease. The technology that kept Stephen Hawking alive was not available in 1939.

1. Ronald Reagan, was most likely suffering from the early effects of Alzheimer's Disease throughout the length of his second term. He fell back upon overlearned behavior, such as his famed ability to communicate with others, to get by as his cognitive function slowly and inexorably declined over the course of his term of office. The average 90-year-old person has lost 40% of their brain tissue due to age, yet most function remarkably.