There was no sign of Alzheimer's disease or dementia, two devastating illnesses that until now doctors assumed were inevitable if we lived long enough.

The unnamed woman donated her body to medical science, so doctors have had ample opportunity to study it in far greater detail and depth than they would have had she not made this incredible gift.

"Our observations suggest that, in contrast to general belief, the limits of human cognitive function may extend far beyond the range that is currently enjoyed by most individuals," said lead researcher Gert Holstege, a neuroscientist at the University Medical Center Groningen, in The Netherlands.

LiveScience.com reports that when the woman was 82 years old, she first made the arrangements to donate her body to science following her death. It was at age 111 that she contacted Holstege, quite concerned that the doctors wouldn't want her body because it was too old to be useful to them for research or teaching. Holstege assured her otherwise, saying her body was of particular interest to them because of her advanced age. "She was very enthusiastic about her being important for science," Holstege and his colleagues wrote in the article published in Neurobiology of Aging.

The neuroscientists conducted cognitive exams on the woman when she was 112 and 113 years old. Her mental performance was above average for that of someone age 60 to 75! She showed no signs of dementia or problems with memory or attention. Her autopsy showed no indication of narrowing of the arteries and very few brain abnormalities. LiveScience.com reports that the number of brain cells was similar to that expected in healthy people between 60 and 80 years old and showed no evidence of Alzheimer's disease.