Elderly people with exceptional memory abilities have brains that look decades younger than their actual age, according to a new study.

The study examined the brains of people the researchers call “super-agers,” who despite being age 80 or older, have memory abilities similar to people in their 50s and 60s.

Brain images taken with magnetic resonance imaging (MRI) revealed that the outer layer of the brain, known as the cortex, was about the same size in super-agers as it was in middle-age people.

This finding was remarkable because the cortex — which is important for memory and attention — almost always shrinks with age, the researchers said. In fact, the cortexes of the super-agers were much thicker than the cortexes of a normal group of elderly people in good health, the researchers said.

Figuring out why the brains of super-agers stay so youthful could lead to new therapies that protect against memory loss and Alzheimer's disease, said study researcher Emily Rogalski, an assistant research professor at the Cognitive Neurology and Alzheimer's Disease Center at Northwestern University Feinberg School of Medicine.

Researchers tend to study what goes wrong in the brain to find therapies, but Rogalski said, “perhaps we could learn just as much by looking at what goes right with the brain.”

The study included 12 super-agers (whose average age was 83), 10 elderly people with normal cognition for their age, and 14 middle-age participants.

To qualify as a super-ager, participants had to score about the same as or better than middle-age people on tests of memory. Only about 10 percent of people who expressed interest in being in the study because they thought they had excellent memories actually met the criteria, Rogalski said.

One region of the brain, called the anterior cingulate cortex, was actually bigger in the super-agers than in the middle-aged participants. While this region is not directly involved in memory, it is important in paying attention, Rogalski said.

“Attention is critical for having good memory,” and it may be a keen sense of attention that's supporting the super-agers' exceptional memories, Rogalski said.

The researchers will next collect blood samples from super-agers every 18 months to test whether genetics or other factors play a role in protecting their brains.

In addition, many of the super-agers have agreed to donate their brains to the study upon death. Studying the brain post-mortem will allow researchers to examine the brain cells for features that may provide memory protection, Rogalski said.

The study is published today (Aug. 16) in the Journal of the International Neuropsychological Society.

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