“Over the hill” doesn’t exactly describe the people in Dr. Emily Rogalski’s ongoing “SuperAging” study at Northwestern University. If anything, they’re living out their final years on top of the hill. All of them over 80 or 90 years old, these SuperAgers maintain varied lifestyles, but find common ground in the ways that aging has affected — or not affected — their cognitive function.

What Makes A “SuperAger”?

As people grow older, their ability to process information, retain memories, and recognize people and objects fades over time. The brain’s outermost layer, the cortex, gradually begins to thin out. The otherwise thick layer of gray matter that allows for memory and attention withers away, leaving its host in a state of mental decline. But some people don’t see this degradation. Some stay sharp right until death, and it’s these people that Rogalski is interested in investigating.

"We're living long but we're not necessarily living well in our older years,” she said, “and so we hope that the SuperAging study can find factors that are modifiable and that we'll be able to use those to help people live long and live well.”

The SuperAging study has seen several iterations over the years, and Rogalski says that she is still recruiting for this go-around. Fewer than 10 percent of applicants have been accepted. To qualify, Rogalski said, you must be older than 80, willing to donate your brain after death, and pass a rigorous series of mental tests. Participants have their brains scanned during the study and undergo a variety of other medical tests.

The subjects come from a wide range of backgrounds. One is a 96-year-old retired neuroscientist; another is a 92-year-old Holocaust survivor. A third is an 81-year-old pack-a-day smoker who drinks a nightly martini, the Associated Press reports.

How “Super” They Really Are

So far, Rogalski’s study has yielded impressive results. The subjects’ cognitive function rivaled that of the people in their 50s and 60s in the control group. When they were shown 15 words at random, the SuperAgers often remembered at least nine of them. People in their 80s normally recall only a few, Rogalski said.

"These findings are remarkable given the fact that grey matter or brain cell loss is a common part of normal aging," Rogalski said in a statement, following one of her previous SuperAging studies in 2012.

Across the many studies that she has performed, Rogalski has found a consistent theme in her participants. In addition to being more lively and sociable, SuperAgers tend to show greater cortical thickness in their brains, which signals to Rogalski a greater number of remaining brain cells.

"We can't actually count them, but the thickness of the outer cortex of the brain provides an indirect measure of the health of the brain," Rogalski said. "A thicker cortex, suggests a greater number of neurons."

What’s more, the team found that SuperAgers had larger anterior cingulate cortices (ACC) — a small region nestled deep in the brain that controls attention. Many of the SuperAgers’ ACC showed better function than the 50- and 60-year-olds.

SuperAgers showed greater curiosity about the world and maintained an inquisitive outlook.

Questions Without Answers

Still unknown is whether these traits — sociability, greater attention, sustained short-term memory — are products of genetic luck or environmental factors. Research has shown that maintaining a robust collection of social ties can stave off dementia later in life. But the critical conclusions have not yet been made — whether mental decline leads to decreased sociability and liveliness or if it works the other way around. Rogalski hopes the SuperAging study will shed new light on the neurological erosion in Alzheimer’s patients.

"Many scientists study what's wrong with the brain, but maybe we can ultimately help Alzheimer's patients by figuring out what goes right in the brain of SuperAgers,” she said. “What we learn from these healthy brains may inform our strategies for improving quality of life for the elderly and for combatting Alzheimer's disease.”

One woman in Rogalski’s study, a 92-year-old Holocaust survivor named Edith Stern, said her inner youth comes from her vibrancy and a sense of giving back. Stern works in her Chicago retirement home, volunteering at the gift shop and welcoming new residents.

"When you get old, people are mainly interested in themselves. They talk about the doctor, what hurts," she said. "You are not so important that you just concentrate on yourself. You have to think about other people."