Scientists identify senior 'super' brains
POSTED: Saturday, August 18, 2012 - 12:00am
UPDATED: Saturday, August 18, 2012 - 12:04am
UNITED STATES (CNN) — A group of 80-year-olds is making scientific waves because of an uncanny ability to age gracefully, from a cognitive standpoint. The moniker they've been given by scientists is "SuperAgers," because as they age, their brains seem immune to typical declines in thinking and memory.
"We know that as we age, our cognitive skills decline, and there's also a change in the amount of brain matter," said Emily Rogalski, assistant research professor at the Cognitive Neurology and Alzheimer's Disease Center at Northwestern University's Feinberg School of Medicine. "Then there are these people over 80 who seem particularly sharp and somehow resist changes in memory when they age."
That resistance to memory changes means identifying what makes someone a "SuperAger" is important because of the insight their brains could provide for their cognitive opposites, those who suffer with neurodegenerative diseases like Alzheimer's.
In the study published Thursday, Rogalski and colleagues found something remarkable in the brain scans of so-called "SuperAgers" (defined as people over 80 with sharp memory). The area of the brain housing the most dense concentration of cells (the outer layer of the brain, called the cortex) was quite thick in "Super Agers" - much thicker than you might see in a typical group of 80-year-olds.
The cortex is important for, among other functions, memory.
Among the 12 "SuperAgers," scanned using MRI, cortical thickness was not significantly different than a control group of 14 people in their 50s and 60s.
"So they're over age 80 and their memory performance is at least as good as people in their 50s or 60s," said Rogalski, the study's senior author. "They've been able to get around this process (of cognitive decline) that seems so probable in most individuals."
It's not just the cortex that is so robust among "SuperAgers," but also an area called the anterior cingulate cortex. Researchers were surprised to find that the anterior cingulate is even thicker among "SuperAgers" than the middle-aged control group.
The anterior cingulate, says Rogalski, is important for attention, which in turn can support memory functions. The analogy she uses is rattling off a list of 10 items for a friend to pick up at the grocery store. If that friend is not paying attention to the items on the list, once arriving to the store, he or she might be cruising the aisles with little or no memory of what to pick up.
"SuperAgers may have a keen sense of attention, allowing them to focus better, and that supports their memory," said Rogalski, whose research is published in the Journal of the International Neuropsychological Society.
The question this study could not answer is just what makes "SuperAger" brains so super. The small study group had similar levels of education, and other metrics such as lifestyle and genetics were not examined.
Rogalski says this group will be followed over the long term, and given intermittent brain scans and cognitive exams. The group also gave blood samples at the outset of the study, so that scientists can measure biomarkers that may explain their cognitive prowess.
Closely examining the "SuperAger" brain could be invaluable as scientists continue trying to unlock the mystery of neurodegenerative diseases.