Attention: Why do SuperAgers Maintain Memory and a Thick Cortex?
Posted Sep 20 2012 2:51pm
Are brain aging and cognitive decline ineluctable? Maybe not. Growing research is helping identify “SuperAgers” whose brains at 80+ appear as young as the brains of people in their 50s.
What the latest SuperAgers study found
In a recent paper, researchers defined SuperAgers as people over 80 whose memory performance was at least as good as average 50– to 65-year-old’s performance. 36 participants with similar education levels were involved in the study: 12 SuperAgers who were 80+ and two control groups, one with 10 “normally aging” people of the same age and one with 14 middle-aged adults between 50 and 65.
MRI scans of the participants’ brains were taken to measure the thickness of their cerebral cortex (the outer layer of the brain, aka the grey matter). The SuperAgers’ cortex was thicker than the cortex of the normal group of “normal” 80+ people — whose brains already showed significant atrophy compared to the 50– to 65-year-old healthy group. The SuperAgers’ cortex looked very much like the cortex of participants ages 50 to 65.
Another result surprised the researchers: a region of left anterior cingulate cortex was thicker in the SuperAgers than in both elderly and middle-aged controls.
What does it mean?
Loss of grey matter or brain cells and connections is a common part of normal aging. This study shows that, however, such brain atrophy is not ineluctable. A few older people seem to be protected from the deterioration of memory and brain cells that accompanies aging. Although there may not be that many people who qualify as SuperAgers (only 10% of the people who thought they had great memory actually met the criteria for the study), these results are encouraging. Trying to understand what makes these Super Brains special may help in preventing age-related cognitive impairments and perhaps even in fighting the more severe changes associated with dementia.
So why do these people have such a good memory and such a young cortex? We do not know yet. But there is one important cue: the region of the SuperAgers’ brains which was healthier than both their age-matched peers’ and younger controls’ is important for attention. SuperAgers may thus have a greater attentional capacity, which could help boost their memory and their lifelong learning capacity.
Another question left to be answered is: Are SuperAgers born like that or do they develop such resilient brains throughout their lifespan? A thicker cortex means more brain cells and connections. This could be a given to start with. Or this could be acquired through repeated usage of brain functions, thanks to neuroplasticity.
Could challenging our brains the right way may be enough to transform us into SuperAgers?
Abstract: It is “normal” for old age to be associated with gradual decline in memory and brain mass. However, there are anecdotal reports of individuals who seem immune to age-related memory impairment, but these individuals have not been studied systematically. This study sought to establish that such cognitive SuperAgers exist and to determine if they were also resistant to age-related loss of cortical brain volume. SuperAgers were defined as individuals over age 80 with episodic memory performance at least as good as normative values for 50– to 65-year-olds. Cortical morphometry of the SuperAgers was compared to two cognitively normal cohorts: age-matched elderly and 50– to 65-year-olds. The SuperAgers’ cerebral cortex was significantly thicker than their healthy age-matched peers and displayed no atrophy compared to the 50– to 65-year-old healthy group. Unexpectedly, a region of left anterior cingulate cortex was significantly thicker in the SuperAgers than in both elderly and middle-aged controls. Our findings identify cognitive and neuroanatomical features of a cohort that appears to resist average age-related changes of memory capacity and cortical volume. A better understanding of the underlying factors promoting this potential trajectory of unusually successful aging may provide insight for preventing age-related cognitive impairments or the more severe changes associated with Alzheimer’s disease.
— This article was written by Pascale Michelon, PhD . Dr. Michelon was a Research Scientist at Washington University in Saint Louis were she conducted several projects related to visual processing and memory. She is now an Adjunct Faculty at Washington University, teaches Memory Workshops in the St Louis area and has recently published Max Your Memory .