Why a select group of seniors retain their cognitive abilities

December, 2011

Comparison of the brains of octogenarians whose memories match those of middle-aged people reveals important differences between their brains and those of cognitively-normal seniors.

A certain level of mental decline in the senior years is regarded as normal, but some fortunate few don’t suffer from any decline at all. The Northwestern University Super Aging Project has found seniors aged 80+ who match or better the average episodic memory performance of people in their fifties. Comparison of the brains of 12 super-agers, 10 cognitively-normal seniors of similar age, and 14 middle-aged adults (average age 58) now reveals that the brains of super-agers also look like those of the middle-aged. In contrast, brain scans of cognitively average octogenarians show significant thinning of the cortex.

The difference between the brains of super-agers and the others was particularly marked in the anterior cingulate cortex. Indeed, the super agers appeared to have a much thicker left anterior cingulate cortex than the middle-aged group as well. Moreover, the brain of a super-ager who died revealed that, although there were some plaques and tangles (characteristic, in much greater quantities, of Alzheimer’s) in the mediotemporal lobe, there were almost none in the anterior cingulate. (But note an earlier report from the researchers)

Why this region should be of special importance is somewhat mysterious, but the anterior cingulate is part of the attention network, and perhaps it is this role that underlies the superior abilities of these seniors. The anterior cingulate also plays a role error detection and motivation; it will be interesting to see if these attributes are also important.

While the precise reason for the anterior cingulate to be critical to retaining cognitive abilities might be mysterious, the lack of cortical atrophy, and the suggestion that super-agers’ brains have much reduced levels of the sort of pathological damage seen in most older brains, adds weight to the growing evidence that cognitive aging reflects clinical problems, which unfortunately are all too common.

Sadly, there are no obvious lifestyle factors involved here. The super agers don’t have a lifestyle any different from their ‘cognitively average’ counterparts. However, while genetics might be behind these people’s good fortune, that doesn’t mean that lifestyle choices don’t make a big difference to those of us not so genetically fortunate. It seems increasingly clear that for most of us, without ‘super-protective genes’, health problems largely resulting from lifestyle choices are behind much of the damage done to our brains.

It should be emphasized that these unpublished results are preliminary only. This conference presentation reported on data from only 12 of 48 subjects studied.

Reference: 

Harrison, T., Geula, C., Shi, J., Samimi, M., Weintraub, S., Mesulam, M. & Rogalski, E. 2011. Neuroanatomic and pathologic features of cognitive SuperAging. Presented at a poster session at the 2011 Society for Neuroscience conference.

Related News

One important reason for the greater cognitive problems commonly experienced as we age, is our increasing difficulty in ignoring distracting and irrelevant information. But it may be that in some circumstances that propensity can be used to help memory.

A number of studies have found that physical exercise can help delay the onset of dementia, however the ability of exercise to slow the decline once dementia has set in is a more equivocal question. A large new study answers this question in the negative.

Do older adults forget as much as they think, or is it rather that they ‘misremember’?

A Finnish study involving over 1000 older adults suggests that a counselling program can prevent cognitive decline even among those with the Alzheimer’s gene.

A pilot study involving 106 participants of the Rush Memory and Aging Project who had experienced a stroke followed participants for an average of 5.9 years, testing their cognitive function and monitoring their eating habits using food journals.

A small Japanese study has found evidence that those with amnestic mild cognitive impairment (aMCI) show a specific decline in their ability to recognize faces, and this is accompanied by changes in the way they scan faces.

Mild cognitive impairment (

A large study using data from the famous Framingham Heart Study has compared changes in dementia onset over the last three decades. The study found that over time the age of onset has increased while the length of time spent with dementia has decreased.

Data from more than 17,000 healthy people aged 50 and over has revealed that the more regularly participants engaged with word puzzles, the better they performed on tasks assessing attention, reasoning and memory.

Unplanned hospitalizations accelerate cognitive decline in older adults

Data from the Rush Memory and Aging Project has found that emergency and urgent hospitalizations are associated with an increased rate of cognitive decline in older adults.

Pages

Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health news