There’s a long-standing rough idea that our memory and cognitive abilities peak at the age of 30 and then fall slowly into decline.
About eight years ago, MIT neuroscientists found that different parts of the brain work better at different ages.
The speed that we can process information appears to peak around age 18 or 19, then immediately starts to decline.
Short-term memory continues to improve until around age 25, when it levels off and begins to drop around age 35.
However, our ability to evaluate other people’s emotional states doesn’t peak until the 40 or the 50s.
And crystallised intelligence – the accumulation of facts and knowledge – was once thought to peak in the late 40s. Vocabulary tests revealed, however, the peak happens much later, in your late 60s or early 70s.
So there’s a consolation prize for everybody.
Overall, of course, it’s largely downhill cognitively from middle age and onward.
But not for the super-agers
Super-agers do it differently. Their brains seem to age much slower than average. At the age of 80 or above, their brains look and behave like the brains of people decades younger.
They can recall everyday events and life experiences as well as, or even better, than someone 20 to 30 years younger. They also suffer less cell loss and do better on memory tests.
This was demonstrated in a fascinating 2016 study from Massachusetts General Hospital.
The researchers recruited 81 healthy adults: 40 of them were aged 60 to 80, and 41 were aged 18 to 35.
They were read a list of 16 nouns six times. Twenty minutes later, they were asked to recall as many of the words as possible.
According to a report from Harvard Medical School:
“While 23 of the older participants recalled nine or fewer words, a score considered average for their age group, 17 seniors – the super-agers –could remember 14 words or more.”
Their score was similar to that of the younger participants.
Some neuroscientists believe the ageing brain can benefit from computer cognitive training programs, in much the same way as atrophied muscles can be resurrected at the gym. Image: Ema Ovaskov
Here’s the freaky part
The participants underwent functional magnetic resonance imaging to obtain images of the brain at work.
The researchers found that “some areas of the brain appeared thinner –an indication of cell loss”. This was the case in the older people who had normal test scores, but not in the super-agers.
These particular brain regions are involved in emotion, language, and stress.
They are also responsible for “co-ordinating sensory input into a cohesive experience”.
In other words, it was a part of the brain that made sense of all the random things going on in the world.
The thicker these regions of brain are, “the better a person’s performance on tests of memory and attention, such as the word memorisation test”.
So what makes a super-ager?
One of the co-authors of the paper, neurologist Dr Bradford Dickerson, suggested it’s “embracing new mental challenges [that] may be the key to preserving both brain tissue and brain function”.
He said that although super-agers’ brains show less cell loss than those of their contemporaries, their IQs and educational levels are similar.
What sets them apart might be that they view problem-solving differently, said Dr Dickerson.
“They may approach these tasks as a challenge they can succeed at, in contrast to typical older adults who may give up.”
His colleague and co-author Dr. Lisa Barrett speculated that super-agers “may share a willingness to endure discomfort to master a new skill, like playing a musical instrument or speaking a new language”.
She said super-agers “keep moving out of their comfort zones to gain new areas of expertise”.
A big new study
Most super-ager studies are snapshots. This means that they’re not followed over time, which means brain health isn’t tracked.
New research from the Queen Sofia Foundation Alzheimer Centre, Madrid, examined 64 super-agers and 55 typical older adults for up to a six-year period.
“Typical older adults” were those who performed well on several cognitive tasks but didn’t display super-ager memory ability.
The mean age of the super-agers was 81.9 years. The mean age of the typical older adults was 82.4 years. Most of the participants were women.
During the annual follow-up visits, demographic and lifestyle factors were recorded.
Participants also underwent MRI scans to measure grey matter volume and completed a range of clinical tests. Blood samples were taken to screen for biomarkers for neurodegenerative disease and a key genetic risk factor for Alzheimer’s disease.
A machine learning computer model incorporating 89 demographic, lifestyle, and clinical predictors was used to identify factors associated with super-agers.
Brain scans showed marked differences
The MRI supported previous research and threw up some new clues.
Super-agers exhibited higher grey matter volume in the medial temporal lobe. This region includes a system of structures that are essential for declarative memory (conscious memory for facts and events).
Super-agers also had higher volume of the cholinergic forebrain (plays an important role in learning, memory, and cognitive function), and motor thalamus (implicated in the control of movement).
Longitudinally (over the six years), super-agers also showed slower total grey matter atrophy, particularly within the medial temporal lobe, than did typical older adults.
In other words, cell loss and brain death in this region was slower than typical older participants.
There were similar concentrations of dementia blood biomarkers in super-ager and typical older adult groups. This suggests that super-agers have an inherent “resistance to typical age-related memory loss”.
The take-away findings
Using the machine learning computer model, the authors found “faster movement speed and better mental health were the factors most often associated with super-agers”.
Super-agers performed better in the “Timed Up and Go Test” – a test which gauges people’s mobility – and a finger tapping test that measures fine motor function.
This indicated “they have better mobility, agility, and balance than do typical older adults”.
This observation was made “despite no differences in self-reported exercise levels between super-agers and typical older adults”.
In clinical tests, super-agers scored lower than typical older adults for depression and anxiety.
Previous research suggests “depression and anxiety can impair performance on memory tests in people of all ages, and are risk factors for developing dementia”.
What the researchers say
First author Dr Marta Garo-Pascual, of the Queen Sofia Foundation Alzheimer Centre, Madrid, said:
“We are now closer to solving one of the biggest unanswered questions about super-agers: whether they are truly resistant to age-related memory decline or they have coping mechanisms that help them overcome this decline better than their peers.
“Our findings suggest super-agers are resistant to these processes, though the precise reasons for this are still unclear.”
She said that by looking further into links between super-ageing and movement speed “we may be able to gain important insights into the mechanisms behind the preservation of memory function deep into old age”.