Cognitive Reserve & Mental Stimulation

Cognitive decline is less in those who engage more frequently in cognitively stimulating activities.

Activities that keep you actively searching for words (such as scrabble and crosswords) may help reduce those tip-of-the-tongue experiences where particular words cannot quite be recalled.

Cognitive training programs can reverse cognitive impairment in many seniors

A study involving 39 older adults has found that those randomly assigned to a “high-challenge” group showed improved cognitive performance and more efficient brain activity compared with those assigned to a low-challenge group, or a control group.

The high-challenge group spent at least 15 hours a week for 14 weeks learning progressively more difficult skills in digital photography, quilting, or a combination of both. The low-challenge group met to socialize and engage in activities related to subjects such as travel and cooking. The placebo group engaged in low-demand cognitive tasks such as listening to music, playing simple games, or watching classic movies.

The high-challenge group demonstrated increased neural efficiency in judging words, shown by lowered brain activity when word judgments were easy and increasing activity when they became hard. This is a pattern of response typical of young adults, and was not seen in them before the intervention, or among those in the other groups. To some extent, these changes were still seen a year later.

Moreover, there was a dose-dependent effect — meaning, those who spent more time engaging in the high-challenge activities showed the greatest brain changes.

So did those who were oldest, perhaps because their brains were most in need, perhaps because they were the most disengaged. Most likely, perhaps, because both of these were true.

The bottom line, though, is that, while all mental stimulation is good in terms of building cognitive reserve, actively learning, and really pushing yourself, is what you need to get to, or keep at, the top of your game.

Data from 2,800 participants (aged 65+) in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study has revealed that one type of cognitive training benefits less-educated people more than it does the more-educated.

While the effects of reasoning and memory training did not differ as a function of how much education the individual had, those older adults with less than a complete high school education experienced a 50% greater benefit from speed of information processing training than college graduates. This advantage was maintained for three years after the end of the training.

The training involved ten 60 to 75-minute sessions over six weeks that focused on visual search and processing information in shorter and shorter times.

Both reasoning and information processing speed training resulted in improved targeted cognitive abilities for 10 years among participants, but memory training did not. Memory training focused on mnemonic strategies for remembering lists and sequences of items, text material, and main ideas and details of stories and other text-based information. Reasoning training focused on improving the ability to solve problems containing a serial pattern.

The researchers speculate that speed of information processing training might help those with less than 12 years of education, who are at greater risk of dementia, close the gap between them and those with more education.

The training modules have been translated into online games delivered by Posit Science.

Less educated study participants were slightly older, less likely to be married, more likely to be African-American, and more likely to have hypertension or diabetes as well as heart disease than the more educated older adults.

While it’s well-established that chronic stress has all sorts of harmful effects, including on memory and cognition, the judgment on brief bouts of acute stress has been more equivocal. There is a certain amount of evidence that brief amounts of stress can be stimulating rather than harmful, and perhaps even necessary if we are to reach our full potential.

A recent rat study has found that brief stressful events caused stem cells in the hippocampus to proliferate into new neurons that, when mature two weeks later, improved the rats’ mental performance. But note that their performance took time to improve — there was no benefit only two days after.

Chronic stress also impacts the creation of new neurons, but in the opposite direction — it suppresses neurogenesis. The difference probably lies in how long the stress hormones remain elevated. Previous research modeling PTSD in rodents has found that severity and length are crucial variables.

This new study shows that higher levels of stress hormone initially increase the production of new neurons in response to the release of a protein, fibroblast growth factor 2 (FGF2), but these need time to develop. Interestingly, FGF2 deficiency has been linked to depression, and depression is also known to be associated with a reduction in neurogenesis.

[3379] Kirby ED, Muroy SE, Sun WG, Covarrubias D, Leong MJ, Barchas LA, Kaufer D. Acute stress enhances adult rat hippocampal neurogenesis and activation of newborn neurons via secreted astrocytic FGF2. eLife [Internet]. 2013 ;2:e00362 - e00362. Available from:

Full text available at

A new study adds more support to the idea that the increasing difficulty in learning new information and skills that most of us experience as we age is not down to any difficulty in acquiring new information, but rests on the interference from all the old information.

Memory is about strengthening some connections and weakening others. A vital player in this process of synaptic plasticity is the NMDA receptor in the hippocampus. This glutamate receptor has two subunits (NR2A and NR2B), whose ratio changes as the brain develops. Children have higher ratios of NR2B, which lengthens the time neurons talk to each other, enabling them to make stronger connections, thus optimizing learning. After puberty, the ratio shifts, so there is more NR2A.

Of course, there are many other changes in the aging brain, so it’s been difficult to disentangle the effects of this changing ratio from other changes. This new study genetically modified mice to have more NR2A and less NR2B (reflecting the ratio typical of older humans), thus avoiding the other confounds.

To the researchers’ surprise, the mice were found to be still good at making strong connections (‘long-term potentiation’ - LTP), but instead had an impaired ability to weaken existing connections (‘long-term depression’ - LTD). This produces too much noise (bear in mind that each neuron averages 3,000 potential points of contact (i.e., synapses), and you will see the importance of turning down the noise!).

Interestingly, LTD responses were only abolished within a particular frequency range (3-5 Hz), and didn’t affect 1Hz-induced LTD (or 100Hz-induced LTP). Moreover, while the mice showed impaired long-term learning, their short-term memory was unaffected. The researchers suggest that these particular LTD responses are critical for ‘post-learning information sculpting’, which they suggest is a step (hitherto unknown) in the consolidation process. This step, they postulate, involves modifying the new information to fit in with existing networks of knowledge.

Previous work by these researchers has found that mice genetically modified to have an excess of NR2B became ‘super-learners’. Until now, the emphasis in learning and memory has always been on long-term potentiation, and the role (if any) of long-term depression has been much less clear. These results point to the importance of both these processes in sculpting learning and memory.

The findings also seem to fit in with the idea that a major cause of age-related cognitive decline is the failure to inhibit unwanted information, and confirm the importance of keeping your mind actively engaged and learning, because this ratio is also affected by experience.

In my last report, I discussed a finding that intensive foreign language learning ‘grew’ the size of certain brain regions. This growth reflects gray matter increase. Another recent study looks at a different aspect: white matter.

In the study, monthly brain scans were taken of 27 college students, of whom 11 were taking an intensive nine-month Chinese language course. These brain scans were specifically aimed at tracking white matter changes in the students’ brains.

Significant changes were indeed observed in the brains of the language learners. To the researchers’ surprise, however, the biggest changes were observed in an area not previously considered part of the language network: the white matter tracts that cross the corpus callosum, the main bridge between the hemispheres. (I’m not quite sure why they were surprised, since a previous study had found that bilinguals showed higher white matter integrity in the corpus callosum.)

Significant changes were also observed within the left-hemisphere language network and in the right temporal lobe. The rate of increase in white matter was linear, showing a steady progression with each passing month.

The researchers suggest that plasticity in the adult brain may differ from that seen in children’s brains. While children’s brains change mainly through the pruning of unwanted connections and the death of unwanted cells, adult brains may rely mainly on neurogenesis and myelinogenesis.

The growth of new myelin is a process that is still largely mysterious, but it’s suggested that activity at the axons (the extensions of neurons that carry the electrical signals) might trigger increases in the size, density, or number of oligodendrocytes (the cells responsible for the myelin sheaths). This process is thought to be mediated by astrocytes, and in recent years we have begun to realize that astrocytes, long regarded as mere ‘support cells’, are in fact quite important for learning and memory. Just how important is something researchers are still working on.

The finding of changes between the frontal hemispheres and caudate nuclei is consistent with a previously-expressed idea that language learning requires the development of a network to control switching between languages.

Does the development of such a network enhance the task-switching facility in working memory? Previous research has found that bilinguals tend to have better executive control than monolinguals, and it has been suggested that the experience of managing two (or more) languages reorganizes certain brain networks, creating a more effective basis for executive control.

As in the previous study, the language studied was very different from the students’ native language, and they had no previous experience of it. The level of intensity was of course much less.

I do wonder if the fact that the language being studied was Mandarin Chinese limits the generality of these findings. Because of the pictorial nature of the written language, Chinese has been shown to involve a wider network of regions than European languages.

Nevertheless, the findings add to the evidence that adult brains retain the capacity to reorganize themselves, and add to growing evidence that we should be paying more attention to white matter changes.

[3143] Schlegel AA, Rudelson JJ, Tse PU. White Matter Structure Changes as Adults Learn a Second Language. Journal of Cognitive Neuroscience [Internet]. 2012 ;24(8):1664 - 1670. Available from:

Bialystok, E., Craik, F. I. M., & Luk, G. (2012). Bilingualism: consequences for mind and brain. Trends in Cognitive Sciences, 16(4), 240–250. doi:10.1016/j.tics.2012.03.001

Luk, G. et al. (2011) Lifelong bilingualism maintains white matter integrity in older adults. J. Neurosci. 31, 16808–16813

My recent reports on brain training for older adults (see, e.g., Review of working memory training programs finds no broader benefit; Cognitive training shown to help healthy older adults; Video game training benefits cognition in some older adults) converge on the idea that cognitive training can indeed be beneficial for older adults’ cognition, but there’s little wider transfer beyond the skills being practiced. That in itself can be valuable, but it does reinforce the idea that the best cognitive training covers a number of different domains or skill-sets. A new study adds little to this evidence, but does perhaps emphasize the importance of persistence and regularity in training.

The study involved 59 older adults (average age 84), of whom 33 used a brain fitness program 5 days a week for 30 minutes a day for at least 8 weeks, while the other group of 26 were put on a waiting list for the program. After two months, both groups were given access to the program, and both were encouraged to use it as much or as little as they wanted. Cognitive testing occurred before the program started, at two months, and at six months.

The first group to use the program used the program on average for 80 sessions, compared to an average 44 sessions for the wait-list group.

The higher use group showed significantly higher cognitive scores (delayed memory test; Boston Naming test) at both two and six months, while the lower (and later) use group showed improvement at the end of the six month period, but not as much as the higher use group.

I’m afraid I don’t have any more details (some details of the training program would be nice) because it was a conference presentation, so I only have access to the press release and the abstract. Because we don’t know exactly what the training entailed, we don’t know the extent to which it practiced the same skills that were tested. But we may at least add it to the evidence that you can improve cognitive skills by regular training, and that the length/amount of training (and perhaps regularity, since the average number of sessions for the wait-list group implies an average engagement of some three times a week, while the high-use group seem to have maintained their five-times-a-week habit) matters.

Another interesting presentation at the conference was an investigation into mental stimulating activities and brain activity in older adults.

In this study, 151 older adults (average age 82) from the Rush Memory and Aging Project answered questions about present and past cognitive activities, before undergoing brain scans. The questions concerned how frequently they engaged in mentally stimulating activities (such as reading books, writing letters, visiting a library, playing games) and the availability of cognitive resources (such as books, dictionaries, encyclopedias) in their home, during their lifetime (specifically, at ages 6, 12, 18, 40, and now).

Higher levels of cognitive activity and cognitive resources were also associated with better cognitive performance. Moreover, after controlling for education and total brain size, it was found that frequent cognitive activity in late life was associated with greater functional connectivity between the posterior cingulate cortex and several other regions (right orbital and middle frontal gyrus, left inferior frontal gyrus, hippocampus, right cerebellum, left inferior parietal cortex). More cognitive resources throughout life was associated with greater functional connectivity between the posterior cingulate cortex and several other regions (left superior occipital gyrus, left precuneus, left cuneus, right anterior cingulate, right middle frontal gyrus, and left inferior frontal gyrus).

Previous research has implicated a decline in connectivity with the posterior cingulate cortex in mild cognitive impairment and Alzheimer’s disease.

Cognitive activity earlier in life was not associated with differences in connectivity.

The findings provide further support for the idea “Use it or lose it!”, and suggests that mental activity protects against cognitive decline by maintaining functional connectivity in important neural networks.

Miller, K.J. et al. 2012. Memory Improves With Extended Use of Computerized Brain Fitness Program Among Older Adults. Presented August 3 at the 2012 convention of the American Psychological Association.

Han, S.D. et al. 2012. Cognitive Activity and Resources Are Associated With PCC Functional Connectivity in Older Adults. Presented August 3 at the 2012 convention of the American Psychological Association.

The study involved 120 healthy older adults (60-79) from Shanghai, who were randomly assigned to one of four groups: one that participated in three sessions of tai chi every week for 40 weeks; another that instead had ‘social interaction’ sessions (‘lively discussions’); another in which participants engaged in walking around a track; and a non-intervention group included as a control. Brain scans were taken before and after the 40-week intervention, and cognitive testing took place at 20 weeks as well as these times.

Compared to those who received no intervention, both those who participated in tai chi, and those who participated in the social sessions, showed significant increases in brain volume and on some cognitive measures. However, the tai chi group showed improvement on more cognitive tests than the social group (on the Mattis Dementia Rating Scale, the Trailmaking Tests, delayed recognition on the Auditory Verbal Learning Test, and verbal fluency for animals vs verbal fluency and positive trends only on Trails A and the Auditory test).

Surprisingly, there were no such significant effects from the walking intervention, which involved 30 minutes of brisk walking around a 400m circular track, sandwiched by 10 minutes of warm-up and 10 minutes cool-down exercises. This took place in the same park as the tai chi sessions (which similarly included 20 minutes of warm-up exercises, 20 minutes of tai chi, and 10 minutes of cool-down exercises).

This finding is inconsistent with other research, but the answer seems to lie in individual differences — specifically, speed of walking. Faster walkers showed significantly better performance on the Stroop test, and on delayed recall and recognition on the Auditory Verbal Learning Test. It should be noted that, unlike some studies in which participants were encouraged to reach heart-rate targets, participants in this study were simply told to walk at their own speed. This finding, then, would seem to support the view that brisk walking is needed to reap good health and cognitive benefits (which shouldn’t put anyone off — anything is better than nothing! and speed is likely to come with practice, if that’s your aim).

It should also be noted that this population has generally high rates of walking. It is likely, then, that the additional walking in these sessions did not add a great deal to their existing behavior.

There is a caveat to the strongly positive effects of tai chi: this group showed lower cognitive performance at baseline. This was because the group randomly received more individuals with very low scores (8 compared with 5 in the other groups).

The study is, of course, quite a small one, and a larger study is required to confirm these results.

One final note: the relative differences in enjoyment were not explicitly investigated, but the researchers did note that the social group, who initially were given topics to discuss in their hour-long sessions, then decided to select and organize their own discussions, and have continued to do so for two years following the end of the study. It would have been nice if the researchers had re-tested participants at that point.

Mortimer, J.A. et al. 2012. Changes in Brain Volume and Cognition in a Randomized Trial of Exercise and Social Interaction in a Community-Based Sample of Non-Demented Chinese Elders. Journal of Alzheimer's Disease, 30 (4), 757-766.
Full text available at

I often talk about the importance of attitudes and beliefs for memory and cognition. A new honey bee study provides support for this in relation to the effects of aging on the brain, and suggests that this principle extends across the animal kingdom.

Previous research has shown that bees that stay in the nest and take care of the young remain mentally competent, but they don’t nurse for ever. When they’re older (after about 2-3 weeks), they become foragers, and foraging bees age very quickly — both physically and mentally. Obviously, you would think, bees ‘retire’ to foraging, and their old age is brief (they begin to show cognitive decline after just two weeks).

But it’s not as simple as that, because in artificial hives where worker bees are all the same age, nurse bees of the same age as foragers don’t show the same cognitive and sensory decline. Moreover, nurse bees have been found to maintain their cognitive abilities for more than 100 days, while foragers die within 18 days and show cognitive declines after 13-15 days (although their ability to assess sweetness remains intact).

The researchers accordingly asked a very interesting question: what happens if the foragers return to babysitting?

To achieve this, they removed all of the younger nurse bees from the nest, leaving only the queen and babies. When the older, foraging bees returned to the nest, activity slowed down for several days, and then they re-organized themselves: some of the old bees returned to foraging; others took on the babysitting and housekeeping duties (cleaning, building the comb, and tending to the queen). After 10 days, around half of these latter bees had significantly improved their ability to learn new things.

This cognitive improvement was also associated with a change in two specific proteins in their brains: one that has been associated with protection against oxidative stress and inflammation associated with Alzheimer disease and Huntington disease in humans (Prx6), and another dubbed a “chaperone” protein because it protects other proteins from being damaged when brain or other tissues are exposed to cell-level stress.

Precisely what it is about returning to the hive that produces this effect is a matter of speculation, but this finding does show that learning impairment in old bees can be reversed by changes in behavior, and this reversal is correlated with specific changes in brain protein.

Having said this, it shouldn’t be overlooked that only some of the worker bees showed this brain plasticity. This is not, apparently, due to differences in genotype, but may depend on the amount of foraging experience.

The findings add weight to the idea that social interventions can help our brains stay younger, and are consistent with growing evidence that, in humans, social engagement helps protect against dementia and age-related cognitive impairment.

The (probably) experience-dependent individual differences shown by the bees is perhaps mirrored in our idea of cognitive reserve, but with a twist. The concept of cognitive reserve emphasizes that accumulating a wealth of cognitive experience (whether through education or occupation or other activities) protects your brain from the damage that might occur with age. But perhaps (and I’m speculating now) we should also consider the other side of this: repeated engagement in routine or undemanding activities may have a deleterious effect, independent of and additional to the absence of more stimulating activities.

More findings from the long-running Mayo Clinic Study of Aging reveal that using a computer plus taking moderate exercise reduces your risk of mild cognitive impairment significantly more than you would expect from simply adding together these two beneficial activities.

The study involved 926 older adults (70-93), of whom 109 (12%) were diagnosed with MCI. Participants completed questionnaires on physical exercise and mental stimulation within the previous year. Computer use was targeted in this analysis because of its popularity as a cognitive activity, and because it was particularly associated with reduced odds of having MCI.

Among the cognitively healthy, only 20.1% neither exercised moderately nor used a computer, compared to 37.6% of those with MCI. On the other hand, 36% of the cognitively healthy both exercised and used a computer, compared to only 18.3% of those with MCI. There was little difference between the two groups as regards exercise but no computer use, or computer use but no exercise.

The analysis took into account calorie intake, as well as education, depression, and other health factors. Daily calorie intake was significantly higher in those with MCI compared to those without (respective group medians of 2100 calories vs 1802) — note that the median BMI was the same for the two groups.

Moderate physical exercise was defined as brisk walking, hiking, aerobics, strength training, golfing without a golf cart, swimming, doubles tennis, yoga, martial arts, using exercise machines and weightlifting. Light exercise included activities such as bowling, leisurely walking, stretching, slow dancing, and golfing with a cart. Mentally stimulating activities included reading, crafts, computer use, playing games, playing music, group and social and artistic activities and watching less television.

It should be noted that the assessment of computer activities was very basic. The researchers suggest that in future studies, both duration and frequency should be assessed. I would add type of activity, although that would be a little more difficult to assess.

Overall, the findings add yet more weight to the evidence for the value of physical exercise and mental stimulation in staving off cognitive impairment in old age, and add the twist that doing both is much better than doing either one alone.

We know that physical exercise greatly helps you prevent cognitive decline with aging. We know that mental stimulation also helps you prevent age-related cognitive decline. So it was only a matter of time before someone came up with a way of combining the two. A new study found that older adults improved executive function more by participating in virtual reality-enhanced exercise ("exergames") that combine physical exercise with computer-simulated environments and interactive videogame features, compared to the same exercise without the enhancements.

The Cybercycle Study involved 79 older adults (aged 58-99) from independent living facilities with indoor access to a stationary exercise bike. Of the 79, 63 participants completed the three-month study, meaning that they achieved at least 25 rides during the three months.

Unfortunately, randomization was not as good as it should have been — although the researchers planned to randomize on an individual basis, various technical problems led them to randomize on a site basis (there were eight sites), with the result that the cybercycle group and the control bike group were significantly different in age and education. Although the researchers took this into account in the analysis, that is not the same as having groups that match in these all-important variables. However, at least the variables went in opposite directions: while the cybercycle group was significantly younger (average 75.7 vs 81.6 years), it was significantly less educated (average 12.6 vs 14.8 years).

Perhaps also partly off-setting the age advantage, the cybercycle group was in poorer shape than the control group (higher BMI, glucose levels, lower physical activity level, etc), although these differences weren’t statistically significant. IQ was also lower for the cybercycle group, if not significantly so (but note the high averages for both groups: 117.6 vs 120.6). One of the three tests of executive function, Color Trails, also showed a marked group difference, but the large variability in scores meant that this difference was not statistically significant.

Although participants were screened for disorders such as Alzheimer’s and Parkinson’s, and functional disability, many of both groups were assessed as having MCI — 16 of the 38 in the cybercycle group and 14 of the 41 in the control bike group.

Participants were given cognitive tests at enrolment, one month later (before the intervention began), and after the intervention ended. The stationary bikes were identical for both groups, except the experimental bike was equipped with a virtual reality display. Cybercycle participants experienced 3D tours and raced against a "ghost rider," an avatar based on their last best ride.

The hypothesis was that cybercycling would particularly benefit executive function, and this was borne out. Executive function (measured by the Color Trails, Stroop test, and Digits Backward) improved significantly more in the cybercycle condition, and indeed was the only cognitive task to do so (other cognitive tests included verbal fluency, verbal memory, visuospatial skill, motor function). Indeed, the control group, despite getting the same amount of exercise, got worse at the Digits Backward test, and failed to show any improvement on the Stroop test.

Moreover, significantly fewer cybercyclists progressed to MCI compared to the control group (three vs nine).

There were no differences in exercise quantity or quality between the two groups — which does argue against the idea that cyber-enhanced physical activity would be more motivating. However, the cybercycling group did tend to comment on their enjoyment of the exercise. While the enjoyment may not have translated into increased activity in this situation, it may well do so in a longer, less directed intervention — i.e. real life.

It should also be remembered that the intervention was relatively short, and that other cognitive tasks might take longer to show improvement than the more sensitive executive function. This is supported by the fact that levels of the brain growth factor BDNF, assessed in 30 participants, showed a significantly greater increase of BDNF in cybercyclists.

I should also emphasize that the level of physical exercise really wasn't that great, but nevertheless the size of the cybercycle's effect on executive function was greater than usually produced by aerobic exercise (a medium effect rather than a small one).

The idea that activities that combine physical and mental exercise are of greater cognitive benefit than the sum of benefits from each type of exercise on its own is not inconsistent with previous research, and in keeping with evidence from animal studies that physical exercise and mental stimulation help the brain via different mechanisms. Moreover, I have an idea that enjoyment (in itself, not as a proxy for motivation) may be a factor in the cognitive benefits derived from activities, whether physical or mental. Mere speculation, derived from two quite separate areas of research: the idea of “flow” / “being in the zone”, and the idea that humor has physiological benefits.

Of course, as discussed, this study has a number of methodological issues that limit its findings, but hopefully it will be the beginning of an interesting line of research.  

Do retired people tend to perform more poorly on cognitive tests than working people because you’re more likely to retire if your mental skills are starting to decline, or because retirement dulls the brain?

For nearly 20 years the United States has surveyed more than 22,000 Americans over age 50 every two years, and administered memory tests. A similar survey has also been taking place in Europe. A comparison of the 2004 data for the U.S., England, and eleven European countries (Austria, Belgium, Denmark, France, Germany, Greece, Italy, The Netherlands, Spain, Sweden, and Switzerland) has now revealed differences in the level of cognitive performance among older adults between the countries (the 60-64 year age group was used as it represents the greatest retirement-age difference between nations).

These differences show some correlation with differences in the age of retirement. Moreover, the differences also correlate to differences in government policy in terms of pensions — supporting the view that it is retirement that is causing the mental decline, not the decline that brings about early retirement.

Memory was tested through a simple word recall task — recalling a list of 10 nouns immediately and 10 minutes later. People in the United States did best, with an average score of 11 out of a possible 20. Those in England were very close behind, and Denmark and Sweden were both around 10. Switzerland, Germany and the Netherlands, and Austria were all clustered between 9 and 9 ½; Belgium and Greece a little lower. France averaged 8; Italy 7; Spain (the lowest) just over 6.

Now when the average cognitive score is mapped against the percentage of retired for 60-64 year olds, the points for each country (with one exception) cluster around a line with a slope of -5, indicating that there is a systematic relationship between these two variables, and that on average being retired is associated with a lower memory score of about 5 points on a 20-point scale. This is a very large effect.

But the correlation is not (unsurprisingly) exact. Although the top scorers, U.S., England and Denmark, are among those nations who have lower retirement rates at this age, Switzerland has the same levels as the U.S., and Sweden has the fewest retired of all (around 40% compared to around 47% for the U.S. and Switzerland). Most interesting of all, why does Spain, which has around 74% retired, show such a low cognitive score, when five other countries have even higher rates of retirement (Austria has over 90% retired)?

There are of course many other differences between the countries. One obvious one to look at would be the degree to which older people who are not working for pay are involved in voluntary work. There’s also the question of the extent to which different countries might have different occupation profiles, assuming that some occupations are more mentally stimulating than others, and the degree to which retired people are engaged in other activities, such as hobbies and clubs.

The paper also raises an important point, namely, that retirement may be preceded by years of ‘winding-down’, during which workers become progressively more reluctant to keep up with changes in their field, and employers become increasingly reluctant to invest in their training.

[1932] Rohwedder S, Willis RJ. Mental Retirement. Journal of Economic Perspectives [Internet]. 2010 ;24(1):119 - 138. Available from:

A long-running study involving 1,157 healthy older adults (65+) who were scored on a 5-point scale according to how often they participated in mental activities such as listening to the radio, watching television, reading, playing games and going to a museum, has found that this score is correlated to the rate of cognitive decline in later years.

Some 5 ½ years after this initial evaluation, 395 (34%) were found to have mild cognitive impairment and 148 (13%) to have Alzheimer’s. Participants were then tested at 3-yearly intervals for the next 6 years. The rate of cognitive decline in those without cognitive impairment was reduced by 52% for each point on the cognitive activity scale, but for those with Alzheimer's disease, the average rate of decline per year increased by 42% for each point on the cognitive activity scale. Rate of decline was unrelated to earlier cognitive activity in those with MCI (presumably they were at the balance point).

This is not terribly surprising when you think of it, if you assume that the benefit of mental stimulation is to improve your brain function so that it can better cope with the damage happening to it. But eventually it reaches the point where it can no longer compensate for that damage because it is so overwhelming.

A review of brain imaging and occupation data from 588 patients diagnosed with frontotemporal dementia has found that among the dementias affecting those 65 years and younger, FTD is as common as Alzheimer's disease. The study also found that the side of the brain first attacked (unlike Alzheimer’s, FTD typically begins with tissue loss in one hemisphere) is influenced by the person’s occupation.

Using occupation scores that reflect the type of skills emphasized, they found that patients with professions rated highly for verbal skills, such as school principals, had greater tissue loss on the right side of the brain, whereas those rated low for verbal skills, such as flight engineers, had greater tissue loss on the left side of the brain. This effect was expressed most clearly in the temporal lobes of the brain. In other words, the side of the brain least used in the patient's professional life was apparently the first attacked.

These findings are in keeping with the theory of cognitive reserve, but may be due to some asymmetry in the brain that both inclines them to a particular occupational path and renders the relatively deficient hemisphere more vulnerable in later life.

Confirming previous research, a study involving 270 Alzheimer’s patients has found that larger head size was associated with better performance on memory and thinking tests, even when there was an equivalent degree of brain damage. The findings are consistent with the theory of cognitive reserve. They also point to the importance of brain development early in life, since the brain reaches 93% of its final size at age six, and while partly determined by genes, brain growth is also influenced by nutrition, infections, and brain injuries.

A study (“Midlife in the United States”) assessing 3,343 men and women aged 32-84 (mean age 56), of whom almost 40% had at least a 4-year college degree, has found evidence that frequent cognitive activity can counteract the detrimental effect of poor education on age-related cognitive decline. Although, as expected, those with higher education engaged in cognitive activities more often and did better on the memory tests, those with lower education who engaged in reading, writing, attending lectures, doing word games or puzzles once or week or more had memory scores similar to people with more education on tests of episodic memory (although this effect did not occur for executive functioning).

[651] Lachman ME, Agrigoroaei S, Murphy C, Tun PA. Frequent cognitive activity compensates for education differences in episodic memory. The American Journal of Geriatric Psychiatry: Official Journal of the American Association for Geriatric Psychiatry [Internet]. 2010 ;18(1):4 - 10. Available from:

Older news items (pre-2010) brought over from the old website

Factors helping you maintain cognitive function in old age

An 8-year study of over 2,500 seniors in their 70s, has found that 53% showed normal age-related decline, 16% showed major cognitive decline, and an encouraging 30% had no change or improved on the tests over the years. The most important factors in determining whether a person maintained their cognitive health was education and literacy: those with a ninth grade literacy level or higher were nearly five times as likely to stay sharp than those with lower literacy levels; those with at least a high school education were nearly three times as likely to stay sharp as those who have less education. Lifestyle factors were also significant: non-smokers were nearly twice as likely to stay sharp as smokers; those who exercised moderately to vigorously at least once a week were 30% more likely to maintain their cognitive function than those who do not exercise that often; people working or volunteering and people who report living with someone were 24% more likely to maintain cognitive function.

[909] Ayonayon HN, Harris TB, For the Health ABC Study, Yaffe K, Fiocco AJ, Lindquist K, Vittinghoff E, Simonsick EM, Newman AB, Satterfield S, et al. Predictors of maintaining cognitive function in older adults: The Health ABC Study. Neurology [Internet]. 2009 ;72(23):2029 - 2035. Available from:

Mental exercise helps maintain cognitive function during aging

A review of clinical trials which have examined the effect of cognitive exercise on longitudinal cognitive performance in healthy elderly individuals found 7 studies that met the criteria, and concluded that cognitive exercise training in healthy older individuals produced strong and long-lasting protective effects on cognitive performance, although it has yet to be shown to prevent incident dementia.

Valenzuela, M. & Sachdev, P. 2009. Can Cognitive Exercise Prevent the Onset of Dementia? Systematic Review of Randomized Clinical Trials
with Longitudinal Follow-up. American Journal of Geriatric Psychiatry, 17 (3), 179-187.

Brain exercises improve memory and processing speed

In the first study to link a commercially available software program to improvement on unaffiliated standard measures of memory and to better performance on everyday tasks, a study involving 487 healthy adults over the age of 65 has found that those who used the Brain Fitness Program for 40 hours over the course of eight weeks (an hour a day, five days a week) became twice as fast in processing, while those who spent the same amount of time watching videos on art, history and literature topics followed by quizzes showed no significant improvement. They also performed significantly better on memory and attention tests for which they did not train, and many also reported significant improvements in everyday cognitive activities such as remembering names or understanding conversations in noisy restaurants. The Brain Fitness Program consists of six auditory exercises designed to help the brain improve the speed and accuracy of processing.

Smith, G.E. et al. 2009. A Cognitive Training Program Based on Principles of Brain Plasticity: Results from the Improvement in Memory with Plasticity-based Adaptive Cognitive Training (IMPACT) Study.

Some activities associated with less memory loss

A study involving 1321 randomly selected people aged 70 to 89, of whom 197 had mild cognitive impairment, has found that reading books, playing games, participating in computer activities or doing craft activities such as pottery or quilting was associated with a 30 to 50% decrease in the risk of developing memory loss compared to people who did not do those activities. Also, those who watched television for less than seven hours a day were 50% less likely to develop memory loss than people who watched for more than that. Other activities in later age were not significantly associated with a reduced chance of having MCI. Only two activities during middle age (50-65) were significantly associated with a reduced chance of later memory loss: participation in social activities and reading magazines.

Geda, Y.E. et al. 2009. Cognitive Activities Are Associated with Decreased Risk of Mild Cognitive Impairment: The Mayo Clinic Population-Based Study of Aging. Presented April 28 at the American Academy of Neurology's 61st Annual Meeting in Seattle, April 25 to May 2, 2009.

No support for 'brain exercise' software for healthy elderly

A review of research on the impact of cognitive training on the healthy elderly (not those with mild cognitive impairment or Alzheimer's disease), has found no evidence that structured cognitive intervention programs affects the progression of dementia in the healthy elderly population. This is not to say that it doesn’t; the fault lies in the quality of the research. The researchers found only a very small number of studies that met their criteria. Those that did meet the criteria were mostly found to be limited in their methodologies or lacking in follow-up. They concluded that more random clinical trials in cognitive training need to be conducted with sufficient follow-up time that can actually measure changes in daily functioning.

Papp, K.V., Walsh, S.J. & Snyder, P.J. 2009. Immediate and delayed effects of cognitive interventions in healthy elderly: A review of current literature and future directions. Alzheimer's & Dementia, 5 (1), 50-60.

Education may not affect how fast you will lose your memory

A study involving some 6,500 older Chicago residents being interviewed 3-yearly for up to 14 years (average 6.5 years), has found that while at the beginning of the study, those with more education had better memory and thinking skills than those with less education, education was not related to how rapidly these skills declined during the course of the study. The result suggests that the benefit of more education in reducing dementia risk results simply from the difference in level of cognitive function.

Wilson, R.S., Hebert, L.E., Scherr, P.A., Barnes, L.L., de Leon, C.F.M. & Evans, D.A. 2009. Educational attainment and cognitive decline in old age. Neurology, 72, 460-465.

Active social life may delay memory loss among older adults

Data gathered from 1998 to 2004 from the very large U.S. Health and Retirement Study has supported previous research suggesting that social activity is associated with slower cognitive decline. Indeed, memory decline among those with the highest social integration was less than half the rate among the least integrated. Social integration was assessed by marital status, volunteer activity, and frequency of contact with children, parents, and neighbors. The findings were independent of sociodemographic factors (such as age, gender, and race) and health status in 1998. The researchers found that the protective effect of social integration was largest among individuals with fewer than 12 years of education. There was no evidence that a poor or declining memory caused social withdrawal.

Ertel, K.A., Glymour, M.M. & Berkman, L.F. 2008. Effects of Social Integration on Preserving Memory Function in a Nationally Representative U.S. Elderly Population. American Journal of Public Health, 98 (7), 1215-1220.

Incidentally, another study that appeared in the same issue found that larger social networks were associated with a lower risk of dementia in women aged 78 and older. The study examined 2249 members of a health maintenance organization who were free of dementia at the start of the study. 268 (12%) of these were identified as having dementia four years later.

Crooks, V.C. et al. 2008. Social Network, Cognitive Function, and Dementia Incidence Among Elderly Women. American Journal of Public Health, 98, 1221-1227.

Older adults with more schooling spend fewer years with cognitive loss

A seven-year study involving over 7,000 people 70 years and older has found that a 70-year old person with at least 12 years of education can expect to live 14.1 more years without cognitive impairment, which is two-and-a-half years more than 70-year olds with fewer than 12 years of education. They can then expect to spend 1 year with impairment, which is about 7 months less than a person with fewer years of education. The impairment is also likely to be more severe for the more educated, and associated with worse health. This is consistent with the idea of cognitive reserve — that education provides a “buffer” that enables people to continue functioning well despite physical damage in the brain. However, when the damage finally can no longer be compensated for, the effects will be greater. But it shouldn’t be assumed that it is all downhill from there — even the severely impaired may recover, depending on the cause. Overall, about 11% of the mentally impaired recover, presumably because the decline is caused by a treatable condition.

Lièvre, A., Alley, D. & Crimmins, E. 2008. Educational Differentials in Life Expectancy With Cognitive Impairment Among the Elderly in the United States. Journal of Aging and Health, 20, 456-477.

10 minutes of talking has a mental payoff

A study of 3,610 people aged 24—96 examined mental functioning and social interaction, and found that, across all ages, cognitive functioning was better the The higher the level of participants' social interaction. Participants' level of social interactions was assessed by asking how often each week they talked on the phone with friends, neighbors and relatives, and how often they got together. Researchers controlled for age, education, race/ethnicity, gender, marital status and income, physical health and depression. In a second experiment involving college students, short-term social interaction lasting for just 10 minutes boosted participants' intellectual performance as much as engaging in so-called 'intellectual' activities for the same amount of time.

Ybarra, O., Burnstein, E., Winkielman, P., Keller, M. C., Manis, M., Chan, E., & Rodriguez, J. (2008). Mental Exercising Through Simple Socializing: Social Interaction Promotes General Cognitive Functioning. Personality and Social Psychology Bulletin, 34(2), 248 –259. doi:10.1177/0146167207310454

Age differences in cognitive benefits of exercise and mental stimulation

A mouse study has found that while physical exercise (a running wheel) and mental stimulation (toys), singly and together, improved memory in old mice, exercise alone or exercise and stimulation improved memory in middle-aged mice but not stimulation alone, and only exercise alone benefited young mice. The results suggest that as we get old and maybe less able to exercise, cognitive stimulation can help to compensate, but exercise is central to memory reinforcement at all ages.

Harburger, L.L., Nzerem, C.K. & Frick, K.M. 2007. Single Enrichment Variables Differentially Reduce Age-Related Memory Decline in Female Mice. Behavioral Neuroscience, 121 (4), 679-688.

Alzheimer's pathology related to episodic memory loss in those without dementia

A study of 134 participants from the Religious Orders Study or the Memory and Aging Project has found that, although they didn't have cognitive impairment at the time of their death, more than a third of the participants (50) met criteria for a pathologic diagnosis of Alzheimer's disease. This group also scored significantly lower on tests for episodic memory, such as recalling stories and word lists. The results provide further support for the idea that a ‘cognitive reserve’ can allow people to tolerate a significant amount of Alzheimer's pathology without manifesting obvious dementia. It also raises the question whether we should accept any minor episodic memory loss in older adults as 'normal'.

Bennett, D.A., Schneider, J.A., Arvanitakis, Z., Kelly, J.F., Aggarwal, N.T., Shah, R.C. & Wilson, R.S. 2006. Neuropathology of older persons without cognitive impairment from two community-based studies. Neurology, 66, 1837-1844.

Simple Lifestyle Changes May Improve Cognitive Function

A study involving 17 people (35–69 years) with mild self-reported memory complaints but normal baseline memory performance scores, has found that 2 weeks on a program combining a brain healthy diet plan (5 small meals a day; diet rich in omega-3 fats, antioxidants and low-glycemic carbohydrates like whole grains), relaxation exercises, cardiovascular conditioning (daily walks), and mental exercise (such as crosswords and brain teasers) resulted in participants' brain metabolism decreasing 5% in working memory regions (left dorsolateral prefrontal cortex), suggesting an increased efficiency. Compared to the control group, participants also performed better in verbal fluency.

Small, G.W. et al. 2006. Effects of a 14-Day Healthy Longevity Lifestyle Program on Cognition and Brain Function. American Journal of Geriatric Psychiatry, 14, 538-545.

Risk of mild cognitive impairment increases with less education

A study of 3,957 people from the general population of Olmsted County, Minnesota is currently in train to find how many of those who did not have dementia might have mild cognitive impairment. A report on the findings so far suggests 9% of those aged 70 to 79 and nearly 18% of those 80 to 89 have MCI. Prevalence varied not only with age but also years of education: 25% in those with up to eight years of education, 14% in those with nine to 12 years, 9% in those with 13 to 16 years, and 8.5% in those with greater than 16 years.

Findings from this study were presented April 4 at the American Academy of Neurology meeting in San Diego.

Lifestyle changes improve seniors’ memory surprisingly quickly

A small 14-day study found that those following a memory improvement plan that included memory training, a healthy diet, physical exercise, and stress reduction, showed a 5% decrease in brain metabolism in the dorsal lateral prefrontal region of the brain (involved in working memory) suggesting they were using their brain more efficiently. This change in activity was reflected in better performance on a cognitive measure controlled by this brain region, and participants reported that they felt their memory had improved. The memory training involved doing brainteasers, crossword puzzles and memory exercises. Diet involved eating 5 small meals daily (to prevent fluctuations in blood glucose levels) that were rich in omega-3 fats, low-glycemic index carbohydrates (e.g., whole grains) and antioxidants. Physical exercise involved brisk walking and stretching, and stress reduction involved stretching and relaxation exercises.

The study was presented at the American College of Neuropsychopharmacology's Annual Meeting on December 11-15, in Hawaii.

How higher education protects older adults from cognitive decline

Research has indicated that higher education helps protect older adults from cognitive decline. Now an imaging study helps us understand how. The study compared adults from two age groups: 18-30, and over 65. Years of education ranged from 11 to 20 years for the younger group, and 8 to 21 for the older. Participants carried out several memory tasks while their brain was scanned. In young adults performing the memory tasks, more education was associated with less use of the frontal lobes and more use of the temporal lobes. For the older adults doing the same tasks, more education was associated with less use of the temporal lobes and more use of the frontal lobes. Previous research has indicated frontal activity is greater in old adults, compared to young; the new study suggests that this effect is related to the educational level in the older participants. The higher the education, the more likely the older adult is to recruit frontal regions, resulting in a better memory performance.

Springer, M.V., McIntosh, A.R., Winocur, G. & Grady, C.L. 2005. The Relation Between Brain Activity During Memory Tasks and Years of Education in Young and Older adults. Neuropsychology and Aging, 19 (2)

Diet, exercise, stimulating environment helps old dogs learn

A new study of beagles provides more evidence that diet and mental stimulation are important in reducing or preventing age-related cognitive decline. The study, involving 48 older beagles (aged 7 to 11), compared four combinations of behavioral enrichment (regular exercise and lots of mental stimulation) and supplementation of diet with antioxidants had on a beagle's ability to learn: regular diet and regular experience; regular diet and enriched experience; regular experience and an enriched diet; and enriched diet and an enriched experience. The study followed the beagles over two years. Those in the groups with either an enriched diet or enriched environment did better than those without either, but those who had both the enriched diet and an enriched environment did noticeably better than all the rest.

Milgram, N.W., Head, E., Zicker, S.C., Ikeda-Douglas, C.J., Murphey, H., Muggenburg, B., Siwak, C., Tapp, D., & Cotman, C.W. 2005. Learning ability in aged beagle dogs is preserved by behavioral enrichment and dietary fortification: a two-year longitudinal study. Neurobiology of Aging, 26, 77-90.

Being fluent in two languages may help keep the brain sharper for longer

A study of 104 people aged between 30 and 88 has found that those who were fluent in two languages rather than just one were sharper mentally. Those fluent in two languages responded faster on tasks assumed to place demands on working memory, compared to those who were fluent in just English, at all age groups. This is consistent with the theory that constant management of 2 competing languages enhances executive functions. Bilingual volunteers were also much less likely to suffer from the mental decline associated with old age. The finding is consistent with other research suggesting that mental activity helps in protecting older adults from mental decline. The participants were all middle class, and educated to degree level. Half of the volunteers came from Canada and spoke only English. The other half came from India and were fluent in both English and Tamil.

Bialystok, E., Craik, F.I.M., Klein, R. & Viswanathan, M. 2004. Bilingualism, Aging, and Cognitive Control: Evidence From the Simon Task. Psychology and Aging, 19 (2), 290–303.

Low self-esteem 'shrinks brain'

A British study questioned some 5,350 civil servants aged between 35 and 55 about their participation in 13 leisure activities, ranging from DIY and housework to cultural visits and evening classes. They were then given tests in verbal memory, mathematical reasoning, vocabulary and verbal fluency. Independent of socio-economic position, the highest level of cognitive ability was associated with regular cultural visits to theatres, art galleries and stately homes. This was closely followed by reading and listening to music, then by involvement in clubs and voluntary organisations, and participation in courses and evening classes. The association was stronger among men. While the researchers suggested that seeking mental stimulation may have a beneficial effect on cognition in middle age, and the research was popularly reported as indicating that “going to the pub is good for the brain” (going to the pub was indeed associated with a slightly higher cognitive ability, but less so that the afore-mentioned), it must be remembered that correlation does not imply causation.

Singh-Manoux, A., Richards, M. & Marmot, M. 2003. Leisure activities and cognitive function in middle age: evidence from the Whitehall II study. Journal of Epidemiology and Community Health, 57, 907-913.

More support for importance of stimulation to protect against cognitive decline

A 15-year study of 92 seniors found that those with a low sense of self worth were more likely to suffer from memory loss as they got older. Moreover, the brains of those with low self-worth were up to a fifth smaller than those who felt good about themselves. It is speculated that those who are anxious and think negatively may set themselves up for memory loss by not bothering to engage themselves in activities that would stimulate and enrich their brains.

The study was presented at a conference at the Royal Society in London.

Regular participation in cognitive activities reduces Alzheimer's risk

6,158 persons aged 65 years and older from a biracial community in Chicago self-rated current frequency of participation in seven cognitive activities (e.g., reading a newspaper) and nine physical activities (e.g., walking for exercise). Four years later, 842 of those judged dementia-free were given a detailed clinical evaluation. 139 of these met criteria for Alzheimer's on clinical evaluation. When adjusted for age, education, sex, race, and possession of the gene allele associated with Alzheimer's, a one-point increase in cognitive activity score was associated with a 64% reduction in risk of Alzheimer's. Weekly hours of physical activity had no effect. Education and occupation were both associated with Alzheimer's risk, but these effects were substantially reduced when cognitive activity was taken into account.

Wilson, R.S., Bennett, D.A., Bienias, J.L., Aggarwal, N.T., de Leon, M.C.F., Morris, M.C., Schneider, J.A. & Evans, D.A. 2002. Cognitive activity and incident AD in a population-based sample of older persons. Neurology, 59, 1910-1914.

Compensating strategies for aging memories

PET scans of the prefrontal cortex reveal that older adults who perform better on a simple memory task display more activity on both sides of the brain, compared to both older adults who do less well, and younger adults. Although this seems counter-intuitive – the older adults who perform less well show activity patterns more similar to that of younger adults, this supports recent theory that the brain may change tactics as it ages, and that older people whose brain is more flexible can compensate for some aspects of memory decline. Whether this flexibility is neurological, or something that can be taught, is still unknown.

Cabeza, R., Anderson, N.D., Locantore, J.K. & McIntosh, A.R. 2002. Aging Gracefully: Compensatory Brain Activity in High-Performing Older Adults. NeuroImage, 17(3), 1394-1402

Talking may help seniors guard against memory decline

Earlier research has indicated cognitively stimulating activities (such as doing crosswords, playing scrabble, bridge, etc.) may help protect against cognitive decline (and perhaps even Alzheimers). Now a new report (not yet published) from the Institute for Social Research at the University of Michigan supports and extends this research by suggesting that simply talking helps keep your mind sharp at all ages. The lead researcher also speculates that, by encouraging children to develop their social skills, parents and teachers could also be helping them to improve their intellectual skills. And in the workplace, instead of encouraging employees to keep their noses to computer monitors and complete their tasks, effective supervisors might encourage them to take plenty of time out to socialize.

Mentally stimulating activities reduces cognitive decline

A study of 700 seniors over several years found that more frequent participation in cognitively stimulating activities, such as reading books, newspapers or magazines, engaging in crosswords or card games, was significantly associated with a reduced risk of Alzheimer’s disease (AD). General cognitive decline was also less among people who did more cognitively stimulating activities, in particular, in working memory, perceptual speed, and episodic memory. It is not yet known whether engaging in such activities helps prevent cognitive decline, or whether those who develop cognitive impairment are less likely to engage in cognitively stimulating activities.

Wilson RS, Mendes de Leon CF, Barnes LL, & et al. (2002). Participation in cognitively stimulating activities and risk of incident alzheimer disease. JAMA, 287(6), 742–748. doi:10.1001/jama.287.6.742

Leisure activity decreases risk of Alzheimer's disease

1,772 people age 65 or older participated in a 7-year study that investigated the effect of leisure activities on risk of dementia. It was found that, even when controlling for factors like ethnic group, education and occupation, those with high leisure activity had 38% less risk of developing dementia. There also appeared to be a cumulative effect, with an additional 8% risk reduction associated with each leisure activity engaged. Activities of all kinds were shown to be beneficial, but intellectual activities were associated with the highest risk reduction.

Scarmeas, N., Levy, G., Tang, M-X., Manly, J. & Stern, Y. 2001. Influence of leisure activity on the incidence of Alzheimer’s Disease. Neurology, 57, 2236-2242.

Dealing with memory failures in which you feel the information you want is "on the tip of my tongue"

Memory failures in which you feel the information you want is "on the tip of my tongue" appear to occur because the memory trails to those items have become faint, either because the items haven't been used regularly or because of age. Similar sounding items can help recall. To keep your memory trails strong, you need to use them - by reading, doing crosswords, anything that uses language and keeps you meeting new words.

James, L. E., & Burke, D. M. (2000). Phonological Priming Effects on Word Retrieval and Tip-of-the-Tongue Experiences in Young and Older Adults,. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26(6), 1378–1391.