Cognitive reserve: why mentally demanding games matter after 60
Cognitive reserve is the brain’s ability to keep functioning well despite damage linked to age or illness. It is built throughout life through education, work and stimulating leisure activities. It is the hypothesis most often put forward to explain why people who play games or read a lot decline, on average, a little later.
Cognitive reserve: the brain’s ability to compensate for damage linked to age or illness thanks to more efficient networks or substitute strategies, built through education, occupational activity and stimulating leisure activities. The concept was formalised by the neuropsychologist Yaakov Stern, of Columbia University in New York.
Cognitive reserve: where the idea comes from
Doctors have long made a puzzling observation: with comparable brain damage, some people show symptoms of dementia and others do not. Yaakov Stern proposed distinguishing two notions:
- brain reserve, of a “hardware” kind: a larger brain, with more neurons and connections, withstands more loss before failing;
- cognitive reserve, of a “software” kind: a trained brain uses its networks more efficiently and knows how to turn to other strategies when the first ones falter.
This reserve cannot be seen directly. It is estimated from indicators: years of education, complexity of occupation, richness of leisure activities, vocabulary. People with a lot of reserve are not spared by the illness; they mask its effects for longer, and sometimes decline faster once symptoms appear, when the compensation is exhausted.
The Nun Study: lesions without symptoms
The most famous illustration comes from the Nun Study, launched in the 1980s by the epidemiologist David Snowdon among 678 nuns of the School Sisters of Notre Dame congregation in the United States, aged 75 to 102. The sisters agreed to regular tests and to donate their brains after death.
Two lessons have endured. First, some nuns showed lesions typical of Alzheimer’s disease at autopsy although they had shown no impairment during their lifetime. Second, the richness of expression in the autobiographies the sisters wrote on entering the order, decades earlier, was linked to the risk of developing the disease later. The brain can therefore sustain damage without the mind collapsing, and abilities built early seem to matter.
The Religious Orders Study, another cohort of American members of religious orders, then directly measured cognitive activities in everyday life.
Wilson et al., 2002 · JAMA
Participation in cognitively stimulating activities and risk of incident Alzheimer disease
- Who
- 801 elderly Catholic nuns, priests and brothers (Religious Orders Study, United States)
- Type
- Observational cohort, mean follow-up 4.5 years · level of evidence: Moderate (association)
- Result
- 111 cases of Alzheimer’s disease. Each additional point of cognitive activity (reading, games, etc.) is associated with a risk reduced by about a third (HR 0.67); a very active person (90th percentile) has a 47% lower risk than a person with little activity (10th percentile).
- What the study does not say
- A very particular population (members of religious orders, high level of education); the authors point out that causation is not established.
Which activities strengthen cognitive reserve?
The factors associated with a higher reserve are known, even though their individual effect remains hard to isolate.
| Factor | What is observed | Strength |
|---|---|---|
| Level of education | A low level of education is one of the 14 risk factors identified by the Lancet Commission in 2024 | solid |
| Complex occupation | Jobs that demand reasoning and dealing with people are associated with a lower risk | promising |
| Intellectual pastimes (reading, games, chess) | Associated with slower decline in several cohorts (Wilson 2002, Dartigues 2013, Wu 2023) | promising |
| Social life | Social isolation is a risk factor recognised by the Lancet | solid |
| Physical activity | Physical inactivity is a recognised risk factor | solid |
| Bilingualism, music | Results vary from study to study | fragile |
Mentally demanding games have the advantage of combining several of these ingredients: intellectual effort, continuous learning, and often meeting other people. Chess adds an almost infinite depth: you can improve at 70 just as at 10. Our comparison of games to train your brain details what each game calls on, and Le Palais des Échecs offers a selection of board games that exercise the intellect.
One point deserves emphasis: novelty and effort probably matter more than the activity itself. Doing the same easy grid every day demands little; learning a new opening, analysing your games or facing varied opponents forces you to learn.
Cognitive stimulation: definition and exercises
Cognitive stimulation: a set of structured activities that call on memory, attention, language and reasoning. The term refers both to a leisure approach for everyone and, in medicine, to a programme evaluated in people with mild to moderate dementia.
How can you stimulate your cognitive functions day to day? A few simple exercises, needing no special equipment:
- learn something genuinely new (a language, an instrument, a chess variant);
- solve one chess problem a day, writing down your solution before checking it;
- recount a book, a film or a game to someone, which exercises memory and language;
- alternate games: a word game, a logic game, a strategy game;
- play with others rather than alone, for the social element and the variety of situations.
For people already affected by the illness, see the page cognitive stimulation games for Alzheimer’s and our guide to running a chess workshop in a care home.
The limits of the concept
What cognitive reserve does not explain
- It cannot be measured directly: it is inferred from indirect indicators such as years of education.
- It delays the expression of symptoms; it does not prevent the lesions of the illness.
- We do not know what “dose” of activity would be useful, nor whether an activity begun late counts as much as a lifelong habit.
- In cohorts, the individual effect of leisure activities is hard to separate from that of education and health (see the adjustment in the PAQUID study, Dartigues et al., 2013).
How learning physically changes the brain is another question, dealt with on the page about the chess player’s brain and neuroplasticity.
Frequently asked questions
What is cognitive reserve?
It is the brain’s ability to compensate for damage linked to age or illness, thanks to more efficient networks or to other strategies. It is built through education, work and stimulating leisure activities, according to the concept formalised by Yaakov Stern.
How can you improve your cognitive reserve?
By staying intellectually, physically and socially active throughout life: learning new things, reading, playing mentally demanding games, keeping in touch with people, moving every day. Studies associate these habits with a later decline, without being able to guarantee the effect.
Which activities strengthen cognitive reserve?
Education, a stimulating job, reading, mentally demanding games such as chess, bridge or crosswords, social life and physical activity. What seems to matter is effort and novelty, more than the precise choice of activity.
What is cognitive development?
It is the development of thinking abilities (perception, memory, language, reasoning) from birth to adulthood. The term mainly concerns childhood; in older adults, we speak rather of maintaining cognitive function and of cognitive reserve.