This page is a summary of published research, not medical advice, and it is not a firsthand account of anything. Muse has never been studied and no claim is made for it; the work below concerns cognitive activity in general. Every study named is linked to the journal or agency that published it, so you can check any number here yourself. Anyone worried about their memory should talk to a doctor rather than to a puzzle game.
Two million people: cognitive activity and dementia risk
The largest look at this question was published in Neurology in 2022. Researchers pooled 38 longitudinal studies covering 2,154,818 participants and asked what leisure activity predicted about dementia later on.
People taking part in cognitive leisure activities had a 23% lower incidence of all–cause dementia. For Alzheimer’s disease specifically the gap was larger: a 34% lower incidence. (Su et al., Neurology, 2022)
The activities counted across the underlying studies were ordinary ones — reading, writing, using a computer, playing cards, checkers, crosswords and other puzzles and games.
This is an association and not proof of cause and effect. People who do a lot of puzzles differ from people who do not in education, health, income and a dozen other ways, and any of those could be doing the work. What makes the result hard to wave off is its size and its consistency across studies designed independently of one another.
An earlier review found much the same thing
A separate systematic review and meta-analysis in International Psychogeriatrics examined 19 studies of cognitively stimulating leisure. Four of its five analyses found statistically significant relationships between more cognitive activity and less cognitive impairment or dementia, with risk reductions running from roughly 22% to 42% depending on the measure the underlying studies used. (Yates et al., International Psychogeriatrics, 2016)
The same review found associations with better memory, faster information processing, better executive function, and slower decline in both overall cognition and executive function.
Games in particular have been studied
Mayo Clinic researchers followed 1,929 cognitively normal adults aged 70 and over for about four years, looking at playing games, computer use, craft activities and social activities.
Taking part was associated with significantly lower risk of developing mild cognitive impairment — decline greater than normal aging accounts for, but short of dementia. Some people with MCI later develop dementia and some never do, which is what makes it worth measuring on its own. (Krell-Roesch et al., JAMA Neurology, 2017)
The authors concluded that mentally stimulating activities may be associated with lower risk of MCI even when taken up late in life.
What about people who already have impairment?
A randomised trial funded by the National Institute on Aging put 107 adults who already had mild cognitive impairment into one of two arms: computerised crossword training, or computerised cognitive games. Both trained intensively for 12 weeks, then took booster sessions across a 78–week study.
The crossword group did better on the study’s primary cognitive measure. Brain imaging pointed the same way: declines in hippocampal volume and cortical thickness were greater in the games group than in the crossword group. (Devanand et al., NEJM Evidence, 2022)
It was a small trial and it is not proof that crosswords slow Alzheimer’s disease. What it shows is that puzzle–based activity is being tested as a serious intervention in people who are already impaired, and that not every screen full of puzzles behaves the same way.
Can training the brain produce lasting benefit?
The important study here is ACTIVE — Advanced Cognitive Training for Independent and Vital Elderly — a large randomised trial that began with thousands of adults aged 65 and over and tested three kinds of training:
- Memory training — strategies for holding on to what you have learned.
- Reasoning training — recognising and solving patterns and problems.
- Speed–of–processing training — identifying and processing visual information at increasing speed.
The National Institute on Aging reports that the reasoning and speed–of–processing benefits were still detectable ten years after the original training. (NIA, Cognitive Health and Older Adults)
The peer–reviewed analysis of dementia in those same participants found that people assigned to speed–of–processing training were about 29% less likely to develop dementia across those ten years than the control group, with risk falling roughly 8% for each training session completed. An earlier conference report of the same analysis put the figure at 33%; the published number is the one to quote. (Edwards et al., Alzheimer’s & Dementia: TRCI, 2017)
Researchers specifically warn against reading that as a promise about brain games in general. What ACTIVE established is narrower and still surprising: some structured cognitive exercise leaves a mark that is still there a decade later.
Why might any of this work? Cognitive reserve
The usual explanation is cognitive reserve: the brain’s capacity to keep functioning despite aging, disease or injury. Two people can show similar physical changes in the brain and very different degrees of impairment, and researchers think education, demanding work, lifelong learning and mentally stimulating activity all feed that difference.
A hard logic puzzle asks for several things at once:
- Reasoning, and planning several steps ahead
- Working memory, to hold intermediate goals
- Attention and pattern recognition
- Spatial processing
- Predicting the consequences of an action
- Noticing a mistake, and changing strategy after one
Recalling a fact uses one of those. A puzzle keeps all of them going at once, and keeps deciding what to do next — which is why puzzles interest people studying healthy cognitive aging in the first place.
The WHO now names puzzles and games
In 2026 the World Health Organization published the second edition of its Risk Reduction of Cognitive Decline and Dementia guidelines, and describes cognitively stimulating activities as including everyday ones: reading, puzzles and games. (WHO guidelines, second edition, 2026)
Its recommendation is that cognitive training may be offered to older adults with normal cognition or mild cognitive impairment to reduce the risk of cognitive decline or dementia, and that engagement in cognitive stimulation may be encouraged.
Both are conditional recommendations. The WHO rates the certainty of the underlying evidence as low for cognitive training and very low for cognitive stimulation. That is the honest shape of it: strong enough to be written into international guidance, nowhere near strong enough to say puzzles prevent Alzheimer’s disease.
Not every “brain game” is equal
Calling a product a brain game does not make it protective. The US National Institute on Aging cautions that there is not enough evidence to conclude that commercially available brain–training applications have the same impact on thinking as the training used in ACTIVE, and advises being wary of claims that a particular game will improve your memory. (NIA, Preventing Alzheimer’s Disease: What Do We Know?)
Results are mixed. Some studies find benefits; others find small ones, or improvement confined to the exact skill being drilled. A systematic review and meta-analysis of randomised controlled trials in older adults with cognitive impairment found no superior effect of brain gaming over other interventions on global cognitive function. (Journal of the American Medical Directors Association, 2021)
So: mental activity looks beneficial, and which activities give the most durable protection is still an open scientific question.
What makes a logic puzzle demanding
Consider a puzzle where you move objects through a constrained space. Getting through it means reading the current arrangement, finding the legal moves, predicting what each one does, holding the sub–goals in mind, spotting the arrangements that would make the puzzle unwinnable, planning ahead, catching your own mistakes, backing out of a failed plan and building a new one — then remembering the shape of what worked, for next time.
That is a great deal more than passive entertainment asks for. And when the puzzles keep getting less familiar, you have to keep adapting instead of repeating a memorised answer. The WHO makes that point too: cognitive stimulation may matter most when the activity is new and challenging.
Where Muse comes into it
Muse was built around exactly this kind of problem. The goal states in a sentence — get every block onto a slot — and the difficulty is that a block can be pushed and never pulled, so a harmless–looking move can make a board much harder, or quietly impossible. You are never only deciding where a block should end up. You are deciding what this move does to the moves you will still have five moves from now.
Planning, spatial reasoning, pattern recognition, working memory, constant problem solving. It is the same list as above, which is not a coincidence — it is what the puzzle is made of.
Muse is a puzzle game and not a medical treatment. We make no claim that playing it prevents or treats Alzheimer’s disease, dementia or anything else. It belongs to the broad category of challenging, cognitively stimulating activity that researchers think may be worth something — and that is the whole of the claim.
The rules, the pieces and how a board is actually solved →
One piece of a much bigger picture
Brain health does not rest on one activity. Dementia–prevention research points at a whole way of living:
- Regular physical activity
- Blood pressure and cardiovascular health
- Not smoking
- Keeping up social connections
- Treating hearing loss
- Eating well
- Continuing to learn, and staying mentally active
A puzzle is no substitute for a walk, a conversation, or a doctor. It goes alongside them.
So — can puzzles prevent dementia?
Science is not ready to say that. What it can say is more interesting than the usual line about exercising your brain.
Large observational studies link cognitively stimulating leisure to lower rates of dementia and Alzheimer’s disease. Randomised trials show that some structured cognitive training produces benefits lasting years. Studies in people who already have mild cognitive impairment have measured gains from certain puzzle activities. And the World Health Organization now counts puzzles and games among the cognitively stimulating activities that may be encouraged as part of reducing dementia risk.
That is reason enough to keep giving your mind something hard to do — not because today’s puzzle buys you anything tomorrow, but because a growing body of research suggests that a brain kept learning, reasoning and solving is part of aging well.
And there is one advantage nobody has to prove: puzzles are fun.
References
- World Health Organization. Risk reduction of cognitive decline and dementia: WHO guidelines, second edition. 2026.
- Su S, Shi L, Zheng Y, et al. Leisure Activities and the Risk of Dementia: A Systematic Review and Meta-analysis. Neurology. 2022;99(15):e1651–e1663.
- Yates LA, Ziser S, Spector A, Orrell M. Cognitive leisure activities and future risk of cognitive impairment and dementia: systematic review and meta-analysis. International Psychogeriatrics. 2016;28(11):1791–1806.
- Krell-Roesch J, Vemuri P, Pink A, et al. Association Between Mentally Stimulating Activities in Late Life and the Outcome of Incident Mild Cognitive Impairment, With an Analysis of the APOE ε4 Genotype. JAMA Neurology. 2017;74(3):332–338.
- Devanand DP, Goldberg TE, Qian M, et al. Computerized Games versus Crosswords Training in Mild Cognitive Impairment. NEJM Evidence. 2022;1(12).
- Edwards JD, Xu H, Clark DO, et al. Speed of processing training results in lower risk of dementia. Alzheimer’s & Dementia: Translational Research & Clinical Interventions. 2017;3(4):603–611.
- Nguyen L, Murphy K, Andrews G. Effectiveness of Brain Gaming in Older Adults With Cognitive Impairments: A Systematic Review and Meta-Analysis. Journal of the American Medical Directors Association. 2021.
- National Institute on Aging. Preventing Alzheimer’s Disease: What Do We Know? National Institutes of Health.
- National Institute on Aging. Cognitive Health and Older Adults. National Institutes of Health.
Important note
Muse is an entertainment product. It is not intended to diagnose, treat, cure or prevent Alzheimer’s disease, dementia, mild cognitive impairment or any other medical condition. The research described above concerns broad categories of cognitive activity and cognitive training, and must not be read as showing a specific medical benefit from playing Muse.