Playing a game or completing in a puzzle is a great way to pass a rainy day or a long flight - but did you know the leisurely pastime could also benefit your health?
A new study suggests that playing games or doing puzzles may help stave off Alzheimer's disease.
The research, which was presented to the Alzheimer's Association International Conference in Copenhagen, found that these kinds of brain-stimulating activities could help to preserve vulnerable brain structures and cognitive functions.
People who spend more time playing mentally-stimulating games are also more likely to perform better in learning, memory and information processing tests, researchers said.
But charity Alzheimer's Research UK said that while the study contributes to the "use it or lose it" debate, it does not confirm whether or not playing such games prevents the condition.
The researchers, from Wisconsin Alzheimer's Institute and the Wisconsin Alzheimer's Disease Research Center in the US, examined 329 people with an average age of 60 who were healthy but deemed to be at a higher risk of Alzheimer's disease due to their genetic background or family history.
They performed a series of tests on them including brain scans and a number of cognitive assessments.
Meanwhile the participants were asked how often they took part in activities like reading books, going to museums and playing card games or doing puzzles.
The researchers found people who reported playing games such as cards, draughts, crosswords or other puzzles, were more likely to have a greater brain volume in several regions involved in Alzheimer's disease and higher scores on cognitive tests.
They concluded that for some individuals participating in such games could help prevent Alzheimer's disease.
Commenting on the study Dr Laura Phipps, science communications manager at Alzheimer's Research UK, said: "Observational studies like this are not able to pinpoint cause and effect, but they can be useful for identifying factors that may influence our risk of memory decline and dementia.
"Previous evidence has suggested that keeping the brain active may help boost 'cognitive reserve', allowing the brain to resist damage for longer, and this study adds to the ongoing 'use it or lose it' debate.
"It's important to note that the people in this study did not have dementia, and we can't say from these results that playing card games, reading books or doing crosswords will prevent the condition.
"The best evidence suggests that we can reduce our risk of dementia with a healthy lifestyle - eating a balanced, healthy diet, exercising regularly, not smoking, and keeping blood pressure and weight in check."
Dr Doug Brown, director of research and development at the Alzheimer's Society charity, added: "This research shows an interesting association between the size of certain brain areas, memory performance and time spent challenging the brain with games and puzzles.
"However, it doesn't tell us that playing mind-stimulating games can cause positive changes in brain volume or memory- this needs to be tested in longer term studies or clinical trials.
"Although there is no harm in playing games and puzzles, research shows that the best steps you can take to reduce your risk of developing dementia is taking regular exercise, eating a healthy balanced diet, not smoking and keeping cholesterol and blood pressure under control."