Brain blog showcase 2019: Use it or lose it: Can intellectual engagement offset cognitive decline in older age?

All this week we’re showcasing the work of students who have been “researching the headlines” as part of their undergraduate studies. Their task was to describe an original research report exploring how lifestyle affects brain health in a manner accessible to non-experts, as well as evaluating the media coverage of the research. If you’re interested in using this approach in your own teaching, you can contact Alan Gow for more information and materials.

Next up in the “brain blog” showcase, we have…

Use it or lose it: Can intellectual engagement offset cognitive decline in older age?

by Calum Anderson

The idea of using our brain effortfully, to prevent our mental abilities declining in older age is a particularly pervasive notion. Indeed, lots of people have likely heard the phrase “use it or lose it” referring to this, or will be able to understand its meaning. Intuitively, it seems to make sense. But, does this concept have adequate scientific support? Recent research suggests that engagement in intellectual activities may not actually offset cognitive decline as the ‘use it or lose it’ notion suggests.

The Research

Research led by Dr Roger Staff of NHS Grampian, and published in the British Medical Journal (BMJ), examined whether engaging in intellectual activities was associated with cognitive ability in later life, and if it protected against age-related cognitive decline. The study followed 498 participants aged 64 over 15 years, testing them on five occasions on measures of information-processing speed and verbal memory. These participants were also asked about their engagement in a range of intellectual domains, namely: reading, abstract reasoning, intellectual curiosity, and “complicated problem solving”.

The results indicated that, as expected, cognitive performance on measures of verbal memory and information-processing speed declined with age. They also showed that levels of intellectual engagement did not affect the rate of decline. However, the researchers found that higher intellectual engagement, especially in the domain of problem solving, predicted higher cognitive ability scores in later life. Thus, the researchers claimed that while increased levels of intellectual engagement might not affect how one’s mental abilities decline in older adulthood per se, it may provide a higher level from which the decline starts from.

One particular strength of the study that should be noted is that it accounts for practice effects. Thus, greater cognitive abilities in later years observed with increased intellectual engagement are not simply the result of the same people getting better at each test on subsequent attempts.

But, one must also be wary of the study’s limitations. Over the 15-year period this study covered, the number of participants dropped from 498 to 96. It’s likely that those who did not return for subsequent assessments were those most cognitively and/or physically impaired, which could limit the generalisability of the sample’s results to the wider population. Additionally, while the study shows a correlation between intellectual engagement and cognitive ability in later life, it may be that those with greater cognitive ability are those more intellectually engaged in older age, not the other way round. Finally, it’s not entirely clear what activities constitute the intellectual engagement measures used. For example, what exactly defines “complicated problem solving”? Which also raises the question: if one participant reports large jigsaws, and another brain teasers, as complicated problems they engage in, will they experience the same cognitive benefits as one another? Future work may benefit more by identifying which types of intellectual activities are most beneficial to cognitive performance.

The Media

But how did the media report these findings? Coverage of this story came from a range of sources, including a Metro article. It led with the headline: “Crosswords and sudoku puzzles ‘don’t stop dementia or mental decline’. Nowhere in the study is dementia referred to, nor did the study measure how often participants engaged in crosswords or sudoku individually – only “complicated problem solving” generally. Indeed, the only mention the research article gives to crosswords and sudoku is to say it is unclear whether these forms of activity can lead to increased brainpower. Thus, it appears the headline was written with some sensationalism.

The by-line also offers a somewhat bold claim: “People who do puzzles to try and stave off age-related mental decline may be wasting their time”. ‘Puzzles’ were not directly assessed in the study, only general problem solving. Also, while intellectual engagement may not prevent decline, it goes against the research to call it a “waste of time” if it potentially provides a higher point from which decline begins.

However, the remainder of the main article is a very good reporting of the study – largely due to the fact it is mostly copy-and-pasted from the BMJ’s press release. Thus, it covers the main findings of the study and measures used correctly, and accurately quotes the lead author of the study. Though, the article does omit mention of the BMJ, possibly preventing readers from finding the research article (which is freely available online) should they wish to view it themselves.

In Short

Whilst this research suggests intellectual engagement cannot prevent age-related mental decline, nor change its trajectory, that is not to say it is a “waste of time”. The evidence presented here suggests intellectual engagement (especially complicated problem solving) over the lifespan may provide a higher starting point from which one declines. Thus, for those who are, or have been, engaging in problem solving, it’s not been for nothing.

References

British Medical Journal. (2018). Regular problem solving does not protect against mental decline [Press release]. Retrieved from: https://www.bmj.com/company/newsroom/regular-problem-solving-does-not-protect-against-mental-decline/

Hartley-Parkinson, R. (2018, December 11). Crosswords and sudoku puzzles ‘don’t’ stop dementia or mental decline’. Metro. Retrieved from: https://metro.co.uk/2018/12/11/crosswords-sudoku-puzzles-dont-stop-dementia-mental-decline-8229491/

Staff, R. T., Hogan, M. J., Williams, D. S., & Whalley, L. J. (2018). Intellectual engagement and cognitive ability in later life (the “use it or lose it” conjecture): longitudinal, prospective study. BMJ. 363.