Mental health

Can crossword puzzles really make you smarter?


A new study from the University of Exeter Medical School has linked daily crossword puzzles with improved cognitive performance.

Researchers found that cognitive performance was consistently better in people who did crossword puzzles more frequently.

In some cases, factors like reasoning speed and short-term memory accuracy showed a brain age reduction of around 10 years in participants who frequently used crossword puzzles.

To find out more, we spoke to Dr. Henry Mahncke, CEO of Posit Science.

Posit Science is the developer of BrainHQ, a brain training program based on the science of neuroplasticity.

Is this the first study into the links between crossword puzzles and brain function?
There are actually quite a number of studies that have looked at crosswords, so this is not the first. The recent study from the University of Exeter looked at crosswords in what researchers call a “cross-sectional” study. It asks users about their personal habits, including how often they do crossword puzzles, and then looks at which personal habits are common among people with higher cognitive performance. The challenge with cross-sectional studies is they can show correlations, but don’t resolve questions of cause and effect.

Are the crossword users cognitively sharper because they do crosswords or are they more likely to do crossword puzzles because they are cognitively sharper and enjoy solving crosswords?
The most well-known work in this area has been done by Dr. Timothy Salthouse at the University of Virginia. In one of his studies, Salthouse gets to the question of causation by looking at people of different ages over time. He finds that crossword users are brighter at every age, but even though they start at a higher score, they experience the same rate of decline as the non-crossword users. He concludes that brighter people may do more crosswords because they are better at them (than less bright people), but that doing them has no protective effect to slow the rate of age-related decline.

To really sort this out, and answer the cause and effect (or “chicken or egg”) riddle, scientists do what are called “prospective randomized controlled trials.” In such a study, participants would be randomly assigned to either a crossword or a non-crossword group and tracked over time to determine if crosswords help with cognition.

One such study has been done. Researchers at the University of Iowa ran a 681-person study (the IHAMS Study), in which crosswords were used as the comparison activity against some of the computerized plasticity-based brain exercises available in BrainHQ, the exercise platform created by Posit Science, the organization I lead. Researchers found that the BrainHQ group showed significantly larger improvements in speed of processing, attention and executive function than the crossword puzzle group. The BrainHQ group also showed significantly greater improvements in everyday functioning and in standard measures of mood. That’s because people doing crossword puzzles spend most of their time in a fairly static condition of trying to think of a word, while BrainHQ users are continuously challenged with dynamically-adjusted exercises to improve the speed and accuracy of information processing in the brain, by continuously pushing users to a new personal best.

How are this study and the results different/new?
The results are consistent with earlier cross-sectional study showing brighter people do more crosswords.

Does it matter if the crossword is on your phone or in print?
No. It’s unlikely in my view that either type improve cognitive function.

Are crosswords puzzles the only way to improve brain function or will any puzzle type activity help?
The literature consistently shows a correlation between being brighter and liking solving puzzles; however, that is not cause and effect. No study shows that doing crosswords or other such puzzles makes you better at anything other than doing those tasks. Last month, the National Academies of Science, Engineering, and Medicine (NASEM) confirmed that there are a three things you can do that do seem to work:

(1) Brain Training – NASEM noted that the literature increasingly shows evidence that scientifically-designed computerized training has positive effects on brain function. In particular, they cited the speed of processing training used in the ACTIVE study, which generalized to not just improvements in cognition, but also in mood and everyday functions. Ten years ago, that technology was acquired and with the help of its inventors, it was incorporated into BrainHQ.

(2) Physical Exercise – While results from studies on the impact of physical exercise on the brain are mixed, most scientists believe that what is good for the heart is good for the brain, even if the effect sizes are not large.

(3) Blood Pressure – High blood pressure has negative impact on many areas of the body over time. It is believed that it also has an adverse impact on the brain, so NASEM recommends those with high blood pressure should take their hypertension medication to maintain their blood pressure in the normal range.

How exactly do crossword puzzles affect the brain?
Crosswords place demands on a particular cognitive skill called “fluency” – that’s what you and I might call “finding the right word.” I am among scientists who believe that the key cognitive deficit of aging is a well-documented slowing in processing speed as people age. That slowing, by a couple seconds or even a tenth of a second, can throw off your ability to collect, store and retrieve information every waking moment of the day, with all sorts of negative consequences. When you can’t find a word, often you think of it a few minutes or even a day later. The real problem we want to solve is making you quicker, so you can come up with that word in the moment you need it. Crosswords are not particularly designed to have you come up with the word in the moment. On the other hand, BrainHQ exercises that emphasize processing speed have been shown to help with verbal memory, including in one study of nearly 500 older adults led by researchers at the Mayo Clinic and USC.

What can you tell us about the links between dementia and cognitive decline?
There is a growing consensus that there is a continuum from age-related decline to pre-dementia and dementia, and that getting dementia is not genetically pre-ordained. Taking steps that make your heart and brains healthier organs (such as diet and physical exercise) is a good idea. This should include getting adequate sleep and appropriately managing stress. Of course, we think the most direct approach is the right kind of brain exercises, meaning those shown is peer-reviewed studies to drive improvements in cognition and everyday activities. A recent literature review of commercially-available brain apps found only BrainHQ exercises have shown these results in multiple high quality studies.

How many minutes of brain exercise per day should we aim for? Does it have to be daily to be effective?
One big difference between brain exercise and physical exercise is that getting significant and noticeable gains from brain exercises takes a lot less time, and the effects dissipate much more slowly that when you stop physical exercise. Most of the studies of the benefits of BrainHQ exercises for older adults involved only 10 to 40 hours of training. For example, the highly-regarded ACTIVE Study, which tracked more than 2,800 older adults engaged in different types of cognitive training for 10 years (as people on average aged from 74 to 84) asked most people only to complete 10 hours of training at the beginning of the study (2 hours per week for five weeks), and had benefits that persisted ten years later. A subset who were asked to do an additional eight hours of training, had better results, so we believe more is better (within reason). We generally recommend getting in 90 minutes of exercise a week in multiple sessions (of as little as five minutes). If you are going on vacation, or your life gets busy, it’s okay to take a break, but you should get back to it or the benefits will dissipate over time. We also suggest that kind of schedule because most of us have chunks of as little as five minutes several times every day when we could do brain exercises on our phones, tablets or computers.

We all complain of being time poor (to find time in our day to do this brain practice). In your view, what should the average person stop doing (i.e. watching tv?/ sleeping?)
TV, even educational TV, is a largely passive activity for the brain. You may enjoy it, and you may learn things, but it is not pushing your brain to its threshold of performance, nor pushing you to achieve any new personal best. Anytime you take up a new and challenging skill, you brain is being pushed in ways that should make it healthier. Properly designed brain exercises also do this, but in a more efficient way. Sleep is important to consolidate gains in cognition from one day to another.

What else can you tell us about brain function that you think people should know?
I work with the leaders in the field of lifelong brain plasticity and have been a principal investigator in a number of studies myself. My colleagues demonstrated 30 years ago that the brain actually changes chemically, structurally and functionally based on sensory and other inputs throughout life. At first, this proposition was dismissed by experts; then, after it had been shown repeatedly in experiments, it became the subject of debate, and, about 20 years ago, it became the new consensus. We are in a similar process about the effectiveness of plasticity-based brain training. As the recent NASEM report indicates, there is now an emerging consensus that properly-designed brain training works.

Nearly 20 years ago, my colleagues decided that we had run enough experiments that made rats and monkeys smarter, and it was time to apply what we knew about brain plasticity to training programs for humans. Because we can create software that measures your response and then can adjust the stimuli continuously (based on your history of responses), we can build computer programs that personalize in minutes and that very efficiently drive positive changes in the brain. More than 150 peer-reviewed papers have been published on the exercises and assessments in BrainHQ and they show gains across standard measures of cognition (e.g., speed, attention, memory, reasoning) that also generalize to mood and everyday activities. That’s because the exercises are based on those earlier experiments that proved brain plasticity exists throughout life and throughout the brain. The exercises are designed to break cognition down into its most elemental parts and then drive incremental gains that aggregate into improvements in higher cognition and life.

New brain imaging techniques are increasingly confirming that the changes we see functionally are a result of underlying changes in chemistry and brain structure. Having worked in this field for decades, I can say that every month we are seeing acceleration in our understanding of the brain.

Anything in the research that may surprise people?
While we’ve suspected for some time that physical exercise may help with cognition, one set of study results that often surprises people is that researchers showed that BrainHQ exercises can help with physical movement. A pair of studies from the University of Illinois at Chicago showed that BrainHQ visual training helped with balance and gait in older adults on the cusp of high fall risk. That’s because the visual-spatial and visual-motor systems work with your vestibular (inner ear) system to help you control movement. Or, more simply put, the mind controls the body.

While most of our discussion has been about age-related cognitive decline, we actually do a fair amount of work with top performers interested in improving their peak performance. After all, being faster and more accurate helps with a tremendous number of human endeavors. For example, we work with top executives, financial traders, law enforcement, the military, professional card players, heavy equipment operators, and quite a number of professional and Olympic athletes and teams.

Megan Houston

Balance website, community and content manager. Email

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