This story was originally published in our Jul/Aug 2023 issue as “Mind Games.” Click here to subscribe to read more stories like this one.

I’m slouching over my desk, smartphone in hand, furiously tapping at the screen. In a game that looks straight out of a 1980s Atari console, I’m trying to direct little multicolored trains to stations of the same color by selecting the tracks as fast as I can. This task is supposed to assess my attention skills. I don’t do well. Luckily for me, the app promises I can improve with training, for as little as $11.99 per month.

I’m not the only one tempted to level up my mental fitness and keep my brain healthy with just a bit of screen time. In recent years, the idea that online games can boost cognitive flexibility has gained widespread appeal, giving rise to a huge brain training industry worth upwards of $6 billion. (It’s projected to grow to $44 billion by 2030, according to a 2022 market research report by InsightAce Analytic.) These days, new apps pop up faster than zombies in shooter games, promising to improve your problem-solving capabilities, memory and processing speed — essentially making you smarter, sharper and more mentally agile. All you have to do is carve out a few minutes each day to solve simple puzzles and memory games, like matching cards, arranging the tiles of a mosaic or solving math equations.

At least, that’s the idea. Many developers of brain-training apps say that their products are firmly rooted in science. BrainHQ, for example, offers 29 online exercises “built on serious science” and asserts that its cognitive benefits are proven in at least 100 published studies. Another app, HAPPYneuron, states it’s “a part of therapy for a variety of medical conditions,” listing a wide range of issues, from healthy aging and Alzheimer’s disease to stroke and multiple sclerosis — even distinct psychiatric conditions like schizophrenia, bipolar disorder and depression. Since its launch in 2007, more than 100 million people worldwide have used Lumosity, which claims to offer “statistically significant improvements” for a host of cognitive assessments. And many people find those claims compelling; a survey of over 3,000 Americans found that a majority believe brain-training apps help them with thinking, attention and memory, according to a paper published in Frontiers in Human Neuroscience in 2016.

Research, however, paints a more complicated picture. “Many of the brain training companies essentially have no evidence in support of their particular programs having those sorts of real-world benefits,” says Daniel Simons, an experimental psychologist at University of Illinois; Simons led a team of experts that conducted one of the most extensive reviews of scientific studies about brain-training apps to date. Several other meta-analyses and reviews came to similar conclusions: A 2022 review, for instance, stated that online brain training may be fun, but there is little evidence that it helps everyday functioning. Fernand Gobet, cognitive scientist at London School of Economics and Political Science, and author of several meta-analyses on cognitive training, sums it up bluntly: “I’m very confident there is no effect.”

While it’s certainly possible to boost our mental capabilities, many studies on brain-training apps have so far fallen short at proving the games’ ability to hyper-charge our brains in ways that actually matter. Research on such apps, experts argue, is riddled with methodological problems, from small sample sizes to cherry-picking of evidence. And if you really want a stronger, sharper brain, there may be better ways to flex those mental muscles.

There’s nothing new about humans trying to train their brains — we’ve been playing with this idea since ancient times, if not before. Plato, for example, believed that practicing arithmetic could boost general intelligence. In the early Middle Ages, a collection of brain teasers, believed to have been compiled by an Anglo-Saxon scholar named Alcuin of York, were used to sharpen young minds. (You may have heard of one of these puzzles, in which you have one boat and have to safely transport a wolf, a goat and a cabbage across a river). In the early 20th century, one of the first widely available examples of commercial brain training — a program called Pelmanism, which included a small booklet and a card game — garnered over half a million practitioners.

Modern science shows that it is indeed possible to boost brain power. “You can improve it in young children, you can improve it in octogenarians. It seems to be possible at every age,” says Adele Diamond, neuroscientist at the University of British Columbia. The “it” in question is executive function — a group of interrelated, higher-level processes that enable us to plan, focus our attention, achieve our goals and more. (See sidebar on page 53.) Taken together, “executive functions are important for mental and physical health, for doing well in school and on the job, for getting along with others and having marital harmony,” says Diamond. “It’s hard to think of any aspect of life that executive functions are not important for.”

Given the potential benefits, researchers decided to check whether it’s possible to strengthen those skills with simple online games. The early results were promising: In 2002, Swedish scientists suggested that playing a basic computer game could boost working memory both in children with attention deficit hyperactivity disorder (ADHD) and in healthy adults. Soon, a flurry of experiments followed, and so did the number of available commercial products.

Of course, quantity doesn’t always equal quality. The 2002 study was far from perfect; first and foremost, it was tiny, with only 14 children and just four adults. With such small samples, spurious findings are common, Simons says. In their 2016 review of studies on brain-training apps, Simons and his colleagues listed pages upon pages of design and methodology issues plaguing this type of research.

Apart from small samples, there’s also the issue of expectation bias. “In a drug study, if somebody doesn’t know whether they’re getting the drug or a placebo, they have no difference in expectations for what’s going to improve,” says Simons. “In most of the brain training studies, people know what it is that they’re practicing, and they have predictions about what will improve and what won’t. And as a result of that, they might report improving on those things that they think should improve.”

What’s more, many studies on brain-training apps include only self-evaluations for real-world outcomes — essentially, people are asked to report whether they think their memory or attention have improved. In a 2022 meta-analysis of studies on brain training, which included data on seven programs including BrainGymmer, BrainHQ, CogMed and Lumosity, participants reported some positive effects, but most such benefits disappeared if objective measures, such as cognitive tests, were considered instead. In his 2023 review, published in Perspectives on Psychological Science, Gobet also points to the placebo effect and reliance on self-evaluations as issues plaguing research on cognitive training.

And then there’s the potential for cherry-picking of evidence. Imagine you’re running a study on a cognitive-training app. Your volunteers use the app, then take tests of working memory, attention, general intelligence, and so on, but show no improvements, apart from a tiny boost in their speed of processing. So you publish a scientific article only on speed of processing and don’t mention the other negative results. According to Simons, underreporting of outcome measures may be quite common in cognitive training research. “Very few of those studies have posted all their data or all of their experimental materials,” he says. What’s more, basic statistics indicates that some such limited positive results may occur randomly, rather than as a result of the training.

Some representatives of brain training companies agree that quality of brain-training programs is mixed at best, which, they say, casts a negative light on all such products, obscuring the real picture. “It’s like lumping snake oil with antibiotics and then saying on average nothing works, so we shouldn’t bother to treat tuberculosis,” says Henry Mahncke, CEO of Posit Science. Indeed, one 2017 review showed that programs developed by Posit Science, such as BrainHQ, had the highest-quality evidence for the potential to lower the risk of cognitive decline in older adults.

Still, many studies that developers present as a proof that their products boost cognitive performance have one thing in common: They have been either directly funded by app developers or conducted by researchers with ties to them. “You always have to be a little worried when the company that is sponsoring the study has a vested interest in the outcome,” Simons says.

It makes sense that companies offering brain training may want to sponsor research to check whether their products really work. But research on the pharmaceutical and nutrition industries shows that studies with financial links to the industry are more likely to have outcomes favorable to that industry — a phenomenon known as the funding effect. An analysis of 206 nutrition-related journal articles, for example, revealed that for sponsored papers, an outcome favorable to the sponsor was about four to eight times more likely than for articles that weren’t sponsored.

Another major issue with research on brain-training apps is due to the absence of something scientists call far transfer, or a lack of results in real life. “You can practice something repeatedly, and you are going to get better at that thing. That part is pretty indisputable,” says Thomas Redick, a cognitive psychologist at Purdue University. “Where I have been skeptical, and I don’t think I’m alone in this, is the sort of further reaching claims of, ‘This is an alternative treatment for ADHD’ or ‘This is increasing your IQ.’ ”

In other words, if I play the train exercise a lot, I’ll almost certainly get better at it. Yet it’s doubtful that the game will actually make me better at, say, multitasking while doing chores. In fact, a 2018 study showed that when volunteers trained on an online memory game, they improved at that particular game, but scored about the same as a control group on a different memory test. “The kind of transfer [app developers] talk about is, ‘Your kids are going to be better at mathematics; you are going to be more intelligent; if you are older, you won’t suffer from Alzheimer’s,’” Gobet says. “These strong claims require very strong evidence. But not only is there no strong evidence, there is no evidence at all when all studies are considered together.”

The far transfer conundrum has bothered scientists for well over a century. Back in 1906, American psychologist Edward Thorndike showed in his experiments that when students practiced estimating the area of rectangles, they got better at it. However, this ability didn’t make them any better at estimating the areas of other shapes, like triangles. It is simply hard to transfer skills from one domain to another, and the more distant they are, the harder it becomes. Fortunately, there are other, science-backed ways to boost our brains in everyday life — no smartphone required.

Different Ideas, Different Perspectives

Researchers like Diamond believe that the key to improving our cognitive function is through real-world experiences. In a 2020 review of 179 studies from all over the world, Diamond and her colleague showed that activities such as tai chi and taekwondo are particularly promising in revving up our brain power. “These are great ways to reduce stress, and we know that stress seriously impairs executive function,” she says. What’s more, martial arts can train some cognitive functions directly, too, such as inhibitory control — like when you have to wait patiently for a good moment to attack your opponent.

Other studies have also shown that physical activity, giving up smoking and healthy sleep habits can be good ways to boost executive function. When scientists from the University of Oxford looked at biomedical data of almost half a million British people, they discovered that those who sleep between six to eight hours a day have more gray matter volume in several areas of their brains, including the orbitofrontal cortex, which participates in learning and decision-making, and the hippocampus, which plays a major role in memory.

Besides general lifestyle tweaks, engaging in hobbies and things you are passionate about may be the best way to keep your mind sharp, whether you choose gardening, cooking or volunteering. Researchers have found that dance and music have cognitive benefits, too. One 2017 study analyzing the effects of a music education program developed in Venezuela revealed that children who participated benefited greatly in terms of executive function, as well as standardized test scores and math grades. The program not only taught them how to play an instrument, but also provided opportunities to rehearse with a school orchestra.

Regardless, the key to a hobby that carries mind-sharpening benefits, says Diamond, is to pick something that challenges you. “If you always make the same dish then you’re no longer challenging executive functions — and so it won’t work. It has to be something that you can’t just do [automatically],” she adds.

Novelty and challenge may be the reasons why multicultural experiences, travel included, can also keep our brains in good form. A 2014 study conducted in Taiwan, for instance, showed that children who grow up in multicultural families outperform monocultural kids on a battery of tests that measure creativity and problem solving, while other studies show that people who have spent at least a few months living abroad excel at various measures of cognitive flexibility.

Still, flying to Cancun for a week of sun and sand is not going to rewire your brain. To get the cognitive benefits of multiculturalism, you really need to challenge yourself by actively engaging with other cultures. “Different ideas, different perspectives, different ways of looking at things — it changes the complexity of your brain,” says William Maddux, professor of organizational behavior at University of North Carolina.

Meanwhile, for Simons, there’s nothing inherently wrong or dangerous about brain-training apps. “But you have to pay money for them, and you have to spend your time doing them. It’s the opportunity cost of playing a game versus doing something else.”

It’s also important to be cautious of overstated claims by developers. In 2016, the creators of Lumosity paid $2 million to settle Federal Trade Commission’s deceptive advertising charges for unfounded claims that their games help people perform better at work and delay cognitive aging.

Nonetheless, for certain people, brain-training apps could someday offer hope for cognitive improvement they may not be able to get elsewhere. According to Julia Karbach, a psychologist at University of Kaiserslautern-Landau, Germany, brain-training apps have the potential to benefit those who are bed-ridden due to illness, stroke or agoraphobia. Meanwhile, those suffering from Alzheimer’s disease and dementia might find it easier to reach for an app than, say, sign up for tai chi. In 2021, the National Institutes of Health granted the University of South Florida over $44 million to study whether dementia risk could be lowered through the use of computerized brain training.

With 5.8 million Americans now living with Alzheimer’s disease, any potential tool in our arsenal to fight mental decline is certainly welcome — even if its effects are limited to training rather narrow skills.

Exploring Executive Functions

The term executive functions refers to a set of cognitive processes and mental skills that help you control and coordinate your other cognitive abilities and behavior. (Think of them like an executive monitoring all the departments within their company, or an air traffic control system helping planes take off and land on different runways while avoiding mid-air collisions.) You use these skills every day to plan ahead, meet goals, exhibit self-control, follow directions, stay focused and more.

Here are the three main executive functions that allow you to succeed — and thrive — in everyday life.

Cognitive flexibility: Also known as thinking outside the box, this refers to the ability to see problems from different angles — and adapt your behavior and thinking to new situations.

Inhibitory control: This executive function is all about self-control, ignoring distractions and not acting impulsively. Essentially, it’s the ability to think before you react.

Working memory: This ability allows you to hold information in your mind without losing track of it — for example, when you try to solve a math problem. It’s your brain’s version of a sticky note.