Brain Training Research: What Studies Actually Show

The promise sounds almost too good to be true: spend a few minutes daily playing brain games on your phone, and you'll get smarter, prevent dementia, and perform better at work. Millions of people have downloaded brain training apps hoping for exactly these benefits. The industry has grown into a multi-billion-dollar market built on the premise that targeted cognitive exercises can reshape your brain and transform your mental abilities.

But what does the actual research show? The answer is more complicated—and more honest—than most marketing claims suggest.

Brain training does improve performance on the specific tasks you practice. That much is clear and uncontroversial. The real question scientists have been debating for decades is whether those improvements transfer to other cognitive abilities and real-world activities. Do memory games make you better at remembering where you put your keys? Does attention training help you focus at work? Will any of this prevent cognitive decline as you age?

After thousands of studies, billions in consumer spending, and fierce debate among neuroscientists, we finally have enough evidence to answer these questions honestly. The conclusions won't satisfy marketers on either side of the debate, but they'll give you the truth about what brain training can and cannot do for you.

A Field Divided by Standards of Evidence

The scientific community's most public split came in October 2014, when the Stanford Center on Longevity and the Max Planck Institute for Human Development released a consensus statement signed by 70 leading cognitive psychologists and neuroscientists. Their conclusion was blunt: the scientific literature does not support claims that software-based brain games alter neural functioning in ways that improve general cognitive performance in everyday life or prevent cognitive slowing and brain disease.

Within weeks, 133 scientists and practitioners fired back with their own statement. They insisted there is "a large and growing body of evidence" showing certain brain exercises improve cognitive function in ways that generalize to everyday life. The signatories included respected researchers from universities worldwide, all arguing that dismissing cognitive training was premature.

So who's right? The uncomfortable answer is that both groups were partially correct, but they were evaluating different evidence standards. The skeptics demanded proof of meaningful real-world improvements using rigorous experimental controls—the gold standard of scientific evidence. The proponents pointed to the existence of positive findings in the published literature, even if those studies had methodological weaknesses.

The gap between these positions has narrowed considerably since 2014. Comprehensive meta-analyses examining all available evidence have largely vindicated the skeptical position when it comes to far transfer, while confirming that near transfer reliably occurs. The most thorough independent review came in 2016, when Daniel Simons and colleagues published their analysis in Psychological Science in the Public Interest. They examined all peer-reviewed studies cited by major brain training proponents and concluded there is "little evidence that training enhances performance on distantly related tasks or that training improves everyday cognitive performance."

This doesn't mean the debate is over. But it does mean we now have enough high-quality evidence to distinguish between what's proven, what's plausible, and what's wishful thinking.

Understanding Transfer Changes Everything

The entire brain training debate hinges on a concept that sounds technical but is actually quite simple: transfer. Understanding this concept is essential to making sense of conflicting claims about whether brain training "works."

Transfer refers to whether improvements from training on one task carry over to other tasks or real-world activities. Scientists distinguish between two types, and the difference between them explains most of the confusion in public discussions about brain training.

Near transfer means you get better at tasks similar to what you practiced. If you train on a digit-span memory task where you try to remember increasingly long strings of numbers, near transfer would mean you can now remember longer phone numbers. The tasks are fundamentally similar—they both involve holding sequences of digits in mind. Research consistently shows near transfer occurs with brain training, typically producing small to moderate improvements. Nobody disputes this.

Far transfer is the holy grail that would make brain training genuinely transformative. This is when training on one type of task improves completely different cognitive abilities. If practicing working memory games made you better at reading comprehension, mathematical reasoning, or focusing during meetings, that would be far transfer. It's what most marketing claims implicitly promise and what most consumers actually want.

The evidence for far transfer is where things fall apart. A landmark analysis by Giovanni Sala and Fernand Gobet examined results across 99 to 119 separate meta-analyses covering thousands of studies on working memory training, video games, music training, and chess. Their conclusion was stark: when studies use proper methodology, "the real effect size of cognitive training on far transfer is zero."

This finding held across different populations—healthy adults, children, older adults, and clinical groups. It held across different types of training—computerized brain games, action video games, strategy games, and music instruction. The pattern was consistent and clear: people reliably get better at what they practice, but those gains rarely spread to other cognitive abilities.

Why doesn't far transfer happen? The researchers describe it as "an invariant of human cognition"—a fundamental constraint on how learning works. Our brains are more specialized than we'd like to believe. Becoming an expert chess player doesn't make you better at mathematics, even though both involve strategy and planning. Training spatial memory doesn't improve verbal memory. Practicing attention tasks doesn't enhance reasoning ability. Skills are domain-specific, and that limitation appears difficult or impossible to overcome through targeted training alone.

The Placebo Effect Is Larger Than You'd Think

One of the most sobering discoveries in brain training research came from a cleverly designed experiment published in the Proceedings of the National Academy of Sciences in 2016. Researchers recruited participants using two different flyers—one promised "brain training and cognitive enhancement," while the other neutrally sought research subjects without mentioning any benefits.

Both groups received identical training: just one hour of working memory practice using n-back tasks, which are among the most heavily researched brain training exercises. When tested afterward, participants recruited with the suggestive flyer showed improvements equivalent to five to ten IQ points. The other group showed minimal gains. Same training, different expectations, dramatically different results.

This finding reveals a fundamental problem contaminating brain training research. When people believe training will help them—and most study volunteers self-select precisely because they believe it might work—they perform better on post-tests for reasons completely unrelated to the training itself. They're more motivated, they try harder, they're less anxious during testing. These expectancy effects can be powerful enough to create the illusion of cognitive enhancement where none actually exists.

The solution is to use "active control" groups—participants who do an engaging alternative activity and believe it might help them just as much as the intervention group believes their training will help. When studies use these proper controls rather than comparing brain training to doing nothing, the apparent benefits largely disappear. A systematic review found that 90 percent of studies without active controls reported positive effects on far transfer, but those effects shrank dramatically or vanished when researchers controlled for expectancy.

This doesn't mean all positive findings are pure placebo. But it does mean we should be extremely skeptical of studies that don't control for expectancy effects, and that includes many of the studies cited in brain training marketing materials.

The ACTIVE Study Stands Out—With Important Caveats

Among thousands of brain training studies, one towers above the rest in terms of scale, duration, and scientific rigor. The Advanced Cognitive Training for Independent and Vital Elderly study—universally known as ACTIVE—remains the largest and longest randomized controlled trial ever conducted on cognitive training.

The study followed 2,832 older adults across six U.S. cities for 10 years. Participants were randomly assigned to one of four groups: memory training, reasoning training, processing speed training, or a no-contact control group. The findings were genuinely impressive, particularly for processing speed training.

Eighty-seven percent of participants in the speed training group showed meaningful improvement on processing tasks immediately after training. Perhaps more remarkably, benefits persisted when researchers checked back at five and ten years later. The speed training group also reported better performance in daily activities like managing money, preparing meals, and housekeeping compared to the control group.

Most notably, a 2017 follow-up analysis found a 29 percent reduction in dementia risk among participants who completed the most speed training sessions. For a non-pharmaceutical intervention, this would be remarkable if true.

But responsible interpretation requires understanding several critical limitations that often get glossed over when the ACTIVE study is cited as proof that brain training works.

First, the dementia finding was what scientists call a secondary post-hoc analysis. The study wasn't originally designed to measure dementia risk—that question was added after the fact when researchers decided to look at the data in a new way. The result was barely statistically significant, used algorithmic criteria rather than clinical diagnosis, and an earlier analysis at the five-year mark found no dementia effect. Most importantly, no independent research team has replicated this finding. Several of the lead researchers also have financial relationships with companies that market speed-of-processing training, which doesn't invalidate the research but does require additional scrutiny.

Second, the study used no-contact control groups—people who received no intervention at all. This makes it impossible to separate genuine training effects from placebo effects, benefits from social engagement, or simply the experience of doing any mentally stimulating activity with supportive staff. We can't know whether the improvements came from the specific training tasks or just from the experience of participating in something.

Third, the self-reported improvements in daily functioning may reflect changed perceptions rather than actual ability changes. When researchers used objective performance-based measures of everyday function, the benefits were less clear.

Despite these caveats, the ACTIVE study does provide evidence that processing speed training produces durable improvements on trained tasks and possibly some real-world benefits, particularly for activities like driving that depend on quick visual processing. A 40 to 50 percent reduction in at-fault car crashes and delayed driving cessation are meaningful outcomes if they hold up in further research.

Different Types of Training Show Different Results

Not all brain training is created equal. The evidence varies dramatically depending on what type of cognitive ability you're trying to train.

Processing Speed: The Strongest Case

Speed-of-processing training—particularly the Useful Field of View tasks used in the ACTIVE study and now marketed commercially as Double Decision in BrainHQ—has the most compelling research support of any brain training approach. Effect sizes on trained measures reach extremely large levels, benefits persist for a decade or more, and there's genuine evidence of transfer to real-world activities like safer driving.

Why might speed training succeed where other approaches fail? One theory is that processing speed acts as a fundamental bottleneck in cognition. If you can process information faster, that improvement may cascade through multiple cognitive operations that depend on speed. Remembering something requires you to process and encode it quickly enough before it fades. Reasoning requires you to hold and manipulate information before it decays. If speed training genuinely increases how quickly you can process information, the benefits might naturally spread to other cognitive tasks in ways that pure memory training or reasoning training cannot.

This remains a theory, and even processing speed training doesn't produce the dramatic, across-the-board cognitive enhancement that marketing often implies. But the evidence is stronger than for other training types.

Working Memory: The Disappointing Reality

Working memory training—particularly n-back tasks where you try to remember items from several steps back in a sequence—generated enormous excitement after a 2008 study by Susanne Jaeggi claimed it improved fluid intelligence, the ability to solve novel problems. If true, this would be transformative: a simple computerized task that makes you genuinely smarter.

Subsequent research has been far less encouraging. A comprehensive meta-analysis published in 2016 examined 87 publications with 145 experimental comparisons. The results showed substantial near transfer to other working memory tasks—people did get better at remembering things temporarily. But for far transfer to intelligence, reading, or arithmetic, researchers found "no convincing evidence of any reliable improvements" when studies properly controlled for expectancy effects.

The working memory training debate continues, with Jaeggi and colleagues arguing that the case isn't closed and that certain training conditions might still produce far transfer. But statistical techniques designed to detect whether published positive findings represent genuine effects or publication bias showed "no evidential value" in the working memory training literature when studies used proper controls.

The most likely explanation is that early positive findings reflected a combination of publication bias, expectancy effects, and statistical flukes that didn't replicate when researchers used more rigorous methods.

Memory Training: Limited and Short-Lived

In the ACTIVE study, memory training produced the weakest and least durable effects among the three training types. While 26 percent of participants showed immediate improvement, effects faded away over the ten-year follow-up period, unlike reasoning and speed training which maintained benefits. Memory training showed no significant reduction in dementia risk.

This doesn't mean you can't improve your memory through training. Mnemonic techniques like the Method of Loci—the "memory palace" technique—do produce substantial improvements in your ability to memorize lists. But these are strategy training, not capacity enhancement. You're learning clever techniques for organizing information, not expanding the underlying capacity of your memory systems. Those techniques work for specific types of memory tasks but don't boost your general memory ability across different situations.

Attention and Executive Function: Modest at Best

Training focused on attention and executive functions like task-switching shows mixed results. Action video game training has received substantial research attention, with some evidence for improvements in visual attention and spatial cognition. But comprehensive analyses suggest publication bias inflates reported effect sizes by roughly 30 percent, and transfer to real-world outcomes beyond gaming performance remains limited.

Task-switching training shows some evidence of near transfer and occasionally produces hints of far transfer in specific populations like children or older adults, but effect sizes are modest and findings are inconsistent. Overall, training focused on executive functions produces smaller and less reliable benefits than processing speed training.

Different People Respond Differently

The evidence for brain training also varies dramatically depending on who's doing the training.

Healthy Younger Adults: Minimal Meaningful Benefits

If you're a cognitively healthy person under age 60, the evidence for meaningful brain training benefits is weakest. The largest study in healthy adults—a massive BBC experiment with 11,430 participants—found that despite clear improvements on trained tasks, there was "no evidence for transfer effects to untrained tasks, even when those tasks were cognitively closely related."

The likely reason is ceiling effects. If your brain is already functioning well, there's less room for improvement through targeted training. The gains you might achieve on specific tasks don't translate to better real-world cognitive performance because you were already performing those activities adequately.

Older Adults: The Best-Supported Use Case

Research most strongly supports brain training for healthy older adults, roughly age 65 and up. The ACTIVE study provides the highest-quality evidence we have for this population, showing that processing speed training produces benefits that last for years and may transfer to everyday activities.

Meta-analyses examining multiple studies show overall small-to-moderate effects across different types of cognitive training in older adults. Supervised training appears more effective than unsupervised practice, and periodic booster sessions help maintain benefits over time. For older adults concerned about maintaining cognitive function, the evidence is strong enough to justify trying brain training—with realistic expectations focused on maintaining abilities rather than dramatic enhancement.

Children with ADHD: Memory Gains Without Symptom Relief

Parents hoping brain training might help children with attention-deficit/hyperactivity disorder should understand a crucial distinction: improving working memory doesn't reduce ADHD symptoms.

Multiple meta-analyses examining working memory training in children with ADHD show a consistent pattern. Training produces substantial improvements on working memory tasks—effect sizes are often large, suggesting kids genuinely get better at holding information in mind. But when researchers measure actual ADHD symptoms using evaluations by teachers or clinicians who don't know which children received training, the effects are negligible.

Cogmed, the leading commercial program for ADHD, illustrates this gap perfectly. It produces large improvements on working memory tasks but near-zero effects on academic achievement, attention in class, executive function, or intelligence. As researchers concluded: "The only unequivocal statement is that Cogmed will improve performance on tasks resembling Cogmed training."

For context, ADHD medications produce effect sizes of 0.8 to 1.0 on symptom measures—dramatically larger than the near-zero effects seen with working memory training. Brain training is not a viable substitute for evidence-based ADHD treatments.

Mild Cognitive Impairment: Uncertain Benefits

For people experiencing mild cognitive impairment—the stage between normal aging and dementia—the evidence remains unclear. Cochrane reviews examining computerized cognitive training for MCI concluded the evidence quality is "very low" and researchers "cannot determine" whether training prevents progression to dementia.

Some studies suggest moderate improvements in verbal memory and working memory among people with MCI, but these findings are preliminary. Larger, longer studies are needed before we can know whether training provides meaningful benefits for this population.

Dementia: Evidence Does Not Support Benefits

For people already diagnosed with dementia, Cochrane systematic reviews found "no evidence to support cognitive training for any examined outcome." The cognitive systems are too impaired for targeted training to produce measurable benefits.

Cognitive stimulation therapy—social group activities engaging the brain through discussion, reminiscence, and varied activities—shows better evidence than computerized training for people with dementia. The social engagement and varied stimulation appear more beneficial than repetitive computerized tasks.

The Marketing-Evidence Gap

Understanding what research actually shows makes the gap between marketing claims and scientific evidence starkly clear.

What the FTC Says

In January 2016, the Federal Trade Commission settled charges against Lumos Labs, maker of Lumosity, for deceptive advertising. The company paid a $2 million fine (reduced from a $50 million judgment due to inability to pay) and was prohibited from making certain claims about their products.

The FTC found Lumosity had falsely claimed that games would delay memory decline and protect against dementia and Alzheimer's disease. They claimed without adequate evidence that games improved school, work, and athletic performance. The company purchased Google ads targeting searches for "dementia" and "Alzheimer's disease," steering vulnerable people to unproven products. They failed to disclose that testimonials came from contests offering free iPads and trips rather than genuine user experiences.

The FTC's statement was blunt: "Lumosity preyed on consumers' fears about age-related cognitive decline, suggesting their games could stave off memory loss, dementia, and even Alzheimer's disease. But Lumosity simply did not have the science to back up its ads."

Similar enforcement actions followed against other companies making unsupported claims about treating ADHD, autism, traumatic brain injury, and other conditions.

Claims Science Doesn't Support

Based on rigorous research, these common claims lack scientific backing:

Brain games prevent or reverse Alzheimer's disease or dementia. The evidence doesn't support this. The most promising finding—the 29 percent dementia risk reduction in the ACTIVE study—was a secondary analysis that hasn't been replicated and had significant methodological limitations.

Training produces permanent cognitive improvements. All evidence shows benefits require ongoing practice and fade when training stops, much like physical fitness requires continued exercise.

Brief daily training improves general intelligence. Meta-analyses controlling for expectancy effects and publication bias show no reliable far transfer to fluid intelligence from any type of brain training.

Brain games enhance real-world job or academic performance. Studies using objective performance measures find minimal or no transfer to work or school outcomes.

Training works as well as medication for ADHD or other conditions. Effect sizes for brain training on ADHD symptoms are near zero when properly measured, while medications show large effects.

What Evidence Actually Supports

Research does support these more modest claims:

Training improves performance on trained tasks and very similar tasks. Near transfer is real and consistent across studies.

Processing speed training shows durable benefits for older adults. The ACTIVE study provides genuine evidence for maintained effects over a decade, primarily for speed-of-processing training specifically.

Some programs may help maintain cognitive abilities with long-term consistent use. For older adults, regular engagement with challenging cognitive activities appears beneficial for maintaining function, though whether computerized training is superior to other mentally stimulating activities remains unclear.

Any mentally engaging activity is preferable to passive sedentary behavior. Brain training likely provides more cognitive stimulation than watching television, though whether it's better than reading, social engagement, or learning new skills in the real world is questionable.

What Should You Actually Do?

The research leads to practical conclusions that won't satisfy people looking for simple answers, but they're honest.

For Healthy Younger Adults

If you're under 60 and cognitively healthy, evidence suggests minimal meaningful benefit from brain training. Your time and money are probably better invested in physical exercise, learning new skills like languages or musical instruments, maintaining social connections, or pursuing cognitively challenging hobbies that come with additional real-world benefits.

Reading complex material, engaging in substantive conversations, taking courses, solving real-world problems—all of these provide cognitive stimulation without the limitations of artificial training tasks. The added benefit is that improvements in these activities have direct value in your life beyond the cognitive exercise itself.

For Healthy Older Adults

If you're 65 or older and concerned about maintaining cognitive function, processing speed training has the strongest evidence base. Programs based on the Useful Field of View paradigm from the ACTIVE study—commercially available as BrainHQ's Double Decision—showed maintained benefits over ten years and possible (though unconfirmed) dementia risk reduction.

If you choose to use brain training, consistent practice over months or years with periodic booster sessions appears more effective than short-term intensive training. Set realistic expectations: anticipate improvement on trained tasks and possible benefits for activities like driving that depend on quick visual processing, but don't expect dramatic cognitive transformation.

Importantly, don't neglect other approaches with evidence just as strong or stronger. Aerobic exercise shows consistent cognitive benefits in aging adults. Social engagement, intellectually stimulating hobbies, adequate sleep, and cardiovascular health management all have substantial supporting evidence.

For Parents of Children with ADHD

Working memory training is not a substitute for evidence-based ADHD treatments. While training improves working memory task performance, it doesn't reduce ADHD symptoms or improve real-world functioning in ways that matter for children's daily lives.

Behavioral interventions, school accommodations, and when appropriate, medication all have much stronger evidence for actually helping children with ADHD. Brain training might provide some modest benefits as one component of comprehensive treatment, but it shouldn't be the primary intervention or replace approaches that genuinely help.

For Anyone Concerned About Dementia

No brain training program has been proven to prevent or delay dementia in rigorous, replicated research. The 29 percent risk reduction claim from ACTIVE came from secondary analyses with methodological limitations and awaits independent confirmation.

The best-supported approach to reducing dementia risk involves multiple lifestyle factors: regular physical exercise, managing cardiovascular health (blood pressure, cholesterol, blood sugar), maintaining social connections, engaging in intellectually stimulating activities throughout life, and adequate sleep. Brain training might be one component of cognitive engagement, but it's not a magic bullet and shouldn't replace these more fundamental health practices.

The Honest Conclusion

Brain training occupies an uncomfortable middle ground that doesn't make for compelling marketing copy. It's neither worthless nor transformative.

You will reliably improve at the specific tasks you practice. This is not in dispute. If you do working memory exercises, your working memory on similar tasks will get better. If you practice processing speed tasks, you'll get faster at those tasks. Near transfer is real.

But the broader claims—that brain training boosts general intelligence, prevents dementia, improves work or school performance, or enhances everyday cognitive function—are not supported by rigorous, well-controlled research. When scientists properly account for placebo effects, use active control groups, and look for transfer to meaningfully different tasks, the benefits largely disappear.

The exception is processing speed training for older adults, which shows more durable effects and possible transfer to real-world activities. This remains the best-supported brain training approach, though even here the benefits are more modest than marketing suggests and the dementia prevention claim awaits replication.

What's most striking about decades of brain training research is how consistently it reveals the domain-specificity of human cognition. We want to believe that exercising our brains works like exercising our bodies—that general cognitive fitness can be built through any mentally challenging activity. But the evidence suggests our brains are more specialized. Skills are specific, and improvement in one domain doesn't automatically transfer to others.

This doesn't mean mental engagement is unimportant. Challenging yourself intellectually throughout life, staying physically active, maintaining social connections, managing your health, and continuing to learn clearly matter for brain health and cognitive function. But these benefits likely come from the cumulative effect of living an engaged, healthy life rather than from targeted training on abstract computerized tasks.

If you choose to use brain training, choose programs with specific research support, set realistic expectations focused on the trained skills themselves, and don't neglect the fundamentals: exercise, sleep, social connection, cardiovascular health, and real-world learning. These remain the best-supported approaches for maintaining cognitive health across the lifespan.

The brain training industry sells hope for cognitive enhancement that current science cannot deliver. But the evidence can guide you toward honest expectations about what's possible. What you do with your brain matters, but no shortcut exists for building and maintaining cognitive health. The path forward involves consistency, variety, and engagement with life itself—with or without an app.