In our youth-obsessed culture, gray hair and crow's feet command a lot of time, money and attention. But what good is a shiny racecar with a rusted-out engine under the hood? Staying mentally sharp is a top concern for our graying population — and it's big business, too.
"Brain health" companies such as Lumosity and Posit Science offer popular Web and mobile games that promise to act like a fountain of youth for your gray matter. The companies advertise that their games improve such cognitive skills as memory, attention, processing speed, mental flexibility and problem solving. And their products are selling. According to a 2013 report by independent market-research firm SharpBrains, the brain-health industry surpassed $1 billion in revenues in 2012.
But how effective are they? Psychologists have found that cognitive training can, in fact, have payoffs for skills like memory and problem solving. But scientists are still sorting out the specifics about how best to turn that training into brain games that work.
Slowing down
Cognitive decline is an unavoidable part of aging, even for those who don't experience dementia. As the years go by, you're more likely to misplace your keys or forget an acquaintance's name. Multitasking becomes increasingly difficult. Out scoring your grandkids at their favorite video game is all but impossible.
As we get older, memory loss is often a chief complaint. But it's not the first cognitive skill to decline, says Sherry Willis, PhD, a developmental psychologist at the University of Washington. As early as our 20s or 30s, we see drop-offs in perceptual speed — our ability to quickly and accurately respond to simple stimuli, such as scanning a printed text to find all the words with the letter "a." "These are simple tasks that everyone can do, but the ability to do them slows down with age," Willis says.
Many commercial brain games target this ability with the hope that processing-speed improvements will spill over into other cognitive domains, says Glenn Smith, PhD, a neuropsychologist at the Mayo Clinic and a member of the APA Committee on Aging. His research has shown that training people in one cognitive skill can lead to benefits in other areas of cognition, such as memory and attention.
Smith admits he started out as a brain-training doubter. Then about 10 years ago, a researcher from Posit Science approached him at a scientific conference. That conversation led to his designing a randomized trial to put the product to the test. Now, he says, "I'm not so much a skeptic."
Smith's study was dubbed Improvements in Memory with Plasticity-based Adaptive Cognitive Training, or IMPACT. He and his colleagues tested a computerized brain-training program in adults over 65 who did not have dementia. Over an eight-week period, participants in the training group practiced computerized exercises designed to improve the speed and accuracy of auditory information processing, while those in a control group watched educational videos. Those who completed the computerized training showed significantly greater improvements in general tests of memory and attention, even though those abilities weren't explicitly trained for (Journal of the American Geriatrics Society, 2009).
Unlike the control subjects, participants in the training group also noticed improvements in their daily lives. "Over the time course of our trial, the folks who did the computer-based training reported fewer problems in daily function that they attributed to memory change," says Smith.
Those improvements weren't permanent, however. Smith and his colleagues tested the participants again three months after the training ended and found the cognitive improvements had waned. "The processing speed benefit persisted three months out, but we saw a loss of the transfer to other cognitive domains," he says (Journal of the American Geriatrics Society, 2011).
That doesn't mean training is ineffective, though. You wouldn't expect to stay in shape if you quit going to the gym for three months, Smith points out. "Lasting effects are questionable from brief interventions, but in my opinion, persistence with cognitive exercise is likely to maintain benefits," he says.
Lasting changes
Yet other types of cognitive training do appear to stick. Some evidence for lasting effects comes from a large-scale, National Institutes of Health-funded study known as Advanced Cognitive Training for Independent and Vital Elderly, or ACTIVE. The initial trial was led by Willis, George Rebok, PhD, of Johns Hopkins University, and Karlene Ball, PhD, of the University of Alabama at Birmingham. The researchers recruited more than 2,800 older adults without dementia for a cognitive training intervention.
They randomly assigned participants to receive training on one of three cognitive skills: memory, reasoning or speed of processing. Those in the treatment groups participated in 10 hour-long training sessions over five to six weeks.
All three interventions improved the cognitive ability that was targeted, though the effects were smaller for memory training (JAMAopens in new window, 2002). By the 10-year follow up, the effects on memory had faded, says Jonathan W. King, PhD, a program officer for ACTIVE at the NIH's National Institute on Aging. In general, he says, memory interventions tend to be less effective than training that's targeted at other cognitive skills. That might be a basic problem of biology, he says. Age-related memory loss may be partly unavoidable due to reduced plasticity of brain cells as we age.
Remarkably, though, the researchers found that the ACTIVE participants who were trained in reasoning and processing speed still showed benefits in those areas a decade later (Journal of the American Geriatrics Societyopens in new window, 2014).
King expected that the reasoning benefits might persist for the long term. That's because the training taught participants to use specific strategies for problem solving — strategies that they likely used on a regular basis when tackling everyday problems over the years that followed.
But he says he was quite surprised that a few hours of training could lead to improvements in processing speed that persisted for 10 years. He suggests that once people learned to have better control over their attention and mental processing abilities, they were somehow able to apply what they'd learned in their daily lives as well. "Perhaps at some level they were still practicing that in real life, when they were just walking or driving around," King says.
It's not entirely clear, however, how much the interventions help participants in the real world.
In the ACTIVE study, participants in the training group reported fewer difficulties with the activities of daily living compared with those in a control group. Yet when researchers tried simulating everyday tasks in the lab — such as asking participants to look up a telephone number in a phone book or read a prescription label for dosing information — they fared no better than those in the control group.
But trying to recreate real-world activities accurately in a lab is problematic. "It's difficult to come up with objective, non-self-reported measures that tell us about people's level of function," King says. "We're not following them around with clipboards and stopwatches." Outside the lab, though, there are other signs that cognitive training has tangible real-world benefits. Ball gathered participants' motor vehicle records from the six years following training. Compared with those in the control group, she found, those who received training in reasoning or speed of processing had a roughly 50 percent lower rate of at-fault collisions (Journal of the American Geriatrics Societyopens in new window, 2010).
Working memory
Jason Chein, PhD, a psychologist at Temple University, also investigated the real-world effects of cognitive training. In one example, Chein and his colleagues trained neurologically healthy adults, ages 60 to 80, with a complex working memory task over four to five weeks. After training, the participants showed improvements on short-term and working memory tasks that weren't explicitly trained for. They also reported improvements in their attention outside the lab. Those in a control group, who completed trivia quizzes rather than cognitive training, reported no such improvements in attention (Psychological Aging, 2011).
For many researchers, working memory is an appealing target for training. Working memory accounts for a large extent of the variation in fluid intelligence among individuals, says Susanne Jaeggi, PhD, a cognitive neuroscientist at the University of California, Irvine. She found that computerized games designed to improve working memory also boost cognitive skills that rely on that ability, such as reading comprehension (Child Neuropsychologyopens in new window, 2012) and visuospatial skills (Developmental Psychologyopens in new window, 2014).
Yet it's hardly clear that improving working memory can boost your smarts. In Chein's 2011 study, for instance, as well as in a similar study he conducted in younger adults (Psychonomic Bulletin & Review,opens in new window 2010), participants showed no gains in fluid intelligence despite measurable improvements in working memory.
Other researchers have also expressed doubts about working-memory training. Among them is Zachary Shipstead, PhD, a psychologist who studies working memory at Arizona State University. He and colleagues including Randall Engle, PhD, a psychologist at Georgia Institute of Technology, conducted a variety of experiments designed to improve working memory. In one recent example, participants showed some improvements in their recall abilities following training, Shipstead says. But those improvements didn't translate to any measurable change in their fluid intelligence (Psychological Scienceopens in new window, 2013).
After reviewing the literature, Shipstead concluded that the evidence for improving working memory is thin (Psychological Bulletinopens in new window, 2012). He suggests that such training might simply teach people to do well on specific types of laboratory tests. "Is their memory improving, or are they just getting better at doing cognitive tasks?" he asks. "I just don't see enough consistency in the data, and I don't think these tasks are really doing much."
Efficient brains
Cognitive training may still be, as Shipstead puts it, "a work in progress." And one big remaining question is what, if anything, these products do to the brain.
"I cringe when people talk about ‘brain training' rather than ‘cognitive training,'" Willis says. " "Until more neurological work can illuminate the neural effects, we don't know what this training is doing to the brain."
Jaeggi is among those exploring the neurobiology. Using functional MRI, she's found that working-memory training appears to increase neural activity in the short term. But over the longer term, as people's cognitive skills improve, the brain regions for working memory actually show less activity when being called to action (Developmental Cognitive Neuroscience, 2012). In other words, the well-trained brain seems not to have to work as hard. "The neurons are better wired together, in a sense, and are more efficient," she says. "That might help you do better in other tasks that rely on the same neural networks."
Jaeggi is also exploring who stands to gain the most from cognitive training. In her research, she says, children and older adults typically show the most improvement. But that may be because healthy young adults are already functioning near peak mental performance. "Maybe we don't have sensitive enough measurement tools to see what's really going on," she says.
Initially, researchers suspected that brain training might be a case of making "the rich richer," says Jaeggi — that the interventions would work best for those who already functioned at a high cognitive level. But the opposite now appears to be true. "We typically see the largest improvement in those who start at the lowest level," she says (Memory & Cognitionopens in new window, 2014).
That's encouraging, since it suggests that people who most need a cognitive boost are the ones likely to benefit from training.
Despite lingering questions, companies are pushing ahead with brain-training products. Some of those programs have science behind them, says Willis. The perceptual speed training that was used in the ACTIVE study, for instance, is now part of Posit Science's package.
But many other brain games on the market haven't been tested under controlled conditions. "I don't want to say they're not helpful, but we just don't have the strong research to back up the claims. And for the most part, the companies haven't done much follow-up research, so we have no idea if the effects are maintained," Willis says.
Some critics have questioned whether the games are any better than other cognitive pursuits, such as learning a new language or playing a musical instrument. In a recent meta-analysis, Shoshana B. Hindin and Elizabeth M. Zelinski, PhD, at the University of Southern California, found that extended cognitive training improved cognitive performance about as much as regular aerobic exercise, suggesting that brain games aren't the only way to keep your mind sharp (Journal of the American Geriatrics Societyopens in new window, 2012).
Then again, one nice feature about computerized brain games is that they're adaptive — as players get better at a task, the games adjust to become more challenging. Yet again, there's a clear analogy to physical exercise. While some people are motivated to lift ever-heavier weights or run faster on their own, others need a trainer to push them. Cognitive training is no different, says Willis. "Some people are just more inclined to be persistent. Others need somebody to keep them on task."
Though commercial brain-training programs are designed to be entertaining, they shouldn't be all fun and games. "Games that are actually helpful are effortful. It's not enough to sign up for Lumosity and think you'll get somewhere, just like you can't buy yourself a gym membership and expect to lose weight," Jaeggi says. "You have to actually do the training."
Kirsten Weir is a journalist in Minneapolis.
