Most of us strive to sharpen our mental agility by doing Sudoku, exercising, and getting a good night's rest. In addition, popular computer-based cognitive programs and brain games are inundated with claims of rejuvenating our memory and sharpening our focus — but do they really work?

A study presented at the Alzheimer's Association International Conference (AAIC) in Toronto, Canada, found a specific type of computerized brain training game can reduce the risk of dementia by half via strengthening neural connections and boosting the speed of mental processing.

Researchers from the Wisconsin Alzheimer's Disease Research Center and Wisconsin Alzheimer's Institute sought to compare the effects of three forms of brain training in a group of over 2,800 cognitively healthy seniors with an average age of 74 in a 10-year span for the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study. The participants were sorted into four groups, including a control group, which received no brain training. One group got a classroom-based course aimed to boost memory; one group got a classroom-based course designed to sharpen their’ reasoning skills; and another group was given computerized training designed to boost the speed of mental processing. The three experiment groups received a total of 10 hours of training in the first five weeks, and around half of each experimental group got an additional training after 11 months and 35 months.

Over the 10-year follow-up period, those who got the commercially available brain training exercises had a 33 percent less risk of developing the neurodegenerative disease over 10 years than those who got no brain training at all. Among those who got a refresher class 11 and 35 months after the initial training, the risk went down even more. Those who went through more than 10 of the brain training sessions were 48 percent less likely over 10 years to experience dementia or cognitive decline.

Moreover, participants who took part in the other two training programs, which focused on memory retention and reasoning, were slightly less likely than the control group to suffer cognitive decline or dementia. This was especially true for those who got 10 sessions to improve reasoning strategies.

The computerized brain training exercise is commercially available as the “Double Decision” game, one of a suite of cognitive exercises marketed online by the San Francisco-based Posit Science Corp. The game exercises an individual’s ability to detect, remember and respond to cues that appear and disappear quickly in varying locations on a computer screen. It uses colorful graphics and challenges players with escalating difficulty as their proficiency increases.

“We believe this is the first time a cognitive training intervention has been shown to protect against cognitive impairment or dementia in a large, randomized, controlled trial,” said Jerri Edwards, first author of the study and an associate professor at the University of South Florida, in the press release.

The researchers emphasize these results are by no means a validation for brain training as a whole, but for just one specific task — boosting mental processing. Previous claims of brain training programs have included the ability to increase IQ, enhancing education, and improving daily functioning.

It's not clear why speed mental processing training works, or the exact changes it causes to the brain. However, scientists suspect continually using our brain in a certain way can actually enhance the communication between brain cells, providing a benefit in the long run. It's a cognitive skill that declines with age, and one that some researchers say contributes to the increase in “noise” in electrical communications between cells and among regions in the brain.

Edwards’ study is the first to suggest computerized brain training could potentially help against dementia. This is a crucial finding since many scientists have been skeptical of the brain training industry. For example, in a 2014 consensus statement, 70 scientists criticized brain training computerized games stating:

“We object to the claim that brain games offer consumers a scientifically grounded avenue to reduce or reverse cognitive decline when there is no compelling scientific evidence to date that they do.

Study: Edwards J et al. Brain Training May Protect Against Cognitive Impairment and Dementia: the ACTIVE Study.  AAIC 2016 Toronto, Canada.