"It's the 'use it or lose it' phenomenon, with a twist," said the study's lead researcher Dr. Fredric Wolinsky. "We learned that what you are using matters. Here, the exercise designed by neuroscientists delivered significant gains that generalized to daily life, and the crosswords, which a lot of people have placed their faith in, showed no measurable benefits."

The study also broke new scientific ground in comparing older and younger users, users on their own at home against users in a supervised setting, and users spending varying amounts of time on the brain´-fitness exercise. "Some of the results pleasantly surprised us," Wolinsky said. "Others confirmed what we believed from earlier research."

The researchers separated 681 generally healthy people into four groups. One group was given computerized crossword puzzles, while the other three groups did the brain-fitness exercise in different settings – on their own at home, in a supervised setting, or in a supervised setting with four extra hours of "booster" training. Researchers also compared participants aged 50-64 against those aged 65-plus.

The game-like exercise was originally developed with funding from the National Institutes of Health and is now commercially available from the brain-fitness company Posit Science. Users train their brains by dividing their attention between a task in the center of the screen (identifying which of a pair of similar vehicles were displayed for a split second) and a task at the periphery (locating a target road sign on the periphery displayed for a split second among distractor images). As users get answers correct, the images flash for shorter and shorter periods of time, the images get more and more similar, and the objects in the periphery move further out with more distractors. The exercise is designed to simultaneously improve processing speed, attention, working memory, useful field of view, and other executive functions.

Researchers found that the exercise users showed significant gains across all these cognitive areas. When measured a year after being trained, they retained significant improvements, which were equivalent to what an average person at these ages is expected to lose in cognitive abilities over a period of nearly seven years.

To most people it is probably surprising that just ten hours of brain exercise can deliver gains that are measurable at all a year later," said Wolinsky. "You certainly would not expect that from physical exercise. Yet, here we saw gains of 1.5 to 6.6 years across the different standardized tests." Gains of that magnitude are consistent with other studies of Posit Science exercises published in scientific and medical journals, including gains of about ten years noted immediately after training.

Researchers reported that the instruments used to measure gains in the study were generally quite different than the exercise and demonstrated that the gains generalized and extended beyond the tasks trained.

"This is consistent with past studies that show our unique approach to brain exercises drive changes that generalize to daily life," said Dr. Henry Mahncke, CEO of Posit Science, the commercial distributor of the studied exercise. "Numerous studies have shown our exercises not only improve cognitive function, but that those gains translate to common daily tasks, as well as improved mood, confidence, functional independence and various measures of quality of life."

Researchers wanted to determine if more training would result in greater gains. The sub-group of participants that received an extra four hours of training posted even greater gains.

"There are now some seventy published journal articles on the multitude of benefits from training with our exercises," said Dr. Mahncke. "Once again this study confirms that more exercise is better. We recommend fitting brain exercise into your life much like physical exercise. A minimum of thirty minutes three times a week is good, and getting in more hours each week is even better."

Since most of the research on the impact of cognitive training on the aging brain has been done in populations aged 65 and older, researchers were particularly interested in whether gains would be as great in a younger population. One theory held that since older people had greater cognitive decline, they had a larger opportunity to improve than younger folks who might hit a ceiling on how much they could improve. While another theory observed that the greatest gains are made by those who make it deepest into the stimulus sets and that younger people might make it further and have greater gains.

Dr. Wolinsky noted that the researchers were somewhat surprised that there was no difference between the group aged 50-64 and the group aged 65 and older in their ability to make large gains. "This suggests that as with physical exercise, anyone can improve at any age," said Dr. Wolinsky. "And, as with physical exercise, why would you wait until you are old to get into better shape?"

Researchers were also surprised that people who did the exercises on their own at home did just as well as people who did them under supervision. This indicates that the training can be widely deployed at low cost and to remote areas.