News Release

Johns Hopkins finds training exercise that boosts brain power

Peer-Reviewed Publication

Johns Hopkins University

Brain Training Graphic

image: EEGs taken before and after the training showed that the biggest changes occurred in the brains of the group that trained using the "dual n-back" method. view more 

Credit: Kara J. Blacker/JHU



"People say cognitive training either works or doesn't work. We showed that it matters what kind of training you're doing," said lead author Kara J. Blacker, a former Johns Hopkins post-doctoral fellow in psychological and brain sciences. "This one task seems to show the most consistent results and the most impact on performance and should be the one we focus on if we're interested in improving cognition through training."

Scientists trying to determine if brain exercises improve cognitive performance have had mixed luck. Johns Hopkins researchers suspected the problem wasn't the idea of brain training, but the type of exercise researchers chose to test it. They decided to compare directly the leading types of exercises and measure people's brain activity before and after training; that had never been attempted before, according to Blacker, now a researcher at the Henry M. Jackson Foundation for Advancement of Military Medicine Inc.





The "dual n-back" is a memory sequence test in which people must remember a constantly updating sequence of visual and auditory stimuli. The Johns Hopkins participants saw squares flashing on a grid while hearing letters. They had to remember if the square they just saw and the letter they heard were both the same as one round back. As the test got harder, they had to recall squares and letters two, three, and four rounds back. It's a bit like the children's electronic game Simon, but instead of just recalling sounds and colors, you have to remember the current sequence and the one a few rounds back.

The other test, called "complex span," also involves remembering items in a sequence. There's a distraction for people between items, but they don't need to continually update the items in their mind.

The findings demonstrate that the "dual n-back" is a better regimen to train working memory, which is what people rely on to temporarily hold details in their mind like phone numbers and directions. These skills are vital to how people perform in school and at work, when tasks are new and you can't just rely on old knowledge and habits, says co-author Susan Courtney, a Johns Hopkins neuroscientist and professor of psychological and brain sciences.

"The findings suggest that this particular task is changing something about the brain," Courtney said. "There's something about sequencing and updating that really taps into the things that only the pre-frontal cortex can do, the real-world problem-solving tasks."

The next step, the researchers say, is to figure out why "dual n-back" is so good at improving working memory, and then figure out how to make it even more effective so that it can become a marketable, or even clinically useful, brain training program.

"The biggest lesson here was that - yes - intensive training strengthens cognition and the brain, but we still don't understand why and how," Courtney said. "We can't just jump onto a video game and expect that's going to cure all of our cognitive problems. We need more targeted interventions."


Note: Related video here

Co-authors included Serban Negoita, a former Johns Hopkins student who's now a Johns Hopkins Medicine research program coordinator, and Joshua B. Ewen, a neurologist with Johns Hopkins and the Kennedy Krieger Institute.

This project was supported by a Johns Hopkins University Science of Learning grant and by National Institutes of Health grants R01 MH082957 and K23 NS073626.
