Health | n-back exercises Get Smarter in 20 Days N-back exercises improve 'fluid intelligence': Study By Sarah Whitmire Posted Jun 4, 2011 1:58 PM CDT Copied 'N-back exercises' might get this in shape. (Shutterstock) Some of this week's news was enough to turn your brain to mush, but a university psychologist has a way to get it back in under three weeks. His technique involves something called "n-back exercises," a type of mental training that tests your short-term memory of symbols or noises. Doing them 20 minutes a day for 20 days improves "fluid intelligence"—the ability to reason and solve problems—for up to three months, says his University of Michigan study. (Here’s an app we found free for Android, or this one is a desktop app.) More on the medical specifics here. Read These Next NC mom missing for 24 years doesn't want to be found. BBC apologizes after racial slur heard at BAFTAs. Jack Smith's report won't ever see the light of day. FBI chief Kash Patel showed up in the Team USA hockey locker room. Report an error