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 People have thoughts on Charlie Kirk and are getting fired for them. Charlie Kirk's widow has a message for the world. Utah's governor asks a tough question after Kirk shooting. Not so fast on scanning that QR code. Report an error