Matthew Cohen/rd.com, Apple by Aguiardesign

You can take fish oil supplements or eat lots of turmeric. You can invest in a language class, puzzle books, or a few hours of exercise every week. There are countless methods to (allegedly) improve your memory and cognitive functioning—the brain-training and -assessment industry is expected to reach $8 billion by 2022, according to a major market research report. But the cheapest, easiest, and most time-tested way to sharpen your brain is right in front of your face. It’s called reading.

The fact that reading is good for your brain isn’t surprising—there’s a reason moms are always on their kids’ cases to turn off the TV and pick up a good book. But there’s something astounding about how such an ordinary activity can improve your brain in so many ways.

The most basic impact occurs in the area associated with language reception, the left temporal cortex. Processing written material—from the letters to the words to the sentences to the stories themselves—snaps the neurons to attention as they start the work of transmitting all that information. That happens when we process spoken language, too, but the very nature of reading encourages the brain to work harder and better. “Typically, when you read, you have more time to think,” says Maryanne Wolf, EdD, director of the UCLA Center for Dyslexia, Diverse Learners, and Social Justice. “Reading gives you a unique pause button for comprehension and insight. By and large, with oral ­language—when you watch a film or listen to a tape—you don’t press pause.”

And the benefits of reading continue long after you’ve put down that great book. A small study at Emory University found that some of those benefits persisted for five days. “We call that a shadow activity, almost like a muscle memory,” says Gregory Berns, PhD, director of the Center for Neuro­policy at Emory. In fact, this is how reading in a certain font can improve your memory.

OK, you say, it’s hardly surprising that the language part of the brain would get a workout from reading. But reading also energizes the region responsible for motor activity, the central sulcus. That’s because the brain is a very exuberant play actor. When it is reading about a physical activity, the neurons that control that activity get busy as well. You may not actually be riding a horse when you’re reading Seabiscuit, but your brain acts as if it is. And the more parts of your brain that get a workout, the better it is for your overall cognitive performance.

That said, not all reading is created equal. Preliminary results from a study conducted at Stanford University indicate that close literary reading in particular gives your brain a major workout. MRI scans of people who are deep into a Jane Austen novel showed an increase in blood flowing to areas of the brain that control both cognitive and executive function, as opposed to the more limited effects that come from more leisurely reading.

What if you are (or someone you know is) a poor, or even a dyslexic, reader who feels as if you’ll never be able to read enough to reap these benefits? A book can fix that problem too! Scientists at Carnegie Mellon University studied children ages eight to ten who were below-average readers. One hundred hours of remedial reading classes significantly improved the quality of their brains’ white matter—the tissue that carries signals between areas of gray matter, where information is 
processed. The researchers’ conclusion: The brains of these children had begun to rewire themselves in ways that could benefit the entire brain, not only the reading-centric temporal cortex. Learn more about why your brain needs to read every single day.

Matthew Cohen/rd.com, Apple by Aguiardesign

The ability to read closely is something that needs to be nurtured. In her new book, Reader, Come Home, Wolf notes that even she, as someone who reads for a living, has found her ability to concentrate on the written word fading as more of what we read is on a screen. “Unfortunately, this form of reading is rarely continuous, sustained, or concentrated,” she writes. That sets up a vicious cycle: Without the sustained exercise of our reading “muscles,” the brain loses its ability to control the intricate processes that allow us to read deeply.

Of course, there’s an easy solution: Turn off your phone and your computer, set aside a good hour or two—and just read. Not sure where to start? Pick up one of these 100 books everyone should read before they die.