Reading is a skill that many of us take for granted. Of course, we aren’t born knowing how to do it. Just like learning to play a musical instrument or program a video game—it usually takes years of concentrated practice before we get really good at it. And the biology of reading is more complicated than you might think. In fact, scientists don’t yet fully understand all that is happening in your brain as you read these words. This makes it hard to figure out what’s happening in the brains of people who have dyslexia (that is, trouble deciphering, pronouncing, or reading words). Studies have shown that it takes more than visual decoding of groups of letters to understand the meanings of written words—we actually need to hear the words pronounced to really “get it.” As you read these words, think about what’s going on in your head. Do you hear a voice? When we read silently, an inner voice talks to us. It turns out that our brains process the combinations of letters we see into sounds that the inner voice pronounces. The brains of people with dyslexia have trouble recognizing letter combinations that make certain sounds, and their inner voice stumbles on pronunciation, making reading slow and difficult. But just like other learned skills, reading is easier for some people than others. And with practice, pretty much anyone can do it.   —Jenifer Lienau Thompson

Many thanks to Julie Fiez at Pitt’s Learning Research and Development Center for clearly pronouncing the details of dyslexia. For more kid-friendly science, visit the Office of Science Education Outreach, Health Sciences’ Web site, How Science Works, www.howscienceworks.pitt.edu.