Language is a uniquely human ability that evolved at some point in the six million years since humans and chimpanzees diverged. Even without being taught or having adults to copy, children develop sophisticated language systems. In contrast, reading is a skill that does not develop without intensive tuition and practice.

Since most of us learn to read as children, while at the same time building countless other skills, researches have found it nearly impossible to isolate brain structure changes related specifically to reading. In the October 14 edition of Nature, researchers describe a study with former guerrillas in Colombia who learn to read for the first time as adults. The study has helped scientists see firsthand how brain structure changes after learning to read as well as pinpoint the key regions of the brain involved in literacy.

These findings have the potential to further research into the causes reading disorders such as dyslexia. Studies of dyslexics have shown reduced grey and white matter in regions that grow after learning to read. The new study suggests that some of the differences seen in dyslexia may be a consequence of reading difficulties rather than a cause.