Though learning to read proceeds smoothly for most children, as many as one in 10 is estimated to suffer from dyslexia, a constellation of impairments unrelated to intelligence, hearing or vision that make learning to read a struggle. Now, Northwestern University researchers report they have found a biological mechanism that appears to play an important role in the reading process.
“We discovered a systematic relationship between reading ability and the consistency with which the brain encodes sounds,” says Nina Kraus, Hugh Knowles Professor of Neurobiology, Physiology and Communication. “Unstable Representation of Sound: A Biological Marker of Dyslexia,” co-authored by Jane Hornickel, will appear in the Feb. 20 issue of The Journal of Neuroscience.
Recording the automatic brain wave responses of 100 school-aged children to speech sounds, the Northwestern researchers found that the very best readers encoded the sound most consistently while the poorest readers encoded it with the greatest inconsistency. Presumably, the brain’s response to sound stabilizes when children learn to successfully connect sounds with their meanings.
Happily biology is not destiny. In prior work in Northwestern’s Auditory Neuroscience Laboratory, Kraus and her colleagues found that the inconsistency with which the poorest readers encode sound could be “fixed” through training.