The Surprising Type of "Noise" That Makes It Tough to Read

As many as 18% of people have a devil of a time learning to read, a disorder known as developmental dyslexia, and often their reading problems persist into adulthood. Various theories attempt to explain the processing glitch that occurs in the minds of dyslexic individuals. Recently I read a new study that made an intriguing contribution to our understanding of this confounding disorder.

It had to do with what researchers called noise, but not the kind of noise that comes from having a radio blaring or friends chitchatting in the same room where someone's trying to read. Rather, the researchers looked at "visual noise" -distracting images that appeared along with, but had no relevance to, the target information. In this study, the visual noise consisted of a checkerboard pattern that appeared on the computer screen while the study participants were engaged in various reading-related tasks.

What they found: Everyone did worse when the tasks included the visual noise -but such distractions interfered far more with the performance of dyslexic participants than with nonimpaired readers. When the distracting checkerboard was replaced with a plain gray background, however, the test scores of the dyslexic readers were essentially the same as those of the normal readers. Explanation: For dyslexics, the inability to effectively filter out irrelevant information leads to poor categorization of letters and other reading problems, researchers said.

So the question is: Given that visual background noise is especially distracting for dyslexics, I wondered whether people with dyslexia would have better success with texts that had extraneous stuff stripped out. For instance, might it be easier for dyslexics to comprehend the "printer-friendly" versions of web pages, from which advertisements, large photos, and other visual extras have been removed? Maybe. But the study's lead author, Rachel L. Beattie, PhD, told me that a better approach would be to train dyslexic individuals to read in the presence of visual noise (in addition to normal "no-noise" treatments), thus enabling them to develop better strategies for success when faced with the need to read when irrelevant distracting information is present. More info: The International Dyslexia Association (www.InterDys.org).

Colorful wishes,
Helen

Rachel L. Beattie, PhD,is a lecturer at the University of Southern California and an adjunct assistant professor at Occidental College, both in Los Angeles. She is the lead author of a study on dyslexia and visual noise published in PLoS ONE, a peer-reviewed journal from the Public Library of Science.