Dyslexia is a learning disability that affects up to 17.5 percent of the population. Although researchers believe the disorder is caused by a defect in the brain’s processing of graphic symbols, the exact cause for the condition is unknown.
Now, new research suggests the symptoms of dyslexia, including difficulties in reading, are at least partly due to difficulty filtering out excess background information like noise.
University of Southern California researchers studied 37 undergraduate students, the researchers, and found that the poor readers performed significantly worse than the control group only when there were high levels of background noise.
The two groups performed comparably at the prescribed task when there was no background noise and when the stimulus set size was varied, either a large or a small set size.
According to Rachel Beattie, Ph.D., “these findings support a relatively new theory, namely that dyslexic individuals do not completely filter out irrelevant information when attending to letters and sounds.
“This external noise exclusion deficit could lead to the creation of inaccurate representations of words and phonemes and ultimately, to the characteristic reading and phonological awareness impairments observed in dyslexia.”
The study is published in the online journal PLoS ONE.
Source: Public Library of Science