Researchers have long noted that dyslexic readers use eye movements that are significantly different from non-dyslexics. Although these movements have been studied in the past in small samples, a new article written by researchers at Concordia and published in the journal Nature Scientific reports look at a much larger group. The study used eye-tracking technology to record movements and concluded that people with dyslexia have a profoundly different and much more difficult way of sampling visual information than normal readers.
“People have known for a long time that people with dyslexia have slower reading rates,” says article co-author Aaron Johnson, associate professor and chair of the psychology department.
“Previous studies have also looked at eye movements in adult dyslexics. But this article brings them together quite well and uses behavioral measures to give us a full picture of the differences that occur.”
The eyes have it
Dyslexia researchers use several parameters to measure eye movements. These include fixtures (the length of a stop), jerks (the lengths of a jump), and counting the number of times a reader’s eyes express a jump. Traditionally, dyslexia researchers have used a single sentence to measure these movements. Johnson and his co-authors instead used standardized identical multi-sentence texts that were read by 35 undergraduates diagnosed with dyslexia and 38 others in a control group.
The researchers wanted to address a central question in the field: are reading difficulties the result of a cognitive or neurological origin or of eye movements that guide the taking of information during reading?
“We saw that there was a real spectrum of reading speed, with speeds in dyslexic students as low as a third of the speed of the fastest readers in the control group,” says the lead author. Léon Franzen, former postdoctoral fellow at Horizon. Fellow at the Center for Sensory Studies of Concordia now at the University of Lübeck in Germany.
“But using a variety of metrics to build a complete profile, we found that the speed difference was not the result of longer processing times for non-linguistic visual information. It suggested there was a direct link. with eye movements. “
Franzen notes that when dyslexic participants read a text, they take a longer pause to grasp the information, but they did not have difficulty integrating the meanings of the words into the context of a sentence. This behavior is often observed in children who are learning to read. Adults who read at normal speeds do not have these pauses and eye movements.
“Dyslexia is a developmental disorder that begins in childhood,” says Zoey Stark (MA 21), second author of the study. The Concordia student has just completed her Masters in Psychology and will soon be working towards a PhD where she will continue her studies in dyslexia. “It often goes undiagnosed until the child experiences real difficulty.”
The three researchers worked together at the Concordia Vision Lab.
Borrow business tools
Franzen compares the use of eye-tracking technology to the ability to scrutinize the cognitive process: researchers can see how people with dyslexia approach reading and where and how they struggle. And as eye-tracking technology becomes more mainstream and affordable – most web cameras and smartphones already have it, for example – researchers hope they can harness it to help them track and intervene in reading. dyslexic people.
“Now that we know that there are these differences in the way dyslexics read, we need to ask ourselves what we can do to improve their reading,” Johnson says. “Are there ways to modify the texts to make them easier to process, like changing the fonts or increasing the size of the text? This is the next step in our research.”
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Material provided by Concordia University. Original written by Patrick Lejtenyi. Note: Content can be changed for style and length.