- Children who are blind can see neither words in print nor the objects that the words refer to, such as a tree, car or a cloud.
How does this impact their vocabulary development, which begins as auditory only?
Finding that answer — something NIU professors Lindsay Harris and Allison Gladfelter are pursuing with funding from the National Institutes of Health’s National Eye Institute — could yield better services and futures for students with visual disabilities.
“A lot of reading skill depends on language ability and basic semantic knowledge, and we have very little understanding of what sort of semantic representations people who don’t have visual experiences have of the world,” said Harris, associate professor of educational psychology.
“This is going to lead to greater representation of people with disabilities in the literature on reading and language development,” she added. “There are currently limited resources for this population, and the teachers, parents and other stakeholders who want to help have very few places to turn.”
Gladfelter, associate professor of speech-language pathology, shares that sentiment.
“I have been shocked by just how little research attention has been given to children with low vision,” she said, “and how our theoretical understanding of vision’s role in language learning and reading stands to gain by including more of these children.”
Harris and Gladfelter are collecting data from 100 children ages 5 to 14 within that special population and from 100 of their typically sighted peers.
“Ultimately,” Harris said, “we want to know if the number of words a typical 7-year-old kid who is blind can identify or define is more or less the same as typically sighted kids, and there are theoretical reasons to expect either of those possibilities.”
“Why? If you don’t have vision, then you’ve spent your whole life relying on and closely attending to linguistic information to make sense of the world. They may have an advantage in developing a vocabulary.”
The nationwide, first-of-its-kind study will assess if language knowledge and use differ between blind and sighted children.
Researchers are also quizzing participants with age-appropriate words and multiple-choice definitions.
Those who answer correctly are asked to explain how they acquired that knowledge — whether from linguistic context or direct experience, and whether from speech or reading because of their reduced access to print — and their confidence that they are right.
“In the past, all studies of age of vocabulary acquisition presented visual options to kids,” Harris said, “and, even for a sighted kid who has a reading disability, you’re not going to get an accurate picture of their vocabulary knowledge because you’re asking them to read, which is hard for them.”
Researchers also hope to better understand the source of reading delays in children who are blind.
Poor vocabulary? Underdeveloped semantic representations? The difficulty of Braille? Quality of literacy instruction? If preterm birth caused blindness, is it also responsible for the delays? A combination?
“There is very little research into why that may be, and I can think of a lot of possible explanations, but not many have been tested,” Harris said.
“One possibility is that the children just don’t have the vocabulary or the word knowledge to comprehend what they’re reading,” she added. “This research will help clarify that and, ultimately, improve reading development in kids with visual impairments so, if we recognize they have a vocabulary deficit, it can be targeted in interventions or classroom instruction to help.”
Following the study’s conclusion in 2028, teachers, speech pathologists and school psychologists will have improved data to guide them.
“Assessments are going to be informed by science,” Harris said. “Teachers will know what they need to create vocabu-lary lessons or reading instructions instead of just guessing.”
Diverse expertise from various disciplines is already proving beneficial.
“Our research team includes speech-language pathology, educational psychology and special education with an emphasis on teaching students with visual impairments,” Gladfelter said. “Our external advisory board includes teachers for students with low vision, blindness, publishers of Braille texts, advocates, parents and other reading scientists. Learning how these unique perspectives contribute to the project has been fascinating.”
Gladfelter is grateful to partner with Harris, crediting NIU’s Center for the Interdisciplinary Study of Language and Literacy for fostering the opportunity.
“One of CISLL’s goals is to support interdisciplinary collaborations to study language and literacy, and I otherwise would not have come across Lindsay’s research or met her as a researcher,” Gladfelter said. “We discovered that we have really complementary research interests, and now we get to put those interests into a much larger project than either of us would have taken on independently.”
Meet the Research Team
Molly Pasley, M.S. ’09, assistant professor in the Visual Disabilities program of the NIU Department of Special and Early Education.
Brad Blair, NIU graduate research assistant and assistive technology instructor and Orientation and Mobility specialist at the Star Center in Tennessee.
Tremaine Love, NIU graduate research assistant and music teacher at Homewood-Flossmoor High School.
Rebecca Treiman, professor emeritus of Psychological and Brain Sciences at Washington University in St. Louis, who is serving as an external consultant.