Thursday, September 18, 2014

Amblyopia In Early Childhood May Alter Speech Perception

The presence of amblyopia during early childhood may lead to impaired visual-auditory speech integration and alterations in speech perception, according to a study published online September 11 in JAMA Ophthalmology.

"Among human children, in the past, we only knew that amblyopia affected visual acuity and stereopsis (ability to see in [3 dimensions]). Now, our research shows that amblyopia affects an entirely different sensory system: our perception of sound," lead author Rajen U. Desai, MD, from the Feinberg School of Medicine at Northwestern University, Chicago, Illinois, told Medscape Medical News.

Speech recognition includes not only auditory processing but also processing of visual cues from the speaker's mouth and face. The authors test this concept using the McGurk effect. "[W]hen presented with an audio track playing /pa/ and a separate video track of a person silently articulating /ka/, participants will most often claim to hear a unique fusion sound /ta/." Approximately 85 to 90% of individuals with normal auditory and visual processing will report hearing the fusion sound, they note.

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When asked how this information may be applied clinically by pediatricians to improve integration among patients who have delayed resolution of their amblyopia, Dr. Desai responded: "For amblyopia that was corrected too late, pediatricians and parents can consider asking the children to listen to them only using their 'good' eye (and to close their amblyopic eye). A few of our study patients heard completely different sounds depending on which eye they were using to look at someone talking to them. They heard the correct sound when they closed their amblyopic eye."
When asked how this information may be applied clinically by pediatricians to improve integration among patients who have delayed resolution of their amblyopia, Dr. Desai responded: "For amblyopia that was corrected too late, pediatricians and parents can consider asking the children to listen to them only using their 'good' eye (and to close their amblyopic eye). A few of our study patients heard completely different sounds depending on which eye they were using to look at someone talking to them. They heard the correct sound when they closed their amblyopic eye."


http://www.medscape.com/viewarticle/831686