Reading presents a significant challenge for individuals who are born deaf because they cannot hear the language that is encoded by print. The factors that lead to skilled reading for deaf individuals are currently under debate and not well understood. This project uses behavioral, neurophysiological, and neuroimaging measures to identify what factors predict variations in the brain’s response when deaf adults read and recognize written words (e.g., spelling ability, phonological awareness, signing ability, reading speed).
The brain bases of reading in deaf adults
These studies are designed to examine brain functions during reading for deaf people who are bilingual in English and American Sign Language and to understand how the brain systems that support reading are shaped by deafness, e.g., by the changes in visual attention and phonological abilities that result from congenital hearing loss. We use both functional magnetic resonance imaging (fMRI) and electrophysiological measures (EEG/ERP) to investigate neural systems that support reading, fingerspelling, and signing in deaf individuals. We are addressing the following questions:
- What is the neural-behavioral signature for highly skilled deaf readers?
- Does deafness impact the neural response to visually presented words?
- Can we de-couple effects of deafness from effects of low literacy on reading behavior?
- Does fingerspelling engage the Visual Word Form Area?
- How does knowledge of ASL impact word reading?
Eyetracking studies of deaf readers
Eye movements provide very good clues to how people read words and text. Our lab is now equipped with an Eyelink 1000+ (from SR-Research) eyetracking system which will allow us to determine with great precision where the eyes move when comprehending written text or when viewing sign language. Using this technology, we can ask the following questions:
- Do deaf and/or hearing signers activate ASL when they read English text?
- Do young deaf readers have a wider perceptual span (region of effective vision) during reading, relative to young hearing readers?
- Which visual and linguistic processes do skilled deaf readers use during written word processing?
- Do native signers (hearing or deaf) activate English when they process sign language?
Recent work with adult and young deaf readers show that skilled deaf readers’ eye movements when they read simple sentences are very different that those of hearing readers of comparable reading skills. Deaf readers are more efficient when they read sentences compared to hearing readers with equal comprehension levels. For example, skilled deaf readers make fewer fixations in a sentence. This means that each time their eyes land on a word (called a “fixation”), skilled deaf readers are able to grab more information within that fixation. Skilled deaf readers also go back in the text (reread) less often than hearing readers do. This shows that even if deaf readers make fewer fixations than hearing readers do, they also do not need to go back in the text as often as their hearing counterpart to check their comprehension. In other words, they are “efficient” readers. Some of our upcoming projects will investigate why we find these unique and efficient eye movements in deaf readers.
This project is funded by the National Science Foundation Linguistic Programs (BCS 1154313) and Cognitive Neuroscience Program (BCS 1439257), and National Institute of Deafness and Other Communication Disorders (R01 DC 014246)
- Emmorey, K., McCullough, S., & Weisberg, J. (2015). Neural correlates of fingerspelling, text, and sign processing in deaf ASL-English bilinguals. Language, Cognition, and Neuroscience, 30(6), 749-767. Click to request PDF
- Emmorey, K., Weisberg, J., McCullough, S., & Petrich, J. A. F. (2013). Mapping the reading circuitry for skilled deaf readers: An fMRI study of semantic and phonological processing. Brain and Language, 126, 169-180. Click to request PDF
- Emmorey, K., & Petrich, J. (2012). Processing orthographic structure: Associations between print and fingerspelling. Journal of Deaf Studies and Deaf Education, 17(2), 194-204.
See recent publication by Nathalie N. Bélanger (formerly at UCSD) and Keith Rayner on deaf readers’ eye movements:
- Bélanger, N.N. & Rayner, K. (2015). What Eye Movements Reveal about Deaf Readers. Current Directions in Psychological Science, Vol. 24(3) 220-226. Click to request PDF
- Yan, M., Pan, J., Bélanger, N.N. & Shu, H. (2015). Chinese Deaf Readers Have Early Access to Parafoveal Semantics. Journal of Experimental Psychology: Learning, Memory, and Cognition, 41(1), 254-261.
- Bélanger, N.N., & Rayner, K. (2013). Frequency and predictability effects in eye fixations for skilled and less-skilled deaf readers. Visual Cognition, 21(4), 477-497.
- Bélanger, N.N., Mayberry, R. I. & Rayner, K. (2013). Orthographic and phonological preview benefits: Parafoveal processing in skilled and less-skilled deaf readers. Quarterly Journal of Experimental Psychology, 66(11), 2237-2252.
- Bélanger, N.N., Slattery, T.J., Mayberry, R.I. & Rayner K. (2012). Skilled deaf readers have an enhanced perceptual span in reading. Psychological Science, 23(7), 816-823.
- Mehravari, S., Klarman, L., Emmorey, K., & Osterhout, L. (2014). Brain-based individual difference measures of reading skill in deaf adults. Poster presented at the Society for the Neurobiology of Language, August, Amsterdam, The Netherlands. (pdf)
- Emmorey, K., Midgley, K., Grainger, J., & Holcomb, P. (2014). The temporal dynamics of visual word perception in deaf adults. Poster presented at the Society for the Neurobiology of Language, August, Amsterdam, The Netherlands. (pdf)