Prof Mairéad MacSweeney
Professor of Cognitive Neuroscience
Visual Communication Group Leader
Current Research and Interests
We explore the neural basis of language processing in people who are born profoundly deaf. Our research focuses on sign language, speechreading and reading of written English. Exploring the brains of adults who have had very different sensory and language experience from the norm allows a unique perspective on how experience shapes the brain. For example, we have shown that parts of auditory cortex can be used to process visual information in people who are born deaf. Advances in this field are not only of theoretical interest, but are likely to also have important practical implications for how we educate deaf children, since the vast majority of deaf children find it very difficult to learn to read.
I explore how the brain processes language in people who are born profoundly deaf. Exploring the brains of adults who have had very different sensory and language experience from the norm allows a unique perspective on how experience shapes the brain. Working with deaf volunteers is the only way to address a number of important questions in cognitive neuroscience. For example, using fMRI we have shown that when auditory input is absent from birth, auditory parts of the brain can they be taken over to process input from other senses, such as vision. We have also shown that the brain engages very similar networks to process signed and spoken language. This suggests that the brain treats language as language, regardless of whether it comes in via the eyes or the ears. Such advances are not only of theoretical interest, but may also have important practical implications for how we educate deaf children. In my current research, funded by the Wellcome Trust, I am examining the impact of late sign language acquisition on language processing. I am testing the hypothesis that the neural circuitry recruited for language processing is dependent upon age of language acquisition and is affected by first language experience. I am also exploring the implications of altered sensory and language experience for reading and the neurobiological basis of reading. Despite normal non-verbal IQ, the average deaf child leaves school with a reading age of nine-years. I will test the hypothesis that reading can build upon a visual-spatial language. Literacy correlates with sign language proficiency; however, the sign-related skills that may facilitate this relationship are unclear. I predict this facilitation may result from: a) overlap in the neural systems supporting fingerspelling and orthographic processing and b) overlap in the neural systems recruited by sublexical processing of sign and speech.