Principal Investigators: Mairéad MacSweeney (UCL), Eva Gutierrez (UCL) and Chloë Marshall (UCL-IOE)
Funder: IOE/UCL Strategic Partnership Research Innovation Fund
Project description: A ‘semantic fluency task’ requires participants to produce as many words as they can from a specific category (e.g., animals) in a limited period of time. This task has a basic science function in that it indexes the organisation of words in an individual’s semantic network. The task also has an applied function, in the diagnosis of neurological disorders, and is being increasingly used in educational contexts, for example, as part of a battery of tests for the diagnosis of dyslexia.
This project investigates semantic fluency in a group who have not previously been investigated: hearing bimodal bilingual adults. These individuals were born to Deaf parents, from whom they learnt British Sign Language (BSL), and they also grew up learning the surrounding spoken language, English. This unique group of people, termed CODAs (Children of Deaf Adults), will allow us to investigate the impact of knowing a sign language (BSL) on the organisation of the spoken lexicon. We will use the semantic fluency task to investigate their semantic organisation at a behavioural level, in terms of the pattern and number of participants’ responses. We will also measure hemispheric lateralisation during performance of the task using functional transcranial Doppler sonography (fTCD).
The study will provide unique information about how the brain deals with two languages – which in this case are delivered in different modalities. Our primary hypothesis is that knowing a sign language will influence word generation in English, and that this will be reflected in the behavioural and neuroimaging data.