Aphasia is a disorder characterised by impairment of the skill to use or understand language, and usually arises as a result of acquired brain injury such as a stroke. Ruiter’s research is motivated by the fact that people with aphasia show differences in their language skills. This is not just about the differences between individuals, but especially the differences shown by the same person with aphasia, depending on the context and tasks being performed. These differences within speakers (intra-speaker variation) are dismissed as noise by some researchers, but according to Ruiter, these differences can offer important insights into adaptive capacity. That ability is important for the extent to which communication behaviour can be adapted to still get the message across.
Ruiter explains: "We know that no two people with aphasia are the same and that even one person can show different language skills depending on the task. For example, the language behaviour of some people with aphasia is different in informal conversations compared to describing pictures. A picture description task may force them to attempt the production of more complex, complete sentences, in which language errors are likely to occur due to the aphasia. In informal conversation, they can sometimes substantially reduce the complexity of their utterances, resulting in fewer language errors.”
The first, preliminary results of the study, suggest that the degree of intrapersonal variation is not the same for every speaker. These findings could imply that greater intrapersonal variation is related to better recovery prospects, but more data is needed to confirm.
Implications for treatment of aphasia
Besides increasing our understanding of aphasia, this research has practical implications for the treatment of people with aphasia. Clinicians may better tailor programmes to maximise each patient's ability to adapt because of this research. Moreover, the research strives to improve diagnostic tools and automatic speech recognition systems used to assess language disorders, among other things. Because the data will also be made available to other researchers via the Radboud Data Repository after completion of the study, the database provides an impetus for broader scientific aphasia research in the Netherlands.
The project group consists of researchers from the CLS, DCC, MPI and Radboudumc, namely Vitória Piai, Willemijn Doedens, Henk van den Heuvel, Paul Trilsbeek, Frank-Erik de Leeuw, Anil Tuladhar and Marina Ruiter. This research is funded by the Stichting Afasie Nederland (SAN), the Centre for Language Studies and the Adaptive Language Consortium, reflecting the collaborative and interdisciplinary nature of the research.