Spotlight Research: Multiple Demand Study
BU Researchers Study: Functional Reorganization of the Language and Domain-general Multiple Demand Systems in Aphasia
Introduction
Our recent project on neuroplasticity and neurorecovery of aphasia examines how the brain adapts to recover language abilities in individuals with aphasia. It observes English speakers, whether they have a history of stroke or not, by studying the relationship between language and other cognitive abilities such as math and spatial processing, in terms of as the reorganization of the language system after a stroke. The study investigates potential changes in the functional architecture of the language networks in the brain and other regions not typically involved in language processing (called multiple demand regions). By expanding our understanding of language recovery beyond traditional language regions, this research could have significant implications for brain plasticity and rehabilitation, highlighting that recovery is not limited to language-specific areas. Aphasia profoundly affects quality of life, even more than cancer or Alzheimer’s disease, making this study vital for improving patient outcomes.
The Study
In order to understand the adaptations of brains with post-stroke aphasia, the study utilizes a comprehensive assessment of language and cognitive abilities through video conferencing assessment and in person brain scanning (MRI). While the current belief suggests that language recovery relies on regions of the fronto-temporal network, specifically the ipsilesional left-hemisphere or the corresponding right-hemisphere regions, this research explores a novel hypothesis that a domain-general fronto-parietal multiple demand (MD) network may also play a role in mediating language recovery in patients with aphasia (PWA). Researchers specifically evaluate three possible changes in the functional architecture of the MD and language networks: (i) the response magnitude within each network during language processing, (ii) the synchronization within the MD regions and language regions, and (iii) the synchronization between the MD and language regions across the networks. Through these areas of research, the project aims to establish a comprehensive understanding of the mechanisms underlying neuroplasticity and reorganization of language function in aphasia. Additionally, researchers are working to identify neural phenotypes that can explain the variability in linguistic and cognitive performance among PWA while accounting for differences in anatomy-function mapping. Lastly, this research’s objective is to lay the foundation for innovative behavioral and neuro-stimulation therapies that leverage the engagement of the domain-general multiple demand network to facilitate language recovery.
Significance of Research
Researchers Anne Billot and Maria Varkanitsa emphasized the importance of this research, stating that, “Aphasia has a greater negative impact on factors of preference-based health-related quality of life (HRQL) than even cancer or Alzheimer disease. However, our current understanding of the cognitive mechanisms and underlying brain systems involved in language recovery remains limited.” Understanding how impactful aphasia is on a person’s life makes it all the more important that researchers are working to find more ways to aid the brain in recovery. Billot and Varkanista also explained how this project is working to achieve this, “This study aims to broaden the investigation of language recovery beyond traditional language regions and explore the involvement of the domain-general multiple demand network. Establishing the potential recruitment of this network in facilitating language recovery will have important implications providing some insights into how the brain can sustain language recovery by reorganizing function.” The team is already making great strides in their research, and thanks to the development and resources of the Aphasia Lab and Center for Brain Recovery at Boston University they are able to make this research possible.