Research Projects

Approximately 15 million people suffer a stroke every year worldwide. Stroke is the second leading cause of long-term disability, following ischemic heart disease, in developing countries (Feigin et al. 2017). Around one-third of stroke survivors are diagnosed with Aphasia: An acquired disability to produce and comprehend language. An individual with Aphasia may exhibit a range of language deficits, including word-finding difficulty, disfluent and effortful speech, grammatical errors, fluent but nonsensical speech, difficulty in comprehension, and difficulty with reading and writing. Aphasia severely impairs the quality of life and delays the rehabilitation for stroke patients. Rehabilitation of patients with aphasia faces two major challenges. First, there is a scarcity of standardized diagnosis tools in low-resource languages, like Hindi and Telugu (Pauranik et al. 2019). Diagnosis of Aphasia requires a standardized battery of language performance tests in the patient's native language to evaluate the severity and type of Aphasia. Developing such a diagnosis battery demands large-scale experimental research on language production and comprehension tasks in individuals with Aphasia (IWAs) and healthy controls. Second, there is considerably limited research on the efficacy of different therapeutic interventions used in treating Aphasia (Friedriksson el al. 2022). Moreover, the efficacy of these interventions can significantly differ across languages due to different typological and morphological properties. Substantial empirical and computational modeling research is required to determine which treatment methods are effective for a certain type of Aphasia and exactly why they are effective. The alarming incidence rate of stroke patients in India (approx. 300 per 100,000/year) makes Aphasia one of the most common long-term disability that severely impairs individuals' quality of life. Around 2 million people in India are affected by Aphasia (Pauranik et al. 2019). It is critical that Aphasia is properly diagnosed in the Indian population and effective treatment options are available. The proposed project aims to develop diagnosis and treatment tools for Aphasia in Indian languages. To this end, we plan to launch a dedicated research programme for extensive experimental and computational research on Aphasia in Indian languages and develop tools for proper diagnosis and individualized therapeutic interventions. We propose to implement this project in four phases - (i) Theoretical inferences from existing data: We plan to do a meta-analysis of existing data on Aphasia in Indian languages to develop a theoretical understanding of language deficits in Aphasia with regards to Indian languages; (ii) Experimental research to identify markers of language deficits and efficacy of different interventions: We plan to do large-scale, controlled psycholinguistic experiments on individuals with Aphasia and controls to assess the nature of language deficits in case of Indian languages (for diagnostic tools) and to quantify the efficacy of different intervention methods (for treatment tools); (iii) Computational models of impaired and unimpaired language processing: We plan to develop and evaluate unified computational models that can predict language processing behavior in Individuals with Aphasia as well as controls; (iv) Development of diagnostic and treatment tools: Using insights from the first three phases, the final phase will focus on developing a standardized battery of diagnostic tests and treatment protocol for individualized therapeutic interventions in Indian languages. The above four phases together make a pipeline of treatment and rehabilitation of Individuals with Aphasia in the Indian language population. During next three years, we plan to implement this research and development pipeline for Hindi, an Indian language spoken by over 500 million people.