More than one million Americans have aphasia, and most of them experience some difficulty with sentence comprehension. These impairments may limit the ability to fully participate in everyday activities such as conversations and reading. Whereas considerable knowledge has been gained regarding how syntactic structure affects sentence comprehension in people with aphasia, a full understanding of the underlying deficit remains elusive. As a result, the best approaches for evaluation and treatment of sentence comprehension disorders remain unknown. This proposal draws on theories of unimpaired sentence processing to formulate new questions about the variables that make sentences difficult for people with aphasia to understand. The proposed experiments use measures of real-time sentence processing to test the hypotheses that (1) impairments affecting how quickly people with aphasia access words contribute to sentence comprehension disorders and (2) performance on measures of spoken and written sentence comprehension in people with aphasia will be similar unless there are experimental manipulations that have different effects on spoken and written word access. To test these hypotheses, two methods that are commonly used to study real-time written sentence processing in unimpaired populations, self-paced reading and eye-tracking during reading, will be extended to the study of sentence comprehension impairments in aphasia. Performance of two groups, people with aphasia and healthy age- and education- matched controls, will be compared on the two measures of real-time written sentence processing and on self-paced listening, a method that is sensitive to real-time auditory sentence processing. At present, the candidate is proficient in group studies of auditory sentence comprehension impairments in people with aphasia. However, she requires additional career development training to deepen her content knowledge of written language and lexical processing, and to develop expertise in the methods involved in using eye-tracking to study reading, and acquisition and analysis of structural MRI data. The University of Arizona has an exceptionally strong research tradition in neurogenic communication disorders (including the study of aphasia), as well as psycholinguistic studies of word and sentence processing. Neuroimaging research and lesion analysis is also highly developed at the University of Arizona, thus making it an ideal setting for the targeted skill development and conduct of the proposed research. The training opportunities will help the candidate launch a product-ive and independent research program that aims to understand the underlying nature of sentence comprehension disorders in aphasia in order to develop more effective methods for the evaluation and treatment of these impairments.
/Relevance Aphasia is an acquired language disorder that affects one million people in the United States (NIDCD). The proposed research focuses on disorders of sentence comprehension in people with aphasia. Sensitive tests reveal that even people with mild aphasia, who appear to have good comprehension, frequently have deficits affecting the speed and accuracy of sentence processing. As a result, they may not fully understand conversations, written or spoken directions, and other daily interactions. The proposed research will investigate whether deficits affecting how quickly people with aphasia access words contribute to sentence comprehension impairments. These studies will provide a deeper understanding of the underlying nature of sentence comprehension impairments, which is an important step on the road to developing more effective tools for diagnosis and evaluation.
