The various patterns of impairment and recovery that are observed in the other projects provide an opportunity to test and refine theories of language processing in the brain. As our understanding of these relationships improve, we aim to provide better tools for diagnosis and targeted treatment of speech and language impairments.
Model-driven therapies are only as effective as the models that drive them. Therefore, any program that seeks to use models of language function to guide remediation of language deficits must take model development seriously. Minimally this involves staying on top of the most recent advances in understanding the functional anatomic organization of language. The premise of Project 4, however, is that we can do better than merely drawing on independent advances in basic science. We propose instead to implement a truly synergistic translational relation between basic and clinical science: while Project 1 uses existing theoretical constructs to inform aphasia therapy, in Project 4 we will use the clinical data as a means to advance the basic models themselves and inversely to use basic models as a means to fine-tune diagnostic classifications that can inform treatment programs.
Hickok and Poeppel’s dual stream model is among the most influential current frameworks for understanding the functional anatomy of language (Hickok & Poeppel, 2007). By synthesizing a broad range of findings in psycholinguistics and neuroscience, the theory associates various computational processes that support speech and language with specific neuroanatomical networks. In Project 4, we will continue developing these ideas by building computer programs that mimic speech production processes and the various ways in which they can break down in aphasia (e.g., Walker & Hickok, 2016). If the behavioral performance of real patients can be closely approximated, the computational components may provide better targets for treatment than the overt symptoms themselves, and the effects of treatment may be better understood within an explicit theoretical framework.
Hickok, G., & Poeppel, D. (2007). The cortical organization of speech processing. Nature Reviews Neuroscience, 8(5), 393-402.
Walker, G. M., & Hickok, G. (2016). Bridging computational approaches to speech production: The semantic–lexical–auditory–motor model (SLAM). Psychonomic Bulletin & Review, 23(2), 339-352.