Language Processing in Context Following Traumatic Brain Injury

Cognitive-communication disorder is a common and chronic consequence of moderate-severe traumatic brain injury (TBI) and a major source of disability that is associated with negative outcomes including reduced social participation, reduced employment, and reduced life satisfaction. Despite intensive research efforts, no significant reduction in TBI related disability has been documented over the past 20 years. This renewal application leverages our discovery in the prior award period of striking deficits in language processing in context to offer a new direction in the empirical study of cognitive-communication disorder in TBI. By determining the underlying mechanisms and timescale of these deficits, the proposed work will provide the necessary explanatory framework to support the future development of successful rehabilitation efforts. At the heart of the proposed work is the new understanding that the reach of cognitive communication disorder is more extensive affecting more aspects of language than previously appreciated and changing in magnitude over time scales not previously examined. In showing that cognitive-communication disorder extends considerably beyond deficits in communication (beyond the level of the utterance in discourse and conversation) to include deficits in the real- time processing of individual words, phrases, and sentences, the proposed work promises to afford a richer understanding of which language processing mechanisms are impaired in TBI. In showing that the magnitude of cognitive-communication disorder impairs the ability to learn from communicative experiences and that deficits grow over timescales of minutes to a week, the proposed work provides new insight into the implications of these impairments for a range of real-world interactions and into the challenges of their clinical management. Building on these discoveries and new methodological innovations developed in the prior award period, this proposal is organized around three specific aims: (1) To investigate the mechanisms of the language processing deficit in TBI; (2) To investigate the ability to learn and adapt from language experience and use in TBI; (3) To identify the predictors of language processing impairment at an individual level and to link impairment to functional outcomes. The results of this research will provide the explanatory framework necessary to set an agenda for future work developing new assessments for earlier identification and prediction of deficits and for development of empirically based interventions. This proposal is unique in the field and uniquely promising for understanding cognitive-communication disorder following TBI and, ultimately, improving communication outcomes and reducing disability.