Characterizing Episodes of Lucidity in Dementia Using Observational and Applied Computational Linguistics Approaches - PROJECT SUMMARY/ABSTRACT Individuals with Alzheimer’s disease and related dementias (ADRD) demonstrate heterogeneous cognitive, functional, and behavioral responses to disease progression, yet underlying sources of these variations remain poorly understood. Fluctuations in communication abilities in particular have important implications for care and attitudes toward individuals with ADRD. Of particular interest is the occurrence of episodes of lucidity (EL) in advanced disease stages, which are characterized by the manifestation of spontaneous, meaningful, and relevant communication abilities that were previously believed to be irretrievable. Reports suggest EL are transient and most likely to occur near end of life, yet empiric evidence documenting these events is extremely limited. Efforts to better understand, and ultimately define EL, are hindered by underdeveloped methodological approaches for capturing and characterizing these events. While underutilized in ADRD research, audiovisual observation is well-suited to addressing these gaps, as these data provide an objective data source and enable a robust assessment of verbal and nonverbal communication, the primary means through which EL are observed. Our long-term objective is to clarify conceptual, operational and epidemiologic understandings of EL in ADRD. Our short-term objective is to establish the necessary foundational data and infrastructure to accelerate systematic investigation of EL. To advance these goals, we will develop feasible and acceptable procedures to enable capture of longitudinal audiovisual data of targeted populations and timeframes to maximize opportunities for detecting EL; these rich data sources will then be analyzed via computational linguistic and sequential analysis (timed-event) methods, to assemble a robust, fully characterized understanding of the linguistic, non- linguistic, and non-verbal communication features of EL along with the specific temporal qualities of these events. In the R21 Phase, we will demonstrate the feasibility of collecting and sharing longitudinal audiovisual data among PLWD near end of life through a mixed-methods feasibility study to determine key ethical and practical considerations (R21 Aim 1); and evaluate usability, reliability and capture rate for coding of verbal/nonverbal indicators of EL from collected audiovisual data using computational linguistic and timed-event methods (R21 Aim 2). The R33 Phase will harness procedures optimized in the R21 phase to expand data collection and develop more robust estimates of EL frequency. Specifically, we will expand longitudinal audiovisual observations of persons with ADRD near the end of life to obtain initial estimates of EL frequency, describe event attributes, and inform the development of definitions for EL (R33 Aim1); and establish a repository of longitudinal audiovisual observational data and a secure data sharing platform (R33 Aim 2). Impact: Findings from this research will set the stage for extension and validation of urgently needed objective measurement for EL in ADRD and provide a critically needed foundation for future systematic investigation of lucidity in ADRD. The objectives of this proposal are directly responsive to national ADRD research priorities and the NIA mission.