The purpose of this study is to investigate, through observation and analyses of videotaped records, how frontotemporal dementia patients, especially of the apathetic variant, and their interlocutors negotiate meaning and build understanding during ordinary interactions. What social behaviors and discourse practices do FTD patients employ? Do their behaviors and practices meet interlocutors' expectations or do interlocutors treat such behaviors as aberrant and in need of repair? If so, how do interlocutors manage such behaviors and practices? And how do FTD patients respond to such management attempts? Can the observed practices of FTD patients be attributed to the neurodegenerative dementia or are the contexts in which they now find themselves relevant to their practices? These questions are addressed through the careful analysis of videotaped naturally occurring interaction between three FTD patients (two of the apathetic variant and one of the disinhibited variant) and their frequent interlocutors.

This dissertation employs ethnographic methods, particularly participant-observation and interviews to document the common social behaviors and discourse practices of FTD patients as they are observed by caregivers and researchers. The ethnographic perspective allows a unique longitudinal viewpoint that is useful in understanding the progression of FTD over time as well as behavioral decline. This dissertation also employs conversation analysis (CA) to investigate the multi-layered nature of interaction between patients and interlocutors, specifically the practices that patients employ in natural contexts, and the ways in which interlocutors respond to such practices. Its focus sheds light on how patients' discourse practices are treated as inappropriate by interlocutors. Lastly, this dissertation reviews the brain scans of the patients and outlines the likely brain regions that are relevant to the documented social behaviors and discourse practices presented in earlier chapters.

Analyses of the interactive practices of FTD patients reveal how frontal lobe degeneration affects the patients' social and discourse practices in natural contexts, contexts that include the rich resources available to them that are not always available in a laboratory or controlled clinical setting. Analyses of caregiver responses to the patients' common practices reveal which caregiver practices are effective and allows an exploration of their effects in real time. Such analyses further reveal which patient practices are particularly troublesome for interlocutors and which practices are treated as “requiring” repair and/or management. Exploring the range of caregiver responses also provides insights into the level of stress caregivers often face on a daily basis. This work has clinical implications as well as implications for how we understand normal interaction.