The aim of our research is to elucidate the cognitive and neural bases of human memory, and to better understand the mechanisms of cognitive impairment in clinical syndromes in which memory is one of the presenting complaints. Our cognitive neuroscience studies of memory employ both a neuropsychological approach, focusing on the cognitive processes that are affected in patients with medial temporal lobe (MTL) lesions and patients with frontal lesions, and a neuroimaging approach, focusing on the structural and functional basis of cognitive performance in healthy and neurologically impaired individuals. Our clinical studies are exemplified by behavioral and neuroimaging studies in patients with cardiac arrest and mild TBI (mTBI).
A major focus of our lab is the study of patients with selective amnesia secondary to medial temporal lobe (MTL) damage. Our past work has been centered largely on impairments in long-term memory, but recent work has extended the scope of our investigation to other domains of memory and cognition. For instance, we are interested in understanding the conditions under which forms of memory previously thought to be independent of the MTL, such as short term memory and reinforcement learning nonetheless are impaired in patients with MTL lesions. Such findings compel a re-conceptualization of the paradigmatic view that the MTL is important only for long-term declarative memory. We are also interested in understanding the role of MTL and frontal regions in apparently non-memorial domains such as future thinking, decision-making, and creativity. As part of this work, we examine how emotion and memory interface in the service of future-oriented behavior.
Our clinical work currently focuses primarily on veterans who have suffered blast-related mTBI during deployment. The behavioral component of this work examines the role of mTBI and psychiatric co-morbidities in the symptom complaints and neurocognitive performance of veterans, and how psychosocial and cognitive treatment approaches can ameliorate these chronic effects. Because cognitive behavioral interventions in PTSD require both access to trauma memory and future-oriented problem solving, we are also interested in assessing how mTBI impacts trauma memory and future thinking in PTSD. This work directly applies our cognitive neuroscience insights to the clinical realm. In concert with the behavioral work, neuroimaging studies examine the integrity of white matter tracts and functionally connected networks in search of biomarkers that may distinguish mTBI from PTSD. Using an imaging-genetics approach, we are also starting to examine whether genetic risk and/or protection factors may moderate the link between blast-induced mild TBI and subsequent neurodegenerative disease.