Below are descriptions of some of our current and past projects.

Memory and Learning Phenotypes as a Biomarker of Long-Term Outcome in Traumatic Brain Injury 

A critical gap in the literature concerns the question of why some individuals with traumatic brain injury (TBI) respond well to a given treatment while others do not, and what factors contribute to long-term outcome. This lack of knowledge represents a significant challenge for clinicians making decisions about the appropriateness of a given treatment for a particular patient and for clinical researchers who strive to develop new therapies and must determine candidate eligibility for clinical trial research. We propose that an individual’s memory and learning profile, or phenotype, is a critical factor in determining the appropriateness and success of a given intervention. Such phenotypes are key to understanding mechanisms of change in rehabilitation, and linked to a range of real world abilities critical for societal reintegration. Testing whether we can establish a reliable phenotype and demonstrating these relations is the objective of the current project.

This project is supported by a Switzer Distinguished Research Fellowship from NIDILRR (National Institute on Disability, Independent Living, and Rehabilitation Research, 2018-2019).

Hippocampal contributions to language processing and use

Our group has proposed that the hippocampus is a key contributor to language use and processing. Specifically, we proposed that many of the processes by which we produce and understand language also place high demands on and receive contributions from the hippocampal declarative memory system (Duff & Brown-Schmidt, 2012; 2017). This proposal has its roots in the observations that while individuals with hippocampal amnesia are within normal limits on standardized tests of language, their language use differs in striking ways from their healthy peers. This proposal goes against the historical view that amnesia is a pure deficit in memory leaving other cognitive domains, like language, intact. Combining a neuropsychological approach with situated discourse analysis and eyetracking, our work has provided extensive evidence that the hippocampus contributes to language use and processing and argues that the network of neural substrates and cognitive process that support language use and processing be extended to include the hippocampal declarative memory system.

This project is supported by NIH (National Institute on Deafness and Other Communication Disorders, R01 DC011755; Co-PI, Sarah Brown-Schmidt, 2012-2019).

Hand gesture as a window into the cognitive and neural links between language and memory

Attempts at linking memory and language have largely neglected that language is inherently multimodal; our language is commonly accompanied by meaningful, spontaneous movements of the hands and arms that can communicate information. Gesture, by communicating visually and motorically, can convey information not present in spoken language. This suggests that gesture may reflect content that is qualitatively different from that in speech, potentially communicating aspects or types of memory representations that are different from what is in spoken language. In this project, we exploit gesture’s unique communicative nature to examine how it engages and affects specific types of memory during language use. We investigate whether: 1) gesturing while retelling a narrative affects memory for the content of the narrative, and whether this memory enhancement relies on non-declarative memory mechanisms; 2) focusing on gesture’s integration with spoken language, whether this integration can rapidly affect memory representations during language processing; and 3) whether gesture production can signal changes in memory states via non-declarative mechanisms, even when this is not evidence in speech. This work will elucidate the memory mechanisms that are engaged in language use and will for the first time bridge theories of memory with theories of multimodal language use, offering a richer and more complete account of the relationship between memory and language.

This project is supported by NIH (National Institute on Deafness and Other Communication Disorders, F32 DC016580 to Caitlin Hilverman, 2017-2019).

Social perception and social communication following traumatic brain injury 

Individuals with TBI report difficulty in social situations and difficulty with a range of social behaviors. There is little evidence that treatment of these problems generalizes beyond the therapy room to everyday social interaction. We proposed that treatments may fail because clinicians are targeting the wrong problem, as current therapies focus on re-teaching “appropriate” behaviors (e.g., training eye contact or turn-taking), without considering the underlying causes of these behaviors. Our work has aimed to identify the underlying mechanisms of impairment in social perception and communication in individuals with TBI.

This project was supported by NIH (National Institute on Deafness and Other Communication Disorders, R01 DC011755; PI, Lyn Turkstra, 2012-2018).