Russell, Kathryn Courtney
(2010)
Hemispheric and Executive Influences on Low-Level Language Processing After Traumatic Brain Injury.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Traumatic brain injury (TBI) has great impact, both to public health as well as to theindividuals who sustain one. Some of the most problematic deficits after TBI arise in cognitiveareas like executive functioning and language. Language deficits at the level of discourse arecommonly reported (e.g., Snow, et al., 1998), but evidence of lower-level language problems hasbeen more scarce. One possible explanation for that pattern of findings (e.g., McDonald, 1992) isthat underlying executive deficits are responsible for the discourse problems. A goal of the current studies is to see, then, what effect variations in executive demands have on lower-level language after TBI. A second goal is to begin to examine mechanisms for those processing differences. The most common neuropathology after TBI is diffuse axonal injury (DAI), which has been estimated to be present in a large percentage of cases, and commonly affects the corpus callosum (Pittella & Gusmão, 2004). Based on these facts, it was hypothesized that altered interhemispheric communication might be involved in the cognition problems faced by peoplewith TBI. To examine the effects of hemispheric communication and executive demands onlanguage processing after TBI, two behavioral experiments using split visual hemifieldpresentation and one functional connectivity analysis of resting-state fMRI data were conducted. The task in the first experiment was semantic priming with lexical decision. As compared to controls, participants with TBI showed a stronger right visual field (RVF) advantage and selective impairments suggestive that language was primarily affected when executive demands were higher. The second experiment confirmed these results with a verb generation task collecting vocal latencies (from Chiarello, et al., 2006). Finally, the functional connectivity analysis compared connectivity values between right and left hemisphere areas thought to be involved in language and executive functioning. This analysis, while preliminary, provided some evidence suggesting that persons with TBI may have higher functional connectivity at rest than matched controls, especially for right hemisphere connections and links to anterior cingulate cortex. Together these findings begin to reveal a complex picture where hemispheric and executive factors have important bearing upon language processing in people with TBI.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
| Creators | Email | Pitt Username | ORCID  |
|---|
| Russell, Kathryn Courtney | kcr9@pitt.edu | KCR9 | |
|
| ETD Committee: |
| Title | Member | Email Address | Pitt Username | ORCID |
|---|
| Committee CoChair | Ricker, Joseph | | | | | Committee CoChair | Fiez, Julie | | | | | Committee Member | Perfetti, Charles | | | | | Committee Member | Wheeler, Mark | | | |
|
| Date: |
28 January 2010 |
| Date Type: |
Completion |
| Defense Date: |
28 August 2009 |
| Approval Date: |
28 January 2010 |
| Submission Date: |
10 November 2009 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Psychology |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
closed head injury; cognition; corpus callosum; fcMRI; traumatic axonal injury |
| Other ID: |
http://etd.library.pitt.edu/ETD/available/etd-11102009-141438/, etd-11102009-141438 |
| Date Deposited: |
10 Nov 2011 20:04 |
| Last Modified: |
15 Nov 2016 13:51 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/9625 |
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