Poster Session 08 Program Schedule
02/16/2024
01:45 pm - 03:00 pm
Room: Shubert Complex (Posters 1-60)
Poster Session 08: Cognition | Cognitive Reserve Variables
Final Abstract #35
Chronic Stress Predictors of Immediate vs. Delayed Memory Scores in A Military Veteran Population
Laura Jones, University of Florida, Gainesville, United States
Sarah Bottari, University of Florida, Gainesville, United States
John Williamson, University of Florida, Gainesville, United States
Damon Lamb, University of Florida, Gainesville, United States
Category: Memory Functions/Amnesia
Keyword 1: memory disorders
Keyword 2: traumatic brain injury
Keyword 3: post-traumatic stress disorder
Objective:
To determine the effects of chronic stress factors on memory in Veterans with history of combat exposure with and without PTSD and mild TBI. Chronic stress adversely affects systemic and brain health, neurophysiological regulation, and other behavioral outputs such as memory performance. Memory complaints are common in Veterans with history of combat exposure and are affected by traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD). Understanding the relationship of differences in brain structure associated with chronic stress to specific memory deficits may lead to improved and targeted treatments in behavioral and cognitive therapies.
Participants and Methods:
Combat veterans (n = 59) between the ages of 18 and 55 were recruited as part of a larger study. Average age was 31.51 (SD = 6.29) and 92% were male. Freesurfer and Tracula were used to establish specific white matter region of interest characteristics and regional volumes via 3-T MRI. Indicators of chronic stress included: PTSD Checklist Military (PCLM) Hyperarousal and Total Scores, Symptom Checklist 90 – Revised (SCL-R 90) Anxiety T-Score, and average RSA. Brain ROIs included Left/Right Hippocampal Volumes, Left/Right Uncinate Fasciculus Fractional Anisotropy (FA), and Left/Right Amygdala Volumes. These were z-scored, and a Least Absolute Shrinkage and Selection Operator (LASSO) regression model was performed to determine the best fit model for predicting Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) List Learning and Recall raw scores.
Results:
Cross validation determined an optimal lambda value of 0.56 for the RBANS List Recall LASSO model (F = 2.203, p = 0.023). Using this lambda value, the LASSO regression indicated that a four-predictor model was the with PCLM Total Score (β = -2.14, p = 0.01), PCLM Hyperarousal Score (β = 2.82, p > 0.001), Left Hippocampal Volume (β = 1.16, p = 0.03), and Right Hippocampal Volume (β = -1.31, p = 0.01) as the predictors with non-zero coefficients. The overall model and no predictors for RBANS List Learning Raw score were significant (F = 1.527, p = 0.14).
Conclusions:
Our investigation leveraged a combination of neuroimaging, physiological measures, and self-report questionnaires and found distinctive stress factors differentially impact components of memory. A self-report of PTSD symptomology and hippocampal volume best predicted RBANS List Recall memory. We found elevated PTSD severity predicted lower recall performance but reported physiological arousal predicts higher recall scores. Hippocampal volume was also a significant predictor for delayed memory performance and dendritic quality of the hippocampus is a known indicator of chronic stress. This research contributes to advancing our understanding of the intricate relationships between chronic stress, memory performance, and neurophysiological outcomes in military veterans.
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