Browsing by Subject "Traumatic Brain Injury"

Now showing 1 - 6 of 6
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    Canadian CT Head Rule is an Effective Clinical Screening Tool in Minor Head Trauma Cases.
    (2010-11-02) Donald, Bryan
    The Canadian CT Head Rule is a simple screening tool used in cases of adults with minor head trauma. It can identify patients needing surgery 100% of the time while limiting the number of patients needing head CT to only 32% of those with minor head trauma and a loss of consciousness.
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    Injury-induced neuroinflammation alters addiction behavior
    (2022-12) Emmitt, Nicole
    Traumatic brain injury (TBI) affects 64-74 million people every year worldwide. A history of mild brain injury increases the risk of substance use disorder (SUD) by 2-6 times that of the general population. With the rise of the opiate epidemic, it is imperative to understand the link between TBI and opiate use disorder. Therefore, a model of mild TBI was developed in mice. Mice that received mild TBI had a transient motor deficit at the acute stage of injury and a long-term spatial learning deficit at the chronic stage of injury. The innate immune response in the brain was active at the acute and chronic stage, with macrophage and neutrophil infiltrate peaking at 3 days post injury (DPI), and an increase in the activated macrophage phenotype at both 15 and 30-DPI. Next, to understand how drug seeking behavior is modified, mice with mild TBI or sham injury were subjected to intravenous (IV) self-administration and conditioned place preference (CPP) behavioral assays to evaluate drug seeking behavior. Injured mice had increased consumption of and preference to morphine. The innate immune response was also altered after IV self-administration, with increased macrophage and neutrophil infiltrate on the side ipsilateral to injury. Furthermore, both IV self-administration and CPP with morphine resulted in increased lymphocyte infiltrate on the side ipsilateral to injury. Considering the increased inflammation observed due to morphine, the neuroinflammatory response to a consistent clinical dose morphine was examined, since the majority of people are first exposed to opiates through prescription for pain relief. After TBI or sham injury, mice received morphine twice daily (5mg/kg) for up to 15 days. A biphasic immune response was observed to this dose of morphine with increased macrophage infiltrate and a lymphocyte infiltrate at 15-DPI. This was accompanied by a dynamic, temporally distinct cytokine response, a decrease in the phagocytic activity of macrophages and microglia at 15-DPI and increased leakage of the blood brain barrier in the mid brain. Results from these studies demonstrate a novel increase in the proinflammatory response at the chronic stage of traumatic brain injury when exposed to morphine. The models developed here will provide new insights to help identify new targets to reduce the risk of SUD following TBI.
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    Is metamemory implicit? evidence of priming and antipriming in individuals with and without traumatic brain injury.
    (2009-07) Ramanathan, Pradeep
    Implicit memory refers to the phenomenon of prior exposure to a stimulus influencing cognitive processing on subsequent exposure to that stimulus, irrespective of one's awareness of such influence. Metamemory refers to the presumably explicit act of making judgments about one's memory. Theories vary regarding possible relationships between implicit memory and metamemory, with mixed findings of previous research. Some researchers argue that there is no relationship, that metamemory does not rely on input from implicit memory only on explicit memory (Hart, 1965; Koriat, 1995), while others argue that metamemory is driven only by implicit processes (Reder & Schunn, 1996). Still others argue that the metamemory system relies on input from both implicit and explicit memory (Vernon & Usher, 2003). To date, no study has examined whether subliminal masked priming and antipriming can influence individuals' metamemory judgments of learning (JOLs). The present study independently varies subliminal masked priming conditions (using baseline, prime, and antiprime conditions) and observes the influence on participants' immediate and delayed JOLs and relative predictive accuracy, in a paired associate learning task. This study also examines long term repetition priming and antipriming (measured in a visual object identification task) to determine whether the magnitudes of these effects correlate with those found in the paired associate learning task. Both neurologically normal individuals and those with traumatic brain injury (TBI) participated in this study. Metamemory deficits are common after TBI. Thus, inclusion of this clinical population in the present study is critical in evaluating whether or not such individuals' metamemory judgments can be influenced by, or correlated with, priming or antipriming. Furthermore, to date, no study has examined antipriming among TBI survivors; therefore their participation in the visual object identification task will shed light on antipriming in that population, and will provide a perceptual implicit memory benchmark against which to compare any findings of implicit metamemory. Results demonstrate no main effect of subliminal masked priming and antipriming on participants' metamemory judgments for JOL ratings, predictive accuracy (gamma correlation), or response times for judgments of the likelihood of future recall of target words. However, there was a trend towards an interaction effect of priming and JOL timing (i.e.: immediate vs. delayed), such that JOLs made immediately after study were higher for the primed items than for the baseline or antiprimed items. In contrast, antipriming did significantly influence explicit recall, with slowing of explicit recall response times for antiprimed target words, relative to word-pairs in the baseline condition. Difference scores between JOL ratings and recall accuracy reflected overconfidence among TBI survivors, and good calibration among controls. There was a significant decrease in the overconfidence of TBI survivors for antiprimed items. However, much of this lowering was caused by an increase in recall accuracy for antiprime items. In the visual object identification task, antipriming was robustly observed for both participant groups; there was significant slowing observed for responses to antiprimed items. Finally, a mild positive correlation between the degree of priming for visual object identification and the degree of priming of relative predictive accuracy in the paired associate learning task was found across participants. The present research finds weak evidence for the role of implicit memory, in the form of masked priming and antipriming, in JOLs and relative predictive accuracy in paired associate learning. Future research providing masked priming stimuli immediately prior to the solicitation of JOLs may address possible attenuation of such effects which may have occurred in the present study. Additionally, using numbers from the JOL rating scale as subliminal stimuli may shed additional light on the type of representation taken as input by the metamemory system. Finally, exploration of long term priming and antipriming of metamemory in the TBI population should be undertaken to determine whether or not there is a priming benefit to metamemory judgments through supraliminal implicit memory.
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    Public Perceptions of Traumatic Brain Injury: Knowledge, Attitudes, and the Impact of Education
    (2015-05) Schellinger, Sarah
    Background: There are currently over 5 million Americans living with disabilities resulting from traumatic brain injury (TBI; Faul, Xu, Wald, & Coronado, 2010). Despite this high prevalence, previous research suggests that the public lacks adequate knowledge about TBI and endorses negative attitudes towards individuals with TBI (e.g., Ralph & Derbyshire, 2013). As a result, researchers have called for initiatives to heighten public awareness and provide education about brain injury. However, there is little research on whether such initiatives are effective. In addition, research documenting recent changes in public knowledge and attitudes about brain injury in the United States are lacking. Purpose: This dissertation has four primary goals: 1) To determine the level of knowledge about TBI among the general population and to identify predictors of knowledge, 2) To describe attitudes about TBI endorsed by the general public, to determine their relationship with knowledge, and identify predictors of attitudes, 3) To determine the relationship between attitudes and intended behaviors, and 4) To determine if an educational video will result in improved knowledge about brain injury, more favorable attitudes towards individuals with TBI, or differing intended behavior. Method: This study employed a between-groups design to evaluate public perceptions of TBI among the general public and to evaluate the impact of an educational video. A total of 392 members of the general public were randomly assigned to a control or experimental group. All participants completed a series of 4 measures: a background questionnaire containing items about demographics and prior experience with TBI, a modified version of the Common Misconceptions about TBI questionnaire, a modified version of the Multidimensional Attitude Scale, and two questions relating to intended information-seeking behaviors. Prior to completing the final three measures, participants in the experimental group viewed an educational video about TBI. Participants in the control group viewed an unrelated video. Results: Results indicated that the general public endorses a number of misconceptions about TBI, but harbors largely favorable attitudes towards individuals with TBI. On the whole, few variables related to demographic characteristic or prior TBI experiences predicted knowledge and attitudes. Similarly, only relatively weak associations between knowledge, attitudes, and intended behavior emerged. Participants who viewed the educational video demonstrated higher TBI knowledge, but did not display more favorable attitudes than participants who viewed the unrelated video. Implications: Results from this study support continued efforts to educate the public about TBI. Furthermore, continued research on public knowledge, attitudes, and behavior is needed.
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    Remembering to Remember: Metamemory Judgments of Prospective Memory after Traumatic Brain Injury
    (2016-06) O'Brien, Kathryn
    Background: Impairments to prospective memory (PM) are ubiquitous after traumatic brain injury (TBI). PM is remembering to complete an intention at a future time – like picking up milk on the way home – and is critical for independent living. PM includes two primary components: recognizing the CUE when a task should occur, and recalling the TASK to be completed. Many adults use memory aids for PM, such as notes or phone alarms. Such strategy use is related to metamemory judgments, or self-assessments of future success. Purpose: The purpose of the current study was to examine how adults with and without TBI consider PM performance. Research questions compared predictions and recall performance at PM, as well as the relationship between PM metamemory predictions and standardized assessments of cognitive function. Methods: Eighteen adults with chronic moderate to severe TBI and 20 matched healthy controls played Tying the String, an online simulated workweek PM game. Participants studied PM items and made two judgments of learning about the likelihood of recognizing a PM CUE, and of recalling the PM TASK. Participants also completed a standard neuropsychological battery. Results: Participants with TBI were less confident in future recall than healthy controls and both groups were less confident about the TASK. For recall performance, healthy controls performed similarly across the CUE and TASK. In contrast, adults with TBI at times recognized a CUE, but were unlikely to remember the corresponding TASK. Absolute difference scores of metamemory accuracy showed that healthy adults were underconfident across PM, whereas adults with TBI were overconfident about the task. Adults with TBI adjusted judgments downward as the game progressed at a rate greater than healthy controls. During standardized testing, participants with TBI chose to use PM strategies, but those strategies were not effective at triggering PM recall. Discussion: Participants with TBI adjusted metamemory expectations downward, but not enough to account for poor recall performance. Individuals with TBI have metamemory awareness to use strategies, but deficient monitoring of memory performance results in incomplete metamemory knowledge. Future work should address linking PM metamemory monitoring with strategy use to direct intervention approaches.
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    Traumatic Brain Injury Rehabilitation Intermediate Representation
    (2013-09-17) Grove, Michael
    Traumatic Brain Injury Rehabilitation "Intermediate Representation" developed in Michael Grove, PhD dissertation (September, 2013). This is an artifact which informed the subsequent development of the TBI rehabilitation ontology also archived in the conservancy.