Objective: Judicious selection of potential liver transplant candidates and close monitoring of progress are essential to successful outcomes. Pretransplant psychosocial evaluations are the norm, but the relationship between psychosocial (and neurocognitive status) and longer term medical outcomes is understudied. This exploratory study sought to examine the relationship between objective measures of pretransplant psychosocial and neurocognitive status and service utilization, transplant status, and all-cause mortality. Methods: This retrospective chart review examined outcomes among 108 psychiatric, high-risk liver transplant candidates up to four years following initial evaluation. Predictor variables of outcomes included demographic, medical, neurocognitive, psychological, and mental health treatment variables. Results: Transplant status and neurocognitive functioning were independently associated with all-cause mortality. None of the other variables were associated with outcomes. Conclusions: Better neurocognitive functioning in high-risk liver transplant candidates may allow for greater involvement in medical care and/or compliance with treatment recommendations. More aggressive assessment and management of neurocognitive dysfunction may improve outcomes. Objective measures identified significant psychopathology typical of liver transplant candidates but were not associated with outcomes; engagement in specialized mental health care may have attenuated this relationship. Further study is needed to better understand the relationship between psychosocial functioning and outcomes.

A child’s executive function (aspects: working memory, response inhibition, and set-shifting between sets of rules) capabilities have been found to strongly relate to their mathematics skills. However, while the relationship has been strongly supported by researchers, a consensus has not been reached regarding the specifics of the relationship between executive function and math skills, including which executive function aspect is most predictive of mathematical performance and the differences in said relationship that might be found when examining both numeracy, such as counting skills and basic operations, and geometry skills. The lack of consensus may be in part because researchers have assessed both executive function and mathematics in a variety of ways. To address the consensus issue, this study used a panel of face-to-face measures of executive function, a paper-and-pencil measure of executive function, and a broader measure of mathematical performance than has typically been used, one including numeracy and geometry. Using a longitudinal approach, with two assessment periods about six months apart (M = 5.61 mos., SD = 1.12), this study examined this relationship among 118 children (61 girls), ages 39 to 68 months (M = 52.58, SD = 6.35), living in both rural (n = 64) and urban (n = 54) areas in a state in the western United States. A longitudinal approach allowed for comparisons between results from the two assessment periods. Results suggest that while numeracy and geometry skill among preschool-age children are connected, there are some independent elements. Additionally, because of rapid cognitive growth, age is an important factor when selecting both assessments and analytic strategies, as statistically significant variations in the predictive power of measures and strategies occurred between assessment periods. Connections between younger children’s executive function and numeracy skills appeared to be best assessed through a non-number-based measure, older children’s numeracy ability can be predicted by a greater variety of executive function measures. Face-to-face executive function measures included in this study were more predictive of numeracy skill than geometry skill, and geometry skill appears to be connected to inhibitory control. Differences between rural and urban children were found on numeracy skill and working memory ability, but not on geometry skill. Statistically significant differences by gender were found on an inhibitory control measure, with boys scoring higher than girls in our sample.

The prevalence of alexithymia, a condition characterized by difficulties identifying and verbalizing one’s emotions, increases across the lifespan, with older adults reporting greater alexithymic features than young and middle-aged adults. This late-life increase in alexithymia may be the product of age-related decline in prefrontal brain circuitry implicated in emotional awareness and executive processes, notably in the anterior cingulate cortex (ACC). There is a dearth of research on the link between executive function and alexithymia in healthy adults. This study determined associations between alexithymia and executive function in healthy younger and older adults. Higher alexithymia scores were predicted to be associated with poorer performance on measures of executive function, specifically one that taps into ACC function (i.e., verbal fluency). Sixty-five young adults and 44 older adults completed the 20-item Toronto Alexithymia Scale, three executive function tasks (Verbal Fluency, Design Fluency, and Trail Making), assessments of memory and verbal ability, and a self-report measure of depressive symptoms. Greater total alexithymia and difficulties describing feelings (a dimension of alexithymia) were associated with poorer verbal fluency, accounting for age, gender, and depressive symptoms, in the full sample and in older adults, but not in young adults. Findings support the theoretical model that alexithymia is associated with age-related decline in frontal circuitry – possibly specific to declines in ACC functioning. Results provide insight into the possible origins of emotion self-awareness deficits in older adulthood.

No description available.

No description available.

Although there is an abundance of research investigating the effects of exercise on cognitive function, few studies have investigated acute effects of exercise on performance of tasks involving executive function. Furthermore, the effects of different exercise intensities on multiple tests of executive function have received little attention. The purpose of this study was to examine the acute effects of 20-minutes of stationary cycling exercise at varying exercise intensities on executive function performance and to determine these acute effects immediately following exercise as well as after 10 and 30-minute delays following exercise. University students (N = 88) completed baseline measures of executive function (stop-signal task [SST] and Stroop task [ST]) and a graded cardiovascular exercise test on Visit 1. On Visit 2, participants were stratified by gender and fitness level and randomized to one of four conditions: high-intensity interval training (HIT), high, moderate or low-intensity steady-state exercise performed on a cycle ergometer. The ST and SST were performed immediately following exercise and again at 10- and 30-minutes post-exercise. Immediately following exercise, ST response times were significantly different (p < .05), demonstrating faster response times for the high and moderate intensity exercise (p < .05), while improvements in SST response inhibition were revealed for the HIT (p < .01) condition. At 10-minutes post-exercise, moderate and low-intensity conditions revealed improvements in ST response times (p <.05), with enhanced SST response inhibition evident in the HIT, moderate and low-intensity conditions (p < .05). At 30-minutes post-exercise, ST response times continued to show improvements from baseline for the moderate and low-intensity conditions (p < .05), while SST response inhibition trended back towards baseline levels (p > .05). The present outcomes demonstrate beneficial effects of exercise, regardless of intensity, for up to 38 minutes post-exercise. Future research should focus on mechanisms that would account for these effects and factors that support enhanced executive function performance with exercise training. / Thesis / Master of Science (MSc)

Higher cardiorespiratory fitness (CRF) is associated with better executive function and mental health in neurotypical populations. However, these associations warrant investigation for adults with attention deficit hyperactivity disorder (ADHD) who experience executive dysfunction and worse mental health. Adults with ADHD also tend to have lower engagement in physical activity, which contributes to CRF, but the reasons for this are unknown. Using mixed methods, the purpose of this dissertation was to explore associations between CRF and executive functions (Study 1), and mental health (Study 2), and to understand barriers and facilitators to physical activity in an adult ADHD sample (Study 3). Data from Study 1 reveal the association between higher CRF and better inhibitory control; surprisingly, the same associations with CRF were not observed for cognitive flexibility and working memory, suggesting a selective association between CRF and inhibitory control. In Study 2, although adults with ADHD reported significantly higher symptoms of depression, anxiety, and stress than controls, those with higher CRF had better mental health. Together, the findings from Studies 1 and 2 suggest that physical activity interventions aimed at increasing CRF may provide adults with ADHD support for symptom management and mental health. Finally, Study 3 documents the unique barriers and facilitators to getting physically active as described by adults with ADHD. Through semi-structured interviews, the results revealed unique ADHD-related barriers and facilitators to being physically active such that their symptoms could act as both a barrier and facilitator depending on the context. Overall, the results of this dissertation provide valuable information for researchers designing future interventions and professionals recommending physical activity for those with ADHD, with the ultimate goal of creating an inclusive context for movement that is more enjoyable, feasible, and promotes adherence over the long term. / Thesis / Candidate in Philosophy

No description available.

The purpose of the present study was to examine the associations among teacher ratings of attention deficit hyperactivity disorder (ADHD) symptomology and executive functioning (EF) skills with reading comprehension and its underlying components reflected in the Simple View of Reading (SVR) including decoding and language comprehension ability. A total of 27 second grade (n = 10), third grade (n = 12), and fourth grade (n = 5) students were recruited for the study. Standardized assessment measures were used to capture word reading, decoding, reading comprehension, semantics, grammar, listening, phonological processing, and working memory. Teacher questionnaires were used to assess ADHD symptomology and EF ability in participants. Correlation analyses were conducted to explore the associations among teacher ratings of EF and ADHD, reading comprehension, and its subskills outlined in the SVR. A series of hierarchical regression analyses were performed to identify whether teacher ratings of ADHD or EF added unique variance to reading comprehension after controlling for word level reading and language comprehension skills. Results from the current study give further support for the SVR as an effective model for conceptualizing reading comprehension. An association between EF difficulties and poor word reading, in addition to weaker reading comprehension skills, was identified. These findings highlight the need for further research examining the role that EF plays in reading comprehension and its underlying components in order to better support struggling readers. / Graduate

This study was an investigation of the association between executive functioning (EF) ability and language development in the latter half of the second year. Fifty-five typically developing 18- month-olds were brought into the lab. The elicited imitation with inappropriate object substitution (EIIOS) task was used as a developmentally sensitive measure of EF. Language acquisition was assessed using a real-time word learning task as well as a parent report measure of vocabulary size (MacArthur-Bates Communicative Development Inventory: Words and Sentences Version). Contrary to expectations, very few statistically significant associations were found between the EF measure and either language measure. Despite these findings there is still a need for research to identify an appropriate measure of EF in the latter half of the second year.