Episodic future thinking is defined as the ability to mentally project oneself into the future into a specific time and place. Episodic future thinking has been explored extensively in neuroscience. However, it has not been determined whether the measurement of episodic future thinking might be valuable in a clinical neuropsychological setting. The current study examined the relationship between episodic future thinking and instrumental activities of daily living (IADLs), which is a domain of adaptive functioning frequently assessed by neuropsychologists to examine independent living potential including the ability to handle finances, prepare food, complete household duties, and manage medications. A secondary aim was to examine whether episodic future thinking is related to IADLs over and above standard measures of cognition. 61 older adults with heterogeneous neurological conditions and 41 healthy older adults completed a future thinking task (the adapted Autobiographical Interview), two measures of IADLs (an informant report measure called the Everyday Cognition Scale and a performance-based measure called the Independent Living Scales), and standard measures of memory and executive functioning. Episodic future thinking was significantly associated with performance-based IADLs when accounting for age, education, gender, and depression (r=.26, p=.010). Episodic future thinking significantly predicted performance-based IADLs over and above executive functioning (R2=.025, p=.030). Episodic future thinking was not predictive of performance-based IADLs over and above memory (p=.157). Episodic future thinking was not significantly associated with informant reported IADLs when accounting for age, education, gender, and depression (p=.284). This study suggests that episodic future thinking is significantly associated with IADLs, beyond what can be accounted for by executive functioning. Episodic future thinking may provide information about IADLs to clinical neuropsychologists so they can improve their recommendations for independent living.

For several years, residents of Cache County, Utah have suffered from the recurrence of what has come to be known as the winter-inversion, or “red-air-day” season. Each year during this season – which occurs primarily in the months of December, January, and February – particulate matter concentrations measuring two and half micrometers or less (commonly known as PM2.5) rise and languish (for periods of days or even weeks) above federally mandated standards, causing extensive harm to community health and confounding what have thus far been the relatively tepid control efforts undertaken by local and state policymakers. Through time-series regression modeling, we establish a statistical relationship between PM2.5 concentrations and vehicle use in Cache County, and further calculate a gas-price elasticity for the region. Next, we analyze the benefits and costs associated with a potential seasonal gas tax which, if set appropriately and enforced effectively, could decrease vehicle use and thereby lower health costs through concomitant decreases in PM2.5 concentrations. Specifically, we find a relatively strong positive relationship between percentage of vehicle trips reduced and associated reductions in PM2.5concentrations, and a gas price elasticity of approximately -0.31 in what we call a “high price variability environment.” Based upon these results, benefit-cost analysis suggests a potentially positive social net benefit for Cache County associated with imposing a seasonal gas tax to reduce PM2.5 concentrations during the winter-inversion season. Our benefit-cost analysis, which uses quantitative estimation techniques on both sides of the ledger, yields a first-of-its-kind social net benefit estimate for controlling elevated PM2.5 concentrations in Cache County through the imposition of a seasonal gas tax.

Impulsivity takes many forms, one of which is termed impulsive choice. Impulsive choice entails preference for an outcome due to its immediacy relative to more optimal outcomes that take longer to come to fruition. For example, one may wish to have another serving of a decadent dessert after dinner—but doing so may undermine a longer-term goal of improved health and nutrition. If having the extra serving becomes a habit, the consequences of that choice compound and may lead to, for example, obesity. A high degree of impulsive choice such as this is indeed related to issues such as obesity, drug addictions (e.g., alcohol, opiates), and more; it may also cause these conditions. Because impulsive choice may lead to the development of poor health conditions, being able to reduce impulsive choice may reduce the occurrence of these conditions and/or help treat them. To date, a variety of studies have been conducted to examine ways to reduce impulsive choice, but it was unclear what methods may be most useful for clinical use in humans. Thus, the first portion of the enclosed research was a literature review in which successful methods for reducing impulsive choice were identified. A particular intervention called Episodic Future Thinking (EFT), which entails vivid imagination of one’s future, was one of the most promising found. However, it was unclear if its positive effects on impulsive choice were due to EFT itself or a placebo-like effect, which can arise from being able to guess the purpose of the intervention. The remaining portions of this dissertation focused on determining whether people are able to identify the purpose of EFT, and subsequently, if this awareness accounts for the positive effects of EFT on impulsive choice. Across three experiments, we demonstrated that naïve individuals are able to figure out the purpose of EFT (Experiments 1a and 1b), but that being aware of its purpose is unrelated to its positive effects (Experiment 3). These findings give hope that this intervention could be clinically useful, but it did appear that its benefits did not generalize well to novel settings (Experiment 2). Overall, the results of the research showed that EFT produces genuine changes in impulsive choice, but that further research will need to be conducted to understand why it works, and ultimately, how its generalizability can be increased.

In the United States alone, disability touches the lives of a tremendous amount of people. An increased prevalence of chronic illness, coupled with an aging population means it is likely and perhaps inevitable that everyone will experience disability in one way or another over the course of their lifetime. However not everyone who is disabled is recognized as such. Culturally, the narrative of “the healthy disabled person,” – or someone who is healthy, permanently, predictably, and visibly disabled renders many people with chronic and episodic pain, fatigue, and illness as unrecognizable as disabled. Even though increasing numbers of disability scholars have begun to acknowledge that the embodied experiences of disability are far more fluid than the theoretically static divisions between healthy or ill, abled or disabled allow for, there has been little research that explores the experiences that exist in between these spaces In this dissertation I use narrative analysis to examine “who counts” as disabled in the United States, and why by exploring the interconnected narratives of disability at the cultural, institutional, and personal levels of society. In the first of three substantive chapters I examine cultural narratives about contested illness published in The New York Times between 1999 and 2016. I argue that stigmatization of episodic illness and disability occurs when the reality of lived experiences contradict the cultural assumptions and expectations; namely that health and illness, disability, and ability are natural, discrete, and static states of being for physical bodies. In the second chapter I examine institutional narratives of disability as they are told in town hall meetings for the Americans with Disabilities Amendment Act. I argue that these narratives serve to distinguish between morally good people with disabilities who deserve to be protected and accommodated in the workplace, and those who would use disability as an excuse to take advantage of their employers. In the final substantive chapter, I examine how women with chronic and contested illness reconstruct their identities through narrative in an online forum. I argue that these online spaces are an important site from which these women are able to counter the stigmatization and isolation that results from the dominant narrative that portrays them as morally corrupt. In each of these three chapters I find that the shifting and unpredictable reality of bodies that appear normal, healthy, and abled sometimes, and periodically ill, impaired, and disabled others are at best culturally unrecognizable as disabled and at worst, subject to disbelief and hostility regarding their claims as such. I argue that in order to overcome the stigmatization and disbelief of invisible and episodic disability, we need a cultural reorientation towards the story of disability; one that moves away from the belief that it is something that only happens to a small number of people in society, and towards an understanding of disability as an inevitable experience for the majority of the population; and in doing so works towards a more inclusive society that is designed to meet the needs of an ever changing and diversifying population.

<p>Recurrent stress has been found to impair brain structures essential to memory. The cognitive reserve model suggests that physical activity supplies protection against memory decline in neuropathologies. The purpose of the present study was to explore whether leisure physical activity modifies the predicted negative effect stress has on memory. A sub-sample derived from the Betula Study comprised 267 participants between 50 and 65 years. Memory was assessed by a SPT free recall and stress by a self-report. Low and High frequency exercisers were analyzed separately. After age, sex and education were controlled for in hierarchical regression, results showed that stress significantly improved memory performance in Low exercisers but no significant effect in High exercisers. Thus, frequency of physical activity did not explain variation in memory performance. However, higher age did not have a negative influence on memory performance for the High exercisers.</p>

<p>Verbal information has predominantly been the to-be-remembered materials in human memory research for more than a century. In recent years some interesting deviations from the established rules of verbal memory have been observed in subjects who have been asked to motorically self-perform (enact) action sentences at the encoding phase of the memory task, instead of only hearing or reading them as in a traditional verbal task (VT). Marked enhancements in recall were also consistently demonstrated in such studies and the effect was named the subject-performed task (SPT) effect. Presently, the body of SPT research is large but little agreement has been reached regarding the mechanism at work in producing the SPT phenomenon. The present thesis addresses two major issues in SPT research. The enhancement of associative information and the significance of the motor component are evaluated. In Study A, the SPT effect was studied in two cued-recall tasks that relied on item-specific association and relational association, respectively. The results showed that SPT encoding interacts with item-specific associative cues at recall to produce a larger SPT effect as compared to free recall. This supports the notion that part of the SPT effect is due to enhanced item-specific association. In Study B, the associative effect in SPT was studied amongst age cohorts comprised of subjects between 40 and 85 years old. Normal age-related decline in episodic memory has elsewhere been suggested to be caused mainly by associative deficits connected with ageing. The results of Study B indicate that the item-specific associative effect in SPT was more age sensitive than recall of VT and the relational associative effect in SPT. In Study C, the question over whether the SPT effect is dependent on motor modality or not was addressed. Self-produced sign language encoding was argued to be qualitatively the same as self-produced oral/verbal encoding, with the motor modality component being the only exception. It was also argued that the motor modality component was the main similarity to performing SPT. Since the signing subjects performed at the same level as the SPT condition at recall, and better than the control conditions (e.g., VT), the conclusion was made that motor activation per se can contribute to memory enhancement in SPT. Whether SPT encoding results in qualitatively different memory traces is discussed as well as the effect of SPT on other types of associative information. The results are also briefly related to other controversies in SPT research. It is concluded, finally, that enactment produces differential effects on different types of associations. The association between verb and noun is clearly enhanced by SPT encoding. Moreover, it is concluded that overt motor activation is necessary for obtaining a full SPT effect. To explore these interactions further and to build upon these conclusions, an increased focus on motor processes and their relation to verbal processes is called for in future cognitive research.</p>

<p>Research on children with Attention Deficit Hyperactivity Disorder (ADHD) has shown that they are extremely sensitive to distraction from external stimuli that lead to poor cognitive performance. This thesis shows that cognitive performance can be improved if this external stimulus is smooth and continuous (e.g. auditory white noise). Control children attenuate their performance under such conditions. The first Study proposes the moderate brain arousal model (MBA). This neurocomputational model predicts selective improvement from noise in ADHD children. Noise through a phenomenon called stochastic resonance (SR), can be beneficial in dopamine deprived neural systems. The statistical phenomenon of SR explains how the signal-to-noise ratio can be improved by noise in neural systems where the passing a threshold is required. The second Study provides experimental support for the MBA-model by showing that ADHD children improve performance in a free recall task while exposed to auditive noise. Control children declines in the same condition. The third Study generalizes this finding among low achieving children, which it is argued have low dopamine levels. Noise exposure improves performance in low achievers, but inhibits performance in high achievers. The conclusion is that external auditory noise can restore low dopamine levels and thus improve cognitive performance. It is also proposed that dopamine levels modulate the SR effect; this means that low dopamine persons require more noise to obtain an SR effect. Both excessive and insufficient dopamine is detrimental for cognitive performance. The MBA model can be used to explain several shortcomings where changes in the dopamine system have been identified. The MBA model can also help create appropriate and adaptive environments, especially in schools, for persons with a deficient dopamine function, such as ADHD children.</p>

<p>Previous findings have suggested that auditive white noise benefits cognitive performance under certain circumstances. The primary purpose of the present pilot study was to explore the effects of visual white noise on verbal episodic memory performance in a normal participant population. Performance was assessed by an immediate free recall test. A secondary purpose was to explore whether participants` eye blink rates and/or temporal processing alters in different noise conditions. The findings of the present study suggest that visual white noise does not affect recall performance among normal participants. However, partially different memory systems and/or memorizing techniques might be used in different noise conditions. Furthermore, noise was not found to affect participants` blink rates or temporal processing.</p>

<p>This thesis examines whether childhood family configuration influences performance on cognitive functions and health in adulthood and old age. All studies examined participants in the Betula Prospective Cohort Study aged 35 to 85 years (Nilsson et al., 1997). Study Ι established whether there are reliable effects of sibship size and birth order in a large sample of participants in adulthood and old age. The results showed that the effects previously demonstrated in children and adolescents (e.g., Belmont & Marolla, 1973; Mercy & Steelman, 1982) have a long-lasting effect and can be demonstrated in an adult sample. These studies concluded that intelligence and executive functioning decreased as the sibship size increased. Birth order, in contrast, had only influenced executive functions and working memory: earlier born siblings performed at a higher level than later born siblings. Study ΙΙ examined whether the effects of sibship size and birth order can be replicated and extended to episodic memory and whether the effects of family configuration are stable over a five-year interval. The results showed that early born siblings and siblings belonging to a smaller sibship size performed at a higher level and that these effects on both recall and recognition were stable over a five-year interval. Study ΙΙΙ explored whether childhood family configuration influences chronic adult diseases (myocardial infarction and circulatory disorders, stroke, and hypertension). The overall results showed that being born in a large sibship is a risk factor for stroke, myocardial infarction /circulatory disorders, and hypertension in old age. The results also suggest that being born early in a sibship is a predictor of stroke.</p>

<p>The general objective of the thesis was to examine aspects of declarative memory functioning across the adult life span. The four papers were based on data collected as part of the Betula Prospective Cohort Study (Nilsson et al., 1997) and included largescale population-based samples of participants in the age range 35 to 90. In study I and study II the possibility that age differences in episodic memory may be compensated for by provision of encoding support in the form of enactment was investigated, using free and cued recall and recognition portioned into components of recollective experience as the dependent measures. In Study III, unitary, two-, and multi-factorial models of declarative memory were compared and age-invariance was tested for. In Study IV cross-sectional age differences were contrasted with five-year longitudinal changes on aggregate measures of episodic and semantic memory within age groups ranging from 35 to 85 years. The results of Study I and Study II demonstrated that enactment constitutes an effective form of encoding support, but that the age differences generalize across this form of encoding support. Study II indicated that most of the age-related variance in recognition and levels of recollective experience following enacted and non-enacted encoding was shared by a measure of processing speed. Study III confirmed that a two-factor model of declarative memory (episodic and semantic memory) yields superior fit as compared with a unitary model of declarative memory. However, the best fitting model was a six-factor model with recall and recognition (episodic memory) and knowledge and fluency (semantic associated with different patterns of age-related differences, with some indications that the first-order factors show differential age-related patterns, indicative of variability that cross-sectional data may give a false impression of decline for adults in the age range 35-60 years for episodic memory. There was no evidence of time-related decline within these age groups, even though practice effects were taken into account. However, past this age, substantial time-related decline was observed for the older adults, in line with cross-sectional data. Semantic memory performance tended to improve across time for the younger groups, but decline in old age, although the magnitude of this decline was less pronounced than for episodic memory. Cohort differences in education may be one important factor underlying the discrepancy between the cross-sectional and longitudinal aging patterns, both in the case of episodic and semantic memory. In conclusion, the result of the present studies show that age-related functional losses occur in forms of declarative memory, especially memory) as first-order factors. Episodic and semantic memory were found to be within the episodic and semantic memory domains. The results of Study IV showed episodic memory, but that the onset of decline does not begin until old age. </p>