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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Self-Esteem, Failure Feedback, and Physiological Reactivity: Implications for Working Memory and Aggression

Ryan, John Patrick 17 July 2009 (has links)
Research has recently begun to focus on separable conscious and subconscious aspects of self-esteem. Meanwhile, research on aggressive behavior has found that some individuals with high self-esteem are more prone to aggressive behavior. Based on a biopsychosocial approach, research has shown that appraisals of threat/challenge are marked by distinct physiological responses – threat appraisals are marked by activation of the hypothalamic-pituitary-adrenal axis, whereas challenge appraisals are marked by activation of the sympathetic adrenal-medullary axis. The present study examines the relationship between failure feedback, implicit and explicit self-esteem, appraisals, working memory and aggression in a series of three experiments. Experiment 1 examined the impact of failure feedback on stress physiology and found that individuals who displayed a physiological response to failure feedback consistent with a challenge response, as indicated by an increase in blood pressure without a concurrent increase in salivary cortisol, were the most likely group to become aggressive. Experiment 2 examined the relationships between implicit and explicit self-esteem in predicting aggressive behavior. Implicit self-esteem predicted behavioral inhibition in response to negative feedback such that higher implicit self-esteem was associated with fewer behavioral inhibition errors. In Experiment 3, threat/challenge motivations were manipulated to determine their impact on working memory performance. Increases in feelings of threat were associated with greater working memory performance, whereas increases in feelings of challenge were associated with decreases in working memory performance. The present study is the first to examine aggression in the context of threat/challenge appraisal responses. Overall, this study suggests that appraisals and physiology can assist in predicting aggressive behavior, although the cognitive mechanism by which this occurs remains elusive.
182

Räkna - Läsa - Minnas : Vilka samband finns det? / Calculate – Read – Remember : What correlation is there?

Thompson, Helen, Petersson, Yvonne January 2011 (has links)
Syftet med studien är att undersöka samband som visas tydligt hos elever i både matematiksvårigheter samt fonologiska svårigheter. Studien har genomförts på elever i årskurs 7 som uppvisat matematiska såväl som fonologiska svårigheter. Resultatet baseras på en filmad observation där eleverna fått lösa ett urval uppgifter konstruerade utifrån svårigheter gällande grundläggande taluppfattning och aritmetik. Elever med fonologiska svårigheter såväl som bristande arbetsminne visar sig ha svårigheter när det gäller att automatisera tabellkunskap såväl som utföra beräkningar gällande de fyra räknesätten. / The purpose of the study is to research what correlation is apparent in students with both mathematical and phonological difficulties. The study has been conducted with 7th grade students who have shown both mathematical and phonological difficulties. The result is based on a filmed observation where the students solved a selection of tasks constructed based on problems with basic number sense and arithmetic. Students with phonological difficulties as well as inadequate working memory are showing problems when it comes to automated knowledge of the multiplication table as well as performing calculations concerning arithmetic.
183

Investigating Spatial Working Memory and Saccadic Remapping Processes in Healthy Young and Elderly Participants

Goldberg, Lana January 2009 (has links)
Additional cognitive deficits, including impairments in spatial working memory and/or saccadic remapping processes, have recently been implicated in unilateral neglect – a neurological condition classically characterized as a disorder of attention. The interactions between saccadic remapping and three memory processes (position memory, object memory and object-location binding) were investigated in healthy young (n=27) and elderly (n=20) participants to establish a baseline of comparison for future use with neglect patients and to study the effects of aging on these processes. In a computerized task, participants were instructed to first detect a target, and then hold in memory either its position, identity or both over a delay period. Subsequently, participants were tested on their memory for that particular task. The saccadic remapping component was introduced at the onset of the delay period with the fixation cross shifting either to the left, or right, requiring participants to remap the visual array into either right or left space, or remaining in the centre of the screen (i.e., no remapping condition). In the position memory and object-location binding task, a consistent cost to memory performance was found when remapping right only for the young participants. Overall the elderly did not perform any of the tasks involving a position memory component as well as the young participants and showed spatial asymmetries in the target detection task. The lack of an effect of remapping in the elderly group may be due to a general decrement in performance. These results are discussed in terms of hemispheric asymmetries and cognitive theories of aging.
184

The effects of gaming on working memory, inattention, reading and math : A longitudinal study

Sjöwall, Douglas January 2010 (has links)
Previous research has shown both positive and negative effects of gaming on academic and cognitive performance. The purpose of this study was to assess the effect of gaming on development of working memory (WM), inattention, reading and math ability using a longitudinal design. A randomly chosen sample of 335 (168 girls) 6–25 year olds performed tests of visuo-spatial and verbal WM, reading and math ability twice, with a two year interval. Gaming and inattention were assed with questionnaires. Time spent gaming did not affect development of any of the variables. However, game category did correlate with development of visuo-spatial WM, with action-gamers having a more favourable development. There was, however, no positive interaction with more time spent gaming for action-gamers. These results suggest that gaming should not be regarded as a damaging leisure activity. There could instead be some positive effects of gaming, but future research should try to identify the aspects of gaming contributing to this effect.
185

Testing executive function models of ADHD and its comorbid conditions: A latent variable approach

Lee, Dong Hyung 01 November 2005 (has links)
Current theoretical models of ADHD (i.e., Disinhibition Model: Barkley, 1997; Working Memory Model: Rapport et al., 2001) conceptualize ADHD as the disorder of executive function (EF) with some variation in their emphases on particular components of the broadly-defined EF (e.g., working memory vs. inhibition) and in their postulated relationships with ADHD symptoms. Although these models provide systematic accounts of the manifestation of ADHD, they have not been extensively tested from an empirical standpoint. Moreover, despite the fact that ADHD is highly comorbid with other additional conditions such as learning and behavioral problems and EF deficits are found in individuals with these conditions as well as in those with ADHD, current EF models have not specified the developmental relationship between ADHD and its comorbid conditions. This study was: (1) to examine the extent to which two current models of ADHD are supported in a sample of 102 adults; (2) to present an ??integrated?? model by combining two current models of ADHD and linking them to recent research findings on two common comorbid conditions with ADHD (i.e., reading difficulty and substance abuse); and (3) to test and revise such an integrated model in the light of data using a latent variable analysis. Major findings provided a strong support for the Working Memory Model with a lesser degree of support for the Disinhibition Model. Preliminary evidence of working memory as the primary deficit in ADHD was also obtained in the present sample. Finally, the integrated EF model and its revised model (final model) demonstrated a very good fit to the data. These findings suggest that the integrated model provides a unified account of how EF deficits contribute to the manifestation of ADHD symptoms and comorbid conditions with ADHD. Given some limitations (e.g., sample size and scope) of the present study, current findings need to be replicated.
186

Executive function processes: inhibition, working memory, planning and attention in children and youth with Attention Deficit Hyperactivity Disorder

Wolfe, Monica Eileen 12 April 2006 (has links)
This study examines the roles of inhibition, attention, working memory, and planning in youth with and without ADHD. As conceptualized in theories of attention, inhibition, and working memory, difficulties with these executive processes interact to manifest in the behavioral syndrome(s) of ADHD. Barkley (1997) proposed disinhibition as the primary deficit of ADHD. Rapport, Chung, Shore, Denney, & Isaacs, (2000) theorized that ADHD results from a primary deficit in working memory. Mirsky (1987) proposed a model of attention which children with ADHD have deficits in abilities to focus/execute, encode and sustain attention. Posner and Petersen (1990) proposed that three attentional networks are responsible for attentional processes and those children with ADHD have deficits in the vigilance network. To investigate the contributions of inhibition, working memory, attention, and planning in executive dysfunction in children with ADHD, measures were selected from factor analytic studies. Children with ADHD-Combined Type demonstrated poorer inhibition and working memory than children with no diagnosis after controlling for IQ effects. No differences in planning and attention were indicated after controlling for IQ effects. However, a predictive discriminant analysis indicated that none of the executive processes contributed to the prediction of group membership. Given correlational and predictive discriminant analysis results, further analyses were conducted to investigate the contribution of the measures selected for the domains. The theoretical model did not represent a good fit of the data. A three-factor model indicated the best representation suggesting that inhibition and attention were not separable. There were no group differences with the revised measurement model for inhibition/attention, working memory and planning. Taken together, results indicated measures originally selected to tap executive function may not be clean measures of inhibition, working memory, planning, or attention processes. In addition, recently proposed theories overlap and conceptualize the multiple constructs involved in ADHD with a variety of methodologies, further contributing to difficulties in interpreting results and measurement issues.
187

Carry-Over Facilitation for Non-Familiar Trials in Item-Recognition

Engström, Lisa January 2010 (has links)
<p>Two aspects of cognitive control were investigated using the item-recognition task and the verb generation task. The item-recognition task had two conditions, high and low interference. The verb generation task was manipulated in three ways, for different levels of interference and time interval. The intention was to more deeply investigate one aspect of the item-recognition task, comparing response times for different trial types in different conditions, and to investigate a fatigue effect between the item-recognition and verb generation task. Thirty-two participants were tested at two occasions, in a within-subjects design. Results for the verb generation task revealed effects for levels of interference and time interval, although there was no difference in the manipulation. Results for the item-recognition task revealed effects for condition and trial type, as well as an interaction effect between these. The non-familiar trials in the high interference condition resulted in faster response times compared to the same kind of trials in the low condition. The result from the item-recognition task extends those from previous studies, revealing details for differences between trial types. This finding demonstrates a carry-over facilitation effect.</p>
188

Does time perception underlie delay discounting?

Berman, Rachel Elisabeth 18 October 2013 (has links)
Delay discounting, the belief that rewards decline in value over time, is a phenomenon observed in several clinical disorders, including Attention Deficit / Hyperactivity Disorder (ADHD), substance abuse disorders, and other impulse control disorders. Delay discounting behavior is characterized by a tendency to choose smaller, more immediate rewards over larger, more delayed rewards. This tendency has been associated with behavioral impulsivity and inability to delay gratification observed in the aforementioned clinical disorders. It has been suggested that time perception may be a salient feature of delay discounting. If the larger, longer-term reward is perceived as being more temporally remote, its relative value decreases and is associated with greater cost, and one becomes more likely to choose the more immediate reward over the longer-term (though optimal) choice. Time perception has been studied in clinical populations, with increased variability of responses as well as both under-production and overestimation of time intervals observed in those with ADHD and other disorders associated with impulsivity. The present study used informational feedback via a metronome to change belief regarding duration of a second--either increasing or decreasing it by approximately 20%. Participants were 132 college-aged students with and without a diagnosis of ADHD. Measures of impulsivity and ADHD symptomatology were collected as well, and participants completed several cognitive tasks measuring working memory and processing speed to explore the impacts of these measures on delay discounting and time perception. While participants were able to reliably incorporate the altered second belief into short estimations of time (i.e., less than a minute), the manipulation failed to generalize to longer-duration temporal estimations, and it did not affect delay discounting. Neither ADHD symptomatology, impulsivity, nor performance on the cognitive tasks were related to delay discounting behaviors, though a working memory measure was correlated with baseline (pre-manipulation) time and one longer duration estimation. This lends support to a relationship between working memory and temporal perception, though the relationship between temporal perception and delay discounting remains elusive. Directions for future studies to clarify the role of temporal processing and ADHD in delay discounting are discussed. / text
189

Exploring the Relationships Between Children's Working Memory and Long-Term Memory

2015 November 1900 (has links)
Working memory and long-term memory are two types of memory associated with children’s learning and academic performance. A number of memory models have suggested there is a relationship between working memory and long-term memory; however, there is a lack of empirical research measuring this relationship using standardized assessment tools. Further, there are currently no studies measuring this relationship in children. The purpose of this study was to investigate the relationship between children’s working memory (i.e., verbal working memory, visual-spatial working memory, verbal short-term memory, visual-spatial short-term memory, and the central executive) and long-term memory, using standardized assessment tools. The Automated Working Memory Assessment was used to measure working memory and the Woodcock-Johnson Tests of Cognitive Abilities – Third Edition was used to measure long-term memory. This study utilized secondary data from a larger SSHRC funded study. Participants included 41 children between grades 1 and 8. The majority of parents who volunteered to have their children participate identified them as having a disability (e.g., speech/language difficulty; learning disability). Kendall’s tau-b revealed statistically significant correlations between four areas of working memory (i.e., verbal working memory, visual-spatial working memory, visual-spatial short-term memory, and central executive) and long-term memory. Mann-Whitney tests revealed children with higher working memory abilities differed significantly from children with lower working memory abilities on measures of long-term memory. The findings from this study may have implications for both theory and practice. The relationship observed between working memory and long-term memory appears to align with widely accepted memory models (e.g., Baddeley, 2000; Dehn, 2008). The findings also suggest interventions designed to improve children’s working memory may have the potential to enhance long-term memory abilities.
190

Measuring, monitoring, and maintaining memories in a partially observable mind

Suchow, Jordan William 06 June 2014 (has links)
Visual memory holds in mind details of objects, textures, faces, and scenes. After initial exposure to an image, however, visual memories rapidly degrade because they are transferred from iconic memory, a high-capacity sensory buffer, to working memory, a low-capacity maintenance system. How does visual memory maintenance work? This dissertation builds the argument that the maintenance of short-term visual memories is analogous to the act of breathing: it is a dynamic process with a default behavior that explains much of its usual workings, but which can be observed, overridden, and controlled. Chapter 1 shows how the act of trying to remember more information causes people to forget faster and to remember less ("load-dependent forgetting" and "overreaching"). It then shows how the paradigm of evolution can be applied to the problem of maintenance, with memories competing over a limited memory-supporting commodity, explaining these effects. Chapter 2 presents experiments on metamemory, the ability of people to observe and make decisions about their own memories. The experiments isolate a component of metamemory that monitors a memory's quality as it degrades over time. Chapter 3 connects memory to metamemory, drawing on work from reinforcement learning and decision theory to liken the problem of memory maintenance to that of an agent who sequentially decides what to prioritize in a partially observable mind. / Psychology

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