• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 185
  • 93
  • 27
  • 26
  • 11
  • 4
  • 4
  • 4
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 447
  • 447
  • 108
  • 88
  • 84
  • 81
  • 67
  • 53
  • 44
  • 39
  • 39
  • 37
  • 35
  • 33
  • 33
  • 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.
51

Affect, cognition, awareness and behavior in eating disorders : comparison between obesity and anorexia nervosa

Cserjesi, Renata 03 July 2008 (has links)
Introduction: Eating is a highly motivated and reinforced behaviour, therefore human eating behaviour is not a passive response or merely physiological drives providing nutrients for survival; it is about cognitive and emotional processes based choice. Obesity is a condition in which the natural energy reserve, stored in the fatty tissue of humans is increased to a point where it is associated with certain health conditions or increased mortality. Anorexia nervosa is a condition of self initiated weight loss characterised by a profound disturbance of the body image, distorted self-perception, and obsessive fear of gaining weight and problem in the cognitive and the emotional functioning. Continuum model proposed that eating disorders from restriction to overeating can be placed on a linear dimension. Aim: The main goal of the doctorate thesis is to examine the existence of certain common dysfunction related to the two extreme sides of the dimension of the eating disorders (restrictive anorexia and stable obesity). Therefore we compared cognitive profile, emotion functioning (explicit and early categorization of facial emotions) and attitudes (explicit and implicit) towards body image both in obesity and anorexia. Results: The neuropsychological tasks show attentional deficit and distractibility in obesity and anorexia nervosa. In obesity we have found perseveration, deficit on the shifting and inhibition capacity, while in anorexia nervosa perseveration was linked to anxiety. These findings suggest that the PFC based executive function can be associated with modified brain dopamine turnover in the PFC area in obesity. Beside, the higher level of depression in both patient groups; our findings proved that obese patients were more sensitive to the positive emotions and the same time they ignored the negative emotions. In contrary to obesity, anorexic patients were more sensitive to negative emotions specifically those one which represent possible threats such as anger. Obese patients evaluated implicitly more positive the overweight body figures than controls. There was an attitudinal discrepancy between the explicit, socially exposed “ideal body” and the internal (implicit) body shape preference. The anorexic group did not evaluate positively the underweight body shape as we expected either implicitly or explicitly. Based on these findings we suggest that not the underweight body preference is a key issue in anorexia, but the obsessive fear for the obesity. Conclusion: We have found different psychological mechanisms in the pathology of restrictive anorexia nervosa and stable obesity. Our results did not confirm the idea of the continuum model about the linear spectrum based on eating behaviour (from the restriction to overeating), and from body weight (from underweight to obese). Our results suggest that restrictive anorexia nervosa has several common features with anxiety disorder or affective disorders, while obesity most probably can be associated with addictive pathologies.
52

Working Memory and Higher-Order Cognition in Children

Tillman, Carin January 2008 (has links)
<p>Higher-order cognitive functions, such as executive function (EF) and intelligence, are crucial to the everyday functioning of human beings. Gaining knowledge about these functions is important for our general understanding of human nature as well as for our ability to help those who may not develop these processes optimally. The present thesis focused particularly on the EF component working memory (WM), described as the ability to maintain informa-tion in consciousness during short time periods with the purpose of using that information in complex cognition. The major aims of the thesis were to increase our understanding of higher-order cognition in children as well as of deficiencies in intelligence found in children with Attention Deficit Hyperactivity Disorder (ADHD). We approached these aims by studying the interrelations among EF-related components in terms of their independent contributions to intellectual functioning. We also studied whether the lower intelligence in children with ADHD was mediated by fundamental EF-related components or whether these deficiencies went beyond the weaknesses in these specific cognitive functions.</p><p>Interpreting the present data, we suggest that intellectual functioning in children is best viewed as representing a system of primarily independent parts that may be accompanied by an overarching common mechanism. The multiple components involve, but are surely not limited to, WM functions, inhibitory functions, sustained attention, and processing speed. One of these functions, WM, was found to be further partitioned into domain-specific executive WM processes and domain-specific short-term storage processes, all of which constitute important aspects of higher-order cognitive functioning. We have further learned that deficits in fluid intelligence in children with ADHD may entail more than weaknesses in specific central cognitive functions. This additional deficit is cautiously interpreted as involving supe-rior executive attention functions setting the stage for the development and integration of the EF system as well as the “intelligence system”.</p>
53

Does the language of children born less than 28-weeks gestation differ from language-age matched pairs?

Phillips, Mary E January 2006 (has links)
In New Zealand, approximately 10% of births are considered premature, that is less than 37 weeks gestation. With advances in medical technology, young infants are surviving gestation periods as few as 23 weeks. It is expected that many of these severely premature infants will demonstrate some problem in their academic, or cognitive function including language functioning. It is agreed that children who are born severely premature often present with language problems, the nature of the difficulties are not clear. Research examining language abilities that involve cognitive functions such as inference generation have demonstrated that children born prematurely exhibit difficulties with phonologic short-term memory and executive function. Language tasks such as inference understanding require children to integrate real-world knowledge with the linguistic information to generate and produce language that is more complex. The aim of this study was to discover if the language of children born severely premature differs from that of language-age matched peers. This study examined high-level language abilities of school-age children born severely prematurely, specifically, language tasks that involved executive functions including working memory, story inferencing, and recognising absurdities. Six children who were born less than 28 weeks gestation participated in this study. Their results on the above measures were compared to a language-aged matched comparison group, determined by performance on a standardised test. It was hypothesised that the children born severely premature would not differ from their language-age matched peers on measures of general language ability but differences would exist on measures of language processing and inferencing. The findings overall showed little difference between the preterm group and their language-age matched peers on measures except for the measure of chronological age. Although no group difference was found for the measure of working memory, a larger variance on this measure was observed in the preterm group.
54

Executive Function at Early School Age in Children Born Very Preterm

Clark, Caron January 2008 (has links)
Impairments in executive function have been posited to account for some of the poor cognitive and educational outcomes associated with very preterm birth. As part of a prospective, longitudinal study, this research examined executive function in a regionally representative sample of 103 children born very preterm and/or very low birth weight (<33 weeks GA / <1500g) and a comparison sample of 108 full term children at age 6 years (corrected for prematurity). The specific aims of the study were 1) to describe the performance of children born very preterm and full term on a range of executive function measures, 2) to identify the antecedent medical, neurological and socio-familial factors associated with executive function performance within the very preterm group, and 3) to examine linkages between children’s executive function performance and their academic achievement at age 6 years. Children underwent a comprehensive developmental assessment, including standardised tests of IQ and academic achievement in mathematics, reading and receptive language. Additionally, they completed a number of executive function tasks selected to assess verbal working memory (Digit Span), spatial working memory (Corsi Blocks), planning and problem-solving (Tower of Hanoi), selective attention (Visual Search), shifting and inhibitory control (Detour Reaching Box) and sustained attention and inhibition (Kiddie-Conner’s Continuous Performance Task; K-CPT). Parents and teachers of these children also completed the Behavioural Rating Inventory of Executive Function and teachers rated children’s performance in reading, arithmetic and comprehension in relation to their classroom peers. Results revealed a pervasive pattern of impairment across multiple measures of executive function in children born very preterm relative to their full term peers. Specifically, children born very preterm were less likely to be able to complete any backward Digit Span trials (p<0.05) and showed lower raw scores on this task (p<0.1) than children in the full term group. Children born very preterm showed lower spatial span scores on the Corsi Blocks Task (p<0.01). They also showed lower planning performance, as assessed by the Tower of Hanoi (p<0.05). Children born very preterm made more inhibitory control/shift errors on the Detour Reaching Box and demonstrated less accuracy in their Visual Search (p<0.001) than children born full term. Finally, they showed lower levels of sustained attention on the K-CPT (p<0.001). Parents, teachers and examiners rated these children as having greater difficulties across multiple areas of executive function. These differences remained significant after controlling for group differences in socioeconomic status and after exclusion of children with severe cognitive and motor impairments. Within the very preterm group, antecedent predictors of poorer working memory and planning performance included male gender (p<0.001), intrauterine infection (p<0.05) and severity of cerebral white matter abnormality on term-equivalent MRI (p<0.05). Lower gestational age (p<0.05) and male gender (p<0.001) were related to poorer executive attention performance. Familial predictors of poorer executive performance included instability in parenting (p<0.05), higher levels of parental intrusiveness (p<0.1) and lower levels of interactional synchrony (p<0.05) between parent and child, recorded at earlier follow-up points. Finally, children’s executive function performance was highly correlated with school achievement in reading, arithmetic and language comprehension (p<0.001). Findings suggest a global pattern of executive impairment amongst children born very preterm, with these difficulties placing children at risk for poor academic performance and learning difficulties. Findings also suggest that both neurological pathology and early parenting experiences are important mediators of the relationship between very preterm birth and poor executive function, highlighting the importance of these areas for early intervention.
55

Protective effects of peri-menopausal oestrogen replacement : a test of the critical period hypothesis

Pettit, Sophie Anastasia Rebecca January 2013 (has links)
Oestrogen decline during the menopause leads to decline in cognitive performance because oestrogen receptor sites are found in the prefrontal cortex and hippocampus of the female brain, areas associated with memory and attention functions. Extensive research over the past two decades has tested the effects of administering Hormone Replacement Therapy (HRT) to maintain oestrogen levels. MRI studies have shown improvements in hippocampal volume and frontal functions with HRT, but evidence for associated improvements in verbal memory performance has been mixed. Some studies have even found detrimental effects of HRT, leading to the suggestion of a critical period for HRT administration relative to menopause. Oestrogen receptor sites are found in frontal brain regions associated with working memory (WM) functions including attention. These functions have been researched less than verbal memory, but with similarly mixed findings. The research reported in this thesis tested the critical period hypothesis in relation to WM. Study one tested the prediction that HRT will benefit WM if the therapy is initiated during the peri-menopause, and will harm it if initiated post-menopause. A naturalistic sample of 121 women were recruited, comprising women who varied in the time they had begun taking HRT, and menopausal status-matched controls who had never taken HRT. Participants completed three tests of WM span and the Sustained Attention to Response Task (SART) on two occasions 12 months apart. WM performance supported the critical period hypothesis, with women who had begun the therapy after the menopause displayed worsened WM capacity when compared to peri-menopausal initiators and post-menopausal women with no history of HRT use. At one year follow up, postmenopausal HRT users were still underperforming compared to peri-HRT initiators and those in the post-menopausal stage with no history of HRT use. No significant differences were identified between groups on the SART. The effects of natural supplements on physical symptoms of the menopause have been researched, but there is little research on their effects on cognitive symptoms and none specifically testing the critical period hypothesis. Study two tested the effects of soya isoflavones on WM during peri- and post-menopausal stages. One hundred and twelve peri- and post-menopausal women were randomly allocated to receive either placebo or 100mg soya supplement in capsules daily for three months. Participants and researcher were blind to this allocation. Participants completed two tests of WM span and two Sustained Attention (SA) tasks at baseline, after three months of soya/placebo, and after a further three months without supplement. There was no effect of isoflavones on cognition, regardless of time of initiation of the supplement. This thesis offers a unique contribution to the literature, by establishing empirically that HRT may have long-lasting benefits for WM if administered in the peri-menopause period, and detriments if taken post-menopause. There was no evidence that administration of soya-based phytoestrogens for three months peri- or post-menopause replicated these effects of HRT on cognition.
56

Two-Generation Approach to Improving Emotional and Behavioral Regulation:

Longo, Francesca January 2017 (has links)
Thesis advisor: Eric Dearing / Increasing evidence indicates that exposure to poverty in early childhood may undermine neural growth that is critical to developing executive functions (EF) and, in turn, emotional and behavioral regulation (Blair et al. 2011; Kim et al., 2013; Raver et al., 2013). There is, however, also increasing evidence indicating that high-quality Early Childhood Education (ECE) (a) buffers children from risks associated with early exposure to poverty and (b) supports healthy socio-emotional development (Bierman et al., 2008; Raver, 2002; Yoshikawa et al., 2013). One line of this intervention work has focused on two-generation programs that pair high-quality ECE with supports for parents that are designed to improve parenting and the home environment. Although evidence on two-generation programs is mixed (Grindal et al., 2016; Neville et al., 2013), it is clear that much of the risk of poverty is relayed to children through their homes, and parenting is among the most critical influences on child emotional and behavioral self-regulation in infancy and early childhood (Bradley & Corwyn, 2004; Calkins & Johnson, 1998; Calkins et al., 1998). The present study builds on existing theoretical and empirical prior work indicating that children’s EF skills are important precursors to emotional and behavioral regulation that may be best promoted when addressed in both classroom and home contexts. Specifically, the present study uses a randomized design to evaluate the effects of classroom-based activities that target children’s executive functioning and the value added by training parents to better support their children’s EFs. Children were evaluated pre- and post-intervention on EF skills and prosocial and adaptive problem-solving behavior. In general, few significant effects of either the child training or the added parent component were evident. These findings are discussed with special attention to the fact that fidelity of implementation of the classroom and parent trainings was low, with less than half of teachers incorporating games at least once a week and only 13 percent of parents attending the trainings. In addition, implications for future empirical work as well as policy and practice are discussed with special attention given to further inquiry into the malleability of EF. / Thesis (PhD) — Boston College, 2017. / Submitted to: Boston College. Lynch School of Education. / Discipline: Counseling, Developmental and Educational Psychology.
57

Developing and evaluating the feasibility of an active training game for smart-phones as a tool for promoting executive function in children

Gray, Stuart Iain January 2017 (has links)
Executive function (EF) comprises a series of interrelated cognitive and self-regulatory skills which are required in nearly every facet of everyday life, particularly in novel circumstances. EF skills begin developing from birth and continue to grow well into adulthood but are most crucial for children as they are associated with academic and life success as well as mental and physical health. There is now strong evidence that these skills can be trained through targeted intervention in a diverse range of approaches, such as computer games, physical activity, and social play settings. This thesis presents the process of the design and evaluation of an active EF-training game (BrainQuest) for smart-phones, in participation with end-users: a group of 11-12-year-old children from a local Primary School. The design process placed emphasis on creating an engaging user experience, a phenomenon which has eluded many serious games, by building upon motivational game design theory and satisfying end-user requirements. However, in the pursuit of promoting particular executive functions: working memory; inhibitory control; planning and strategizing, the design integrated aspects of a cognitive assessment while also utilizing a range of alternative approaches for training EF, including physical activity and social play. Following an iterative design process which included many single session prototype evaluations, a mixed methods evaluation was undertaken during a 5-week study with twenty-eight 11-12-year-old school children. The study gathered exploratory qualitative and quantitative evidence regarding the game’s potential benefits which was evaluated by triangulating a range of data sources: multi-observer observations notes, interviews with children and teachers, game performance data and logs, and cognitive assessment outcomes. The analysis describes the statistical relationships between game and executive function ability, before exploring user experiences and evidence of cognitive challenge during gameplay through a series of triangulated case studies and general whole-class observations. The analysis presents the game to be engaging and enjoyable throughout the study and, for most children, able to generate a sustainable challenge. Though there were initial difficulties in understanding the complex game rules and technology, the game became increasingly usable and learnable for the target user group and created opportunities for goal setting. It also encouraged feelings of pride and self-confidence as well as facilitating positive social interactions and requiring regulation of emotion, which are considered to be pathways to developing executive functions (Diamond, 2012). There was also promising initial evidence that the game’s variable difficulty level system was able to challenge executive functions: planning and strategizing, working memory, and inhibitory control. Most notably, the game appeared to support improvements in strategizing ability by demanding increasing strategic complexity in response to evolving and increasingly difficult task demands. Supporting BrainQuest’s cognitive challenge, several statistical relationships emerged between executive function ability and game performance measures. However, the game’s ability to significantly improve cognitive outcomes could not yet be concluded. Nevertheless, these findings have implications for both the future design and evaluation practices undertaken by cognitive training researchers. From a design perspective, less credence should be paid to simply gamifying cognitive assessments while greater emphasis should be placed on integration of formal game design and motivational theories. With regards to evaluation, researchers should understand the importance of establishing first whether CTGs can remain engaging over time as well as the feasibility of their challenge to cognitive functions.
58

The role of counterfactual thinking in deceptive communication

Briazu, Raluca Andra January 2018 (has links)
This thesis explores the proposal that there is a close link between counterfactual thinking and lying. Although both require the imagination of alternatives to reality, research has yet to establish a direct link. In the first seven studies the relationship between counterfactuals and lies is directly investigated using novel scenario-based and behavioural tasks. In a further four studies we also investigate the role of affect and executive functions as explanatory mechanisms. Results show that individuals with a tendency to think counterfactually are more likely to generate potential lies and to be more successful when lying in front of others (Study 1 and 6). Furthermore, we also show that counterfactual availability influences people’s tendency to come up with lies (Studies 2, and 3) and the extent to which they expect others to lie (Studies 4, and 5). We also find that the saliency of counterfactual alternatives can affect people’s moral standards by motivating them to lie (Study 7). Based on these results we argue that counterfactuals motivate lying by providing information about how things could have been different. We however also investigate alternative explanations. In Studies 8, 9 and 10 we seek to understand whether counterfactually derived affect might also underlie the relationship, but find no such link. Additionally, in Study 11 we investigate the relationship in Parkinson’s disease participants in order to understand if executive function might be an underlying mechanism. We do not find this to be the case and we show that PD patients are able to engage in counterfactual thinking and also lie. The findings in this thesis are the first to provide a direct link between counterfactual thoughts and lies. Overall, we show how counterfactuals can help us mislead others and we reveal that counterfactual thinking is an important cognitive process in deception.
59

Investigating to What Degree Individual Differences in Language and Executive Function Are Related to Analogical Learning in Young Children Across Socio-Economic Populations

O'Neil, Lauren 30 April 2019 (has links)
Analogical reasoning is a foundational skill necessary for enabling learners to draw inferences about new experiences, to transfer learning across contexts, and to make abstractions based on relevant information from daily experiences. Linguistic and executive function (EF) skills may support analogical reasoning ability, as both these skill sets have previously been shown to influence other higher-order cognitive abilities, such as perspective taking. Outside influences such as socio-economic status (SES) backgrounds may also influence analogical reasoning, as they have been shown to affect other cognitive processes. At present, current research offers little information about developmental relations among SES, language, EF and analogical learning. The purpose of this dissertation research was to explore the extent to which the provision of relational language facilitates children’s analogical reasoning, and to investigate the influence of SES, executive function and language skills in regard to such facilitation. Results indicate that the use of relational language indeed aids analogical reasoning. SES significantly predicted analogical reasoning, but interestingly, this was so only when relational language was absent. These findings support that relational language plays a key role in scaffolding analogical reasoning, and this support is particularly beneficial to children whose cognitive skills may be influenced by SES.
60

An exploration of repetitive negative thinking, executive functions and depressive symptoms

Stephens, Claire January 2017 (has links)
Research is increasingly attempting to understand the developmental nature of depressive symptomology and its links with executive functioning (EF), repetitive negative thinking (RNT) and stress (e.g., Snyder & Hankin, 2016). Prospective studies are needed to explore the potential mechanisms underlying these associations. This study investigated whether EFs can predict changes in RNT, stress and depressive symptoms during a period of stress. One hundred and two undergraduates completed questionnaires measuring life events, trait and state RNT, depressive and anxious symptoms as well as behavioural EF tasks of cognitive switching and inhibitory control at baseline (Time 1). Follow-up questionnaires of RNT, stress, depression and anxiety were gathered approximately two months later (Time 2), during students’ formal examinations, a period of naturally elevated stress. Findings indicated no association between EF and RNT, depression or anxiety but found that the interaction between high levels of trait RNT and low levels of EF (switching) at baseline was a significant predictor of change in state RNT under stress. Findings are discussed in light of current research attempting to unpick associations between EF, RNT and depression in young adults.

Page generated in 0.0966 seconds