Lic.-avh. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2008. / Härtill 2 uppsatser.

It is far from conclusive what distinguishes the inattentive (ADD) and the combined (ADHD-C) subtype of ADHD on the neuronal level. Theoretical considerations suggest that especially interval timing processes may dissociate these subtypes from each other. Combining high-density EEG recordings with source localization analyses, we examine whether there are ADHD-subtype specific modulations of neurophysiological processes subserving interval timing in matched groups of ADD (n = 16), ADHD-C (n = 16) and controls (n = 16). Patients with ADD and ADHD-C show deficits in interval timing, which was correlated with the degree of inattention in ADD patients. Compared to healthy controls, patients with ADHD-C display a somewhat weaker, yet consistent response preparation process (contingent negative variation, CNV). In patients with ADD, the early CNV is interrupted, indicating an oscillatory disruption of the interval timing process. This is associated with activations in the supplemental motor areas and the middle frontal gyrus. Patients with ADD display adequate feedback learning mechanisms (feedback-related negativity, FRN), which is not the case in patients with ADHD-C. The results suggest that altered pacemaker-accumulation processes in medial frontal structures distinguish the ADD from the ADHD-C subtype. Particularly in patients with ADD phasic interruptions of preparatory neurophysiological processes are evident, making this a possible diagnostic feature.

The aim of diploma thesis was to summarize the theoretical knowledge of working satisfaction and factors which influence the working satisfaction of employees. After that, this theoretical level was transferred to practical parts of thesis. On the basis of results which were found out from research were suggested improvement measures. In this research was used a method of questionnaire survey and discussion with the top management. The top management could change and adjust the questionnaire. The research was filled out by all employees, except of company executives. The questionnaire was focused on factors of satisfaction that are related to the content of work, remuneration, the atmosphere in the workplace, working conditions and environment, executives managers, relationship to company and personal development. At the conclusion was followed by question as why the employee remain in the company and what are the reasons of leaving.

Altered emotion processing and regulation mechanisms play a key role in eating disorders. We recently reported increased fMRI responses in brain regions involved in emotion processing (amygdala, dorsolateral prefrontal cortex) in acutely underweight anorexia nervosa (AN) patients while passively viewing negatively valenced images. We also showed that patients’ ability to downregulate activity elicited by positively valenced pictures in a brain region involved in reward processing (ventral striatum) was predictive of worse outcomes (increased rumination and negative affect). The current study tries to answer the question of whether these alterations are only state effects associated with undernutrition or whether they constitute a trait characteristic of the disorder that persists after recovery. Forty-one individuals that were weight-recovered from AN (recAN) and 41 age-matched healthy controls (HC) completed an established emotion regulation paradigm using negatively and positively valenced visual stimuli. We assessed behavioral (arousal) and fMRI measures (activity in the amygdala, ventral striatum, and dorsolateral prefrontal cortex) during emotion processing and regulation. Additionally, measures of disorder-relevant rumination and affect were collected several times daily for 2 weeks after scanning via ecological momentary assessment. In contrast to our previous findings in acute AN patients, recAN showed no significant alterations either on a behavioral or neural level. Further, there were no associations between fMRI responses and post-scan momentary measures of rumination and affect. Together, these results suggest that neural responses to emotionally valenced stimuli as well as relationships with everyday rumination and affect likely reflect state-related alterations in AN that improve following successful weight-recovery.

Goal-directed actions frequently require a balance between antagonistic processes (e.g., executing and inhibiting a response), often showing an interdependency concerning what constitutes goal-directed behavior. While an inter-dependency of antagonistic actions is well described at a behavioral level, a possible inter-dependency of underlying processes at a neuronal level is still enigmatic. However, if there is an interdependency, it should be possible to predict the neurophysiological processes underlying inhibitory control based on the neural processes underlying speeded automatic responses. Based on that rationale, we applied artificial intelligence and source localization methods to human EEG recordings from N = 255 participants undergoing a response inhibition experiment (Go/Nogo task). We show that the amplitude and timing of scalp potentials and their functional neuroanatomical sources during inhibitory control can be inferred by conditional generative adversarial networks (cGANs) using neurophysiological data recorded during response execution. We provide insights into possible limitations in the use of cGANs to delineate the interdependency of antagonistic actions on a neurophysiological level. Nevertheless, artificial intelligence methods can provide information about interdependencies between opposing cognitive processes on a neurophysiological level with relevance for cognitive theory.

A multitude of sensory inputs needs to be processed during sensorimotor integration. A crucial factor for detecting relevant information is its complexity, since information content can be conflicting at a perceptual level. This may be central to executive control processes, such as response inhibition. This EEG study aims to investigate the system neurophysiological mechanisms behind effects of perceptual conflict on response inhibition. We systematically modulated perceptual conflict by integrating a Global-local task with a Go/Nogo paradigm. The results show that conflicting perceptual information, in comparison to non-conflicting perceptual information, impairs response inhibition performance. This effect was evident regardless of whether the relevant information for response inhibition is displayed on the global, or local perceptual level. The neurophysiological data suggests that early perceptual/ attentional processing stages do not underlie these modulations. Rather, processes at the response selection level (P3), play a role in changed response inhibition performance. This conflict-related impairment of inhibitory processes is associated with activation differences in (inferior) parietal areas (BA7 and BA40) and not as commonly found in the medial prefrontal areas. This suggests that various functional neuroanatomical structures may mediate response inhibition and that the functional neuroanatomical structures involved depend on the complexity of sensory integration processes.

Executive functions, like the capacity to control and organize thoughts and behavior, develop from childhood to young adulthood. Although task switching and working memory processes are known to undergo strong developmental changes from childhood to adulthood, it is currently unknown how task switching processes are modulated between childhood and adulthood given that working memory processes are central to task switching. The aim of the current study is therefore to examine this question using a combined cue- and memory-based task switching paradigm in children (N = 25) and young adults (N = 25) in combination with neurophysiological (EEG) methods. We obtained an unexpected paradoxical effect suggesting that memory-based task switching is better in late childhood than in young adulthood. No group differences were observed in cue-based task switching. The neurophysiological data suggest that this effect is not due to altered attentional selection (P1, N1) or processes related to the updating, organization, and implementation of the new task-set (P3). Instead, alterations were found in the resolution of task-set conflict and the selection of an appropriate response (N2) when a task has to be switched. Our observation contrasts findings showing that cognitive control mechanisms reach their optimal functioning in early adulthood.

La consommation énergétique dans le secteur bâtiment dépend de diverses facteurs parmi lesquels ses caractéristiques physique, ses équipements, l’environnement extérieur, etc… mais il ne faut pas oublier le comportement des habitants qui est déterminant pour la consommation énergétique globale. Or, la plupart des travaux et outils représentent les occupants par des profils d’occupation. Cette thèse s’intéresse à la représentation plus détaillée du comportement des occupants, en particulier les mécanismes cognitifs, réactifs et délibératifs. Le comportement dynamique des occupants est modélisé et co-simulé avec les aspects physiques et des éventuels systèmes de gestion énergétique. L’analyse de la consommation de différents équipements électroménagers met en évidence que le consommation énergétique est très dépendante des comportements des occupants. L’analyse des consommations et des actions des habitants permet d’élaborer un modèle du comportement des occupants impactant la consommation énergétique. Le modèle représente des mécanismes cognitifs, qui représente les causes qui motivent les actions, incluant des échange avec d’autres acteurs humains. Une approche à base d’agents logiciels a été développée. Outre les aspects techniques, une méthodologie de réglage des paramètres des modèles de comportement est proposée. Ces outils sont utilisés pour réaliser une co-simulation représentant la physique du bâtiment, le comportement réactif, c’est-à-dire sensible aux données physiques, et délibératif des habitants mais aussi un système de gestion énergétique qui peut ajuster directement la configuration du logement ou simplement conseiller ces occupants. L’impact de différents types de comportements, avec et sans gestionnaire énergétique est analysé. Ces travaux ouvrent de nouvelles perspectives dans la simulation bâtiment, dans la validation de gestionnaires énergétiques mais aussi dans la représentation des bâtiments dans les réseaux d’énergie dits intelligents, dans lesquels des signaux peuvent être envoyés aux utilisateurs finaux pour les inviter à moduler leur consommation. / Energy consumption in buildings is affected by various factors including its physical characteristics, the appliances inside, and the outdoor environment, etc. However, inhabitants’ behaviour that determines the global energy consumption must not be forgotten. In most of the previous works and simulation tools, human behaviour is modelled as occupancy profiles. In this thesis the focus is more on detailed behaviour representation, particularly the cognitive, reactive, and deliberative mechanisms. The inhabitants’ dynamic behaviour is modelled and co-simulated together with the physical aspects of a building and an energy management system. The analysis of different household appliances has revealed that energy consumption patterns are highly associated with inhabitants’ behaviours. Data analysis of inhabitants’ actions and appliances’ consumptions is used to derive a model of inhabitants’ behaviour that impacts the energy consumption. This model represents the cognitive mechanisms that provide causes that motivate the actions, including the communication with other inhabitants. An approach based on multi-agent systems is developed along with a methodology for parameter tuning in the proposed behaviour model. These tools are used to co-simulate, not only the physical characteristics of the building, the reactive behaviour that is sensitive to physical data, and deliberative behaviour of the inhabitants, but also the building energy management system. The energy management system allows the direct adjustment of the building parameters or simply giving advice to the inhabitants. The impact of different types of inhabitants’ behaviours, with and without the inclusion of an energy management system is analyzed. This work opens new perspectives not only in the building simulation and in the validation of energy management systems but also in the representation of buildings in the smart grid where signals can be sent to end users advising them to modulate their consumption.

There is a paucity of South African data concerning the cross-cultural incidence of attitudes and behaviours associated with eating disorders. Research in this area has recognised that acculturation to a Western value system appears to have a pathogenic impact on the prevalence of disordered eating among non-Western ethnic groups. This study aimed to explore the relationship between acculturation and disordered eating, and to compare the level of disordered eating (as measured by the Eating Disorders Inventory [EDI]) among black and white female university students in KwaZulu-Natal. The roles of Body Mass Index (BMI) and socioeconomic status were also examined. The sample consisted of one hundred and twenty-two white female undergraduate students from the University of Natal (Pietermaritzburg), fifteen black female undergraduate students from the University of Natal (Pietermaritzburg), and one hundred and fifty-four black female undergraduate students from the University of Zululand. It was found that although black subjects obtained significantly higher scores on the Drive for Thinness subscale of the EDI, white subjects obtained significantly higher scores on a combination of the three subscales designated to assess disordered eating attitudes and behaviours. Black subjects obtained significantly higher BMI scores than white subjects, and BMI was positively correlated with Body Dissatisfaction in both groups, and with Drive for Thinness in the white group only. No relationship was found between socioeconomic status and disordered eating. Similarly, no relationship was found between acculturation and disordered eating. This latter result is partly a function of problems experienced with the measures of acculturation. A comparison of black subjects from the two universities suggests that greater contact with white students is influential in terms of the development of disordered eating. The above results are discussed in terms of the available literature, and recommendations for future research are made on the basis of the limitations of this study. The data from this study is included in a nation wide cross-cultural study of eating disorders initiated by the Eating Disorders Co-ordinating Committee. / Thesis (M.A.)-University of Natal, Pietermaritzburg, 1996.

A total sample of 1,105 students from the universities of Natal, Witwatersrand and the North participated in this study. The Eating Attitude Test (EAT) and the Bulimic Investigatory Test, Edinburgh (BITE) were administered to three female and three male student samples. Subjects also provided biographic, demographic and weight-related information. The majority of subjects fell within the average weight range of the Body Mass Index (BMI), with the percentage of underweight Indian subjects being higher than the corresponding percentages of the black and white student groups. The majority of males in each race group have accurate weight perceptions. In contrast, the minority of females (fewer than a third) of Indian and white females and under half of black females have accurate weight perceptions. However, all overweight white females assessed themselves as such and 89% of overweight black women assessed themselves as overweight. In terms of exaggerated weight perceptions, more white and Indian females (72% and 70% respectively) consider themselves as overweight or very overweight when they were actually of average weight, than black females (47%). Females in each race group scored consistently higher on all scales assessed than their male counterparts. White females exhibited the most disturbed eating behaviours and attitudes in terms of the categorised percentage scores obtained on all scales of the BITE and EAT. No Indian males obtained scores in the pathological range. On the EAT scale, 19% of white females, 17% of black females and 9% of Indian females, 7% of black males and 1% of white males obtained scores which were categorised as pathological. The more stringent criteria of the BITE showed a lower percentage of all subjects in the pathological range, albeit still retaining the gender discrepancy. Thirteen percent of white female students, 8% of black females, 3% of Indian females, 2% of white males and 1% of black males obtained a pathological score on the BITE scale. The Indian female and male sample exhibited the healthiest eating behaviours and attitudes relative to the other two racial groups examined. In terms of mean scores a general trend emerged in which black males obtained higher mean scores than white and Indian males, and black females obtained mean scores (which were overall) similar in magnitude to those of white females. The majority of black females who obtained pathological scores were urban raised and were from the upper socio-economic stratum. The majority of white females who obtained pathological scores were from urban backgrounds, had exaggerated weight perceptions and expressed a desire to lose at least 10 kilograms of weight. / Thesis (M.A.)-University of Natal, Pietermaritzburg, 1996.