Features of impulsivity underlie multiple psychological disorders. The body of work examining impulsivity has largely focussed on self-report measurement and has incorporated psychological constructs without reference to the broader biological factors that may influence impulsive behaviour. Two studies were conducted to examine whether environmental stress and genetic status associated with dopaminergic and serotonergic function (DRD2, ANKK1 and 5HT2AR genotypes) were predictive of dimensions of impulsivity and risky behaviour (alcohol use). The two studies used a multi-method approach in a non-clinical community sample of young adults (aged 17-25 years). Dopamine is integral to the two leading theories of impulsive personality, Gray's Reinforcement Sensitivity Theory and Cloninger's Psychobiological model of personality. Dopamine plays a crucial role in reward reinforcement circuits in the brain. The A1 allele of the ANKK1 gene (also referred to as TaqIA of the DRD2 gene region) and the CC genotype of the C957T polymorphism of the DRD2 gene have both been associated with reduced D2 dopamine receptor density in key structures linked to brain reward. In addition, a strong body of evidence implicates their involvement in a number of clinical disorders associated with impulsivity. Serotonin function has also been associated with impulsivity in Cloninger's theory and there is also evidence of associations of two polymorphisms of the 2A serotonin receptor gene (5HT2AR T102C and -1438A/G SNPs) with impulsivity. Acute and chronic forms of stress are also important correlates of impulsive behaviour and the two studies directly examined the relationship between genotype, stress and impulsivity. Study 1 (N=180) utilised a cross-sectional design and examined interactions between these polymorphisms and chronic stress exposure on key impulsivity dimensions of reward sensitivity, Novelty Seeking and rash impulsiveness. Participants completed psychological questionnaires measuring chronic stress, dimensions of impulsivity, mood and substance use and provided mouth swab samples of buccal mucosal cells for DNA analysis. The study confirmed the association between A1 and CC allelic status and chronic stress being associated with harm avoidance and sensitivity to punishment. This suggests a role for both dopamine and background stress in impulsive behaviour. Study 2 (N=73) built upon this questionnaire research in the laboratory by utilising experimental psychological paradigms of impulsive behaviour and experimentally manipulating acute stress. Study 2 employed a mixed experimental design with a sub-sample of those studied in the cross-sectional sample. These behavioural paradigms included pre- and post- stress induction administration of the Card Arranging Reward Responsiveness Objective Test (capturing behavioural approach in the presence of reward cues, presumed to reflect reward sensitivity) and post-induction delay discounting and response inhibition measures. Study 2 confirmed the role of one of the two dopamine-related polymorphisms, with those with A1+ allelic status demonstrating lower reward responsiveness prior to rest or stress induction, which was overcome in the second administration of this task, independent of environment. A1+ allelic individuals also demonstrated significantly poorer response inhibition independent of stress, further confirming the association between A1+ allelic status and impulsivity. Those with CC allelic status showed an increase in reward responsiveness only in the stress induction condition. Together, results from the two studies inform the development of a multidimensional model of impulsivity that captures gene-environment influences on discrete aspects of impulsive personality and behaviour. Further refinement of this model may lead to the development of more effective customised prevention and treatment interventions for clinically disordered impulsivity. The implications of dopaminergic systems and stress in understanding disorders such as ADHD and substance dependence are discussed.

Because little was known about how the masonry lighthouses constructed during the 19th century at exposed locations around the British Isles were responding to wave action, the dynamic response of the Eddystone lighthouse under wave impacts was investigated. Like other so called 'rock lighthouses', the Eddystone lighthouse was built on top of a steep reef at a site that is fully submerged at most states of the tide. Consequently, the structure is exposed to loading by unbroken, breaking and broken waves. When the breaking occurs, wave loading leads to complex phenomena that cannot be described theoretically due to the unknown mixture of air and water involved during the wave-structure interaction. In addition, breaking waves are generally distinguished from unbroken and broken wave due to the fact that they cause impulsive loads. As a consequence, the load effects on the structural response require a dynamic analysis. In this investigation the dynamic response of the Eddystone lighthouse is investigated both in the field and by means of a small-scale model mounted in a laboratory wave channel. In particular, field data obtained by the use of geophones, cameras and a wave buoy are presented together with wave loading information obtained during the laboratory tests under controlled conditions. More than 3000 structural events were recorded during the exceptional sequence of winter storms that hit the South-West of England in 2013/2014. The geophone signals, which provide the structural response in terms of velocity data, are differentiated and integrated in order to obtain accelerations and displacements respectively. Dynamic responses show different behaviours and higher structural frequencies, which are related to more impulsive loads, tend to exhibit a predominant sharp peak in velocity time histories. As a consequence, the structural responses have been classified into four types depending on differences of ratio peaks in the time histories and spectra. Field video images indicate that higher structural frequencies are usually associated with loads caused by plunging waves that break on or just in front of the structure. However, higher structural velocities and accelerations do not necessarily lead to the largest displacements of around a tenth of mm. Thus, while the impulsive nature of the structural response depends on the type of wave impact, the magnitude of the structural deflections is strongly affected by both elevation of the wave force on the structure and impact duration, as suggested by structural numerical simulations and laboratory tests respectively. The latter demonstrate how the limited water depth strongly affects the wave loading. In particular, only small plunging waves are able to break on or near the structure and larger waves that break further away can impose a greater overall impulse due to the longer duration of the load. As a consequence of the depth limited conditions, broken waves can generate significant deflections in the case of the Eddystone lighthouse. However, maximum accelerations of about 0.1g are related to larger plunging waves that are still able to hit the lighthouse with a plunging jet. When compared to the Iribarren number, the dimensionless irregular momentum flux proposed by Hughes is found to be a better indicator concerning the occurrence of the structural response types. This is explained by the fact that the Iribarren number does not to take into account the effects of the wide tidal range at the Eddystone reef, which has a strong influence on the location of the breaking point with respect to the lighthouse. Finally, maximum run up were not able to rise up to the top of the lighthouse model during the laboratory tests, despite this having been observed in the field. As a consequence, the particular configuration of the Eddystone reef and the wind could have a considerable bearing and exceptional values of the run up, greater than 40 m, cannot be excluded in the field.

A considerable percentage of the UK population are overweight (BMI≥25kg/m2) or obese (BMI≥30kg/m2). However, despite living in the same culture and exposed to a similar “obesogenic” environment, some individuals gain weight while others do not (French et al., 1995). This variability in weight control has been suggested to be associated with individual differences in eating behaviours (French et al., 2012). Certain factors, such as motivation (hedonic hunger and hunger status) as well as cognition (impulsivity and memory) may have an impact on eating behaviours and their relationship with weight control. Thus, the objective of this thesis was to explore individual differences in eating behaviours and investigate their relationship with motivation, cognition and weight control. The first experiment (Chapter 2) investigated the relationship between eating behaviours, motivation (hedonic hunger) and food consumption during an ad-libitum buffet. This study suggests that restrained eating behaviour was associated with higher overall energy intake, greater energy intake from unhealthy foods and greater energy intake from both high and low energy dense foods. However, no interactions between restraint and disinhibition or hedonic hunger was seen. Following this, the second experiment (Chapter 3) examined whether eating behaviours, such as disinhibition, restraint and hunger, change during a weight loss and weight maintenance period and whether they could predict changes in weight during these periods. Indeed, the results suggest that lower baseline restraint could predict greater weight loss during a low-energy liquid diet and interventions which increase restraint and decrease disinhibition may be beneficial for longer term weight maintenance. The third experiment (Chapter 4) was designed to investigate whether motivation and cognition influences eating behaviours. The results suggest that hedonic hunger, restraint and impulsivity may lead to higher levels of disinhibited eating behaviour. This study was also able to replicate the findings of previous literature suggesting that episodic memory is negatively associated with BMI (Cheke et al., 2016). Finally, following on from the previous study results, the fourth experiment (Chapter 5) included a more diverse sample of participants including dieters. The results provide evidence that individuals on a diet have poorer episodic memory ability than those currently not on a diet. This study also extended previous results suggesting that hedonic hunger (but also episodic memory and hunger) are important factors in disinhibited eating. Hedonic hunger was also shown to be important in levels of hunger.

The aim of this study was to create awareness of the emotional needs of children diagnosed with ADHD. In order to reach the aim of this study, an initial literature study was executed to describe ADHD and the emotional needs of children. Semi-structured interviews and two projective techniques were used to conduct the empirical study. Valuable data was also collected from the biographical questionnaires completed by the parents. Based on the data collected and analysed, findings were made which were verified by means of a second literature study. This was followed by conclusions which served as the basis for recommendations that were made in the form of guidelines to the parents, with the aim to make the parents aware of the emotional needs of their children diagnosed with ADHD. These guidelines will be made available to the parents at a seminar that will be held on acceptance of this research. / Social Work / M.Diac. (Play Therapy)

No description available.

Learners with Attention Deficit Hyperactivity Disorder (ADHD) traditionally display disruptive and other associated negative behaviour in the classroom setting. Behaviour management strategies utilised by the teacher in the school environment can assist in reducing this type of behaviour that impacts negatively upon their academic performance. This research study develops and investigates the effectiveness of a programme of practical behaviour management strategies designed to reduce disruptive behaviour of learners with ADHD in the classroom. / Educational Studies / M. Ed. (Educational Psychology)

Psychology / M.A. (Psychology)

Learning disabilities are a life-long problem for many individuals. Besides the adjustments all adolescents experience in life, learning disabled adolescents must contend with academic problems at school which have a drastic effect on their selfesteem. This becomes particularly evident when these pupils face the demands of the secondary school syllabus where they have to be able to concentrate, read for information, memorise facts, answer questions and solve problems, and write assignments. By the time learning disabled adolescents reach secondary school they have already experienced so much failure that they become passive towards their studies. Teaching these pupils metacognitive learning strategies covering these skills helps them to become more independent learners. Through executive training procedures they are assisted to become more involved in their studies, the promotion of better self-regulation and self-monitoring is fostered, and as their scores improve, so does their motivation and selfconcept / Educational Studies / M.Ed. (Orthopedagogics)

Introdução: o Diabetes Mellitus é uma epidemia mundial de incidência crescente e alta morbi-mortalidade. Apesar de a neuropatia diabética ser a complicação neurológica mais comum, é crescente o conhecimento de que existe um acometimento do sistema nervoso central, notadamente no que concerne às alterações cognitivas. Objetivos: investigar, por meio de duas tarefas cognitivas objetivas, simples, rápidas, de baixo custo e de fácil aplicação, diferenças entre pacientes com Diabetes Mellitus Tipo 1 (DM1) e controles quanto a medidas de atenção e impulsividade, componentes-chave das funções executivas tradicionalmente avaliados por questionários subjetivos, longos, de difícil reprodutibilidade e que exigem psicólogos treinados; correlacionar as diferenças encontradas com características clínicas; explorar as correlações entre as duas tarefas. Métodos: Foram comparados os desempenhos de 20 pacientes com DM1 e 20 controles, de ambos os sexos, com idades entre 12 e 15 anos, utilizando a tarefa Agir-Não Agir e uma tarefa de Labirintos, e verificadas correlações entre eles. Resultados: o grupo DM1 teve mais respostas antecipatórias (RA) na tarefa Agir-Não Agir (p<0,05) e fez mais mudanças de trajetória nos Labirintos (p <0,01). Houve correlação entre hipoglicemias não-graves e RA (p=0,01), e entre hipoglicemias graves e número de toques nas paredes dos labirintos (p <0,05). HbA1c> 9% correlacionou-se com um maior número de becos sem saída nos labirintos (p <0,05). Os parâmetros mostraram-se coerentes dentro de cada tarefa e entre elas. Conclusões: Encontramos indicadores de desatenção e impulsividade coexistindo no DM1, o primeiro estando mais relacionado à hiperglicemia, e o último à hipoglicemia. Investigações adicionais são necessárias para estudar o declínio cognitivo associado ao diabetes por meio de avaliações mais objetivas, e avaliar a confiabilidade e as propriedades psicométricas das tarefas aqui propostas. / Background : Diabetes Mellitus is a worldwide epidemic of increasing incidence and high morbidity and mortality. Although diabetic neuropathy is the most common neurological complication, the knowledge that there is an involvement of the central nervous system is increasing, especially in relation to cognitive changes. Aims: To investigate with two simple, inexpensive, rapid, objective and easy-to-apply tasks, differences between patients with Type 1 Diabetes Mellitus (T1DM) and controls in outcome measures of attention and impulsivity, key-executive function components traditionally assessed by subjective and long questionnaires of difficult reproducibility that require trained psychologists; to correlate the alterations with clinical characteristics; to explore correlations between the tasks. Methods: We compared the scores of 20 T1DM to 20 controls, both sexes, aged 12 to 15 years, using a Go-NoGo and a Maze task, and verified correlations between them. Results: T1DM group had more anticipatory answers (AA) in Go-NoGo task (p<0,05) and made more direction changes in Mazes (p<0,01). There was correlation between non-severe hypoglycaemias and AA (p=0,01), and between severe hypoglycaemias and number of touches in Mazes’ walls (p<0,05). HbA1c>9% correlated to a greater number of alleys in Mazes (p<0,05). The tasks’ parameters were coherent among each task and between them. Conclusions: We found indicators of inattention and impulsivity coexisting in T1DM, the first more related to hyperglycaemia and the later to hypoglycemia. Further research is needed to study diabetes-associated cognitive decline with more objective parameters and evaluate the reliability and psychometric properties of the tasks herein proposed. / Dissertação (Mestrado)

One of the factors significantly influencing our daily decisions is the so-called cognitive depletion.The theory of cognitive depletion postulates the existence of a limited mental resource that is necessary for self-regulation. If the resource is diminished by a task involving self-control, achievement in subsequent self-control task will be impaired. This project examines the effect of cognitive depletion on decisions in the Iowa Gambling Task designed to simulate real-life decision making involving gains and losses. Further, a possible effect of moderating factors that could be affected by cognitive depletion and consequently influence decisions in the Iowa Gambling Task -- risk preference and impulsivity -- is investigated. Dual-process theories postulate there are two systems involved in decision-making: faster, intuitive, emotional System 1 and slower, deliberative, rational System 2. It was found that cognitive depletion leads to enhancement of System 1. As advantageous decisions in the Iowa Gambling Task are closely related to emotional reactions -- domain of System 1 -- it was hypothesized that cognitive depletion will lead to not worse, or possibly even better results in depleted subjects. A controlled laboratory experiment was conducted involving 39 subjects in total. No difference was found in average desicions of depleted and non-depleted subjects in the Iowa Gambling Task, supporting the hypothesis. Further, short-term increase in impulsivity caused by cognitive depletion was very probably moderating choices in the IGT, leading to worse overall performance. Regarding risk preferences, we found that non-depleted subjects were generally more risk seeking in losses context, while depleted subjects exhibited rather loss aversion. This change in risk behaviors due to cognitive depletion very probably did not mediate choices in the Iowa Gambling Task.