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The thesis shifts the explanatory framework of depression from the currently predominant clinical model which explains depression as a problem located in the individual, to a social psychological approach which explains depression in terms of its meaning to the individual, as an experience of self, evolved through relationships with others. Theoretically, the thesis draws on Mead's (1934) theory of social hehaviourism, and symbolic interactionism (Blumer 1969). An innovative and interpretative qualitative methodology, "Thematic Analysis", is developed for the analysis of interview accounts acknowledging the perspectives of participants. Analyses are presented as the subjective interpretations of the researcher but accounts are approached as partial representations of real experiences. The methodology of thematic analysis is developed through the research, drawing on grounded theory (Glaser and Strauss, 1967) and discourse analytic techniques (Potter and Wetherell, 1987). The thesis comprises four separate studies to investigate subjective experiences of depression and the meaning of the term "depression", based on in-depth, semi-structured interviews. Study I, an exploratory study with a university population (not necessarily depressed), identifies themes and discourses in accounts of depression. Study II investigates subjective experiences of depression from patients' perspectives, based on accounts of psychiatric out-patients and patients of general practitioners who had been diagnosed as depressed, and identifies the power of the medical discourse in legitimating problems as depression. Study III discusses medical discourses of depression, as used by psychiatrists, general practitioners and clinical psychologists in interview accounts which emphasised the importance of organisational context. Study IV investigates women's experiences of motherhood and depression from participants' perspectives and based on their subjective accounts, and discusses gender identity and the social construction of motherhood as part of their experiences of depression. The analysis indicated that for most respondents depression is both a subjective and a socially constructed experience. The powerful construction of depression as a clinical problem located in the individual may legitimate problematic experiences, hut it is insufficient to explain subjective experiences of depression, which are better understood in terms of the construction of subjectivity through social interaction. The research has implications for more helpful professional and personal approaches to understanding the experience of depression.

Learned associations between rewarding stimuli and environmental cues which predict their availability play an important role in guiding behaviour. These learned associations are thought to be encoded by neuroadaptations in disperse sets of strongly activated neurons, termed neuronal ensembles, located throughout motivationally-relevant brain areas. However to date, the nature of the adaptations which occur selectively on neuronal ensembles encoding appetitive associative memories remain largely unknown. Using the Fos-GFP mouse, which expresses green fluorescent protein (GFP) in recently activated neurons, we investigated the intrinsic and synaptic excitability of neurons activated following exposure to stimuli associated with food (sucrose) or drug (cocaine) exposure. We observed that in the nucleus accumbens (NAc) shell, but not orbitofrontal cortex, neurons activated following exposure to a food-associated stimulus were more intrinsically excitable than surrounding, non-activated neurons. These neurons also demonstrated increased spontaneous excitatory transmission suggestive of potentiated synaptic strength. Following extinction of the food-cue association, NAc shell neurons activated following cue exposure were no longer more excitable than surrounding neurons. This suggests that the intrinsic excitability of striatal neurons activated by a food-associated cue is dynamically modulated by changes in associative strength. We also examined the intrinsic excitability of striatal neurons (including neurons in the NAc shell, core and dorsal striatum) activated by cocaine-associated stimuli. Interestingly, NAc shell neurons activated by cocaine-associated stimuli were not more excitable compared to the surrounding neurons regardless of extinction learning experience, possibly indicating differences between drug and food conditioning. Similar results were obtained for dorsal striatal neurons. However, NAc core neurons activated by cocaine-associated stimuli displayed an enhanced excitability which persisted following extinction, indicating that core and shell neuronal ensembles differentially encode the cocaine associative memories. Overall, by selectively recording from stimuli-activated neurons, this work reveals novel adaptations at the intrinsic and synaptic levels on neuronal ensembles following appetitive learning with both food and drug rewards.

Previous research has implicated the role of food associated cues or pre-task reward exposure with eating behaviour. Eating behaviour (specifically overeating) has itself been associated with subtypes of impulsivity. To date, no research has examined the direct relationship between (food) reward-associated cues, or rewarding food exposure on behavioural impulsivity – a possible underlying mechanism. This thesis aimed to examine how behavioural impulsivity may be modulated by external cues, or by hedonic reward consumption, and how this interacts with eating attitudes (TFEQ). Experiment 1 examined the aims explicitly, giving participants a hedonic preload (or nothing) before they completed impulsivity tasks. Those who received a preload were more impulsive in terms of their impulsive choice, and inhibitory control than those who had not received a preload. This effect did not replicate in experiment 3, where 2 further conditions were added, a non-hedonic preload, and an anticipation condition, but no differences were found between the groups. Experiment 4 conditioned rewarding cues to novel stimuli, and presented them before the behavioural tasks, but again, no difference was found between the groups. This thesis discusses the theoretical and methodological concepts, which may explain some of these null findings. Experiment 2 aimed to examine how the reinforcing value of food (RRV) may be associated with types of impulsivity. However, no relationship was found between RRV and impulsivity, but RRV was consistent in predicting ad libitum food intake, as shown in previous studies. Chapter 6 of this thesis is a meta-analysis of our laboratory's research linking delayed discounting (DDT), the TFEQ, and cue exposure paradigms. The analysis showed that those in high in dietary disinhibition (TFEQ-D) who were shown food cues, or consumed a hedonic preload were more impulsive on the DDT than those high in TFEQ-D that did not consume anything. The key limitations of this thesis are discussed, most notably the lack of statistical power in the experimental studies conducted. The general discussion of this thesis discusses the important implications of this finding in understanding modulation of behavioural impulsivity.

Investigators have suggested impulsivity consists of several behavioural subtypes including ‘reflection'- (decision-making without evaluation of information), ‘temporal'- (failure to delay gratification) and ‘motor'- (failure to inhibit a motor response) impulsivity. These facets of impulsivity are thought to be dissociable, but to share some common underlying processes. The current studies investigated such processes. Study 1 investigated speed and accuracy biases, using instructions and cognitive priming to challenge impulsivity. Study 2 & 3 challenged inhibitory control resources, via a dual task and alcohol challenge, to investigate the effect on impulsivity. Study 3 also investigated the effect of alcohol outcome expectancies on impulsivity. The factor structure of impulsivity was also investigated using exploratory factor analysis (study 4), to establish whether the primary measures of the proposed subtypes can indeed be categorised into these three factors. Study 4 also investigated the relationship of participant demographics to impulsivity. The studies support the suggestion of a distinct subtype of reflection-impulsivity. Inhibitory control processes do not appear to underlie performance, however biases in speed/accuracy trade-offs have implications for this subtype. Behavioural inhibitory control was found to be the primary process underlying motor-impulsivity whilst biases for speed/accuracy have implications for Go-responses. The factor analysis provided preliminary evidence that there may be two distinct facets of motor-impulsivity: action cancellation and action restraint. Inhibitory control processes were not found to underlie temporal-impulsivity on an experiential task. Biases for speed/accuracy were found to contribute to performance on pen-and-paper measures. However, subsequent factor analysis provided evidence that experiential tasks may actually be more closely related to a form of cognitive control, instead of temporal-impulsivity. In conclusion, the studies found that the three proposed factors of impulsivity differentially rely on inhibitory control processes and biases for speed/accuracy. However, factor analysis indicated that additional factors may be required to fully characterise impulsivity.

This thesis focuses on how recalling past behaviour affects attitudes, intentions and behaviour in the domain of moral decision-making. It extends the existing literature on moral licensing and moral cleansing by exploring whether different individual difference variables moderate such licensing and cleansing effects. Five empirical studies are reported. Chapter 1 provides an overview of the moral licensing and moral cleansing literature and also outlines research into the predictive effects of moral norms on behavioural intentions within the structure of the TPB. In chapter 2, the first study reveals evidence of moral cleansing effects: participants in an immoral condition were more likely to donate to charity than were participants in a moral condition or control group. Study 2 investigated whether self monitoring moderated licensing and cleansing effects. Chapter 3 (study 3) investigated the mediation effect of emotion and the moderation effect of moral identity regarding licensing and cleansing effects on attitudes, intentions and moral norm and behaviour. A partial mediation of condition and behaviour by negative emotions was identified. The results also indicated evidence of a cleansing effect. Moreover, in studies 1, 2 and 3 mediation of the moral norms – intention relationship via attitudes was examined. Moral norms were identified as a strong predictor of charitable donation intentions. In Chapter 4, environmental attitude was investigated as a moderator of the effect of individuals' past pro-environmental behaviour on TPB components. Internally motivated pro-environmental attitude was found to be a significant moderator. Chapter 5 draws upon the idea that conception of morality differs in different cultures and examined how different moral foundation values and cultural orientations affect moral attitudes and intentions in the UK and Iran. Surprisingly, moral norms were a more useful predictor of intention than were attitudes in both national cultures.

Previous research employing modulation of 5-HT2C receptors (5-HT2CRs) in rodents has identified a potential role in mediating cognitive flexibility. The work presented in this thesis explores the effects of systemic administration of the selective 5-HT2CR antagonist SB242084 on a range of Pavlovian and operant learning paradigms used to model cognitive flexibility and reward-based learning in mice. Based on a key design difference in previous research reporting discrepant outcomes, trial initiation requirements were manipulated. However the effect of SB242084 administration relative to vehicle-treatment was consistent with prior reports of impaired reversal performance following reductions in 5-HT2CR activity, regardless of whether trials were automatically or self-initiated. In contrast, performance on a probabilistic reversal learning task was enhanced by drug-treatment, raising the possibility that task difficulty mediates the effect of this manipulation on performance. A drug-related enhancement in the ability to overcome learned non-reward at the previously incorrect location was additionally demonstrated under probabilistic reversal conditions, with no effect on perseverance at the previously correct location. However, performance of drug-treated animals in two closely related tasks demonstrated impaired extinction learning but intact development of latent inhibition to a pre-exposed stimulus. The effect of SB242084 on incentive motivation was additionally explored, but did not impact upon the acquisition of a sign-tracking response to a conditioned stimulus, or a subsequent reversal; suggesting that 5-HT2CRs may be more critically involved in instrumental than Pavlovian learning. These experiments reveal a complex picture for the involvement of 5-HT2CRs in flexible cognition, however, systemic manipulations may not be optimal for dissecting their role. Therefore, a final study explored the expression of c-Fos immunoreactivity in response to reversal learning. A broad network was activated by elements of the reversal task, including regions of the prefrontal cortex and amygdala, providing a basis for future studies targeting components of this circuitry.

A better understanding of the psychological mechanisms underpinning addiction will facilitate its remediation. Some evidence suggests that the emotional properties of drug-paired stimuli themselves drive drug-procurement, while other evidence indicates that the expectation of reward elicited by the stimuli is sufficient to control drug-seeking. The current series of experiments aimed to explicate these seemingly contradictory data, by characterising the roles played in reward seeking by conditioned-stimulus-elicited emotion and expectation in non-dependent samples, before assessing their contribution in smokers. Further data suggest a role of personality in addictive behaviours, thus personality was assessed as a moderator of reward-seeking. Variations of a Pavlovian-to-instrumental transfer design, which tests the ability of reward-associated stimuli to modulate reward seeking, together with questionnaires of personality were applied. It was shown that outcome expectation was consistently necessary for cue-potentiated monetary-reward seeking, and similarly in smokers, cigarette outcome expectation was sufficient for cue-potentiated cigarette-reward seeking. Tentative evidence for the role of conditioned-stimulus emotional value in monetary-reward seeking was found, although this latter result requires scrutiny through additional research. Moderating influences of Extraversion and Neuroticism were found for cue-elicited emotion and outcome expectation, respectively. It is therefore proposed that reward expectancy is necessary for conditioned stimuli to control behaviour. The emotional properties of reward-predictive stimuli may be important for reward seeking in the absence of addiction, but when addiction to reward is present, control of reward seeking can occur via reward expectation only. Data from the role of personality, in moderating the effects of stimulus-elicited emotion or outcome expectation on reward-seeking behaviour, suggest that the control of behaviour by emotion may be facilitated by Extraversion, due to its propensity towards emotional processes, whereas control by expectation may be facilitated by Neuroticism, due to its inclination towards predictive learning.

Within classical economics, an agent is deemed “rational” if their preferences are both consistent and maximize utility of positive, subjective experience. Violations from this norm may occur as a result of utility devaluation (proceeding from risk or delay) or when an imbalance occurs between ‘liking' and ‘wanting'. The current studies investigate how changes in reward-contingencies, delay before reward receipt, and reinforcer devaluation contribute to such utility-based decision-making in human and rodent models. I examined the effects of devaluation through pre-exposure and outcome-contingency on the development and maintenance of sign- and goal-tracking responses in rats (chapter three) and humans (chapter four). Chapter four presents a novel, translational, eye-tracking procedure and correlates of such behaviour, including trait-impulsivity and discounting performance. In chapter five I presented probability- and temporal discounting using a mouse model, exploring the consequences of satiety-based devaluation, and changes in outcome-contingencies- and delays. In Chapter six I presented the same factors in a human sample using a novel laboratory-based procedure and sought to explore the impact of trait and state impulsivity and correlates of rapid discounting. Finally, in chapter seven I considered the relationship between trait impulsivity, alcohol use, smoking and discounting behaviour using a more conventional online questionnaire. The results represent some of the first to present probability discounting using a mouse model and characterisation of reliable sign- and goal-tracking performance in humans. The results of the latter studies broadly support previous findings in rats showing that lowered reward contingency diminishes goal-oriented, but enhances sign-oriented, responding. Chapter six establishes a human equivalent to rodent discounting paradigms through implicit learning that will allow future controlled studies in humans. Finally, chapter seven presents evidence for an association between delay discounting and trait impulsivity. The results of these studies support the assertion that irrational decision-making arises, in part, from changes in reward utility as a function of delay, probability, devaluation and individual differences. Furthermore the translational-homologous models presented allow for future biopsychological research into mechanisms underlying such behaviours.

The 2007 revised mathematics curriculum in Ghana introduced many changes to the way mathematics should be taught and learned. However, before this research started in 2010, very little was known about how this subject is taught and learned. This study aims to investigate mathematics teachers’ teaching practices and students’ learning experiences in junior high schools (12-14 years) using a mixed methods design. The study’s conceptual framework is informed by two different, but interrelated theories: behaviourism and constructivism. Participants in the study were 24 mathematics teachers and 358 students from 12 schools. Semistructured questionnaires were used to collect quantitative data about participants’ perceptions, and classroom observations and interviews were used to collect qualitative data about actual classroom practices. The quantitative data was analysed using SPSS, STATSDIRECT and ORIGIN software and the qualitative data assessed using a thematic analysis approach. The key findings include: teachers and students espoused the belief that their teaching and learning practices are consistent with the principles and guidelines of the new mathematics curriculum. Teachers perceived teaching practices were complex as they contain both behaviourist and constructivist beliefs; however, their actual teaching practices were didactic. It also emerged that both teachers and students try to avoid making mistakes, despite the importance of correcting students’ misconceptions when promoting effective teaching and learning. The fact that peer influence is a key factor that shapes students’ learning was an important theme that emerged from the interview and the classroom observations. Students were only willing to participate in class discussions if they knew the correct answer, as they would be ridiculed by their peers for giving a wrong answer. The movement towards a more constructivist approach to teaching and learning, which is the prime objective of the new mathematics curriculum, occurred at a slower pace. Thus, a conceptual model for the teaching and learning of mathematics which advocates collaboration and partnership between teachers and students in the classroom is offered.