This thesis confronts a fundamental shortcoming in cognitive science research: a failure to be explicit about the theory of concepts underlying cognitive science research and a resulting failure to justify that theory philosophically or otherwise. It demonstrates how most contemporary debates over theories of concepts divide over whether concepts are best understood as (mental) representations or as non-representational abilities. It concludes that there can be no single correct ontology, and that both perspectives are logically necessary. It details three critical distinctions that are frequently neglected: between concepts as we possess and employ them non-reflectively, and concepts as we reflect upon them; between the private (subjective) and public (inter-subjective) aspects of concepts; and between concepts as approached from a realist versus anti-realist perspective. Metaphysical starting points fundamentally shape conclusions. The main contribution of this thesis is a pragmatic, meticulously detailed, and distinctive account of concepts in terms of their essential nature, core properties, and context of application. This is done within the framework of Peter Gärdenfors' conceptual spaces theory of concepts, which is offered as a bridging account, best able to tie existing theories together into one framework. A set of extensions to conceptual spaces theory, called the unified conceptual space theory, are offered as a means of pushing Gärdenfors' theory in a more algorithmically amenable and empirically testable direction. The unified conceptual space theory describes how all of an agent's many different conceptual spaces, as described by Gärdenfors, are mapped together into one unified space of spaces, and how an analogous process happens at the societal level. The unified conceptual space theory is put to work offering a distinctive account of the co-emergence of concepts and experience out of a circularly causal process. Finally, an experimental application of the theory is presented, in the form of a simple computer program.

In the universe of problems humans face every day there is subset characterized by a salient dynamic component. The FireChief task (Omodei & Wearing 1995) is a fire-fighting computer simulation that can be characterized as the acquisition of interactive skills involving fast-paced actions cued by external information. This research describes the process followed to create a cognitive model of this complex dynamic task where full experimental control is not available. The cognitive model provides a detailed description of how cognition and perception interplay to produce the interactive skill of fighting the fire. Several artefacts were produced by this effort including a dynamic task fully compatible with ACT-R, a tool for analysing the data, and a cognitive model whose features enable the replication of several aspects of the empirical data. A key finding is that good performance is linked to an effective combination of strategic control with attention to changing task demands, reflecting time and care taken in informing and effecting action. The contributions of this work towards our understanding of complex problem solving are the methodological approach to the creation of the model, the design patterns embedded in the model (which are a reflection of the cognitive demands imposed by the nature of the task) and mainly an explanation of how skill, described in terms of strategy use, is acquired in complex scenarios. This study also provides a deeper understanding of the interactions observed in the Cañas et al. (2005) dataset, including a computational realisation of how cognitive inflexibility occurs.

This research explored strategies for learning programming via worked-examples that promote schema acquisition and transfer. However, learning style is a factor in how much learners are willing to expend serious effort on understanding worked-examples, with active learners tending to be more impatient of them than reflective learners. It was hypothesised that these two learning styles might also interact with learners' cognitive load. The research proposed a worked-example format, called a Paired-method strategy that combines a Structure-emphasising strategy with a Completion strategy. An experiment was conducted to compare the effects of the three worked-examples strategies on cognitive load measures and on learning performance. The experiment also examined the degree to which individual learning style influenced the learning process and performance. Overall, the results of the experiment were inconsistent. In comparing the effects of the three strategies, there were significant differences in reported difficulty and effort during the learning phase, with difficulty but not effort in favour of the Completion strategy. However no significant differences were detected in reported mental effort during the post-tests in the transfer phase. This was also the case for the performance on the post-tests. Concerning efficiency measures, the results revealed significant differences between the three strategy groups in terms of the learning process and task involvement, with the learning process in favour of the Completion strategy. Unexpectedly, no significant differences were observed in learning outcome efficiencies. Despite this, there was a trend in the data that suggested a partial reversal effect for the Completion strategy. Moreover, the results partially replicated earlier findings on the explanation effect. In comparing the effects of the two learning styles, there were no significant differences between active and reflective learners in the three strategy groups on cognitive load measures and on learning performance (nor between reflective learners in the Paired-method strategy and the other strategies). Finally, concerning efficiency measures, there was a significant difference between active learners in the three strategy groups on task involvement. Despite all these, effect sizes ranging from a medium to large suggested that learning styles might have interacted with learners' cognitive load.

In this thesis I develop a novel approach to conscious perception, which I label “radical sensorimotor enactivism” (RSE). In chapter one, I explain how the development of RSE is guided by the tenets of activity and knowledge-how. In chapter two, I outline and explain RSE. Throughout the thesis, I will pit RSE against cognitivist accounts of conscious perception and argue that RSE is to be preferred. In chapters three and four, I highlight two problems facing cognitivist accounts of conscious perception which RSE avoids. I argue that cognitivist accounts of conscious perception face the ‘hard problem of perceptual consciousness', whilst RSE can provide a phenomenologically plausible deflation of this problem. I next explain why cognitivist accounts are incapable of providing a satisfactory explanation of split-brain syndrome. Then, I argue that RSE can provide a parsimonious explanation of this syndrome. Theories predicated on activity and knowledge-how are often rejected for being incapable of accounting for the brain's role in conscious perception. In chapter five, I argue that RSE can account for the brain's role by adopting a non-representational version of predictive processing (PP). Moreover, I argue that the resultant account improves upon cognitivist alternatives. Then, in chapter six, I argue that even representational explanations of PP can be subsumed within RSE by accepting fictionalism about their representational posits. Consequently, I conclude that RSE cannot be objected to for failing to account for the brain's role in conscious perception. Finally, in chapter seven, I discuss ‘non-veridical' experiences. Accounts like RSE are often rejected because it is thought they are incapable of explaining the existence of these phenomena. I explain how the existence of such phenomena is wholly compatible with the truth of RSE. Thus, I conclude that RSE should not be rejected solely on the basis that non-veridical experiences exist.

The greatest genetic factor in how well we age cognitively is Apolipoprotein E (APOE), a single nucleotide polymorphism with three allelic variants: epsilon-2, epsilon-3 and epsilon-4 (hereafter ε2, ε3, ε4). The ε4 allele is associated with an increased risk of cognitive disadvantage in later life, however, the effects of this variant are not isolated to old-age, with some studies reporting cognitive advantages in youth. This thesis investigates the influence of APOE ε4 on cognition from mid-adulthood, a point in the lifespan when the detrimental effects of this allele may be emerging. This thesis begins with a systematic review and meta-analysis of the literature to-date, and suggests attention may be sensitive to ε4 differences in mid-adulthood, however, effects of the allele are not consistently shown, perhaps due to methodological limitations including the use of insensitive neuropsychological batteries (Chapter 1). Next, behavioural paradigms providing a sensitive index of both selective (Chapter 2) and executive attention (Chapter 3), suggest many attentional processes are intact in mid-age (45-55 years) ε4 carriers. Subtle deficits, however, are apparent on prospective memory (PM) and Stroop-switch paradigms, indicating a goal maintenance disadvantage. In addition, a proxy of cognitive reserve was found to moderate the effects of ε4 on executive attention in mid-adulthood (Chapter 4). Follow-up research used paradigms that target the distinct processes supporting focal and non-focal PM to interrogate the profile of change observed in mid-age ε4 carriers, identifying a profile of disadvantage consistent with that observed in pathological ageing (Chapter 5). PM, however, was not found to differentiate ε4 carriers in older individuals at heightened risk of converting to dementia (Chapter 6). Collectively, this research provides evidence for a profile of accelerated ageing in ε4 carriers, with subtle disadvantages apparent in executive attention by the end of the 5th decade.

Our phenomenological experience of what we see around us is of an accurate representation. However, such information is widely distributed in the brain so necessitates that some form of co-ordination of this information takes place to enable a coherent view of the world. The most prominently researched theory is Feature Integration Theory (Treisman, 1993). This proposes that accurate binding is dependent on the current spatial distribution of attention. Individual objects compete for attention via activity in a master map of locations with competition being modulated by grouping processes. When attention is distributed, features are randomly selected and a bound object can be perceived to be located at any position within the attentional window. However, there is evidence to suggest that in distributed attention, coarse location information is available and two alternative proposals have been put forward. The first suggests that it is the information from a unitary feature that can determine the perceived location of a bound object (Tsal & Lavie, 1988) and the second proposes that the information from all contributing features is averaged to provide the location information (Ashby et al, 1996). One way to determine which model best represents feature integration is to investigate the contribution each feature makes to the perceived location of a bound object by using the illusory conjunction paradigm in which an object is formed when the visual system binds together individual features from items located in different parts of the display. Results indicated that in briefly presented displays, perception can be subject to tritan-like shifts in colour space. No support for spatial averaging or for the random rule was found. Rather, there was a strong indication that the perceived location of illusory objects was sourced from a single feature supporting the unitary rule.

Gender stereotypes are activated spontaneously and unintentionally when certain role nouns are read. For example, people expect a builder to be male and a beautician to be female. Such gender inferences lead to processing difficulties when violations of stereotypical gender occur. The aim of this thesis was to devise strategies aimed at overcoming the activation of gender stereotype biases in English. Across nine studies, a variety of stereotype reduction strategies were investigated in conjunction with a judgement task, devised by Oakhill, Garnham and Reynolds (2005). This judgement task asked participants to decide, without deliberation, whether two terms presented onscreen could refer to one person. In the absence of a stereotype-reduction training, participants consistently showed evidence of succumbing to stereotype biases on stereotype incongruent pairings (e.g. Builder/ Mother) compared to stereotype congruent pairings (e.g. Builder/ Father). However, accuracy and response time performance to these incongruent pairings were found to significantly improve from pre-training levels to post-training levels through the use of stereotype reduction strategies such as providing participants with performance-related feedback (Experiment 1, Experiment 3), social consensus feedback (Experiment 4), combined social and accuracy feedback (Experiment 6) and counter-stereotype pictures (Experiment 8). A number of individual difference measures were also administered with the behavioural tasks. These explored whether individual differences in levels of ambivalent sexism, attitudes towards sexist language, sex role perception, and, among others, sexist pronoun use could moderate performance on the judgement task. The results from these additional tasks are described in Chapter 5. This thesis provides further evidence for the malleability of stereotype biases and delineates specific strategies through which stereotype biases can be overcome, to ultimately result in lower levels of stereotype endorsement.

This thesis identifies, in Nancy's The Fall of Sleep, a crucial critique of phenomenology. A criticism that demarcates, or limits, phenomenology in declaring: “There is no phenomenology of sleep”. Taking-up this challenge, we consider a number of ways that phenomenologists have, and could, approach sleep. Our thesis, however, does not simply offer possible responses to the problem but also finds, in these answers, important insights into the essence of the charge itself. Sleep and phenomenology are found to be mutually de-limiting – each binds the other, whilst offering foundational insights into its counterpart. Fundamentally, we bring phenomenologies of sleep, as opposed to simply phenomenology, into dialogue with this, Nancean, critique of phenomenology and with Nancy's account of sleep itself. We describe the distinctly different slumbering interpretations of sleep present, and conspicuously absent, in the work of: Husserl, Heidegger, and Levinas. Part I, after initially elaborating the challenge, presents a direct Husserlian counter, via a recent reconstituting of Husserl's late notes on sleep. The strengths and weaknesses of this phenomenological investigation sharpens the problem of sleep and leads us to pull back from consciousness-centred accounts. Part II, in contrast, develops our own hypothetical Heideggerian answer. This Part, the longest, uses Heidegger's existential and comparative analytics to ask ‘Does Dasein sleep?' This question reveals internal ambiguities of sleep – positioned between existence, life, and death. Part III withdraws from Heideggerian thinking through Levinas's incisive, and early, interpretation of sleep. This Levinasian retracting opens the possibility of returning to Nancy's challenge and corresponding description of sleep. Now this radical account is located in relation to, and in communication with, the somnological-phenomenological findings we have awakened in our thesis. The thesis ends by indicating a possible, future, return back from sleep to phenomenology – a dream, still hazy from sleep, of a somnolent phenomenology.

This thesis breaks new ground by attending to two contemporary developments in art and science. In art, computer-mediated interactive artworks comprise creative engagement between collaborating practitioners and a creatively participating audience, erasing all notions of a dividing line between them. The procedural character of this type of communicative real-time interaction replaces the concept of a finished artwork with a ‘field of artistic communication'. In science, the field of creativity research investigates creative thought as mental operations that combine and reorganise extant knowledge structures. A recent paradigm shift in cognition research acknowledges that cognition is embodied. Neither embodiment in cognition nor the ‘field of artistic communication' in interactive art have been assimilated by creativity research. This thesis takes an interdisciplinary approach to examine the embodied cognitive processes in a ‘field of artistic communication' using a media artwork called Sim-Suite as a case study research strategy. This interactive installation, created and exhibited in an authentic real-world context, engages three people to play on wobble-boards. The thesis argues that creative processes related to Sim-Suite operate within a continuum, encompassing collaborative artistic creation and cooperative creative participation. This continuum is investigated via mixed methods, conducting studies with qualitative and quantitative analysis. These are interpreted through a theoretical lens of embodied cognition principles, the 4E approaches. The results obtained demonstrate that embodied cognitive processes in Sim-Suite's ‘field of artistic communication' function on a continuum. We give an account of the creative process continuum relating our findings to the ‘embedded-extended-enactive lens', empirical studies in embodied cognition and creativity research. Within this context a number of topics and sub-themes are identified. We discuss embodied communication, aspects of agency, forms of coordination, levels of evaluative processes and empathetic foundation. The thesis makes conceptual, empirical and methodological contributions to creativity research.

Reversal learning deficits are a feature of many neuropsychiatric disorders, most notably schizophrenia. These deficits could be due, in part, to altered ability to dissipate either or both associations of previous positive (perseverance) and negative (learned non-reward) valence. Studies reported in this thesis developed an egocentric maze task and a visuospatial operant task for separate assessments of spatial reversal learning, perseverance and learned non-reward in mice. These tasks were subsequently used to assess the cognitive causes for altered performance after manipulations to brain systems recognised to be involved in reversal learning and relevant for human psychopathology, with a specific focus on schizophrenia. NMDA receptor (NMDAr) antagonism through acute phencyclidine did not affect reversal learning in the operant task, but caused general impairments in the maze task. Orbitofrontal (OFC) lesioned mice showed perseverative impairments in the operant task. Mice treated with the 5-HT2C receptor (5-HT2CR) antagonist SB242084 and 5-HT2CR KO mice showed facilitated reversal learning and decreased learned nonreward in the operant task. In the maze task, SB242084 decreased perseverance but increased learned non-reward, while 5-HT2CR KO mice showed perseverance and discrimination learning deficits. The final experimental chapter investigated the effect of SB242084 on touch-screen visual reversal learning in the rat. SB242084 retarded learning in this task. These studies demonstrate that previously non-reinforced associations can be of considerable importance in tasks of cognitive flexibility. The studies also show that the NMDAr, the 5-HT2CR, and the OFC, are involved in reversal learning and can modulate mechanisms related to both perseverance and learned non-reward. Moreover, in reversal learning, few effects of manipulations affecting PFC-functioning, or activity at the NMDAr and 5-HT2CR, generalise across the procedures in the visuospatial, egocentric spatial, and visual domains.