Dissertations / Theses on the topic 'Cognitive and Behavioural Neuroscience'
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Hsu, Chun-Wei. "A behavioural and cognitive neuroscience investigation of deceptive communication." Thesis, University of Plymouth, 2018. http://hdl.handle.net/10026.1/11984.
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There is a rich literature on how people tell lies and detect them in others, but the underlying mechanisms are still poorly understood. The first aim of this thesis was to elucidate key cognitive and neural processes underlying cued (i.e., instructed) and uncued lies. The second aim, based on recent research suggesting a link between dishonesty and creativity, was to determine whether creative cognition contributes to deceptive communication. In a first behavioural study, performance on generating and detecting lies was measured in a socially interactive setting involving cued and uncued lies. Results of a multiple regression analysis showed that creativity predicted lying generation ability: more creative individuals were better liars than less creative people. In contrast, the ability to detect lies showed no association with creativity measures, suggesting that generating and detecting lies are distinct abilities. A second event-related potential (ERP) study investigated the neural mechanisms underlying the generation of uncued lies using a novel bluffing paradigm where participants lied at will. Results showed no stimulus-locked differences between uncued lies and truths, suggesting that decision processes leading to both required comparable cognitive resources. Once the uncued decision has been made, it requires strategic monitoring to keep track of the responses in order to maximize the gains regardless of whether the outcome is a lie or the truth as indexed by no response-locked differences between uncued lies and truths. Finally, parallel functional magnetic resonance imaging (fMRI) and ERP studies were conducted to determine the role of creativity in countermeasure use in a concealed information paradigm requiring cued lying. Results showed that countermeasures degraded the neural signatures of deception and more so for more creative individuals. This work advances understanding of the cognitive and neural mechanisms underlying deception as well as their dependence on individual differences in creative cognition.
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Kanso, Riam. "The effect of interpersonal power on cognitive processing : a behavioural and neural perspective." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:cdde1f31-890a-444e-85fe-09b09348fcf1.
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Interpersonal power, defined as the asymmetrical control over valued outcomes, has important effects on the way cognitive processing unfolds. This work explores the effect of power on basic cognitive processes, in addition to broader processes that appear at the level of social behaviour. I begin this thesis with an introductory chapter, followed by a chapter describing the theory and practice behind electro-encephalogram recordings. In Chapter 3, I explore the effect of power on attention selection using a task that requires the ability to focus or divide attention in space, while varying the amount of distractors. The results suggest that low-power participants (subordinates) are more susceptible to the presence of distractors, regardless of whether the task necessitates focused or divided attention. In this context, inhibition accounts for the results to a greater extent than spatial orienting. In Chapter 4, I explore the effect of power on early inhibition processes in the context of executive control, in a task which allows participants to allegedly observe each others’ performance and receive feedback. The results show that high power is associated with reduced behavioural accuracy on trials that require executive control. Event-related potential analyses show that power-holders devote reduced motivational resources to their targets compared to subordinates, but do not differ at the level of early conflict detection. Their feedback potential results show a greater expectation of rewards, but reduced subjective magnitude attributed to losses. Subordinates, on the other hand, are asymmetrically sensitive to power-holders’ targets. They expect fewer rewards, but attribute greater significance to losses. In Chapter 5, I show that subordinates are asymmetrically competent at remembering diagnostic choices made by power-holders. In a final general discussion chapter, I integrate the findings of the experiments, which point to multi-layered effects of power, conferring those who possess it and those who lack it with distinct cognitive processing styles that suit their adaptive needs. The results are consistent with a hypothesized link between subordination and up-regulation of vigilance and environmental sensitivity. Limitations and future directions are discussed.
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Richter, Franziska Rebekka. "The control of task sets and long-term memory." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:6537ad2c-107b-4517-8b37-7d5d59edbe3b.
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The current thesis explores the complex relationship between cognitive control and memory. A series of experiments combined task-switching paradigms with recognition memory tests to measure how switching between tasks influences effective control over long-term memory. In these experiments, participants were presented with compound stimuli consisting of a picture and an overlaid word, and were cued in each trial whether the word or the picture was relevant (attended) or irrelevant (unattended). Participants were then tested for their memory of items presented during task switching. Experiments 1-2 indicated that switching between tasks reduces the selectivity of processing: Switching was associated with impaired task performance as well as more similar memory ratings for attended and unattended items. Experiments 3-5 extended these findings by showing that enhanced top-down control positively affected task-performance as well as memory, in both cases by increasing the selectivity of processing toward task-relevant information. Experiments 6-7 replicated key effects with simple switches of visual attention, and explored the neural correlates of successful task performance and encoding using EEG. The key finding here was that previously observed ―subsequent memory‖ effects reflect, at least in part, selective encoding processes. The last chapter extended the focus of the investigation to explore the role of control in long-term memory retrieval. FMRI meta- analyses indicated considerable overlap in neural activation found during task switching and during the adoption of different retrieval sets. The results of Experiment 8 indicated that switching during task performance and later memory retrieval were both associated with decreased selectivity of processing. Collectively, the results of this thesis suggest that selectivity of processing is a critical factor in effective task performance and successful memory, with potentially very similar mechanisms underlying the two. This work demonstrates the fruitfulness of combining research on cognitive control and memory to study questions relevant for both fields.
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Ahmad, Asma. "The role of the prefrontal cortex in pain modulation." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:d959eb19-c859-48a4-9a29-2f120d6f629f.
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Existing knowledge identifies the prefrontal cortex (PFC) as the modulatory area for pain. Previous neuroimaging studies suggest the existence of the cortico-cortical pathway, an alternative pain modulatory pathway distinct from the descending modulatory pathway of pain. However, little is known of the extent, mechanism and underlying substrate of the modulation. The objective of this study is therefore to explore the role of the PFC in pain modulation. To examine the extent of PFC involvement in pain, meta-analyses of imaging studies in healthy volunteers and patients with chronic pain were performed. Using Gaussian-process regression (GPR) analysis, brain maps were produced from foci of activation as reported in the studies. Since structure dictates function, our next study was to performprobabilistic tractography on diffusion-weighted brain images to ascertain the connection probability of lateral PFC subdivisions and pain-related brain regions as well as intrinsic PFC connections. Two behavioural studies were conducted to investigate cognitive modulation of pain. The first was a study to assess the subjective and physiological correlates of cognitive stress, as previously used in stress-induced analgesia studies. The second was to investigate the involvement of the endogenous opioid system inthe cognitive modulation of pain through effortful reappraisal and contextual modulation. Meta-analyses in healthy volunteers and chronic pain patients revealed activation mainly in the lateral aspect of the PFC due to pain. Distinct pattern of activation was demonstrated in patients with significant ventrolateral PFC (VLPFC) activation across subtypes of chronic pain. Probabilistic tractography further illustrate the functional significance of lateral PFC subdivisions by demonstrating differential connection probability to pain-related brain regions; dorsolateral PFC (DLPFC) regions displayed higher connection probability with brain regions serving more sensory-discriminative function while VLPFC showed high connection probability with both sensory-discriminative and affective regions. Behavioural study of stress showed that cognitive stress failed to induce significant increases in biomarkers of stress, and was not affected by increased level of difficulty. Lastly, behavioural study on contextual modulation and reappraisal confirmed opioid mediation for contextual modulation while negating its involvement in effortful reappraisal. Findings from this studyillustrate the extent of PFC involvement in pain modulation especially in chronic pain patients and provide further evidence of an alternative pathway distinct from the opioid-mediated descending inhibitory pathway.
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Kolling, Nils Stephen. "Decision making, the frontal lobes and foraging behaviour." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:ea509f5e-dca4-44e5-9f3f-f7d6550e5b45.
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The aim of this thesis was to understand the function of the frontal lobes during different types of decisions thusfar mostly neglected in cognitive neuroscience. Namely, I sought to understand how decisions are made when comparisons are not about a simple set of concrete options presented, but rather require a comparison with one specific encounter and a sense of the value of the current environment (Chapter 2-3). Additionally, I wanted to understand how decisions between concrete options can be contextualized by the current environment to allow considerations about changing environmental constraints to factor into the decision making process (Chapter 4-5). At last, I wanted to test how the potential for future behaviours within an environment has an effect on peoples decisions (Chapter 6). In other words, how do people construct prospective value when it requires a sense of own future behaviours? All this work was informed by concepts and models originating from optimal foraging theory, which seeks to understand animal behaviours using computational models for different ecological types of choices. Thus, this thesis offers a perspective on the neural mechanisms underlying human decision making capacities that relates them to common problems faced by animals and presumably humans in ecological environments (Chapter 1 and 7). As optimal foraging theory assumes that solving these problems efficiently is highly relevant for survival, it is possible that neural structures evolved in ways to particularly accommodate for the solution of those problems. Therefore, different prefrontal structures might be dedicated to unique ways of solving ecological kinds of decision problems. My thesis as a whole gives some evidence for such a perspective, as dACC and vmPFC were repeatedly identified as constituting unique systems for evaluation according to different reference frames. Their competition within a wider network of areas appeared to ultimately drive decisions under changing contexts. In the future, a better understanding of those changing interactions between these prefrontal areas which generate more complex and adaptive behaviours, will be crucial for understanding more natural choice behaviours. For this temporally resolved neural measurements as well as causal interference will be essential.
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Ang, Yuen Siang. "Brain mechanisms underlying option generation for behaviour." Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:46f4faad-b39d-4d9a-b68b-a765abb32098.
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This thesis examines the highly interlinked fields of voluntary action, apathy and option generation. Substantial research have now implicated the medial frontal cortex in voluntary actions, but the exact roles of each region remain unclear. Seeking clarity on this is important because the lack of self-generated behaviour is characteristic of apathy, a debilitating condition prevalent in neurodegenerative diseases and occurring to varying degrees in healthy individuals. Unfortunately, the conceptualization of apathy is currently unclear. Proposals of its underlying cognitive mechanisms have also mostly focused on deficits in selecting between options and learning outcomes during feedback. Intriguingly, the possibility that an inability to self-generate options may contribute to apathy has never been examined. This is because neuroscientific research on option generation is sparse. Here, a major contribution was the advancement of our understanding of option generation for behaviour. As there was no suitable objective measure available in the current literature, a simple, quantitative and culture-free task to assess option generation was first developed. The task was then administered to patients with Parkinsonâs disease and utilised in two pharmacological studies of dopamine agonist (cabergoline) and antagonist (haloperidol). These provided the first direct evidence that dopamine modulates option generation for behaviour in humans, specifically in the aspects of fluency (generating many options) and uniqueness (how different each option is from others). The ability to generate options was also found to associate with apathy in the healthy population. Besides that, the multidimensional structure of apathy was examined via the development and rigorous validation of a new questionnaire known as the Apathy Motivation Index. Finally, a functional neuroimaging experiment in healthy individuals revealed that the pre-supplementary motor area plays a key role in planning during volitional decisions of what action to execute. Together, these findings have provided new insights and point to new directions for future work in this field.
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Boldt, Annika. "Metacognition in decision making." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:5d9b2036-cc42-4515-b40e-97bb3ddb1d78.
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Humans effortlessly and accurately judge their subjective probability of being correct in a given decision, leading to the view that metacognition is integral to decision making. This thesis reports a series of experiments assessing people’s confidence and error-detection judgements. These different types of metacognitive judgements are highly similar with regard to their methodology, but have been studied largely separately. I provide data indicating that these judgements are fundamentally linked and that they rely on shared cognitive and neural mechanisms. As a first step towards such a joint account of confidence and error detection, I present simulations from a computational model that is based on the notion these judgements are based on the same underlying processes. I next focus on how metacognitive signals are utilised to enhance cognitive control by means of a modulation of information seeking. I report data from a study in which participants received performance feedback, testing the hypothesis that participants will focus more on feedback when they are uncertain whether they were correct in the current trial, whilst ignoring feedback when they are certain regarding their accuracy. A final question addressed in this thesis asks which information contributes internally to the formation of metacognitive judgements, given that it remains a challenge for most models of confidence to explain the precise mechanisms by which confidence reflects accuracy, under which circumstances this correlation is reduced, and the role other influences might have, such as the inherent reliability of a source of evidence. The results reported here suggest that multiple variables – such as response time and reliability of evidence – play a role in the generation of metacognitive judgements. Inter-individual differences with regard to the utilisation of these cues to confidence are tested. Taken together, my results suggest that metacognition is crucially involved in decision making and cognitive control.
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Ginty, Annie T. "The behavioural, cognitive, and neural correlates of blunted physiological reactions to acute psychological stress." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3618/.
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The overarching aim of this thesis was to better understand the behavioural, cognitive, and neural corollaries of blunted cardiovascular and/or cortisol reactions to acute psychological stress. As such, it was also concerned to further test the proposition that blunted cardiovascular and cortisol reactions to acute psychological stress are markers of an unconscious dysfunction in the motivational areas of the brain. These aims were achieved by using a mixed methods interdisciplinary approach encompassing both laboratory stress studies and secondary analyses of epidemiological datasets. Chapter 2 adduced evidence that blunted cardiovascular and cortisol reactivity was associated with a non-substance addiction, namely exercise dependence. Chapter 3 demonstrated that blunted cardiovascular and cortisol reactivity was related to disordered eating behaviour. Differences in stress reactivity between healthy controls and exercise dependent individuals or disordered eaters could not be explained by actual stress task performance, how engaged or how stressful participants found the stress task, cardio-respiratory fitness, and a number of other potential confounders. Chapters 4, 5, and 6 demonstrated that poor cognitive ability was associated with blunted stress reactivity retrospectively, cross-sectionally, and prospectively. Additionally, Chapter 6 demonstrated that blunted cardiac reactivity predicted cognitive decline over a 7 year period. Chapter 7 revealed brain activation differences between pre-determined exaggerated and blunted cardiac stress reactors during an acute stress exposure in a fMRI paradigm. Blunted cardiac reactors showed hypo-activation in the areas of the brain associated with motivation and emotion compared to exaggerated reactors. There were no reactivity group differences in subjective measures of the stressfulness and difficulty of and engagement with the stress task. Overall, the research reported in this thesis provides further evidence that blunted cardiovascular and cortisol reactions to stress are associated with a number of adverse health and behavioural outcomes and may be a peripheral marker of some form of disengagement in those areas of the brain that support motivated behaviour.
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Camm, Emily Jane 1976. "The effects of prenatal hypoxia on postnatal cognitive function : a behavioural, pharmacological and structural analysis." Monash University, Dept. of Physiology, 2002. http://arrow.monash.edu.au/hdl/1959.1/7907.
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Coulson, Louisa Katie. "The influence of emotional stimuli on cognitive processing during transient induced mood states." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:b8fc9fab-e9e0-4b3f-b78e-c76e25224972.
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Selective attention is a mechanism used to allocate resources to information processing. Both mood states and emotionally salient stimuli can influence which information is selectively attended. This information is subsequently processed in a more elaborative manner and affects task performance. The experiments presented in this thesis explore the influence of mood and emotional stimuli on selective attention and consequently task performance. Mood induction procedures were used to induce transient neutral, sad, and happy mood states in healthy volunteers. A systematic review and meta-analysis of 41 studies using sad mood induction procedures showed cognitive impairments in performance in the context of task neutral stimuli. In contrast biases in attention towards mood-congruent negative stimuli led to improved task performance. A series of three behavioural experiments with 197 participants demonstrated that participants made decisions on the basis of less information when that information was preceded by emotional but not neutral stimuli. Induced mood state did not affect performance. The behavioural and neural correlates of visual attentional processing to emotional stimuli were explored using magnetoencephalography in 24 healthy participants following sad, happy, and neutral mood induction procedures. The M300, a component associated with selective attention, had greater amplitude following presentation of negative compared with positive stimuli, which was associated with improved task performance. Reduced M300 amplitude and impairments in performance occurred following sad mood induction procedures. The experiments presented in this thesis demonstrate prioritized processing of emotional information and provide some evidence for impaired performance following sad mood induction procedures.
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Parise, Cesare Valerio. "Signal compatibility as a modulatory factor for audiovisual multisensory integration." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:ec36fab1-9209-4579-a043-6f990b7ec553.
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The physical properties of the distal stimuli activating our senses are often correlated in nature; it would therefore be advantageous to exploit such correlations to better process sensory information. Stimulus correlations can be contingent and readily available to the senses (like the temporal correlation between mouth movements and vocal sounds in speech), or can be the results of the statistical co-occurrence of certain stimulus properties that can be learnt over time (like the relation between the frequency of acoustic resonance and the size of the resonator). Over the last century, a large body of research on multisensory processing has demonstrated the existence of compatibility effects between individual features of stimuli from different sensory modalities. Such compatibility effects, termed crossmodal correspondences, possibly reflect the internalization of the natural correlation between stimulus properties. The present dissertation assesses the effects of crossmodal correspondences on multisensory processing and reports a series of experiments demonstrating that crossmodal correspondences influence the processing rate of sensory information, distort perceptual experiences and lead to stronger multisensory integration. Moreover, a final experiment investigating the effects of contingent signals’ correlation on multisensory processing demonstrates the key role of temporal correlation in inferring whether two signals have a common physical cause or not (i.e., the correspondence problem). A Bayesian framework is proposed to interpret the present results whereby stimulus correlations, represented on the prior distribution of expected crossmodal co-occurrence, operate as cues to solve the correspondence problem.
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Bourne, Corin. "Trauma and the peri-traumatic cognitive mechanisms involved in flashback formation." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:1d42715a-7eef-4b16-9f5b-14aca89f11ed.
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Post-traumatic stress disorder (PTSD) is classified as an anxiety disorder in the Diagnostic and Statistical Manual IV of the American Psychiatric Association. It is characterised by three main symptom clusters: re-experiencing (of which flashbacks are the hallmark symptom); hyperarousal; and avoidance. Diagnosis requires not only the occurrence of a traumatic event but also an intense emotional (fear, horror, or helplessness) reaction to it. Epidemiological data suggest that 80% of people will experience at least one qualifying event in their lifetime. However, prevalence rates of PTSD are much lower. Additionally, individuals with PTSD tend to experience flashbacks of only two or three particular ‘hot-spots’ of the entire trauma. Therefore, the question arises: why do some moments of trauma flash back and not others? Clinical-cognitive theories of PTSD suggest that shifts in information processing at the time of the trauma (i.e. peri-traumatically) are the mechanism whereby flashbacks are created. However, for ethical and practical reasons peri-traumatic processes in real trauma are seldom studied. An analogue traumatic event has been developed to help study peri-traumatic processes – the trauma film paradigm. This paradigm is used through-out this thesis with the goal of investigating peri-traumatic cognitive mechanisms in flashback formation. Studies 1 and 2 extend previous work using dual tasks to manipulate intrusions in-line with clinical-cognitive theories. Studies 3 and 4 use neuroimaging techniques to investigate brain regions involved in real-time peri-traumatic encoding of analogue flashbacks. Chapter 9 presents heart rate data relating to peri-traumatic physiological response to flashback encoding. All of these studies support the notion that peri-traumatic shifts in processing are involved in flashback formation. In particular, Study 3 suggests that there may be a particular neural signature associated with the formation of flashbacks. Investigation of these brain areas may help solve the questions of why some individuals are more vulnerable to PTSD and why only a few specific moments of a trauma subsequently flashback. Furthermore, an improved understanding of the cognitive mechanisms involved in flashback formation may allow theory and evidence led improvements in PTSD treatments.
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Clark, Ian Alexander. "A clinical neuroscience investigation into flashbacks and involuntary autobiographical memories." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:04f72e37-73fe-4347-8af1-8d8852c05f1b.
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Recurrent and intrusive distressing recollections of trauma are a hallmark symptom of Posttraumatic Stress Disorder (PTSD). The term ‘flashback’ is used in this thesis to refer to vivid, sensory perceptual (predominantly visual images), emotional memories from a traumatic event that intrude involuntarily into consciousness. Furthermore, intrusive image based memories occur in a number of other psychological disorders, for example, bipolar disorder and depression. Clinically, the presence and occurrence of flashbacks and flashback type memories are well documented. However, in terms of the neural underpinnings there is limited understanding of how such flashback memories are formed or later involuntarily recalled. An experimental psychopathology approach is taken whereby flashbacks are viewed on a continuum with other involuntary autobiographical memories and are studied using analogue emotional events in the laboratory. An initial review develops a heuristic clinical neuroscience framework for understanding flashback memories. It is proposed that flashbacks consistent of five component parts – mental imagery, autobiographical memory, involuntary recall, attention hijacking and negative emotion. Combining knowledge of the component parts helped provide a guiding framework, at both a neural and behavioural level, into how flashback memories may be formed and how they return to mind unbidden. Four studies (1 neuroimaging, 3 behavioural) using emotional film paradigms were conducted. In the first study, the trauma film paradigm was combined with neuroimaging (n = 35) to investigate the neural basis of both the encoding and the involuntary recall of flashback memories. Results provided a first replication of a specific pattern of brain activation at the encoding of memories that later returned as flashbacks. This included elevation in the rostral anterior cingulate cortex, insula, thalamus, ventral occipital cortex and left inferior frontal gyrus (during just the encoding of scenes that returned as flashbacks) alongside suppressed activation in the left inferior frontal gyrus (during the encoding of scenes that returned as flashbacks in other participants, but not that individual). Critically, this is also the first study to show the brain activation at the moment of flashback involuntary recall in the scanner. Activation in the middle and superior frontal gyri and the left inferior frontal gyrus was found to be associated with flashback involuntary recall. In the second study, control conditions from 16 behavioural trauma film paradigm experiments were combined (n = 458) to investigate commonly studied factors that may be protective against flashback development. Results indicated that low emotional response to the traumatic film footage was associated with an absence of flashbacks over the following week. The third study used a positive film to consider the emotional valence of the emotion component of the framework. Positive emotional response at the time of viewing the footage was associated with positive involuntary memories over the following week. The fourth study aimed to replicate and extend this finding, comparing the impact of engaging in two cognitive tasks after film viewing (equated for general load). Predictions were not supported and methodological considerations are discussed. Results may have implications for understanding flashbacks and involuntary autobiographical memories occurring in everyday life and across psychological disorders. Further understanding of the proposed components of the clinical neuroscience framework may even help inform targeted treatments to prevent, or lessen, the formation and frequency of distressing involuntary memories.
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Smith, Hannah. "A developmental cognitive neuroscience approach to the investigation of conduct problems and classroom behaviour for learning." Thesis, Goldsmiths College (University of London), 2017. http://research.gold.ac.uk/20630/.
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With a high prevalence of conduct problems (CP) in school-aged children, effective interventions for these youths are of great importance. This thesis considers CP in the context of the classroom, including examinations of executive function (EF) and emotion-related skills; the development and evaluation of a classroom-based intervention to improve behaviours for learning; and an EEG investigation of cognitive control and emotion regulation (ER). The heterogeneous nature of CP is considered throughout, with an examination of the callous-unemotional (CU) traits subtype. In two experimental studies, pupils with CP (with and without CU traits) were found to have deficits in EF and emotion-related skills. Low behavioural and academic self-perceptions and poor student-teacher relationships (STR) were also identified. For the first time, emotion lability/negativity was identified as a mechanism through which CP is associated with student-teacher conflict. A systematic review of intervention outcomes for CU traits indicated generally poorer outcomes for these youths, but demonstrated the potential for behaviour change. Based on this work, a cognitive neuroscience informed intervention for mainstream pupils with CP was developed and evaluated. The intervention yielded mixed results, with poor fidelity from teaching staff possibly accounting for this. Finally, a direct measure of cognitive and emotional control was addressed through a pilot study with adults, using an EEG emotion-induction go/no-go paradigm. A distinct N2 component was found, providing support for this tool as a measure of ER. Self-reported EF and ER were not associated with the N2 response; possible reasons for this are discussed. The results in this thesis advance our understanding of CP in the school context, provide support for the utility of the CU traits distinction, and examine the effectiveness of intervention approaches for these pupils. Furthermore, measurement issues in EF and ER research are highlighted and related to a novel EEG measurement tool.
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Hoon, A. C. "The effect of manipulating the expression of the NR2B subunit of the NMDA receptor on learning and memory." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:eae324a3-873f-4b50-9bcc-8c43b72866a3.
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Overexpression of the NR2B subunit of the NMDA receptor in the forebrain has been shown to improve learning and memory in mice (Tang et al 1999), which provides exciting implications for the enhancement of human cognition. However, it was first essential to establish replicability, and since the Tang et al (1999) study used only male mice we wished to investigate possible sex differences. On the hidden platform watermaze, we found a trend for male NR2BOE mice to learn the task more quickly than male wildtype mice (as observed by Tang et al. 1999), but the opposite trend in female mice; female NR2BOE mice were slower to reach the hidden platform than female wildtype mice. This pattern of results was also observed on the spatial reference Y memory task and open field task (for anxiety), although not on the spatial working memory T maze task (despite a sex difference). However, wildtype and NR2BOE mice performed at similar levels on the novel object recognition task, the spatial novelty preference task, visible platform watermaze and visual discrimination task. A battery of tests considering some species typical behaviours of mice demonstrated that wildtype and NR2BOE mice were comparable on tests of motor ability, strength, co-ordination, anxiety, burrowing and nesting. This suggests that our behavioural results are not due to a general impairment or enhancement of species typical behaviours. We considered the possibility that the difference between the results of Tang et al (1999) and those we observed may be caused by age differences; hence we attempted to replicate our results on the hidden platform watermaze, spatial reference Y maze and open field test in age matched mice. However, the second cohort of NR2BOE mice performed at similar levels to wildtype mice, and at significantly improved levels compared to the mice of the first cohort. We also considered the effects of knocking out the NR2B subunit on learning and memory, and NR1 subunit deletion within the hippocampus. On the spatial working memory T maze, these mouse strains performed similarly to their respective wildtype strains. Similarly, on a two beacon watermaze (with one indicating the platform position), mice lacking the NR2B subunit were able to locate the platform in a similar length of time. To ensure that the null results we had observed in the second cohort were not due to loss of the NR2B protein overexpression in the forebrain, we performed polymerase chain reactions (PCR), quantitative real-time PCR, and Western blots. We ascertained that the transgene was indeed present and that NR2B mRNA and protein levels were elevated in the hippocampi of the NR2BOE mice. In conclusion, it is unclear why the behaviours we observed in the NR2BOE mice are different to those published in the literature. It is possible that they may be due to differences in environmental enrichment, but the cause of the genotype by sex differences observed in the mice of cohort 1 is unclear. Nonetheless, we have advanced our knowledge of the effects of modifications in the levels of the NR2B subunit of the NMDA receptor on learning and behaviour.
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Hunt, Laurence T. "Modelling human decision under risk and uncertainty." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:244ce799-7397-4698-8dac-c8ca5d0b3e28.
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Humans are unique in their ability to flexibly and rapidly adapt their behaviour and select courses of action that lead to future reward. Several ‘component processes’ must be implemented by the human brain in order to facilitate this behaviour. This thesis examines two such components; (i) the neural substrates supporting action selection during value- guided choice using magnetoencephalography (MEG), and (ii) learning the value of environmental stimuli and other people’s actions using functional magnetic resonance imaging (fMRI). In both situations, it is helpful to formally model the underlying component process, as this generates predictions of trial-to-trial variability in the signal from a brain region involved in its implementation. In the case of value-guided action selection, a biophysically realistic implementation of a drift diffusion model is used. Using this model, it is predicted that there are specific times and frequency bands at which correlates of value are seen. Firstly, there are correlates of the overall value of the two presented options, and secondly the difference in value between the options. Both correlates should be observed in the local field potential, which is closely related to the signal measured using MEG. Importantly, the content of these predictions is quite distinct from the function of the model circuit, which is to transform inputs relating to the value of each option into a categorical decision. In the case of social learning, the same reinforcement learning model is used to track both the value of two stimuli that the subject can choose between, and the advice of a confederate who is playing alongside them. As the confederate advice is actually delivered by a computer, it is possible to keep prediction error and learning rate terms for stimuli and advice orthogonal to one another, and so look for neural correlates of both social and non-social learning in the same fMRI data. Correlates of intentional inference are found in a network of brain regions previously implicated in social cognition, notably the dorsomedial prefrontal cortex, the right temporoparietal junction, and the anterior cingulate gyrus.
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Barkus, Christopher. "Studies of emotionality in genetic mouse models of altered glutamate or 5-HT function." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:c144d0d0-ba1f-4127-b07a-372e6abf569b.
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Laatikainen, Linda Maria. "The role of catechol-O-methyltransferase (COMT) in hippocampal function." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:d0c9e1fa-a052-4af7-aaff-00548365e024.
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Catechol-O-methyltransferase (COMT) metabolises catechol-containing compounds, including dopamine. The aim of this thesis was to investigate whether COMT is involved in hippocampal function. This thesis also explored the role of functional polymorphisms within the COMT gene in the pathogenesis of schizophrenia and schizophrenia-related phenotypes. First, as part of a study investigating the role of COMT in schizophrenia, human hippocampal COMT mRNA levels were shown to be neither altered in schizophrenia or bipolar disease, nor affected by COMT genotype. Hence, functional COMT polymorphisms do not appear to operate by altering gross COMT mRNA expression. Importantly, this study showed that COMT is expressed in the human hippocampus. Second, the role of COMT in hippocampal neurochemistry was explored by studying the effect of pharmacological COMT inhibition on catecholamines and metabolites in rat hippocampal homogenates, and extracellularly, using microdialysis. Both demonstrated that COMT modulates hippocampal dopamine metabolism. Thus, hippocampal COMT is of functional significance with respect to dopamine. Third, the effect of COMT inhibition on hippocampus-dependent behaviour was investigated. The results suggested a memory-enhancing effect of pharmacological COMT inhibition on hippocampus-dependent associative and non-associative forms of short-term memory in rats. In contrast, acute COMT inhibition appeared to have no effect on behavioural correlates of ventral hippocampal function i.e. anxiety-like behaviour. In summary, the expression of COMT mRNA in the human hippocampus, as well as the effect of COMT inhibition on rat hippocampal neurochemistry and hippocampus-dependent behaviour provide evidence for a functional role of COMT in the hippocampus. Moreover, changes in COMT activity alter hippocampal dopamine metabolism, which could be a potential mechanism for the role of COMT in hippocampus-dependent short-term memory.
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Colaferro, Claudia Almeida. "A contribuição do neuromarketing para o estudo do comportamento do consumidor." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/12/12139/tde-27012012-185906/.
Full textAbstract:
À medida que se avança no século XXI observamos a diversidade humana, cada vez em maior número, convivendo e interagindo a todo o momento. As dificuldades aumentam quando a diversidade se dá além de diferentes sexos, idades, mas também por diferentes opiniões e as várias formas de expressão e comportamento das pessoas, principalmente aqueles não conscientes. Nesse contexto vive-se o desencadeamento de uma crise das metodologias clássicas de investigação, vistas como limitantes e pouco esclarecedoras para o entendimento de que, em um mesmo indivíduo, podem existir estilos de consumo distintos, não conscientes, além de que o entrevistado pode, de maneira intencional ou não intencional, compreender mal, interpretar mal ou até mesmo enganar o pesquisador. O objetivo da dissertação foi avaliar se o neuromarketing pode ser uma nova área de colaboração ao entendimento do consumidor, ser capaz de obter as informações não declaradas do indivíduo, pela captura das informações cerebrais, adicionando assim conhecimento para o processo do entendimento de seu comportamento de consumo, validando-o como uma nova área de cooperação. Por meio de revisão bibliográfica e pesquisa empírica buscou-se identificar, entender e com isso resumir conceitos básicos sobre o neuromarketing, seu entendimento, suas formas de medição e técnicas, suas contribuições e limitações, preocupações e expectativa de futuro. Como resultado obteve-se que há uma diferença entre o entendimento do público acadêmicos entrevistado sobre neuromarketing versus o que se observa entre os estudos de comportamento do consumidor em práticas no mercado. Essas diferenças vão além das técnicas empregadas no estudo. Encontrou-se uma diversidade de conceitos técnicos, aplicações em marketing, vantagens e limitações, preocupação ética e diferentes visões de futuro. Predominantemente encontra-se um cenário típico de um assunto novo, onde várias opiniões são obtidas e buscou-se elencar as áreas de concordância até o momento. A busca pelo maior conhecimento da mente, transforma-a em um orgão prático, capaz de se moldar para intermináveis autoaperfeiçoamentos. Mas, apesar das imagens da mente carregarem peso de autoridade na ciência, seus significados como input científico são válidos, mas não oferecem ao público a clareza de que podem ser ainda utilizados como suporte imediato. O funcionamento do cérebro não é simples e natural e sim mediado na maneira que se conhece, entende e visualiza os estímulos e também pelo contexto social, político e econômico no qual o indivíduo pertence e convive. Portanto, conclui-se que o neuromarketing é uma aplicação da neurociência para maior entendimento dos comportamentos do consumidor e mais uma alternativa que, como qualquer outra pesquisa de mercado, por si só, não oferecerá um diagnóstico exaustivo para a pergunta do problema. Recomenda-se o uso em conjunto com outras metodologias, sempre levando em conta a particularidade de cada uma, seja pela especificidade da amostra, coleta de dados, análise dos mesmos e as conclusões com as devidas ressalvas, buscando sempre seguir a ética e os detalhes de cada mercado. Como sugestão seria importante contínuas investigações que validem e formem um arcabouço de conhecimento de investigações de comportamento.As the life progress through the twenty-first century we see human diversity in an increasing growth, living and interacting in a faster and higher frequency. The difficulties to understand their behavior increase when the range of variety goes beyond genders, ages, through different opinions and various forms of expression and behavior, especially those of unconscious reasons. In this context one lives up triggering a crisis of classical methodologies of research, seen as limiting and not helpful to the understanding that, in the same individual, there may be distinct styles of consumption, unconscious, and that the interviewee can intentionally or unintentionally, misunderstand, misinterpret, or even mislead the researcher. The aim of this work was to assess whether neuromarketing may be a new area of collaboration to the understanding of the consumer, and by doing so being able to obtain unreported information of the individual by capturing the information in the brain, thereby adding knowledge to the process of understanding your consumer behavior, validating it as a new area of cooperation. Through literature review and empirical research the idea of the stydy was to identify, understand and summarize the knowledge captured from academics and executives from research companies, the basics concepts of neuromarketing, its understanding, its ways of measuring and techniques, its contributions and limitations, and therefore its concerns and expectations of the future. As a result it was found that there is a difference between the academic´s understanding about neuromarketing versus what is observed in studies of consumer behavior in the market practices. These differences go beyond the techniques employed in the study. We found a diversity of technical concepts, applications in marketing, advantages and limitations, ethical concerns and different visions of the future. Predominantly we´ve found a scenario that is typical of a new area of study, where many different opinions are obtained and where we tried to rank the areas of agreement so far. The quest for greater knowledge of the mind, transform it with a body capable of practical shape for endless self-improvement. But despite that the images of the mind carry the weight of authority in science, their scientific input and their meanings are valid, but not a clear offer to the public as to be used as immediate support. The functioning of the brain is not simple and natural but mediated with interferences as the ways it recognizes, understands and visualizes the stimuli and also by the social, political and economic context in which the individual belongs and lives. Therefore we conclude that neuromarketing is an application of neuroscience to better understanding of consumer behavior and another alternative to add to the list of market research, and like any other option, it does not provide by itself a comprehensive assessment of the problem to the question. It is recommended to use neuroscience in its application to consumer in conjunction with other methodologies, always taking into account the particular features of each one, the specificity of the sample, the data collection, the analysis and combination of data from different studies and its conclusions with appropriate caveats, always trying to follow the ethics and details of each market. As a suggestion from this study it would be important to a continue research to validate and form a framework of knowledge of consumer behavioral research, as well as how to combine different areas and data from other sciences.
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Tziortzi, Andri. "Quantitative dopamine imaging in humans using magnetic resonance and positron emission tomography." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:26b8b4c2-0237-4c40-8c84-9ae818a0dabf.
Full textAbstract:
Dopamine is an important neurotransmitter that is involved in several human functions such as reward, cognition, emotions and movement. Abnormalities of the neurotransmitter itself, or the dopamine receptors through which it exerts its actions, contribute to a wide range of psychiatric and neurological disorders such as Parkinson’s disease and schizophrenia. Thus far, despite the great interest and extensive research, the exact role of dopamine and the causalities of dopamine related disorders are not fully understood. Here we have developed multimodal imaging methods, to investigate the release of dopamine and the distribution of the dopamine D2-like receptor family in-vivo in healthy humans. We use the [11C]PHNO PET ligand, which enables exploration of dopamine-related parameters in striatal regions, and for the first time in extrastriatal regions, that are known to be associated with distinctive functions and disorders. Our methods involve robust approaches for the manual and automated delineation of these brain regions, in terms of structural and functional organisation, using information from structural and diffusion MRI images. These data have been combined with [11C]PHNO PET data for quantitative dopamine imaging. Our investigation has revealed the distribution and the relative density of the D3R and D2R sites of the dopamine D2-like receptor family, in healthy humans. In addition, we have demonstrated that the release of dopamine has a functional rather than a structural specificity and that the relative densities of the D3R and D2R sites do not drive this specificity. We have also shown that the dopamine D3R receptor is primarily distributed in regions that have a central role in reward and addiction. A finding that supports theories that assigns a primarily limbic role to the D3R.
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Browncross, Helen Anna. "The role of the primate frontopolar cortex in mnemonic and choice behaviour." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:2807879b-e535-474c-b884-fa4c3c5296ab.
Full textAbstract:
The role of the primate frontopolar cortex (FPC) has been investigated using human neuroimaging, lesion and disruption techniques. The results of these investigations have led to a variety of theories regarding the function of this region. It has been linked to the formation of task sets, the performance of multiple tasks, reasoning, context-specific memory (including episodic memory, prospective memory and source memory), attention to internally or externally generated information, mentalising and decision-making. It has not previously been possible to study this area using animal lesion techniques. Here, behavioural experiments conducted using non-human primates (rhesus macaque monkeys) who have received lesions to the frontal pole investigate the contribution of this region to context-specific memory, decision-making and social cognition. Functional magnetic resonance imaging (fMRI) is used to investigate changes in functional network connectivity which occur after lesions to this region. A long-lasting impairment is observed in contextual memory judgements (specifically, how recently a stimulus was encountered) after lesions to the frontal pole. An analysis of the influence of the outcomes of previous choices on behaviour on an analogue to the Wisconsin Card Sorting Test (WCST) indicate that monkeys with lesions to area 10 may be less influenced by the outcomes of an extended history of rewards than control animals. Long-lasting widespread disruption to functional networks after lesions to this region indicate that indirect anatomical connections from this region to posterior areas play a crucial role in the normal functioning of posterior networks.
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Wolff, Nicole, Veit Roessner, and Christian Beste. "Behavioral and neurophysiological evidence for increased cognitive flexibility in late childhood." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-220139.
Full textAbstract:
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.
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Witek, Maria. "'... and I feel good!' : the relationship between body-movement, pleasure and groove in music." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:a4036764-bc54-44ad-8015-f635ab6dca97.
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In many musical cultures, people synchronise their bodies to the rhythmic patterns of the music, and such embodied engagements are one of the most overtly enjoyable forms of musical appreciation. However, the ways in which rhythmic structure, body-movement and pleasure are related remains unclear. The present thesis directs a broadly psychological, yet multi-methodological and interdisciplinary, approach towards this relationship, centring on the rhythmic structure of syncopation in groove-based funk music. Through perceptual experiments, computational modelling, rating surveys, neuroimaging and motion-capture recording, syncopation was found to relate, in primarily negatively linear and inverted U-shaped ways, to finger-tapping performance, perceptions of stability, subjective desire to move and feelings of pleasure, neural activity in motor and reward areas, and force, synchrony and periodicity in body-movements. These relationships also depended on individuals’ musical training, dancing experience and groove familiarity. Ecological and embodied theories of perception and a phenomenology of groove provide a backdrop to the empirical findings, on the basis of which it is suggested that the different relationships between syncopation in groove and perceptual, subjective, neural and corporeal attributes interact in reciprocal ways. It is proposed that syncopation invites the body to physically enact the musical structure and directly participate in the rhythms of groove, due to the perceptual tension and ‘open spaces’ afforded by the perception of metric events in syncopation. In groove, body, mind and music extend into each other and this distributed musical process has affective significance. Since the physical pleasures of dancing to music are such a historically and culturally ubiquitous phenomenon, the empirical findings and theoretical proposals of this thesis make significant contributions towards a much-needed coupling of affective and embodied theories of music.
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Dhawan, Sandeep Sonny. "Learning to focus and focusing to learn : more than a cortical trick." Thesis, University of St Andrews, 2018. http://hdl.handle.net/10023/15883.
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The consequence of many psychiatric and neurodegenerative disorders, such as Parkinson's disease and schizophrenia, is an impairment in ‘executive functioning'; an umbrella term for several cognitive processes, including the focussing and shifting of attention and the inhibition of responding. The ability to form an ‘attentional set' involves learning to discriminate qualities of a multidimensional cue, and to subsequently learn which quality is relevant, and therefore predictive of reward. According to recent research, the subthalamic nucleus (STN) and possibly the adjacent zona incerta (ZI) may mediate the formation of attentional set. Dysregulation of the STN as a result of Parkinson's disease contributes to characteristic motor symptoms, and whilst deep-brain stimulation of this region may treat gross motor impairments, it may also impair cognition. The work in this thesis aimed to expand our understanding of the mechanisms of attentional set-formation, and the role of the STN in this process. This thesis evaluates new methods for examining set-formation in the attentional set-shifting task; rather than inferring this behaviour solely from the cost of shifting set, modifications to the task design in Chapters 3 & 4 explored several hypotheses designed to exploit a deficit in this behaviour. Chapter 6 revealed that inhibition of this region with designer receptors leads to a disruption in attentional selectivity, which compromises the ability to form an attentional set. This manifested as an inability to parse relevant information from irrelevant, and instead, animals learned the stimuli holistically. The findings in this thesis also suggested that reversal and attentional shifting processes do not operate independently, but rather in a hierarchy, and that consequently, the STN is a region that may be crucial in selecting appropriate responses during associative learning that leads to the formation of an attentional set.
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Menassa, David Antoine. "Magnetoencephalography and neuropathological studies of autism spectrum disorders and the comorbidity with epilepsy." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:e809ac19-1f3c-4ef9-83db-69950ab65994.
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Autism spectrum disorders (ASD) are neurodevelopmental disorders with multiple neurobiological aetiologies, which could be genetic, structural, metabolic or immune-mediated. ASDs are diagnosed with deficits in social communication and restricted and repetitive behaviours, and are associated with sensorial atypicalities. 30% of cases have co-existing epilepsy. A series of in vitro, in vivo and post-mortem investigations were undertaken to examine sensory atypicalities in ASD. In vitro characterisation of hippocampal neuronal cultures using immunofluorescence demonstrated the presence of multiple cell types including neurons, astrocytes and microglia. The distribution of ion channels of the Shaker family and tumour necrosis factor α receptors in astrocytes and neurons were identified but not explored further. Neuroanatomical and neuropathological investigations of primary olfactory cortex, using post-mortem stereology, demonstrated a specific increase in glial cell densities in layer II, which was negatively associated with age in ASD. Increases in glia were also associated with symptom severity and often co-localised with the presence of corpora amylacea in layer I. Qualitative analysis of the olfactory tubercle demonstrated that corpora amylacea did not extend to this neighbouring region of the primary olfactory cortex in ASD. These changes were independent of co-existing epilepsy and not observed in epilepsy without ASD. Preliminary pilot studies of the hippocampus provided a stereological sampling strategy to quantify cell densities in future investigations of this area in ASD. Neurophysiological investigations using collected magnetoencephalography data demonstrated diminished occipital gamma oscillatory synchrony in ASD in a visual time perception task. This did not always predict behavioural outcome but was specific to ASD and could not be explained simply in terms of changes in task performance. Moreover, changes in oscillatory synchrony were associated with symptom severity. These observations in primary sensory domains in post-mortem tissue and in patients suggest possible novel mechanisms in ASD and extend knowledge of the neurobiological bases of these disorders.
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Wolff, Nicole, Veit Roessner, and Christian Beste. "Behavioral and neurophysiological evidence for increased cognitive flexibility in late childhood." Nature Publishing Group, 2016. https://tud.qucosa.de/id/qucosa%3A30196.
Full textAbstract:
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.
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Ogbeide-Latario, Oghomwen. "The Role of Slow-Wave-Sleep in Hippocampus-Dependent Memory in Aging and Alzheimer's Disease." eScholarship@UMMS, 2021. https://escholarship.umassmed.edu/gsbs_diss/1136.
Full textAbstract:
Aging and Alzheimer’s disease (AD), are associated with disabling sleep and cognitive deficits. Specifically, aging and Alzheimer’s disease is associated with reduced quantity and quality of the deepest stage of sleep, called slow-wave-sleep (SWS). Interestingly, SWS has been implicated in hippocampus-dependent memory in mice. More importantly, sleep deprivation, aging, and AD are all associated with deficits in memory. Therefore, I hypothesize that, in aging and AD, the sleep deficits are, at least in part, responsible for memory impairments and increasing the quantity and quality of SWS will reverse these memory deficits.
I first developed mouse models of SWS enhancement in aging and AD. Chemogenetic activation of the parafacial zone GABAergic neurons enhances SWS in aged mice as previously described in adult mice. Similarly, in AD mice, SWS enhancement is as effective as in littermate wild-type controls. Then, I used these mouse models to characterize the role of SWS in memory using novel gain-of-sleep experiments. I found that acute SWS enhancement: 1) reduce spatial memory in adult mice and 2) failed to improve spatial memory in aged mice. In a preliminary study, acute SWS enhancement seems to improve contextual memory in AD mice.
Collectively, my work provides a novel mouse model of SWS enhancement in aging and AD, offering a pivotal tool to study the role of SWS in physiological functions and neurodegenerative diseases. Furthermore, my results suggest that acute SWS enhancement does not benefit the behavioral manifestation of memory consolidation in adult mice and aged mice.
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Byrom, Nicola. "Towards an understanding of the role of associative learning in risk for mental health problems." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:2d566024-1215-49e3-b1d6-666a8f99838b.
Full textAbstract:
The ability to prioritize information enables us to think and take action without being overwhelmed by external stimuli or internal thoughts and feelings. Neuroticism is associated with altered processing of emotional information but differences in the processing of emotional information may arise from basic differences in information processing, such as altered processes of attention, changes in sensitivity to salient information, or differences in the ability to encode conjunctions of information. Through this thesis, I explore the relationship between neuroticism and processing of non-emotional information, with a particular focus on learning about combinations of information. Associative learning paradigms were used to test ability to learn about combinations of information and neuroticism was observed to be associated with strong non-linear discrimination learning. The tendency to focus on specific details was associated with weak non-linear discrimination learning. A novel model of associative learning is presented, offering an account for how variation in the ability to engage in non-linear discrimination learning might be understood. Mechanisms underlying the association between neuroticism and strong non-linear discrimination learning were explored. Neuroticism was not found to be associated with a tendency to focus on specific details or shifts in attention towards goal relevant information. Neuroticism was not found to be associated with enhanced ability to identify feature conjunctions, altered sensitivity to the relative validity of stimuli or pre-exposure of stimuli. The importance of understanding individual differences in processes of associative and the value of associative learning tasks to look at information processing biases underlying neuroticism are discussed.
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Vetter, Nora C., Julius Steding, Sarah Jurk, Stephan Ripke, Eva Mennigen, and Michael N. Smolka. "Reliability in adolescent fMRI within two years – a comparison of three tasks." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-230621.
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Longitudinal developmental fMRI studies just recently began to focus on within-subject reliability using the intraclass coefficient (ICC). It remains largely unclear which degree of reliability can be achieved in developmental studies and whether this depends on the type of task used. Therefore, we aimed to systematically investigate the reliability of three well-classified tasks: an emotional attention, a cognitive control, and an intertemporal choice paradigm. We hypothesized to find higher reliability in the cognitive task than in the emotional or reward-related task. 104 healthy mid-adolescents were scanned at age 14 and again at age 16 within M = 1.8 years using the same paradigms, scanner, and scanning protocols. Overall, we found both variability and stability (i.e. poor to excellent ICCs) depending largely on the region of interest (ROI) and task. Contrary to our hypothesis, whole brain reliability was fair for the cognitive control task but good for the emotional attention and intertemporal choice task. Subcortical ROIs (ventral striatum, amygdala) resulted in lower ICCs than visual ROIs. Current results add to the yet sparse overall ICC literature in both developing samples and adults. This study shows that analyses of stability, i.e. reliability, are helpful benchmarks for longitudinal studies and their implications for adolescent development.
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Rohenkohl, Gustavo. "Cognitive neuroscience, experimental psychology." Thesis, University of Oxford, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.547508.
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Turkington, Douglas. "Cognitive-behavioural therapy (CBT) for schizophrenia." Thesis, University of Newcastle upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271209.
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Aquan-Assee, Jasmin Soylin Elizabeth. "Induced pain : cognitive and behavioural correlates." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28574.
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Cognitive processes have recently received considerable attention in studies of pain. Belief systems, coping mechanisms, perceptions of control and self-efficacy, and other cognitive systems appear to play a central role in determining individual differences to painful events (Rollman, 1983; Turk, Meichenbaum & Genest, 1983; Weisenberg, 1984). The present investigation sought to examine the cognitive and behavioural relationships that are associated with individual differences in responses to painful stimuli. Sixty female undergraduate psychology students participated in the experimental pain induction procedure which used the cold pressor test as the noxious stimulation. To gain a broad assessment of the different factors that may be characteristic of differences in response to pain, tolerant subjects were contrasted with less tolerant subjects on a variety of self-report, cognitive and behavioural - facial expression - measures. As part of the assessment procedure, subjects completed measures of state anxiety, self-efficacy to withstand pain, and a questionnaire involving a retrospective analysis of cognitive techniques. Half of the subjects were interviewed regarding their cognitions concerning the cold pressor task both pre and post their immersion, and the other half were interviewed post only. Transcriptions were coded independently of pain tolerance status. Subjects' facial expressions were videotaped during the cold pressor task and coded using the Facial Action Coding System (FACS) developed by Ekman and Friesen (1978).
It was hypothesized that dysfunctional cognitions, lack of effective coping activity, amplification of sensory intensity and affective discomfort and high levels of facial activity would characterize subjects who were less tolerant of the induced pain.
The distribution of the endurance times to the cold pressor task confirmed past observations that subjects cluster into two major groups of high and low tolerance (Turk et al. 1983). The results confirmed the major hypotheses that there are cognitive and self-report differences between pain tolerance groups. In comparison to tolerant subjects, less tolerant subjects had lower scores of perceived self-efficacy to withstand pain, higher scores for both sensation and discomfort ratings, retrospectively reported having experienced more pain, and made more accurate estimates of their duration in the cold water. Less tolerant subjects also reported more dysfunctional cognitions during the cold pressor task and reported using effective coping techniques to a lesser extent than tolerant subjects. Major differences between the tolerance groups also appeared in the length of post-test interviews. Tolerant subjects had much lengthier interviews at the post-test than less tolerant subjects. A discriminant analysis revealed that self-efficacy beliefs during the experimental task and the length of the post-test interviews were the most important discriminators between the groups. These results highlight the role of cognition in individual differences in pain tolerance. These results also suggest that low pain tolerance subjects may be better conceptualized as being ineffective and overwhelmed in their attempts to cope with pain which supports the current notion that cognitive based therapies may be the key in managing and alleviating pain states. No support was found for the hypothesis that subjects of differing pain tolerance thresholds would be characterized by differences in facial activity. Facial actions associated with pain in the present study were similar with facial expressions in previous studies (cf. Craig & Patrick, 1985; Hyde, 1986; Swalm, 1987). Contrary to previous results (Craig & Patrick, 1985), measures of facial expression increased over exposure time similarly to self-report. High levels of facial expression were associated with low levels of self-report of coping cognitions assessed at the post-test and with shorter post-test interviews.Arts, Faculty of
Psychology, Department of
Graduate
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Farrelly, Robert. "Clients experinces of cognitive behavioural therapy." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531832.
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Williams, Clare Anne. "Belief change in cognitive-behavioural therapy." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326777.
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Germond, Sean Alan. "Rheumatoid arthritis : a cognitive-behavioural intervention." Master's thesis, University of Cape Town, 1991. http://hdl.handle.net/11427/13551.
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Bibliography: leaves 190-206.This study investigated both the mediating role of psychological adjustment in determining pain experience, disease · status, and immune function in Rheumatoid Arthritis (RA), and the value of cognitive-behavioural intervention in improving the overall health status of such patients. Two related hypotheses were tested in a matched-random assigned two-groups design, with pre-, mid-, and post-intervention assessment. Fourteen (N = 14) female RA outpatients, selected along established inclusion criteria, were allocated to either treatment (n=8) or control (n=6) groups after being matched on date of disease onset and ratings, of coping efficacy. The treatment group received an eight week Stress Inoculation and Pain Management Training programme (sixteen 2-hour sessions) based on the conceptual approach of Meichenbaum (1985) and adopted from a program by O'Leary, Shoor, Lorig and Holman (1988). The program included educational material, instruction in palliative and cognitive pain management strategies and the application thereof in daily living, goal setting to improve activity function, and group discussion. The program was designed to nurture and develop existing coping skills, and to impart new strategies to cope with daily stress and pain. Pre-intervention correlational analyses tested the extent to which mood disturbance, self-perceptions of coping efficacy, health locus of control and stressful life experience were related to intensity and quality of pain, disease activity, functional status and lymphocyte proliferation rate. Intra- and inter-group analyses were conducted to determine treatment effects in terms of change scores .on the dependent measures, and case studies were conducted to evaluate individual response both to disease and cognitive-behavioural intervention.
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Lymperopoulou, Ioana Anca. "A cognitive neuroscience perspective of emotions." Thesis, Högskolan i Skövde, Institutionen för biovetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-11364.
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Emotions have a remarkable capacity to mobilize an individual and shape a person’s behavior in order to ultimately lead to a higher wellbeing. The importance of emotions is further emphasized by pathological cases of people who suffer from an inability to normally regulate their emotional life, such as people who suffer from major depression disorder (MDD), eating disorders, or borderline personality disorder. Given the central role emotions play in our lives, it is very easy to understand the great interest cognitive neuroscientists have in this research field. Emotions have been approached in the last decades from different angles and as such, distinct theories arose. The goal of this study is to give a comprehensive overview of the emotion theories that exist, with a focus on three of the fastest developing cognitive theories of emotions: Frijda’s action-readiness, Russell’s core affect and the communicative theory. Additionally, the neural correlates of emotions will be discussed, focusing on the role of amygdala in the negative emotion of fear. Neuroimaging studies that reveal a correlation between the amygdala and emotions, fear in particular, will be described. Given that the ability of self-regulation is crucial for the achievements of our aims and goals, fMRI studies designed to investigate neural the underpinnings of emotion regulation will be presented. The process of cognitive reappraisal will be used to point towards the brain regions that act as down-regulators for the activity of amygdala while processing negatively valenced stimuli.
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Contreras, Juan Manuel. "A Cognitive Neuroscience of Social Groups." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:10882.
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We used functional magnetic resonance imaging to investigate how the human brain processes information about social groups in three domains. Study 1: Semantic knowledge. Participants were scanned while they answered questions about their knowledge of both social categories and non-social categories like object groups and species of nonhuman animals. Brain regions previously identified in processing semantic information are more robustly engaged by nonsocial semantics than stereotypes. In contrast, stereotypes elicit greater activity in brain regions implicated in social cognition. These results suggest that stereotypes should be considered distinct from other forms of semantic knowledge. Study 2: Theory of mind. Participants were scanned while they answered questions about the mental states and physical attributes of individual people and groups. Regions previously associated with mentalizing about individuals were also robustly responsive to judgments of groups. However, multivariate searchlight analysis revealed that several of these regions showed distinct multivoxel patterns of response to groups and individual people. These findings suggest that perceivers mentalize about groups in a manner qualitatively similar to mentalizing about individual people, but that the brain nevertheless maintains important distinctions between the representations of such entities. Study 3: Social categorization. Participants were scanned while they categorized the sex and race of unfamiliar Black men, Black women, White men, and White women. Multivariate pattern analysis revealed that multivoxel patterns in FFA--but not other face-selective brain regions, other category-selective brain regions, or early visual cortex--differentiated faces by sex and race. Specifically, patterns of voxel-based responses were more similar between individuals of the same sex than between men and women, and between individuals of the same race than between Black and White individuals. These results suggest that FFA represents the sex and race of faces. Together, these three studies contribute to a growing cognitive neuroscience of social groups.Psychology
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Buda, Marie. "The cognitive neuroscience of reality monitoring." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648292.
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Carlsson, Veronica. "Emotional attention : A cognitive neuroscience perspective." Thesis, Högskolan i Skövde, Institutionen för biovetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-16258.
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Attention is a cognitive mechanism that guides our perception in order to prioritize the limited resources to the most relevant information while ignoring distracting information. Attention can be voluntarily deployed to stimuli during tasks or goals, or the features of the stimulus can capture our attention either by being salient or being emotionally induced. Emotions affect multiple different cognitive processes such as attention because emotional stimuli can be relevant for defending or sustain life. This relationship between attention and emotion indicates that there should be interactive but distinct networks between these cognitive mechanisms as well as a modulative effect on perceptional and attentional systems. Emotions were in general demonstrating a facilitation affect on attentional and saccadic processes as well as broadening or narrowing the scope of attention. The reason behind emotions impact on attention was proposed to be for eliciting a change in the application of resources in order to solve the limited capacity problem and possibly to protect and sustain life. Inconsistent findings as well as limitations for emotional attention studies are discussed.
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Gehring, Tiago V. "Automated classification of behavioural and electrophysiological data in neuroscience." Thesis, University of Sheffield, 2018. http://etheses.whiterose.ac.uk/20932/.
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Due to technological advances the amount of data that can be collected in modern science is increasing every day and neuroscience is no exception. Integrating large amounts of data at different spatial and temporal scales is essential for uncovering the underlying mechanisms of the brain but poses also new challenges since drawing conclusions from vast amounts of data is increasingly difficult. New automated and fast analysis methods that can make sense of large and complex data sets are therefore in need and will become increasingly important in the years and decades ahead. This work proposes new tools for the analysis of two important types of data commonly found in neuroscience. The first is behavioural data from rodent navigation tasks in the form of animal movement paths. Two novel classification methods based on machine learning algorithms are proposed here. The methods are able to automatically or semi-automatically reduce the complex movement paths of the animals to a series of stereotypical types of behaviour, leading toboth more detailed and consistent results. The second type of data considered here is electrophysiological data, in the form of extracellular multielectrode array (MEA) recordings which can record the electrical activity of thousands of neurons in parallel over long periods of time. Here a new highly-parallel data processing tool which can reduce the MEA data to a series of spike trains is presented. The tool can serve as basis for more sophisticated analyses like the reconstruction of the individual cell spike trains, for which machine learning methods are again essential. The results presented here show that machine learning algorithms and parallel processing architectures are both fundamental tools for coping with large and complex data sets, like the ones found in modern neuroscience.
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Christou, Antonios I. "Neurophysiological, behavioural and genetic markers of behavioural problems in early childhood." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6636/.
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The work presented in the present thesis investigated the neural, behavioural and genetic markers that may be associated with the manifestation of behavioural problems during the early years of life. Across four different empirical studies, and by incorporating, behavioural, neurophysiological and genetic investigations, it was demonstrated that: (1) there are neurophysiological signatures that may be associated with the manifestation of behavioural problems early in life; (2) common genetic variations that determine serotonin variability are strongly associated with affectivity-related patterns of frontal brain activation; and that (3) normal genetic variations that modulate serotonin availability and neuroplasticity are each associated with affectivity-related patterns of visual scanning behaviours in response to faces and aversive scenes. Taken together, the results illustrate the existence of robust neural, genetic and behavioural markers that may be associated with the manifestation of behavioural problems in early childhood and prompt further investigation of the area by generating novel hypotheses. Together, the empirical findings of the thesis provide a first stage contribution to the complex mechanisms that may yield risk and resilience for behavioural problems during the early years of life by generating a more comprehensive insight on the field of affectivity.
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Rimes, Katharine Amber. "Cognitive and behavioural processes in health anxiety." Thesis, University of Oxford, 1996. http://ora.ox.ac.uk/objects/uuid:249d20d8-b7c9-47a0-b207-3752105ac52e.
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In this thesis a cognitive-behavioural model of health anxiety is used to investigate the psychological effects of bone densitometry, a health test which can provide an indication of future risk for osteoporosis. The cognitive-behavioural model of health anxiety proposes that people will experience relatively high levels of anxiety about their health if they have a tendency to make particularly negative interpretations of bodily variations and information which may be relevant to health. It was therefore predicted that people who have a pre-existing tendency to worry about their health would react more negatively to the results of bone density measurement. Consistent with this prediction, after a low bone density ("high risk") result, women who reported high levels of pre-existing health anxiety gave higher ratings of anxiety about osteoporosis and perceived likelihood of developing osteoporosis in the near future than women with low levels of preexisting health anxiety. (The two groups did not differ significantly in these ratings before the scan). Differences in the reactions of women with high and low levels of pre-existing health anxiety were still apparent 14 months after the scan. Women receiving a low bone density ("high risk") result showed a "minimization" of the seriousness of low bone density; when individual differences were investigated, it was found that women with very high levels of pre-existing health anxiety did not show minimization. Furthermore, after a "low risk" result, women with high levels of health anxiety were only temporarily reassured. It thus appears that the new measure of health anxiety which was used in this thesis may be useful in helping to identify people who are vulnerable to experiencing distress after health screening. More specific pre-scan measures of beliefs about osteoporosis (derived from the cognitive-behavioural model) also predicted reactions to bone density screening. For example, pre-scan beliefs about the seriousness or burden of low bone density / osteoporosis were stronger predictors of anxiety about osteoporosis three months after the scan than the actual scan result. Factors such as the type of interpretation the woman makes of her scan result, and whether the woman is having her first or second scan, were also found to influence psychological reactions.
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Morland, Rebecca. "Expanding the cognitive behavioural perspective of psychosis." Thesis, City University London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434594.
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Jenkins, Hannah. "An exploration of cognitive behavioural therapy training." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/104375/.
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This thesis contains an exploration of Cognitive Behavioural Therapy (CBT) training. Paper one consists of a systematic review of 13 studies exploring the experience of CBT training. Findings were categorised into four themes; the exploration of Self-practice/Self-reflection, internal processes throughout CBT training, perceived effective components of CBT training, and general satisfaction with CBT training. Overall the findings concluded that CBT training is experienced in a relatively positive way, however, the journey can be difficult for students at times. The review revealed a clear gap in the literature regarding the general experience of CBT training, with no imposed focuses or pre-conceived themes. Implications for students, training course providers and commissioners are discussed. Paper two describes an empirical study conducted on eight students pre and post their postgraduate Diploma in CBT. Personal construct theory and the repertory grid technique were employed to capture students’ experience of training and their construal of their personal and professional development. Findings reported that whilst participants construed themselves as closer to ‘desirable’ elements post training, these differences were not statistically significant. A statistical difference was observed however, in participants’ perception of an ‘Ideal therapist’ post training. Implications for CBT training programmes are discussed and findings related to the political context both in Wales and the rest of the UK. Paper three presents a critical reflection and evaluation of the first two papers, including the authors’ personal reflections on the research process overall and her own experience of postgraduate, professional training in Clinical Psychology.
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Svensson, Idor. "Phonological dyslexia : cognitive, behavioural and hereditary aspects /." [Göteborg] : Dept. of Psychology, Göteborg University, 2003. http://catalogue.bnf.fr/ark:/12148/cb399169814.
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Howell, Rebecca. "Behavioural and neurophysiological consequences of paternal separation in «Peromyscus californicus»." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116993.
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Parental care during the postnatal period has a major role in emotional development of the offspring. In the biparental species, the California mouse (Peromyscus californicus), both the father and the mother have a highly participative role in the postnatal care of pups. Previous studies have shown that if the father is removed, the mother does not compensate for his absence, thus the pups are deficient in care. Here we present results obtained after evaluating the emotional behavior and serotonin (5-HT) neurotransmission of adult California mice after father separation. Pairs of California mice were used for breeding and on postnatal day (PND) 3, litters were randomly designated to either be left with only the mother (paternally separated, PS) or with both parents (control, CTRL). Mice were weaned at PND 30 and after PND 70, behavioral tests were conducted including the open field, elevated plus maze, and novelty suppressed feeding tests. In vivo single unit extracellular recordings were performed in the dorsal raphe nucleus to assess 5-HT neuronal firing activity.According to our results, the absence of the father during the postnatal period does not affect the behavioral response of adult California mice in the open field, although interestingly in these tests these animals display high levels of activity. PS animals display less time in the open arms of the elevated plus maze (F(1,62)=3.93, p=0.052) and have a higher latency to eat in a novel environment after food deprivation (F(1,57)=3.999, p=0.05). While these last two results could be interpreted as an increase of anxiety-like behaviors, PS animals also had decreased food consumption in their home cage (F(1,57)=5.404, p=0.024), which raises questions of whether their latency to eat was due to anxiety, or that they were not as hungry. PS seems to have an impact in the 5-HT firing activity of the dorsal raphe nucleus. Compared with CTRL, in PS animals the mean 5-HT firing rate was decreased (F(1,120) = 5.017, p = 0.027), and the number of neurons per track was also decreased (F(1,39)=6.087, p=0.018). Our results suggest the absence of the father in a bi-parental species, such as California mice, could induce a slight increase in anxiety-like behaviors in response to stressful situations and decreased 5-HT neurotransmission in adulthood.Le soin parental durant la période post-natale joue un rôle majeur dans le développement affectif des rejetons. Pour les espèces biparentales, les souris de Californie (Peromyscus californicus), le père et la mère ont une grande participation dans le soin post-natal chez les souriceaux. Des études antérieures avaient démontré que si on retire le père, la mère ne compensera pas pour son absence, du fait, les rejetons recevront des soins incomplets. Ici, nous présentons les résultats obtenus après avoir évalué le comportement affectif et la neurotransmission de sérotonine (5-HT) chez la souris de Californie adulte après la séparation du père. Des couples de souris de Californie ont été utilisées pour s'accoupler et au jour post-natal (JPN) 3, les rejetons étaient assignés aléatoirement soit à rester seulement avec la mère (séparation paternelle, SP) soit avec les deux parents (témoin, TMN). Les souris ont été sevrées au JPN 30 et après JPN 70, des tests de comportements ont été conduits incluant le test sur terrain libre, du labyrinthe surélevé, et de suppression alimentaire. Des enregistrements extracellulaires simple in vivo a été fait dans le noyau du raphé dorsal pour évaluer les sécrétions neuronales de la 5-HT. D'après nos résultats, l'absence du père durant la période post-natale n'affecte pas le comportement réactionnel chez la souris de Californie adulte sur le terrain libre, bien que, d'un fait intéressant, dans ce test, ces animaux démontrent un plus haut niveau d'activité. Les animaux SP ont passé moins de temps dans les bras ouvert du labyrinthe surélevé (F(1,62)=3.93, p=0.052) et ont un plus long temps d'attente à manger dans un nouvel environnement après privation de nourriture (F(1,57)=3.999, p=0.05). Alors que ces deux derniers résultats peuvent être interprétés par l'augmentation de comportements de simili-anxiété, les animaux SP ont aussi une diminution de la consommation de nourriture dans leur cage personelle (F(1,57)=5.404, p=0.024), ce qui soulève des questions au fait de si leur délai à manger est causé par l'anxiété ou parce qu'ils n'ont pas faim. SP démontre un inclinaison a avoir un effet dans la décharge de 5-HT au noyau dorsal de raphé. Comparé au TMN, les animaux SP en moyenne ont un taux de décharge de 5-HT diminué (F(1,120) = 5.017, p = 0.027), et le nombre de neurones par piste est aussi diminué (F(1,39)=6.087, p=0.018). Nos résultats suggèrent que l'absence du père chez une espèce biparentale, tel que les souris de Californie, peut introduire une légère hausse dans les comportements de simili-anxiété en réponse aux situations stressantes et une diminution de la neurotransmission de la 5-HT à l'âge adulte.
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Davies, Leon Nicholas. "Behavioural correlates of ocular accommodation and the autonomic nervous system." Thesis, Aston University, 2004. http://publications.aston.ac.uk/14539/.
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The binding issue of th is thesis was the examination of workload, induced by relinotopic and spatiotopic stimuli, on both the ocu lomotor and cardiovascular systems together with investigating the covariation between the two systems - the 'eye-heart' link. Further, the influence of refractive error on ocular accommodation and cardiovascular function was assessed. A clinical evaluation was undertaken to assess the newly available open-view infrared Shin-Nippon NVision-K 5001 optometer, its benefit being the capability to measure through pupils = 2.3 mm. Measurements of refractive error taken with the NVision-K were found to be both accurate (Difference in Mean Spherical Equivalent: 0.14 ± 0.35 D; p = 0.67) and repeatable when compared to non-cycloplegic subjective refraction. Due to technical difficulties, however, the NVision-K could not be used for the purpose of the thesis, as such, measures of accommodation were taken using the continuously recording Shin-Nippon SRW-5000 openview infrared optometer, coupled with a piezo-electric finger pulse transducer to measure pulse. Heart rate variability (HRV) was spectrally analysed to determine the systemic sympathetic and parasympathetic components of the autonomic nervous system (ANS). A large sample (n = 60), cross-sectional study showed late-onset myopes (LOMs) display less accurate responses when compared to other refractive groups at high accommodative demand levels (3 .0 0 and 4.0D). Tonic accommodation (TA) was highest in the hypermetropes, fo llowed by emmetropes and early-onset myopes while the LOM subjects demonstrated statistically significant lower levels of TA. The root-meansquare (RMS) value of the accommodative response was shown to amplify with increased levels of accommodative demand. Changes in refractive error only became significant between groups at higher demand levels (3.0 D and 4.0 D) with the LOMs showing the largest magnification in oscilIations. Examination of the stimulus-response cross-over point with the unit ratio line and TA showed a correlation between the two (r = 0.45, p = 0.001), where TA is approximately twice the dioptric value of the stimulus-response cross-over point. Investigation of the relationship between ocular accommodation and systemic ANS function demonstrated covariation between the systems. Subjects with a faster heart rate (lower heart period) tended to have a higher TA value (r = -0.27, p < 0.05). Further, an increase in accommodative demand accompanies a faster heart rate. The influence of refractive error on the cardiovascular response to changes in accommodative demand, however, was equivocal. Examination of the microfluctuations ofacconunodation demonstrated a correlation between the temporal frequency location of the accommodative high Frequency component (HFC) and the arterial pulse frequency. The correlation was present at a range of accommodative demands from 0.0 D to 4.0 D and in all four refractive groups, suggesting that the HFC was augmented by physiological factors. Examination of the effect of visual cognition on ocular accommodation and the ANS confirmed that increasing levels of cognition affect the accommodative mechanism. The accommodative response shifted away from the subject at both near and far. This shift in accommodative response accompanied a decay in the systemic parasympathetic innervation to the heart. Differences between refractive groups also existed with LOMs showing less accurate responses compared to emmetropes. This disparity, however, appeared to be augmented by the systemic sympathetic nervous system. The investigations discussed explored Ihe role of oculomotor and cardiovascular fu nction in workload enviromnents, providing evidence for a behavioural link between the cardiovascular and oculomotor systems.
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Borragan, Pedraz Guillermo. "Behavioural bases and functional dynamics of cognitive fatigue." Doctoral thesis, Universite Libre de Bruxelles, 2016. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/237311.
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La fatigue cognitive représente un phénomène auquel nous sommes tous familiers. Nous en faisons quotidiennement l'expérience, celle-ci étant associée à une réduction de productivité, une augmentation de risques professionnels et une diminution de notre qualité de vie. Malgré l’importance sociétale de ces implications, qui ont fait de l'étude de la fatigue cognitive une de plus investiguées dans le domaine des sciences cognitives, il subsiste un manque de vision commune ainsi qu'une théorie unifiée de la fatigue cognitive, déterminant son origine et ses fonctions, tandis que son caractère stochastique continue à diviser le milieu scientifique. La présente dissertation présente une approche multimodale combinant des données comportementaux et de neuroimagerie spectroscopie proche infrarouge (fNIRS) pour investiguer les facteurs à l’origine du déclenchement du phénomène ainsi que les dynamiques cérébrales associées. Nos résultats suggèrent que la fatigue cognitive ressentie associée à la chute de performance est une fonction de la charge cognitive définie par le Time Based Shared Resources Model (TBRS). Au niveau neural, nous discutons la présence des systèmes de compensation et les changements de connectivité cérébrale dans ce déclenchement. et comment les possibles mécanismes responsables de la maintenance de performance durant des demandes attentionnelles soutenues y sont associées.Doctorat en Sciences psychologiques et de l'éducation
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Lindblom, Jon. "Technihil : the cultural import of cognitive neuroscience." Thesis, Goldsmiths College (University of London), 2016. http://research.gold.ac.uk/19472/.
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The thesis aims to speculate on the implications of neuroscientific resources on aesthetics and cultural production by drawing upon conceptual material provided by ‘90s and recent accelerationist theory and speculative philosophy. Following the work of Ray Brassier, it sees a plethora of untapped potencies in the objective image of cognition unveiled by modern neuroscience – which is contrasted with the anti-scientific stance concomitant with much Continental philosophy and critical theory. Focusing primarily on the registers of embodiment and experience in recent forms of corporeal phenomenology and affect theory, it is argued that their intellectual advocates generally share a commitment to the unobjectifiable nature of so-called ‘embodied’, or ‘lived’, experience which does not sit well with the neuroscientific project of objectification. Instead, the thesis utilizes Thomas Metzinger’s PSM-theory of selfhood and Brassier’s work on the speculative implications of nihilism, science, and technology in order to outline an alternative account of embodiment and experience compatible with the natural sciences. The intention is to create a form of critical theory which it is argued not only is better equipped for addressing modes of power and exploitation in the present, but also for constructing alternate scenarios of the future. These twin issues are addressed on the one hand through an engagement with Mark Fisher’s and Simon Reynolds’ work on ‘90s rave culture and its mutation into present forms of postmodern cultural and psychosocial malaise, and on the other hand through recent accelerationist attempts to rethink the program of acceleration according to revisionary modernist and post-capitalist ends. It is argued that a cognitive reformatting grounded in the revision and remaking of the human on the basis of an updated model of digital psychedelia and a popular modernist aesthetic of cognitive mapping is crucial for overcoming the cognitive lacuna that Fredric Jameson characterizes in terms of a late capitalist discontinuity between structure and experience – and which the thesis suggests currently stifles the ambitions of critical theory on the one hand and cultural production on the other – and thereby realizes the transformative potentials of techno-scientific objectification by augmenting and transforming the parameters of the human.
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Bentley, Vanessa A. "Building a Feminist Philosophy of Cognitive Neuroscience." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447691278.
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