Dissertations / Theses on the topic 'Cognitive neuroscience'
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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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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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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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Blum, Bridget E. "Consumer Neuroscience: A Multi-disciplinary Approach to Marketing Leveraging Advances in Neuroscience, Psychology and Economics." Scholarship @ Claremont, 2016. http://scholarship.claremont.edu/cmc_theses/1414.
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For decades, neuroscience has greatly contributed to our foundational understanding of human behavior. More recently, the findings and methods of neuroscience have been applied to study the process of decision-making in order to offer advanced insights into the neural mechanisms that influence economic and consumer choices. In this thesis, I will address how customized marketing strategies can be enriched through the integration of consumer neuroscience, an integrative field anchored in the biological, cognitive and affective mechanisms of consumer behavior. By recognizing and utilizing these multidisciplinary interdependencies, marketers can enhance their advertising and promotional mix to elicit desired neural and affective consumer responses and measure these reactions in order to enhance purchasing decisions. The principal objective of this thesis is to present a comprehensive review of consumer neuroscience and to elucidate why it is an increasingly important area of study within the framework of human behavior. I will also describe how the insights gained from this emerging field can be leveraged to optimize marketing activities. Finally, I propose an experiment that illuminates key research questions, which may have considerable impact on the discipline of consumer neuroscience as well as the marketing industry.
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Norberg, Joakim. "Prediction of Future Development of MCI patients Based on Cognitive Function." Thesis, Stockholm University, Department of Psychology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6823.
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Mild Cognitive Impairment (MCI) refers to a transitional stage between normal aging and dementia. The purpose of this study was to predict the development of MCI patients based on cognitive function. 222 MCI patients were studied at baseline and at a follow-up of 2 years. Using discriminant analysis, they were predicted into four diagnostic groups: Improved, Stable MCI, Dementia of the Alzheimer’s Type (AD) and Other Dementia. Using four tests - Rey-Osterrieth Complex Figure Test recall, Auditory-Verbal Learning Test recall, TMTB time and Digit Symbol – overall 62.6% of cases were correctly classified after cross-validation. The rate of prediction in this study was 1.8 times better than chance, which is better than reported in most other studies. The model did best for the AD group with 80% of cases correctly classified. However, most cases in the Other Dementia group were also classified as AD.
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Ginley, Meredith K. "Neuroscience of Addiction." Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/etsu-works/8882.
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Kvaran, Trevor. "Dual-process theories and the rationality debate contributions from cognitive neuroscience /." unrestricted, 2007. http://etd.gsu.edu/theses/available/etd-08032007-161242/.
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Thesis (M.A.)--Georgia State University, 2007.Title from file title page. Andrea Scarantino, Eddy Nahmias, committee co-chairs; Erin McClure, committee member. Electronic text (68 p.) : digital, PDF file. Description based on contents viewed Jan. 7, 2008. Includes bibliographical references (p. 63-68).
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Chamorro, Emilia. "Theories of Nightmares in Cognitive Neuroscience and Psychology." Thesis, Högskolan i Skövde, Institutionen för biovetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-11496.
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Dreaming is a complex, multimodal and sequentially organized model of the waking world (Metzinger, 2003). Nightmares are a category of dreams involving threatening scenarios, anxiety and other negative emotions (Hartmann, 1998; Nielsen & Levin, 2007). Dreams and nightmares are explored in this present thesis in the light of psychology and modern cognitive neuroscience as to their nature, function and neural correlates. The three main dream theories and their leading investigations are reviewed to evaluate their evidence and overall explanatory power to account for the function of dreams and nightmares. Random Activation Theories (RATs) claim dreams are biological epiphenomena and by-products of sleep underlying mechanisms (Crick & Mitchison, 1983; Flanagan, 1995, 2000a, 2000b, Hobson & McCarley, 1997). Mood regulation theories consider that the psychological function of dreams is to regulate mood and help with the adaptation of individuals to their current environment such as solving daily concerns and recovery after trauma exposure (Hartmann, 1996; Levin, 1998; Stickgold, 2008; Kramer, 1991a, 1991b, 2014). Threat Simulation Theories of dreams present the evolutionary function for dreaming as a simulating off-line model of the world used to rehearse threatening events encountered in the human ancestral environment (Revonsuo, 2000a). With the threat-simulation system, threats were likely to be recognized and avoidance skills developed to guarantee reproductive success. TST consider nightmares to reflect the threat-simulation system fully activated (Revonsuo, 2000a). Supported by a robust body of evidence TST is concluded to be the most plausible theory at the moment to account as a theoretical explanation of dreams and nightmares
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Schroeter, Matthias. "Enlightening the brain : optical imaging in cognitive neuroscience /." Leipzig ; München : MPI for Human Cognitive and Brain Sciences, 2006. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=014995433&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Vasquez-Cropper, Marie E. "Engaging cognitive neurosciences in the classroom /." See Full Text at OhioLINK ETD Center (Requires Adobe Acrobat Reader for viewing), 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1103302896.
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Project requirement (M.Ed.)--University of Toledo, 2005.Typescript. "Submitted as partial fulfillment of the requirements of the Master of Education degree in Physical Education" Bibliography: leaves 43-46.
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Vasquez-Cropper, Marie E. "Engaging Cognitive Neurosciences in the Classroom." University of Toledo / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1103302896.
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Bailey, Phoebe Elizabeth Psychology Faculty of Science UNSW. "The social cognitive neuroscience of empathy in older adulthood." Awarded By:University of New South Wales. Psychology, 2009. http://handle.unsw.edu.au/1959.4/44506.
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Empathy is an essential prerequisite for the development and maintenance of close interpersonal relationships. Given that older adults are particularly vulnerable to the negative consequences of loneliness and social isolation, it is surprising that few studies have assessed empathy in this group. The current programme of research addressed this gap in the literature by testing competing predictions derived from Socioemotional Selectivity Theory and the Ageing-Brain Model for age-related sparing and impairment of empathy, respectively. Study 1 compared young (N = 80) and older (N = 49) adults?? self-reported levels of cognitive and affective empathy, and engagement in social activities. It was found that although affective empathy is spared, cognitive empathy is subject to age-related decline, and this decline mediates reductions in social participation. These data therefore affirmed the importance of further investigation into the nature, causes and potential consequences of age-related differences in empathy. Since disinhibition is one mechanism contributing to difficulty taking the perspective of another, and is known to increase with age, in Study 2, behavioural measures sensitive to inhibitory failure and to cognitive empathy were administered to young (N = 36) and older (N = 33) adults. One of the measures of cognitive empathy directly manipulated inhibitory demands, involving either high or low levels of self-perspective inhibition. The results indicated that older adults were selectively impaired on the high-inhibition condition, with cognitive disinhibition mediating this association. Study 2 therefore provided important evidence relating to one potential mechanism that contributes to age-related difficulties in perspective-taking. Studies 3 and 4 provided the first behavioural assessments of age-related differences in affective empathy by using electromyography to index facial expression mimicry. Study 3 found that young (N = 35) and older (N = 35) adults?? demonstrate comparable mimicry of anger, but older adults?? initial (i.e., implicit) reactions were associated with reduced anger recognition. Thus, to test the possibility that despite explicit recognition difficulties, implicit processing of facial expressions may be preserved in older adulthood, Study 4 compared young (N = 46) and older (N = 40) adults?? mimicry responses to subliminally presented angry and happy facial expressions. As predicted, the two groups demonstrated commensurate subconscious mimicry of these expressions. Taken together, these studies indicate that separate components of empathy are differentially affected by healthy adult ageing. Implications for competing perspectives of socioemotional functioning in older adulthood are discussed.
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Aktunc, Mahir Emrah. "Experimental Knowledge in Cognitive Neuroscience: Evidence, Errors, and Inference." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/28730.
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This is a work in the epistemology of functional neuroimaging (fNI) and it applies the error-statistical (ES) philosophy to inferential problems in fNI to formulate and address these problems. This gives us a clear, accurate, and more complete understanding of what we can learn from fNI and how we can learn it.
I review the works in the epistemology of fNI which I group into two categories; the first category consists of discussions of the theoretical significance of fNI findings and the second category discusses methodological difficulties of fNI. Both types of works have shortcomings; the first category has been too theory-centered in its approach and the second category has implicitly or explicitly adopted the assumption that methodological difficulties of fNI cannot be satisfactorily addressed. In this dissertation, I address these shortcomings and show how and what kind of experimental knowledge fNI can reliably produce which would be theoretically significant.
I take fMRI as a representative fNI procedure and discuss the history of its development. Two independent trajectories of research in physics and physiology eventually converge to give rise to fMRI. Thus, fMRI findings are laden in the theories of physics and physiology and I propose how this creates a kind of useful theory-ladenness which allows for the representation of and intervention in the constructs of cognitive neuroscience.
Duhemian challenges and problems of underdetermination are often raised to argue that fNI is of little, if any, epistemic value for psychology. I show how the ES notions of severe tests and error probabilities can be applied in epistemological analyses of fMRI. The result is that hemodynamic hypotheses can be severely tested in fMRI experiments and I demonstrate how these hypotheses are theoretically significant and fuel the growth of experimental knowledge in cognitive neuroscience.
Throughout this dissertation, I put the emphasis on the experimental knowledge we obtain from fNI and argue that this is the fruitful approach that enables us to see how fNI can contribute to psychology. In doing so, I offer an error-statistical epistemology of fNI, which hopefully will be a significant contribution to the philosophy of psychology.Ph. D.
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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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Barnes, Simon Dennis. "Psychopaths and insanity : law, ethics, cognitive neuroscience and criminal responsibility." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/psychopaths-and-insanity-law-ethics-cognitive-neuroscience-and-criminal-responsibility(a0121991-dfab-4d3b-a7fb-b4ec88a7f453).html.
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In many jurisdictions, including England and Wales, psychopaths are unable to succeed with an insanity defence. This has been influenced by a legal view of psychopathy as a condition characterised by a reduced ability to comply with the law, which is otherwise fully understood. Evidence from cognitive neuroscience, however, may potentially challenge this traditional legal conception of psychopathy. In this regard it has already been suggested, based partly on scientific evidence, that it may be appropriate for at least some psychopaths to succeed with an insanity defence where they can be shown to lack moral competence. In this thesis, I critically examine this possibility. I first examine the insanity defence in English law, showing how psychopaths have effectively been excluded from the defence by judicial interpretation of the insanity defence criteria. Consequently, if psychopaths lacking moral competence were to be identified, reform (or reinterpretation) of the defence would be required. I then present philosophical arguments in favour of the case that some psychopaths should gain access to an insanity defence, before clarifying which psychopaths ought potentially to succeed, and which criminal offences ought potentially to be relevant, for the purposes of a reformed or reinterpreted defence. In order to clarify which psychopaths are relevant psychopaths (RPs), it is necessary to go beyond existing scientific evidence. It is argued, based on emerging neuroscientific findings and current research techniques, that while it is not currently possible to identify RPs, it may be possible in the future. Even if it this becomes possible, however, the philosophical case for access to an insanity defence remains deeply problematic. Although RPs may lack moral competence, for example, they may nevertheless possess other capacities relevant to criminal responsibility. After closer examination, it is argued that the case for access to an insanity defence may be best viewed as a case for mitigation rather than exculpation. I conclude by considering some of the implications of this analysis in an English legal context, should it become possible to identify RPs. Of particular relevance is the possibility that RPs may be at high risk of causing serious harm to others. This illuminates important possible relationships between responsibility and risk, and diagnostic advancements and risk assessment, in this area. There are also broader implications for the management of psychopaths in the future, given that greater scientific understanding may lead to enhanced predictive abilities that could tempt policymakers towards more radical strategies. This thesis contributes to an ongoing debate about the role that cognitive neuroscience may play in decisions about the criminal responsibility of psychopaths. My main contribution is to clarify how psychopaths lacking moral competence may be identified in the future, and relate this neuroscientific discourse to arguments for providing these persons with access to an insanity defence. It is argued, however, by reference to legal, policy, scientific and philosophical considerations, that the risk such persons would pose, rather than their capacity for criminal responsibility per se, may have significant legal and policy implications in England and Wales in the future.
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Bellamy, Katarina Jane. "Cognitive neuroscience of false memory : the role of gist memory." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4471.
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This thesis explores the role of gist memory and gist representation in the formation of false recognition, specifically in the Deese, Roediger and McDermott Paradigm. We found that normal individuals displayed a range of susceptibility to false recognition and true recognition and this was related to their scores on both the Autism Spectrum Quotient and the Toronto-Alexithymia Scale. More ‘male-brained’ participants exhibited less susceptibility to false recognition but also less veridical recognition. The reverse was true for more ‘female-brained’ participants. The idea of false recognition and gist memory lying along a continuum was further emphasised by work on individuals with Autism Spectrum Disorder. We found they were less susceptible to false recognition but also produced less veridical recognition. We also found differences in performance between two groups of autism individuals who also differed in age. The results of further manipulations using both picture and word paradigms suggested that gist memory could be improved in younger individuals with autism. We also examined a patient group with Functional Memory Disorder using the DRM paradigm and a confabulation task and found them less able to produce true recognition in the DRM compared with a control group. Their memory impairments could not be attributed to depression since none were clinically depressed, so we suggested that they represent the tale end of impairment to gist memory. We also explored gist memory in a patient with dense anterograde amnesia who showed reduced true recognition and a tendency to reduced false recognition, but through manipulation of the stimuli using word and pictorial material she could perform like controls due to improved item-specific discrimination. A new face recognition paradigm was also tested in which she showed a tendency towards increased false recognition in comparison with controls. Finally, we suggest the use of the DRM paradigm as a test for memory malingering since we found participants could not replicate the performance of amnesia patients without a cost in their response latencies. This is discussed through the case study of GC a man suspected of exaggerating his memory symptoms.
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Mohamed, Ahmed Dahir. "The neuroscience & ethics of cognitive enhancement in healthy individuals." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607755.
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Heikura, Emelie. "Resilience in cognitive neuroscience : The 'Ordinary Magic' of human recovery." Thesis, Högskolan i Skövde, Institutionen för biovetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-15568.
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Resilience is a dynamic process that reflect individual ability to successfully recover and positively adapt to severe circumstances. In this essay, attachment, social support, self- regulation and affective processing, taken from the "shortlist of resilience" provided by Masten, are further analyzed and connected to findings within neuroscience. The result suggest that brain areas originated from the prefrontal cortex, such as orbitofrontal and dorsolateral cortex, are two major neural correlates to attachment and stress- and self- regulation. The amygdala is also an area of interest, because of its’ connection to emotions and affective memories. Research on affective style suggest that the functions associated with the prefrontal cortex are dampening the effect of the amygdala, which later supports resilience and recovery. The area of resilience is suffering from a lacking general definition, measurement and operationalization, which is argued to be the major challenge of this research area. Prominent researchers prospect that resilience research will continue to flourish within the area of neuroscience, and that further discoveries will be made concerning how this cognitive ability is related to structural and functional differences in the brain.
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Cronin, Beau D. "Quantifying uncertainty in computational neuroscience with Bayesian statistical inference." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45336.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Brain and Cognitive Sciences, 2008.Includes bibliographical references (p. 101-106).
Two key fields of computational neuroscience involve, respectively, the analysis of experimental recordings to understand the functional properties of neurons, and modeling how neurons and networks process sensory information in order to represent the environment. In both of these endeavors, it is crucial to understand and quantify uncertainty - when describing how the brain itself draws conclusions about the physical world, and when the experimenter interprets neuronal data. Bayesian modeling and inference methods provide many advantages for doing so. Three projects are presented that illustrate the advantages of the Bayesian approach. In the first, Markov chain Monte Carlo (MCMC) sampling methods were used to answer a range of scientific questions that arise in the analysis of physiological data from tuning curve experiments; in addition, a software toolbox is described that makes these methods widely accessible. In the second project, the model developed in the first project was extended to describe the detailed dynamics of orientation tuning in neurons in cat primary visual cortex. Using more sophisticated sampling-based inference methods, this model was applied to answer specific scientific questions about the tuning properties of a recorded population. The final project uses a Bayesian model to provide a normative explanation of sensory adaptation phenomena. The model was able to explain a range of detailed physiological adaptation phenomena.
by Beau D. Cronin.
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Martin, Jonathan. "Finding Useful Concepts of Representation in Cognitive Neuroscience: A new tactic for addressing dynamical critiques of representational models of cognition, action, and perception." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1571833717613181.
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Skerry, Amy Elizabeth. "Abstract Representations of Attributed Emotion: Evidence From Neuroscience and Development." Thesis, Harvard University, 2015. http://nrs.harvard.edu/urn-3:HUL.InstRepos:17467378.
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Humans can recognize others’ emotions based on overt cues such as facial expressions, affective vocalizations, or body posture, or by recruiting an abstract, causal theory of the conditions that tend to elicit different emotions. Whereas previous research has investigated the recognition of emotion in specific perceptual modalities (e.g. facial expressions), this dissertation focuses on the abstract representations that relate observable reactions to their antecedent causes. A combination of neuroimaging, behavioral, and developmental methods are used to shed light on the mechanisms that support various forms of emotion attribution, and to elucidate the core features or dimensions that structure the space of emotions we represent.
Chapter 1 identifies brain regions that contain information about emotional valence conveyed either via facial expressions and or via animations depicting abstract situational information. These data reveal regions with modality-specific representations of emotional valence (i.e. patterns of activity that discriminate only positive versus negative facial expressions), as well as modality-independent representations: in medial prefrontal cortex (MPFC), the valence representation generalizes across stimuli, indicating a common neural code that abstracts away from specific perceptual features and is invariant to different forms of evidence. Building on evidence that young infants discriminate and respond to the emotional expressions of others, Chapter 2 investigates whether infants also represent these expressions in relation to the situations that elicit them. The results of several experiments demonstrate that infants within their first year of life have expectations about how facial and vocal displays of emotion relate to the valence of events that precede them. Whereas Chapters 1 and 2 focus on a simple binary distinction between positive and negative affect, Chapter 3 investigates a space of more fine-grained discriminations (e.g. someone feeling proud vs. grateful). A combination of multi- voxel pattern analyses and representational similarity analyses reveal brain regions containing abstract and high-dimensional representations of attributed emotion. Moreover, a set of causal features (encoding properties of eliciting events that vary between different emotions) outperforms more primitive dimensions in capturing neural similarities within these regions. Together, these studies provide a newly detailed characterization of the representations that structure emotion attribution, including their development and neural basis.Psychology
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Kvaran, Trevor Hannesson. "Dual-Process Theories and the Rationality Debate: Contributions from Cognitive Neuroscience." Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/philosophy_theses/20.
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The past 40 years have seen an enormous amount of research aimed at investigating human reasoning and decision-making abilities. This research has led to an extended debate about the extent to which humans meet the standards of normative theories of rationality. Recently, it has been proposed that dual-process theories, which posit that there are two distinct types of cognitive systems, offer a way to resolve this debate over human rationality. I will propose that the two systems of dual-process theories are best understood as investigative kinds. I will then examine recent empirical research from the cognitive neuroscience of decision-making that lends empirical support to the theoretical claims of dual-process theorists. I will lastly argue that dual-process theories not only offer an explanation for much of the conflicting data seen in decision-making and reasoning research, but that they ultimately offer reason to be optimistic about the prospects of human rationality.
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Laycock, Suzanna K. "The Cognitive Neuroscience of Developmental Dyslexia : the Role of the Cerebellum." Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522553.
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Longworth, Catherine Elaine. "Understanding the regular past tense in English : a cognitive neuroscience approach." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619663.
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Björklund, Patrik, and Anna Rydin. "Automation Pipelines for Efficient and Robust Experimental Research Within Cognitive Neuroscience." Thesis, Uppsala universitet, Avdelningen för visuell information och interaktion, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-453741.
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The current trend towards large-scale research projects with big quantities of data from multiple sources require robust and efficient data handling. This thesis explores techniques for automatizing research data pipelines. Specifically, two tasks related to automation within a long-term research project in cognitive neuroscience are addressed. The first task is to develop a tool for automatic transcribing of paper-based questionnaires using computer vision. Questionnaires containing continuous scales, so called visual analog scales (VASs), are used extensively in e.g. psychology. Despite this, there currently exists no tool for automatic decoding of these types of questionnaires. The resulting computer vision system for automatic questionnaire transcribing we present, called "VASReader", reliably detects VAS marks with an accuracy of 98%, and predicts their position with a mean absolute error of 0.3 mm when compared to manual measurements. The second task addressed in this thesis project is to investigate whether machine learning can be used to detect anomalies in Magnetic Resonance Imaging (MRI) data. An implementation of the unsupervised anomaly detection technique Isolation Forest shows promising results for the detection of anomalous data points. The model is trained on image quality metric (IQM) data extracted from MRI. However, it is concluded that the site of scanning and MRI machine model used affect the IQMs, and that the model is more prone to classify data points originating from machines and institutions that have less support in the database as anomalous. An important conclusion from both tasks is that automation is possible and can be a great asset to researchers, if an appropriate level and type of automation is selected.
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Vellmer, Sebastian. "Applications of the Fokker-Planck Equation in Computational and Cognitive Neuroscience." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21597.
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In dieser Arbeit werden mithilfe der Fokker-Planck-Gleichung die Statistiken, vor allem die Leistungsspektren, von Punktprozessen berechnet, die von mehrdimensionalen Integratorneuronen [Engl. integrate-and-fire (IF) neuron],
Netzwerken von IF Neuronen und Entscheidungsfindungsmodellen erzeugt werden.
Im Gehirn werden Informationen durch Pulszüge von Aktionspotentialen kodiert.
IF Neurone mit radikal vereinfachter Erzeugung von Aktionspotentialen haben sich in Studien die auf Pulszeiten fokussiert sind als Standardmodelle etabliert. Eindimensionale IF Modelle können jedoch beobachtetes Pulsverhalten oft nicht beschreiben und müssen dazu erweitert werden. Im erste Teil dieser Arbeit wird eine Theorie zur Berechnung der Pulszugleistungsspektren von stochastischen, multidimensionalen IF Neuronen entwickelt. Ausgehend von der zugehörigen Fokker-Planck-Gleichung werden partiellen Differentialgleichung abgeleitet, deren Lösung sowohl die stationäre Wahrscheinlichkeitsverteilung und Feuerrate, als auch das Pulszugleistungsspektrum beschreibt.
Im zweiten Teil wird eine Theorie für große, spärlich verbundene und homogene Netzwerke aus IF Neuronen entwickelt, in der berücksichtigt wird, dass die zeitlichen Korrelationen von Pulszügen selbstkonsistent sind. Neuronale Eingangströme werden durch farbiges Gaußsches Rauschen modelliert, das von einem mehrdimensionalen Ornstein-Uhlenbeck Prozess (OUP) erzeugt wird. Die Koeffizienten des OUP sind vorerst unbekannt und sind als Lösung der Theorie definiert. Um heterogene Netzwerke zu untersuchen, wird eine iterative Methode erweitert.
Im dritten Teil wird die Fokker-Planck-Gleichung auf Binärentscheidungen von Diffusionsentscheidungsmodellen [Engl. diffusion-decision models (DDM)] angewendet. Explizite Gleichungen für die Entscheidungszugstatistiken werden für den einfachsten und analytisch lösbaren Fall von der Fokker-Planck-Gleichung hergeleitet. Für nichtliniear Modelle wird die Schwellwertintegrationsmethode erweitert.This thesis is concerned with the calculation of statistics, in particular the power spectra, of point processes generated by stochastic multidimensional integrate-and-fire (IF) neurons, networks of IF neurons and decision-making models from the corresponding Fokker-Planck equations. In the brain, information is encoded by sequences of action potentials. In studies that focus on spike timing, IF neurons that drastically simplify the spike generation have become the standard model. One-dimensional IF neurons do not suffice to accurately model neural dynamics, however, the extension towards multiple dimensions yields realistic behavior at the price of growing complexity. The first part of this work develops a theory of spike-train power spectra for stochastic, multidimensional IF neurons. From the Fokker-Planck equation, a set of partial differential equations is derived that describes the stationary probability density, the firing rate and the spike-train power spectrum. In the second part of this work, a mean-field theory of large and sparsely connected homogeneous networks of spiking neurons is developed that takes into account the self-consistent temporal correlations of spike trains. Neural input is approximated by colored Gaussian noise generated by a multidimensional Ornstein-Uhlenbeck process of which the coefficients are initially unknown but determined by the self-consistency condition and define the solution of the theory. To explore heterogeneous networks, an iterative scheme is extended to determine the distribution of spectra. In the third part, the Fokker-Planck equation is applied to calculate the statistics of sequences of binary decisions from diffusion-decision models (DDM). For the analytically tractable DDM, the statistics are calculated from the corresponding Fokker-Planck equation. To determine the statistics for nonlinear models, the threshold-integration method is generalized.
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Slimak, Louis Jason. "A MIND WITH A VIEW: COGNITIVE SCIENCE, NEUROSCIENCE AND CONTEMPORARY LITERATURE." Akron, OH : University of Akron, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=akron1176747219.
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Thesis (M.A.)--University of Akron, Dept. of English, 2007."May, 2007." Title from electronic thesis title page (viewed 4/26/2009) Advisor, Sheryl Stevenson; Faculty Reader, Bob Pope; Department Chair, Diana Reep; Dean of the College, Ronald F. Levant; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.
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Sheridan, Alexandra. "Monotony and Deprivation: The Effects of Long-Term Imprisonment on the Neurocognitive Functioning of the Older Prison Inmate Population." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/scripps_theses/337.
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Risk factors of the prison environment have been considered from a policy perspective, however little work in the field of neuroscience and neuropsychology has been done to further understand the effects that long-term incarceration have on the brain at a neuronal and cognitive level. Neurocognitive deficits in the older prison inmate population usually go undetected, thus there is a need for the precise characterization of neurocognitive impairment, its course and etiology specifically in the prison population. This study will combine cross sectional and longitudinal analysis to characterize the neurocognitive impairment in the older prison inmate population versus the non-incarcerated population while paying close attention to the effects of poor nutrition, lack of preventative healthcare, and social isolation on the neurocognitive functioning of the older inmate population. Based on previous work, it is hypothesized that lack of preventative healthcare in the prison system results in improper treatment of such health conditions as diabetes and vascular disease, each of which have been shown to increase the chances of dementia diagnosis. In addition, it is hypothesized that prison diets low in polyunsaturated fatty acids and vitamin B12 and high in saturated fats impair the functioning of brain regions involved in memory consolidation, retrieval and executive functioning, like the hippocampus and the frontal lobe. Furthermore, due to inadequate environmental stimulation, increased levels of anxiety, and unsatisfactory interactions with peers, it is hypothesized that social isolation decreases neurocognitive functioning in the older prison inmate population at a faster rate compared to the non-institutionalized population. Over the course of seven years, I propose that prisoners be administered the Montreal Cognitive Assessment (MoCA) to measure neurocognitive impairment as well as the State-Trait Anxiety Inventory (STAI) to measure levels of anxiety and proneness to anxious feelings. In addition, a phlebotomist will draw a sample of blood from each participant in order to measure their levels of saturated fat, polyunsaturated fatty acids, and vitamin B12. In a longitudinal analysis, 400 prisoners will be monitored every other year for seven years. In the cross sectional analysis, 200 prisoners will be matched to 200 non-incarcerated individuals based on age, background and health status in order to determine the effects that poor health and environmental factors have on the neurocognitive functioning of the older inmate population versus the non-incarcerated population. Results from the longitudinal analysis and the cross sectional analysis will be analyzed using repeated measures ANOVA and regression analysis respectively.
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Tschentscher, Nadja. "How things are adding up : the neural dynamics of arithmetic problem solving as revealed by fMRI and EEG-MEG." Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648523.
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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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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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Thompson, Todd Wesley. "Cognitive neuroscience of training and transfer in working memory and visual attention." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/97787.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Brain and Cognitive Sciences, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 133-142).
The trained enhancement of working memory and visual attention has both theoretical implications for understanding the architectures of cognition, as well as practical implications for education and clinical treatment. In particular, transfer of training from one task to another may reveal shared psychological processes or neural systems across domains of cognition. In three experiments presented here, participants underwent a month of intensive training on either a complex working memory task or a visual attention task. Although participants made substantial gains on the trained tasks, that training did not yield transfer to untrained tasks measuring fluid intelligence, reading comprehension, or processing speed (Experiment 1). Brain imaging conducted before and after training revealed that increased working memory performance was accompanied by decreases of functional activation within anatomically circumscribed regions of frontal and parietal cortex as well as more wide-spread increases in frontoparietal functional connectivity (Experiment 2). Visual attention training using adaptively adjusted speeds on a multiple object tracking task revealed sizeable gains on the task itself, and those gains enabled the tracking of an increased number of items at a constant speed. This transfer from speed to quantity suggests that a common process underlies tracking speed and tracking capacity in visual attention (Experiment 3).
by Todd Wesley Thompson.
Ph. D.
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Mair, Carolyn. "Toward a further understanding of object feature binding : a cognitive neuroscience perspective." Thesis, Bournemouth University, 2006. http://eprints.bournemouth.ac.uk/10536/.
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The aim of this thesis is to lead to a further understanding of the neural mechanisms underlying object feature binding in the human brain. The focus is on information processing and integration in the visual system and visual shortterm memory. From a review of the literature it is clear that there are three major competing binding theories, however, none of these individually solves the binding problem satisfactorily. Thus the aim of this research is to conduct behavioural experimentation into object feature binding, paying particular attention to visual short-term memory. The behavioural experiment was designed and conducted using a within-subjects delayed responset ask comprising a battery of sixty-four composite objects each with three features and four dimensions in each of three conditions (spatial, temporal and spatio-temporal).Findings from the experiment,which focus on spatial and temporal aspects of object feature binding and feature proximity on binding errors, support the spatial theories on object feature binding, in addition we propose that temporal theories and convergence, through hierarchical feature analysis, are also involved. Because spatial properties have a dedicated processing neural stream, and temporal properties rely on limited capacity memory systems, memories for sequential information would likely be more difficult to accuratelyr ecall. Our study supports other studies which suggest that both spatial and temporal coherence to differing degrees,may be involved in object feature binding. Traditionally, these theories have purported to provide individual solutions, but this thesis proposes a novel unified theory of object feature binding in which hierarchical feature analysis, spatial attention and temporal synchrony each plays a role. It is further proposed that binding takes place in visual short-term memory through concerted and integrated information processing in distributed cortical areas. A cognitive model detailing this integrated proposal is given. Next, the cognitive model is used to inform the design and suggested implementation of a computational model which would be able to test the theory put forward in this thesis. In order to verify the model, future work is needed to implement the computational model.Thus it is argued that this doctoral thesis provides valuable experimental evidence concerning spatio-temporal aspects of the binding problem and as such is an additional building block in the quest for a solution to the object feature binding problem.
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Assi, Abed Al-Nasser Hafes. "Structural magnetic resonance image analyses of the brain : applications in cognitive neuroscience." Thesis, University of Liverpool, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439468.
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Spanò, Goffredina, and Goffredina Spanò. "Rethinking Memory in Typical and Atypical Development: New Perspectives from Cognitive Neuroscience." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/621439.
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Recent research provides evidence for new conceptualizations of memory, including the brain's drive to predict and anticipate future events based on past experiences, a narrowing gap between perceptual and mnemonic functions, and the importance of sleep-dependent memory consolidation. These new perspectives, which highlight the interactive nature of the brain bases of memory, are rarely applied to the study of memory in neurodevelopmental disorders. In the present work, I adopted some of these theoretical perspectives to rethink the study of memory in typical development and in neurodevelopmental disorders such as Down syndrome (Trisomy 21). Given that several studies have reported atypical patterns of brain connectivity in individuals with Down syndrome, this dissertation aims to assess the integrity of memory processing in this population by examining different levels of cross-regional communication measured at the neuropsychological level. I first provide evidence of impaired rapid interactions between the brain areas that mediate high-level influences on figure-ground perception and relatively unimpaired integration of neural inputs across local areas of visual cortex (Spanò, Peterson, Nadel, Rhoads, & Edgin, 2015; see Appendix A). In the second study, I demonstrate spared use of anticipatory scene representation, thought to rely on top-down information from the hippocampus and likely to support our understanding of the properties of the visual world (Spanò, Intraub, & Edgin, submitted; see Appendix B). Finally, the third study reveals impaired sleep-dependent memory consolidation of arbitrary object-label associations, symptomatic of a weak dialogue between prefrontal cortex and hippocampus (Spanò, Gómez, Demara, Alt, Cowen, & Edgin, in preparation; see Appendix C). Based on these findings, treatments for Down syndrome, and other developmental disorders affecting functional connectivity, should be aimed at establishing balanced neural communication and cross-regional connectivity early on in development.
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Arsenault-Lapierre, Geneviève. "A longitudinal study of cortisol secretion in mild cognitive impairment." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107579.
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Individuals with Mild Cognitive Impairment (MCI) are at an increased risk of progressing to Alzheimer's disease (AD). However, not all individuals progress, and research on biomarkers is needed. One area of research has focused on the hippocampus as it is one of the first regions affected in AD, in addition to being an important modulator of the Hypothalamic-Pituitary-Adrenal axis, involved in the secretion of cortisol. We now know that AD patients are hypersecretors of cortisol compared to normal elderly (NE). Therefore, the general goals of this dissertation were to examine the secretion of cortisol in MCI individuals compared to NE and AD patients, both in cross-section and longitudinally. In the first study, we demonstrated that MCI individuals, as well as AD patients, secrete higher cortisol than NE when we control for the season of sampling. In a second study, we found that cortisol measured at baseline significantly contributes to a logistic regression model of progression to AD in MCI individuals. We also noted that the direction of the association between cortisol levels and future disease progression in MCI individuals, although marginally independent, is negative. Lower cortisol levels are thus associated with higher risk of progression. Additionally, we found that individuals with MCI who progress to AD were the only ones to show a statistically significant increase in cortisol secretion over the years. MCI participants who remained cognitively stable, NE, and AD patients all secreted steady cortisol levels over time. In a third study, we explored a psychosocial explanation for the cortisol increase over time observed in MCI who progressed to AD. However, anosognosia for dementia was significantly associated with anosognosia for perceived stress in these individuals, preventing us from deriving further conclusions. In this same study, we found that anosognosia for dementia does not correlate with cortisol levels, therefore ruling out the possibility that anosognosia may have explained the negative association between cortisol and future risk of progression to AD in MCI individuals (see second study). Finally, in a fourth study, we examined a neuropathological explanation for the cortisol increases over time found in the MCI group who progressed to AD. Cortisol levels did not correlate with amyloid-beta deposition, as measured with PiB-PET imaging, nor did they correlate with visual rating of medial temporal atrophyIn this dissertation, we investigated the patterns of cortisol secretion in MCI individuals with the overall objective of improving clinical prognostication. Our results suggest that there is a link between cortisol levels and MCI and AD. However, this relationship is probably indirect in nature, complex, and time-dependent (the direction varies with the progression of the disease). Although the utility of cortisol measurement as a biomarker for progression to AD in individuals with MCI remains to be further examined, understanding the association between cortisol and AD may provide some insights in the progression of the disease.Les gens atteints de Troubles Cognitifs Légers (TCL) sont à risque de développer la Maladie d'Alzheimer (MA). Mais tous ne progressent pas. Des études sont en cours afin d'identifier des bio marqueurs qui aideraient au pronostic. Un champ de recherche prend avantage du fait que l'hippocampe, première partie du cerveau atteinte dans la MA, soit aussi un important modulateur de l'axe Hypothalamo-Hypophyso-Surrénalien, responsable de la sécrétion de cortisol. Il est notoire, par ailleurs, que les patients atteints de MA sont des hyper sécréteurs de cortisol. Les buts généraux de cette dissertation étaient donc d'examiner, de façon transversale et longitudinale, la sécrétion de cortisol chez les gens atteints de TCL et de la comparer à celle des personnes âgées en santé et des patients atteints de la MA. Dans une première étude, nous avons démontré que lorsque l'on contrôle pour les variations saisonnières, les gens atteints de TCL, tout comme les patients atteints de MA, sécrètent des niveaux plus élevés que les personnes âgées en santé. Dans une deuxième étude, nous avons démontré que les mesures de cortisol à « baseline » contribuent significativement à un modèle de régression logistique sur le risque de progression vers la MA chez les gens atteints de TCL. Cependant, la direction de l'association, bien que statistiquement marginale, était négative, c'est-à-dire que les niveaux de cortisol bas à « baseline » sont associés à un risque plus élevé de progression. De plus, nous avons démontré que seuls les gens atteints de TCL qui progressent vers la MA montrent des augmentations significatives de cortisol au cours des deux années de suivi. Les gens atteints de TCL qui ne progressent pas, les contrôles âgés, et les patients atteints de MA montrent des niveaux de cortisol stables. Dans une troisième étude, nous avons exploré les effets psychosociaux pouvant expliquer une augmentation des niveaux de cortisol chez les gens atteints de TCL qui progressent vers la MA. Cependant, nous avons trouvé que l'anosognosie pour la démence a un impact significatif sur les niveaux de stress perçu chez ces individus, nous empêchant donc de conclure définitivement sur ce point. Dans cette même étude, par contre, nous avons trouvé que l'anosognosie ne corrèle pas avec les niveaux de cortisol. Ce qui nous permet de penser que l'association entre les niveaux bas de cortisol et un risque élevé de progression vers la MA (voire deuxième étude) ne serait pas due à l'anosognosie des gens atteints de TCL. Finalement, dans une quatrième étude, nous avons examiné les effets de la propagation neuropathologique de la MA sur l'augmentation significative de cortisol chez les gens atteints de TCL qui progressent vers la MA. Nous avons trouvé que les niveaux de cortisol ne corrèlent pas avec la déposition de plaques amyloid, imagées par TEP grâce au radioligand PiB. De plus, les niveaux de cortisol ne corrèlent pas avec une mesure visuelle de l'atrophie du lobe medio temporal. Dans cette dissertation, nous avons examiné les patrons de sécrétion de cortisol de façon transversale et longitudinale, dans le but éventuellement d'utiliser les mesures de cortisol dans le pronostic des gens atteints de TCL. Bien qu'un lien entre le cortisol et la MA soit probable, cette relation semble indirecte, complexe, et tributaire du temps (la direction de l'association varie au cours de la progression de la maladie). Il en demeure que les résultats présentés dans cette dissertation contribuent à l'amélioration des connaissances quant aux mécanismes sous-jacents à la maladie d'Alzheimer.
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Wright, Sean Patrick. "Cognitive neuroscience of episodic memory: behavioral, genetic, electrophysiological, and computational approaches to sequence memory." Thesis, Boston University, 2003. https://hdl.handle.net/2144/27805.
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Boston University. University Professors Program Senior theses.PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
2031-01-02
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Pinheiro, Chagas Munhos De Sa Moreira Pedro. "Characterizing the neurocognitive mechanisms of arithmetic." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066542/document.
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L'arithmétique est une des inventions majeures de l'humanité, mais il nous manque encore une compréhension globale de la façon dont le cerveau calcule les additions et soustractions. J'ai utilisé une nouvelle méthode comportementale basée sur un suivi de trajectoire capable de disséquer la succession des étapes de traitement impliquées dans les calculs arithmétiques. Les résultats sont compatibles avec un modèle de déplacement pas à pas sur une ligne numérique mentale, en commençant par l'opérande le plus grand et en ajoutant ou soustrayant de manière incrémentielle l'opérande le plus petit. Ensuite, j'ai analysé les signaux électrophysiologiques enregistrés à partir du cortex humain pendant que les sujets résolvaient des additions. L'activité globale dans le sillon intrapariétal augmentait au fur et à mesure que les opérandes grossissaient, prouvant son implication dans le calcul et la prise de décision. Étonnamment, les sites dans le gyrus temporal inférieur postérieur ont montré que l’activation initiale diminuait en fonction de la taille du problème, suggérant un engagement dans l'identification précoce de la difficulté de calcul. Enfin, j'ai enregistré des signaux de magnétoencéphalographie pendant que les sujets vérifiaient les additions et soustractions. En appliquant des techniques d'apprentissage automatique, j'ai étudié l'évolution temporelle des codes de représentation des opérandes et fourni une première image complète d'une cascade d'étapes de traitement en cours sous-jacentes au calcul arithmétique. Ainsi, cette dissertation fournit-elle plusieurs contributions sur la façon dont les concepts mathématiques élémentaires sont mis en œuvre dans le cerveauArithmetic is one of the most important cultural inventions of humanity, however we still lack a comprehensive understanding of how the brain computes additions and subtractions. In the first study, I used a novel behavioral method based on trajectory tracking capable of dissecting the succession of processing stages involved in arithmetic computations. Results supported a model whereby single-digit arithmetic is computed by a stepwise displacement on a spatially organized mental number line, starting with the larger operand and incrementally adding or subtracting the smaller operand. In a second study, I analyzed electrophysiological signals recorded from the human cortex while subjects solved addition problems. I found that the overall activity in the intraparietal sulcus increased as the operands got larger, providing evidence for its involvement in arithmetic computation and decision-making. Surprisingly, sites within the posterior inferior temporal gyrus showed an initial burst of activity that decreased as a function of problem-size, suggesting an engagement in the early identification of the calculation difficulty. Lastly, I recorded magnetoencephalography signals while subjects verified additions and subtractions. By applying machine learning techniques, I investigated the temporal evolution of the representational codes of the operands and provided a first comprehensive picture of a cascade of unfolding processing stages underlying arithmetic calculation. Overall, this dissertation provides several contributions to our knowledge about how elementary mathematical concepts are implemented in the brain
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Biotti, Federica. "Understanding the cognitive mechanisms of developmental prosopagnosia." Thesis, City, University of London, 2018. http://openaccess.city.ac.uk/21802/.
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Developmental prosopagnosia (DP) is a condition associated with severe difficulties recognising familiar faces, which occurs in individuals with normal intelligence, typical low-level vision, and in the absence of manifest brain injuries. The neuro-cognitive origins of DP are still debated. Cognitive accounts have attributed face recognition deficits to reduced holistic processing of faces (i.e., whereby individual features of faces are integrated into a unified perceptual whole), and mnemonic difficulties, whereby prosopagnosics may be able to form accurate percepts, but are unable to maintain those percepts over time. At the neurological level, differences have been reported in the structural and functional connectivity of occipito-temporal regions which include face selective areas. Chapter 2 of this thesis investigated facial emotion recognition in DP and revealed widespread difficulties recognising facial emotion in individuals with apperceptive profiles of DP (i.e., DPs exhibiting difficulties forming view-invariant structural descriptions of faces at early stages of encoding). Chapter 3 explored body recognition in DP and found evidence of impaired body and object recognition in DP individuals. Moreover, the lack of relationship between observers' object and body recognition performances suggested that body and object recognition impairments in DP may co-occur independently. Chapter 4 investigated the susceptibility to the composite face illusion in two independent samples of individuals with DP and failed to show evidence of diminished composite face effects in both samples. Finally, Chapter 5 considered the contribution of perceptual encoding and short term face memory in DP using a delayed match-to-sample task and found that recognition impairments in prosopagnosics were insensitive to changes in retention interval and viewing angle, supporting an apperceptive characterisation of DP. The implications of these findings for the characterisation of DP and for understanding its underlying cognitive mechanisms, are discussed in Chapter 6.
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Wittmann, Marco. "From actions to agents : value representation in frontal cortex." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:37387351-cd95-4f24-ad16-1cc67d181a7b.
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In this thesis, I investigated computational and neural mechanisms underlying foraging-related behavior in humans. A consideration of the ecological constraints under which mammalian behavior first evolved guided my investigation of learning and decision-making in frontal cortex. When engaged in foraging, animals have to figure out how profitable their actions are and whether it is better to continue foraging in their current environment or to switch to an alternative. They have to track the reward income of their actions over time and also take into account that the actions of other foraging animals have a direct influence on their reward income (Chapter 1). Based on these observations, I looked at similar types of behavior in humans using computational modeling and functional magnetic resonance imaging. I studied how people evaluate the profitability of their actions over time (Chapter 2). Dorsal anterior cingulate cortex carried a detailed representation of the value of the current foraging action, which was influenced by reward memories with different time constants (Chapter 3). Tracking the reward income of one's actions is not only important in order to learn about the profitability of the environment, it can also inform estimates of one's own and other people's abilities. Ability estimates can be used in a direct way to predict the reward outcome that the actions of one's own self and others will have. I found that people learn about their own and others' abilities in a rational manner but also that ability estimates of self and other were partly confused with each other, depending on whether subjects cooperated or competed with each other (Chapter 4). The confusion effect is reflected in Brodmann area 9 activity indicating that area 9 integrates self and other related information. Perigenual anterior cingulate tracked the ability estimates for oneself, suggesting that it might compute the success expectation of an action independent of particular features of the environment (Chapter 5). In sum, different subregions of medial frontal cortex carried different types of action-related value representations that can guide decision-making.
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Krause, Margaret Billings. "Facilitating a Transdisciplinary Approach in Teacher Education Through Multimodal Literacy and Cognitive Neuroscience." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5718.
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This dissertation is a compilation of research and theoretical papers based on the affordances of multimodal literacies for marginalized learners and for pre-service teachers’ developing conceptualizations of literacy. Through a transdisciplinary lens, the author considers complex issues presented in traditional, print-based learning environments that potentially marginalize learners in their developing abilities to become successful participants in the multiple literacies in the real world.
Three studies focus on pre-service teachers and their developing understanding of effective literacy-related classroom practices. Chapter Three explores potential affordances of a multimodal learning environment for pre-service teachers with self-identified reading difficulties. The phenomenological study highlights differing needs of pre-service teachers with reading difficulties as they navigate the meaning-making process within a literacy methods course. Further, it provides tangible examples of the interplay between neurocognitive mechanisms and the social and cultural factors students face as they work within a variety of modal platforms. Through a qualitative case study, Chapters Eight and Nine explore the ways multimodal learning experiences within a literacy methods course influenced pre-service teachers’ literacy identities and how their developing identities translated into classroom pedagogical decisions. Chapter Nine proposes a framework for understanding pre-service teachers’ developing literacy identities.
Chapters Five and Six explore the needs of learners marginalized in traditional, print- based classrooms through a critical and theoretical lens. Chapter Five explores the authentic literacy practices of the author’s son, who is identified as a talented learner, yet unmotivated in the traditional classroom setting. She argues traditional conceptualizations of literacy as reliant on print forms of text are outdated and unresponsive to the dynamic changes of the 21st century. Further, the author argues the lack of responsiveness to dynamic and multimodal characteristics of the globalized world contribute to the perceived lack of motivation talented boys demonstrate in school-based literacy spaces. Chapter Six provides a review the literature on the “functional circuitry of the reading brain” (Schlaggar & McCandliss, 2007), and it reviews neuroscientific studies of individuals with developmental dyslexia (Lyon, Shaywitz, & Shaywitz, 2003), which provide evidence for amodal sluggish attentional shifting (SAS) as a causal factor for amodal temporal processing deficits.
The author provides autoethnographic vignettes between research and theoretical papers, serving as insight into the author’s journey in her own literacy identity development. While chapters following each vignette utilize a variety of qualitative methodologies and review empirical research, the author’s goal is to take the reader on a journey as she weaves together her work as a literacy researcher and educator. Ultimately, the author’s intention is to evoke both emotion and greater understanding about what it means to be literate in our dynamic society.
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Vellmer, Sebastian [Verfasser]. "Applications of the Fokker-Planck Equation in Computational and Cognitive Neuroscience / Sebastian Vellmer." Berlin : Humboldt-Universität zu Berlin, 2020. http://d-nb.info/1214240682/34.
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CROCE, Enrico. "TEMPORALITY and INTERSUBJECTIVITY IN SCHIZOPHRENIA, A DIALOGUE BETWEEN PSYCHOPATHOLOGICAL PHENOMENOLOGY AND COGNITIVE NEUROSCIENCE." Doctoral thesis, Università degli studi di Ferrara, 2021. http://hdl.handle.net/11392/2488114.
Full textAbstract:
La psichiatria, da sempre disciplina di confine, porta in sé anime diverse. Storicamente, alcuni dei principali contributi, in particolare per quanto riguarda la schizofrenia, sono venuti dalla psicopatologia fenomenologica. Questa disciplina, con la sua profonda attenzione alle strutture
dell'esperienza, è guardata con crescente attenzione al fine di limitare l'appiattimento nosografico degli attuali sistemi diagnostici. D'altra parte, lo sviluppo delle neuroscienze cognitive rende ormai indispensabile, per una disciplina che vuole mantenere i propri confini all'interno delle scienze mediche, sottoporsi alla validazione empirica dei costrutti neurobiologici. Ho focalizzato il mio lavoro di tesi sulle convergenze e divergenze di queste aree di studio, sviluppando una rassegna della letteratura riguardante le alterazioni della temporalità nella schizofrenia e un lavoro sperimentale di osservazione dell'azione in pazienti ad esordio psicotico sul tema dell'intersoggettività.
La prima parte (Temporalità) inizia con un excursus storico sulle somiglianze e differenze della psicopatologia fenomenologica con le neuroscienze cognitive sul tema della percezione del tempo nella schizofrenia. Il lavoro si sviluppa ulteriormente con una revisione sistematica delle correlazioni tra le alterazioni della percezione del tempo nella schizofrenia e gli ambiti cognitivo, sintomatologico e neurobiologico. I risultati della nostra revisione ci consentono di delineare alcune considerazioni: 1) sembra che i deficit cognitivi della schizofrenia e l'alterazione della
temporalità nella schizofrenia appartengano a due domini distinti. 2) è più difficile stabilire se esiste o meno una chiara correlazione tra i sintomi positivi e negativi e i domini temporali 3) gli studi sul timing percettivo spiegano un'associazione primaria tra il deficit di timing con le disfunzioni dopaminergiche e fronto-striatali nella schizofrenia 4) gli studi sul timing motorio evidenziano un ruolo cruciale delle disfunzioni del circuito cerebello-talamo-corticale nell'elaborazione temporale.
La seconda parte (Intersoggettività) propone un lavoro sperimentale che cerca di creare un ponte tra la tradizione fenomenologica e le neuroscienze cognitive. I concetti sull'intersoggettività espressi dalla fenomenologia trovano una convergenza con la tesi della “direct social perception”. La “direct social perception” (DSP) è l'idea che possiamo percepire gli stati mentali degli altri. Questo tipo di percezione è diretta nel senso che non implica una mediazione inferenziale. Utilizzando un task di "action observation” abbiamo tentato di rilevare se ci sono differenze tra pazienti con disturbi psicotici e controlli sani nello svolgimento di compiti di decodifica dei parametri cinematici. I nostri risultati sottolineano che i pazienti hanno maggiori difficoltà rispetto ai controlli nell'interpretare il comportamento degli altri, specialmente quando vengono presentati con informazioni frammentate o parziali.Psychiatry, which has always been a border discipline, carries within itself different souls. Historically, some of the main contributions, particularly with regard to schizophrenia, have come from phenomenological psychopathology. This discipline, with its deep attention to the structures of experience, is being watched with increasing attention in order to limit the nosographic flattening of current diagnostic systems. On the other hand, the development of cognitive neuroscience now makes it essential, for a discipline that wants to maintain its boundaries within the medical sciences, to undergo the empirical validation of neurobiological constructs. I focused my thesis work on convergences and divergences of these disciplines, developing a review of the literature regarding the alterations of temporality in schizophrenia and an experimental work of action observation in psychotic onset patients on the subject of intersubjectivity. The first part (Temporality) begins with a historical study on the similarities and differences of phenomenological psychopathology and cognitive neuroscience on the topic of time perception in schizophrenia. The work develops further with the development of a systematic review of the correlations between alterations in the perception of time in schizophrenia and the cognitive, symptomatological and neurobiological domains. The results from our review allow us to outline some considerations: 1) it appears that the cognitive deficits of schizophrenia and the alteration of temporality in schizophrenia belong to two distinct domains. 2) it is more difficult to establish whether or not there is a clear correlation between the positive and negative symptoms and temporal domains 3) Studies regarding perceptual timing account for a primary association between timing deficit with dopaminergic and fronto-striatal dysfunctions in schizophrenia 4) Studies regarding motor timing highlight a crucial role of the cerebello-thalamo-cortical-circuit dysfunctions in subsecond temporal processing. The second part (Intersubjectivity) proposes an experimental work which try to set bridge between the phenomenological tradition and cognitive neuroscience. The concepts on intersubjectivity expressed by phenomenology find a convergence with the direct social perception thesis. Direct Social Perception (DSP) is the idea that we can perceive others’ mental states. This kind of perception is direct in the sense that it does not involve inferential mediation. Using an “action observation task” we attempted to detect whether there are differences between patients with psychotic disorders and healthy controls in carrying out tasks of decoding the kinematic parameters. Our results point out that patients have greater difficulty than controls in interpreting the behavior of others, especially when presented with fragmented or partial information.
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Ratwani, Raj M. "A spatial memory mechanism for guiding primary task resumption." Fairfax, VA : George Mason University, 2008. http://hdl.handle.net/1920/3082.
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Thesis (Ph.D.)--George Mason University, 2008.Vita: p. 78. Thesis director: J. Gregory Trafton. Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Psychology. Title from PDF t.p. (viewed July 3, 2008). Includes bibliographical references (p. 73-77). Also issued in print.
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Keeney, Jeriel T. "DOXORUBICIN-INDUCED, TNF-α-MEDIATED BRAIN OXIDATIVE STRESS, NEUROCHEMICAL ALTERATIONS, AND COGNITIVE DECLINE: INSIGHTS INTO MECHANISMS OF CHEMOTHERAPY INDUCED COGNITIVE IMPAIRMENT AND ITS PREVENTION." UKnowledge, 2013. http://uknowledge.uky.edu/chemistry_etds/27.
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The works presented in this dissertation provide insights into the mechanisms of chemotherapy-induced cognitive impairment (CICI or “ChemoBrain”) and take steps toward outlining a preventive strategy. CICI is now widely recognized as a complication of cancer chemotherapy experienced by a large percentage of cancer survivors. Approximately fifty percent of existing FDA-approved anti-cancer drugs generate reactive oxygen species (ROS). Doxorubicin (Dox), a prototypical ROS-generating chemotherapeutic agent, produces the reactive superoxide radical anion (O2-•) in vivo. Dox treatment results in oxidation of plasma proteins, including ApoA-I, leading to TNF-α-mediated oxidative stress in plasma and brain. TNF-α elevation in brain leads to further central nervous system toxicity including mitochondrial dysfunction, neuronal death, and cognitive impairment. Co-administration of the antioxidant drug, 2-mercaptoethane sulfonate sodium (MESNA), prevents Dox-induced protein oxidation and subsequent TNF-α elevation in plasma without interfering with the cancer-killing ability of Dox.
In studies presented in this dissertation, we measured oxidative stress in both brain and plasma of Dox-treated mice both with and without MESNA. MESNA ameliorated Dox-induced oxidative protein damage in plasma, confirming our prior studies, and in a new finding led to decreased oxidative stress in brain. Using novel object recognition (NOR), we demonstrated the Dox administration resulted in memory deficits. Using hydrogen magnetic resonance imaging spectroscopy (H1-MRS) techniques, we demonstrated that Dox administration led to a dramatic decrease in choline(phosphocholine)/creatine (Cho/Cr) ratios in mouse hippocampus. The activities of both phosphatidylcholine-specific phospholipase C (PC-PLC) and phospholipase D(PLD) were severely diminished following Dox administration. The activity of PC-PLC was preserved when MESNA was co-administered with Dox. In the absence of TNF-α, MRS-indexed Cho/Cr ratio, PLD activity, and mitochondrial oxygen consumption are preserved in brain, and markers of oxidative stress are reduced.
Together with results from our previous studies, these results provide strong evidence that TNF-α is strongly associated, if not responsible for CICI. We also tested the notion that O2-• is responsible for Dox-induced plasma protein oxidation and TNF-α release. O2-• resulted in increased oxidative damage to proteins when added to plasma and increased levels of TNF-α in macrophage culture, providing strong evidence that O2-• is responsible for these Dox-induced toxicities.
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Denham, Benjiman. "Gestural sense : art, neuroscience and linguistic embodiment." Thesis, View thesis, 2009. http://handle.uws.edu.au:8081/1959.7/46121.
Full textAbstract:
In introducing this work it’s useful to consider both the thematic threads that link the following chapters and the question of why an artist might choose to engage with the type of critical theoretical writing that is exemplified here. I will start by considering some of the threads that can be used to connect an eight year old reading Wittgenstein, “gesture-haptic writing”, freestyle poetry, and unaided human flight. Two questions can help in identifying those threads. Firstly, what can each of these subjects tell us about the ways in which language acts-on and alters bodies? And secondly what are the implications of those alterations for the process of speculating on how language and the body might continue in a particularly productive and creative relationship of co-evolution? Or, to put it in a slightly more linear fashion, how might various language-based creative practices be employed as agents in the continued evolution of the body.