5,473 research outputs found

    An investigation of entorhinal spatial representations in self-localisation behaviours

    Get PDF
    Spatial-modulated cells of the medial entorhinal cortex (MEC) and neighbouring cortices are thought to provide the neural substrate for self-localisation behaviours. These cells include grid cells of the MEC which are thought to compute path integration operations to update self-location estimates. In order to read this grid code, downstream cells are thought to reconstruct a positional estimate as a simple rate-coded representation of space. Here, I show the coding scheme of grid cell and putative readout cells recorded from mice performing a virtual reality (VR) linear location task which engaged mice in both beaconing and path integration behaviours. I found grid cells can encode two unique coding schemes on the linear track, namely a position code which reflects periodic grid fields anchored to salient features of the track and a distance code which reflects periodic grid fields without this anchoring. Grid cells were found to switch between these coding schemes within sessions. When grid cells were encoding position, mice performed better at trials that required path integration but not on trials that required beaconing. This result provides the first mechanistic evidence linking grid cell activity to path integration-dependent behaviour. Putative readout cells were found in the form of ramp cells which fire proportionally as a function of location in defined regions of the linear track. This ramping activity was found to be primarily explained by track position rather than other kinematic variables like speed and acceleration. These representations were found to be maintained across both trial types and outcomes indicating they likely result from recall of the track structure. Together, these results support the functional importance of grid and ramp cells for self-localisation behaviours. Future investigations will look into the coherence between these two neural populations, which may together form a complete neural system for coding and decoding self-location in the brain

    The Influence of Neuroendocrine and Genetic Markers of Stress on Cognitive Processing and Intrusive Symptoms

    Full text link
    This body of research investigated the influence of neuroendocrine and genetic elements of arousal on cognitive processes in the development of intrusive memories and flash-forward intrusions as related to Post-Traumatic Stress Disorder. Specifically, this thesis investigated various mechanisms that may underlie intrusive symptoms as postulated by prevalent theories of PTSD. Study 1 examined the distinctive relationship between peritraumatic dissociation and subsequent re-experiencing symptoms. Network analyses revealed strong positive edges between peritraumatic dissociation and subsequent amnesia, as well as the re-experiencing symptoms of physical reactivity to reminders, flashbacks, intrusions, and dreams, and to a lesser extent emotional numbness and hypervigilance. The finding that peritraumatic dissociation is related to subsequent re-experiencing symptoms is consistent with cognitive models that emphasize the role of dissociative experiences during a traumatic event in the etiology of PTSD re-experiencing symptoms. Study 2 aimed to determine whether peri-traumatic stress, as measured via salivary cortisol and salivary alpha-amylase, as well as pre-existing genetic polymorphisms on the FKBP5 gene increased dissociation and data-driven processing, and subsequently impacted intrusive memories related to a trauma film. The findings revealed that greater noradrenergic arousal predicted less intrusive memory distress in individuals who scored higher on data-driven processing and trait dissociation, and in FKBP5 low-risk carriers. For individuals who reported less data-driven processing and trait dissociation, and in FKBP5 high-risk carriers, as noradrenergic arousal increased, intrusive memory distress increased. This study also showed no association between data-driven processing with memory fragmentation, and fragmentation with intrusive memories. Whilst these findings support some aspect of cognitive models of PTSD as they indicate a role for data-driven processing and dissociation in intrusive symptoms, they highlight a threshold at which these variables stop moderating the relationship between arousal and intrusive memories and suggest that memory fragmentation is not related to intrusive memories. Study 3 examined the role of cognitive control in flash-forward intrusions in the context of an enduring stressor, the COVID-19 pandemic. In line with expectations, results showed that as cognitive control worsened, FKBP5 high-risk carriers reported more flash-forward distress, and low-risk carriers reported less distress. These findings are considered in the context of hippocampal changes and are consistent with emerging theories of PTSD. Lastly, study 4 sought to investigate the role of two neurological processes, pattern separation and pattern completion in intrusive memories in individuals with PTSD compared to trauma exposed controls. Consistent with existing literature, the data indicate that individuals with PTSD reported more data-driven processing, more intrusive symptoms, and demonstrated better behavioural pattern completion than trauma-exposed controls. These findings are in line with current cognitive models of PTSD, as they again indicate a role for data-driven processing in PTSD. However, study 4 found no support for the postulate that deficient pattern separation is a feature of PTSD and found an opposite effect for the role of pattern completion. Whilst these findings are inconsistent with theory, they are in line with existing experimental studies. Overall, the findings from this thesis provide insight into cognitive and biological models of PTSD and shed light on the mechanisms underlying the nature and development of intrusive symptoms

    Exploring cognitive mechanisms involved in self-face recognition

    Get PDF
    Due to the own face being a significant stimulus that is critical to one’s identity, the own face is suggested to be processed in a quantitatively different (i.e., faster and better recognition) and qualitatively different (i.e., processed in a more featural manner) manner compared to other faces. This thesis further explored the cognitive mechanisms (perceptual and attentional systems) involved in the processing of the own face. Chapter 2 explored the role of holistic and featural processing involved in the processing of self-face (and other faces) with eye-tracking measures in a passive-viewing paradigm and a face identification task. In the passive-viewing paradigm, the own face was sampled in a more featural manner compared to other faces whereas when asked to identify faces, all faces were sampled in a more holistic manner. Chapter 3 further explored the role of holistic and featural processing in the identification of the own face using the three standard measures of holistic face processing: The face inversion task, the composite face task, and the part-whole task. Compared to other faces, individuals showed a smaller “holistic interference” by a task irrelevant bottom half for the own face in the composite face task and a stronger feature advantage for the own face, but inversion impaired the identification of all faces. These findings suggest that self-face is processed in a more featural manner, but the findings do not deny the role of holistic processing. The final experimental chapter, Chapter 4, explored the modulation effects of cultural differences in one’s self-concept (i.e., independent vs. interdependent self-concept) and a negative self-concept (i.e., depressive traits) on the attentional prioritization for the own face with a visual search paradigm. Findings showed that the attentional prioritization for the own face over an unfamiliar face is not modulated by cultural differences of one’s self-concept nor one’s level of depressive traits, and individuals showed no difference in the attentional prioritization for both the own face and friend’s face, demonstrating no processing advantage for the own face over a personally familiar face. These findings suggests that the attentional prioritization for the own face is better explained by a familiar face advantage. Altogether, the findings of this thesis suggest that the own face is processed qualitatively different compared to both personally familiar and unfamiliar face, with the own face being processed in a more featural manner. However, in terms of quantitative differences, the self-face is processed differently compared to an unfamiliar face, but not to a familiar face. Although the specific face processing strategies for the own face may be due to the distinct visual experience that one has with their face, the attentional prioritization of the own face is however, better explained by a familiar face advantage rather than a self-specificity effect

    Looking before we leap: Expanding ethical review processes for AI and data science research

    Get PDF
    This is the final version. Available from The Ada Lovelace Institute via the DOI in this record. As part of this work, the Ada Lovelace Institute, the University of Exeter’s Institute for Data Science and Artificial Intelligence, and the Alan Turing Institute developed six mock AI and data science research proposals that represent hypothetical submissions to a Research Ethics Committee. An expert workshop found that case studies are useful training resources for understanding common AI and data science ethical challenges. Their purpose is to prompt reflection on common research ethics issues and the societal implications of different AI and data science research projects. These case studies are for use by students, researchers, members of research ethics committees, funders and other actors in the research ecosystem to further develop their ability to spot and evaluate common ethical issues in AI and data science research.Alan Turing InstituteArts and Humanities Research Counci

    Cortical processing during robot and functional electrical stimulation

    Get PDF
    IntroductionLike alpha rhythm, the somatosensory mu rhythm is suppressed in the presence of somatosensory inputs by implying cortical excitation. Sensorimotor rhythm (SMR) can be classified into two oscillatory frequency components: mu rhythm (8–13 Hz) and beta rhythm (14–25 Hz). The suppressed/enhanced SMR is a neural correlate of cortical activation related to efferent and afferent movement information. Therefore, it would be necessary to understand cortical information processing in diverse movement situations for clinical applications.MethodsIn this work, the EEG of 10 healthy volunteers was recorded while fingers were moved passively under different kinetic and kinematic conditions for proprioceptive stimulation. For the kinetics aspect, afferent brain activity (no simultaneous volition) was compared under two conditions of finger extension: (1) generated by an orthosis and (2) generated by the orthosis simultaneously combined and assisted with functional electrical stimulation (FES) applied at the forearm muscles related to finger extension. For the kinematic aspect, the finger extension was divided into two phases: (1) dynamic extension and (2) static extension (holding the extended position).ResultsIn the kinematic aspect, both mu and beta rhythms were more suppressed during a dynamic than a static condition. However, only the mu rhythm showed a significant difference between kinetic conditions (with and without FES) affected by attention to proprioception after transitioning from dynamic to static state, but the beta rhythm was not.DiscussionOur results indicate that mu rhythm was influenced considerably by muscle kinetics during finger movement produced by external devices, which has relevant implications for the design of neuromodulation and neurorehabilitation interventions

    Healthcare when the bets are off : symptoms, trajectories and treatment of individuals with gambling disorder

    Get PDF
    Gambling Disorder is a debilitating condition associated with several adverse outcomes. Despite available treatment, most of those suffering never seek help and those that do often present a complex clinical picture with a long duration of gambling problems and additional psychiatric disorders. Currently, there are several gaps in knowledge about this patient population, the care provided within addiction services, and the long-term consequences for these individuals in terms of functionality and work life. The current thesis, therefore, aims to address some of these gaps, with the goal of increasing knowledge about the patient group and improving treatments. In addition, when disseminating scientifically evaluated treatment to clinical practice, the problem gambling counselor plays an important role. What treatments are actually offered, by whom, and the role of the counselor has not previously been explored. Moreover, factors contributing to the development and maintenance of GD have been proposed and deserve further investigation; gambling cravings and difficulties in emotion regulation. Therefore, the overall aim of this thesis is to map the harms of GD, the treatment available and the characteristics of those delivering it, and track changes in gambling during the Covid-19 pandemic. Furthermore, the thesis aims to explore individual factors contributing to maintaining the disorder, i.e., craving and difficulties in emotion regulation. Study I is a case-cohort study using merged national registries to investigate GD’s association with work disability and trajectory groups in a longitudinal design over a sixyear period. The results showed that GD is associated with an increased risk of work disability over a four-year period, starting the year before diagnosis and peaking at the time of diagnosis (AOR = 1.89, 95% CIs = 1.67-2.13). The risk was unevenly distributed: females, those with psychiatric comorbidities or having medicated for psychiatric symptoms, and older individuals were at higher risk of work disability. The results add knowledge to what social and financial harms are associated with GD. Study II maps available treatment in a cross-sectional study surveying practicing PG counselors. This study found that CBT and MI are the most frequently offered treatments and that treating more clients monthly is associated with higher adequacy (OR = 1.49, 95% CIs = 1.12 -1.95), legitimacy (OR = 1.38, 95% CIs = 1.08 – 1.75), and willingness (OR = 1.95, 95% CIs = 1.49-2.61 in their role as PG counselors. Standard CBT techniques and addressing motivation were rated as the most important to include in treatment. Notable, most PG counselors (>70%) saw fewer than two clients monthly with PG. Study III is a qualitative study applying thematic analysis to interviews of individuals with GD or alcohol use disorder, all with recent experiences of craving, and exploring content and modes of thought when craving. Participants described their cravings as dominated by mental imagery often involving positive content of anticipation, carrying out the addictive behavior or expected outcomes. Craving for alcohol was more related to seeking relief and craving for gambling to gain financial assets. Study IV evaluated the feasibility of a transdiagnostic intervention, emotion regulation-enhanced CBT, among treatment seekers in addiction care using a mixed methods design. Participants improved on gambling outcomes: a decrease in symptoms of GD from a pretreatment mean of 7.0 to 2.1 at 12 months follow-up and a reduction in gambling expenditure and comorbid symptoms of depression and anxiety. In addition, participants rated the treatment high in acceptance and credibility, and interviews indicated that individual tailoring and prolongation as potential improvements. Adding emotion regulation to the treatment of GD is feasible and deserves further investigation. Study V investigated changes in gambling behavior during the Covid-19 pandemic in a cohort recruited from social media and a gambling helpline. We did not find associations between pandemic restrictions and increased problem gambling, worries about mental health due to the pandemic (OR = 2.85, p < 0.001), and initiating high-risk gambling formats (OR = 7.44, p < 0.001), such as online casino, were associated with PG. We did not observe any significant migrations between gambling formats despite the change in availability during the initial phase of the pandemic. In conclusion, the findings demonstrate that GD is associated with an elevated risk of work disability, CBT and MI are treatments available, but PG counselors seem to lack important clinical practice; cravings are often experienced as mental imagery of anticipation, and emotion regulation could be added to the clinical toolbox in the treatment for GD and deserves further investigation. In addition, Swedish pandemic restrictions did not seem to have been linked to increased gambling, but those initiating a high-risk gambling format or being worried about their mental health during the pandemic were more likely to develop PG

    Corporate Social Responsibility: the institutionalization of ESG

    Get PDF
    Understanding the impact of Corporate Social Responsibility (CSR) on firm performance as it relates to industries reliant on technological innovation is a complex and perpetually evolving challenge. To thoroughly investigate this topic, this dissertation will adopt an economics-based structure to address three primary hypotheses. This structure allows for each hypothesis to essentially be a standalone empirical paper, unified by an overall analysis of the nature of impact that ESG has on firm performance. The first hypothesis explores the evolution of CSR to the modern quantified iteration of ESG has led to the institutionalization and standardization of the CSR concept. The second hypothesis fills gaps in existing literature testing the relationship between firm performance and ESG by finding that the relationship is significantly positive in long-term, strategic metrics (ROA and ROIC) and that there is no correlation in short-term metrics (ROE and ROS). Finally, the third hypothesis states that if a firm has a long-term strategic ESG plan, as proxied by the publication of CSR reports, then it is more resilience to damage from controversies. This is supported by the finding that pro-ESG firms consistently fared better than their counterparts in both financial and ESG performance, even in the event of a controversy. However, firms with consistent reporting are also held to a higher standard than their nonreporting peers, suggesting a higher risk and higher reward dynamic. These findings support the theory of good management, in that long-term strategic planning is both immediately economically beneficial and serves as a means of risk management and social impact mitigation. Overall, this contributes to the literature by fillings gaps in the nature of impact that ESG has on firm performance, particularly from a management perspective

    Examples of works to practice staccato technique in clarinet instrument

    Get PDF
    Klarnetin staccato tekniğini güçlendirme aşamaları eser çalışmalarıyla uygulanmıştır. Staccato geçişlerini hızlandıracak ritim ve nüans çalışmalarına yer verilmiştir. Çalışmanın en önemli amacı sadece staccato çalışması değil parmak-dilin eş zamanlı uyumunun hassasiyeti üzerinde de durulmasıdır. Staccato çalışmalarını daha verimli hale getirmek için eser çalışmasının içinde etüt çalışmasına da yer verilmiştir. Çalışmaların üzerinde titizlikle durulması staccato çalışmasının ilham verici etkisi ile müzikal kimliğe yeni bir boyut kazandırmıştır. Sekiz özgün eser çalışmasının her aşaması anlatılmıştır. Her aşamanın bir sonraki performans ve tekniği güçlendirmesi esas alınmıştır. Bu çalışmada staccato tekniğinin hangi alanlarda kullanıldığı, nasıl sonuçlar elde edildiği bilgisine yer verilmiştir. Notaların parmak ve dil uyumu ile nasıl şekilleneceği ve nasıl bir çalışma disiplini içinde gerçekleşeceği planlanmıştır. Kamış-nota-diyafram-parmak-dil-nüans ve disiplin kavramlarının staccato tekniğinde ayrılmaz bir bütün olduğu saptanmıştır. Araştırmada literatür taraması yapılarak staccato ile ilgili çalışmalar taranmıştır. Tarama sonucunda klarnet tekniğin de kullanılan staccato eser çalışmasının az olduğu tespit edilmiştir. Metot taramasında da etüt çalışmasının daha çok olduğu saptanmıştır. Böylelikle klarnetin staccato tekniğini hızlandırma ve güçlendirme çalışmaları sunulmuştur. Staccato etüt çalışmaları yapılırken, araya eser çalışmasının girmesi beyni rahatlattığı ve istekliliği daha arttırdığı gözlemlenmiştir. Staccato çalışmasını yaparken doğru bir kamış seçimi üzerinde de durulmuştur. Staccato tekniğini doğru çalışmak için doğru bir kamışın dil hızını arttırdığı saptanmıştır. Doğru bir kamış seçimi kamıştan rahat ses çıkmasına bağlıdır. Kamış, dil atma gücünü vermiyorsa daha doğru bir kamış seçiminin yapılması gerekliliği vurgulanmıştır. Staccato çalışmalarında baştan sona bir eseri yorumlamak zor olabilir. Bu açıdan çalışma, verilen müzikal nüanslara uymanın, dil atış performansını rahatlattığını ortaya koymuştur. Gelecek nesillere edinilen bilgi ve birikimlerin aktarılması ve geliştirici olması teşvik edilmiştir. Çıkacak eserlerin nasıl çözüleceği, staccato tekniğinin nasıl üstesinden gelinebileceği anlatılmıştır. Staccato tekniğinin daha kısa sürede çözüme kavuşturulması amaç edinilmiştir. Parmakların yerlerini öğrettiğimiz kadar belleğimize de çalışmaların kaydedilmesi önemlidir. Gösterilen azmin ve sabrın sonucu olarak ortaya çıkan yapıt başarıyı daha da yukarı seviyelere çıkaracaktır
    corecore