889 resultados para Memories and visions


Relevância:

30.00% 30.00%

Publicador:

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Muscle is a major player in metabolism. It uses large amounts of glucose in the absorptive state and changes in muscle insulin-stimulated glucose uptake alter whole-body glucose disposal. Lipid substrates such as fatty acids or ketone bodies are preferentially used by muscle in certain physiological conditions. Muscle is also the main reservoir of amino acids and protein. The activity of many different plasma membrane transporters such as glucose carriers, carnitine, creatine or amino acid transporters maintain muscle metabolism by taking up or releasing substrates or metabolites across the cell surface. The goal of this review is the molecular characterization of muscle membrane transporter proteins and the analysis of their regulatory roles.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This dissertation analyses public opinion towards the welfare state across 29 European countries. Based on an interdisciplinary approach combining social psychological, sociological, and public opinion approaches to political opinion formation, it investigates how social position and shared beliefs shape perceived legitimacy of welfare institutions, and how social contexts impact on the processes of opinion formation. Drawing on social representations theory, as well as socialization and self-interest approaches, the dissertation analyses the role of social position in lay support for institutional solidarity. Normative beliefs-defined as preferred views regarding the organisation of social relations-mediate the effect of social position on welfare support. In addition, drawing on public opinion literature, the dissertation analyses opinion formation as a function of country-level structural (e.g., level of social spending, unemployment) and ideological factors (e.g., level of meritocracy). The dissertation comprises two theoretical and four empirical chapters. Three of the empirical chapters use data from the European Social Survey 2008. Using multilevel and typological approaches, the dissertation contributes to welfare attitude literature by showing that normative beliefs, such as distrust or egalitarianism, function as underlying mechanisms that link social position to policy attitudes (Chapter 3), and that characteristics of the national contexts influence the processes of political opinion formation (Chapters 3 and 4). Chapter 5 proposes and predicts a typology of the relationship between attitudes towards solidarity and attitudes towards control, reflecting the two central domains of government intervention. Finally, Chapter 6 examines welfare support in the realm of action and social protest, using data from a survey on Spanish Indigados activists. The findings of this dissertation inform contemporary debates about welfare state legitimacy and retrenchment. - Cette thèse avait pour but d'analyser l'opinion publique envers l'Etat social dans 29 pays européens. Basée sur une approche interdisciplinaire qui combine des perspectives psycho-sociales, sociologiques et d'opinion publique sur la formation d'opinion politique, la thèse étudie comment la position sociale et les croyances partagées façonnent la légitimité perçue des institutions de l'Etat social, et comment les contextes sociaux influencent les processus de formation d'opinion. Basée sur la théorie des représentations sociales, ainsi qu'une approche de socialisation et d'intérêt propre, cette thèse analyse le rôle des positions sociales dans le soutien envers la solidarité institutionnelle. Les croyances normatives-définies comme les visions préférées de l'organisation des rapports sociaux-médiatisent l'effet de la position sociale sur le soutien pour l'Etat social. De plus, s'inspirant de la littérature sur l'opinion publique, la thèse analyse la formation d'opinion en fonction des facteurs structurels (ex. le taux de dépenses sociales, le chômage) et idéologiques (ex. le degré de méritocratie). Cette thèse est composée de deux chapitres théoriques et quatre chapitres empiriques. Trois chapitres empiriques utilisent des données provenant de l'enquête European Social Survey 2008. Appliquant des approches multi-niveux et typoloqiques, la thèse contribue à la littérature sur les attitudes envers l'Etat social en montrant que les croyances normatives, telles que la méfiance ou l'égalitarisme, fonctionnent comme des mécanismes sous-jacents qui relient la position sociale aux attitudes politiques (Chapitre 3), et que les caractéristiques des contextes nationaux influencent les processus de formation d'opinion politique (Chapitres 3 et 4). Le chapitre 5 propose et prédit une typologie sur le rapport entre les attitudes envers la solidarité et celles envers le contrôle, renvoyant à deux domaines centraux de régulation étatique. Enfin, le chapitre 6 examine le soutien à l'Etat social dans le domaine de l'action protestataire, utilisant des données d'une enquête menée auprès des militants espagnols du mouvement des Indignés. Les résultats de cette thèse apportent des éléments qui éclairent les débats contemporains sur la légitimité de l'Etat social et son démantèlement.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The hippocampal formation is essential for the processing of episodic memories for autobiographical events that happen in unique spatiotemporal contexts. Interestingly, before 2 years of age, children are unable to form or store episodic memories for recall later in life, a phenomenon known as infantile amnesia. From 2 to 7 years of age, there are fewer memories than predicted based on a forgetting function alone, a phenomenon known as childhood amnesia. Here, we discuss the postnatal maturation of the primate hippocampal formation with the goal of characterizing the development of the neurobiological substrates thought to subserve the emergence of episodic memory. Distinct regions, layers and cells of the hippocampal formation exhibit different profiles of structural and molecular development during early postnatal life. The protracted period of neuronal addition and maturation in the dentate gyrus is accompanied by the late maturation of specific layers in different hippocampal regions that are located downstream from the dentate gyrus, particularly CA3. In contrast, distinct layers in several hippocampal regions, particularly CA1, which receive direct projections from the entorhinal cortex, exhibit an early maturation. In addition, hippocampal regions that are more highly interconnected with subcortical structures, including the subiculum, presubiculum, parasubiculum and CA2, mature even earlier. These findings, together with our studies of the development of human spatial memory, support the hypothesis that the differential maturation of distinct hippocampal circuits might underlie the differential emergence of specific "hippocampus-dependent" memory processes, culminating in the emergence of episodic memory concomitant with the maturation of all hippocampal circuits.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

For more than 80 years, visitors to the Iowa State Historical, Memorial, and Art Building were treated to the state’s collection of historic documents, literature, portraits, and historical, geological, and archeological artifacts. Those who visited might have memories of the spectacular sand paintings by Iowan Andrew Clemens, the variety of taxidermy Iowa animals, the pioneer Conestoga wagon in the basement, the biplane hanging from the dome ceiling, the odd display by the medical library of things removed from stomachs, or the Native American display on the third floor. This booklet is a look back at the origins of the museum. It includes some of the Historical Department reports, legislation passed by the general assembly, newspaper and magazine articles, and photographs pertaining to the museum and library. It is not intended to be an exhaustive review and documentation of displays and exhibits. It is a brief overview of the building’s history and some photographs that may bring back memories, for some, of a field trip as a student. This booklet has been created from a variety of source materials: photographs, newspaper articles, and various reports. The following have contributed: State Library of Iowa, Iowa State Historical Society, the Iowa Judicial Branch, Susan Wallace, Helen Dagley, Barb Corson, Jerome Thompson, Pam Rees, Georgiann Fischer, and Jason Mrachina.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Deficits in memory consolidation have been reported in adult patients with epilepsy but, not to our knowledge, in children. We report the long-term follow-up (9 y. o. to 18 y. o.) of a boy who suffered from temporal lobe epilepsy and underwent a left temporal lobectomy with amygdalo-hippocampal resection at the age of 10. He showed an abnormal forgetting rate when trying to encode new information and a significant deficit for retrieving remote episodic memories (when compared with his twin brother), both consistent with a consolidation disorder. His memory condition slightly improved after cessation of the epilepsy, nevertheless did not normalize. No standard memory assessment could pinpoint his memory problem, hence an adapted methodology was needed. We discuss the nature of the memory deficit, its possible causes and its clinical implications.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Aquest treball analitza la conquesta cristiana de Mallorca des de la comparació dels relats del Llibre dels fets, de Jaume I, la Crònica de Desclot i el Kitab Tarih Mayurqa de al-Mahzumi.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper demonstrates a novel distributed architecture to facilitate the acquisition of Language Resources. We build a factory that automates the stages involved in the acquisition, production, updating and maintenance of these resources. The factory is designed as a platform where functionalities are deployed as web services, which can be combined in complex acquisition chains using workflows. We show a case study, which acquires a Translation Memory for a given pair of languages and a domain using web services for crawling, sentence alignment and conversion to TMX.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Abstract The amygdala is a group of nuclei in the temporal lobe of the brain that plays a crucial role in anxiety and fear behavior. Sensory information converges in the basolateral and lateral nuclei of the amygdala, which have been the first regions in the brain where the acquisition of new (fear) memories has been associated with long term changes in synaptic transmission. These nuclei, in turn, project to the central nucleus of the amygdala. The central amygdala, through its extensive projections to numerous nuclei in the midbrain and brainstem, plays a pivotal role in the orchestration of the rapid autonomic and endocrine fear responses. In the central amygdala a large number of neuropeptides and receptors is expressed, among which high levels of vasopressin and oxytocin receptors. Local injections of these peptides into the amygdala modulate several aspects of the autonomic fear reaction. Interestingly, their effects are opposing: vasopressin tends to enhance the fear reactions, whereas oxytocin has anxiolytic effects. In order to investigate the neurophysiological mechanisms that could underlie this opposing modulation of the fear behavior, we studied the effects of vasopressin and oxytocin on the neuronal activity in an acute brain slice preparation of the rat central amygdala. We first assessed the effects of vasopressin and oxytocin on the spontaneous activity of central amygdala neurons. Extracellular single unit recordings revealed two major populations of neurons: a majority of neurons was excited by vasopressin and inhibited by oxytocin, whereas other neurons were only excited by oxytocin receptor activation. The inhibitory effect of oxytocin could be reduced by the block of GABAergic transmission, whereas the excitatory effects of vasopressin and oxytocin were not affected. In a second step we identified the cellular mechanisms for the excitatory effects of both peptides as well as the morphological and biochemical mechanisms underlying the opposing effects, by using sharp electrode recordings together with intracellular labelings. We revealed that oxytocin-excited neurons are localized in the lateral part (CeL) whereas vasopressin excited cells are found in the medial part of the central amygdala (CeM). The tracing of the neuronal morphology showed that the axon collaterals of the oxytocin-excited neurons project from the CeL, far into the CeM. Combined immunohistochemical stainings indicated that these projections are GABAergic. In the third set of experiments we investigated the synaptic interactions between the two identified cell populations. Whole-cell patch-clamp recordings in the CeM revealed that the inhibitory effect of oxytocin was caused by the massive increase of inhibitory GABAergic currents, which was induced by the activation of CeL neurons. Finally, the effects of vasopressin and oxytocin on evoked activity were investigated. We found on the one hand, that the probability of evoking action potentials in the CeM by stimulating the basolateral amygdala afferents was enhanced under vasopressin, whereas it decreased under oxytocin. On the other hand, the impact of cortical afferents stimulation on the CeL neurons was enhanced by oxytocin application. Taken together, these findings have allowed us to develop a model, in which the opposing behavioral effects of vasopressin and oxytocin are caused by a selective activation of two distinct populations of neurons in the GABAergic network of the central amygdala. Our model could help to develop new anxiolytic treatments, which modulate simultaneously both receptor systems. By acting on a GABAergic network, such treatments can further be tuned by combinations with classical benzodiazepines. Résumé: L'amygdale est un groupe de noyaux cérébraux localisés dans le lobe temporal. Elle joue un rôle essentiel dans les comportements liés à la peur et l'anxiété. L'information issue des aires sensorielles converge vers les noyaux amygdaliens latéraux et basolatéraux, qui sont les projections vers différents noyaux du tronc cérébral et de l'hypothalamus, joue un rôle clef premières régions dans lesquelles il a été démontré que l'acquisition d'une nouvelle mémoire (de peur) était associée à des changements à long terme de la transmission synaptique. Ces noyaux envoient leurs projections sur l'amygdale centrale, qui à travers ses propres dans l'orchestration des réponses autonomes et endocrines de peur. Le contrôle de l'activité neuronale dans l'amygdale centrale module fortement la réaction de peur. Ainsi, un grand nombre de neuropeptides sont spécifiquement exprimés dans l'amygdale centrale et un bon nombre d'entre eux interfère dans la réaction de peur et d'anxiété. Chez les rats, une forte concentration de récepteurs à l'ocytocine et à la vasopressine est exprimée dans le noyau central, et l'injection de ces peptides dans l'amygdale influence différents aspects de la réaction viscérale associée à la peur. Il est intéressant de constater que ces peptides exercent des effets opposés. Ainsi, la vasopressine augmente la réaction de peur alors que l'ocytocine a un effet anxiolytique. Afin d'investiguer les mécanismes neurophysiologiques responsables de ces effets opposés, nous avons étudié l'effet de la vasopressine et de l'ocytocine sur l'activité neuronale de préparations de tranches de cerveau de rats contenant entre autres de l'amygdale centrale. Tout d'abord, notre intérêt s'est porté sur les effets de ces deux neuropeptides sur l'activité spontanée dans l'amygdale centrale. Des enregistrements extracellulaires ont révélé différentes populations de neurones ; une majorité était excitée par la vasopressine et inhibée par l'ocytocine ; d'autres étaient seulement excités par l'activation du récepteur à l'ocytocine. L'effet inhibiteur de l'ocytocine a pu être réduit par l'inhibition de la transmission GABAergique, alors que ses effets excitateurs n'étaient pas affectés. Dans un deuxième temps, nous avons identifié les mécanismes cellulaires responsables de l'effet excitateur de ces deux peptides et analysé les caractéristiques morphologiques et biochimiques des neurones affectés. Des enregistrements intracellulaires ont permis de localiser les neurones excités par l'ocytocine dans la partie latérale de l'amygdale centrale (CeL), et ceux excités par la vasopressine dans sa partie médiale (CeM). Le traçage morphologique des neurones a révélé que les collatérales axonales des cellules excitées par l'ocytocine projetaient du CeL loin dans le CeM. De plus, des colorations immuno-histochimiques ont révélé que ces projections étaient GABAergiques. Dans un troisième temps, nous avons étudié les interactions synaptiques entre ces deux populations de cellules. Les enregistrements en whole-cell patch-clamp dans le CeM ont démontré que les effets inhibiteurs de l'ocytocine résultaient de l'augmentation massive des courants GABAergique résultant de l'activation des neurones dans le CeL. Finalement, les effets de l'ocytocine et de la vasopressine sur l'activité évoquée ont été étudiés. Nous avons pu montrer que la probabilité d'évoquer un potentiel d'action dans le CeM, par stimulation de l'amygdale basolatérale, était augmentée sous l'effet de la vasopressine et diminuée sous l'action de l'ocytocine. Par contre, l'impact de la stimulation des afférences corticales sur les neurones du CeL était augmenté par l'application de l'ocytocine. L'ensemble de ces résultats nous a permis de développer un modèle dans lequel les effets comportementaux opposés de la vasopressine et de l'ocytocine sont causés par une activation sélective des deux différentes populations de neurones dans un réseau GABAergique. Un tel modèle pourrait mener au développement de nouveaux traitements anxiolytiques en modulant l'activité des deux récepteurs simultanément. En agissant sur un réseau GABAergique, les effets d'un tel traitement pourraient être rendus encore plus sélectifs en association avec des benzodiazépines classiques.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

According to Ray Harryhausen, a special effects expert in the film industry, "Gustave Doré would have made a great director of photography . . . He saw things from the point of view of the camera." Doré's work has had a permanent impact on the imaginative realm of film since its very early days. In return, the silver screen has etched Doré into the 20th century imagination. Almost every film about the Bible since The Life and Passion of Jesus Christ produced by Pathé in 1902 refers to his illustrations, and every film adaptation of Dante or Don Quixote has used him as a model, from Georg Wilhelm Pabst and Orson Welles to Terry Gilliam. All films dealing with life in London in the Victorian era by directors ranging from David Lean, to Roman Polanski and Tim Burton draw on the visions in London: a pilgrimage for their sets. A large number of dream fantastical or phantasmagorical scenes take their inspiration from Doré's graphic world, beginning with Georges Méliès' A Trip to the Moon in 1902. In the realm of cartoons and animation, Walt Disney owes a huge debt to Doré. Doré primal forests, from Atala in particular, were also used in the various versions of King Kong from 1933 to the 2005 film by Peter Jackson, who had already drawn on Doré for The Lord of the Rings. Jean Cocteau was also indebted to the illustrations for Perrault's Fairy Tales for his Beauty and the Beast (1945), as was George Lucas for the character Chewbacca in Star Wars (1977) and even the Harry Potter film series. Through his influence on film history, Doré shaped the mass culture imagination.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

1 Summary This dissertation deals with two major aspects of corporate governance that grew in importance during the last years: the internal audit function and financial accounting education. In three essays, I contribute to research on these topics which are embedded in the broader corporate governance literature. The first two essays consist of experimental investigations of internal auditors' judgments. They deal with two research issues for which accounting research lacks evidence: The effectiveness of internal controls and the potentially conflicting role of the internal audit function between management and the audit committee. The findings of the first two essays contribute to the literature on internal auditors' judgment and the role of the internal audit function as a major cornerstone of corporate governance. The third essay theoretically examines a broader issue but also relates to the overall research question of this dissertation: What contributes to effective corporate governance? This last essay takes the perspective that the root for quality corporate governance is appropriate financial accounting education. r develop a public interest approach to accounting education that contributes to the literature on adequate accounting education with respect to corporate governance and accounting harmonization. The increasing importance of both the internal audit function and accounting education for corporate governance can be explained by the same recent fundamental changes that still affect accounting research and practice. First, the Sarbanes-Oxley Act of 2002 (SOX, 2002) and the 8th EU Directive (EU, 2006) have led to a bigger role for the internal audit function in corporate governance. Their implications regarding the implementation of audit committees and their oversight over internal controls are extensive. As a consequence, the internal audit function has become increasingly important for corporate governance and serves a new master (i.e. the audit committee) within the company in addition to management. Second, the SOX (2002) and the 8th EU Directive introduced additional internal control mechanisms that are expected to contribute to the reliability of financial information. As a consequence, the internal audit function is expected to contribute to a greater extent to the reliability of financial statements. Therefore, effective internal control mechanisms that strengthen objective judgments and independence become important. This is especially true when external- auditors rely on the work of internal auditors in the context of the International Standard on Auditing (ISA) 610 and the equivalent US Statement on Auditing Standards (SAS) 65 (see IFAC, 2009 and AICPA, 1990). Third, the harmonization of international reporting standards is increasingly promoted by means of a principles-based approach. It is the leading approach since a study of the SEC (2003) that was required by the SOX (2002) in section 108(d) was in favor of this approach. As a result, the Financial Accounting Standards Board (FASB) and the International Accounting Standards Board (IASB) commit themselves to the development of compatible accounting standards based on a principles-based approach. Moreover, since the Norwalk Agreement of 2002, the two standard setters have developed exposure drafts for a common conceptual framework that will be the basis for accounting harmonization. The new .framework will be in favor of fair value measurement and accounting for real-world economic phenomena. These changes in terms of standard setting lead to a trend towards more professional judgment in the accounting process. They affect internal and external auditors, accountants, and managers in general. As a consequence, a new competency set for preparers and users of financial statements is required. The basil for this new competency set is adequate accounting education (Schipper, 2003). These three issues which affect corporate governance are the initial point of this dissertation and constitute its motivation. Two broad questions motivated a scientific examination in three essays: 1) What are major aspects to be examined regarding the new role of the internal audit function? 2) How should major changes in standard setting affect financial accounting education? The first question became apparent due to two published literature reviews by Gramling et al. (2004) and Cohen, Krishnamoorthy & Wright (2004). These studies raise various questions for future research that are still relevant and which motivate the first two essays of my dissertation. In the first essay, I focus on the role of the internal audit function as one cornerstone of corporate governance and its potentially conflicting role of serving both management and the audit committee (IIA, 2003). In an experimental study, I provide evidence on the challenges for internal auditors in their role as servant for two masters -the audit committee and management -and how this influences internal auditors' judgment (Gramling et al. 2004; Cohen, Krishnamoorthy & Wright, 2004). I ask if there is an expectation gap between what internal auditors should provide for corporate governance in theory compared to what internal auditors are able to provide in practice. In particular, I focus on the effect of serving two masters on the internal auditor's independence. I argue that independence is hardly achievable if the internal audit function serves two masters with conflicting priorities. The second essay provides evidence on the effectiveness of accountability as an internal control mechanism. In general, internal control mechanisms based on accountability were enforced by the SOX (2002) and the 8th EU Directive. Subsequently, many companies introduced sub-certification processes that should contribute to an objective judgment process. Thus, these mechanisms are important to strengthen the reliability of financial statements. Based on a need for evidence on the effectiveness of internal control mechanisms (Brennan & Solomon, 2008; Gramling et al. 2004; Cohen, Krishnamoorthy & Wright, 2004; Solomon & Trotman, 2003), I designed an experiment to examine the joint effect of accountability and obedience pressure in an internal audit setting. I argue that obedience pressure potentially can lead to a negative influence on accountants' objectivity (e.g. DeZoort & Lord, 1997) whereas accountability can mitigate this negative effect. My second main research question - How should major changes in standard setting affect financial accounting education? - is investigated in the third essay. It is motivated by the observation during my PhD that many conferences deal with the topic of accounting education but very little is published about what needs to be done. Moreover, the Endings in the first two essays of this thesis and their literature review suggest that financial accounting education can contribute significantly to quality corporate governance as argued elsewhere (Schipper, 2003; Boyce, 2004; Ghoshal, 2005). In the third essay of this thesis, I therefore focus on approaches to financial accounting education that account for the changes in standard setting and also contribute to corporate governance and accounting harmonization. I argue that the competency set that is required in practice changes due to major changes in standard setting. As the major contribution of the third article, I develop a public interest approach for financial accounting education. The major findings of this dissertation can be summarized as follows. The first essay provides evidence to an important research question raised by Gramling et al. (2004, p. 240): "If the audit committee and management have different visions for the corporate governance role of the IAF, which vision will dominate?" According to the results of the first essay, internal auditors do follow the priorities of either management or the audit committee based on the guidance provided by the Chief Audit executive. The study's results question whether the independence of the internal audit function is actually achievable. My findings contribute to research on internal auditors' judgment and the internal audit function's independence in the broader frame of corporate governance. The results are also important for practice because independence is a major justification for a positive contribution of the internal audit function to corporate governance. The major findings of the second essay indicate that the duty to sign work results - a means of holding people accountable -mitigates the negative effect of obedience pressure on reliability. Hence, I found evidence that control .mechanisms relying on certifications may enhance the reliability of financial information. These findings contribute to the literature on the effectiveness of internal control mechanisms. They are also important in the light of sub-certification processes that resulted from the Sarbanes-Oxley Act and the 8th EU Directive. The third essay contributes to the literature by developing a measurement framework that accounts for the consequences of major trends in standard setting. Moreovér, it shows how these trends affect the required .competency set of people dealing with accounting issues. Based on this work, my main contribution is the development of a public interest approach for the design of adequate financial accounting curricula. 2 Serving two masters: Experimental evidence on the independence of internal auditors Abstract Twenty nine internal auditors participated in a study that examines the independence of internal auditors in their potentially competing roles of serving two masters: the audit committee and management. Our main hypothesis suggests that internal auditors' independence is not achievable in an institutional setting in which internal auditors are accountable to two different parties with potentially differing priorities. We test our hypothesis in an experiment in which the treatment consisted of two different instructions of the Chief audit executive; one stressing the priority of management (cost reduction) and one stressing the priority of the audit committee (effectiveness). Internal auditors had to evaluate internal controls and their inherent costs of different processes which varied in their degree of task complexity. Our main results indicate that internal auditors' evaluation of the processes is significantly different when task complexity is high. Our findings suggest that internal auditors do follow the priorities of either management or the audit committee depending on the instructions of a superior internal auditor. The study's results question whether the independence of the internal audit function is actually achievable. With our findings, we contribute to research on internal auditors' judgment and the internal audit function's independence in the frame of corporate governance.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Ja fa uns anys des que J. Miró va publicar el seu llibre sobre les àmfores de la Tarraconense; des d’aleshores noves proves han canviat el panorama d’aquestes àmfores romanes catalanes. El present article tracta d’actualitzar el nostre coneixement actual sobre la pauta de consum i de distribució d’aquests envasos. Nous mètodes i dades quantificades i ben datades (per exemple, segells i fragments d’àmfora) ens permeten reconsiderar la distribució d’aquesta àmfora per l’occident de l’Imperi romà.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Single-trial encounters with multisensory stimuli affect both memory performance and early-latency brain responses to visual stimuli. Whether and how auditory cortices support memory processes based on single-trial multisensory learning is unknown and may differ qualitatively and quantitatively from comparable processes within visual cortices due to purported differences in memory capacities across the senses. We recorded event-related potentials (ERPs) as healthy adults (n = 18) performed a continuous recognition task in the auditory modality, discriminating initial (new) from repeated (old) sounds of environmental objects. Initial presentations were either unisensory or multisensory; the latter entailed synchronous presentation of a semantically congruent or a meaningless image. Repeated presentations were exclusively auditory, thus differing only according to the context in which the sound was initially encountered. Discrimination abilities (indexed by d') were increased for repeated sounds that were initially encountered with a semantically congruent image versus sounds initially encountered with either a meaningless or no image. Analyses of ERPs within an electrical neuroimaging framework revealed that early stages of auditory processing of repeated sounds were affected by prior single-trial multisensory contexts. These effects followed from significantly reduced activity within a distributed network, including the right superior temporal cortex, suggesting an inverse relationship between brain activity and behavioural outcome on this task. The present findings demonstrate how auditory cortices contribute to long-term effects of multisensory experiences on auditory object discrimination. We propose a new framework for the efficacy of multisensory processes to impact both current multisensory stimulus processing and unisensory discrimination abilities later in time.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Since Damasio introduced the somatic markers hypothesis in Damasio (1994), it has spread through the psychological community, where it is now commonly acknowledged that somatic states are a factor in producing the qualitative dimension of our experiences. Present actions are emotionally guided by those somatic states that were previously activated in similar experiences. In this model, somatic markers serve as a kind of embodied memory. Here, we test whether the manipulation of somatic markers can modulate the emotional evaluation of negative memories. Because facial feedback has been shown to be a powerful means of modifying emotional judgements, we used it to manipulate somatic markers. Participants first read a sad story in order to induce a negative emotional memory and then were asked to rate their emotions and memory about the text. Twenty-four hours later, the same participants were asked to assume a predetermined facial feedback (smiling) while reactivating their memory of the sad story. The participants were once again asked to fill in emotional and memory questionnaires about the text. Our results showed that participants who had smiled during memory reactivation later rated the text less negatively than control participants. However, the contraction of the zygomaticus muscles during memory reactivation did not have any impact on episodic memory scores. This suggests that manipulating somatic states modified emotional memory without affecting episodic memory. Thus, modulating memories through bodily states might pave the way to studying memory as an embodied function and help shape new kinds of psychotherapeutic interventions.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background: Being physically assaulted is known to increase the risk of the occurrence of post-traumatic stress disorder (PTSD) symptoms but it may also skew judgements about the intentions of other people. The objectives of the study were to assess paranoia and PTSD after an assault and to test whether theory-derived cognitive factors predicted the persistence of these problems. Method: At 4 weeks after hospital attendance due to an assault, 106 people were assessed on multiple symptom measures (including virtual reality) and cognitive factors from models of paranoia and PTSD. The symptom measures were repeated 3 and 6 months later. Results: Factor analysis indicated that paranoia and PTSD were distinct experiences, though positively correlated. At 4 weeks, 33% of participants met diagnostic criteria for PTSD, falling to 16% at follow-up. Of the group at the first assessment, 80% reported that since the assault they were excessively fearful of other people, which over time fell to 66%. Almost all the cognitive factors (including information-processing style during the trauma, mental defeat, qualities of unwanted memories, self-blame, negative thoughts about self, worry, safety behaviours, anomalous internal experiences and cognitive inflexibility) predicted later paranoia and PTSD, but there was little evidence of differential prediction. Conclusions: Paranoia after an assault may be common and distinguishable from PTSD but predicted by a strikingly similar range of factors.