384 resultados para RESPONSE-INHIBITION TASK


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The drought Australia now faces is leading to shifts in the perception of the continent, of Australians and the world. The ideals of lush green landscapes are making way for landscape designs in which dryness is a quality of the design. On a map of the world, Australia is enormous, and seems empty because development is concentrated around its edges. Its heart must be red, in the cultural projections of the world from images of Uluru, 'the rock', set in a flat desert with no relief. Of course the country is not really all desert - surely? - with low shrubs pretty much throughout. Inhabitation seems to cling to the edges where teh continent feels microclimatic effects from the adjacent oceans and edging mountain ranges, which screen the population from the real state of the environment - dry, harsh, amazing and unique. Australia is rightly proud of this harsh difference from its edges, but prefers the harshness to be 'out there'. At the moment however, the country is pretty much universally in drought, and the contrast between green and brown, that it has celebrated, even built its identity around, is disappearing to become brown throughout. Without the browning of Australia, some areas, such as tropical Queensland, are having their designed public landscapes and gardens revealed as an elaborate mythology, a landscape fraud.

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Objectives. Intrusive memories of extreme trauma can disrupt a stepwise approach to imaginal exposure. Concurrent tasks that load the visuospatial sketchpad (VSSP) of working memory reduce the vividness of recalled images. This study tested whether relief of distress from competing VSSP tasks during imaginal exposure is at the cost of impaired desensitization . Design. This study examined repeated exposure to emotive memories using 18 unselected undergraduates and a within-subjects design with three exposure conditions (Eye Movement, Visual Noise, Exposure Alone) in random, counterbalanced order. Method. At baseline, participants recalled positive and negative experiences, and rated the vividness and emotiveness of each image. A different positive and negative recollection was then used for each condition. Vividness and emotiveness were rated after each of eight exposure trials. At a post-exposure session 1 week later, participants rated each image without any concurrent task. Results. Consistent with previous research, vividness and distress during imaging were lower during Eye Movements than in Exposure Alone, with passive visual interference giving intermediate results. A reduction in emotional responses from Baseline to Post was of similar size for the three conditions. Conclusion. Visuospatial tasks may offer a temporary response aid for imaginal exposure without affecting desensitization.

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Previous studies have reported that patients with schizophrenia demonstrate impaired performance during working memory (WM) tasks. The current study aimed to determine whether WM impairments in schizophrenia are accompanied by reduced slow wave (SW) activity during on-line maintenance of mnemonic information. Event-related potentials were obtained from patients with schizophrenia and well controls as they performed a visuospatial delayed response task. On 50% of trials, a distractor stimulus was introduced during the delay. Compared with controls, patients with schizophrenia produced less SW memory negativity, particularly over the right hemisphere, together with reduced frontal enhancement of SW memory negativity in response to distraction. The results indicate that patients with schizophrenia generate less maintenance phase neuronal activity during WM performance, especially under conditions of distraction.

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This combined PET and ERP study was designed to identify the brain regions activated in switching and divided attention between different features of a single object using matched sensory stimuli and motor response. The ERP data have previously been reported in this journal [64]. We now present the corresponding PET data. We identified partially overlapping neural networks with paradigms requiring the switching or dividing of attention between the elements of complex visual stimuli. Regions of activation were found in the prefrontal and temporal cortices and cerebellum. Each task resulted in different prefrontal cortical regions of activation lending support to the functional subspecialisation of the prefrontal and temporal cortices being based on the cognitive operations required rather than the stimuli themselves.

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Examined whether discrete working memory deficits underlie positive, negative and disorganised symptoms of schizophrenia. 52 outpatients (mean age 37.5 yrs) with schizophrenia were studied using items drawn from the Positive and Negative Syndrome Scale (PANSS). Linear regression and correlational analyses were conducted to examine whether symptom dimension scores were related to performance on several tests of working memory function. Severity of negative symptoms correlated with reduced production of words during a verbal fluency task, impaired ability to hold letter and number sequences on-line and manipulate them simultaneously, reduced performance during a dual task, and compromised visuospatial working memory under distraction-free conditions. Severity of disorganisation symptoms correlated with impaired visuospatial working memory under conditions of distraction, failure of inhibition during a verbal fluency task, perseverative responding on a test of set-shifting ability, and impaired ability to judge the veracity of simple declarative statements. The present study provides evidence that the positive, negative and disorganised symptom dimensions of the PANSS constitute independent clusters, associated with unique patterns of working memory impairment.

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It has been claimed that the symptoms of post-traumatic stress disorder (PTSD) can be ameliorated by eye-movement desensitization-reprocessing therapy (EMD-R), a procedure that involves the individual making saccadic eye-movements while imagining the traumatic event. We hypothesized that these eye-movements reduce the vividness of distressing images by disrupting the function of the visuospatial sketchpad (VSSP) of working memory, and that by doing so they reduce the intensity of the emotion associated with the image. This hypothesis was tested by asking non-PTSD participants to form images of neutral and negative pictures under dual task conditions. Their images were less vivid with concurrent eye-movements and with a concurrent spatial tapping task that did not involve eye-movements. In the first three experiments, these secondary tasks did not consistently affect participants' emotional responses to the images. However, Expt 4 used personal recollections as stimuli for the imagery task, and demonstrated a significant reduction in emotional response under the same dual task conditions. These results suggest that, if EMD-R works, it does so by reducing the vividness and emotiveness of traumatic images via the VSSP of working memory. Other visuospatial tasks may also be of therapeutic value.

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This report is the primary output of Project 4: Copyright and Intellectual Property, the aim of which was to produce a report considering how greater access to and use of government information could be achieved within the scope of the current copyright law. In our submission for Project 4, we undertook to address: •the policy rationales underlying copyright and how they apply in the context of materials owned, held and used by government; • the recommendations of the Copyright Law Review Committee (CLRC) in its 2005 report on Crown copyright; • the legislative and regulatory barriers to information sharing in key domains, including where legal impediments such as copyright have been relied upon (whether rightly or wrongly) to justify a refusal to provide access to government data; • copyright licensing models appropriate to government materials and examples of licensing initiatives in Australia and other relevant jurisdictions; and • issues specific to the galleries, libraries, archives and museums (“GLAM”) sector, including management of copyright in legacy materials and “orphan” works. In addressing these areas, we analysed the submissions received in response to the Government 2.0 Taskforce Issues Paper, consulted with members of the Task Force as well as several key stakeholders and considered the comments posted on the Task Force’s blog. This Project Report sets out our findings on the above issues. It puts forward recommendations for consideration by the Government 2.0 Task Force on steps that can be taken to ensure that copyright and intellectual property promote access to and use of government information.

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Tissue damage resulting from the extracellular production of HOCl (hypochlorous acid) by the MPO (myeloperoxidase)-hydrogen peroxide-chloride system of activated phagocytes is implicated as a key event in the progression of a number of human inflammatory diseases. Consequently, there is considerable interest in the development of therapeutically useful MPO inhibitors. Nitroxides are well established antioxidant compounds of low toxicity that can attenuate oxidative damage in animal models of inflammatory disease. They are believed to exert protective effects principally by acting as superoxide dismutase mimetics or radical scavengers. However, we show here that nitroxides can also potently inhibit MPO-mediated HOCl production, with the nitroxide 4-aminoTEMPO inhibiting HOCl production by MPO and by neutrophils with IC50 values of approx. 1 and 6 μM respectively. Structure–activity relationships were determined for a range of aliphatic and aromatic nitroxides, and inhibition of oxidative damage to two biologically-important protein targets (albumin and perlecan) are demonstrated. Inhibition was shown to involve one-electron oxidation of the nitroxides by the compound I form of MPO and accumulation of compound II. Haem destruction was also observed with some nitroxides. Inhibition of neutrophil HOCl production by nitroxides was antagonized by neutrophil-derived superoxide, with this attributed to superoxide-mediated reduction of compound II. This effect was marginal with 4-aminoTEMPO, probably due to the efficient superoxide dismutase-mimetic activity of this nitroxide. Overall, these data indicate that nitroxides have considerable promise as therapeutic agents for the inhibition of MPO-mediated damage in inflammatory diseases.

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This paper describes an initiative in the Faculty of Health at the Queensland University of Technology, Australia, where a short writing task was introduced to first year undergraduates in four courses including Public Health, Nursing, Social Work and Human Services, and Human Movement Studies. Over 1,000 students were involved in the trial. The task was assessed using an adaptation of the MASUS Procedure (Measuring the Academic Skills of University Students) (Webb & Bonanno, 1994). Feedback to the students including MASUS scores then enabled students to be directed to developmental workshops targeting their academic literacy needs. Students who achieved below the benchmark score were required to attend academic writing workshops in order to obtain the same summative 10% that was obtained by those who had achieved above the benchmark score. The trial was very informative, in terms of determining task appropriateness and timing, student feedback, student use of support, and student perceptions of the task and follow-up workshops. What we learned from the trial will be presented with a view to further refinement of this initiative.

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Purpose: To determine (a) the effect of different sunglass tint colorations on traffic signal detection and recognition for color normal and color deficient observers, and (b) the adequacy of coloration requirements in current sunglass standards. Methods: Twenty color-normals and 49 color-deficient males performed a tracking task while wearing sunglasses of different colorations (clear, gray, green, yellow-green, yellow-brown, red-brown). At random intervals, simulated traffic light signals were presented against a white background at 5° to the right or left and observers were instructed to identify signal color (red/yellow/green) by pressing a response button as quickly as possible; response times and response errors were recorded. Results: Signal color and sunglass tint had significant effects on response times and error rates (p < 0.05), with significant between-color group differences and interaction effects. Response times for color deficient people were considerably slower than color normals for both red and yellow signals for all sunglass tints, but for green signals they were only noticeably slower with the green and yellow-green lenses. For most of the color deficient groups, there were recognition errors for yellow signals combined with the yellow-green and green tints. In addition, deuteranopes had problems for red signals combined with red-brown and yellow-brown tints, and protanopes had problems for green signals combined with the green tint and for red signals combined with the red-brown tint. Conclusions: Many sunglass tints currently permitted for drivers and riders cause a measurable decrement in the ability of color deficient observers to detect and recognize traffic signals. In general, combinations of signals and sunglasses of similar colors are of particular concern. This is prima facie evidence of a risk in the use of these tints for driving and cautions against the relaxation of coloration limits in sunglasses beyond those represented in the study.

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This practice-led research project examines some of the factors and issues facing artists working in the public domain who wish to engage with the community as audience. Using the methodology of action research, the three major creative projects in this study use art as a socio-political tool with the aim of providing an effective vehicle for broadening awareness, understanding forms of social protest and increasing tolerance for diversity. The three projects: Floodline November 7, 2004, Look in, Look out, and The Urban Terrorist Project, dealt with issues of marginalisation of communities, audiences and graffiti artists respectively. The artist/researcher is outlined as both creator and collaborator in the work. Processes included ephemeral elements, such as temporary installation and performance, as well as interactive elements that encouraged direct audience involvement as part of the work. In addition to the roles of creator and collaborator, both of which included audience as well as artist, the presence of an outside entity was evident. Whether local, legal authorities or prevailing attitudes, outside entities had an unavoidable impact on the processes and outcomes of the work. Each project elicited a range of responses from their respective audiences; however, the overarching concept of reciprocity was seen to be the crucial factor in conception, artistic methods and outcomes.

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The use of animal sera for the culture of therapeutically important cells impedes the clinical use of the cells. We sought to characterize the functional response of human mesenchymal stem cells (hMSCs) to specific proteins known to exist in bone tissue with a view to eliminating the requirement of animal sera. Insulin-like growth factor-I (IGF-I), via IGF binding protein-3 or -5 (IGFBP-3 or -5) and transforming growth factor-beta 1 (TGF-beta(1)) are known to associate with the extracellular matrix (ECM) protein vitronectin (VN) and elicit functional responses in a range of cell types in vitro. We found that specific combinations of VN, IGFBP-3 or -5, and IGF-I or TGF-beta(1) could stimulate initial functional responses in hMSCs and that IGF-I or TGF-beta(1) induced hMSC aggregation, but VN concentration modulated this effect. We speculated that the aggregation effect may be due to endogenous protease activity, although we found that neither IGF-I nor TGF-beta(1) affected the functional expression of matrix metalloprotease-2 or -9, two common proteases expressed by hMSCs. In summary, combinations of the ECM and growth factors described herein may form the basis of defined cell culture media supplements, although the effect of endogenous protease expression on the function of such proteins requires investigation.