15 resultados para Task shifting
em Duke University
Resumo:
Background: The burden of mental health is increased in humanitarian settings, and needs to be addressed in emergency situations. The World Health Organization has recently released the mental health Global Action Programme Humanitarian Intervention Guide (mhGAP-HIG) in order to scale up mental health service delivery in humanitarian settings through task-shifting. This study aims to evaluate, contextualize and identify possible barriers and challenges to mhGAP-HIG manual content, training and implementation in post-earthquake Nepal.
Methods: This qualitative study was conducted in Kathmandu, Nepal. Key informant interviews were conducted with fourteen psychiatrists involved in a mhGAP-HIG Training of Trainers and Supervisors (ToTS) in order to assess the mhGAP-HIG, ToTS training, and the potential challenges and barriers to mhGAP-HIG implementation. Themes identified by informants were supplemented by process notes taken by the researcher during observed training sessions and meetings.
Results: Key themes emerging from key informant interviews include the need to take three factors into account in manual contextualization: culture, health systems and the humanitarian setting. This includes translation of the manual into the local language, adding or expanding upon conditions prevalent in Nepal, and more consideration to improving feasibility of manual use by non-specialists.
Conclusion: The mhGAP-HIG must be tailored to specific humanitarian settings for effective implementation. This study shows the importance of conducting a manual contextualization workshop prior to training in order to maximize the feasibility and success in training health care workers in mhGAP.
Resumo:
This dissertation examines how the crisis of World War I impacted imperial policy and popular claims-making in the British Caribbean. Between 1915 and 1918, tens of thousands of men from the British Caribbean volunteered to fight in World War I and nearly 16,000 men, hailing from every British colony in the region, served in the newly formed British West Indies Regiment (BWIR). Rousing appeals to imperial patriotism and manly duty during the wartime recruitment campaigns and postwar commemoration movement linked the British Empire, civilization, and Christianity while simultaneously promoting new roles for women vis-à-vis the colonial state. In Jamaica and Trinidad and Tobago, the two colonies that contributed over seventy-five percent of the British Caribbean troops, discussions about the meaning of the war for black, coloured, white, East Indian, and Chinese residents sparked heated debates about the relationship among race, gender, and imperial loyalty.
To explore these debates, this dissertation foregrounds the social, cultural, and political practices of BWIR soldiers, tracing their engagements with colonial authorities, military officials, and West Indian civilians throughout the war years. It begins by reassessing the origins of the BWIR, and then analyzes the regional campaign to recruit West Indian men for military service. Travelling with newly enlisted volunteers across the Atlantic, this study then chronicles soldiers' multi-sited campaign for equal status, pay, and standing in the British imperial armed forces. It closes by offering new perspectives on the dramatic postwar protests by BWIR soldiers in Italy in 1918 and British Honduras and Trinidad in 1919, and reflects on the trajectory of veterans' activism in the postwar era.
This study argues that the racism and discrimination soldiers experienced overseas fueled heightened claims-making in the postwar era. In the aftermath of the war, veterans mobilized collectively to garner financial support and social recognition from colonial officials. Rather than withdrawing their allegiance from the empire, ex-servicemen and civilians invoked notions of mutual obligation to argue that British officials owed a debt to West Indians for their wartime sacrifices. This study reveals the continued salience of imperial patriotism, even as veterans and their civilian allies invoked nested local, regional, and diasporic loyalties as well. In doing so, it contributes to the literature on the origins of patriotism in the colonial Caribbean, while providing a historical case study for contemporary debates about "hegemonic dissolution" and popular mobilization in the region.
This dissertation draws upon a wide range of written and visual sources, including archival materials, war recruitment posters, newspapers, oral histories, photographs, and memoirs. In addition to Colonial Office records and military files, it incorporates previously untapped letters and petitions from the Jamaica Archives, National Archives of Trinidad and Tobago, Barbados Department of Archives, and US National Archives.
Resumo:
Emotional and attentional functions are known to be distributed along ventral and dorsal networks in the brain, respectively. However, the interactions between these systems remain to be specified. The present study used event-related functional magnetic resonance imaging (fMRI) to investigate how attentional focus can modulate the neural activity elicited by scenes that vary in emotional content. In a visual oddball task, aversive and neutral scenes were presented intermittently among circles and squares. The squares were frequent standard events, whereas the other novel stimulus categories occurred rarely. One experimental group [N=10] was instructed to count the circles, whereas another group [N=12] counted the emotional scenes. A main effect of emotion was found in the amygdala (AMG) and ventral frontotemporal cortices. In these regions, activation was significantly greater for emotional than neutral stimuli but was invariant to attentional focus. A main effect of attentional focus was found in dorsal frontoparietal cortices, whose activity signaled task-relevant target events irrespective of emotional content. The only brain region that was sensitive to both emotion and attentional focus was the anterior cingulate gyrus (ACG). When circles were task-relevant, the ACG responded equally to circle targets and distracting emotional scenes. The ACG response to emotional scenes increased when they were task-relevant, and the response to circles concomitantly decreased. These findings support and extend prominent network theories of emotion-attention interactions that highlight the integrative role played by the anterior cingulate.
Resumo:
A framework for adaptive and non-adaptive statistical compressive sensing is developed, where a statistical model replaces the standard sparsity model of classical compressive sensing. We propose within this framework optimal task-specific sensing protocols specifically and jointly designed for classification and reconstruction. A two-step adaptive sensing paradigm is developed, where online sensing is applied to detect the signal class in the first step, followed by a reconstruction step adapted to the detected class and the observed samples. The approach is based on information theory, here tailored for Gaussian mixture models (GMMs), where an information-theoretic objective relationship between the sensed signals and a representation of the specific task of interest is maximized. Experimental results using synthetic signals, Landsat satellite attributes, and natural images of different sizes and with different noise levels show the improvements achieved using the proposed framework when compared to more standard sensing protocols. The underlying formulation can be applied beyond GMMs, at the price of higher mathematical and computational complexity. © 1991-2012 IEEE.
Resumo:
Geospatial modeling is one of the most powerful tools available to conservation biologists for estimating current species ranges of Earth's biodiversity. Now, with the advantage of predictive climate models, these methods can be deployed for understanding future impacts on threatened biota. Here, we employ predictive modeling under a conservative estimate of future climate change to examine impacts on the future abundance and geographic distributions of Malagasy lemurs. Using distribution data from the primary literature, we employed ensemble species distribution models and geospatial analyses to predict future changes in species distributions. Current species distribution models (SDMs) were created within the BIOMOD2 framework that capitalizes on ten widely used modeling techniques. Future and current SDMs were then subtracted from each other, and areas of contraction, expansion, and stability were calculated. Model overprediction is a common issue associated Malagasy taxa. Accordingly, we introduce novel methods for incorporating biological data on dispersal potential to better inform the selection of pseudo-absence points. This study predicts that 60% of the 57 species examined will experience a considerable range of reductions in the next seventy years entirely due to future climate change. Of these species, range sizes are predicted to decrease by an average of 59.6%. Nine lemur species (16%) are predicted to expand their ranges, and 13 species (22.8%) distribution sizes were predicted to be stable through time. Species ranges will experience severe shifts, typically contractions, and for the majority of lemur species, geographic distributions will be considerably altered. We identify three areas in dire need of protection, concluding that strategically managed forest corridors must be a key component of lemur and other biodiversity conservation strategies. This recommendation is all the more urgent given that the results presented here do not take into account patterns of ongoing habitat destruction relating to human activities.
Resumo:
Older adults tend to retrieve autobiographical information that is overly general (i.e., not restricted to a single event, termed the overgenerality effect) relative to young adults' specific memories. A vast majority of studies that have reported overgenerality effects explicitly instruct participants to retrieve specific memories, thereby requiring participants to maintain task goals, inhibit inappropriate responses, and control their memory search. Since these processes are impaired in healthy ageing, it is important to determine whether such task instructions influence the magnitude of the overgenerality effect in older adults. In the current study participants retrieved autobiographical memories during presentation of musical clips. Task instructions were manipulated to separate age-related differences in the specificity of underlying memory representations from age-related differences in following task instructions. Whereas young adults modulated memory specificity based on task demands, older adults did not. These findings suggest that reported rates of overgenerality in older adults' memories might include age-related differences in memory representation, as well as differences in task compliance. Such findings provide a better understanding of the underlying cognitive mechanisms involved in age-related changes in autobiographical memory and may also be valuable for future research examining effects of overgeneral memory on general well-being. © 2013 Taylor & Francis.
Resumo:
Older adults tend to retrieve autobiographical information that is overly general (i.e., not restricted to a single event, termed the overgenerality effect) relative to young adults' specific memories. A vast majority of studies that have reported overgenerality effects explicitly instruct participants to retrieve specific memories, thereby requiring participants to maintain task goals, inhibit inappropriate responses, and control their memory search. Since these processes are impaired in healthy ageing, it is important to determine whether such task instructions influence the magnitude of the overgenerality effect in older adults. In the current study participants retrieved autobiographical memories during presentation of musical clips. Task instructions were manipulated to separate age-related differences in the specificity of underlying memory representations from age-related differences in following task instructions. Whereas young adults modulated memory specificity based on task demands, older adults did not. These findings suggest that reported rates of overgenerality in older adults' memories might include age-related differences in memory representation, as well as differences in task compliance. Such findings provide a better understanding of the underlying cognitive mechanisms involved in age-related changes in autobiographical memory and may also be valuable for future research examining effects of overgeneral memory on general well-being.
Resumo:
Four experiments examined participants' ability to produce surface characteristics of sentences using an on-line story reading task. Participants read a series of stories in which either all, or the majority of sentences were written in the same "style," or surface form. Twice per story, participants were asked to fill in a blank consistent with the story. For sentences that contained three stylistic regularities, participants imitated either all three characteristics (Experiment 2) or two of the three characteristics (Experiment 1), depending on the proportion of in-style sentences. Participants demonstrated a recognition bias for the read style in an unannounced recognition task. When participants read stories in which the two styles were the dative/double object alternation, participants demonstrated a syntactic priming effect in the cloze task, but no consistent recognition bias in a later recognition test (Experiments 3 and 4).
Resumo:
Although it is known that brain regions in one hemisphere may interact very closely with their corresponding contralateral regions (collaboration) or operate relatively independent of them (segregation), the specific brain regions (where) and conditions (how) associated with collaboration or segregation are largely unknown. We investigated these issues using a split field-matching task in which participants matched the meaning of words or the visual features of faces presented to the same (unilateral) or to different (bilateral) visual fields. Matching difficulty was manipulated by varying the semantic similarity of words or the visual similarity of faces. We assessed the white matter using the fractional anisotropy (FA) measure provided by diffusion tensor imaging (DTI) and cross-hemispheric communication in terms of fMRI-based connectivity between homotopic pairs of cortical regions. For both perceptual and semantic matching, bilateral trials became faster than unilateral trials as difficulty increased (bilateral processing advantage, BPA). The study yielded three novel findings. First, whereas FA in anterior corpus callosum (genu) correlated with word-matching BPA, FA in posterior corpus callosum (splenium-occipital) correlated with face-matching BPA. Second, as matching difficulty intensified, cross-hemispheric functional connectivity (CFC) increased in domain-general frontopolar cortex (for both word and face matching) but decreased in domain-specific ventral temporal lobe regions (temporal pole for word matching and fusiform gyrus for face matching). Last, a mediation analysis linking DTI and fMRI data showed that CFC mediated the effect of callosal FA on BPA. These findings clarify the mechanisms by which the hemispheres interact to perform complex cognitive tasks.
Resumo:
This study investigated whether rhesus monkeys show evidence of metacognition in a reduced, visual oculomotor task that is particularly suitable for use in fMRI and electrophysiology. The 2-stage task involved punctate visual stimulation and saccadic eye movement responses. In each trial, monkeys made a decision and then made a bet. To earn maximum reward, they had to monitor their decision and use that information to bet advantageously. Two monkeys learned to base their bets on their decisions within a few weeks. We implemented an operational definition of metacognitive behavior that relied on trial-by-trial analyses and signal detection theory. Both monkeys exhibited metacognition according to these quantitative criteria. Neither external visual cues nor potential reaction time cues explained the betting behavior; the animals seemed to rely exclusively on internal traces of their decisions. We documented the learning process of one monkey. During a 10-session transition phase, betting switched from random to a decision-based strategy. The results reinforce previous findings of metacognitive ability in monkeys and may facilitate the neurophysiological investigation of metacognitive functions.
Resumo:
Inhibitory motor control is a core function of cognitive control. Evidence from diverse experimental approaches has linked this function to a mostly right-lateralized network of cortical and subcortical areas, wherein a signal from the frontal cortex to the basal ganglia is believed to trigger motor-response cancellation. Recently, however, it has been recognized that in the context of typical motor-control paradigms those processes related to actual response inhibition and those related to the attentional processing of the relevant stimuli are highly interrelated and thus difficult to distinguish. Here, we used fMRI and a modified Stop-signal task to specifically examine the role of perceptual and attentional processes triggered by the different stimuli in such tasks, thus seeking to further distinguish other cognitive processes that may precede or otherwise accompany the implementation of response inhibition. In order to establish which brain areas respond to sensory stimulation differences by rare Stop-stimuli, as well as to the associated attentional capture that these may trigger irrespective of their task-relevance, we compared brain activity evoked by Stop-trials to that evoked by Go-trials in task blocks where Stop-stimuli were to be ignored. In addition, region-of-interest analyses comparing the responses to these task-irrelevant Stop-trials, with those to typical relevant Stop-trials, identified separable activity profiles as a function of the task-relevance of the Stop-signal. While occipital areas were mostly blind to the task-relevance of Stop-stimuli, activity in temporo-parietal areas dissociated between task-irrelevant and task-relevant ones. Activity profiles in frontal areas, in turn, were activated mainly by task-relevant Stop-trials, presumably reflecting a combination of triggered top-down attentional influences and inhibitory motor-control processes.
Resumo:
This research validates a computerized dietary selection task (Food-Linked Virtual Response or FLVR) for use in studies of food consumption. In two studies, FLVR task responses were compared with measures of health consciousness, mood, body mass index, personality, cognitive restraint toward food, and actual food selections from a buffet table. The FLVR task was associated with variables which typically predict healthy decision-making and was unrelated to mood or body mass index. Furthermore, the FLVR task predicted participants' unhealthy selections from the buffet, but not overall amount of food. The FLVR task is an inexpensive, valid, and easily administered option for assessing momentary dietary decisions.
Resumo:
In most diffusion tensor imaging (DTI) studies, images are acquired with either a partial-Fourier or a parallel partial-Fourier echo-planar imaging (EPI) sequence, in order to shorten the echo time and increase the signal-to-noise ratio (SNR). However, eddy currents induced by the diffusion-sensitizing gradients can often lead to a shift of the echo in k-space, resulting in three distinct types of artifacts in partial-Fourier DTI. Here, we present an improved DTI acquisition and reconstruction scheme, capable of generating high-quality and high-SNR DTI data without eddy current-induced artifacts. This new scheme consists of three components, respectively, addressing the three distinct types of artifacts. First, a k-space energy-anchored DTI sequence is designed to recover eddy current-induced signal loss (i.e., Type 1 artifact). Second, a multischeme partial-Fourier reconstruction is used to eliminate artificial signal elevation (i.e., Type 2 artifact) associated with the conventional partial-Fourier reconstruction. Third, a signal intensity correction is applied to remove artificial signal modulations due to eddy current-induced erroneous T2(∗) -weighting (i.e., Type 3 artifact). These systematic improvements will greatly increase the consistency and accuracy of DTI measurements, expanding the utility of DTI in translational applications where quantitative robustness is much needed.
Resumo:
Both stimulus and response conflict can disrupt behavior by slowing response times and decreasing accuracy. Although several neural activations have been associated with conflict processing, it is unclear how specific any of these are to the type of stimulus conflict or the amount of response conflict. Here, we recorded electrical brain activity, while manipulating the type of stimulus conflict in the task (spatial [Flanker] versus semantic [Stroop]) and the amount of response conflict (two versus four response choices). Behaviorally, responses were slower to incongruent versus congruent stimuli across all task and response types, along with overall slowing for higher response-mapping complexity. The earliest incongruency-related neural effect was a short-duration frontally-distributed negativity at ~200 ms that was only present in the Flanker spatial-conflict task. At longer latencies, the classic fronto-central incongruency-related negativity 'N(inc)' was observed for all conditions, but was larger and ~100 ms longer in duration with more response options. Further, the onset of the motor-related lateralized readiness potential (LRP) was earlier for the two vs. four response sets, indicating that smaller response sets enabled faster motor-response preparation. The late positive complex (LPC) was present in all conditions except the two-response Stroop task, suggesting this late conflict-related activity is not specifically related to task type or response-mapping complexity. Importantly, across tasks and conditions, the LRP onset at or before the conflict-related N(inc), indicating that motor preparation is a rapid, automatic process that interacts with the conflict-detection processes after it has begun. Together, these data highlight how different conflict-related processes operate in parallel and depend on both the cognitive demands of the task and the number of response options.
Resumo:
Recent memories are generally recalled from a first-person perspective whereas older memories are often recalled from a third-person perspective. We investigated how repeated retrieval affects the availability of visual information, and whether it could explain the observed shift in perspective with time. In Experiment 1, participants performed mini-events and nominated memories of recent autobiographical events in response to cue words. Next, they described their memory for each event and rated its phenomenological characteristics. Over the following three weeks, they repeatedly retrieved half of the mini-event and cue-word memories. No instructions were given about how to retrieve the memories. In Experiment 2, participants were asked to adopt either a first- or third-person perspective during retrieval. One month later, participants retrieved all of the memories and again provided phenomenology ratings. When first-person visual details from the event were repeatedly retrieved, this information was retained better and the shift in perspective was slowed.