959 resultados para contextual rationality


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Evidence that lesions of the basolateral amygdala complex (BLC) impair memory for fear conditioning in rats, measured by lack of “freezing” behavior in the presence of cues previously paired with footshocks, has suggested that the BLC may be a critical locus for the memory of fear conditioning. However, evidence that BLC lesions may impair unlearned as well as conditioned freezing makes it difficult to interpret the findings of studies assessing conditioned fear with freezing. The present study investigated whether such lesions prevent the expression of several measures of memory for contextual fear conditioning in addition to freezing. On day 1, rats with sham lesions or BLC lesions explored a Y maze. The BLC-lesioned rats (BLC rats) displayed a greater exploratory activity. On day 2, each of the rats was placed in the “shock” arm of the maze, and all of the sham and half of the BLC rats received footshocks. A 24-hr retention test assessed the freezing, time spent per arm, entries per arm, and initial entry into the shock arm. As previously reported, shocked BLC rats displayed little freezing. However, the other measures indicated that the shocked BLC rats remembered the fear conditioning. They entered less readily and less often and spent less time in the shock arm than did the control nonshocked BLC rats. Compared with the sham rats, the shocked BLC rats entered more quickly and more often and spent more time in the shock arm. These findings indicate that an intact BLC is not essential for the formation and expression of long-term cognitive/explicit memory of contextual fear conditioning.

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CCAAT/enhancer binding protein δ (C/EBPδ) is a transcriptional regulator implicated in the hepatic acute phase response and in adipogenic and myeloid cell differentiation. We found that C/EBPδ is widely expressed in the peripheral and central nervous systems, including neurons of the hippocampal formation, indicating a role in neural functions. To examine the role of C/EBPδ in vivo, we generated mice with a targeted deletion of the C/EBPδ gene. This mutation does not interfere with normal embryonic and postnatal development. Performance in a battery of behavioral tests indicates that basic neurological functions are normal. Furthermore, performance in a Morris water maze task suggests that C/EBPδ mutant mice have normal spatial learning. However, in the contextual and auditory-cue-conditioned fear task, C/EBPδ null mice displayed significantly more conditioned freezing to the test context than did wild-type controls, but equivalent conditioning to the auditory cue. These data demonstrate a selectively enhanced contextual fear response in mice carrying a targeted genomic mutation and implicate C/EBPδ in the regulation of a specific type of learning and memory.

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Action selection and organization are very complex processes that need to exploit contextual information and the retrieval of previously memorized information, as well as the integration of these different types of data. On the basis of anatomical connection with premotor and parietal areas involved in action goal coding, and on the data about the literature it seems appropriate to suppose that one of the most candidate involved in the selection of neuronal pools for the selection and organization of intentional actions is the prefrontal cortex. We recorded single ventrolateral prefrontal (VLPF) neurons activity while monkeys performed simple and complex manipulative actions aimed at distinct final goals, by employing a modified and more strictly controlled version of the grasp-to-eat(a food pellet)/grasp-to-place(an object) paradigm used in previous studies on parietal (Fogassi et al., 2005) and premotor neurons (Bonini et al., 2010). With this task we have been able both to evaluate the processing and integration of distinct (visual and auditory) contextual sequentially presented information in order to select the forthcoming action to perform and to examine the possible presence of goal-related activity in this portion of cortex. Moreover, we performed an observation task to clarify the possible contribution of VLPF neurons to the understanding of others’ goal-directed actions. Simple Visuo Motor Task (sVMT). We found four main types of neurons: unimodal sensory-driven, motor-related, unimodal sensory-and-motor, and multisensory neurons. We found a substantial number of VLPF neurons showing both a motor-related discharge and a visual presentation response (sensory-and-motor neurons), with remarkable visuo-motor congruence for the preferred target. Interestingly the discharge of multisensory neurons reflected a behavioural decision independently from the sensory modality of the stimulus allowing the monkey to make it: some encoded a decision to act/refraining from acting (the majority), while others specified one among the four behavioural alternatives. Complex Visuo Motor Task (cVMT). The cVMT was similar to the sVMT, but included a further grasping motor act (grasping a lid in order to remove it, before grasping the target) and was run in two modalities: randomized and in blocks. Substantially, motor-related and sensory-and-motor neurons tested in the cVMTrandomized were activated already during the first grasping motor act, but the selectivity for one of the two graspable targets emerged only during the execution of the second grasping. In contrast, when the cVMT was run in block, almost all these neurons not only discharged during the first grasping motor act, but also displayed the same target selectivity showed in correspondence of the hand contact with the target. Observation Task (OT). A great part of the neurons active during the OT showed a firing rate modulation in correspondence with the action performed by the experimenter. Among them, we found neurons significantly activated during the observation of the experimenter’s action (action observation-related neurons) and neurons responding not only to the action observation, but also to the presented cue stimuli (sensory-and-action observation-related neurons. Among the neurons of the first set, almost the half displayed a target selectivity, with a not clear difference between the two presented targets; Concerning to the second neuronal set, sensory-and-action related neurons, we found a low target selectivity and a not strictly congruence between the selectivity exhibited in the visual response and in the action observation.

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Given the historical rates of combat post-traumatic stress disorder (PTSD), one can expect 30% of soldiers returning from current military conflicts to suffer from PTSD. For these individuals, various cognitive behavioral therapies (CBT) are the most commonly employed treatments. Unfortunately, however, symptom relapse can be expected with the various CBT approaches, as traumatic memories remain. Soldiers are imbued with a militarized identity, and the identity loss experienced by those soldiers who suffer from PTSD is particularly painful for this population, as the militarized identity effectively disavows personal suffering. For this reason, many combat veterans diagnosed with post-traumatic stress disorder experience undue, prolonged suffering as they struggle to make sense of the different person they fear they have become. This paper contrasts certain versions of Western philosophy, which view the self as a fixed and reified entity with certain versions of Eastern philosophy, which view the self as more contextual and fluid, in order to illuminate the value of employing third wave behavioral treatments, specifically Acceptance and Commitment Therapy (ACT), to treat the identity loss experienced by military veterans with PTSD. ACT echoes the Buddhist principle that attachment to verbally-constructed conceptual notions of self contribute to undue suffering, and that more vital living can be achieved by assuming a more contextual and experiential perspective on identity. Research and anecdotal accounts are cited to illustrate why treatment for identity loss associated with combat PTSD should be less focused on reconstructing a historically substance-oriented self and more focused on an epistemological reorientation to a deconstructed, contextual self.

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In this paper, we present a novel coarse-to-fine visual localization approach: contextual visual localization. This approach relies on three elements: (i) a minimal-complexity classifier for performing fast coarse localization (submap classification); (ii) an optimized saliency detector which exploits the visual statistics of the submap; and (iii) a fast view-matching algorithm which filters initial matchings with a structural criterion. The latter algorithm yields fine localization. Our experiments show that these elements have been successfully integrated for solving the global localization problem. Context, that is, the awareness of being in a particular submap, is defined by a supervised classifier tuned for a minimal set of features. Visual context is exploited both for tuning (optimizing) the saliency detection process, and to select potential matching views in the visual database, close enough to the query view.

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This study evaluates the technical efficiency of the learning-teaching process in higher education using a three-stage procedure that offers advances in comparison to previous studies and improves the quality of the results. First, it utilizes a multiple stage Data Envelopment Analysis (DEA) with contextual variables. Second, the levels of super efficiency are calculated in order to prioritize the efficiency units. And finally, through sensitivity analysis, the contribution of each key performance indicator (KPI) is established with respect to the efficiency levels without omission of variables. The analytical data was collected from a survey completed by 633 tourism students during the 2011/12, 2012/13 and 2013/14 academic course years. The results suggest that level of satisfaction with the course, diversity of materials and satisfaction with the teacher were the most important factors affecting teaching performance. Furthermore, the effect of the contextual variables was found to be significant.

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Because millions of youth are involved in sport, the sport context is important to consider in advancing the growth experiences of young people (Cˆot´e et al., 2007; Fraser-Thomas et al., 2005). Furthermore, research in developmental psychology has highlighted the value of structured programs, including sport, in helping to promote positive youth development (Fredricks & Eccles, 2006). Youth sport involvement has been linked to high levels of enjoyment (Scanlan et al., 1989), however, negative outcomes, such as burnout, have also been reported (Gould et al., 1996). In the present study, the Developmental Assets Profile (Search Institute, 2004) was used to explore personal (internal assets) and contextual (external assets) outcomes associated with youth sport. Results suggest that three particular assets (positive identity, empowerment, and support) are important to focus on in youth sport programs to decrease burnout symptoms and enhance enjoyment. Path analyses were also conducted to test a proposed model and exploratory results confirmed links of particular assets to sport outcomes. The results are discussed in terms of integration with Bronfenbrenner’s ecological theory (1999) and recommendations are suggested for sport programmers to consider to develop these assets within youth sport.

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Research on emotion inferences has shown that readers include a representation of the main character's emotional state in their mental representations of the text. We examined the specificity of emotion representations as a function of the emotion content of short narratives, in terms of the quantity and quality of emotion components included in the narratives, based on the GRID instrument (Fontaine et al., 2013). In a self-paced reading task, target sentences that only moderately matched the emotional context were read faster than target sentences that strongly matched the emotional context of the narratives. In a “makes sense” judgment task, we showed that this result was not driven by a mapping difficulty and, in a memory task, we provided some evidence that these effects reflected integration processes. We suggest that readers can integrate specific emotions into their mental representations, but only if provided with the appropriate emotional contextual support.

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Thèse réalisée en cotutelle entre l'Université de Montréal et l'Université Pierre et Marie Curie, Paris 06, Sorbonne Universités.

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Thesis (Ph. D.)--University of California, 1912.

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Two studies in the context of English-French relations in Québec suggest that individuals who strongly identify with a group derive the individual-level costs and benefits that drive expectancy-value processes (rational decision-making) from group-level costs and benefits. In Study 1, high identifiers linked group- and individual-level outcomes of conflict choices whereas low identifiers did not. Group-level expectancy-value processes, in Study 2, mediated the relationship between social identity and perceptions that collective action benefits the individual actor and between social identity and intentions to act. These findings suggest the rational underpinnings of identity-driven political behavior, a relationship sometimes obscured in intergroup theory that focuses on cognitive processes of self-stereotyping. But the results also challenge the view that individuals' cost-benefit analyses are independent of identity processes. The findings suggest the importance of modeling the relationship of group and individual levels of expectancy-value processes as both hierarchical and contingent on social identity processes

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Very few empirically validated interventions for improving metacognitive skills (i.e., self-awareness and self-regulation) and functional outcomes have been reported. This single-case experimental study presents JM, a 36-year-old man with a very severe traumatic brain injury (TBI) who demonstrated long-term awareness deficits. Treatment at four years post-injury involved a metacognitive contextual intervention based on a conceptualization of neuro-cognitive, psychological, and socio-environmental factors contributing to his awareness deficits. The 16-week intervention targeted error awareness and self-correction in two real life settings: (a) cooking at home: and (b) volunteer work. Outcome measures included behavioral observation of error behavior and standardized awareness measures. Relative to baseline performance in the cooking setting, JM demonstrated a 44% reduction in error frequency and increased self-correction. Although no spontaneous generalization was evident in the volunteer work setting, specific training in this environment led to a 39% decrease in errors. JM later gained paid employment and received brief metacognitive training in his work environment. JM's global self-knowledge of deficits assessed by self-report was unchanged after the program. Overall, the study provides preliminary support for a metacognitive contextual approach to improve error awareness and functional Outcome in real life settings.