996 resultados para Attention Perception
Resumo:
Disorders of language, spatial perception, attention, memory, calculation and praxis are a frequent consequence of acquired brain damage [in particular, stroke and traumatic brain injury (TBI)] and a major determinant of disability. The rehabilitation of aphasia and, more recently, of other cognitive disorders is an important area of neurological rehabilitation. We report here a review of the available evidence about effectiveness of cognitive rehabilitation. Given the limited number and generally low quality of randomized clinical trials (RCTs) in this area of therapeutic intervention, the Task Force considered, besides the available Cochrane reviews, evidence of lower classes which was critically analysed until a consensus was reached. In particular, we considered evidence from small group or single cases studies including an appropriate statistical evaluation of effect sizes. The general conclusion is that there is evidence to award a grade A, B or C recommendation to some forms of cognitive rehabilitation in patients with neuropsychological deficits in the post-acute stage after a focal brain lesion (stroke, TBI). These include aphasia therapy, rehabilitation of unilateral spatial neglect (ULN), attentional training in the post-acute stage after TBI, the use of electronic memory aids in memory disorders, and the treatment of apraxia with compensatory strategies. There is clearly a need for adequately designed studies in this area, which should take into account specific problems such as patient heterogeneity and treatment standardization.
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Background Accurate automatic segmentation of the caudate nucleus in magnetic resonance images (MRI) of the brain is of great interest in the analysis of developmental disorders. Segmentation methods based on a single atlas or on multiple atlases have been shown to suitably localize caudate structure. However, the atlas prior information may not represent the structure of interest correctly. It may therefore be useful to introduce a more flexible technique for accurate segmentations. Method We present Cau-dateCut: a new fully-automatic method of segmenting the caudate nucleus in MRI. CaudateCut combines an atlas-based segmentation strategy with the Graph Cut energy-minimization framework. We adapt the Graph Cut model to make it suitable for segmenting small, low-contrast structures, such as the caudate nucleus, by defining new energy function data and boundary potentials. In particular, we exploit information concerning the intensity and geometry, and we add supervised energies based on contextual brain structures. Furthermore, we reinforce boundary detection using a new multi-scale edgeness measure. Results We apply the novel CaudateCut method to the segmentation of the caudate nucleus to a new set of 39 pediatric attention-deficit/hyperactivity disorder (ADHD) patients and 40 control children, as well as to a public database of 18 subjects. We evaluate the quality of the segmentation using several volumetric and voxel by voxel measures. Our results show improved performance in terms of segmentation compared to state-of-the-art approaches, obtaining a mean overlap of 80.75%. Moreover, we present a quantitative volumetric analysis of caudate abnormalities in pediatric ADHD, the results of which show strong correlation with expert manual analysis. Conclusion CaudateCut generates segmentation results that are comparable to gold-standard segmentations and which are reliable in the analysis of differentiating neuroanatomical abnormalities between healthy controls and pediatric ADHD.
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Evaluating other individuals with respect to personality characteristics plays a crucial role in human relations and it is the focus of attention for research in diverse fields such as psychology and interactive computer systems. In psychology, face perception has been recognized as a key component of this evaluation system. Multiple studies suggest that observers use face information to infer personality characteristics. Interactive computer systems are trying to take advantage of these findings and apply them to increase the natural aspect of interaction and to improve the performance of interactive computer systems. Here, we experimentally test whether the automatic prediction of facial trait judgments (e.g. dominance) can be made by using the full appearance information of the face and whether a reduced representation of its structure is sufficient. We evaluate two separate approaches: a holistic representation model using the facial appearance information and a structural model constructed from the relations among facial salient points. State of the art machine learning methods are applied to a) derive a facial trait judgment model from training data and b) predict a facial trait value for any face. Furthermore, we address the issue of whether there are specific structural relations among facial points that predict perception of facial traits. Experimental results over a set of labeled data (9 different trait evaluations) and classification rules (4 rules) suggest that a) prediction of perception of facial traits is learnable by both holistic and structural approaches; b) the most reliable prediction of facial trait judgments is obtained by certain type of holistic descriptions of the face appearance; and c) for some traits such as attractiveness and extroversion, there are relationships between specific structural features and social perceptions.
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PRINCIPLE: Healthcare professionals' (HCPs') perception of risk associated with drug use in pregnancy may have an impact on the pharmacological treatment of some women. The aim of this study was to examine this risk perception in a sample of Swiss HCPs with a special focus on their knowledge and use of available specialised information sources. METHOD: An online, French and German, questionnaire was e-mailed to 7,136 members of four Swiss professional societies (gynaecologists, paediatricians, midwives and pharmacists). The questionnaire was designed (a) to collect demographic characteristics, (b) to evaluate the frequency of use of several specialised sources of information on drugs in pregnancy in their daily practice, and (c) to examine the perception of risk associated with drug use during pregnancy. RESULTS: A total of 1,310 questionnaires were collected (response rate of 18.4%). More than 80% of the respondent HCPs use the Swiss Drug Reference Book (Compendium) to assess the risk associated with drugs during pregnancy and are not aware of available specialised information sources (books, websites or information centres). Despite some disparities between HPCs, the risk related to drug intake was overall highly misperceived. Blinded reading of three product monographs in the Compendium was associated with an overestimated perception of risk (e.g., after reading the "paracetamol" monograph, 38% of the participants stated they would probably not advise the use of this drug to a pregnant patient). CONCLUSION: Overall, an overestimation of the risk associated with drug use during pregnancy has been observed in our sample of HCPs, which might be related to the underuse of specialised information source among other factors. These findings evidenced the need for increased training for HCPs in order to optimise medication use during pregnancy. Further studies are needed to confirm these results and identify causes.
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Dans le domaine de la perception, l'apprentissage est contraint par la présence d'une architecture fonctionnelle constituée d'aires corticales distribuées et très spécialisées. Dans le domaine des troubles visuels d'origine cérébrale, l'apprentissage d'un patient hémi-anopsique ou agnosique sera limité par ses capacités perceptives résiduelles, mais un déficit de reconnaissance visuelle de nature apparemment perceptive, peut également être associé à une altération des représentations en mémoire à long terme. Des réseaux neuronaux distincts pour la reconnaissance - cortex temporal - et pour la localisation des sons - cortex pariétal - ont été décrits chez l'homme. L'étude de patients cérébro-lésés confirme le rôle des indices spatiaux dans un traitement auditif explicite du « where » et dans la discrimination implicite du « what ». Cette organisation, similaire à ce qui a été décrit dans la modalité visuelle, faciliterait les apprentissages perceptifs. Plus généralement, l'apprentissage implicite fonde une grande partie de nos connaissances sur le monde en nous rendant sensible, à notre insu, aux règles et régularités de notre environnement. Il serait impliqué dans le développement cognitif, la formation des réactions émotionnelles ou encore l'apprentissage par le jeune enfant de sa langue maternelle. Le caractère inconscient de cet apprentissage est confirmé par l'étude des temps de réaction sériels de patients amnésiques dans l'acquisition d'une grammaire artificielle. Son évaluation pourrait être déterminante dans la prise en charge ré-adaptative. [In the field of perception, learning is formed by a distributed functional architecture of very specialized cortical areas. For example, capacities of learning in patients with visual deficits - hemianopia or visual agnosia - from cerebral lesions are limited by perceptual abilities. Moreover a visual deficit in link with abnormal perception may be associated with an alteration of representations in long term (semantic) memory. Furthermore, perception and memory traces rely on parallel processing. This has been recently demonstrated for human audition. Activation studies in normal subjects and psychophysical investigations in patients with focal hemispheric lesions have shown that auditory information relevant to sound recognition and that relevant to sound localisation are processed in parallel, anatomically distinct cortical networks, often referred to as the "What" and "Where" processing streams. Parallel processing may appear counterintuitive from the point of view of a unified perception of the auditory world, but there are advantages, such as rapidity of processing within a single stream, its adaptability in perceptual learning or facility of multisensory interactions. More generally, implicit learning mechanisms are responsible for the non-conscious acquisition of a great part of our knowledge about the world, using our sensitivity to the rules and regularities structuring our environment. Implicit learning is involved in cognitive development, in the generation of emotional processing and in the acquisition of natural language. Preserved implicit learning abilities have been shown in amnesic patients with paradigms like serial reaction time and artificial grammar learning tasks, confirming that implicit learning mechanisms are not sustained by the cognitive processes and the brain structures that are damaged in amnesia. In a clinical perspective, the assessment of implicit learning abilities in amnesic patients could be critical for building adapted neuropsychological rehabilitation programs.]
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L'épreuve « factuelle » et physique de la brûlure grave des grands brûlés de la face fait l'objet d'une analyse sociologique systématique : alors qu'un accident peut, en quelques secondes, provoquer une véritable rupture biographique, l'acceptation du nouveau statut et la « reconstruction » d'un rapport à soi et aux autres prend beaucoup de temps. Les modalités de cette reconstruction et les tentatives pour retrouver une impossible « apparence normale » dans la vie publique sont ici analysées. Tout en étant attentive aux modalités de l'interaction, la présente étude relève d'une démarche sociologique compréhensive menée à partir d'observations et d'entretiens conduits avec ces personnes, amenant dans le giron de la sociologie une expérience éprouvanteencore peu connue, celle des grands brûlés de la face. Le registre discursif adossé à cette dernière vient compléter certaines représentations véhiculées par les médias, les fictions et qui influent sur la perception et la visibilité de ceux-ci. A l'aune du concept d'épreuve issu de la « sociologie pragmatique », le parcours du grand brûlé peut être examiné en prêtant une attention particulière au moment initial du parcours post¬brûlure : l'accident. La mise en récit de cette première épreuve est révélatrice des tentatives pour le grand brûlé de maintenir un lien entre un avant et un après l'accident. S'ensuit un continuum d'épreuves intervenant dès le moment où les grands brûlés se présentent physiquement face à autrui dans l'espace public suscitant des réactions de gêne et de malaise. Dans le prolongement des travaux d'Erving Goffman, on peut les concevoir comme des motifs d'« inconfort interactionnel ». Cette mise en évidence de l'inconfort interactionnel montre la nécessité de ne pas se limiter à une sociologie de la brûlure grave qui s'attarderait seulement sur les ajustements des interactions. A partir des travaux d'Axel Honneth sur la reconnaissance, il est possible de lire cette gestion des situations d'interaction dans une autre optique, celle qui, pour le grand brûlé, consiste à se préserver du mépris. Ce travail met l'accent sur des habiletés interactionnelles, des compétences qui fonctionnent comme des ressorts et permettent au grand brûlé de gérer des situations susceptibles de conduire au mépris. En s'appuyant sur des situations d'interaction racontées, deux formes de lutte individuelle, de quête de reconnaissance, peuvent être dégagées : d'une part, la « lutte contre » la trop grande visibilité et contre la prégnance de certains préjugés et, d'autre part, la « lutte pour » faire connaître des aspects invisibles ou moins visibles de la brûlure grave. - This thesis analyzes the "factual" and physical ordeal of a severe burn as experienced by victims of severe facial burns. In a few seconds, an accident provokes a biographical rupture and persons involved need time to integrate their new status. This thesis concentrates on the "reconstruction" modes of the relationship with oneself and with others, and on attempts to find an impossible "normal appearance" in public life. While being attentive to the modalities of interaction, the study uses comprehensive sociology based on observations and interviews. This thesis brings into sociology litde known views of those suffering severe facial burns. These views supplement certain media representations that influence perceptions and visibility of the people involved. Applying the concept of test, a key concept of pragmatic sociology, the progression of a severely burned person can be described by focusing on the initial moment: the accident. The recounting of this first challenge reveals the severely burned person's efforts to link the "before" and "after" the accident. A continuum of challenges follows. These tests occur when the severely burned person physically faces others in a public space and when visible discomfort and embarrassment show, reactions which we consider, following Erving Goffman's works, as situations of "interactional discomfort." Emphasis on interactional discomfort shows the necessity of expanding the sociology of severe burns to more than just adjustments to interactions. Based on Axel Honneth's works, we can read the management of interactions from another point of view, in which the severely burned person tries to avoid contempt. This work emphasizes interactional aptitudes, skills that act like rebounding springs, and allow the severely burned person to manage situations that might lead to contempt. Starting with descriptions of interactions, we have determined two forms of individual struggle that appear to be a search for recognition: on one hand, the "struggle against" too much visibility and against the strength of certain prejudices, and, on the other hand, a "struggle for" making known rtain invisible or less visible aspects of a severe burn.
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This research consisted of five laboratory experiments designed to address the following two objectives in an integrated analysis: (1) To discriminate between the symbol Stop Ahead warning sign and a small set of other signs (which included the word-legend Stop Ahead sign); and (2) To analyze sign detection, recognizability, and processing characteristics by drivers. A set of 16 signs was used in each of three experiments. A tachistoscope was used to display each sign image to a respondent for a brief interval in a controlled viewing experiment. The first experiment was designed to test detection of a sign in the driver's visual field; the second experiment was designed to test the driver's ability to recognize a given sign in the visual field; and the third experiment was designed to test the speed and accuracy of a driver's response to each sign as a command to perform a driving action. A fourth experiment tested the meanings drivers associated with an eight-sign subset of the 16 signs used in the first three experiments. A fifth experiment required all persons to select which (if any) signs they considered to be appropriate for use on two scale model county road intersections. The conclusions are that word-legend Stop Ahead signs are more effective driver communication devices than symbol stop-ahead signs; that it is helpful to drivers to have a word plate supplementing the symbol sign if a symbol sign is used; and that the guidance in the Manual on Uniform Traffic Control Devices on the placement of advance warning signs should not supplant engineering judgment in providing proper sign communication at an intersection.
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L'objectif de cette recherche est d'explorer l'impact des abus sexuels tel que perçu par des personnes adultes ayant été victimes dans leur enfance. Une attention particulière est portée sur l'évolution de cette perception. A cette fin, deux groupes de personnes ont été sollicités : des patients suivis en thérapie de groupe dans un centre spécialisé et des personnes ayant terminé une thérapie centrée sur les abus sexuels depuis au moins cinq ans.Des entretiens semi-structurés ont été menés tous les six mois pendant deux ans avec six femmes en thérapie, ainsi qu'avec trois femmes et un homme ayant terminé leur travail thérapeutique à ce sujet.L'analyse qualitative, inspirée de l'IPA, a révélé huit thèmes. A la recherche de la normalité, Vie intime et sexualité, et Du secret à la reconnaissance sont trois des problématiques majeures présentées par les femmes aux premiers entretiens. L'analyse révèle l'évolution de ces thèmes au cours des deux ans et les « témoins de l'après-thérapie » donnent des pistes quant aux suites possibles. Les participants témoignent également de leurs diverses Démarches thérapeutiques. Question de survie est un thème faisant trait à la dissociation structurelle de la personnalité telle qu'elle apparaît dans le discours des participants et telle qu'ils la décrivent. De la réviviscence au souvenir, Attribution de sens et Vivre après amènent chacun des aspects spécifiques liés à la résilience et ultimement à l'épanouissement.Ces résultats font ressortir des thématiques qui se révèlent être particulièrement difficiles pour ces personnes ayant été abusées sexuellement dans leur enfance, tout en soulignant l'évolution possible au fil du temps et à l'aide des thérapies. Ils révèlent également les manières dont le traumatisme est peu à peu intégré par les participants dans leur histoire de vie.This study's aim is to explore how survivors perceive the impact on their adult life of child sexual abuse and how it changes over time. To this effect, two groups of people were solicited: patients involved in group therapy in a specialised treatment centre and people who had finished therapy focused on the trauma caused by the abuse at least five years prior to this study.Semi-structured interviews were conducted at 6-month intervals over two years with six women in therapy. Three women and one man who had finished therapy accepted to share their experience.Qualitative analysis inspired by IPA revealed eight themes. Searching for normality, Tuning feelings with sexual life, and From secrecy to acknowledgment are three of the main issues presented by the women at the initial interviews. The analysis reveals how these themes evolve over the two years, while the participants who have finished their therapy give insights of possible futures. Participants also reflected on their various Therapeutical experiences. A matter of survival relates to structural dissociation of the personality as it appears in the participants' discourse and as they describe it. Placing the memory in the past, Making meaning, and And life goes on each bring out specific aspects linked to resiliency and finally to thriving.These results highlight the issues that are particularly difficult in dealing with the aftermaths of child sexual abuse and underline their possible transformation with time and therapy. They also reveal the ways in which the trauma is gradually integrated by the participants into their life-history.
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This study is one of the first studies to approach workplace bullying cross-culturally. It sought to compare employees' understanding of workplace bullying in two different world regions: Central America and Southern Europe, regarding three aspects of workplace bullying: psychological vs. physical harassment, hierarchical vs. horizontal bullying, and direct vs. indirect aggression. A convenience sample of 246 workers provided their own definition of workplace bullying through a single, open-ended question. The results showed that employees from Central America emphasized the physical component of workplace bullying more than the Southern European employees. However, similarities in the conceptualization of workplace bullying across both cultures were found as well. Both Southern European and Central American employees defined workplace bullying mainly as a hierarchical phenomenon, where the aggression took the form of direct strategies. Such differences and similarities bring to the field some positive inputs for the development and implementation of different strategies for dealing effectively with this phenomenon.
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The present work deals with quantifying group characteristics. Specifically, dyadic measures of interpersonal perceptions were used to forecast group performance. 46 groups of students, 24 of four and 22 of five people, were studied in a real educational assignment context and marks were gathered as an indicator of group performance. Our results show that dyadic measures of interpersonal perceptions account for final marks. By means of linear regression analysis 85% and 85.6% of group performance was respectively explained for group sizes equal to four and five. Results found in the scientific literature based on the individualistic approach are no larger than 18%. The results of the present study support the utility of dyadic approaches for predicting group performance in social contexts.