217 resultados para visual discrimination
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Nicotine consumption is higher for people within the schizophrenia spectrum compared to controls. This observation supports the self-medication hypothesis, that nicotine relieves symptoms in, for example, schizophrenia patients. We tested whether performance in an endophenotype of schizophrenia (visual backward masking, VBM) is modulated by nicotine consumption in i) smoking and non-smoking schizophrenia patients, their first-degree relatives, and age-matched controls, ii) non-smoking and smoking university students, and iii) non-smoking, early and late onset nicotine smokers. Overall, our results confirmed that VBM deficits are an endophenotype of schizophrenia, i.e., deficits were highest in patients, followed by their relatives, students scoring high in Cognitive Disorganisation, and controls. Moreover, we found i) beneficial effects of chronic nicotine consumption on VBM performance, in particular with increasing age, and ii) little impact of clinical status. alone or in interactionwith nicotine consumption on VBMperformance. Given the younger age of undergraduate students (up to 30 years) versus controls and patients (up to 66 years),we propose that age-dependent VBMdeficits emergewhen schizotypy effects are targeted in populations of a larger age range, but that nicotine consumption might counteract these deficits (supporting the self-medication hypothesis).
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PURPOSE: To investigate the functional outcome of eyes with neovascular AMD (nAMD) and subretinal fluid (SRF) refractory to treatment with ranibizumab. METHODS: Retrospective chart review of consecutive treatment-refractory SRF in nAMD despite monthly ranibizumab injections during 12 months or more. Data were evaluated for baseline characteristics, location of the refractory SRF, mean visual acuity (VA) change, number of injections, and timepoint of first complete disappearance of SRF. RESULTS: Forty-five eyes in 44 patients (mean age of 76 years) were included. The mean follow-up was 32.4 months (range 12-73 months). The mean number of injections was 11.6 in the first year and 27.5 over follow-up. The refractory SRF was located subfoveally in 66.7 %. In 12 eyes (26.7 %), complete absorption of SRF was found after a mean of 22.6 months (range, 13-41 months). Mean VA increased by 10.4, 8.2, and 8.6 letters by month 12, 24, and 36, respectively. CONCLUSIONS: Neovascular AMD with SRF refractory to monthly retreatment with ranibizumab may still allow good and maintained visual improvement, even if the fluid is located subfoveally. SRF may progressively absorb under continuous monthly treatment. The necessity to treat refractory SRF with monthly injections could be questioned and would need future investigations.
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BACKGROUND: Best corrected visual acuity (BCVA) of 0.8 or above in AMD patients can sometimes correspond to poor macular function inducing a serious visual handicap. Microperimetry can be used to objectivize this difference. PATIENTS AND METHODS: A retrospective study was undertaken on 233 files of AMD patients of whom 82 had had a microperimetry. BCVA was compared with microperimetry performance. All examinations were performed in an identical setting by the same team of 3 persons. RESULTS: Among the 82 patients included, 32 (39.0%) had a BCVA equal to or above 0.8 even though their microperimetry performance was lower than 200/560 db. 10 of them (12.2% of total) had an even poorer microperimetry below 120/560 db indicating poor macular function. CONCLUSIONS: More than a third of the AMD patients had a bad or very bad microperimetry performance in parallel with a good visual acuity. Microperimetry is a valuable tool to assess and follow real macular function in AMD patients when visual acuity alone can be misleading.
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PURPOSE: Laparoscopic surgery represents specific challenges, such as the reduction of a three-dimensional anatomic environment to two dimensions. The aim of this study was to investigate the impact of the loss of the third dimension on laparoscopic virtual reality (VR) performance. METHODS: We compared a group of examinees with impaired stereopsis (group 1, n = 28) to a group with accurate stereopsis (group 2, n = 29). The primary outcome was the difference between the mean total score (MTS) of all tasks taken together and the performance in task 3 (eye-hand coordination), which was a priori considered to be the most dependent on intact stereopsis. RESULTS: The MTS and performance in task 3 tended to be slightly, but not significantly, better in group 2 than in group 1 [MTS: -0.12 (95 % CI -0.32, 0.08; p = 0.234); task 3: -0.09 (95 % CI -0.29, 0.11; p = 0.385)]. The difference of MTS between simulated impaired stereopsis between group 2 (by attaching an eye patch on the adominant eye in the 2nd run) and the first run of group 1 was not significant (MTS: p = 0.981; task 3: p = 0.527). CONCLUSION: We were unable to demonstrate an impact of impaired examinees' stereopsis on laparoscopic VR performance. Individuals with accurate stereopsis seem to be able to compensate for the loss of the third dimension in laparoscopic VR simulations.
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Recognition of environmental sounds is believed to proceed through discrimination steps from broad to more narrow categories. Very little is known about the neural processes that underlie fine-grained discrimination within narrow categories or about their plasticity in relation to newly acquired expertise. We investigated how the cortical representation of birdsongs is modulated by brief training to recognize individual species. During a 60-minute session, participants learned to recognize a set of birdsongs; they improved significantly their performance for trained (T) but not control species (C), which were counterbalanced across participants. Auditory evoked potentials (AEPs) were recorded during pre- and post-training sessions. Pre vs. post changes in AEPs were significantly different between T and C i) at 206-232ms post stimulus onset within a cluster on the anterior part of the left superior temporal gyrus; ii) at 246-291ms in the left middle frontal gyrus; and iii) 512-545ms in the left middle temporal gyrus as well as bilaterally in the cingulate cortex. All effects were driven by weaker activity for T than C species. Thus, expertise in discriminating T species modulated early stages of semantic processing, during and immediately after the time window that sustains the discrimination between human vs. animal vocalizations. Moreover, the training-induced plasticity is reflected by the sharpening of a left lateralized semantic network, including the anterior part of the temporal convexity and the frontal cortex. Training to identify birdsongs influenced, however, also the processing of C species, but at a much later stage. Correct discrimination of untrained sounds seems to require an additional step which results from lower-level features analysis such as apperception. We therefore suggest that the access to objects within an auditory semantic category is different and depends on subject's level of expertise. More specifically, correct intra-categorical auditory discrimination for untrained items follows the temporal hierarchy and transpires in a late stage of semantic processing. On the other hand, correct categorization of individually trained stimuli occurs earlier, during a period contemporaneous with human vs. animal vocalization discrimination, and involves a parallel semantic pathway requiring expertise.
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PurposeTo evaluate the impact of traditional French summer vacation on visual acuity and spectral domain-optical coherence tomography (SD-OCT) of Wet AMD patients being treated with intravitreal Ranibizumab.MethodsThis was a consecutive, comparative, single-centre, prospective analysis. All patients who were being treated with intravitreal injection of 0.5 mg ranibizumab at Cergy Pontoise Hospital, Department of Ophthalmology between July 2013 and September 2014 were included. Patients were divided into two groups: (A) patients who skipped one ranibizumab intravitreal injection during holidays, and (B) patients who received injection during their holidays. Evaluations occurred prior to traditional holiday (baseline) and 2 months later, consisting of BCVA using ETDRS, and a complete ophthalmic examination that included slit-lamp biomicroscopy, fundus examination, fluorescein angiography (FA), indocyanine green angiography (ICGA), and spectral domain-optical coherence tomography (SD-OCT). All patients were being treated with PRN anti-VEGF regimen and criteria for reinjection included a visual acuity loss >5 ETDRS letters and/or an increase of central retinal thickness, presence of subretinal fluid, intraretinal fluid, or pigment epithelium detachment. If reinjection criteria were not met, patients were advised to return in 4 weeks.ResultsThe mean visual acuity change was -0.071±0.149 (LogMAR) in group A and +0.003±0.178 in group B (P=0.041). At the second visit (2 months after preholidays visit), 61.8% of patients in group A had SRF and/or intraretinal cysts, and only 27.6% of patients in group B. There was a significant difference in the persistence of fluid between the two groups (P=0.007, χ(2)-test).ConclusionThis cases series demonstrated the detrimental impact of holidays on visual acuity in patients treated with ranibizumab for AMD, which, in spite of their treatment regimen, still leave in vacation. Therefore, it is important to convey the message of treatment adherence to patients, despite their need of holidays.
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Malgré une société de plus en plus tolérante, la discrimination reste un problème d'actualité. Pour expliquer la formation des comportements discriminatoires, la recherche en psychologie sociale a traditionnellement étudié la discrimination comme un phénomène intergroupe, notamment à travers la théorie de l'identité sociale (Tajfel & Turner, 1979). Toutefois, cette approche ne permet pas de comprendre comment des individus peuvent de nos jours s'engager dans des comportements discriminatoires tout en sachant que ces actes sont répréhensibles socialement et pénalement. C'est à cette problématique que nous nous sommes attelés dans la présente recherche. De nombreuses études ont mis en évidence le fait que des individus étaient prêts à commettre des actes discriminatoires pour autant qu'ils puissent les justifier (Crandall & Eshleman, 2003). Nous proposons de contribuer à la compréhension de ce phénomène grâce au concept de désengagement moral définit comme le processus par lequel des individus justifient leurs comportements immoraux pour les rendre acceptable. Ce concept a initialement été développé de manière conceptuelle par Bandura (1990) pour comprendre les processus cognitifs amenant des individus à se comporter de manière immorale. Dans le cadre de notre recherche, nous proposons de développer le concept de désengagement moral pour des actes discriminatoires (DMD) ainsi que sa mesure. Plus particulièrement, nous proposons de conceptualiser le DMD comme une différence individuelle permettant aux individus de s'engager dans des comportements discriminatoires en toute impunité à travers un processus anticipatoire de justification. Ces justifications visent à prouver le bien-fondé des actes de discrimination envisagés, ainsi perçus comme bénins, acceptables, voire désirables. Deux des trois étapes envisagées pour le développement de la mesure ont déjà été réalisées. Les résultats obtenus sont prometteurs quant à la structure et la validité de la mesure.
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Gender inequalities remain an issue in our society and particularly in the workplace. Several factors can explain this gender difference in top-level managerial positions such as career ambitions but also biases against women. In our chapter, we propose a model explaining why gender inequalities and particularly discrimination against women is still present in our societies despite social norms and existing legislation on gender equality. To this purpose, we review research on discrimination through two different approaches, (a) a prejudice approach through the justification-suppression model developed by Crandall and Eshleman (2003) and (b) a power approach through the social dominance theory (Pratto, Sidanius, Stallworth, & Malle, 1994; Sidanius & Pratto, 1999). In our work, we integrate these two approaches and propose a model of gender prejudice, power and discrimination. The integration of these two approaches contributes to a better understanding of how discrimination against women is formed and maintained over time.
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De nos jours, les comportements discriminatoires sont mal vus par la société. On tend à montrer du doigt les personnes s'engageant dans de tels comportements et à médiatiser les entreprises prises en flagrant délit de discrimination, tant au niveau du processus d'embauche (p. ex., rejet systématique des candidatures venant de candidats d'origine étrangère), qu'au niveau des différences de traitement au sein des entreprises (p. ex., différence de salaires entre les femmes et les hommes). Si les comportements discriminatoires sont si mal perçus, pourquoi sont-ils toujours d'actualité ? Comment est-ce que des personnes s'engageant dans de tels comportements peuvent garder à la fois une image positive d'eux-mêmes et éviter de se faire réprimander par d'autres personnes qui pourraient avoir connaissance de leurs mauvais agissements ? C'est à cette problématique que je m'atèle dans ma recherche. A travers une expérience sur le thème de la discrimination à l'embauche, je démontre que les individus ayant tendance à se désengager moralement de leur propre action sont plus à même de s'engager dans des comportements discriminatoires que les autres individus. Le désengagement moral est un processus par lequel les individus justifient leur propre comportement non-éthique afin de les rendre acceptable (Bandura, 1986). En particulier, les résultats ont révélé que cette relation entre désengagement moral et discrimination est modéré par le degré de préjugés des individus. Parmi les individus ayant des préjugés marqués envers les étrangers, plus leur tendance au désengagement moral est élevé, plus ils sont à même de s'engager dans des comportements discriminatoires.
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BACKGROUND: Existing prediction models for mortality in chronic obstructive pulmonary disease (COPD) patients have not yet been validated in primary care, which is where the majority of patients receive care. OBJECTIVES: Our aim was to validate the ADO (age, dyspnoea, airflow obstruction) index as a predictor of 2-year mortality in 2 general practice-based COPD cohorts. METHODS: Six hundred and forty-six patients with COPD with GOLD (Global Initiative for Chronic Obstructive Lung Disease) stages I-IV were enrolled by their general practitioners and followed for 2 years. The ADO regression equation was used to predict a 2-year risk of all-cause mortality in each patient and this risk was compared with the observed 2-year mortality. Discrimination and calibration were assessed as well as the strength of association between the 15-point ADO score and the observed 2-year all-cause mortality. RESULTS: Fifty-two (8.1%) patients died during the 2-year follow-up period. Discrimination with the ADO index was excellent with an area under the curve of 0.78 [95% confidence interval (CI) 0.71-0.84]. Overall, the predicted and observed risks matched well and visual inspection revealed no important differences between them across 10 risk classes (p = 0.68). The odds ratio for death per point increase according to the ADO index was 1.50 (95% CI 1.31-1.71). CONCLUSIONS: The ADO index showed excellent prediction properties in an out-of-population validation carried out in COPD patients from primary care settings. © 2014 S. Karger AG, Basel.