973 resultados para Forced-choice method
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Relações de equivalência podem ser definidas como relações arbitrárias capazes de tornar diferentes estímulos intercambiáveis em muitas situações. Isso implica que os elementos que compõem uma classe de estímulos equivalentes devem transferir funções entre si. Este trabalho compreende dois estudos que possuem em comum a formação de classes de equivalência entre expressões faciais e figuras abstratas e o uso de medidas não convencionais de transferência de função. No Experimento 1, foram treinadas relações condicionais entre expressões faciais (A) e estímulos abstratos (conjuntos B e C) e entre os estímulos do conjunto C com os de outro conjunto (D). A equivalência foi testada pelas relações D-B. ‘A’ era composto por fotografias que expressavam alegria, raiva e nojo, enquanto B, C e D se compunham por três figuras abstratas cada. Era então pedido ao participante que avaliasse os estímulos abstratos D1, D2 e D3 de acordo com um conjunto de escalas bipolares. Foi encontrada correspondência entre as avaliações das expressões faciais feitas pelo grupo controle e as avaliações dos estímulos D pelo grupo experimental. O uso de estímulos significativos e de medidas de transferência que não envolviam escolhas forçadas possibilitaram uma validação independente do modelo de equivalência, mostrando que estímulos arbitrários podem adquirir 'significado' similar ao de expressões faciais. Os resultados permitem ainda avaliar o grau em que os símbolos adquiriram o significado dos referentes. O Experimento 2 considerou o fato de que uma expressão facial ameaçadora em meio a expressões amigáveis é selecionada mais rapidamente que uma expressão amigável em meio a ameaçadoras e verificou se o mesmo ocorreria com os estímulos que se tornassem equivalentes a elas. As mesmas relações do Experimento 1 foram treinadas e testadas. Um pós-teste dispunha três figuras relacionadas à mesma expressão facial e uma que pertencia à classe de outro rosto. O participante devia selecionar rapidamente essa última. Os símbolos relacionados à expressão ameaçadora foram selecionados mais rapidamente que os relacionados à face amigável, indicando que esse efeito pode se transferir através de relações de equivalência.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The main aim of this paper was to use the REZZ software to calculate the tank volume rainwater harvesting system. For this purpose, rain data of Ponta Grossa-PR-Brazil were used considering different statistical treatment (average, 75%, 85%, 95% and 99% of confidence) and different roof areas (50, 80, 120 and 200 m2). The harvesting system was considered only for toilet flush in households with 3, 4 and 5 inhabitants. There were applied the following methods/concepts: Flow equalization (Rippl); Brazilian method as well the English and German practical methods. Further, the mass-balance was simulated for some conditions. All considered methods are described in NBR15527/07, the Brazilian standard for rainwater harvesting. As expected, the results pointed out for huge differences depending on the choice method and the statistical treatment of the rain data. The REZZ appliance showed to be useful thus permitting to set different conditions and to obtain rapid results in order to assist designers to adopt the best cistern volume for each particular case.
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Stereoscopic depth perception utilizes the disparity cues between the images that fall on the retinae of the two eyes. The purpose of this study was to determine what role aging and optical blur play in stereoscopic disparity sensitivity for real depth stimuli. Forty-six volunteers were tested ranging in age from 15 to 60 years. Crossed and uncrossed disparity thresholds were measured using white light under conditions of best optical correction. The uncrossed disparity thresholds were also measured with optical blur (from +1.0D to +5.0D added to the best correction). Stereothresholds were measured using the Frisby Stereo Test, which utilizes a four-alternative forced-choice staircase procedure. The threshold disparities measured for young adults were frequently lower than 10 arcsec, a value considerably lower than the clinical estimates commonly obtained using Random Dot Stereograms (20 arcsec) or Titmus Fly Test (40 arcsec) tests. Contrary to previous reports, disparity thresholds increased between the ages of 31 and 45 years. This finding should be taken into account in clinical evaluation of visual function of older patients. Optical blur degrades visual acuity and stereoacuity similarly under white-light conditions, indicating that both functions are affected proportionally by optical defocus.
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We examined achromatic contrast discrimination in asymptomatic carriers of 11778 Leber`s hereditary optic neuropathy (LHON 18 controls) and 18 age-match were also tested. To evaluate magnocellular (MC) and Parvocellular (PC) contrast discrimination, we used a version of Pokorny and Smith`s (1997) Pulsed/steady-pedestal paradigms (PPP/SPP) thought to be detected via PC and MC pathways, respectively. A luminance pedestal (four 1 degrees x 1 degrees squares) was presented on a 12 cd/m(2) surround. The luminance of one of the squares (trial square, TS) was randomly incremented for either 17 or 133 ms. Observers had to detect the TS, in a forced-choice task, at each duration, for three pedestal levels: 7, 12, 19 cd/m(2). In the SPP, the pedestal was fixed, and the TS was modulated. For the PPP, all four pedestal squares pulsed for 17 or 133 ms, and the TS was simultaneously incremented or decremented. We found that contrast discrimination thresholds of LHON carriers were significantly higher than controls` in the condition with the highest luminance of both paradigms, implying impaired contrast processing with no evidence of differential sensitivity losses between the two systems. Carriers` thresholds manifested significantly longer temporal integration than controls in the SPP, consistent with slowed MC responses. The SPP and PPP paradigms can identify contrast and temporal processing deficits in asymptomatic LHON carriers, and thus provide an additional tool for early detection and characterization of the disease.
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OBJETIVO: Determinar a taxa de sucesso da broncoscopia flexível como primeira opção na remoção de corpos estranhos das vias aéreas em adultos. MÉTODOS: Estudo retrospectivo de todos os pacientes adultos (acima de 18 anos) com aspiração de corpo estranho submetidos a broncoscopia no Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, em São Paulo (SP). RESULTADOS: A amostra foi constituída por 40 pacientes adultos, com média de idade de 52 anos (variação: 18-88 anos). A mediana do tempo de permanência do corpo estranho na via aérea foi de 15 dias (variação: 12 h a 10 anos). Todos os pacientes foram submetidos primeiramente a broncoscopia flexível diagnóstica. A retirada do corpo estranho por meio de broncoscopia flexível foi bem-sucedida em 33 dos pacientes (82,5%). Em 1 paciente, um objeto metálico alojado na árvore brônquica distal requereu o uso de fluoroscopia. Seis pacientes (15%) foram submetidos a broncoscopia rígida devido a dispneia induzida por corpo estranho traqueal, em 2, e porque o corpo estranho era muito grande para as pinças flexíveis, em 4. A broncoscopia falhou em apenas 1 paciente, que portanto necessitou de broncotomia. CONCLUSÕES: Embora a broncoscopia rígida seja considerada o padrão ouro na remoção de corpos estranhos na via aérea, nossa experiência mostrou que a broncoscopia flexível pode ser utilizada segura e eficientemente no diagnóstico e tratamento de pacientes adultos estáveis.
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Since the Nineties, the process of globalization has caused a sharp increase in the real and financial integration of the worldwide economy, reducing the obstacles to international trade and minimizing the cost of transaction. The entrance of foreign firms in the domestic market has deeply modified the competitive situation of Italian enterprises, which have been forced to change their strategies in order to cope with those of the new competitors. In this scenario, internationalization is no longer one of the different strategic options available for the firm, but it becomes a forced choice to maintain or acquire a competitive advantage sustainable over time. Internationalization strategies of SMEs, however, are hindered by the shortage of financial resources and entrepreneurial skills, therefore this kind of firms tends toward light forms of foreign expansion, like export and subcontracting. Despite this, many studies have demonstrated that the district localisation increases the firms’ productivity and innovative capacity, so their competiveness both at a domestic and international level. The majority of these empirical contributions has focused mainly on the analysis of commercial flows, confirming that district enterprises reach a superior international performance compared to their external competitors. On the contrary, only few works have tried to evaluate the existence of a district effect on the firms’ ability to invest abroad, but the obtained results are not straightforward. One of the reason of these conclusions is that the phenomena has been analysed without taking into account the differences existing between districts in terms of enterprises’ dimension, diffusion of industrial groups and, above all, the sector of productive specialization, because the technological content of production could improve the innovativeness of district firms, allowing them to adopt advanced forms of internationalisation as foreign direct investments (FDI). The aim of the thesis is to further investigate the district effect on internationalisation, trough an econometric analysis of the international strategies carried out by firms localised in three different local system of production characterised by different technological specialization.
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This research tests the hypothesis that knowledge of derivational morphology facilitates vocabulary acquisition in beginning adult second language learners. Participants were mono-lingual English-speaking college students aged 18 years and older enrolled inintroductory Spanish courses. Knowledge of Spanish derivational morphology was tested through the use of a forced-choice translation task. Spanish lexical knowledge was measured by a translation task using direct translation (English word) primes and conceptual (picture) primes. A 2x2x2 mixed factor ANOVA examined the relationships between morphological knowledge (strong, moderate), error type (form-based, conceptual), and prime type (direct translation, picture). The results are consistent with the existence of a relationship between knowledge of derivational morphology andacquisition of second language vocabulary. Participants made more conceptually-based errors than form-based errors F (1,22)=7.744, p=.011. This result is consistent with Clahsen & Felser’s (2006) and Ullman’s (2004) models of second language processing. Additionally, participants with Strong morphological knowledge made fewer errors onthe lexical knowledge task than participants with Moderate morphological knowledge t(23)=-2.656, p=.014. I suggest future directions to clarify the relationship between morphological knowledge and lexical development in adult second language learners.
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Transcranial magnetic stimulation (TMS) was used to study visuospatial attention processing in ten healthy volunteers. In a forced choice recognition task the subjects were confronted with two symbols simultaneously presented during 120 ms at random positions, one in the left and the other in the right visual field. The subject had to identify the presented pattern out of four possible combinations and to press the corresponding response key within 2 s. Double-pulse TMS (dTMS) with a 100-ms interstimulus interval (ISI) and an intensity of 80% of the stimulator output (corresponding to 110-120% of the motor threshold) was applied by a non-focal coil over the right or left posterior parietal cortex (PPC, corresponding to P3/P4 of the international 10-20 system) at different time intervals after onset of the visual stimulus (starting at 120 ms, 270 ms and 520 ms). Double-pulse TMS over the right PPC starting at 270 ms led to a significant increase in percentage of errors in the contralateral, left visual field (median: 23% with TMS vs 13% without TMS, P=0.0025). TMS applied earlier or later showed no effect. Furthermore, no significant increase in contra- or ipsilateral percentage of errors was found when the left parietal cortex was stimulated with the same timing. These data indicate that: (1) parietal influence on visuospatial attention is mainly controlled by the right lobe since the same stimulation over the left parietal cortex had no significant effect, and (2) there is a vulnerable time window to disturb this cortical process, since dTMS had a significant effect on the percentage of errors in the contralateral visual hemifield only when applied 270 ms after visual stimulus presentation.
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Background: Emotional processing in essential hypertension beyond self-report questionnaire has hardly been investigated. The aim of this study is to examine associations between hypertension status and recognition of facial affect. Methods: 25 healthy, non-smoking, medication-free men including 13 hypertensive subjects aged between 20 and 65 years completed a computer-based task in order to examine sensitivity of recognition of facial affect. Neutral faces gradually changed to a specific emotion in a pseudo-continuous manner. Slides of the six basic emotions (fear, sadness, disgust, happiness, anger, surprise) were chosen from the „NimStim Set“. Pictures of three female and three male faces were electronically morphed in 1% steps of intensity from 0% to 100% (36 sets of faces with 100 pictures each). Each picture of a set was presented for one second, ranging from 0% to 100% of intensity. Participants were instructed to press a stop button as soon as they recognized the expression of the face. After stopping a forced choice between the six basic emotions was required. As dependent variables, we recorded the emotion intensity at which the presentation was stopped and the number of errors (error rate). Recognition sensitivity was calculated as emotion intensity of correctly identified emotions. Results: Mean arterial pressure was associated with a significantly increased recognition sensitivity of facial affect for the emotion anger (ß = - .43, p = 0.03*, Δ R2= .110). There was no association with the emotions fear, sadness, disgust, happiness, and surprise (p’s > .0.41). Mean arterial pressure did not relate to the mean number of errors for any of the facial emotions. Conclusions: Our findings suggest that an increased blood pressure is associated with increased recognition sensitivity of facial affect for the emotion anger, if a face shows anger. Hypertensives perceive facial anger expression faster than normotensives, if anger is shown.
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Recent studies have shown that women are more sensitive than men to subtle cuteness differences in infant faces. It has been suggested that raised levels in estradiol and progesterone may be responsible for this advantage. We compared young women's sensitivity to computer-manipulated baby faces varying in cuteness. Thirty-six women were tested once during ovulation and once during the luteal phase of their menstrual cycle. In a two alternative forced-choice experiment, participants chose the baby which they thought was cuter (Task 1), younger (Task 2), or the baby that they would prefer to babysit (Task 3). Saliva samples to assess levels of estradiol, progesterone and testosterone were collected at each test session. During ovulation, women were more likely to choose the cuter baby than during the luteal phase, in all three tasks. These results suggest that cuteness discrimination may be driven by cyclic hormonal shifts. However none of the measured hormones were related to increased cuteness sensitivity. We speculate that other hormones than the ones measured here might be responsible for the increased sensitivity to subtle cuteness differences during ovulation.
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The present study was designed to investigate the influences of type of psychophysical task (two-alternative forced-choice [2AFC] and reminder tasks), type of interval (filled vs. empty), sensory modality (auditory vs. visual), and base duration (ranging from 100 through 1,000 ms) on performance on duration discrimination. All of these factors were systematically varied in an experiment comprising 192 participants. This approach allowed for obtaining information not only on the general (main) effect of each factor alone, but also on the functional interplay and mutual interactions of some or all of these factors combined. Temporal sensitivity was markedly higher for auditory than for visual intervals, as well as for the reminder relative to the 2AFC task. With regard to base duration, discrimination performance deteriorated with decreasing base durations for intervals below 400 ms, whereas longer intervals were not affected. No indication emerged that overall performance on duration discrimination was influenced by the type of interval, and only two significant interactions were apparent: Base Duration × Type of Interval and Base Duration × Sensory Modality. With filled intervals, the deteriorating effect of base duration was limited to very brief base durations, not exceeding 100 ms, whereas with empty intervals, temporal discriminability was also affected for the 200-ms base duration. Similarly, the performance decrement observed with visual relative to auditory intervals increased with decreasing base durations. These findings suggest that type of task, sensory modality, and base duration represent largely independent sources of variance for performance on duration discrimination that can be accounted for by distinct nontemporal mechanisms.
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This research compares the methodological tools employed in NOS research, with analysis of what the comparison implies about the structure of nature of science knowledge. Descriptions of practicing teachers’ nature of science conceptions were compared based on data collected from forced choice responses, responses to a qualitative survey, and course writing samples. Participants’ understandings were scored differently on the Views of Nature of Science Questionnaire (VNOS) than the forced-choice measure, Scientific Thinking and Internet Learning Technologies (STILT). In addition, analysis of the writing samples and observations combined with interviews portrayed more sophisticated, but more variable, understandings of the nature of science than was evidenced by either the survey or the forced-choice measure. The differences between data collection measures included the degree to which they drew upon context bound or context general reasoning, the degree to which they required students to move beyond the simple intelligibility of their responses and allowed students to explore the fruitfulness of the constructs, as well as the degree to which they revealed the interconnection of participants NOS conceptions. In light of the different portrayals of a participants NOS conceptions yielded by these different measures, we call for the use of crystallization as a methodological referent in research.