Efeito do álcool na ilusão da máscara côncava: uma revisão / Effect of alcohol on the hollow-face illusion: a review / Efecto del alcohol en la ilusión de la máscara cóncava: una revisión

A ilusão da máscara côncava ocorre quando o observador a determinada distância percebe uma máscara facial côncava como convexa. Isso pode ser explicado pela sobreposição dos processos de alta ordem da percepção visual sobre os de baixa ordem. Pesquisas com indivíduos intoxicados e em Síndrome de Abstinência do Álcool (SAA) revelaram um prejuízo em perceber essa ilusão. O objetivo foi realizar uma revisão da literatura sobre o tema. Após buscas em bases indexadas, cinco pesquisas foram encontradas. Os resultados para os alcoolistas em SAA moderada revelaram uma menor frequência nas respostas de percepção da ilusão. Os resultados foram contraditórios quanto ao grupo de alcoolistas com SSA leve. Pesquisas futuras com metodologias diferentes são necessárias para testar as hipóteses explicativas da ilusão da máscara côncava em alcoolistas. É importante considerar os processos de tomada de decisão do observador diante da observação dos objetos como base a Teoria de Detecção de Sinal (TDS)

The hollow-face illusion happens when the observer perceives a concave facial mask as convex, at a given distance. This can be explained by the overlap of top-down on bottom-up visual processes. Researches demonstrated that intoxicated and Alcohol Withdrawal Syndrome (AWS) individuals had deficit in perceiving this illusion. This study aimed to review the literature on this topic. A survey of indexed databases found five studies. The results for alcoholics with moderate AWS were similar and showed a lower frequency in the answers of illusion perception. However, results were contradictory to the alcoholic group with mild AWS. Future researches with different methodologies are necessary to test the hollow-face illusion hypotheses in alcoholics. Therefore, it is also important to consider the observer's decision-making processes in the objects observation based on the Signal Detection Theory (SDT)

La ilusión de la máscara cóncava ocurre cuando el observador a cierta distancia percibe una máscara facial cóncava como convexa. Esto puede ser explicado por la superposición de los procesos de alto orden de la percepción visual sobre los de bajo orden. Las investigaciones con individuos intoxicados y en el Síndrome de Abstinencia del Alcohol (SAA) revelaron un perjuicio en percibir esa ilusión. El objetivo fue realizar una revisión de la literatura sobre el tema. Después de buscar en bases indexadas, se encontraron cinco encuestas. Los resultados para los alcohólicos en SAA moderada revelaron una menor frecuencia en las respuestas de percepción de la ilusión. Los resultados fueron contradictorios en cuanto al grupo de alcohólicos con SSA leve. Las investigaciones futuras con metodologías diferentes son necesarias para probar las hipótesis explicativas de la ilusión de la máscara cóncava en alcohólicos. Es importante considerar los procesos de toma de decisión del observador ante la observación de los objetos como base la Teoría de Detección de Señal (TDS)

Efeito do álcool na ilusão da máscara côncava: uma revisão / Effect of alcohol on the hollow-face illusion: a review / Efecto del alcohol en la ilusión de la máscara cóncava: una revisión

A ilusão da máscara côncava ocorre quando o observador a determinada distância percebe uma máscara facial côncava como convexa. Isso pode ser explicado pela sobreposição dos processos de alta ordem da percepção visual sobre os de baixa ordem. Pesquisas com indivíduos intoxicados e em Síndrome de Abstinência do Álcool (SAA) revelaram um prejuízo em perceber essa ilusão. O objetivo foi realizar uma revisão da literatura sobre o tema. Após buscas em bases indexadas, cinco pesquisas foram encontradas. Os resultados para os alcoolistas em SAA moderada revelaram uma menor frequência nas respostas de percepção da ilusão. Os resultados foram contraditórios quanto ao grupo de alcoolistas com SSA leve. Pesquisas futuras com metodologias diferentes são necessárias para testar as hipóteses explicativas da ilusão da máscara côncava em alcoolistas. É importante considerar os processos de tomada de decisão do observador diante da observação dos objetos como base a Teoria de Detecção de Sinal (TDS)

The hollow-face illusion happens when the observer perceives a concave facial mask as convex, at a given distance. This can be explained by the overlap of top-down on bottom-up visual processes. Researches demonstrated that intoxicated and Alcohol Withdrawal Syndrome (AWS) individuals had deficit in perceiving this illusion. This study aimed to review the literature on this topic. A survey of indexed databases found five studies. The results for alcoholics with moderate AWS were similar and showed a lower frequency in the answers of illusion perception. However, results were contradictory to the alcoholic group with mild AWS. Future researches with different methodologies are necessary to test the hollow-face illusion hypotheses in alcoholics. Therefore, it is also important to consider the observer's decision-making processes in the objects observation based on the Signal Detection Theory (SDT)

La ilusión de la máscara cóncava ocurre cuando el observador a cierta distancia percibe una máscara facial cóncava como convexa. Esto puede ser explicado por la superposición de los procesos de alto orden de la percepción visual sobre los de bajo orden. Las investigaciones con individuos intoxicados y en el Síndrome de Abstinencia del Alcohol (SAA) revelaron un perjuicio en percibir esa ilusión. El objetivo fue realizar una revisión de la literatura sobre el tema. Después de buscar en bases indexadas, se encontraron cinco encuestas. Los resultados para los alcohólicos en SAA moderada revelaron una menor frecuencia en las respuestas de percepción de la ilusión. Los resultados fueron contradictorios en cuanto al grupo de alcohólicos con SSA leve. Las investigaciones futuras con metodologías diferentes son necesarias para probar las hipótesis explicativas de la ilusión de la máscara cóncava en alcohólicos. Es importante considerar los procesos de toma de decisión del observador ante la observación de los objetos como base la Teoría de Detección de Señal (TDS)

Efeitos da cor, iluminação e rotação na ilusão estereoscópica da máscara côncava / The hollow face illusion strength in stereoscopic viewing condition under effects of color, ligthning orientation and rotation

Na ilusão da máscara côncava, o reverso côncavo da máscara é percebido como uma face convexa. Esta pesquisa objetivou investigar a robustez dessa ilusão em fotografias de estereogramas da máscara côncava sob variações de cor, iluminação e rotação. Quarenta observadores julgaram como côncava, plana ou convexa máscaras côncavas cinza e policromada, iluminadas por cima, baixo, direita, esquerda, e invertida iluminada por baixo, apresentadas num monitor. A maioria julgou a máscara côncava como convexa. Eles também reproduziram, em centímetros, a profundidade percebida entre a ponta do nariz da máscara e sua base. Não foi observado efeito para a cor, F(1,39)=0,22; p>0,05, mas ocorreu um efeito principal para a direção da iluminação, F(4,156)=11,35; p<0,05. Observou-se uma diferença significativa entre estimativas da posição da máscara côncava monocromada, t(39)=2,12; p<0,05. Maiores estimativas foram designadas às máscaras côncavas posicionadas verticalmente iluminadas por baixo. Estes resultados indicaram a atuação dos processos top-down sobre os bottom-up. (AU)

The hollow-face illusion is an optical illusion in which the perception of a concave mask appears as a convex face. The goal of this study was to investigate the strength of this illusion under different sources of illumination, face color and positioning into stereographic photos. Forty participants judged, in a computer screen, the hollow-face illuminated from above, below, left, and right, and in the upside-down position illuminated from below, as concave, plain or convex. Most of them judged the reverse mask as convex. They also reproduced, in centimeters, the perceived depth of the mask using a retractable tape measure. No significant difference was observed between the colors, F(1,39)=.22; p>.05. But there was an effect in the illumination directions, F(4,156)=11.35; p<.05. The position affected the depth perception of a monochrome hollow-face, t(39)=2.12; p<.05. Higher estimates were designated to the hollow-face in the upright position. These results indicated top-down overlapped bottom-up processing. (AU)

The Unique Theory of Cold Damage Advocated by Medical Practitioners in the Latter Era of the Joseon Dynasty / 의사학

The issue of cold damage is one of the major topics of orthodox medicine in East Asia. From the historical view of point, most of the medical practitioners have turned The Theory of Cold Damage to account as their grounds for justifying their own argument. However, it is rare to find a book related to The Theory of Cold Damage in Korea's traditional medicine. Therefore, people have perceived the research status of cold damage is unsatisfactory. This problem could be analyzed by dividing it into a medicinal herb problems and theory problem. First, the medicinal herbs needed for the prescription based on The Theory of Cold Damage don't grow in the Korean Peninsula. Accordingly, there were a lot of restrictions on the free use of these prescriptions. Nevertheless, Chinese medicinal herbs were essential to even the use of the prescriptions besides The Theory of Cold Damage. Accordingly, such aspects do little explain the point that there were few medicine books about The Theory of Cold Damage in Korea. On the other hand, it is hard to exclude the guess that the medical practitioners in the period of the Joseon Dynasty might have presented a theoretically different opinion about cold damage. This study did intensive research on this. As a result of examining the medical practitioners in the latter period of the Joseon Dynasty perceived 'the cold damage to positive and negative meridians' as the case where a patient got attacked by cold as a pathogenic factor in a state of the kidney deficiency. They presented the verdict that kidney deficiency was mostly incurred by sexual relations, and the cold damage to positive and negative meridians broke out when a patient got attacked by cold as a pathogenic factor after having sex. it is an original standpoint shedding light on the relationship between cold damage and the kidney deficiency. The medical practitioners in the latter period of the Joseon Dynasty used Donguibogam as a major text for study on cold damage. In other words, Donguibogam includes the well-organized theory of Yeoksu school who regarded the comparison between internal damage and external damage as important. The medical practitioners in the latter period of the Joseon Dynasty managed to form the theory of the cold damage to positive and negative meridians by deepening the relationship between internal damage and external damage, which was highlighted in Donguibogam. The medical practitioners in the Joseon Dynasty didn't show a big interest in the literature itself, or the so-called The Theory of Cold Damage, which was mainly due to not only the realistic problem of the lack of medicinal herbs needed for applying the prescription to cold damage but also the difference between their positions on cold damage. Therefore, the idea of insufficient research on The Theory of Cold Damage is no more than a kind of optical illusion. On the contrary, we may assume that the medical practitioners in the Joseon Dynasty understood and developed The Theory of Cold Damage in their own way.

Bandas de mach en radiología / Mach bands in radiology

Mach bands represent optical psychophy-siological edge-enhancement phenomena perceived in different forms by different observers; they originate in adjacent areas of diverse density, giving rise to a thin black strip (negative Mach band) or a white strip (positive Mach band). They can be identifed in simple radiographic examinations, including chest radiography, and also in CT topograms. Proper recognition of Mach bands helps to correctly interpret radiological examinations.

Las bandas de Mach son fenómenos ópticos psicofisiológicos de realce de bordes que se perciben de forma muy variable entre los distintos observadores; se originan en áreas adyacentes de diferente densidad, dando origen a una fina banda negra o blanca, Mach negativo o positivo. Pueden identificarse en los exámenes radiológicos simples, como por ejemplo radiografía de tórax, y también en los topogramas de TC. El adecuado reconocimiento de las bandas de Mach ayuda a interpretar correctamente los exámenes radiológicos.

Análisis de la calidad técnica de los lentes deventa libre con el referente de lentes oftálmicosen pacientes présbitas / Analysis of the technical quality of freedom sale lens with reference in presbiopye patients’ ophthalmic lenses

Los lentes de venta libre, fabricados industrialmente, se adquieren en diferentes lugares sin previo conocimientode su calidad y sin la orientación del personalcalificado.Objetivo: establecer la calidad óptica de los lentes de venta libre.Materiales y métodos: se utilizaron 50 anteojos de venta libre, que fueron elegidos por cada paciente escogiendo la corrección con la que se sentían más cómodos para su trabajo en visión próxima. Después del uso durante 15 días de los lentes descritos, se reemplazaroncon lentes oftálmicos en material CR-39 y la prescripción correspondiente, usados el mismo tiempo. Mediante la construcción de un refractómetro,se determinó la distancia focal y el índice de refracción,obteniendo el número ABBE y la reflectancia.Se midió el poder de vértice posterior, espesor, ságita y densidad.Resultados: con respecto al poder, el paciente siemprese inclinó a escoger los lentes de venta libre que tuvieran mayor aumento, con el fin de buscar magnificación,demostrándose que son pacientes hipercorregidos.Además, la rotulación del poder de estos lentes no correspondió en el 40 por ciento de los casos. La densidad promedio de los lentes de venta libre dio 1,18 g/cm3, el índice de refracción promedio 1,560 y un número ABBE promedio de 30.Conclusiones: debido a estas características los lentes tienen menor espesor, menor peso y mayor dispersión cromática que los lentes de referencia CR-39.

The nonprescription lenses, industrially manufactured,are acquired in different places, without prior knowledge of their quality and without the guidance of qualified personnel.Objective: to establish the optical quality of nonprescriptionlenses.Methods: we used 50 nonprescription eyeglasses, which were elected for each patient in choosing the correction with which they felt more comfortable for her work in next vision. After use by 15 days of the lenses described, is by contrast material in ophthalmiclenses CR-39 and the prescription, used the same time. By building a refractometer, it was determined the focal length and the index of refraction, obtainingthe number ABBE and reflectance. We measuredpower of posterior index, thickness and density Sagita.Results: with regard to power, the patient is always inclined to choose the nonprescription lenses with greater increases in order to seek magnification, showing that patients are overcorrect, plus signs of the power of these lenses, not accounted for 40 percent of the cases. The average density of the nonprescriptionlenses was 1.18 g/cm3, the index of refraction 1560 and an average number ABBE average of 30.Conclusions: Because of these characteristics lenses are less thick, less weight, more chromatic dispersionthat lenses reference CR-39.

Prismas inducidos por descentraciones ópticasen los lentes de venta libre con el referente delentes oftálmicos y evaluación del confort visualen pacientes présbitas mayores de 40 años / Prisms induced by optical descentrations in the lenses of free sale with reference of ophthalmic lenses and evaluation of the visual comfort in presbyope patients over 40 years

Objetivo: determinar la distancia entre los centros ópticos de los lentes de venta libre con el referente de lentes oftálmicos y evaluar el confort visual.Materiales y métodos: 50 pacientes présbitas usuariosde corrección únicamente para visión próxima. A cada paciente se le realizó un examen optométrico inicial y se le prescribieron inicialmente lentes de venta libre o lupas magnificadoras y posteriormente lentes oftálmicos prescritos. A los 15 días de usar las lupas magnificadoras y al tiempo de usar los lentes oftálmicos de calidad óptica conocida, se realizó un control en el que se otorgó al paciente una encuesta para diligenciar de acuerdo a su experiencia con el tiempo de uso de las lupas y los lentes oftálmicos, con el fin de analizar y comparar posibles síntomas al usar las dos formas de corrección visual y explicandola razón por la cual el paciente tiene dificultades en la adaptación de su prescripción óptica. A todos los lentes se midió el poder, los centros ópticos y a la vez las descentraciones ópticas que generan prismas inducidos en cada uno de los lentes. Se compararon entre sí y con la encuesta para determinar cuál de estos produjo mayor inconfort visual y astenopía.Resultados: se encontró, al comparar las descentracionesy prismas inducidos entre los dos tipos de lentes, una diferencia estadísticamente significativa (p < 0.05) para prisma base externa y prisma base inferior. No se encontraron diferencias estadísticas para prisma base interna entre los grupos comparados.Conclusiones: En este estudio se ratifica que el uso de los lentes de venta libre no cubre de la misma manera la necesidad visual de cada paciente, de dondenace la diferente sintomatología e intolerancia a dichos lentes.

Objectives:Materials and Methods: 50 patients présbitas users only for vision correction next. Each patient is carried out an initial examination optometrists and prescribedinitially lenses or magnifying glasses Magnificoand then prescribed ophthalmic lenses. After 15 days of using the magnificent and magnifying glasses at the time using the optical quality of ophthalmic lenses known, took place controls where the patient was given a survey that diligence according to their experience with the usage time of magnifying glasses and ophthalmic lenses, in order to analyze and comparepossible symptoms when using the two forms of visual correction and explaining why the patient has difficulty in adapting their prescription optics. All lenses were measured power, optical centers and turn off the lenses that generate prisms induced in each of the lenses. Were compared with each other and with the survey to determine which of these visualand produced more uncomfortable astenopia.Results: we found a statistically significant differencewhen comparing the prisms off and induced betweenthe two types of lenses.Conclusions: this study confirms that the use of nonprescription lenses do not cover the same way the visual need of each patient and hence arises the different symptoms and intolerance to such lenses.

Ilusões e desorientações espaciais em vôo / Disorientations and spatial illusions in flight

A velocidade da evolução tecnológica é superior à evolução humana, por isso, o homem encontra-se cada vez mais inserido em ambientes e situações inóspitas que muitas vezes atingem condições inviáveis à vida. A medicina aeroespacial tem como missão avalar as variáveis ambientais, assim como, as respostas fisiológicas relacionado ao vôo atmosférico e espacial.O presente trabalho tem como objetivo, o levantamento das ilusões espaciais mis frequentes, as situações em que podem ocorrer desorientações e os mecanismos adaptativos através de artifícios ou não, tornando ciente ao aeronavegante as possibilidades de desorientação para que ele não seja pego de surpresa.

Ilusöes: o olho mágico da percepçäo / Illusions: a window into perception

A percepçäo é a construçäo ativa de um estado neural que se correlaciona a elementos biologicamente relevantes do ambiente. Esta correlaçäo, longe de estabelecer uma representaçäo fiel do mundo, guia nossas açöes na elaboraçäo de comportamentos adaptativos, sendo, portanto, condicionada por fatores evolutivos. Já que a construçäo de um percepto é um processo intrinsecamente ambíguo, discrepâncias perceptivas podem surgir a partir de condiçöes idênticas de estimulaçäo. Essas discrepâncias säo denominadas ilusöes, e se originam dos mesmos mecanismos fisiológicos que produzem a nossa percepçäo cotidiana. Derivando de diferentes fatores, tais como ópticos, sensoriais e cognitivos, as ilusöes visuais säo instrumentos úteis na exploraçäo das bases fisiológicas da percepçäo e de sua interaçäo com o planejamento e execuçäo de açöes motoras. Aqui, examinamos as origens biológicas das ilusöes visuais e algumas de suas relaçöes com aspectos neurobiológicos, filosóficos e estéticos

Basics of seeing motion

This chapter is about basic conditions of seeing motion (mostly of single objects in the frontoparallel plane. It emphasizes the richness and challenge of phenomena in motion perception. Apart from the distinction between afferent (retinal) and efferent (oculomotor) mechanisms, motion percepts can results from real (object) motion as well as from various forms of apparent motion (stroboscopic or phi motion, induced motion, autokinesis). Further intriguing motion phenomena include motion contrast and assimilation, motion adaptation and after effects, and velocity transposition. Finally, anticipatory performance of motion extrapolation is considered as a dynamic case of a modal perceptual completion, indicating that visual motion is closely related to action.

The rubber square illusion

We report a new illusion of elasticity in a rigid surface. A square frame is presented behind a concentric occluding cross. When the two surfaces are rotated rigidly, the square frame appears ôruberryö, that is, it appears to contract or expand during the rotation. The rubber square illusion is related to a number of other illusory phenomena involving motion and surface stratification. It is generally believed that these phenomena are due to suppression of potentially veridical motion signals at t-junctions signaling occlusions. However, in all previously reported phenomena the effect of t-junctions was confounded with effects due to surface relative motion, spatial integration, or relative contrast. Given that none of these potential confounds applies to our demonstration, the rubber square illusion provides critical evidence that t-junctions are sufficient to cause suppression of the corresponding motion signals.

A combination of focusing and defocusing through yoga reduces optical illusion more than focusing alone.

The degree of optical illusion was assessed using standard Muller-Lyer lines in two groups (yoga and control) of thirty subjects each. All subjects were between eighteen and forty two years of age. The difference between the reading at which the lines were actually equal and the reading at which the subject felt them to be equal, was noted as the degree of illusion ("di"). Each subject was assessed at the beginning and end of a month. During the month the yoga group received training in yoga, while the control group carried on with their usual routine. At the end of the month the yoga group showed a significant (two factor ANOVA, Tukey test, P < .001) decrease in the "di" (86%), whereas the control group showed no change. The improvement following yoga could be attributed to the combination of focusing and defocusing involved in yoga practice, as these factors are known to influence the "di". Previous results which mentioned a 79% decrease in "di" with focusing alone, provided a comparison.

Photodensitometric tracing of mach bands and its significance

Mach bands, a visual phenomenon resulting from lateral inhibitory impulsess in the retina, are recognized aslucent or dense lines at the borders of different radiographic densities. A number of clinical situations have been described in which Mach bands may cause difficulty in radiographic diagnosis. Photodensitometric measurement of the film can differentiate the true change in film density from the Mach band which is an optical illusion. Authors present several examples of photodensitometric tracings of Mach bands, with the brief review of themechanism of their production.