Search results for " illusion"
showing 10 items of 59 documents
The ⊥-Illusion Is Not a T-Illusion
2020
Variants of the capital Latin letter T were prepared with the straight strokes replaced by J-, C-, or S-curves, mimicking handwritten Ts. These were used to test the hypothesis that the overestimation of the length of the T&rsquo
On the interpretation of optical illusions.
1973
If excited by stimuli adjacent in space and time, the optical system frequently perceives illusions in the form of apparent movements. These effects may be attributed to the dynamic properties of the retinal nerve nets. On the basis of a specific psychophysical experiment the mechanism underlying the generation of optical illusions is interpreted by the methods of systems theory and its use in systems analysis is discussed. It is shown that for the perception of apparent movements the transit times of the signals in the dendrites are particularly important.
Strumenti per lo studio della pittura di illusione in Sicilia: il trattato di Paolo Amato e un metodo per l'analisi grafica tridimensionale di una qu…
2006
Oggetto dello studio è la definizione di un metodo per l’analisi grafica tridimensionale di una pittura d’illusione; campo di applicazione è lo studio quadrature nel coro della chiesa di Santa Maria dell’Ammiraglio a Palermo, eseguite da un allievo di Paolo Amato, architetto del Senato palermitano ed autore di un interessante trattato sulla Prospettiva. Il rilievo topografico e fotogrammetrico della volta del coro hanno condotto alla definizione di un modello tridimensionale texturizzato del manufatto, che ha consentito di indagare in modo puntuale la struttura proiettiva delle scene dipinte e le relazioni tra le tecniche di rappresentazione utilizzate e le regole delineate da Amato nel suo…
Intergovernmental Fiscal Relations: The Efficiency Effect of Taxes, Transfers, and Fiscal Illusion
2012
The purpose of this paper is to evaluate the efficiency cost of transfers. To this end, we develop a model of individual demand decisions about the provision of a regional public good that encompasses a continuum of tax–transfer scenarios to finance regional public expenditure. We assume that individuals have identical quasi-linear preferences defined over private consumption and the regional public good, that endowment income varies between individuals and regions, and that regions have different predetermined sizes. In an economy-wide resource constrained framework we show that, despite its simplicity, this model is capable of discriminating the efficiency properties of the different scen…
Introduzione a Vitaliano Brancati, Tutti i racconti, a cura di Domenica Perrone
2018
La raccolta di "Tutti racconti "di Brancati consente di ripercorrere, attraverso la narrativa breve , l'intera parabola intellettuale dell'autore del "Don Giovanni in Sicilia". Dal laboratorio giovanile fino alla disincantata analisi dell'IItalia del dopoguerra. Si offre al lettore così un'avventura letteraria alimentata da una costante tensione morale che si coniuga, spesso attraverso una fine ironia, con il rilievo esistenziale.
White Noise Speech Illusions: A Trait-Dependent Risk Marker for Psychotic Disorder?
2019
Supported by the European Community’s Seventh Framework Program under grant agreement No. HEALTH-F2-2009-241909 (Project EU-GEI)
Cortical excitability changes in chronic migraine vs episodic migraine: evidence by sound-induced flash illusions
2014
Introduction: Sound-induced flash illusions(SIFI) permit to evaluate crossmodal audio-visual perception. When one flash is accompanied by two beeps, it is perceived as two flashes(’fission’illusion); a ‘fusion’ illusion occurs when a single beep causes the fusion of a double flash stimulus. SIFI strictly depends on cortical excitability: healthy controls perceive less illusions by increasing visual cortex excitability through anodal tDCS [1]. Aim: to evaluate if, due to cortical hyperexcitability, differences in SIFI occur in migraine and further changes can be found across migraine cycle, migraine chronification an drug overuse. Methods: we enrolled 64 patients with episodic migraine, 32 w…
Paradox lost: variable colour-pattern geometry is associated with differences in movement in aposematic frogs
2014
Aposematic signal variation is a paradox: predators are better at learning and retaining the association between conspicuousness and unprofitability when signal variation is low. Movement patterns and variable colour patterns are linked in non-aposematic species: striped patterns generate illusions of altered speed and direction when moving linearly, affecting predators' tracking ability; blotched patterns benefit instead from unpredictable pauses and random movement. We tested whether the extensive colour-pattern variation in an aposematic frog is linked to movement, and found that individuals moving directionally and faster have more elongated patterns than individuals moving randomly and…
Perception of illusory surfaces and contours in goldfish
2007
Goldfish(Carassius auratus)were trained to discriminate triangles and squares using a two choice procedure. In the first experiment, three goldfish were trained with food reward on a black outline triangle on a white background, while a black outline square was shown for comparison. In transfer tests, a Kanizsa triangle and a Kanizsa square were presented, perceived by humans as an illusory triangle- or square-shaped surface of slightly higher brightness than the background. The choice behavior in this situation indicates that goldfish are able to discriminate between both figures in almost the same way as in the training situation. In control experiments goldfish did not discriminate betwe…
A Fuzzy Approach to the Role of Symmetry in Shape Formation: The Illusion of the Scalene Triangle
2009
The main purposes of this work are to demonstrate the role of directional symmetry as a second order principle that polarizes the perception of the shape and to show how this preference can be easily encoded in an algorithm using a fuzzy operator for symmetry detection. The role of grouping in influencing shape perception and the role of directional symmetry was demonstrated through small triangles that create a large triangle. The specific questions answered in the psychophysical experiments were the following: Can the grouping by similarity influence both the pointing and the shape of the small and the large isosceles triangles? Conversely, can the shape of the large triangle influence th…