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Vision Research Jan 2023One of the original Ponzo illusion figures, which consists of two converging lines between which two parallel lines of similar length have been inserted orthogonal to...
One of the original Ponzo illusion figures, which consists of two converging lines between which two parallel lines of similar length have been inserted orthogonal to the figure's axis of mirror symmetry, was itself mirror-reflected so that the overall shape of the figure became "< >" or "> <", and one line at a time was inserted into each half. The usual illusion - the overestimation of the length of a line that is nearer to a vertex than a farther-away comparison line - occurred. Experiments 1 and 2 used different distances of target and comparison lines to the vertices, but identical distances of these lines from the converging lines, and so, as a tandem, deconfounded the two variables. Experiments 3 and 4 changed the symmetries of the modified Ponzo figure by reducing opposing half-angles of the converging lines or by tilting target and comparison lines concordantly or discordantly. The first measure, which created unequal distances of the endpoints of the target and comparison lines from the converging lines, hardly affected the amount of illusion. The second measure often attenuated the illusion - equally so for concordant and discordant tilts - suggesting that global and local symmetries of the stimuli, and their accordance, were less important than the vertical versus oblique orientation of target and comparison lines. Descriptively, the main cause of the Ponzo illusion seems to be the size of the gap between target and converging lines. The neural substrate of the effect may be interactions between orientation-sensitive and end-inhibited neurons.
Topics: Humans; Illusions; Optical Illusions; Neurons
PubMed: 36347085
DOI: 10.1016/j.visres.2022.108143 -
Learning & Behavior Mar 2023Survival often depends on the ability of the visual system to process information accurately; thus, research demonstrating that a brain is susceptible to optical...
Survival often depends on the ability of the visual system to process information accurately; thus, research demonstrating that a brain is susceptible to optical illusions is of considerable interest, particularly when the experiments involve phylogenetic comparisons. Are Lõoke et al.'s (Anim. Cogn, 25:43-51, 2022) data strong enough to allow the inclusion of dogs on the list of nonhumans that can perceive illusory Kanizsa figures?
Topics: Animals; Dogs; Phylogeny; Form Perception; Photic Stimulation; Optical Illusions; Brain
PubMed: 36344751
DOI: 10.3758/s13420-022-00551-3 -
Journal of Comparative Psychology... May 2023It has been argued that humans' susceptibility to visual illusions does not simply reflect cognitive flaws but rather specific functional adaptations of our perceptual...
It has been argued that humans' susceptibility to visual illusions does not simply reflect cognitive flaws but rather specific functional adaptations of our perceptual system. The data on cross-cultural differences in the perception of geometric illusions seemingly support this explanation. Little is known, however, about the developmental trajectories of such adaptations in humans, let alone a conclusive picture of the illusionary susceptibility in other primate species. So far, most developmental or comparative studies have tested single illusions with varying procedural implementations. The current study aims at overcoming these limitations by testing human subjects of four different age classes (3- to 5 year-old children and adults) and five nonhuman primate species (capuchin monkeys, bonobos, chimpanzees, gorillas, and orangutans) with an identical setup in five well-known geometric illusions (horizontal-vertical, Ebbinghaus, Mueller-Lyer, Ponzo, and Sander). Two food items of identical size were presented on separate trays with surrounding paintings eliciting the illusion of size differences and subjects were required to choose one of the items. Four of the five illusions elicited a strong effect in adult humans, and older children showed a greater susceptibility to illusions than younger ones. In contrast, only two illusions (Ebbingaus and horizontal-vertical) elicited a mild effect on nonhuman primates with high variation within species and little variation between species. Our results suggests that humans learn to see illusions as they develop during childhood. They also suggest that future work should address how nonhuman primates' experience of these illusion changes throughout their development. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
Topics: Adult; Child; Animals; Humans; Adolescent; Child, Preschool; Illusions; Gorilla gorilla; Pongo; Sapajus; Size Perception; Hominidae; Pan troglodytes; Pan paniscus; Cebus; Pongo pygmaeus; Optical Illusions
PubMed: 36315634
DOI: 10.1037/com0000326 -
Attention, Perception & Psychophysics Jan 2023In the present study, we tested the applicability of the computational model of the illusion of interrupted spatial extent (Bulatov, Marma, & Bulatova, Attention,...
In the present study, we tested the applicability of the computational model of the illusion of interrupted spatial extent (Bulatov, Marma, & Bulatova, Attention, Perception, & Psychophysics, 82, 2714-2727, 2020) to account for the psychophysical data collected with three-dot stimuli containing a cross-shaped contextual distractor. In different series of experiments, the illusion magnitude changes caused by the rotation of distractors with different values of the internal angle (45°, 75°, and 90°) were quantitatively determined. It was shown that the data obtained for all modifications of stimuli can be rather well approximated by model functions proportional to the sum of the absolute values of cosines. A good agreement between theoretical calculations and experimental results supports the suggestion that the perceptual displacement of the stimulus terminators, which occurs due to the processes of local integration of neural activity, may be one of the main causes of the illusion investigated.
Topics: Humans; Optical Illusions; Rotation; Judgment; Photic Stimulation; Psychophysics
PubMed: 36307748
DOI: 10.3758/s13414-022-02596-y -
Behavioural Brain Research Feb 2023Schizophrenic patients show perceptual deficits, which may be detected in visual illusion tasks. Previous studies found that chronic patients show increased sensitivity...
Schizophrenic patients show perceptual deficits, which may be detected in visual illusion tasks. Previous studies found that chronic patients show increased sensitivity to Müller-Lyer illusion as the disorder progresses, although there are a few conflicting reports in the scientific literature. To address these issues, moderate and chronic schizophrenic patients were tested on the Brentano version of the Müller-Lyer illusion task. Their performance was compared to first-degree relatives and unrelated matched controls. Chronic patients showed increased susceptibility to the illusion. Performance on the visual illusion task was not correlated to the number of years since disease onset, medication or (Positive and Negative Syndrome Scale) PANSS scores. The lack of association between illusion sensitivity and PANSS score may reflect the absence of the perceptual dimension in this scale. Based on these results, we suggest that susceptibility to the Müller-Lyer illusion is associated with the stage of schizophrenia rather than disease length.
Topics: Humans; Illusions; Schizophrenia; Optical Illusions
PubMed: 36283565
DOI: 10.1016/j.bbr.2022.114173 -
Case Reports in Dentistry 2022Recently, improvement of appearance and a quest for beauty have become a primary concern for patients. It is a challenging task for a clinician to achieve esthetic...
Recently, improvement of appearance and a quest for beauty have become a primary concern for patients. It is a challenging task for a clinician to achieve esthetic integration of prosthetic pieces for anterior teeth, particularly for highly demanding patients who give attention to particular details. The challenge is harder when only one tooth has to be restored. The objective is to achieve a fully and perfectly integrated rehabilitation with natural dentition. Poorly described, facial line angles are key to the success of achieving the desired tooth shape, especially for the maxillary central incisor. They influence both the shape and color of the tooth through optical illusion. Their misplacement could certainly spoil the esthetic outcome. Thus, it is mandatory to respect and recreate them. The objective of the present study was to define and then to highlight their importance. It also aimed to give some tips on how to perfect the shape of prosthetic teeth through a clinical case of central incisor esthetic rehabilitation.
PubMed: 36276236
DOI: 10.1155/2022/4917536 -
Optics Express Jul 2022Pepper's ghost optical illusion, used in amusement parks, theaters, movies, museums, and other venues since 1862, is produced by reflected light and is often wrongly...
Pepper's ghost optical illusion, used in amusement parks, theaters, movies, museums, and other venues since 1862, is produced by reflected light and is often wrongly described as holographic. This paper presents an alternative illusion technique based on the use of full-color analog Denisyuk holograms mixed with real elements with the help of special lighting. The result is a stunning applied-science experiment that arouses the curiosity of even the most discerning observer, first by combining the real-world and holography on a level never before achieved, and then by creating an unexpected final effect of disappearance.
PubMed: 36236922
DOI: 10.1364/OE.465247 -
International Journal of Retina and... Sep 2022Scanning laser ophthalmoscopes (SLOs) are used widely for reflectance, fluorescence or autofluorescence photography and less commonly for retroillumination imaging. SLOs... (Review)
Review
Scanning laser ophthalmoscopes (SLOs) are used widely for reflectance, fluorescence or autofluorescence photography and less commonly for retroillumination imaging. SLOs scan a visible light or near-infrared radiation laser beam across the retina, collecting light from each retinal spot as it's illuminated. An SLO's clinical applications, image contrast and axial resolution are largely determined by an aperture overlying its photodetector. High contrast, reflectance images are produced using small diameter, centered apertures (confocal apertures) that collect retroreflections and reject side-scattered veiling light returned from the fundus. Retroillumination images are acquired with annular on-axis or laterally-displaced off-axis apertures that capture scattered light and reject the retroreflected light used for reflectance imaging. SLO axial resolution is roughly 300 μm, comparable to macular thickness, so SLOs cannot provide the depth-resolved chorioretinal information obtainable with optical coherence tomography's (OCT's) 3 μm axial resolution. Retroillumination highlights and shades the boundaries of chorioretinal tissues and abnormalities, facilitating detection of small drusen, subretinal drusenoid deposits and subthreshold laser lesions. It also facilitates screening for large-area chorioretinal irregularities not readily identified with other en face retinal imaging modalities. Shaded boundaries create the perception of lesion elevation or depression, a characteristic of retroillumination but not reflectance SLO images. These illusions are not reliable representations of three-dimensional chorioretinal anatomy and they differ from objective OCT en face topography. SLO retroillumination has been a useful but not indispensable retinal imaging modality for over 30 years. Continuing investigation is needed to determine its most appropriate clinical roles in multimodal retinal imaging.
PubMed: 36180893
DOI: 10.1186/s40942-022-00421-0 -
Sexuality & Culture 2023Susan Sontag, in her classic 1967 essay, "The Pornographic Imagination," argued: "Tamed as it may be, sexuality remains one of the demonic forces in human consciousness...
Susan Sontag, in her classic 1967 essay, "The Pornographic Imagination," argued: "Tamed as it may be, sexuality remains one of the demonic forces in human consciousness …. "In the last half-century, Sontag's demonic force of sexuality has transformed pornography and the "pornographic imagination"-let along social relations between women and men. In this essay, I adopt Walter Benjamin's concept of phantasmagoria-a magic-lantern show of optical illusions, rapidly changing size and blending into one another-as the metaphoric commodity form of postmodern capitalist society, fetishism-on-display. I examine the evolution of technological forms of pornographic representation over the last two centuries, including the magiclantern, daguerreotype, photography, stereoscope and film as well as the internet, erotic toys, electronic devises, VR and sex robots. These developments are set against a background of equally profound legal and cultural developments that have recast the sexuality of postmodern America. I argue that these (and other) developments have recast patriarchy and, in some important ways, the sexual relations between "consenting" adults. I conclude reflecting on the current intellectual and political debate about pornography between "pro-sex" and "anti-sex" feminists. With the enormous increase in the production and availability of pornography, I ask, perhaps "quantity" can give way to improved "quality"? I ask whether today's sexual phantasmagoria can fashion a "new" feminist sexuality-and a more humane pornography?
PubMed: 36157715
DOI: 10.1007/s12119-022-10011-9 -
Scientific Reports Sep 2022Spatial planning and development use various visualisation methods. Technological advancements in visualisation techniques have allowed imaging to shift from 2 to 3D...
Spatial planning and development use various visualisation methods. Technological advancements in visualisation techniques have allowed imaging to shift from 2 to 3D dimensions. 3D optical illusion, which converts information recorded in the digital form into a three-dimensional presentation, can be a new tool for presenting spatial development solutions. Since a optical illusion is a direct spatial presentation, it requires neither specialist preparation nor spatial imagination. For this reason, it can become an effective means of visual communication with the public in the area of spatial planning and development. This article shows an example of the imaging of a model element of spatial development (a building) using the 3D illusion technique. Collected opinions of the test group of viewers confirm the usefulness of this tool. The presented 3D visualisation effect evoked positive reactions among the viewers. The use of the hologram technique in spatial planning and development appears to be justified and is an interesting research trend.
PubMed: 36130992
DOI: 10.1038/s41598-022-20173-z