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Attention, Perception & Psychophysics Jan 2022Two experiments tested a prediction derived from the recent finding that the Oppel-Kundt illusion - the overestimation of a filled extent relative to an empty one - was...
Two experiments tested a prediction derived from the recent finding that the Oppel-Kundt illusion - the overestimation of a filled extent relative to an empty one - was much attenuated when the empty part of a bipartite row of dots was vertical and the filled part horizontal, suggesting that the Horizontal-vertical illusion - the overestimation of vertical extents relative to horizontal ones - only acted on the empty part of an Oppel-Kundt figure. Observers had to bimanually indicate the sizes of the two parts of an Oppel-Kundt figure, which were arranged one above the other with one part vertical and the other part tilted -45°, 0°, or 45°. Results conformed to the prediction but response bias was greater when observers had been instructed to point to the extents' endpoints than when instructed to estimate the extents' lengths, suggesting that different concepts and motor programs had been activated.
Topics: Humans; Optical Illusions; Thumb
PubMed: 34341939
DOI: 10.3758/s13414-021-02360-8 -
Perception Jul 2023The Ebbinghaus and Delboeuf illusions affect the perceived size of a target circle depending on the size and proximity of circular inducers or a ring. Converging...
The Ebbinghaus and Delboeuf illusions affect the perceived size of a target circle depending on the size and proximity of circular inducers or a ring. Converging evidence suggests that these illusions are driven by interactions between contours mediated by their cortical distance in primary visual cortex. We tested the effect of cortical distance on these illusions using two methods: First, we manipulated retinal distance between target and inducers in a two-interval forced choice design, finding that targets appeared larger with a closer surround. Next, we predicted that targets presented peripherally should appear larger due to cortical magnification. Hence, we tested the illusion strength when positioning the stimuli at various eccentricities, with results supporting this hypothesis. We calculated estimated cortical distances between illusion elements in each experiment and used these estimates to compare the relationship between cortical distance and illusion strength across our experiments. In a final experiment, we modified the Delboeuf illusion to test whether the influence of the inducers/annuli in this illusion is influenced by an inhibitory surround. We found evidence that an additional outer ring makes targets appear smaller compared to a single-ring condition, suggesting that near and distal contours have antagonistic effects on perceived target size.
Topics: Humans; Illusions; Optical Illusions; Size Perception; Gravitation; Retina
PubMed: 37335155
DOI: 10.1177/03010066231175014 -
Attention, Perception & Psychophysics May 2020Explanations of the Ponzo size illusion, the simultaneous contrast illusion, and the Craik-O'Brien-Cornsweet brightness illusions involve either stimulus-driven...
Explanations of the Ponzo size illusion, the simultaneous contrast illusion, and the Craik-O'Brien-Cornsweet brightness illusions involve either stimulus-driven processes (assimilation, enhanced contrast, and anchoring) or prior experiences. Real-world up-down asymmetries for typical direction of illumination and ground planes in our physical environment should influence these illusions if they are experience based, but not if they are stimulus driven. Results presented here demonstrate differences in illusion strengths between upright and inverted versions of all three illusions. A left-right asymmetry of the Cornsweet illusion was produced by manipulating the direction of illumination, providing further support for the involvement of an experience-based explanation. When the inducers were incompatible with the targets being located at the different distances, the Ponzo illusion persisted and so did the influence from orientation, providing evidence for involvement of processes other than size constancy. As defined here, upright for the brightness illusions is consistent with an interpretation of a shaded bulging surface and a 3D object resulting from a light-from-above assumption triggering compensation for varying illumination. Upright for the Ponzo illusion is consistent with the inducers in the form of converging lines being interpreted as railway tracks receding on the ground triggering size constancy effects. The implications of these results, and other results providing evidence against experience-based accounts of the illusions, are discussed.
Topics: Adult; Aged; Contrast Sensitivity; Female; Form Perception; Humans; Male; Middle Aged; Optical Illusions; Orientation, Spatial; Photic Stimulation; Young Adult
PubMed: 31875317
DOI: 10.3758/s13414-019-01953-8 -
Vision Research Sep 2003The scintillating grid is a recently discovered visual illusion, created by superimposing white discs on the intersections of orthogonal gray bars on a black background....
The scintillating grid is a recently discovered visual illusion, created by superimposing white discs on the intersections of orthogonal gray bars on a black background. Even though the entire display is stationary, observers perceive dark spots appearing and disappearing rapidly within some of the white discs. This scintillation effect is correlated with eye position and eye movements. Here we investigate whether covert shifts of attention, as revealed by cueing and visual search paradigms, can also affect the illusion. We find that the chance of a particular intersection scintillating is directly correlated with distance from the attentional focus, regardless of the location of the fixation point. This suggests that the dynamics of this illusion might reflect the distribution of attention in space and time.
Topics: Analysis of Variance; Attention; Eye Movements; Female; Humans; Male; Optical Illusions; Pattern Recognition, Visual; Photic Stimulation; Visual Acuity
PubMed: 12885373
DOI: 10.1016/s0042-6989(03)00412-7 -
Medicina (Kaunas, Lithuania) 2006In psychophysical experiments, the Delboeuf illusion was measured as a function of spatial parameters of the stimulus pattern. During the experiments, the stimulus... (Comparative Study)
Comparative Study
In psychophysical experiments, the Delboeuf illusion was measured as a function of spatial parameters of the stimulus pattern. During the experiments, the stimulus shape, size, luminance, and the dimensions of inducing surround varied. Subjects were asked to change the size of the test part of the stimulus by adjusting its diameter to value that made the test part appear equal to the perceived size of the referent part. The difference in diameters between the test and referent parts of the stimulus, determined after the perceived equality was achieved, was considered to be the value of the illusion magnitude. The magnitude of the Delboeuf illusion was dependent on the type of the stimuli and their contrast: the filled circles with the luminance contrast yielded stronger illusion than the open circles and the stimuli with isoluminant colors. The magnitude of the illusion did not change noticeably with variations of the luminance of the stimulus, but diminished when the luminance of the stimulus approached the level of isoluminance with the background. The neurophysiological spatial filtering model, applied to the Delboeuf stimuli patterns, has provided computational results similar to the present experimental findings.
Topics: Humans; Light; Models, Theoretical; Optical Illusions; Photic Stimulation; Psychophysics; Size Perception
PubMed: 16963835
DOI: No ID Found -
Vision Research Sep 2008Differences between the geometrical properties of simple configurations and their visual percept are called geometrical-optical illusions. They can be differentiated... (Review)
Review
Differences between the geometrical properties of simple configurations and their visual percept are called geometrical-optical illusions. They can be differentiated from illusions in the brightness or color domains, from ambiguous figures and impossible objects, from trompe l'oeil and perspective drawing with perfectly valid views, and from illusory contours. They were discovered independently by several scientists in a short time span in the 1850's. The clear distinction between object and visual space that they imply allows the question to be raised whether the transformation between the two spaces can be productively investigated in terms of differential geometry and metrical properties. Perceptual insight and psychophysical research prepares the ground for investigation of the neural representation of space but, because visual attributes are processed separately in parallel, one looks in vain for a neural map that is isomorphic with object space or even with individual forms it contains. Geometrical-optical illusions help reveal parsing rules for sensory signals by showing how conflicts are resolved when there is mismatch in the output of the processing modules for various primitives as a perceptual pattern's unitary structure is assembled. They point to a hierarchical ordering of spatial primitives: cardinal directions and explicit contours predominate over oblique orientation and implicit contours (Poggendorff illusion); rectilinearity yields to continuity (Hering illusion), point position and line length to contour orientation (Ponzo). Hence the geometrical-optical illusions show promise as analytical tools in unraveling neural processing in vision.
Topics: Form Perception; Humans; Lighting; Neurons; Optical Illusions; Pattern Recognition, Visual; Psychophysics; Visual Cortex
PubMed: 18606433
DOI: 10.1016/j.visres.2008.05.016 -
Vision Research Jun 2022Converging evidence has demonstrated our remarkable capacities to process individual faces. However, in real-life contexts, we rarely see faces in isolation. It is...
Converging evidence has demonstrated our remarkable capacities to process individual faces. However, in real-life contexts, we rarely see faces in isolation. It is largely unknown how our visual system processes a multitude of faces. The current study explored this question by using the "Fat Face" illusion: when two identical faces are vertically aligned, the bottom face appears bigger. In Experiment 1, we tested the robustness of this illusion by using faces varied by gender and race, by recruiting participants from different countries (Canadian, Chinese, and French), and by implementing different task requirements. We found that the illusion was stable and immune to variations in face gender or face race, perceptual familiarity, and task requirements. Experiment 2 further indicated that binocular vision was essential for this visual illusion. When participants performed the task with one eye covered, the previously robust illusion completely disappeared. Together, these findings revealed a visual adaptation for processing multiple faces in the environment: the face at the top is perceived as more distant from the viewer and appears smaller in size than the face at the bottom. More broadly, overestimating the size of the bottom face may represent a fundamental mechanism for social interactions, ensuring the deployment of attention to those closest to self.
Topics: Canada; Face; Humans; Optical Illusions; Recognition, Psychology; Vision, Binocular
PubMed: 35149376
DOI: 10.1016/j.visres.2022.108015 -
Journal of Vision Jun 2021Mruczek et al. (2015) showed that a moving version of the Ebbinghaus illusion almost doubles in strength compared to the standard version. In their stimulus, the size of...
Mruczek et al. (2015) showed that a moving version of the Ebbinghaus illusion almost doubles in strength compared to the standard version. In their stimulus, the size of the surrounding inducers was modulated between large and small and the whole stimulus was made to drift during the surround modulation. We first replicated the original dynamic Ebbinghaus illusion and then explored dynamic presentations for other simultaneous contrast and geometric illusions. We found no increase in illusion strength in any that we sampled. Here we report the results for the Müller-Lyer illusion and the orientation contrast illusion. Surprisingly, when these two illusions were presented dynamically, their effects were greatly reduced for the Müller-Lyer illusion and eliminated for the orientation contrast illusion.
Topics: Humans; Illusions; Mathematics; Optical Illusions; Size Perception
PubMed: 34110368
DOI: 10.1167/jov.21.6.4 -
BMC Psychology Mar 2024Humans are typically inept at evaluating their abilities and predispositions. People dismiss such a lack of metacognitive insight into their capacities while even...
Humans are typically inept at evaluating their abilities and predispositions. People dismiss such a lack of metacognitive insight into their capacities while even enhancing (albeit illusorily) self-evaluation such that they should have more desirable traits than an average peer. This superiority illusion helps maintain a healthy mental state. However, the scope and range of its influence on broader human behavior, especially perceptual tasks, remain elusive. As belief shapes the way people perceive and recognize, the illusory self-superiority belief potentially regulates our perceptual and metacognitive performance. In this study, we used hierarchical Bayesian estimation and machine learning of signal detection theoretic measures to understand how the superiority illusion influences visual perception and metacognition for the Ponzo illusion. Our results demonstrated that the superiority illusion correlated with the Ponzo illusion magnitude and metacognitive performance. Next, we combined principal component analysis and cross-validated regularized regression (relaxed elastic net) to identify which superiority components contributed to the correlations. We revealed that the "extraversion" superiority dimension tapped into the Ponzo illusion magnitude and metacognitive ability. In contrast, the "honesty-humility" and "neuroticism" dimensions only predicted Ponzo illusion magnitude and metacognitive ability, respectively. These results suggest common and distinct influences of superiority features on perceptual sensitivity and metacognition. Our findings contribute to the accumulating body of evidence indicating that the leverage of superiority illusion is far-reaching, even to visual perception.
Topics: Humans; Metacognition; Optical Illusions; Bayes Theorem; Visual Perception; Diagnostic Self Evaluation
PubMed: 38429795
DOI: 10.1186/s40359-024-01625-9 -
Trends in Cognitive Sciences Dec 2008The motion aftereffect is a robust illusion of visual motion resulting from exposure to a moving pattern. There is a widely accepted explanation of it in terms of... (Review)
Review
The motion aftereffect is a robust illusion of visual motion resulting from exposure to a moving pattern. There is a widely accepted explanation of it in terms of changes in the response of cortical direction-selective neurons. Research has distinguished several variants of the effect. Converging recent evidence from different experimental techniques (psychophysics, single-unit recording, brain imaging, transcranial magnetic stimulation, visual evoked potentials and magnetoencephalography) reveals that adaptation is not confined to one or even two cortical areas, but occurs at multiple levels of processing involved in visual motion analysis. A tentative motion-processing framework is described, based on motion aftereffect research. Recent ideas on the function of adaptation see it as a form of gain control that maximises the efficiency of information transmission at multiple levels of the visual pathway.
Topics: Animals; Brain Mapping; Cerebral Cortex; Evoked Potentials, Visual; Figural Aftereffect; Humans; Magnetic Resonance Imaging; Motion Perception; Nerve Net; Neurons; Optical Illusions; Orientation; Pattern Recognition, Visual; Psychophysics; Transcranial Magnetic Stimulation; Visual Pathways
PubMed: 18951829
DOI: 10.1016/j.tics.2008.09.002