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Scientific Reports Feb 2017When viewing ambiguous stimuli, people tend to perceive some interpretations more frequently than others. Such perceptual biases impose various types of constraints on...
When viewing ambiguous stimuli, people tend to perceive some interpretations more frequently than others. Such perceptual biases impose various types of constraints on visual perception, and accordingly, have been assumed to serve distinct adaptive functions. Here we demonstrated the interaction of two functionally distinct biases in bistable biological motion perception, one regulating perception based on the statistics of the environment - the viewing-from-above (VFA) bias, and the other with the potential to reduce costly errors resulting from perceptual inference - the facing-the-viewer (FTV) bias. When compatible, the two biases reinforced each other to enhance the bias strength and induced less perceptual reversals relative to when they were in conflict. Whereas in the conflicting condition, the biases competed with each other, with the dominant percept varying with visual cues that modulate the two biases separately in opposite directions. Crucially, the way the two biases interact does not depend on the dominant bias at the individual level, and cannot be accounted for by a single bias alone. These findings provide compelling evidence that humans robustly integrate biases with different adaptive functions in visual perception. It may be evolutionarily advantageous to dynamically reweight diverse biases in the sensory context to resolve perceptual ambiguity.
Topics: Bias; Computer Simulation; Depth Perception; Female; Humans; Male; Motion Perception; Visual Perception
PubMed: 28165061
DOI: 10.1038/srep42018 -
Biological Cybernetics 1990In the context of the models of structure from motion visual processing, we propose that the optic-flow field is a source of information for the perception of the...
In the context of the models of structure from motion visual processing, we propose that the optic-flow field is a source of information for the perception of the curvature of a smooth surface in motion. In particular, it is shown how the spin variation (SV), a second spatial derivative of the retinal velocity field, is mathematically related to the curvature of the surface. Under the hypothesis that the visual system relies on SV to analyse the structure of a moving surface, a neural scheme for SV detection is proposed and psychophysical predictions are developed. Results obtained on artificial images show that the SV scheme presents a rather weak sensitivity to noise in conditions of low image velocity.
Topics: Computer Simulation; Models, Neurological; Motion Perception; Visual Perception
PubMed: 2302430
DOI: 10.1007/BF00198096 -
Multisensory Research 2015There is an ongoing debate about whether adult human primary visual cortex (V1) is capable of large-scale cortical reorganization in response to bilateral retinal... (Review)
Review
There is an ongoing debate about whether adult human primary visual cortex (V1) is capable of large-scale cortical reorganization in response to bilateral retinal lesions. Animal models suggest that the visual neural circuitry maintains some plasticity through adulthood, and there are also a few human imaging studies in support this notion. However, the interpretation of these data has been brought into question, because there are factors besides cortical reorganization, such as the presence of sampling bias and/or the unmasking of task-dependent feedback signals from higher level visual areas, that could also explain the results. How reasonable would it be to accept that adult human V1 does not reorganize itself in the face of disease? Here, we discuss new evidence for the hypothesis that adult human V1 is not as capable of reorganization as in animals and juveniles, because in adult humans, cortical reorganization would come with costs that outweigh its benefits. These costs are likely functional and visible in recent experiments on adaptation--a rapid, short-term form of neural plasticity--where they prevent reorganization from being sustained over the long-term.
Topics: Adult; Brain Mapping; Feedback; Humans; Neuronal Plasticity; Visual Cortex; Visual Perception
PubMed: 26288901
DOI: 10.1163/22134808-00002496 -
Perception 2001
Topics: Cues; Humans; Perceptual Distortion; Psychophysics; Vision, Binocular; Visual Perception
PubMed: 11257973
DOI: 10.1068/p3001ed -
Current Biology : CB Aug 2009Gaze perception has been thought to be stimulus-driven. This view is challenged by a new demonstration that a gaze direction aftereffect can be influenced by beliefs... (Review)
Review
Gaze perception has been thought to be stimulus-driven. This view is challenged by a new demonstration that a gaze direction aftereffect can be influenced by beliefs about the gazer's ability to see.
Topics: Figural Aftereffect; Fixation, Ocular; Humans; Social Perception; Visual Perception
PubMed: 19674548
DOI: 10.1016/j.cub.2009.06.016 -
Shinrigaku Kenkyu : the Japanese... Apr 2007The present study aims to examine whether depth perception based on pictorial cues in the peripheral visual field is improved by compensating for the peripheral...
The present study aims to examine whether depth perception based on pictorial cues in the peripheral visual field is improved by compensating for the peripheral reduction of visual sensitivity. Figures that partially overlapped or had apparent transparency over a background figure were presented on a CRT monitor at the central-peripheral retinal regions of 2.5-10 degrees eccentricity under the two conditions of same size or size adjusted for the Cortical Magnification Scale (Virsu & Rovamo, 1979). In Experiment 1 the subjects could discriminate the depth relationship of two cortically magnified figures when these were presented within the retinal eccentricity of 10 degrees, even when solutions for the tasks were not dependent on a single visual attribute (brightness, shape). But discrimination in the peripheral visual field became difficult when the number of visual attributes of the stimuli increased (Experiment 2). We conclude that even for peripheral vision, depth perception based on pictorial cues is possible when cortically magnified stimuli are used. However, it should be further study whether or not the visual acuity is an only determinant for the difference between central and peripheral depth perception.
Topics: Adult; Cues; Depth Perception; Humans; Visual Acuity; Visual Fields; Visual Perception
PubMed: 17511247
DOI: 10.4992/jjpsy.78.51 -
Scientific American Feb 1983Isoluminant stimulus is an image whose edges are defined only by a change in color, not by change in brightness. The stimulus here is imperfect: the blue parts and the...
Isoluminant stimulus is an image whose edges are defined only by a change in color, not by change in brightness. The stimulus here is imperfect: the blue parts and the green parts of the image are only as nearly equal in brightness as they can be on the printed page. Moreover, the change in brightness beyond the edge of the page is apparent, and so is the fact that the reader is holding the magazine at reading distance. When such cues are removed under laboratory conditions, subjects faced with an isoluminant stimulus prove unable to bring its edges into focus. This deficiency contributes to making a familiar face hard to recognize. The experiment indicates that the brain process underlying visual accommodation (the focusing of the eyes) cannot "see" color; it is a hidden process distinct from the processes that lead to perception. The image shows Groucho Marx as he appeared in the motion picture Horse Feathers.
Topics: Color Perception; Humans; Motion Perception; Ocular Physiological Phenomena; Vision, Ocular; Visual Perception
PubMed: 6836258
DOI: 10.1038/scientificamerican0283-94 -
Neurological Sciences : Official... Dec 2009Visual aura is the most common feature associated with migraine, though it can occur separately. In both cases it often represents a dramatic event, especially for... (Review)
Review
Visual aura is the most common feature associated with migraine, though it can occur separately. In both cases it often represents a dramatic event, especially for patients who experience it for the first time. Besides, its subjective characteristics may illuminate on the functional architecture of the visual cortex. Repetitive events of migraine and visual aura have been suggested to affect the visual system in the long run, both on the cortical and precortical level. In effect, objective investigation of visual functions in patients support the idea that a selective damage does occur, so that more attention to visual examination seems to be justified. In this paper, subjective and psychophysical aspects of visual aura are examined, lastly highlighting and discussing the interesting correlations found between this condition and normal-tension glaucoma.
Topics: Brain; Humans; Migraine with Aura; Visual Perception
PubMed: 19779857
DOI: 10.1007/s10072-009-0137-4 -
Nature Mar 1979
Topics: Humans; Motion Perception; Visual Pathways; Visual Perception
PubMed: 763367
DOI: 10.1038/278192a0 -
Neural Networks : the Official Journal... Jul 2015Although numerous models describe the individual neural mechanisms that may be involved in the perception of visual motion, few of them have been constructed to take...
Although numerous models describe the individual neural mechanisms that may be involved in the perception of visual motion, few of them have been constructed to take arbitrary stimuli and map them to a motion percept. Here, we propose an integrated dynamical motion model (IDM), which is sufficiently general to handle diverse moving stimuli, yet sufficiently precise to account for a wide-ranging set of empirical observations made on a family of random dot kinematograms. In particular, we constructed models of the cortical areas involved in motion detection, motion integration and perceptual decision. We analyzed their parameters through dynamical simulations and numerical continuation to constrain their proper ranges. Then, empirical data from a family of random dot kinematograms experiments with systematically varying direction distribution, presentation duration and stimulus size, were used to evaluate our model and estimate corresponding model parameters. The resulting model provides an excellent account of a demanding set of parametrically varied behavioral effects on motion perception, providing both quantitative and qualitative elements of evaluation.
Topics: Algorithms; Humans; Models, Neurological; Motion; Motion Perception; Visual Fields; Visual Perception
PubMed: 25897511
DOI: 10.1016/j.neunet.2015.03.011