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Current Biology : CB Mar 2022Recent research has uncovered a surprising new role of colour in the perception of three-dimensional shape. The brain is exquisitely sensitive to visual patterns...
Recent research has uncovered a surprising new role of colour in the perception of three-dimensional shape. The brain is exquisitely sensitive to visual patterns emerging from the way different wavelengths interact with surfaces.
Topics: Brain; Color Perception; Visual Perception
PubMed: 35349812
DOI: 10.1016/j.cub.2022.01.077 -
Current Biology : CB Dec 2022Eye movements cause rapid motion of the retinal image, potentially confusable with external motion. A recent study shows that neurons in mouse primary visual cortex...
Eye movements cause rapid motion of the retinal image, potentially confusable with external motion. A recent study shows that neurons in mouse primary visual cortex distinguish self-generated from external motion by combining sensory input with saccade-related signals from the thalamic pulvinar nucleus.
Topics: Animals; Mice; Eye Movements; Saccades; Neurons; Perception; Motion Perception; Photic Stimulation; Visual Perception
PubMed: 36538882
DOI: 10.1016/j.cub.2022.11.003 -
Vision Research Nov 2007The lightness of a visual surface is its perceived achromatic reflectance [Adelson, E. H., (2000). Lightness perception and lightness illusions. In M. Gazzaniga (Ed.),... (Review)
Review
The lightness of a visual surface is its perceived achromatic reflectance [Adelson, E. H., (2000). Lightness perception and lightness illusions. In M. Gazzaniga (Ed.), The new cognitive neuroscience (2nd ed.) (pp. 339-351) Berlin: Springer; Gilchrist, A. (1999). Lightness perception. In R. W. F. Keil (Ed.), MIT encyclopedia of cognitive science (pp. 471-472). Cambridge: MIT press]. Lightness ranges from black, through various shades of grey, up to white. Anderson and Winawer [Anderson, B., Winawer, J. (2005). Image segmentation and lightness perception. Nature, 434, 79-83] suggested that perceptual decomposition of image luminance into multiple sources in different layers (e.g., perceptual transparency) is critical to the their lightness illusions. However, I show that simple perceptual occlusion evoked by T-junctions will work as well, suggesting that perceptual scission of luminance into multiple layers is unnecessary for such effects. I argue that the lightness illusions presented by Anderson and Winawer involve fundamentally different mechanisms than previously studied lightness illusions, including those involving perceptual transparency.
Topics: Algorithms; Contrast Sensitivity; Humans; Lighting; Optical Illusions; Pattern Recognition, Visual; Perceptual Masking; Scattering, Radiation; Visual Perception
PubMed: 17949774
DOI: 10.1016/j.visres.2007.06.004 -
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 -
Physiological Reports Nov 2023The purpose of the current study was to clarify the effect of eccentricity on visual motion prediction using a time-to-contact (TTC) task. TTC indicates the predictive...
The purpose of the current study was to clarify the effect of eccentricity on visual motion prediction using a time-to-contact (TTC) task. TTC indicates the predictive ability to accurately estimate the time-to-contact of a moving object based on visual motion perception. We also measured motion reaction time (motion RT) as an indicator of the speed of visual motion perception. The TTC task was to press a button when the moving target would arrive at the stationary goal. In the occluded condition, the target dot was occluded 500 ms before the time to contact. The motion RT task was to press a button as soon as the target moved. The visual targets were randomly presented at five different eccentricities (4°, 6°, 8°, 10°, 12°) and moved on a circular trajectory at a constant tangent velocity (8°/s) to keep the eccentricity constant. Our results showed that TTC in the occluded condition showed an earlier response as the eccentricity increased. Furthermore, the motion RT became longer as the eccentricity increased. Therefore, it is most likely that a slower speed perception in peripheral vision delays the perceived speed of motion onset and leads to an earlier response in the TTC task.
Topics: Visual Perception; Motion Perception; Vision, Ocular; Reaction Time; Motion
PubMed: 37985195
DOI: 10.14814/phy2.15877 -
Current Biology : CB Jun 2017How does our brain use differences between the images in our two eyes, binocular disparities, to generate depth perception? New work shows that a type of neural network...
How does our brain use differences between the images in our two eyes, binocular disparities, to generate depth perception? New work shows that a type of neural network trained on natural binocular images can learn parameters that match key properties of visual cortex. Most information is conveyed by cells which sense differences between the two eyes' images.
Topics: Depth Perception; Vision Disparity; Vision, Binocular; Visual Cortex; Visual Perception
PubMed: 28633028
DOI: 10.1016/j.cub.2017.05.013 -
Proceedings of the National Academy of... May 2003Visual stimuli may remain invisible but nevertheless produce strong and reliable effects on subsequent actions. How well features of a masked prime are perceived depends...
Visual stimuli may remain invisible but nevertheless produce strong and reliable effects on subsequent actions. How well features of a masked prime are perceived depends crucially on its physical parameters and those of the mask. We manipulated the visibility of masked stimuli and contrasted it with their influence on the speed of motor actions, comparing the temporal dynamics of visual awareness in metacontrast masking with that of action priming under the same conditions. We observed priming with identical time course for reportable and invisible prime stimuli, despite qualitative changes in the masking time course. Our findings indicate that experimental variations that modify the subjective visual experience of masked stimuli have no effect on motor effects of those stimuli in early processing. We propose a model that provides a quantitative account of priming effects on response speed and accuracy.
Topics: Adult; Brain; Choice Behavior; Functional Laterality; Humans; Pattern Recognition, Visual; Reaction Time; Visual Perception
PubMed: 12719543
DOI: 10.1073/pnas.0931489100 -
Journal of Vision Oct 2016Perception is shaped not only by current sensory inputs but also by expectations generated from past sensory experience. Humans viewing ambiguous stimuli in a stable...
Perception is shaped not only by current sensory inputs but also by expectations generated from past sensory experience. Humans viewing ambiguous stimuli in a stable visual environment are generally more likely to see the perceptual interpretation that matches their expectations, but it is less clear how expectations affect perception when the environment is changing predictably. We used statistical learning to teach observers arbitrary sequences of natural images and employed binocular rivalry to measure perceptual selection as a function of predictive context. In contrast to previous demonstrations of preferential selection of predicted images for conscious awareness, we found that recently acquired sequence predictions biased perceptual selection toward unexpected natural images and image categories. These perceptual biases were not associated with explicit recall of the learned image sequences. Our results show that exposure to arbitrary sequential structure in the environment impacts subsequent visual perceptual selection and awareness. Specifically, for natural image sequences, the visual system prioritizes what is surprising, or statistically informative, over what is expected, or statistically likely.
Topics: Adolescent; Adult; Awareness; Biometry; Female; Humans; Male; Perceptual Masking; Vision Disparity; Vision, Binocular; Visual Perception; Young Adult
PubMed: 27802512
DOI: 10.1167/16.13.6 -
PloS One 2018Behavioral tests have been extensively used to measure the visual function of mice. To determine how precisely mice perceive certain visual cues, it is necessary to have...
Behavioral tests have been extensively used to measure the visual function of mice. To determine how precisely mice perceive certain visual cues, it is necessary to have a quantifiable measurement of their behavioral responses. Recently, virtual reality tests have been utilized for a variety of purposes, from analyzing hippocampal cell functionality to identifying visual acuity. Despite the widespread use of these tests, the training requirement for the recognition of a variety of different visual targets, and the performance of the behavioral tests has not been thoroughly characterized. We have developed a virtual reality behavior testing approach that can essay a variety of different aspects of visual perception, including color/luminance and motion detection. When tested for the ability to detect a color/luminance target or a moving target, mice were able to discern the designated target after 9 days of continuous training. However, the quality of their performance is significantly affected by the complexity of the visual target, and their ability to navigate on a spherical treadmill. Importantly, mice retained memory of their visual recognition for at least three weeks after the end of their behavioral training.
Topics: Animals; Behavior, Animal; Color Perception; Cues; Hippocampus; Memory; Mice; Mice, Inbred C57BL; Motion Perception; Virtual Reality; Visual Perception
PubMed: 29768429
DOI: 10.1371/journal.pone.0196563 -
Vision Research Dec 2015It is well known that visible luminance gradients may generate contrast effects. In this work we present a new paradoxical illusion in which the luminance range of...
It is well known that visible luminance gradients may generate contrast effects. In this work we present a new paradoxical illusion in which the luminance range of gradual transitions has been reduced to make them invisible. By adopting the phenomenological method proposed by Kanizsa, we have found that unnoticeable luminance gradients still generate contrast effects. But, most interestingly, we have found that when their width is narrowed, rather than generating contrast effects on the surrounded surfaces, they generate an assimilation effect. Both high- and low-level interpretations of this "phantom" illusion are critically evaluated.
Topics: Contrast Sensitivity; Humans; Optical Illusions; Phantoms, Imaging; Visual Perception
PubMed: 26505683
DOI: 10.1016/j.visres.2015.10.007