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Journal of Neurophysiology Nov 2022Self-motion through an environment induces various sensory signals, i.e., visual, vestibular, auditory, or tactile. Numerous studies have investigated the role of visual...
Self-motion through an environment induces various sensory signals, i.e., visual, vestibular, auditory, or tactile. Numerous studies have investigated the role of visual and vestibular stimulation for the perception of self-motion direction (heading). Here, we investigated the rarely considered interaction of visual and tactile stimuli in heading perception. Participants were presented optic flow simulating forward self-motion across a horizontal ground plane (visual), airflow toward the participants' forehead (tactile), or both. In separate blocks of trials, participants indicated perceived heading from unimodal visual or tactile or bimodal sensory signals. In bimodal trials, presented headings were either spatially congruent or incongruent with a maximum offset between visual and tactile heading of 30°. To investigate the reference frame in which visuo-tactile heading is encoded, we varied head and eye orientation during presentation of the stimuli. Visual and tactile stimuli were designed to achieve comparable precision of heading reports between modalities. Nevertheless, in bimodal trials heading perception was dominated by the visual stimulus. A change of head orientation had no significant effect on perceived heading, whereas, surprisingly, a change in eye orientation affected tactile heading perception. Overall, we conclude that tactile flow is more important to heading perception than previously thought. We investigated heading perception from visual-only (optic flow), tactile-only (tactile flow), or bimodal self-motion stimuli in different conditions varying in head and eye position. Overall, heading perception was body or world centered and non-Bayes optimal and revealed a centripetal bias. Although being visually dominated, tactile flow revealed a significant influence during bimodal heading perception.
Topics: Humans; Motion Perception; Optic Flow; Vestibule, Labyrinth; Touch Perception; Touch; Photic Stimulation; Visual Perception
PubMed: 36259667
DOI: 10.1152/jn.00231.2022 -
Psychological Science Jan 2017Vision in the fovea, the center of the visual field, is much more accurate and detailed than vision in the periphery. This is not in line with the rich phenomenology of...
Vision in the fovea, the center of the visual field, is much more accurate and detailed than vision in the periphery. This is not in line with the rich phenomenology of peripheral vision. Here, we investigated a visual illusion that shows that detailed peripheral visual experience is partially based on a reconstruction of reality. Participants fixated on the center of a visual display in which central stimuli differed from peripheral stimuli. Over time, participants perceived that the peripheral stimuli changed to match the central stimuli, so that the display seemed uniform. We showed that a wide range of visual features, including shape, orientation, motion, luminance, pattern, and identity, are susceptible to this uniformity illusion. We argue that the uniformity illusion is the result of a reconstruction of sparse visual information (from the periphery) based on more readily available detailed visual information (from the fovea), which gives rise to a rich, but illusory, experience of peripheral vision.
Topics: Adult; Female; Fovea Centralis; Humans; Illusions; Male; Motion; Motion Perception; Orientation; Pattern Recognition, Visual; Photic Stimulation; Reaction Time; Visual Fields; Visual Perception
PubMed: 28078975
DOI: 10.1177/0956797616672270 -
Annual Review of Vision Science Sep 2017Under typical viewing conditions, human observers effortlessly recognize materials and infer their physical, functional, and multisensory properties at a glance. Without... (Review)
Review
Under typical viewing conditions, human observers effortlessly recognize materials and infer their physical, functional, and multisensory properties at a glance. Without touching materials, we can usually tell whether they would feel hard or soft, rough or smooth, wet or dry. We have vivid visual intuitions about how deformable materials like liquids or textiles respond to external forces and how surfaces like chrome, wax, or leather change appearance when formed into different shapes or viewed under different lighting. These achievements are impressive because the retinal image results from complex optical interactions between lighting, shape, and material, which cannot easily be disentangled. Here I argue that because of the diversity, mutability, and complexity of materials, they pose enormous challenges to vision science: What is material appearance, and how do we measure it? How are material properties estimated and represented? Resolving these questions causes us to scrutinize the basic assumptions of mid-level vision.
Topics: Cues; Form Perception; Humans; Lighting; Recognition, Psychology; Surface Properties; Vision, Binocular; Visual Perception
PubMed: 28697677
DOI: 10.1146/annurev-vision-102016-061429 -
Cortex; a Journal Devoted To the Study... Jun 2021Prosopometamorphopsia is an extremely rare disorder of visual perception characterised by facial distortions. We here review 81 cases (eight new ones and 73 cases... (Review)
Review
Prosopometamorphopsia is an extremely rare disorder of visual perception characterised by facial distortions. We here review 81 cases (eight new ones and 73 cases published over the past century) to shed light on the perception of face gestalts. Our analysis indicates that the brain systems underlying the perception of face gestalts have genuine network properties, in the sense that they are widely disseminated and built such that spatially normal perception of faces can be maintained even when large parts of the network are compromised. We found that bilateral facial distortions were primarily associated with right-sided and bilateral occipital lesions, and unilateral facial distortions with lesions ipsilateral to the distorted hemifield and with the splenium of the corpus callosum. We also found tentative evidence for the involvement of the left frontal regions in the fusing of vertical hemi-images of faces, and of right parietal regions in the fusing of horizontal hemi-images. Evidence supporting the remarkable adaptability of the network comes from the relatively high recovery rates that we found, from the ipsilateral hemifield predominance of hemi-prosopometamorphopsia, and from a phenomenon called cerebral asthenopia (heightened visual fatigability) which points to the dynamic nature of compensatory mechanisms maintaining normal face perception, even in chronic cases of prosopometamorphopsia. Finally, our analysis suggests that specialised networks for the representation of face gestalts in familiar-versus-unfamiliar faces and for own-versus-other face may be present, although this is in need of further study.
Topics: Brain; Brain Mapping; Corpus Callosum; Facial Recognition; Humans; Magnetic Resonance Imaging; Pattern Recognition, Visual; Visual Perception
PubMed: 33865569
DOI: 10.1016/j.cortex.2021.03.001 -
Annual Review of Vision Science Sep 2018The perceptual consequences of eye movements are manifold: Each large saccade is accompanied by a drop of sensitivity to luminance-contrast, low-frequency stimuli,... (Review)
Review
The perceptual consequences of eye movements are manifold: Each large saccade is accompanied by a drop of sensitivity to luminance-contrast, low-frequency stimuli, impacting both conscious vision and involuntary responses, including pupillary constrictions. They also produce transient distortions of space, time, and number, which cannot be attributed to the mere motion on the retinae. All these are signs that the visual system evokes active processes to predict and counteract the consequences of saccades. We propose that a key mechanism is the reorganization of spatiotemporal visual fields, which transiently increases the temporal and spatial uncertainty of visual representations just before and during saccades. On one hand, this accounts for the spatiotemporal distortions of visual perception; on the other hand, it implements a mechanism for fusing pre- and postsaccadic stimuli. This, together with the active suppression of motion signals, ensures the stability and continuity of our visual experience.
Topics: Attention; Contrast Sensitivity; Humans; Perceptual Masking; Pupil; Saccades; Space Perception; Time Perception; Visual Perception
PubMed: 30222534
DOI: 10.1146/annurev-vision-091517-034317 -
Attention, Perception & Psychophysics Jan 2020Anne Treisman investigated many aspects of perception, and in particular the roles of different forms of attention. Four aspects of her work are reviewed here, including... (Review)
Review
Anne Treisman investigated many aspects of perception, and in particular the roles of different forms of attention. Four aspects of her work are reviewed here, including visual search, set mean perception, perception in special populations, and binocular rivalry. The importance of the breakthrough in each case is demonstrated. Search is easy or slow depending on whether it depends on the application of global or focused attention. Mean perception depends on global attention and affords simultaneous representation of the means of at least two sets of elements, and then of comparing them. Deficits exhibited in Balint's or unilateral neglect patients identify basic sensory system mechanisms. And, the ability to integrate binocular information for stereopsis despite simultaneous binocular rivalry for color, demonstrates the division of labor underlying visual system computations. All these studies are related to an appreciation of the difference between perceiving the gist of a scene, its elements or objects, versus perceiving the details of the scene and its components. This relationship between Anne Treisman's revolutionary discoveries and the concept of gist perception is the core of the current review.
Topics: Attention; Depth Perception; Female; History, 20th Century; Humans; Male; Psychophysiology; Vision Disparity; Vision, Binocular; Visual Perception
PubMed: 31529208
DOI: 10.3758/s13414-019-01797-2 -
Proceedings. Biological Sciences Dec 2023We reveal a unique visual perception before feature-integration of colour and motion in infants. Visual perception is established by the integration of multiple...
We reveal a unique visual perception before feature-integration of colour and motion in infants. Visual perception is established by the integration of multiple features, such as colour and motion direction. The mechanism of feature integration benefits from the ongoing interplay between feedforward and feedback loops, yet our comprehension of this causal connection remains incomplete. Researchers have explored the role of recurrent processing in feature integration by studying a visual illusion called 'misbinding', wherein visual characteristics are erroneously merged, resulting in a perception distinct from the originally presented stimuli. Anatomical investigations have revealed that the neural pathways responsible for recurrent connections are underdeveloped in early infants. Therefore, there is a possibility that younger infants could potentially perceive the physically presented visual information that adults miss due to misbinding. Here, we demonstrate that infants less than half a year old showed no misbinding; thus, they perceived the physically presented visual information, while infants more than half a year old perceived incorrectly integrated visual information, showing misbinding. Our findings indicate that recurrent processing barely functions in infants younger than six months of age and that visual information that should have been originally integrated is perceived as it is without being integrated.
Topics: Adult; Humans; Infant; Motion Perception; Visual Perception; Illusions
PubMed: 38052443
DOI: 10.1098/rspb.2023.2134 -
Psychonomic Bulletin & Review Apr 2024How do we perceptually and cognitively organize incoming stimulation? A century ago, Gestalt psychologists posited the law of Prägnanz: psychological organization will...
How do we perceptually and cognitively organize incoming stimulation? A century ago, Gestalt psychologists posited the law of Prägnanz: psychological organization will always be as 'good' as possible given the prevailing conditions. To make the Prägnanz law a useful statement, it needs to be specified further (a) what a 'good' psychological organization entails, (b) how the Prägnanz tendency can be realized, and (c) which conditions need to be taken into account. Although the Gestalt school did provide answers to these questions, modern-day mentions of Prägnanz or good Gestalt often lack these clarifications. The concept of Prägnanz has been (mis)understood in many different ways, and by looking back on the rich history of the concept, we will attempt to present a more fine-grained view and promote a renewed understanding of the central role of Prägnanz in visual perception and beyond. We review Gestalt psychology's answers to the questions listed above, and also discuss the four main uses of the Prägnanz concept in more detail: (a) a Prägnanz tendency in each organizational process, (b) Prägnanz as a property of a Gestalt, (c) Prägnanz steps as internal reference points, and (d) Prägnanz in relation to aesthetic appreciation. As a key takeaway, Prägnanz is a multifaceted Gestalt psychological concept indicating the "goodness" of an experienced organization. Both the removal of unnecessary details and the emphasis on characteristic features of the overall organization compared to a reference organization can contribute to the emergence of a 'better' Gestalt. The stimulus constellation is not the only factor in determining the goodness of an organization, also the stimulus' interaction with an individual in a specific spatial and temporal context plays a role. Taking the ideas on Prägnanz as a generative framework and keeping the original Gestalt psychological context in mind, future research on perceptual organization can improve our understanding of the principles underlying psychological organization by further specifying how different organizational principles interact in concrete situations. Public significance statement: This paper reviews what a 'good' psychological organization entails, and how the incoming stimulation is clarified in human perception to achieve the best possible psychological organization. The review debunks common misconceptions on the meaning of "goodness" and synthesizes the most important perspectives and developments on "goodness" from its conception until now.
Topics: Humans; Gestalt Theory; Visual Perception
PubMed: 37787874
DOI: 10.3758/s13423-023-02344-9 -
Annual Review of Vision Science Sep 2017Visual textures are a class of stimuli with properties that make them well suited for addressing general questions about visual function at the levels of behavior and... (Review)
Review
Visual textures are a class of stimuli with properties that make them well suited for addressing general questions about visual function at the levels of behavior and neural mechanism. They have structure across multiple spatial scales, they put the focus on the inferential nature of visual processing, and they help bridge the gap between stimuli that are analytically convenient and the complex, naturalistic stimuli that have the greatest biological relevance. Key questions that are well suited for analysis via visual textures include the nature and structure of perceptual spaces, modulation of early visual processing by task, and the transformation of sensory stimuli into patterns of population activity that are relevant to perception.
Topics: Attention; Discrimination, Psychological; Humans; Pattern Recognition, Visual; Visual Cortex; Visual Fields; Visual Perception
PubMed: 28937948
DOI: 10.1146/annurev-vision-102016-061316 -
Scientific Reports Feb 2023Visual perception is limited by spatial resolution, the ability to discriminate fine details. Spatial resolution not only declines with eccentricity but also differs for...
Visual perception is limited by spatial resolution, the ability to discriminate fine details. Spatial resolution not only declines with eccentricity but also differs for polar angle locations around the visual field, also known as 'performance fields'. To compensate for poor peripheral resolution, we make rapid eye movements-saccades-to bring peripheral objects into high-acuity foveal vision. Already before saccade onset, visual attention shifts to the saccade target location and prioritizes visual processing. This presaccadic shift of attention improves performance in many visual tasks, but whether it changes resolution is unknown. Here, we investigated whether presaccadic attention sharpens peripheral spatial resolution; and if so, whether such effect interacts with performance fields asymmetries. We measured acuity thresholds in an orientation discrimination task during fixation and saccade preparation around the visual field. The results revealed that presaccadic attention sharpens acuity, which can facilitate a smooth transition from peripheral to foveal representation. This acuity enhancement is similar across the four cardinal locations; thus, the typically robust effect of presaccadic attention does not change polar angle differences in resolution.
Topics: Visual Perception; Visual Fields; Vision, Ocular; Visual Acuity; Saccades; Photic Stimulation
PubMed: 36807313
DOI: 10.1038/s41598-023-29990-2