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Journal of Vision May 2011Crowding occurs when stimuli in the peripheral fields become harder to identify when flanked by other items. This phenomenon has been demonstrated extensively with...
Crowding occurs when stimuli in the peripheral fields become harder to identify when flanked by other items. This phenomenon has been demonstrated extensively with simple patterns (e.g., Gabors and letters). Here, we characterize crowding for everyday objects. We presented three-item arrays of objects and letters, arranged radially and tangentially in the lower visual field. Observers identified the central target, and we measured contrast energy thresholds as a function of target-to-flanker spacing. Object crowding was similar to letter crowding in spatial extent but was much weaker. The average elevation in threshold contrast energy was in the order of 1 log unit for objects as compared to 2 log units for letters and silhouette objects. Furthermore, we examined whether the exterior and interior features of an object are differentially affected by crowding. We used a circular aperture to present or exclude the object interior. Critical spacings for these aperture and "donut" objects were similar to those of intact objects. Taken together, these findings suggest that crowding between letters and objects are essentially due to the same mechanism, which affects equally the interior and exterior features of an object. However, for objects defined with varying shades of gray, it is much easier to overcome crowding by increasing contrast.
Topics: Anisotropy; Contrast Sensitivity; Discrimination, Psychological; Form Perception; Humans; Pattern Recognition, Visual; Perceptual Masking; Photic Stimulation; Sensory Thresholds; Space Perception; Visual Fields; Visual Perception
PubMed: 21613388
DOI: 10.1167/11.6.19 -
Current Biology : CB Oct 2011Attention is crucial for visual perception because it allows the visual system to effectively use its limited resources by selecting behaviorally and cognitively...
Attention is crucial for visual perception because it allows the visual system to effectively use its limited resources by selecting behaviorally and cognitively relevant stimuli from the large amount of information impinging on the eyes. Reflexive, stimulus-driven attention is essential for successful interactions with the environment because it can, for example, speed up responses to life-threatening events. It is commonly believed that exogenous attention operates in the retinotopic coordinates of the early visual system. Here, using a novel experimental paradigm [1], we show that a nonretinotopic cue improves both accuracy and reaction times in a visual search task. Furthermore, the influence of the cue is limited both in space and time, a characteristic typical of exogenous cueing. These and other recent findings show that many more aspects of vision are processed nonretinotopically than previously thought.
Topics: Attention; Cues; Humans; Pattern Recognition, Visual; Space Perception; Visual Perception
PubMed: 22000104
DOI: 10.1016/j.cub.2011.08.059 -
Neuroscience Bulletin Jan 2023Accurate self-motion perception, which is critical for organisms to survive, is a process involving multiple sensory cues. The two most powerful cues are visual (optic... (Review)
Review
Accurate self-motion perception, which is critical for organisms to survive, is a process involving multiple sensory cues. The two most powerful cues are visual (optic flow) and vestibular (inertial motion). Psychophysical studies have indicated that humans and nonhuman primates integrate the two cues to improve the estimation of self-motion direction, often in a statistically Bayesian-optimal way. In the last decade, single-unit recordings in awake, behaving animals have provided valuable neurophysiological data with a high spatial and temporal resolution, giving insight into possible neural mechanisms underlying multisensory self-motion perception. Here, we review these findings, along with new evidence from the most recent studies focusing on the temporal dynamics of signals in different modalities. We show that, in light of new data, conventional thoughts about the cortical mechanisms underlying visuo-vestibular integration for linear self-motion are challenged. We propose that different temporal component signals may mediate different functions, a possibility that requires future studies.
Topics: Animals; Humans; Motion Perception; Bayes Theorem; Optic Flow; Cues; Vestibule, Labyrinth; Photic Stimulation; Visual Perception
PubMed: 35821337
DOI: 10.1007/s12264-022-00916-8 -
Attention, Perception & Psychophysics Jul 2022Maintaining object correspondence among multiple moving objects is an essential task of the perceptual system in many everyday life activities. A substantial body of...
Maintaining object correspondence among multiple moving objects is an essential task of the perceptual system in many everyday life activities. A substantial body of research has confirmed that observers are able to track multiple target objects amongst identical distractors based only on their spatiotemporal information. However, naturalistic tasks typically involve the integration of information from more than one modality, and there is limited research investigating whether auditory and audio-visual cues improve tracking. In two experiments, we asked participants to track either five target objects or three versus five target objects amongst similarly indistinguishable distractor objects for 14 s. During the tracking interval, the target objects bounced occasionally against the boundary of a centralised orange circle. A visual cue, an auditory cue, neither or both coincided with these collisions. Following the motion interval, the participants were asked to indicate all target objects. Across both experiments and both set sizes, our results indicated that visual and auditory cues increased tracking accuracy although visual cues were more effective than auditory cues. Audio-visual cues, however, did not increase tracking performance beyond the level of purely visual cues for both high and low load conditions. We discuss the theoretical implications of our findings for multiple object tracking as well as for the principles of multisensory integration.
Topics: Attention; Auditory Perception; Cues; Humans; Motion; Motion Perception; Photic Stimulation; Visual Perception
PubMed: 35610410
DOI: 10.3758/s13414-022-02492-5 -
Journal of Vision Dec 2023Gestalten in visual perception are defined by emergent properties of the whole, which cannot be predicted from the sum of its parts; rather, they arise by virtue of... (Review)
Review
Gestalten in visual perception are defined by emergent properties of the whole, which cannot be predicted from the sum of its parts; rather, they arise by virtue of inherent principles, the Laws of Seeing. This review attempts to assign neurophysiological correlates to select emergent properties in motion and contour perception and proposes parallels to the processing of local versus global attributes by classical versus contextual receptive fields. The aim is to identify Gestalt neurons in the visual system to account for the Laws of Seeing in causal terms and to explain "Why do things look as they do" (Koffka, 1935, p. 76).
Topics: Humans; Visual Perception; Neurons; Form Perception; Motion Perception
PubMed: 38091030
DOI: 10.1167/jov.23.14.4 -
Journal of Vision Feb 2022Continuous tracking is a newly developed technique that allows fast and efficient data acquisition by asking participants to "track" a stimulus varying in some property...
Continuous tracking is a newly developed technique that allows fast and efficient data acquisition by asking participants to "track" a stimulus varying in some property (usually position in space). Tracking is a promising paradigm for the investigation of dynamic features of perception and could be particularly well suited for testing ecologically relevant situations difficult to study with classical psychophysical paradigms. The high rate of data collection may be useful in studies on clinical populations and children, who are unable to undergo long testing sessions. In this study, we designed tracking experiments with two novel stimulus features, numerosity and size, proving the feasibility of the technique outside standard object tracking. We went on to develop an ideal observer model that characterizes the results in terms of efficiency of conversion of stimulus strength into responses, and identification of early and late noise sources. Our ideal observer closely modeled results from human participants, providing a generalized framework for the interpretation of tracking data. The proposed model allows to use the tracking paradigm in various perceptual domains, and to study the divergence of human participants from ideal behavior.
Topics: Child; Humans; Models, Psychological; Motion Perception; Perceptual Masking; Space Perception; Visual Perception
PubMed: 35103756
DOI: 10.1167/jov.22.2.3 -
Cognition Sep 2017How do perception and language interact to form the representations that guide our thoughts and actions over the short-term? Here, we provide a first examination of this...
How do perception and language interact to form the representations that guide our thoughts and actions over the short-term? Here, we provide a first examination of this question by investigating the role of verbal labels in a continuous visual working memory (WM) task. Across four experiments, participants retained in memory the continuous color of a set of dots which were presented sequentially (Experiments 1-3) or simultaneously (Experiment 4). At test, they reproduced the colors of all dots using a color wheel. During stimulus presentation participants were required to either label the colors (color labeling) or to repeat "bababa" aloud (articulatory suppression), hence prompting or preventing verbal labeling, respectively. We tested four competing hypotheses of the labeling effect: (1) labeling generates a verbal representation that overshadows the visual representation; (2) labeling yields a verbal representation in addition to the visual one; (3) the labels function as a retrieval cue, adding distinctiveness to items in memory; and (4) labels activate visual categorical representations in long-term memory. Collectively, our experiments show that labeling does not overshadow the visual input; it augments it. Mixture modeling showed that labeling increased the quantity and quality of information in WM. Our findings are consistent with the hypothesis that labeling activates visual long-term categorical representations which help in reducing the noise in the internal representations of the visual stimuli in WM.
Topics: Adult; Color Perception; Female; Humans; Language; Male; Memory, Short-Term; Neuropsychological Tests; Visual Perception; Young Adult
PubMed: 28595141
DOI: 10.1016/j.cognition.2017.05.038 -
Journal of Vision Aug 2007Visual clutter concerns designers of user interfaces and information visualizations. This should not surprise visual perception researchers because excess and/or...
Visual clutter concerns designers of user interfaces and information visualizations. This should not surprise visual perception researchers because excess and/or disorganized display items can cause crowding, masking, decreased recognition performance due to occlusion, greater difficulty at both segmenting a scene and performing visual search, and so on. Given a reliable measure of the visual clutter in a display, designers could optimize display clutter. Furthermore, a measure of visual clutter could help generalize models like Guided Search (J. M. Wolfe, 1994) by providing a substitute for "set size" more easily computable on more complex and natural imagery. In this article, we present and test several measures of visual clutter, which operate on arbitrary images as input. The first is a new version of the Feature Congestion measure of visual clutter presented in R. Rosenholtz, Y. Li, S. Mansfield, and Z. Jin (2005). This Feature Congestion measure of visual clutter is based on the analogy that the more cluttered a display or scene is, the more difficult it would be to add a new item that would reliably draw attention. A second measure of visual clutter, Subband Entropy, is based on the notion that clutter is related to the visual information in the display. Finally, we test a third measure, Edge Density, used by M. L. Mack and A. Oliva (2004) as a measure of subjective visual complexity. We explore the use of these measures as stand-ins for set size in visual search models and demonstrate that they correlate well with search performance in complex imagery. This includes the search-in-clutter displays of J. M. Wolfe, A. Oliva, T. S. Horowitz, S. Butcher, and A. Bompas (2002) and Bravo and Farid (2004), as well as new search experiments. An additional experiment suggests that color variability, accounted for by Feature Congestion but not the Edge Density measure or the Subband Entropy measure, does matter for visual clutter.
Topics: Attention; Color Perception; Contrast Sensitivity; Entropy; Humans; Models, Psychological; Pattern Recognition, Visual; Perceptual Masking; Space Perception; Visual Perception
PubMed: 18217832
DOI: 10.1167/7.2.17 -
Vision Research Jun 2009This article argues that phenomenological description and neurophysiological correlation complement each other in perception research. Whilst phenomena constitute the... (Review)
Review
This article argues that phenomenological description and neurophysiological correlation complement each other in perception research. Whilst phenomena constitute the material, neuronal mechanisms are indispensable for their explanation. Numerous examples of neurophysiological correlates show that the correlation of phenomenology and neurophysiology is fruitful. Phenomena for which neuronal mechanism have been found include: (in area V1) filling-in of real and artificial scotomata, contour integration, figure-ground segregation by orientation contrast, amodal completion, and motion transparency; (in V2) modal completion, border ownership, surface transparency, and cyclopean perception; (in V3) alignment in dotted contours, and filling-in with dynamic texture; (in V4) colour constancy; (in MT) shape by accretion/deletion, grouping by coherent motion, apparent motion in motion quartets, motion in apertures, and biological motion. Results suggest that in monkey visual cortex, occlusion cues, including stereo depth, are predominantly processed in lower areas, whereas mechanisms for grouping and motion are primarily represented in higher areas. More correlations are likely to emerge as neuroscientists strive for a better understanding of visual perception. The paper concludes with a review of major achievements in visual neuroscience pertinent to the study of the phenomena under consideration.
Topics: Animals; Color Perception; Contrast Sensitivity; Cues; Depth Perception; Humans; Macaca mulatta; Motion Perception; Optical Illusions; Psychophysics; Visual Cortex; Visual Perception
PubMed: 19303897
DOI: 10.1016/j.visres.2009.02.022 -
Neuron Nov 2005Three classes of perceptual phenomena have repeatedly been associated with autism spectrum disorder (ASD): superior processing of fine detail (local structure), either... (Review)
Review
Three classes of perceptual phenomena have repeatedly been associated with autism spectrum disorder (ASD): superior processing of fine detail (local structure), either inferior processing of overall/global structure or an ability to ignore disruptive global/contextual information, and impaired motion perception. This review evaluates the quality of the evidence bearing on these three phenomena. We argue that while superior local processing has been robustly demonstrated, conclusions about global processing cannot be definitively drawn from the experiments to date, which have generally not precluded observers using more local cues. Perception of moving stimuli is impaired in ASD, but explanations in terms of magnocellular/dorsal deficits do not appear to be sufficient. We suggest that abnormalities in the superior temporal sulcus (STS) may provide a neural basis for the range of motion-processing deficits observed in ASD, including biological motion perception. Such an explanation may also provide a link between perceptual abnormalities and specific deficits in social cognition associated with autism.
Topics: Autistic Disorder; Humans; Mental Processes; Models, Biological; Photic Stimulation; Visual Fields; Visual Perception
PubMed: 16269366
DOI: 10.1016/j.neuron.2005.10.018