George Sperling · 1993
Abstract : The publications describe progress in two related areas of visual information processing: motion processing and visual attention. The full equivalence between Reichart motion detection and Fourier motion analysis (first-order motion processing) was proved formally. A new experimental paradigm was developed to test the model of nonFourier (2nd-order) motion processing. This model, which accounts for the perception of motion-from-texture, consists of a stage of linear spatio-temporal filtering followed by fullwave rectification and then by standard (Reichart) motion analysis. It was demonstrated that human 2nd-order motion is, for practical purposes, one-dimensional (i.e., a single channel system). The spatial filter that this channel utilizes was measured and found to be lowpass. Work on attentional processes in visual task using rapid sequences of superimposed patterns showed that highly trained subjects were unable to use gross physical differences to filter out unattended items at an early stage of perceptual processing. On the contrary, the results are explained by postulating that attended and unattended elements of the input are tagged as such at an early-stage, and are then discriminated later on the of this tag. (Author)
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George Sperling · 1997
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Bocci T., Pietrasanta M., Cerri C. et al. · CINECA IRIS Institutial research information system (University of Pisa) · 2014
Visual cortical areas in the two sides of the brain are interconnected by interhemispheric fibers passing through the splenium of the corpus callosum. In this review, we summarize data concerning the anatomical features of visual callosal connections, their roles in basic visual processing, and how their alterations contribute to visual deficits in different human neuropathologies. Splenial fibers represent a population of excitatory axons with varying diameters, which interconnect cortical columns with similar functional properties (i.e., same orientation selectivity) in the two hemispheres. Their branches activate simultaneously distinct iso-oriented columns in the contralateral hemisphere, thus mediating forms of stimulus-dependent interhemispheric synchronization. Callosal branches also make synapses onto GABAergic cells, resulting in an inhibitory modulation of visual processing that involves both iso-oriented and cross-oriented cortical networks. Interhemispheric inhibition appears to predominate at short latencies following callosal activation, whereas excitation becomes more robust with increasing delays. These callosal effects are dynamically adapted to the incoming visual activity, so that stimuli providing only weak afferent input are facilitated by callosal pathways, whereas strong visual input via the retinogeniculate pathway tends to be offset by transcallosal inhibition. We also review data highlighting the contribution of callosal input activity to maturation of visual function during early 'critical periods' in brain development and describe how interhemispheric transfer of visual information is rerouted in cases of callosal agenesis or following splenial damage. Finally, we provide an overview of alterations in splenium anatomy or function that may be at the basis of visual defects in several pathologic conditions.
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Carol L. Hodes · Journal of Visual Literacy · 1998
Visual information brings about a type of information processing ca involves the simultaneous use of both a verbal and a nonverbal code. Understanding the human information processing system and the role of visuals within it. deepens ourunderstanding of visual literacy. Nonverbal mental processes can be used successfully to visualize important informationduring learning. Several studies report that dual coding has been used to improve learning and accuracy. Such methods are not widely proven but show promise to help learners capitalize on the advantages of being visual literate.
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William V. Padula, Jonathan Jenness · 2021
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Paula Handford (6501571), Anthony Nizza (6533408) · Figshare · 2024
This course will focus on visual information processing testing and give students an organized approach to identify deficits that may have an impact on reading and learning. A multidisciplinary approach to the management of learning problems will be presented. The course will provide the doctrine behind standardized testing. In addition, an overview of learning disabilities and dyslexia will be presented. A sequential management plan will be introduced for treating patients with visual processing disorders. A brief introduction to Acquired Brain Injury (ABI) and subsequent testing and training will be used to familiarize the student with current treatment options for ABI.
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Miguel A. Garcı́a-Pérez · Spatial Vision · 1988
A multichannel model incorporating visual inhomogeneity is presented in this paper. The parameters that describe inhomogeneity have been experimentally obtained both at threshold and in several suprathreshold conditions. At threshold, probability summation is taken into account in order to determine the spatial extent of visual channels from experimental data showing an asymptotic increase in sensitivity with increasing grating area. At suprathreshold contrast, the region where luminance variations at several scales are visible has also been found. The results support a spatially limited multichannel model of early visual processing and set out a basis for studying perceptual phenomena from the viewpoint of linear space-variant visual processing.
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Christina Esposito (6343304), Jennifer Idoni (6869748), Amanda Brewer (19757394) et al. · Figshare · 2024
<div>This course will focus on visual information processing testing and give students an organized approach to identify visual deficits that may have an impact on reading and learning. The doctrine behind standardized testing will be discussed. An overview of learning disabilities will be presented and students will be introduced to the multidisciplinary approach in management of vision related learning problems. Sequential management plans will be provided for treating patients with visual processing disorders. Students will be familiarized with current treatment options for acquired brain injury.</div>
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Webb Barbara, Mangan Michael, Ardin Paul · Frontiers in Physiology · 2013
Frontiers Events is a rapidly growing calendar management system dedicated to the scheduling of academic events. This includes announcements and invitations, participant listings and search functionality, abstract handling and publication, related events and post-event exchanges. Whether an organizer or participant, make your event a Frontiers Event!
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Kolinsky, Régine · Dépôt institutionnel de l'Université libre de Bruxelles (Université Libre de Bruxelles) · 1986
info:eu-repo/semantics/nonPublished
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James D. Sanders · scholarworks - UTEP (The University of Texas at El Paso) · 1999
Three experiments were conducted to test the theoretical distinctions between the types of perceptual processing employed by the right and left cerebral hemispheres, and the mental representations that emerge as a consequence of this processing. Each study is predicated on the assumption that the hemispheres are more efficient at applying distinct visual processing strategies. Specifically, the right hemisphere is more efficient at holistic visual processing that mediates the construction of exemplar-based mental representations. In contrast, the left hemisphere is more efficient at part-based visual processing that mediates the construction of category-based menial representations. Study 1 investigated hemispheric asymmetries in relation to the mere exposure effect for photographs depicting individual faces. Study 2 investigated the ability of the hemispheres to perform same-person and same-gender categorizations. Study 3 investigated hemispheric asymmetries in categorizing individuals into newly learned groups. Collectively, the three experiments provide evidence that the hemispheres are more efficient at applying distinct visual processing strategies (i.e., holistic or part-based in the right and left hemisphere, respectively). Furthermore, these processing strategies support the construction of distinct exemplar or category mental representations. Implications for models of recognition, categorization, and impression formation are discussed.
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Sarah C. Johnson, Natasha Lowery, Christian G. Kohler et al. · Biological Psychiatry · 2005
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Huck, F O, Juday, R D · CERN Document Server (European Organization for Nuclear Research) · 1992
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Graziella Tonfoni · 1996
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Steve Croker, Frances A. Maratos · Child Development Research · 2011
The aim of this study was to investigate visual processing speeds in children. A rapid serial visual presentation (RSVP) task with schematic faces as stimuli was given to ninety-nine 6–10-year-old children as well as a short form of the WISC-III. Participants were asked to determine whether a happy face stimulus was embedded in a stream of distracter stimuli. Presentation time was gradually reduced from 500 ms per stimulus to 100 ms per stimulus, in 50 ms steps. The data revealed that (i) RSVP speed increases with age, (ii) children aged 8 years and over can discriminate stimuli presented every 100 ms—the speed typically used with RSVP procedures in adult and adolescent populations, and (iii) RSVP speed is significantly correlated with digit span and object assembly. In consequence, the RSVP paradigm presented here is appropriate for use in further investigations of processes of temporal attention within this cohort.
Cited by 5Open access
Lee, Tai Sing · KiltHub Repository · 2018
Vision is the analysis of patterns in visual images with the view to understanding the objects and the physical processes in the world that generate them. Locally, visual patterns are highly ambiguous and subject to multiple interpretations. Image structures surrounding the pattern being analyzed can provide additional constraints or context to disambiguate the interpretation. The resulting contextual influences are ubiquitous in visual perception and manifest at the neuronal level as the modulation of the activity of neurons by image structures outside their classical receptive fields.
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Ken Nakayama · 1993
Abstract : We completed a comprehensive theoretical account of visual surface representation based on a new understanding of many of our recently reported perceptual phenomena. In particular, we determined the degree to which the 'generic view principle' can explain these new findings and also extended its domain to a large number of perceptual phenomena (Shimojo and Nakayama, 1992). We apply the generic sampling principle which indicates that the visual system acts as if it were viewing surface layouts from generic, not accidental vantage points. Through the observer's experience of optical sampling, which can be characterize geometrically, the visual system makes associative connections between images and surfaces, passively internalizing the conditional probabilities of image sampling from surfaces. In turn, this enables the visual system to determine which surface a given image most strongly predicts. Thus, visual surface perception can be considered as inverse ecological optics based on learning through ecological optics. Because of its neglect of prior probabilities and higher level knowledge, visual surface perception deviates from strict Bayesian notions of inference.
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Ken Nakayama · 1994
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Luigi Atzori, Fernando Pereira, Riccardo Leonardi · Lecture notes in computer science · 2006
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Irish,Kenneth M., Orszulak,James H. · Defense Technical Information Center (DTIC) · 1974
This report describes a two-phase program to further the development of visual simulation video processing techniques as applied to a wide angle optical probe/TV camera. Phase 1 included the study of applicable wide-angle display techniques, study of additional processing of the probe's video signal for proper mating to a display, study of color visual requirements, and a review of state-of-the-art separation techniques for TV cameras. Phase 2 dealt with the construction of a video matrix generator to provide the necessary electronic processing to mate the optical probe/TV camera system to applicable wide angle displays.
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