WorldWideScience

Sample records for graded visual perception

  1. The Analysis of Reading Skills and Visual Perception Levels of First Grade Turkish Students

    Science.gov (United States)

    Memis, Aysel; Sivri, Diler Ayvaz

    2016-01-01

    In this study, primary school first grade students' reading skills and visual perception levels were investigated. Sample of the study, which was designed with relational scanning model, consisted of 168 first grade students studying at three public primary schools in Kozlu, Zonguldak, in 2013-2014 education year. Students' reading level, reading…

  2. Visual Arts Teaching in Kindergarten through 3rd-Grade Classrooms in the UAE: Teacher Profiles, Perceptions, and Practices

    Science.gov (United States)

    Buldu, Mehmet; Shaban, Mohamed S.

    2010-01-01

    This study portrayed a picture of kindergarten through 3rd-grade teachers who teach visual arts, their perceptions of the value of visual arts, their visual arts teaching practices, visual arts experiences provided to young learners in school, and major factors and/or influences that affect their teaching of visual arts. The sample for this study…

  3. An fMRI study of the neural correlates of graded visual perception

    DEFF Research Database (Denmark)

    Christensen, Mark Schram; Ramsoy, T.Z.; Lund, T.E.

    2006-01-01

    The neural correlates of clearly perceived visual stimuli have been reported previously in contrast to unperceived stimuli, but it is uncertain whether intermediate or graded perceptual experiences correlate with different patterns of neural activity. In this study, the subjective appearance...... of briefly presented visual stimuli was rated individually by subjects with respect to perceptual clarity: clear, vague or no experience of a stimulus. Reports of clear experiences correlated with activation in a widespread network of brain areas, including parietal cortex, prefrontal cortex, premotor cortex...... of activation. Different degrees of perceptual clarity were reflected both in the degree to which activation was found within parts of the network serving a clear conscious percept, and additional unique activation patterns for different degrees of perceptual clarity. Our findings support theories proposing...

  4. Early Local Activity in Temporal Areas Reflects Graded Content of Visual Perception

    Directory of Open Access Journals (Sweden)

    Chiara Francesca Tagliabue

    2016-04-01

    Full Text Available In visual cognitive neuroscience the debate on consciousness is focused on two major topics: the search for the neural correlates of the different properties of visual awareness and the controversy on the graded versus dichotomous nature of visual conscious experience. The aim of this study is to search for the possible neural correlates of different grades of visual awareness investigating the Event Related Potentials (ERPs to reduced contrast visual stimuli whose perceptual clarity was rated on the four-point Perceptual Awareness Scale (PAS. Results revealed a left centro-parietal negative deflection (Visual Awareness Negativity; VAN peaking at 280-320 ms from stimulus onset, related to the perceptual content of the stimulus, followed by a bilateral positive deflection (Late Positivity; LP peaking at 510-550 ms over almost all electrodes, reflecting post-perceptual processes performed on such content. Interestingly, the amplitude of both deflections gradually increased as a function of visual awareness. Moreover, the intracranial generators of the phenomenal content (VAN were found to be located in the left temporal lobe. The present data thus seem to suggest 1 that visual conscious experience is characterized by a gradual increase of perceived clarity at both behavioral and neural level and 2 that the actual content of perceptual experiences emerges from early local activation in temporal areas, without the need of later widespread frontal engagement.

  5. Visual art and visual perception

    NARCIS (Netherlands)

    Koenderink, Jan J.

    2015-01-01

    Visual art and visual perceptionVisual art’ has become a minor cul-de-sac orthogonal to THE ART of the museum directors and billionaire collectors. THE ART is conceptual, instead of visual. Among its cherished items are the tins of artist’s shit (Piero Manzoni, 1961, Merda d’Artista) “worth their

  6. Visual art and visual perception

    OpenAIRE

    Koenderink, Jan J.

    2015-01-01

    Visual art and visual perceptionVisual art’ has become a minor cul-de-sac orthogonal to THE ART of the museum directors and billionaire collectors. THE ART is conceptual, instead of visual. Among its cherished items are the tins of artist’s shit (Piero Manzoni, 1961, Merda d’Artista) “worth their weight in gold”. I perceive a metabletic (van den Berg, 1956) parallel to philosophy transforming itself into speculative logic games, and psychology going cognitive by freeing itself from phenomen...

  7. Music Alters Visual Perception

    NARCIS (Netherlands)

    Jolij, Jacob; Meurs, Maaike

    2011-01-01

    Background: Visual perception is not a passive process: in order to efficiently process visual input, the brain actively uses previous knowledge (e. g., memory) and expectations about what the world should look like. However, perception is not only influenced by previous knowledge. Especially the

  8. Music alters visual perception.

    Science.gov (United States)

    Jolij, Jacob; Meurs, Maaike

    2011-04-21

    Visual perception is not a passive process: in order to efficiently process visual input, the brain actively uses previous knowledge (e.g., memory) and expectations about what the world should look like. However, perception is not only influenced by previous knowledge. Especially the perception of emotional stimuli is influenced by the emotional state of the observer. In other words, how we perceive the world does not only depend on what we know of the world, but also by how we feel. In this study, we further investigated the relation between mood and perception. We let observers do a difficult stimulus detection task, in which they had to detect schematic happy and sad faces embedded in noise. Mood was manipulated by means of music. We found that observers were more accurate in detecting faces congruent with their mood, corroborating earlier research. However, in trials in which no actual face was presented, observers made a significant number of false alarms. The content of these false alarms, or illusory percepts, was strongly influenced by the observers' mood. As illusory percepts are believed to reflect the content of internal representations that are employed by the brain during top-down processing of visual input, we conclude that top-down modulation of visual processing is not purely predictive in nature: mood, in this case manipulated by music, may also directly alter the way we perceive the world.

  9. Music alters visual perception.

    Directory of Open Access Journals (Sweden)

    Jacob Jolij

    Full Text Available BACKGROUND: Visual perception is not a passive process: in order to efficiently process visual input, the brain actively uses previous knowledge (e.g., memory and expectations about what the world should look like. However, perception is not only influenced by previous knowledge. Especially the perception of emotional stimuli is influenced by the emotional state of the observer. In other words, how we perceive the world does not only depend on what we know of the world, but also by how we feel. In this study, we further investigated the relation between mood and perception. METHODS AND FINDINGS: We let observers do a difficult stimulus detection task, in which they had to detect schematic happy and sad faces embedded in noise. Mood was manipulated by means of music. We found that observers were more accurate in detecting faces congruent with their mood, corroborating earlier research. However, in trials in which no actual face was presented, observers made a significant number of false alarms. The content of these false alarms, or illusory percepts, was strongly influenced by the observers' mood. CONCLUSIONS: As illusory percepts are believed to reflect the content of internal representations that are employed by the brain during top-down processing of visual input, we conclude that top-down modulation of visual processing is not purely predictive in nature: mood, in this case manipulated by music, may also directly alter the way we perceive the world.

  10. Novelty enhances visual perception.

    Directory of Open Access Journals (Sweden)

    Judith Schomaker

    Full Text Available The effects of novelty on low-level visual perception were investigated in two experiments using a two-alternative forced-choice tilt detection task. A target, consisting of a Gabor patch, was preceded by a cue that was either a novel or a familiar fractal image. Participants had to indicate whether the Gabor stimulus was vertically oriented or slightly tilted. In the first experiment tilt angle was manipulated; in the second contrast of the Gabor patch was varied. In the first, we found that sensitivity was enhanced after a novel compared to a familiar cue, and in the second we found sensitivity to be enhanced for novel cues in later experimental blocks when participants became more and more familiarized with the familiar cue. These effects were not caused by a shift in the response criterion. This shows for the first time that novel stimuli affect low-level characteristics of perception. We suggest that novelty can elicit a transient attentional response, thereby enhancing perception.

  11. Novelty enhances visual perception.

    Science.gov (United States)

    Schomaker, Judith; Meeter, Martijn

    2012-01-01

    The effects of novelty on low-level visual perception were investigated in two experiments using a two-alternative forced-choice tilt detection task. A target, consisting of a Gabor patch, was preceded by a cue that was either a novel or a familiar fractal image. Participants had to indicate whether the Gabor stimulus was vertically oriented or slightly tilted. In the first experiment tilt angle was manipulated; in the second contrast of the Gabor patch was varied. In the first, we found that sensitivity was enhanced after a novel compared to a familiar cue, and in the second we found sensitivity to be enhanced for novel cues in later experimental blocks when participants became more and more familiarized with the familiar cue. These effects were not caused by a shift in the response criterion. This shows for the first time that novel stimuli affect low-level characteristics of perception. We suggest that novelty can elicit a transient attentional response, thereby enhancing perception.

  12. Visual working memory contaminates perception

    OpenAIRE

    Kang, Min-Suk; Hong, Sang Wook; Blake, Randolph; Woodman, Geoffrey F.

    2011-01-01

    Indirect evidence suggests that the contents of visual working memory may be maintained within sensory areas early in the visual hierarchy. We tested this possibility using a well-studied motion repulsion phenomenon in which perception of one direction of motion is distorted when another direction of motion is viewed simultaneously. We found that observers misperceived the actual direction of motion of a single motion stimulus if, while viewing that stimulus, they were holding a different mot...

  13. Crossmodal influences on visual perception

    Science.gov (United States)

    Shams, Ladan; Kim, Robyn

    2010-09-01

    Vision is generally considered the dominant sensory modality; self-contained and independent of other senses. In this article, we will present recent results that contradict this view, and show that visual perception can be strongly altered by sound and touch, and such alterations can occur even at early stages of processing, as early as primary visual cortex. We will first review the behavioral evidence demonstrating modulation of visual perception by other modalities. As extreme examples of such modulations, we will describe two visual illusions induced by sound, and a visual illusion induced by touch. Next, we will discuss studies demonstrating modulation of activity in visual areas by stimulation of other modalities, and discuss possible pathways that could underpin such interactions. This will be followed by a discussion of how crossmodal interactions can affect visual learning and adaptation. We will review several studies showing crossmodal effects on visual learning. We will conclude with a discussion of computational principles governing these crossmodal interactions, and review several recent studies that demonstrate that these interactions are statistically optimal.

  14. Attentional episodes in visual perception

    NARCIS (Netherlands)

    Wyble, Brad; Potter, Mary C.; Bowman, Howard; Nieuwenstein, Mark

    Is one's temporal perception of the world truly as seamless as it appears? This article presents a computationally motivated theory suggesting that visual attention samples information from temporal episodes (episodic simultaneous type/serial token model; Wyble, Bowman, & Nieuwenstein, 2009). Breaks

  15. Improving visual perception through neurofeedback

    Science.gov (United States)

    Scharnowski, Frank; Hutton, Chloe; Josephs, Oliver; Weiskopf, Nikolaus; Rees, Geraint

    2012-01-01

    Perception depends on the interplay of ongoing spontaneous activity and stimulus-evoked activity in sensory cortices. This raises the possibility that training ongoing spontaneous activity alone might be sufficient for enhancing perceptual sensitivity. To test this, we trained human participants to control ongoing spontaneous activity in circumscribed regions of retinotopic visual cortex using real-time functional MRI based neurofeedback. After training, we tested participants using a new and previously untrained visual detection task that was presented at the visual field location corresponding to the trained region of visual cortex. Perceptual sensitivity was significantly enhanced only when participants who had previously learned control over ongoing activity were now exercising control, and only for that region of visual cortex. Our new approach allows us to non-invasively and non-pharmacologically manipulate regionally specific brain activity, and thus provide ‘brain training’ to deliver particular perceptual enhancements. PMID:23223302

  16. Visual perception skills testing: preliminary results

    CSIR Research Space (South Africa)

    Smith, Andrew C

    2009-02-01

    Full Text Available Good visual perception skills are important in the effective manipulation of Tangible User Interfaces. This paper reports on the application of a test set researchers have developed specifically to quantify the visual perception skills of children...

  17. Visual memory and visual perception: when memory improves visual search.

    Science.gov (United States)

    Riou, Benoit; Lesourd, Mathieu; Brunel, Lionel; Versace, Rémy

    2011-08-01

    This study examined the relationship between memory and perception in order to identify the influence of a memory dimension in perceptual processing. Our aim was to determine whether the variation of typical size between items (i.e., the size in real life) affects visual search. In two experiments, the congruency between typical size difference and perceptual size difference was manipulated in a visual search task. We observed that congruency between the typical and perceptual size differences decreased reaction times in the visual search (Exp. 1), and noncongruency between these two differences increased reaction times in the visual search (Exp. 2). We argue that these results highlight that memory and perception share some resources and reveal the intervention of typical size difference on the computation of the perceptual size difference.

  18. Perceptions of restaurateurs on quality grading

    Directory of Open Access Journals (Sweden)

    Joseph Roberson

    2014-01-01

    Full Text Available A restaurateur's strategic focus is to maximise wealth for the owner(s. To achieve wealth maximisation, a restaurateur could implement one or more of the following strategies: focus strategy, cost-leadership strategy and/or differentiation strategy. A management intervention a restaurateur could implement to achieve this is quality differentiation. Grading of an establishment will assist a restaurateur in becoming a market leader. Currently there no national restaurant grading system exists in South Africa. As support and participation of restaurateurs in any future quality grading system are essential, it is imperative to test their perceptions of the implementation of a quality grading scale. The aim of this paper is to gather the perceptions of restaurateurs of an envisaged scale that could be used to grade independent full-service restaurants. In this study the researcher tested the perceptions of restaurateurs using nine possible outcomes of implementing quality grading in the independent fullservice restaurant segment. The outcomes to be tested were presented to restaurateurs in a questionnaire uploaded on "survey monkey". This was emailed to 3 286 restaurateurs and 265 responses were received. Respondents who were positive regarding grading indicated that they were enthusiastic about the impact grading would have on international tourism, as well as the fact that it could contribute to an increase in the value of their establishments.

  19. Visual working memory contaminates perception.

    Science.gov (United States)

    Kang, Min-Suk; Hong, Sang Wook; Blake, Randolph; Woodman, Geoffrey F

    2011-10-01

    Indirect evidence suggests that the contents of visual working memory may be maintained within sensory areas early in the visual hierarchy. We tested this possibility using a well-studied motion repulsion phenomenon in which perception of one direction of motion is distorted when another direction of motion is viewed simultaneously. We found that observers misperceived the actual direction of motion of a single motion stimulus if, while viewing that stimulus, they were holding a different motion direction in visual working memory. Control experiments showed that none of a variety of alternative explanations could account for this repulsion effect induced by working memory. Our findings provide compelling evidence that visual working memory representations directly interact with the same neural mechanisms as those involved in processing basic sensory events.

  20. Visual perception and radiographic interpretation

    International Nuclear Information System (INIS)

    Papageorges, M.

    1998-01-01

    Although interpretation errors are common in radiology, their causes are still debated. Perceptual mechanisms appear to be responsible for a large proportion of mistakes made by both neophytes and trained radiologists. Erroneous perception of familiar contours can be triggered by unrelated opacities. Conversely, visual information cannot induce a specific perception if the observer is not familiar with the concept represented or its radiographicappearance. Additionally, the area of acute vision is smaller than is commonly recognized. Other factors, such as the attitude, beliefs,.: preconceptions, and expectations of the viewer, can affect what he or she ''sees'' whenviewing any object, including a radiograph. Familiarity with perceptual mechanisms and the limitations of the visual system as well as multiple readings may be necessary to reduce interpretation errors

  1. Student Perceptions of Middle Grades Learning Environments

    Science.gov (United States)

    Wolsey, Thomas DeVere; Uline, Cynthia L.

    2010-01-01

    Researchers used student-generated photographs to mediate interviews with middle grades students about their school environment. Findings suggest that school leaders and facilities planners should be responsive to students' needs for both personal and social spaces and be aware of ways the built environment may shape the perceptions students hold…

  2. The hippocampus and visual perception

    Science.gov (United States)

    Lee, Andy C. H.; Yeung, Lok-Kin; Barense, Morgan D.

    2012-01-01

    In this review, we will discuss the idea that the hippocampus may be involved in both memory and perception, contrary to theories that posit functional and neuroanatomical segregation of these processes. This suggestion is based on a number of recent neuropsychological and functional neuroimaging studies that have demonstrated that the hippocampus is involved in the visual discrimination of complex spatial scene stimuli. We argue that these findings cannot be explained by long-term memory or working memory processing or, in the case of patient findings, dysfunction beyond the medial temporal lobe (MTL). Instead, these studies point toward a role for the hippocampus in higher-order spatial perception. We suggest that the hippocampus processes complex conjunctions of spatial features, and that it may be more appropriate to consider the representations for which this structure is critical, rather than the cognitive processes that it mediates. PMID:22529794

  3. The hippocampus and visual perception

    Directory of Open Access Journals (Sweden)

    Andy C. H. Lee

    2012-04-01

    Full Text Available In this review, we will discuss the idea that the hippocampus may be involved in both memory and perception, contrary to theories that posit functional and neuroanatomical segregation of these processes. This suggestion is based on a number of recent neuropsychological and functional neuroimaging studies that have demonstrated that the hippocampus is involved in the visual discrimination of complex spatial scene stimuli. We argue that these findings cannot be explained by long-term memory or working memory processing or, in the case of patient findings, dysfunction beyond the medial temporal lobe. Instead, these studies point towards a role for the hippocampus in higher-order spatial perception. We suggest that the hippocampus processes complex conjunctions of spatial features, and that it may be more appropriate to consider the representations for which this structure is critical, rather than the cognitive processes that it mediates.

  4. Making Information Visual: Seventh Grade Art Information and Visual Literacy

    Science.gov (United States)

    Shoemaker, Joel; Schau, Elizabeth; Ayers, Rachael

    2008-01-01

    Seventh grade students entering South East Junior High in Iowa City come from eight elementary feeder schools, as well as from schools around the world. Their information literacy skills and knowledge of reference sources vary, but since all seventh graders and new eighth graders are required to take one trimester of Visual Studies, all entering…

  5. Memory reactivation improves visual perception.

    Science.gov (United States)

    Amar-Halpert, Rotem; Laor-Maayany, Rony; Nemni, Shlomi; Rosenblatt, Jonathan D; Censor, Nitzan

    2017-10-01

    Human perception thresholds can improve through learning. Here we report findings challenging the fundamental 'practice makes perfect' basis of procedural learning theory, showing that brief reactivations of encoded visual memories are sufficient to improve perceptual discrimination thresholds. Learning was comparable to standard practice-induced learning and was not due to short training per se, nor to an epiphenomenon of primed retrieval enhancement. The results demonstrate that basic perceptual functions can be substantially improved by memory reactivation, supporting a new account of perceptual learning dynamics.

  6. Temporal constraints on visual perception

    DEFF Research Database (Denmark)

    Nielsen, Simon

    While the richness of our visual perceptions is nearly boundless, the rate with which we can perceive information is limited. For instance when we are required to perceive two consecutive target objects following briefly after each other, the accuracy with which we can report the second target...... is often reduced in the first half second. This phenomenon is known as the attentional blink (Raymond, Shapiro & Arnell, 1992) and as suggested by the name is assumed to pertain to how fast attention can be reallocated. Bottleneck models suggest that the attentional blink is caused by limited capacity...... in processing targets, which effectively causes a perceptual bottleneck (Chun & Potter, 1995). According to bottleneck models, making the first target easier to perceive should improve processing in the bottleneck and reduce the attentional blink. However, recent studies suggest that an attentional blink may...

  7. Visual perception of spatial subjects

    Energy Technology Data Exchange (ETDEWEB)

    Osterloh, K.R.S.; Ewert, U. [Federal Institute for Materials Research and Testing (BAM), Berlin (Germany)

    2007-07-01

    Principally, any imaging technology consists of two consecutive, though strictly separated processes: data acquisition and subsequent processing to generate an image that can be looked at, either on a monitor screen or printed on paper. Likewise, the physiological process of viewing can be separated into vision and perception, though these processes are much more overlapping. Understanding the appearance of a subject requires the entire sequence from receiving the information carried e.g. by photons up to an appropriate processing leading to the perception of the subject shown. As a consequence, the imagination of a subject is a result of both, technological and physiological processes. Whenever an evaluation of an image is critical, also the physiological part of the processing should be considered. However, an image has two dimensions in the first place and reality is spatial, it has three dimensions. This problem has been tackled on a philosophical level at least since Platon's famous discussion on the shadow image in a dark cave. The mere practical point is which structural details can be perceived and what may remain undetected depending on the mode of presentation. This problem cannot be resolved without considering each single step of visual perception. Physiologically, there are three 'tools' available to understanding the spatial structure of a subject: binocular viewing, following the course of perspective projection and motion to collect multiple aspects. Artificially, an object may be cut in various ways to display the interior or covering parts could be made transparent within a model. Samples will be shown how certain details of a subject can be emphasised or hidden depending on the way of presentation. It needs to be discussed what might help to perceive the true spatial structure of a subject with all relevant details and what could be misleading. (authors)

  8. Development of an automatic visual grading system for grafting seedlings

    Directory of Open Access Journals (Sweden)

    Subo Tian

    2017-01-01

    Full Text Available In this study, a visual grading system of vegetable grafting machine was developed. The study described key technology of visual grading system of vegetable grafting machine. First, the contrasting experiment was conducted between acquired images under blue background light and natural light conditions, with the blue background light chosen as lighting source. The Visual C++ platform with open-source computer vision library (Open CV was used for the image processing. Subsequently, maximum frequency of total number of 0-valued pixels was predicted and used to extract the measurements of scion and rootstock stem diameters. Finally, the developed integrated visual grading system was experimented with 100 scions and rootstock seedlings. The results showed that success rate of grading reached up to 98%. This shows that selection and grading of scion and rootstock could be fully automated with this developed visual grading system. Hence, this technology would be greatly helpful for improving the grading accuracy and efficiency.

  9. Os efeitos da idade na percepção visual de grades senoidais em luminância baixa The effects of age on visual perception of sine-wave gratings at low luminance

    Directory of Open Access Journals (Sweden)

    Natanael Antonio dos Santos

    2006-01-01

    Full Text Available O objetivo deste trabalho foi investigar a função de sensibilidade ao contraste (FSC de adultos e idosos (20-23, 30-39, 40-49, 50-59, 60-69 anos para grades senoidais de 0,25 a 2 cpg em luminância baixa. Todos os participantes apresentavam acuidade visual normal e se encontravam livres de doenças oculares identificáveis. Foram estimados limiares de contraste para 30 participantes (seis em cada faixa etária utilizando o método psicofísico da escolha forçada. Neste método, os participantes tinham que escolher um estímulo contendo uma freqüência de teste (grade senoidal em baixo contraste ou um estímulo neutro com luminância média de 0,7 cd/m². Os resultados mostraram que os grupos de 50-59 e 60-69 anos apresentaram prejuízos significativos na FSC nas freqüências espaciais de 1 e 2 cpg comparados ao grupo de 20-23 anos. Estes resultados sugerem alterações relacionadas à idade na FSC de freqüências espaciais em níveis baixos de luminância.The aim of this work was to investigate the contrast sensitivity function for sine-wave gratings in the range between 0.25-2 cpd in young and older adults (20-23, 30-39, 40-49, 50-59, 60-69 years old using low luminance. All subjects were free from identifiable ocular disease and had normal acuity. We measured the contrast thresholds for 30 participants (six volunteers in each age using the psychophysical forced-choice staircase method. In this method the volunteers had to choose the stimulus containing a test frequency at low contrast (e.g., a sine-wave grating, or another neutral stimulus at mean luminance (0.7 cd/m². The results showed significant changes of CSF for sine-wave gratings at 1 and 2 cpd for the adults 50-59 and 60-69 years old compared to the adults of 20-23 years old. These results suggest age-related changes in the CSF for sine-wave grating at low luminance levels.

  10. Neural pathways for visual speech perception

    Directory of Open Access Journals (Sweden)

    Lynne E Bernstein

    2014-12-01

    Full Text Available This paper examines the questions, what levels of speech can be perceived visually, and how is visual speech represented by the brain? Review of the literature leads to the conclusions that every level of psycholinguistic speech structure (i.e., phonetic features, phonemes, syllables, words, and prosody can be perceived visually, although individuals differ in their abilities to do so; and that there are visual modality-specific representations of speech qua speech in higher-level vision brain areas. That is, the visual system represents the modal patterns of visual speech. The suggestion that the auditory speech pathway receives and represents visual speech is examined in light of neuroimaging evidence on the auditory speech pathways. We outline the generally agreed-upon organization of the visual ventral and dorsal pathways and examine several types of visual processing that might be related to speech through those pathways, specifically, face and body, orthography, and sign language processing. In this context, we examine the visual speech processing literature, which reveals widespread diverse patterns activity in posterior temporal cortices in response to visual speech stimuli. We outline a model of the visual and auditory speech pathways and make several suggestions: (1 The visual perception of speech relies on visual pathway representations of speech qua speech. (2 A proposed site of these representations, the temporal visual speech area (TVSA has been demonstrated in posterior temporal cortex, ventral and posterior to multisensory posterior superior temporal sulcus (pSTS. (3 Given that visual speech has dynamic and configural features, its representations in feedforward visual pathways are expected to integrate these features, possibly in TVSA.

  11. Visual perception and medical imaging

    International Nuclear Information System (INIS)

    Jaffe, C.C.

    1985-01-01

    Medical imaging represents a particularly distinct discipline for image processing since it uniquely depends on the ''expert observer'' and yet models of the human visual system are totally inadequate at the complex level to allow satisfactory prediction of observer response to a given image modification. An illustration of the difficulties in assessing observer performance is shown by a series of optical illustrations which demonstrate that net cognitive behavior is not readily predictable. Although many of these phenomena are often considered as exceptional visual events, the setting of complex images makes it difficult to entirely exclude at least partial operation of these impairments during performance of the diagnostic medical imaging task

  12. Impact of coated windows on visual perception

    DEFF Research Database (Denmark)

    Johnsen, Kjeld; Dubois, Marie-Claude

    of a pilot study that investigated the impact of six coated glazings on daylight conditions in scale models. The study focused primarily on visual perception. Generally, the pilot study indicated that some types of coated glazings (especially solar protective coatings) significantly affect the perception......There is at present an architectural trend promoting the use of large glass facades in commercial and office buildings. These facades generate a large cooling and heating demand creating the need for combined solar-protective and low-emissitivity coated windows. This report describes the results...

  13. Gestalt perception modulates early visual processing.

    Science.gov (United States)

    Herrmann, C S; Bosch, V

    2001-04-17

    We examined whether early visual processing reflects perceptual properties of a stimulus in addition to physical features. We recorded event-related potentials (ERPs) of 13 subjects in a visual classification task. We used four different stimuli which were all composed of four identical elements. One of the stimuli constituted an illusory Kanizsa square, another was composed of the same number of collinear line segments but the elements did not form a Gestalt. In addition, a target and a control stimulus were used which were arranged differently. These stimuli allow us to differentiate the processing of colinear line elements (stimulus features) and illusory figures (perceptual properties). The visual N170 in response to the illusory figure was significantly larger as compared to the other collinear stimulus. This is taken to indicate that the visual N170 reflects cognitive processes of Gestalt perception in addition to attentional processes and physical stimulus properties.

  14. Perceptions of climate change among Grade 11 learners in the ...

    African Journals Online (AJOL)

    For this reason, the perceptions of climate change among high-school learners, who represent future decision-makers and stand as a proxy for the next generation, are of importance. This study was designed so as to gain insight into the nature of perceptions and associated determinants among Grade 11 learners in the ...

  15. Environmental Problem Perception of 6th Grade Students

    Science.gov (United States)

    Genc, Murat; Genc, Tulin; Ergenc, Mustafa; Erkuz, Neslihan

    2016-01-01

    This study aims to examine and compare the 6th grade students' perception of environmental issues through different techniques. For this purpose, we have tried to establish the students' perception of environmental issues by studying the pictures they drew and the written texts they wrote. In this study, where we have conducted with 62 students in…

  16. Visual-motor perception in students with attention deficit with hyperactivity disorder.

    Science.gov (United States)

    Germano, Giseli Donadon; Pinheiro, Fábio Henrique; Okuda, Paola Matiko Martins; Capellini, Simone Aparecida

    2013-01-01

    The aim of this study was to characterize and to compare the visual-motor perception of students with Attention Deficit with Hyperactivity Disorder (ADHD) with students with good academic performance. Forty students from 2nd to 5th grades of an elementary public school, male gender (100%), aged between 7 and 10 years and 8 months old participated, divided into: GI (20 students with ADHD) and GII (20 students with good academic performance), paired according to age, schooling and gender with GI. The students were submitted to Developmental Test of Visual Perception (DTVP-2). The students of GI presented low performance in spatial position and visual closure (reduced motor) and inferior age equivalent in reduced motor perception, when compared to GII. The difficulties in visual-motor perception presented by students of GI cannot be attributed to a primary deficit, but to a secondary phenomenon of inattention that interferes directly in their visual-motor performance.

  17. The function of stereotypes in visual perception.

    Science.gov (United States)

    Niemeyer, Greg O

    2003-01-01

    Human vision is a product of both physiological and cultural dispositions. This cultural study investigates the role of cultural dispositions in visual perception. In particular, the study focuses on the role of stereotypes, which are involved in recognition. I propose that stereotypes are essential for basic functions of perception and human perception. However, stereotypes also introduce significant limitations on human experience. The fact that stereotypes are abstract simplifications of realities is not the limiting factor, since scientific and cultural progress continually refines stereotypes. The very principle of the stereotype appears to introduce the limitation, because the process of forming stereotypes requires both temporal and functional fragmentations of the continuum of our perception. This fragmentation can be a cause of sensory overload, a postmodern condition that generates cultural, perceptual and behavioral problems. To address this problem, I propose a cultural modification to our modality of perception. The modification shifts the emphasis of our perception from the recognition of stereotypes to the recognition of flows, processes and durations. References to the work of Henri Bergson and Martin Heidegger provide the philosophical basis for this modification and several empirical and experimental examples illustrate such modifications in practice.

  18. Working memory can enhance unconscious visual perception.

    Science.gov (United States)

    Pan, Yi; Cheng, Qiu-Ping; Luo, Qian-Ying

    2012-06-01

    We demonstrate that unconscious processing of a stimulus property can be enhanced when there is a match between the contents of working memory and the stimulus presented in the visual field. Participants first held a cue (a colored circle) in working memory and then searched for a brief masked target shape presented simultaneously with a distractor shape. When participants reported having no awareness of the target shape at all, search performance was more accurate in the valid condition, where the target matched the cue in color, than in the neutral condition, where the target mismatched the cue. This effect cannot be attributed to bottom-up perceptual priming from the presentation of a memory cue, because unconscious perception was not enhanced when the cue was merely perceptually identified but not actively held in working memory. These findings suggest that reentrant feedback from the contents of working memory modulates unconscious visual perception.

  19. Ninth Grade Student Attendance: Teacher Perceptional Study

    Science.gov (United States)

    Caldwell, Barbara A.

    2010-01-01

    Excessive student absenteeism among ninth graders was a major problem within a metropolitan Georgia high school. In order to solve the attendance problem and several other academic concerns, the school administration implemented a smaller learning community for ninth grade students. The Ninth Grade Academy concept implemented at the beginning of…

  20. Separate visual representations for perception and for visually guided behavior

    Science.gov (United States)

    Bridgeman, Bruce

    1989-01-01

    Converging evidence from several sources indicates that two distinct representations of visual space mediate perception and visually guided behavior, respectively. The two maps of visual space follow different rules; spatial values in either one can be biased without affecting the other. Ordinarily the two maps give equivalent responses because both are veridically in register with the world; special techniques are required to pull them apart. One such technique is saccadic suppression: small target displacements during saccadic eye movements are not preceived, though the displacements can change eye movements or pointing to the target. A second way to separate cognitive and motor-oriented maps is with induced motion: a slowly moving frame will make a fixed target appear to drift in the opposite direction, while motor behavior toward the target is unchanged. The same result occurs with stroboscopic induced motion, where the frame jump abruptly and the target seems to jump in the opposite direction. A third method of separating cognitive and motor maps, requiring no motion of target, background or eye, is the Roelofs effect: a target surrounded by an off-center rectangular frame will appear to be off-center in the direction opposite the frame. Again the effect influences perception, but in half of the subjects it does not influence pointing to the target. This experience also reveals more characteristics of the maps and their interactions with one another, the motor map apparently has little or no memory, and must be fed from the biased cognitive map if an enforced delay occurs between stimulus presentation and motor response. In designing spatial displays, the results mean that what you see isn't necessarily what you get. Displays must be designed with either perception or visually guided behavior in mind.

  1. Visual perception of materials and their properties.

    Science.gov (United States)

    Fleming, Roland W

    2014-01-01

    Misidentifying materials-such as mistaking soap for pâté, or vice versa-could lead to some pretty messy mishaps. Fortunately, we rarely suffer such indignities, thanks largely to our outstanding ability to recognize materials-and identify their properties-by sight. In everyday life, we encounter an enormous variety of materials, which we usually distinguish effortlessly and without error. However, despite its subjective ease, material perception poses the visual system with some unique and significant challenges, because a given material can take on many different appearances depending on the lighting, viewpoint and shape. Here, I use observations from recent research on material perception to outline a general theory of material perception, in which I suggest that the visual system does not actually estimate physical parameters of materials and objects. Instead-I argue-the brain is remarkably adept at building 'statistical generative models' that capture the natural degrees of variation in appearance between samples. For example, when determining perceived glossiness, the brain does not estimate parameters of the BRDF. Instead, it uses a constellation of low- and mid-level image measurements to characterize the extent to which the surface manifests specular reflections. I argue that these 'statistical appearance models' are both more expressive and easier to compute than physical parameters, and therefore represent a powerful middle way between a 'bag of tricks' and 'inverse optics'. Copyright © 2013 The Author. Published by Elsevier Ltd.. All rights reserved.

  2. Towards computer-based perception by modeling visual perception : A probalistic theory

    NARCIS (Netherlands)

    Ciftcioglu, O.; Bittermann, M.; Sariyildiz, S.

    2006-01-01

    Studies on computer-based perception by vision modelling are described. The visual perception is mathematically modelled where the model receives and interprets visual data from the environment. The perception is defined in probabilistic terms so that it is in the same way quantified. Human visual

  3. Visual body perception in anorexia nervosa.

    Science.gov (United States)

    Urgesi, Cosimo; Fornasari, Livia; Perini, Laura; Canalaz, Francesca; Cremaschi, Silvana; Faleschini, Laura; Balestrieri, Matteo; Fabbro, Franco; Aglioti, Salvatore Maria; Brambilla, Paolo

    2012-05-01

    Disturbance of body perception is a central aspect of anorexia nervosa (AN) and several neuroimaging studies have documented structural and functional alterations of occipito-temporal cortices involved in visual body processing. However, it is unclear whether these perceptual deficits involve more basic aspects of others' body perception. A consecutive sample of 15 adolescent patients with AN were compared with a group of 15 age- and gender-matched controls in delayed matching to sample tasks requiring the visual discrimination of the form or of the action of others' body. Patients showed better visual discrimination performance than controls in detail-based processing of body forms but not of body actions, which positively correlated with their increased tendency to convert a signal of punishment into a signal of reinforcement (higher persistence scores). The paradoxical advantage of patients with AN in detail-based body processing may be associated to their tendency to routinely explore body parts as a consequence of their obsessive worries about body appearance. Copyright © 2012 Wiley Periodicals, Inc.

  4. Cross-cultural differences in visual perception

    Directory of Open Access Journals (Sweden)

    Jiří Čeněk

    2015-09-01

    Full Text Available According to recent cross-cultural studies there exist culturally based differences between visual perception and the related cognitive processes (attention, memory. According to current research, East Asians and Westerners percieve and think about the world in very different ways. Westerners are inclined to attend to some focal object (a salient object within a perception field that is relatively big in size, fast moving, colourful focusing on and analyzing its attributes. East Asians on the other hand are more likely to attend to a broad perceptual field, noticing relationships and changes. In this paper we want to describe the recent findings in the field and propose some directions for future research.

  5. Visual monitoring of railroad grade crossing

    Science.gov (United States)

    Sheikh, Yaser A.; Zhai, Yun; Shafique, Khurram; Shah, Mubarak A.

    2004-09-01

    There are approximately 261,000 rail crossings in the United States according to the studies by the National Highway Traffic Safety Administration (NHTSA) and Federal Railroad Administration (FRA). From 1993 to 1998, there were over 25,000 highway-rail crossing incidents involving motor vehicles - averaging 4,167 incidents a year. In this paper, we present a real-time computer vision system for the monitoring of the movement of pedestrians, bikers, animals and vehicles at railroad intersections. The video is processed for the detection of uncharacteristic events, triggering an immediate warning system. In order to recognize the events, the system first performs robust object detection and tracking. Next, a classification algorithm is used to determine whether the detected object is a pedestrian, biker, group or a vehicle, allowing inferences on whether the behavior of the object is characteristic or not. Due to the ubiquity of low cost, low power, and high quality video cameras, increased computing power and memory capacity, the proposed approach provides a cost effective and scalable solution to this important problem. Furthermore, the system has the potential to significantly decrease the number of accidents and therefore the resulting deaths and injuries that occur at railroad crossings. We have field tested our system at two sites, a rail-highway grade crossing, and a trestle located in Central Florida, and we present results on six hours of collected data.

  6. The Ethereal Veil of Visual Perception

    Directory of Open Access Journals (Sweden)

    Gert J. Van Tonder

    2011-05-01

    Full Text Available The rich palette of perceptual effects elicited from simple patterns of black and white lines—such as the paintings of op artists—underlines just how much science still needs to unravel before the complexity of visual perception is fully understood. In this presentation, I would like to show how a few of the more subtle and some of the most salient perceptual effects experienced in black and white line patterns can be interpreted as a concerted outcome of various very early stages of visual processing. Specifically, what seem to be complex effects can be simulated with relatively simple models. The effects bear witness to the intuitive skill with which the artists wield considerable visual impact on their canvas. Scientific scrutiny, of their art and of the possible visual processing involved, leads to new insight into the perceptual complexity experienced in these deceptively simple paintings. In a sense, their works present the construction of an ephemeral canvas within stripes of black and white paint.

  7. Seventh Grade Students and the Visual Messages They Love

    Science.gov (United States)

    De Abreu, Belinha

    2008-01-01

    Most seventh grade students partially define themselves through everyday media messages. As a part of understanding how these images and the media impacts their lives, the author collaborated with her colleagues to develop a unit to help teens learn how visual messages such as those in pictures, media icons, logos, slogans, clothing, toys, and…

  8. The role of human ventral visual cortex in motion perception

    Science.gov (United States)

    Saygin, Ayse P.; Lorenzi, Lauren J.; Egan, Ryan; Rees, Geraint; Behrmann, Marlene

    2013-01-01

    Visual motion perception is fundamental to many aspects of visual perception. Visual motion perception has long been associated with the dorsal (parietal) pathway and the involvement of the ventral ‘form’ (temporal) visual pathway has not been considered critical for normal motion perception. Here, we evaluated this view by examining whether circumscribed damage to ventral visual cortex impaired motion perception. The perception of motion in basic, non-form tasks (motion coherence and motion detection) and complex structure-from-motion, for a wide range of motion speeds, all centrally displayed, was assessed in five patients with a circumscribed lesion to either the right or left ventral visual pathway. Patients with a right, but not with a left, ventral visual lesion displayed widespread impairments in central motion perception even for non-form motion, for both slow and for fast speeds, and this held true independent of the integrity of areas MT/V5, V3A or parietal regions. In contrast with the traditional view in which only the dorsal visual stream is critical for motion perception, these novel findings implicate a more distributed circuit in which the integrity of the right ventral visual pathway is also necessary even for the perception of non-form motion. PMID:23983030

  9. Hand-crafted programming objects and visual perception

    CSIR Research Space (South Africa)

    Smith, Andrew C

    2009-05-01

    Full Text Available literacy obstacle. Good visual perceptual skills is one of the requirements to be a successful tangible programmer. A quantitative test developed for measuring certain aspects of visual perception skills as appropriate to tangible programming is presented...

  10. College Students' Categorical Perceptions of Grades: It's Simply "Good" vs. "Bad"

    Science.gov (United States)

    Boatright-Horowitz, Su L.; Arruda, Chris

    2013-01-01

    College students' categorical perceptions of numeric and alphabetic grades were examined by assigning participants to one of four conditions: numeric grades alphabetic grades, numeric non-grades and alphabetic non-grades. They were then asked to give ratings for each possible grade or non-grade, using a 10-point scale. Factor analysis revealed…

  11. Neural mechanisms underlying temporal modulation of visual perception

    NARCIS (Netherlands)

    Jong, M.C. de

    2015-01-01

    However confident we feel about the way we perceive the visual world around us, there is not a one-to-one relation between visual stimulation and visual perception. Our eyes register reflections of the visual environment and our brain has the difficult task of constructing ‘reality’ from this

  12. Neurocomputational account of memory and perception: Thresholded and graded signals in the hippocampus.

    Science.gov (United States)

    Elfman, Kane W; Aly, Mariam; Yonelinas, Andrew P

    2014-12-01

    Recent evidence suggests that the hippocampus, a region critical for long-term memory, also supports certain forms of high-level visual perception. A seemingly paradoxical finding is that, unlike the thresholded hippocampal signals associated with memory, the hippocampus produces graded, strength-based signals in perception. This article tests a neurocomputational model of the hippocampus, based on the complementary learning systems framework, to determine if the same model can account for both memory and perception, and whether it produces the appropriate thresholded and strength-based signals in these two types of tasks. The simulations showed that the hippocampus, and most prominently the CA1 subfield, produced graded signals when required to discriminate between highly similar stimuli in a perception task, but generated thresholded patterns of activity in recognition memory. A threshold was observed in recognition memory because pattern completion occurred for only some trials and completely failed to occur for others; conversely, in perception, pattern completion always occurred because of the high degree of item similarity. These results offer a neurocomputational account of the distinct hippocampal signals associated with perception and memory, and are broadly consistent with proposals that CA1 functions as a comparator of expected versus perceived events. We conclude that the hippocampal computations required for high-level perceptual discrimination are congruous with current neurocomputational models that account for recognition memory, and fit neatly into a broader description of the role of the hippocampus for the processing of complex relational information. © 2014 Wiley Periodicals, Inc.

  13. Cortical visual prostheses: from microstimulation to functional percept

    Science.gov (United States)

    Najarpour Foroushani, Armin; Pack, Christopher C.; Sawan, Mohamad

    2018-04-01

    Cortical visual prostheses are intended to restore vision by targeted electrical stimulation of the visual cortex. The perception of spots of light, called phosphenes, resulting from microstimulation of the visual pathway, suggests the possibility of creating meaningful percept made of phosphenes. However, to date electrical stimulation of V1 has still not resulted in perception of phosphenated images that goes beyond punctate spots of light. In this review, we summarize the clinical and experimental progress that has been made in generating phosphenes and modulating their associated perceptual characteristics in human and macaque primary visual cortex (V1). We focus specifically on the effects of different microstimulation parameters on perception and we analyse key challenges facing the generation of meaningful artificial percepts. Finally, we propose solutions to these challenges based on the application of supervised learning of population codes for spatial stimulation of visual cortex.

  14. Visual perception of axes of head rotation

    Directory of Open Access Journals (Sweden)

    David Mattijs Arnoldussen

    2013-02-01

    Full Text Available Registration of ego-motion is important to accurately navigate through space. Movements of the head and eye relative to space are registered through the vestibular system and optical flow, respectively. Here, we address three questions concerning the visual registration of self-rotation. 1. Eye-in-head movements provide a link between the motion signals received by sensors in the moving eye and sensors in the moving head. How are these signals combined into an ego-rotation percept? We combined optic flow of simulated forward and rotational motion of the eye with different levels of eye-in-head rotation for a stationary head. We dissociated simulated gaze rotation and head rotation by different levels of eye-in-head pursuit.We found that perceived rotation matches simulated head- not gaze-rotation. This rejects a model for perceived self-rotation that relies on the rotation of the gaze line. Rather, eye-in-head signals serve to transform the optic flow’s rotation information, that specifies rotation of the scene relative to the eye, into a rotation relative to the head. This suggests that transformed visual self-rotation signals may combine with vestibular signals.2. Do transformed visual self-rotation signals reflect the arrangement of the semicircular canals (SCC? Previously, we found sub-regions within MST and V6+ that respond to the speed of the simulated head rotation. Here, we re-analyzed those BOLD signals for the presence of a spatial dissociation related to the axes of visually simulated head rotation, such as have been found in sub-cortical regions of various animals. Contrary, we found a rather uniform BOLD response to simulated rotation along the three SCC axes.3. We investigated if subject’s sensitivity to the direction of the head rotation axis shows SCC axes specifcity. We found that sensitivity to head rotation is rather uniformly distributed, suggesting that in human cortex, visuo-vestibular integration is not arranged into

  15. Visual perception of axes of head rotation

    Science.gov (United States)

    Arnoldussen, D. M.; Goossens, J.; van den Berg, A. V.

    2013-01-01

    Registration of ego-motion is important to accurately navigate through space. Movements of the head and eye relative to space are registered through the vestibular system and optical flow, respectively. Here, we address three questions concerning the visual registration of self-rotation. (1) Eye-in-head movements provide a link between the motion signals received by sensors in the moving eye and sensors in the moving head. How are these signals combined into an ego-rotation percept? We combined optic flow of simulated forward and rotational motion of the eye with different levels of eye-in-head rotation for a stationary head. We dissociated simulated gaze rotation and head rotation by different levels of eye-in-head pursuit. We found that perceived rotation matches simulated head- not gaze-rotation. This rejects a model for perceived self-rotation that relies on the rotation of the gaze line. Rather, eye-in-head signals serve to transform the optic flow's rotation information, that specifies rotation of the scene relative to the eye, into a rotation relative to the head. This suggests that transformed visual self-rotation signals may combine with vestibular signals. (2) Do transformed visual self-rotation signals reflect the arrangement of the semi-circular canals (SCC)? Previously, we found sub-regions within MST and V6+ that respond to the speed of the simulated head rotation. Here, we re-analyzed those Blood oxygenated level-dependent (BOLD) signals for the presence of a spatial dissociation related to the axes of visually simulated head rotation, such as have been found in sub-cortical regions of various animals. Contrary, we found a rather uniform BOLD response to simulated rotation along the three SCC axes. (3) We investigated if subject's sensitivity to the direction of the head rotation axis shows SCC axes specifcity. We found that sensitivity to head rotation is rather uniformly distributed, suggesting that in human cortex, visuo-vestibular integration is

  16. S3-1: The Serial Dependence of Visual Perception

    Directory of Open Access Journals (Sweden)

    David Whitney

    2012-10-01

    Full Text Available In our moment-to-moment perceptual experience, visual scenes can change, but objects rarely spontaneously come into or out of existence. The visual system may therefore delicately balance the need to optimize sensitivity to image changes (e.g., by adapting to changes in color, orientation, object identity, etc with the desire to represent the temporal continuity of objects—the likelihood that objects perceived at this moment tend to exist in subsequent moments. One way that the visual system may promote such stability is through the introduction of serial dependence to visual perception: by biasing the current percept toward what was seen at previous moments, the brain could compensate for variability in visual input that might otherwise disrupt perceptual continuity. Here, in two sets of experiments, we tested for serial dependence in visual perception of orientation and facial expression. We found that on a given trial, a subject's perception of the orientation of a grating reflected not only the currently viewed stimulus, but also a systematic attraction toward the orientations of the previously viewed stimuli. We found the same serial dependence in the perception of facial expression. This perceptual attraction extended over several trials and seconds, and displayed clear tuning to the difference (in orientation or facial expression between the sequential stimuli. Furthermore, serial dependence in object perception was spatially specific and selective to the attended object within a scene. Several control experiments showed that the perceptual serial dependence we report cannot be explained by effects of priming, known hysteresis effects, visual short-term memory, or expectation. Our results reveal a systematic influence of recent visual experiences on perception at any given moment: visual percepts, even of unambiguous stimuli, are attracted toward what was previously seen. We propose that such serial dependence helps to maintain

  17. Behavioral model of visual perception and recognition

    Science.gov (United States)

    Rybak, Ilya A.; Golovan, Alexander V.; Gusakova, Valentina I.

    1993-09-01

    In the processes of visual perception and recognition human eyes actively select essential information by way of successive fixations at the most informative points of the image. A behavioral program defining a scanpath of the image is formed at the stage of learning (object memorizing) and consists of sequential motor actions, which are shifts of attention from one to another point of fixation, and sensory signals expected to arrive in response to each shift of attention. In the modern view of the problem, invariant object recognition is provided by the following: (1) separated processing of `what' (object features) and `where' (spatial features) information at high levels of the visual system; (2) mechanisms of visual attention using `where' information; (3) representation of `what' information in an object-based frame of reference (OFR). However, most recent models of vision based on OFR have demonstrated the ability of invariant recognition of only simple objects like letters or binary objects without background, i.e. objects to which a frame of reference is easily attached. In contrast, we use not OFR, but a feature-based frame of reference (FFR), connected with the basic feature (edge) at the fixation point. This has provided for our model, the ability for invariant representation of complex objects in gray-level images, but demands realization of behavioral aspects of vision described above. The developed model contains a neural network subsystem of low-level vision which extracts a set of primary features (edges) in each fixation, and high- level subsystem consisting of `what' (Sensory Memory) and `where' (Motor Memory) modules. The resolution of primary features extraction decreases with distances from the point of fixation. FFR provides both the invariant representation of object features in Sensor Memory and shifts of attention in Motor Memory. Object recognition consists in successive recall (from Motor Memory) and execution of shifts of attention and

  18. Working memory biasing of visual perception without awareness.

    Science.gov (United States)

    Pan, Yi; Lin, Bingyuan; Zhao, Yajun; Soto, David

    2014-10-01

    Previous research has demonstrated that the contents of visual working memory can bias visual processing in favor of matching stimuli in the scene. However, the extent to which such top-down, memory-driven biasing of visual perception is contingent on conscious awareness remains unknown. Here we showed that conscious awareness of critical visual cues is dispensable for working memory to bias perceptual selection mechanisms. Using the procedure of continuous flash suppression, we demonstrated that "unseen" visual stimuli during interocular suppression can gain preferential access to awareness if they match the contents of visual working memory. Strikingly, the very same effect occurred even when the visual cue to be held in memory was rendered nonconscious by masking. Control experiments ruled out the alternative accounts of repetition priming and different detection criteria. We conclude that working memory biases of visual perception can operate in the absence of conscious awareness.

  19. Visual application of the American Board of Orthodontics Grading System.

    Science.gov (United States)

    Scott, Steven A; Freer, Terry J

    2005-05-01

    Assessment of treatment outcomes has traditionally been accomplished using the subjective opinion of experienced clinicians. Reduced subjectivity in the assessment of orthodontic treatment can be achieved with the use of an occlusal index. To implement an index for quality assurance purposes is time-consuming and subject to the inherent error of the index. Quality assessment of orthodontic treatment on a routine basis has been difficult to implement in private practice. To investigate whether a clinician can accurately apply the American Board of Orthodontics Objective Grading System by direct visual inspection instead of measuring individual traits. A random sample of 30 cases was selected, including pretreatment and post-treatment upper and lower study casts and panoramic radiographs. The cases were examined and scored with the standardized measuring gauge according to the protocol provided by the American Board of Orthodontics (ABO). The records were re-examined 6 weeks later and the individual traits scored by visual inspection (VI). There were no significant differences between the pre- and post-treatment ABO gauge and VI scores. This study suggests that occlusal traits defined by the ABO Objective Grading System can be accurately assessed by visual inspection. The VI score provides a simple and convenient method for critical evaluation of treatment outcome by a clinician.

  20. Contrast and Strength of Visual Memory and Imagery Differentially Affect Visual Perception

    OpenAIRE

    Saad, Elyana; Silvanto, Juha

    2013-01-01

    Visual short-term memory (VSTM) and visual imagery have been shown to modulate visual perception. However, how the subjective experience of VSTM/imagery and its contrast modulate this process has not been investigated. We addressed this issue by asking participants to detect brief masked targets while they were engaged either in VSTM or visual imagery. Subjective experience of memory/imagery (strength scale), and the visual contrast of the memory/mental image (contrast scale) were assessed on...

  1. The role of visual spatial attention in audiovisual speech perception

    DEFF Research Database (Denmark)

    Andersen, Tobias; Tiippana, K.; Laarni, J.

    2009-01-01

    Auditory and visual information is integrated when perceiving speech, as evidenced by the McGurk effect in which viewing an incongruent talking face categorically alters auditory speech perception. Audiovisual integration in speech perception has long been considered automatic and pre......-attentive but recent reports have challenged this view. Here we study the effect of visual spatial attention on the McGurk effect. By presenting a movie of two faces symmetrically displaced to each side of a central fixation point and dubbed with a single auditory speech track, we were able to discern the influences...... from each of the faces and from the voice on the auditory speech percept. We found that directing visual spatial attention towards a face increased the influence of that face on auditory perception. However, the influence of the voice on auditory perception did not change suggesting that audiovisual...

  2. Sustained Rhythmic Brain Activity Underlies Visual Motion Perception in Zebrafish

    Directory of Open Access Journals (Sweden)

    Verónica Pérez-Schuster

    2016-10-01

    Full Text Available Following moving visual stimuli (conditioning stimuli, CS, many organisms perceive, in the absence of physical stimuli, illusory motion in the opposite direction. This phenomenon is known as the motion aftereffect (MAE. Here, we use MAE as a tool to study the neuronal basis of visual motion perception in zebrafish larvae. Using zebrafish eye movements as an indicator of visual motion perception, we find that larvae perceive MAE. Blocking eye movements using optogenetics during CS presentation did not affect MAE, but tectal ablation significantly weakened it. Using two-photon calcium imaging of behaving GCaMP3 larvae, we find post-stimulation sustained rhythmic activity among direction-selective tectal neurons associated with the perception of MAE. In addition, tectal neurons tuned to the CS direction habituated, but neurons in the retina did not. Finally, a model based on competition between direction-selective neurons reproduced MAE, suggesting a neuronal circuit capable of generating perception of visual motion.

  3. Visual perception and imagery: a new molecular hypothesis.

    Science.gov (United States)

    Bókkon, I

    2009-05-01

    Here, we put forward a redox molecular hypothesis about the natural biophysical substrate of visual perception and visual imagery. This hypothesis is based on the redox and bioluminescent processes of neuronal cells in retinotopically organized cytochrome oxidase-rich visual areas. Our hypothesis is in line with the functional roles of reactive oxygen and nitrogen species in living cells that are not part of haphazard process, but rather a very strict mechanism used in signaling pathways. We point out that there is a direct relationship between neuronal activity and the biophoton emission process in the brain. Electrical and biochemical processes in the brain represent sensory information from the external world. During encoding or retrieval of information, electrical signals of neurons can be converted into synchronized biophoton signals by bioluminescent radical and non-radical processes. Therefore, information in the brain appears not only as an electrical (chemical) signal but also as a regulated biophoton (weak optical) signal inside neurons. During visual perception, the topological distribution of photon stimuli on the retina is represented by electrical neuronal activity in retinotopically organized visual areas. These retinotopic electrical signals in visual neurons can be converted into synchronized biophoton signals by radical and non-radical processes in retinotopically organized mitochondria-rich areas. As a result, regulated bioluminescent biophotons can create intrinsic pictures (depictive representation) in retinotopically organized cytochrome oxidase-rich visual areas during visual imagery and visual perception. The long-term visual memory is interpreted as epigenetic information regulated by free radicals and redox processes. This hypothesis does not claim to solve the secret of consciousness, but proposes that the evolution of higher levels of complexity made the intrinsic picture representation of the external visual world possible by regulated

  4. Visual perception of ADHD children with sensory processing disorder.

    Science.gov (United States)

    Jung, Hyerim; Woo, Young Jae; Kang, Je Wook; Choi, Yeon Woo; Kim, Kyeong Mi

    2014-04-01

    The aim of the present study was to investigate the visual perception difference between ADHD children with and without sensory processing disorder, and the relationship between sensory processing and visual perception of the children with ADHD. Participants were 47 outpatients, aged 6-8 years, diagnosed with ADHD. After excluding those who met exclusion criteria, 38 subjects were clustered into two groups, ADHD children with and without sensory processing disorder (SPD), using SSP reported by their parents, then subjects completed K-DTVP-2. Spearman correlation analysis was run to determine the relationship between sensory processing and visual perception, and Mann-Whitney-U test was conducted to compare the K-DTVP-2 score of two groups respectively. The ADHD children with SPD performed inferiorly to ADHD children without SPD in the on 3 quotients of K-DTVP-2. The GVP of K-DTVP-2 score was related to Movement Sensitivity section (r=0.368(*)) and Low Energy/Weak section of SSP (r=0.369*). The result of the present study suggests that among children with ADHD, the visual perception is lower in those children with co-morbid SPD. Also, visual perception may be related to sensory processing, especially in the reactions of vestibular and proprioceptive senses. Regarding academic performance, it is necessary to consider how sensory processing issues affect visual perception in children with ADHD.

  5. A Dynamic Systems Theory Model of Visual Perception Development

    Science.gov (United States)

    Coté, Carol A.

    2015-01-01

    This article presents a model for understanding the development of visual perception from a dynamic systems theory perspective. It contrasts to a hierarchical or reductionist model that is often found in the occupational therapy literature. In this proposed model vision and ocular motor abilities are not foundational to perception, they are seen…

  6. Motor-independent Visual Perception Skill Indexes are Related with Reading Skills in Children with Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Vahid Reza Khodabandeh

    2015-10-01

    Full Text Available Objective: Cerebral palsy is one of the most common causes of physical disability in childhood that lead to various difficulties for children. These children may have abnormalities in visual perception. Visual perception plays an important role in learning of basic childhood’s skills. This research was designed to study the relation between each of subtests of visual perception with accuracy and speed components of reading skills in school-aged cerebral palsy children. Materials & Methods: In this cross-sectional study, 24 spastic cerebral palsy students in second grade (10 girls and 14 boy were selected be available as from Tehran’s rehabilitation clinics. Visual perception and Reading skills were evaluated with the Test of Visual Perceptual Skill-revised (TVPS-R and Diagnostic Reading Test. Results: The results showed that between standard score of visual perception with accuracy and speed components of reading skills of cerebral palsy student were significantly correlated. Visual Discrimination with accuracy (P<0.001 and with speed (P<0.001, Visual Memory with accuracy  (P=0.002 and with speed (P=0.004, Visual-Spatial with accuracy (P<0.001 and with speed (P<0.001, Form Constancy with accuracy (P=0.003 and with speed (p<0.001, Visual Sequential Memory with accuracy (P=0.023 and with speed (P<0.028, Figure Ground Discrimination with accuracy (P=0.010 and with speed (P<0.011, Visual Closure with accuracy (p=0.009 and with speed (P<0.009 Conclusion: In general we can say that the relationship between visual perception skills with reading skills in first and second grade students with cerebral palsy is evident.

  7. Public health nurse perceptions of Omaha System data visualization.

    Science.gov (United States)

    Lee, Seonah; Kim, Era; Monsen, Karen A

    2015-10-01

    Electronic health records (EHRs) provide many benefits related to the storage, deployment, and retrieval of large amounts of patient data. However, EHRs have not fully met the need to reuse data for decision making on follow-up care plans. Visualization offers new ways to present health data, especially in EHRs. Well-designed data visualization allows clinicians to communicate information efficiently and effectively, contributing to improved interpretation of clinical data and better patient care monitoring and decision making. Public health nurse (PHN) perceptions of Omaha System data visualization prototypes for use in EHRs have not been evaluated. To visualize PHN-generated Omaha System data and assess PHN perceptions regarding the visual validity, helpfulness, usefulness, and importance of the visualizations, including interactive functionality. Time-oriented visualization for problems and outcomes and Matrix visualization for problems and interventions were developed using PHN-generated Omaha System data to help PHNs consume data and plan care at the point of care. Eleven PHNs evaluated prototype visualizations. Overall PHNs response to visualizations was positive, and feedback for improvement was provided. This study demonstrated the potential for using visualization techniques within EHRs to summarize Omaha System patient data for clinicians. Further research is needed to improve and refine these visualizations and assess the potential to incorporate visualizations within clinical EHRs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  8. Graded Neuronal Modulations Related to Visual Spatial Attention

    Science.gov (United States)

    Maunsell, John H. R.

    2016-01-01

    Studies of visual attention in monkeys typically measure neuronal activity when the stimulus event to be detected occurs at a cued location versus when it occurs at an uncued location. But this approach does not address how neuronal activity changes relative to conditions where attention is unconstrained by cueing. Human psychophysical studies have used neutral cueing conditions and found that neutrally cued behavioral performance is generally intermediate to that of cued and uncued conditions (Posner et al., 1978; Mangun and Hillyard, 1990; Montagna et al., 2009). To determine whether the neuronal correlates of visual attention during neutral cueing are similarly intermediate, we trained macaque monkeys to detect changes in stimulus orientation that were more likely to occur at one location (cued) than another (uncued), or were equally likely to occur at either stimulus location (neutral). Consistent with human studies, performance was best when the location was cued, intermediate when both locations were neutrally cued, and worst when the location was uncued. Neuronal modulations in visual area V4 were also graded as a function of cue validity and behavioral performance. By recording from both hemispheres simultaneously, we investigated the possibility of switching attention between stimulus locations during neutral cueing. The results failed to support a unitary “spotlight” of attention. Overall, our findings indicate that attention-related changes in V4 are graded to accommodate task demands. SIGNIFICANCE STATEMENT Studies of the neuronal correlates of attention in monkeys typically use visual cues to manipulate where attention is focused (“cued” vs “uncued”). Human psychophysical studies often also include neutrally cued trials to study how attention naturally varies between points of interest. But the neuronal correlates of this neutral condition are unclear. We measured behavioral performance and neuronal activity in cued, uncued, and neutrally

  9. From humans to computers cognition through visual perception

    CERN Document Server

    Alexandrov, Viktor Vasilievitch

    1991-01-01

    This book considers computer vision to be an integral part of the artificial intelligence system. The core of the book is an analysis of possible approaches to the creation of artificial vision systems, which simulate human visual perception. Much attention is paid to the latest achievements in visual psychology and physiology, the description of the functional and structural organization of the human perception mechanism, the peculiarities of artistic perception and the expression of reality. Computer vision models based on these data are investigated. They include the processes of external d

  10. Image Visual Realism: From Human Perception to Machine Computation.

    Science.gov (United States)

    Fan, Shaojing; Ng, Tian-Tsong; Koenig, Bryan L; Herberg, Jonathan S; Jiang, Ming; Shen, Zhiqi; Zhao, Qi

    2017-08-30

    Visual realism is defined as the extent to which an image appears to people as a photo rather than computer generated. Assessing visual realism is important in applications like computer graphics rendering and photo retouching. However, current realism evaluation approaches use either labor-intensive human judgments or automated algorithms largely dependent on comparing renderings to reference images. We develop a reference-free computational framework for visual realism prediction to overcome these constraints. First, we construct a benchmark dataset of 2520 images with comprehensive human annotated attributes. From statistical modeling on this data, we identify image attributes most relevant for visual realism. We propose both empirically-based (guided by our statistical modeling of human data) and CNN-learned features to predict visual realism of images. Our framework has the following advantages: (1) it creates an interpretable and concise empirical model that characterizes human perception of visual realism; (2) it links computational features to latent factors of human image perception.

  11. Individual differences in visual perception and memory

    NARCIS (Netherlands)

    Colizoli, O.

    2014-01-01

    There is substantial variation in perception and memory in humans. There are individuals who cannot see red at all, and there are individuals who hear colors and taste words. What determines the differences and similarities between individuals' perception and memory? Can we characterize the neural

  12. Visual-vestibular interaction in motion perception

    NARCIS (Netherlands)

    Hosman, Ruud J A W; Cardullo, Frank M.; Bos, Jelte E.

    2011-01-01

    Correct perception of self motion is of vital importance for both the control of our position and posture when moving around in our environment. With the development of human controlled vehicles as bicycles, cars and aircraft motion perception became of interest for the understanding of vehicle

  13. Neuroimaging of person perception: A social-visual interface.

    Science.gov (United States)

    Brooks, Jeffrey A; Freeman, Jonathan B

    2017-12-21

    The visual system is able to extract an enormous amount of socially relevant information from the face, including social categories, personality traits, and emotion. While facial features may be directly tied to certain perceptions, emerging research suggests that top-down social cognitive factors (e.g., stereotypes, social-conceptual knowledge, prejudice) considerably influence and shape the perceptual process. The rapid integration of higher-order social cognitive processes into visual perception can give rise to systematic biases in face perception and may potentially act as a mediating factor for intergroup behavioral and evaluative biases. Drawing on neuroimaging evidence, we review the ways that top-down social cognitive factors shape visual perception of facial features. This emerging work in social and affective neuroscience builds upon work on predictive coding and perceptual priors in cognitive neuroscience and visual cognition, suggesting domain-general mechanisms that underlie a social-visual interface through which social cognition affects visual perception. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Relating Standardized Visual Perception Measures to Simulator Visual System Performance

    Science.gov (United States)

    Kaiser, Mary K.; Sweet, Barbara T.

    2013-01-01

    Human vision is quantified through the use of standardized clinical vision measurements. These measurements typically include visual acuity (near and far), contrast sensitivity, color vision, stereopsis (a.k.a. stereo acuity), and visual field periphery. Simulator visual system performance is specified in terms such as brightness, contrast, color depth, color gamut, gamma, resolution, and field-of-view. How do these simulator performance characteristics relate to the perceptual experience of the pilot in the simulator? In this paper, visual acuity and contrast sensitivity will be related to simulator visual system resolution, contrast, and dynamic range; similarly, color vision will be related to color depth/color gamut. Finally, we will consider how some characteristics of human vision not typically included in current clinical assessments could be used to better inform simulator requirements (e.g., relating dynamic characteristics of human vision to update rate and other temporal display characteristics).

  15. Texture synthesis models and material perception in the visual periphery

    Science.gov (United States)

    Balas, Benjamin

    2015-03-01

    The feature vocabularies used to support texture synthesis algorithms are increasingly being used to examine various aspects of human visual perception. These algorithms offer both a rich set of features that are typically sufficient to capture the appearance of complex natural inputs and a means of carrying out psychophysical experiments using synthetic textures as a proxy for the transformations ostensibly carried out by the visual system when processing natural images using summary statistics. Texture synthesis algorithms have recently been successfully applied to a wide range of visual tasks including texture perception, visual crowding, visual search, among others. Presently, we used both nonparametric and parametric texture synthesis models to investigate the nature of material perception in the visual periphery. We asked participants to classify images of four natural materials (metal, stone, water, and wood) when briefly presented in the visual periphery and compared the errors made under these viewing conditions to the errors made when judging the material category of synthetic images made from the original targets. We found that the confusions made under these two scenarios were substantially different, suggesting that these particular models do not appear to account for material perception in the periphery.

  16. Teachers' Perceptions of Grading Practices: How Pre-Service Training Makes a Difference

    Science.gov (United States)

    Link, Laura

    2018-01-01

    This study examines the enduring problem of inconsistent K-12 grading practices by exploring the relationship between teachers' perceptions of various grading practices, such as factoring student behavior in academic grades, as related to grade level, district locale, and training. Survey responses from 2,996 K-12 teachers from one suburban and…

  17. Automated visual grading of grain kernels by machine vision

    Science.gov (United States)

    Dubosclard, Pierre; Larnier, Stanislas; Konik, Hubert; Herbulot, Ariane; Devy, Michel

    2015-04-01

    This paper presents two automatic methods for visual grading, designed to solve the industrial problem of evaluation of seed lots from the characterization of a representative sample. The sample is thrown in bulk onto a tray placed in a chamber for acquiring color image in a controlled and reproducible manner. Two image processing methods have been developed to separate, and then characterize each seed present in the image. A shape learning is performed on isolated seeds. Collected information is used for the segmentation. The first approach adopted for the segmentation step is based on simple criteria such as regions, edges and normals to the boundary. Marked point processes are used in the second approach, leading to tackle the problem by a technique of energy minimization. In both approaches, an active contour with shape prior is performed to improve the results. A classification is done on shape or color descriptors to evaluate the quality of the sample.

  18. Automatic visual grading of grain products by machine vision

    Science.gov (United States)

    Dubosclard, Pierre; Larnier, Stanislas; Konik, Hubert; Herbulot, Ariane; Devy, Michel

    2015-11-01

    This paper presents two automatic methods for visual grading, deterministic and probabilistic, designed to solve the industrial problem of evaluation of seed lots from the characterization of a representative sample. The sample is thrown in bulk onto a tray placed in a chamber for acquiring color image in a controlled and reproducible manner. Two image-processing methods have been developed to separate and then characterize each seed present in the image. A shape learning is performed on isolated seeds. Collected information is used for the segmentation. The first approach adopted for the segmentation step is based on simple criteria such as regions, edges, and normals to the boundary. Marked point processes are used in the second approach, leading to tackling of the problem by a technique of energy minimization. In both approaches, an active contour with prior shape is performed to improve the results. A classification is done on shape or color descriptors to evaluate the quality of the sample.

  19. Perception Enhancement using Visual Attributes in Sequence Motif Visualization

    OpenAIRE

    Oon, Yin; Lee, Nung; Kok, Wei

    2016-01-01

    Sequence logo is a well-accepted scientific method to visualize the conservation characteristics of biological sequence motifs. Previous studies found that using sequence logo graphical representation for scientific evidence reports or arguments could seriously cause biases and misinterpretation by users. This study investigates on the visual attributes performance of a sequence logo in helping users to perceive and interpret the information based on preattentive theories and Gestalt principl...

  20. A consumer-grade LCD monitor for precise visual stimulation.

    Science.gov (United States)

    Zhang, Gong-Liang; Li, Ai-Su; Miao, Cheng-Guo; He, Xun; Zhang, Ming; Zhang, Yang

    2018-03-12

    Because they were used for decades to present visual stimuli in psychophysical and psychophysiological studies, cathode ray tubes (CRTs) used to be the gold standard for stimulus presentation in vision research. Recently, as CRTs have become increasingly rare in the market, researchers have started using various types of liquid-crystal display (LCD) monitors as a replacement for CRTs. However, LCDs are typically not cost-effective when used in vision research and often cannot reach the full capacity of a high refresh rate. In this study we measured the temporal and spatial characteristics of a consumer-grade LCD, and the results suggested that a consumer-grade LCD can successfully meet all the technical demands in vision research. The tested LCD, working in a flash style like that of CRTs, demonstrated perfect consistency for initial latencies across locations, yet showed poor spatial uniformity and sluggishness in reaching the requested luminance within the first frame. After these drawbacks were addressed through software corrections, the candidate monitor showed performance comparable or superior to that of CRTs in terms of both spatial and temporal homogeneity. The proposed solution can be used as a replacement for CRTs in vision research.

  1. Visual Perception Based Rate Control Algorithm for HEVC

    Science.gov (United States)

    Feng, Zeqi; Liu, PengYu; Jia, Kebin

    2018-01-01

    For HEVC, rate control is an indispensably important video coding technology to alleviate the contradiction between video quality and the limited encoding resources during video communication. However, the rate control benchmark algorithm of HEVC ignores subjective visual perception. For key focus regions, bit allocation of LCU is not ideal and subjective quality is unsatisfied. In this paper, a visual perception based rate control algorithm for HEVC is proposed. First bit allocation weight of LCU level is optimized based on the visual perception of luminance and motion to ameliorate video subjective quality. Then λ and QP are adjusted in combination with the bit allocation weight to improve rate distortion performance. Experimental results show that the proposed algorithm reduces average 0.5% BD-BR and maximum 1.09% BD-BR at no cost in bitrate accuracy compared with HEVC (HM15.0). The proposed algorithm devotes to improving video subjective quality under various video applications.

  2. Understanding Consumers' In-store Visual Perception

    DEFF Research Database (Denmark)

    Clement, Jesper; Kristensen, Tore; Grønhaug, Kjell

    2013-01-01

    It is widely accepted that the human brain has limited capacity for perceptual stimuli and consumers'' visual attention, when searching for a particular product or brand in a grocery store, should then be limited by the boundaries of their own perceptual capacity. In this exploratory study, we...... examine the relationship between abundant in-store stimuli and limited human perceptual capacity. Specifically, we test the influence of package design features on visual attention. Data was collected through two eye-tracking experiments, one in a grocery store using wireless eye-tracking equipment......, and another in a lab setting. Findings show that consumers have fragmented visual attention during grocery shopping, and that their visual attention is simultaneously influenced and disrupted by the shelf display. Physical design features such as shape and contrast dominate the initial phase of searching...

  3. Influence of Auditory and Haptic Stimulation in Visual Perception

    Directory of Open Access Journals (Sweden)

    Shunichi Kawabata

    2011-10-01

    Full Text Available While many studies have shown that visual information affects perception in the other modalities, little is known about how auditory and haptic information affect visual perception. In this study, we investigated how auditory, haptic, or auditory and haptic stimulation affects visual perception. We used a behavioral task based on the subjects observing the phenomenon of two identical visual objects moving toward each other, overlapping and then continuing their original motion. Subjects may perceive the objects as either streaming each other or bouncing and reversing their direction of motion. With only visual motion stimulus, subjects usually report the objects as streaming, whereas if a sound or flash is played when the objects touch each other, subjects report the objects as bouncing (Bounce-Inducing Effect. In this study, “auditory stimulation”, “haptic stimulation” or “haptic and auditory stimulation” were presented at various times relative to the visual overlap of objects. Our result shows the bouncing rate when haptic and auditory stimulation were presented were the highest. This result suggests that the Bounce-Inducing Effect is enhanced by simultaneous modality presentation to visual motion. In the future, a neuroscience approach (eg, TMS, fMRI may be required to elucidate the brain mechanism in this study.

  4. Visual, Critical, and Scientific Thinking Dispositions in a 3rd Grade Science Classroom

    Science.gov (United States)

    Foss, Stacy

    Many American students leave school without the required 21st century critical thinking skills. This qualitative case study, based on the theoretical concepts of Facione, Arheim, and Vygotsky, explored the development of thinking dispositions through the arts in science on the development of scientific thinking skills when used as a conceptual thinking routine in a rural 3rd grade classroom. Research questions examined the disposition to think critically through the arts in science and focused on the perceptions and experiences of 25 students with the Visual Thinking Strategy (VTS) process. Data were collected from classroom observations (n = 10), student interviews (n = 25), teacher interviews ( n = 1), a focus group discussion (n = 3), and artifacts of student work (n = 25); these data included perceptions of VTS, school culture, and classroom characteristics. An inductive analysis of qualitative data resulted in several emergent themes regarding disposition development and students generating questions while increasing affective motivation. The most prevalent dispositions were open-mindedness, the truth-seeking disposition, the analytical disposition, and the systematicity disposition. The findings about the teachers indicated that VTS questions in science supported "gradual release of responsibility", the internalization of process skills and vocabulary, and argumentation. This case study offers descriptive research that links visual arts inquiry and the development of critical thinking dispositions in science at the elementary level. A science curriculum could be developed, that emphasizes the development of thinking dispositions through the arts in science, which in turn, could impact the professional development of teachers and learning outcomes for students.

  5. Perception of Biological Motion in Central and Peripheral Visual Fields

    Directory of Open Access Journals (Sweden)

    Laicāne Ilze

    2017-10-01

    Full Text Available Studies analysing biological motion perception based on reduced number of dots have demonstrated that biological motion can be perceived even when only the lower part of the body is visible or when the number of dots representing the object is reduced. What is the minimal amount of information that enables biological motion to be distinguished from its scrambled version? The results of the current experiment demonstrate that biological motion can be distinguished from its scrambled version when the object is formed of approximately 5 (4.7 ± 0.1 dots. Additionally, we also investigated whether the threshold value for biological motion perception differs in central and peripheral visual fields. By using stimulus magnification, we demonstrate that the number of dots sufficient for biological motion perception is similar in the central visual field and near periphery. Hence, stimulus magnification can compensate for reduced task performance in the peripheral visual field. The current results suggest that reduced performance of biological motion perception in the peripheral visual field (as demonstrated in other studies is due to difficulties with the global perception of biological motion.

  6. Ambiguities and conventions in the perception of visual art.

    Science.gov (United States)

    Mamassian, Pascal

    2008-09-01

    Vision perception is ambiguous and visual arts play with these ambiguities. While perceptual ambiguities are resolved with prior constraints, artistic ambiguities are resolved by conventions. Is there a relationship between priors and conventions? This review surveys recent work related to these ambiguities in composition, spatial scale, illumination and color, three-dimensional layout, shape, and movement. While most conventions seem to have their roots in perceptual constraints, those conventions that differ from priors may help us appreciate how visual arts differ from everyday perception.

  7. Does visual attention drive the dynamics of bistable perception?

    Science.gov (United States)

    Dieter, Kevin C; Brascamp, Jan; Tadin, Duje; Blake, Randolph

    2016-10-01

    How does attention interact with incoming sensory information to determine what we perceive? One domain in which this question has received serious consideration is that of bistable perception: a captivating class of phenomena that involves fluctuating visual experience in the face of physically unchanging sensory input. Here, some investigations have yielded support for the idea that attention alone determines what is seen, while others have implicated entirely attention-independent processes in driving alternations during bistable perception. We review the body of literature addressing this divide and conclude that in fact both sides are correct-depending on the form of bistable perception being considered. Converging evidence suggests that visual attention is required for alternations in the type of bistable perception called binocular rivalry, while alternations during other types of bistable perception appear to continue without requiring attention. We discuss some implications of this differential effect of attention for our understanding of the mechanisms underlying bistable perception, and examine how these mechanisms operate during our everyday visual experiences.

  8. Visual influences on speech perception in children with autism.

    Science.gov (United States)

    Iarocci, Grace; Rombough, Adrienne; Yager, Jodi; Weeks, Daniel J; Chua, Romeo

    2010-07-01

    The bimodal perception of speech sounds was examined in children with autism as compared to mental age-matched typically developing (TD) children. A computer task was employed wherein only the mouth region of the face was displayed and children reported what they heard or saw when presented with consonant-vowel sounds in unimodal auditory condition, unimodal visual condition, and a bimodal condition. Children with autism showed less visual influence and more auditory influence on their bimodal speech perception as compared to their TD peers, largely due to significantly worse performance in the unimodal visual condition (lip reading). Children with autism may not benefit to the same extent as TD children from visual cues such as lip reading that typically support the processing of speech sounds. The disadvantage in lip reading may be detrimental when auditory input is degraded, for example in school settings, whereby speakers are communicating in frequently noisy environments.

  9. Relationship between Vision and Visual Perception in Hong Kong Preschoolers.

    Science.gov (United States)

    Ho, Wing-Cheung; Tang, Minny Mei-Miu; Fu, Ching-Wah; Leung, Ka-Yan; Pang, Peter Chi-Kong; Cheong, Allen Ming-Yan

    2015-05-01

    Although superior performance in visual motor and visual perceptual skills of preschool children has been documented in the Chinese population, a normative database is only available for the US population. This study aimed to determine the normative values for these visuomotor and visual perceptual tests for preschool children in the Hong Kong Chinese population and to investigate the effect of fundamental visual functions on visuomotor and visual perceptual skills. One hundred seventy-four children from six different kindergartens in Hong Kong were recruited. Distance visual acuity, near visual acuity, and stereopsis were tested, along with two measures of visual perception (VP): Visual-Motor Integration (VMI) and Test of Visual-Perceptual Skills (TVPS). Raw VMI and TVPS scores were converted into standard/scaled scores. The impact of basic visual functions on VP (VMI and TVPS) was examined using multiple regression. Visual functions were generally good: only 9.2 and 4.6% of subjects had unilateral and bilateral reduced habitual vision, respectively (distance visual acuity in the better eye >0.3 logMAR [logarithm of the minimum angle of resolution]). Performance in the VMI and in the visual memory and spatial relationships subtests of the TVPS exceeded that reported for age-matched children from the United States. Multiple regression analysis provided evidence that age had the strongest predictive value for the VMI and VP skills. In addition, near visual acuity was weakly associated with performance in the VMI and the visual discrimination and spatial relationships subtests of the TVPS, accounting for a limited proportion of the intersubject variability (R memory/spatial relationships of TVPS subtests, perhaps attributed to greater exposure to such material during their preschool home education. This study provided normality data for VMI and four subtests of the TVPS for Hong Kong Chinese preschool children as a reference for future studies.

  10. Odors bias time perception in visual and auditory modalities

    Directory of Open Access Journals (Sweden)

    Zhenzhu eYue

    2016-04-01

    Full Text Available Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 ms or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor. The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a

  11. Odors Bias Time Perception in Visual and Auditory Modalities.

    Science.gov (United States)

    Yue, Zhenzhu; Gao, Tianyu; Chen, Lihan; Wu, Jiashuang

    2016-01-01

    Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal) were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor). The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a framework of

  12. Perceptual Training Strongly Improves Visual Motion Perception in Schizophrenia

    Science.gov (United States)

    Norton, Daniel J.; McBain, Ryan K.; Ongur, Dost; Chen, Yue

    2011-01-01

    Schizophrenia patients exhibit perceptual and cognitive deficits, including in visual motion processing. Given that cognitive systems depend upon perceptual inputs, improving patients' perceptual abilities may be an effective means of cognitive intervention. In healthy people, motion perception can be enhanced through perceptual learning, but it…

  13. Visual space perception at different levels of depth description

    Czech Academy of Sciences Publication Activity Database

    Šikl, Radovan; Šimeček, Michal

    2015-01-01

    Roč. 77, č. 6 (2015), 2098–2107 ISSN 1943-3921 R&D Projects: GA ČR GA13-28709S Institutional support: RVO:68081740 Keywords : visual space perception * Depth scales * Level of description Subject RIV: AN - Psychology Impact factor: 1.782, year: 2015

  14. Audio-Visual Speech Perception: A Developmental ERP Investigation

    Science.gov (United States)

    Knowland, Victoria C. P.; Mercure, Evelyne; Karmiloff-Smith, Annette; Dick, Fred; Thomas, Michael S. C.

    2014-01-01

    Being able to see a talking face confers a considerable advantage for speech perception in adulthood. However, behavioural data currently suggest that children fail to make full use of these available visual speech cues until age 8 or 9. This is particularly surprising given the potential utility of multiple informational cues during language…

  15. Vividness of Visual Imagery Depends on the Neural Overlap with Perception in Visual Areas.

    Science.gov (United States)

    Dijkstra, Nadine; Bosch, Sander E; van Gerven, Marcel A J

    2017-02-01

    Research into the neural correlates of individual differences in imagery vividness point to an important role of the early visual cortex. However, there is also great fluctuation of vividness within individuals, such that only looking at differences between people necessarily obscures the picture. In this study, we show that variation in moment-to-moment experienced vividness of visual imagery, within human subjects, depends on the activity of a large network of brain areas, including frontal, parietal, and visual areas. Furthermore, using a novel multivariate analysis technique, we show that the neural overlap between imagery and perception in the entire visual system correlates with experienced imagery vividness. This shows that the neural basis of imagery vividness is much more complicated than studies of individual differences seemed to suggest. Visual imagery is the ability to visualize objects that are not in our direct line of sight: something that is important for memory, spatial reasoning, and many other tasks. It is known that the better people are at visual imagery, the better they can perform these tasks. However, the neural correlates of moment-to-moment variation in visual imagery remain unclear. In this study, we show that the more the neural response during imagery is similar to the neural response during perception, the more vivid or perception-like the imagery experience is. Copyright © 2017 the authors 0270-6474/17/371367-07$15.00/0.

  16. Hemispheric asymmetry in the influence of language on visual perception.

    Science.gov (United States)

    Sun, Yanliang; Cai, Yongchun; Lu, Shena

    2015-07-01

    Many studies have shown that language can affect visual perception; however, our understanding of the neural basis of linguistic influence is inadequate. This can be investigated by examining the hemispheric asymmetry of linguistic influence. The left and right hemispheres are dominant in close and distant semantic processing, respectively. In this study, we investigated whether the hemispheric asymmetry of semantic processing led to hemispheric asymmetry for concept priming on the detection of objects degraded by continuous flash suppression. We combined a priming paradigm with the divided visual field paradigm and used continuous flash suppression, which renders objects invisible. The results indicated that the hemispheric asymmetry of semantic processing led to a right lateralization in the influence of more abstract concepts on visual perception. The lateralization of brain connectomes may be the underlying neural basis of this effect. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Neuronal codes for visual perception and memory.

    Science.gov (United States)

    Quian Quiroga, Rodrigo

    2016-03-01

    In this review, I describe and contrast the representation of stimuli in visual cortical areas and in the medial temporal lobe (MTL). While cortex is characterized by a distributed and implicit coding that is optimal for recognition and storage of semantic information, the MTL shows a much sparser and explicit coding of specific concepts that is ideal for episodic memory. I will describe the main characteristics of the coding in the MTL by the so-called concept cells and will then propose a model of the formation and recall of episodic memory based on partially overlapping assemblies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Do gender differences in audio-visual benefit and visual influence in audio-visual speech perception emerge with age?

    Directory of Open Access Journals (Sweden)

    Magnus eAlm

    2015-07-01

    Full Text Available Gender and age have been found to affect adults’ audio-visual (AV speech perception. However, research on adult aging focuses on adults over 60 years, who have an increasing likelihood for cognitive and sensory decline, which may confound positive effects of age-related AV-experience and its interaction with gender. Observed age and gender differences in AV speech perception may also depend on measurement sensitivity and AV task difficulty. Consequently both AV benefit and visual influence were used to measure visual contribution for gender-balanced groups of young (20-30 years and middle-aged adults (50-60 years with task difficulty varied using AV syllables from different talkers in alternative auditory backgrounds. Females had better speech-reading performance than males. Whereas no gender differences in AV benefit or visual influence were observed for young adults, visually influenced responses were significantly greater for middle-aged females than middle-aged males. That speech-reading performance did not influence AV benefit may be explained by visual speech extraction and AV integration constituting independent abilities. Contrastingly, the gender difference in visually influenced responses in middle adulthood may reflect an experience-related shift in females’ general AV perceptual strategy. Although young females’ speech-reading proficiency may not readily contribute to greater visual influence, between young and middle-adulthood recurrent confirmation of the contribution of visual cues induced by speech-reading proficiency may gradually shift females AV perceptual strategy towards more visually dominated responses.

  19. Visual-vestibular integration motion perception reporting

    Science.gov (United States)

    Harm, Deborah L.; Reschke, Millard R.; Parker, Donald E.

    1999-01-01

    Self-orientation and self/surround-motion perception derive from a multimodal sensory process that integrates information from the eyes, vestibular apparatus, proprioceptive and somatosensory receptors. Results from short and long duration spaceflight investigations indicate that: (1) perceptual and sensorimotor function was disrupted during the initial exposure to microgravity and gradually improved over hours to days (individuals adapt), (2) the presence and/or absence of information from different sensory modalities differentially affected the perception of orientation, self-motion and surround-motion, (3) perceptual and sensorimotor function was initially disrupted upon return to Earth-normal gravity and gradually recovered to preflight levels (individuals readapt), and (4) the longer the exposure to microgravity, the more complete the adaptation, the more profound the postflight disturbances, and the longer the recovery period to preflight levels. While much has been learned about perceptual and sensorimotor reactions and adaptation to microgravity, there is much remaining to be learned about the mechanisms underlying the adaptive changes, and about how intersensory interactions affect perceptual and sensorimotor function during voluntary movements. During space flight, SMS and perceptual disturbances have led to reductions in performance efficiency and sense of well-being. During entry and immediately after landing, such disturbances could have a serious impact on the ability of the commander to land the Orbiter and on the ability of all crew members to egress from the Orbiter, particularly in a non-nominal condition or following extended stays in microgravity. An understanding of spatial orientation and motion perception is essential for developing countermeasures for Space Motion Sickness (SMS) and perceptual disturbances during spaceflight and upon return to Earth. Countermeasures for optimal performance in flight and a successful return to Earth require

  20. Contrast and strength of visual memory and imagery differentially affect visual perception.

    Science.gov (United States)

    Saad, Elyana; Silvanto, Juha

    2013-01-01

    Visual short-term memory (VSTM) and visual imagery have been shown to modulate visual perception. However, how the subjective experience of VSTM/imagery and its contrast modulate this process has not been investigated. We addressed this issue by asking participants to detect brief masked targets while they were engaged either in VSTM or visual imagery. Subjective experience of memory/imagery (strength scale), and the visual contrast of the memory/mental image (contrast scale) were assessed on a trial-by-trial basis. For both VSTM and imagery, contrast of the memory/mental image was positively associated with reporting target presence. Consequently, at the sensory level, both VSTM and imagery facilitated visual perception. However, subjective strength of VSTM was positively associated with visual detection whereas the opposite pattern was found for imagery. Thus the relationship between subjective strength of memory/imagery and visual detection are qualitatively different for VSTM and visual imagery, although their impact at the sensory level appears similar. Our results furthermore demonstrate that imagery and VSTM are partly dissociable processes.

  1. Statistical regularities in art: Relations with visual coding and perception.

    Science.gov (United States)

    Graham, Daniel J; Redies, Christoph

    2010-07-21

    Since at least 1935, vision researchers have used art stimuli to test human response to complex scenes. This is sensible given the "inherent interestingness" of art and its relation to the natural visual world. The use of art stimuli has remained popular, especially in eye tracking studies. Moreover, stimuli in common use by vision scientists are inspired by the work of famous artists (e.g., Mondrians). Artworks are also popular in vision science as illustrations of a host of visual phenomena, such as depth cues and surface properties. However, until recently, there has been scant consideration of the spatial, luminance, and color statistics of artwork, and even less study of ways that regularities in such statistics could affect visual processing. Furthermore, the relationship between regularities in art images and those in natural scenes has received little or no attention. In the past few years, there has been a concerted effort to study statistical regularities in art as they relate to neural coding and visual perception, and art stimuli have begun to be studied in rigorous ways, as natural scenes have been. In this minireview, we summarize quantitative studies of links between regular statistics in artwork and processing in the visual stream. The results of these studies suggest that art is especially germane to understanding human visual coding and perception, and it therefore warrants wider study. Copyright 2010 Elsevier Ltd. All rights reserved.

  2. Play in Grade R classrooms: Diverse teacher perceptions and practices

    Directory of Open Access Journals (Sweden)

    Shelley Aronstam

    2016-02-01

    Full Text Available The study explores the role of play in Grade R classrooms in the Cape Peninsula. The focus is on perceptions of teachers from differing backgrounds regarding how play is supported and utilised in the classroom. Theories of childhood play as propounded by Jean Piaget and Lev Vygotsky provide the theoretical background to our understanding of child play. Data were collected from 104 teachers in 41 primary schools and early childhood development (ECD centres in both well-resourced and under-resourced environments, using semi-structured interviews and guided observations of practice. It was found that, although play is a difficult concept to define, it is easy to recognise. Teachers at some schools seem to have less knowledge of the pedagogy of play. Insights into early childhood teachers’ views on the role of play in the curriculum have the potential to inform the planning for teacher training and national policy development for early years’ learning. For these reasons, it is necessary to define and understand structured and formal play in the diverse contexts of South Africa, specifically by following, through the years, the teachers who utilise play as pedagogical tool.

  3. Visual Timing of Structured Dance Movements Resembles Auditory Rhythm Perception.

    Science.gov (United States)

    Su, Yi-Huang; Salazar-López, Elvira

    2016-01-01

    Temporal mechanisms for processing auditory musical rhythms are well established, in which a perceived beat is beneficial for timing purposes. It is yet unknown whether such beat-based timing would also underlie visual perception of temporally structured, ecological stimuli connected to music: dance. In this study, we investigated whether observers extracted a visual beat when watching dance movements to assist visual timing of these movements. Participants watched silent videos of dance sequences and reproduced the movement duration by mental recall. We found better visual timing for limb movements with regular patterns in the trajectories than without, similar to the beat advantage for auditory rhythms. When movements involved both the arms and the legs, the benefit of a visual beat relied only on the latter. The beat-based advantage persisted despite auditory interferences that were temporally incongruent with the visual beat, arguing for the visual nature of these mechanisms. Our results suggest that visual timing principles for dance parallel their auditory counterparts for music, which may be based on common sensorimotor coupling. These processes likely yield multimodal rhythm representations in the scenario of music and dance.

  4. Processing reafferent and exafferent visual information for action and perception.

    Science.gov (United States)

    Reichenbach, Alexandra; Diedrichsen, Jörn

    2015-01-01

    A recent study suggests that reafferent hand-related visual information utilizes a privileged, attention-independent processing channel for motor control. This process was termed visuomotor binding to reflect its proposed function: linking visual reafferences to the corresponding motor control centers. Here, we ask whether the advantage of processing reafferent over exafferent visual information is a specific feature of the motor processing stream or whether the improved processing also benefits the perceptual processing stream. Human participants performed a bimanual reaching task in a cluttered visual display, and one of the visual hand cursors could be displaced laterally during the movement. We measured the rapid feedback responses of the motor system as well as matched perceptual judgments of which cursor was displaced. Perceptual judgments were either made by watching the visual scene without moving or made simultaneously to the reaching tasks, such that the perceptual processing stream could also profit from the specialized processing of reafferent information in the latter case. Our results demonstrate that perceptual judgments in the heavily cluttered visual environment were improved when performed based on reafferent information. Even in this case, however, the filtering capability of the perceptual processing stream suffered more from the increasing complexity of the visual scene than the motor processing stream. These findings suggest partly shared and partly segregated processing of reafferent information for vision for motor control versus vision for perception.

  5. Visual Timing of Structured Dance Movements Resembles Auditory Rhythm Perception

    Directory of Open Access Journals (Sweden)

    Yi-Huang Su

    2016-01-01

    Full Text Available Temporal mechanisms for processing auditory musical rhythms are well established, in which a perceived beat is beneficial for timing purposes. It is yet unknown whether such beat-based timing would also underlie visual perception of temporally structured, ecological stimuli connected to music: dance. In this study, we investigated whether observers extracted a visual beat when watching dance movements to assist visual timing of these movements. Participants watched silent videos of dance sequences and reproduced the movement duration by mental recall. We found better visual timing for limb movements with regular patterns in the trajectories than without, similar to the beat advantage for auditory rhythms. When movements involved both the arms and the legs, the benefit of a visual beat relied only on the latter. The beat-based advantage persisted despite auditory interferences that were temporally incongruent with the visual beat, arguing for the visual nature of these mechanisms. Our results suggest that visual timing principles for dance parallel their auditory counterparts for music, which may be based on common sensorimotor coupling. These processes likely yield multimodal rhythm representations in the scenario of music and dance.

  6. Visual Timing of Structured Dance Movements Resembles Auditory Rhythm Perception

    Science.gov (United States)

    Su, Yi-Huang; Salazar-López, Elvira

    2016-01-01

    Temporal mechanisms for processing auditory musical rhythms are well established, in which a perceived beat is beneficial for timing purposes. It is yet unknown whether such beat-based timing would also underlie visual perception of temporally structured, ecological stimuli connected to music: dance. In this study, we investigated whether observers extracted a visual beat when watching dance movements to assist visual timing of these movements. Participants watched silent videos of dance sequences and reproduced the movement duration by mental recall. We found better visual timing for limb movements with regular patterns in the trajectories than without, similar to the beat advantage for auditory rhythms. When movements involved both the arms and the legs, the benefit of a visual beat relied only on the latter. The beat-based advantage persisted despite auditory interferences that were temporally incongruent with the visual beat, arguing for the visual nature of these mechanisms. Our results suggest that visual timing principles for dance parallel their auditory counterparts for music, which may be based on common sensorimotor coupling. These processes likely yield multimodal rhythm representations in the scenario of music and dance. PMID:27313900

  7. Dental anatomy grading: comparison between conventional visual and a novel digital assessment technique.

    Science.gov (United States)

    Kwon, So Ran; Restrepo-Kennedy, Natalia; Dawson, Deborah V; Hernandez, Marcela; Denehy, Gerald; Blanchette, Derek; Gratton, David G; Aquilino, Steven A; Armstrong, Steven R

    2014-12-01

    Conventional grading of dental students' projects in preclinical courses has mainly relied on visual evaluation by experienced instructors. The purpose of this study was to compare conventional visual grading in a dental anatomy course at one U.S. dental school to a novel digital assessment technique. A total of sixty samples comprised of two sets of faculty wax-ups (n=30), student wax-ups (n=15), and dentoform teeth of tooth #14 (n=15) were used for this study. Two additional faculty members visually graded the samples according to a checklist and then repeated the grading after one week. The sample wax-up with the highest score based on the visual grading was selected as the master model for the digital grading, which was also performed twice with an interim period of one week. Descriptive statistics and signed rank tests for systematic bias were used for intra- and interrater comparisons. The intraclass correlation (ICC) was used as a measure of intra- and interrater reliability. None of the faculty members achieved the minimum acceptable intrarater agreement of 0.8. Interrater agreement was substantially less than intrarater agreement for the visual grading, whereas all measures of intrarater agreement were greater than 0.9 and considered excellent for the digital assessment technique. These results suggest that visual grading is limited by modest intrarater reliability and low interrater agreement. Digital grading is a promising evaluation method showing excellent intrarater reliability and correlation. Correlation for visual and digital grading was consistently modest, partly supporting the potential use of digital technology in dental anatomy grading.

  8. Interoceptive signals impact visual processing: Cardiac modulation of visual body perception.

    Science.gov (United States)

    Ronchi, Roberta; Bernasconi, Fosco; Pfeiffer, Christian; Bello-Ruiz, Javier; Kaliuzhna, Mariia; Blanke, Olaf

    2017-09-01

    Multisensory perception research has largely focused on exteroceptive signals, but recent evidence has revealed the integration of interoceptive signals with exteroceptive information. Such research revealed that heartbeat signals affect sensory (e.g., visual) processing: however, it is unknown how they impact the perception of body images. Here we linked our participants' heartbeat to visual stimuli and investigated the spatio-temporal brain dynamics of cardio-visual stimulation on the processing of human body images. We recorded visual evoked potentials with 64-channel electroencephalography while showing a body or a scrambled-body (control) that appeared at the frequency of the on-line recorded participants' heartbeat or not (not-synchronous, control). Extending earlier studies, we found a body-independent effect, with cardiac signals enhancing visual processing during two time periods (77-130 ms and 145-246 ms). Within the second (later) time-window we detected a second effect characterised by enhanced activity in parietal, temporo-occipital, inferior frontal, and right basal ganglia-insula regions, but only when non-scrambled body images were flashed synchronously with the heartbeat (208-224 ms). In conclusion, our results highlight the role of interoceptive information for the visual processing of human body pictures within a network integrating cardio-visual signals of relevance for perceptual and cognitive aspects of visual body processing. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Audio-visual temporal perception in children with restored hearing.

    Science.gov (United States)

    Gori, Monica; Chilosi, Anna; Forli, Francesca; Burr, David

    2017-05-01

    It is not clear how audio-visual temporal perception develops in children with restored hearing. In this study we measured temporal discrimination thresholds with an audio-visual temporal bisection task in 9 deaf children with restored audition, and 22 typically hearing children. In typically hearing children, audition was more precise than vision, with no gain in multisensory conditions (as previously reported in Gori et al. (2012b)). However, deaf children with restored audition showed similar thresholds for audio and visual thresholds and some evidence of gain in audio-visual temporal multisensory conditions. Interestingly, we found a strong correlation between auditory weighting of multisensory signals and quality of language: patients who gave more weight to audition had better language skills. Similarly, auditory thresholds for the temporal bisection task were also a good predictor of language skills. This result supports the idea that the temporal auditory processing is associated with language development. Copyright © 2017. Published by Elsevier Ltd.

  10. Audio-visual speech perception: a developmental ERP investigation

    Science.gov (United States)

    Knowland, Victoria CP; Mercure, Evelyne; Karmiloff-Smith, Annette; Dick, Fred; Thomas, Michael SC

    2014-01-01

    Being able to see a talking face confers a considerable advantage for speech perception in adulthood. However, behavioural data currently suggest that children fail to make full use of these available visual speech cues until age 8 or 9. This is particularly surprising given the potential utility of multiple informational cues during language learning. We therefore explored this at the neural level. The event-related potential (ERP) technique has been used to assess the mechanisms of audio-visual speech perception in adults, with visual cues reliably modulating auditory ERP responses to speech. Previous work has shown congruence-dependent shortening of auditory N1/P2 latency and congruence-independent attenuation of amplitude in the presence of auditory and visual speech signals, compared to auditory alone. The aim of this study was to chart the development of these well-established modulatory effects over mid-to-late childhood. Experiment 1 employed an adult sample to validate a child-friendly stimulus set and paradigm by replicating previously observed effects of N1/P2 amplitude and latency modulation by visual speech cues; it also revealed greater attenuation of component amplitude given incongruent audio-visual stimuli, pointing to a new interpretation of the amplitude modulation effect. Experiment 2 used the same paradigm to map cross-sectional developmental change in these ERP responses between 6 and 11 years of age. The effect of amplitude modulation by visual cues emerged over development, while the effect of latency modulation was stable over the child sample. These data suggest that auditory ERP modulation by visual speech represents separable underlying cognitive processes, some of which show earlier maturation than others over the course of development. PMID:24176002

  11. Visual MRI grading system to evaluate atrophy of the supeaspinatus muscle

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hyun Kyoung; Hong, Sung Hwan; Yoo, Hye Jin; Choi, Ja Young; Kim, Sae Hoon; Choi, Jung Ah; Kang, Heung Sik [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2014-08-15

    To investigate the interobserver reproducibility and diagnostic feasibility of a visual grading system for assessing atrophy of the supraspinatus muscle on magnetic resonance imaging (MRI). Three independent radiologists retrospectively evaluated the occupying ratio of the supraspinatus muscle in the supraspinatus fossa on 192 shoulder MRI examinations in 188 patients using a 3-point visual grading system (1, ≥ 60%; 2, 30-59%; 3, < 30%) on oblique sagittal T1-weighted images. The inter-reader agreement and the agreement with the reference standard (3-point grades according to absolute occupying ratio values quantitatively measured by directly contouring the muscles on MRI) were analyzed using weighted kappa. The visual grading was applied by a single reader to a group of 100 consecutive patients who had undergone rotator cuff repair to retrospectively determine the association between the visual grades at preoperative state and postsurgical occurrences of retear. The inter-reader weighted kappa value for the visual grading was 0.74 when averaged across three reader pairs (0.70-0.77 for individual reader pairs). The weighted kappa value between the visual grading and the reference standard ranged from 0.75 to 0.83. There was a significant difference in retear rates of the rotator cuff between the 3 visual grades of supraspinatus muscle atrophy on MRI in univariable analysis (p < 0.001), but not in multivariable analysis (p = 0.026). The 3-point visual grading system may be a feasible method to assess the severity of supraspinatus muscle atrophy on MRI and assist in the clinical management of patients with rotator cuff tear.

  12. Visual MRI grading system to evaluate atrophy of the supeaspinatus muscle

    International Nuclear Information System (INIS)

    Lim, Hyun Kyoung; Hong, Sung Hwan; Yoo, Hye Jin; Choi, Ja Young; Kim, Sae Hoon; Choi, Jung Ah; Kang, Heung Sik

    2014-01-01

    To investigate the interobserver reproducibility and diagnostic feasibility of a visual grading system for assessing atrophy of the supraspinatus muscle on magnetic resonance imaging (MRI). Three independent radiologists retrospectively evaluated the occupying ratio of the supraspinatus muscle in the supraspinatus fossa on 192 shoulder MRI examinations in 188 patients using a 3-point visual grading system (1, ≥ 60%; 2, 30-59%; 3, < 30%) on oblique sagittal T1-weighted images. The inter-reader agreement and the agreement with the reference standard (3-point grades according to absolute occupying ratio values quantitatively measured by directly contouring the muscles on MRI) were analyzed using weighted kappa. The visual grading was applied by a single reader to a group of 100 consecutive patients who had undergone rotator cuff repair to retrospectively determine the association between the visual grades at preoperative state and postsurgical occurrences of retear. The inter-reader weighted kappa value for the visual grading was 0.74 when averaged across three reader pairs (0.70-0.77 for individual reader pairs). The weighted kappa value between the visual grading and the reference standard ranged from 0.75 to 0.83. There was a significant difference in retear rates of the rotator cuff between the 3 visual grades of supraspinatus muscle atrophy on MRI in univariable analysis (p < 0.001), but not in multivariable analysis (p = 0.026). The 3-point visual grading system may be a feasible method to assess the severity of supraspinatus muscle atrophy on MRI and assist in the clinical management of patients with rotator cuff tear.

  13. Dokuzuncu Sınıf Tarih Ders Kitabında Yer Alan Görseller Hakkında Öğretmen Görüşleri: Trabzon Örneği Perceptions of History Teachers about Visual Materials of Ninth Grade History Textbook

    Directory of Open Access Journals (Sweden)

    Ebru DEMİRCİOĞLU

    2013-09-01

    Full Text Available Textbooks are important tools of teaching and learning process ineducation system. There are some important criteria in preparingtextbooks. Especially visual materials which should be paid attention inthe preparation process of textbooks are important. Visual materials ofa qualified textbook should also have the following criteria which are asfollows: harmony between text and visual materials, clarity andcatching attention of students.The purpose of this thesis is to determine perceptions of historyteachers about visual materials of ninth grade history textbooks. Theresearch carried out experienced history teachers who teach history inthe city center of Trabzon and on the coast of the province of Trabzon.The purposive sampling was used in the research to choose historyteachers. A qualitative approach was used in the study and two datacollection tools which are an open-ended questionnaire and a semistructuredinterview to gather data. 49 history teachers participatedopen-ended questionnaire and semi-structured interviews carried outwith 8 teachers. In the light of the data, it seems that the great majorityof history teachers do not know how to use visual materials in historytextbooks and think that visual materials in the ninth grade historytextbooks do not explain texts properly. Furthermore, they also statedthat some visual materials in the ninth grade history textbook are notclear and understandable. Ders kitapları eğitim ve öğretim sürecinin en önemli unsurları arsında yer almaktadır. Bu materyallerin hazırlanmasında pek çok husus dikkate alınmalıdır. Ders kitabı hazırlama sürecinde dikkat edilmesi gereken hususların başında görseller gelmektedir. Nitelikli bir ders kitabında görseller metinle uyumlu olmanın yanında, açık, anlaşılır ve öğrencilerin ilgisini çekecek şekilde yapılandırılmalıdır.Bu çalışmanın amacı, Trabzon ilinde bulunan tarih öğretmenlerinin, dokuzuncu sınıf Tarih ders kitab

  14. Perception of Visual Variables on Tiled Wall-Sized Displays for Information Visualization Applications.

    Science.gov (United States)

    Bezerianos, A; Isenberg, P

    2012-12-01

    We present the results of two user studies on the perception of visual variables on tiled high-resolution wall-sized displays. We contribute an understanding of, and indicators predicting how, large variations in viewing distances and viewing angles affect the accurate perception of angles, areas, and lengths. Our work, thus, helps visualization researchers with design considerations on how to create effective visualizations for these spaces. The first study showed that perception accuracy was impacted most when viewers were close to the wall but differently for each variable (Angle, Area, Length). Our second study examined the effect of perception when participants could move freely compared to when they had a static viewpoint. We found that a far but static viewpoint was as accurate but less time consuming than one that included free motion. Based on our findings, we recommend encouraging viewers to stand further back from the display when conducting perception estimation tasks. If tasks need to be conducted close to the wall display, important information should be placed directly in front of the viewer or above, and viewers should be provided with an estimation of the distortion effects predicted by our work-or encouraged to physically navigate the wall in specific ways to reduce judgement error.

  15. The interplay of language and visual perception in working memory.

    Science.gov (United States)

    Souza, Alessandra S; Skóra, Zuzanna

    2017-09-01

    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. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. The Perception of the Higher Derivatives of Visual Motion.

    Science.gov (United States)

    1986-06-24

    Familiar size and the perception of Filion. R. D. L. On the visual detection ofaccelerated motion. Unpublished depth. Journal of Psychology, 1952,34, 107...S. The retinal size of a Kaufman, L. Sight and mind. New York: Oxford University Press, familiar object as a determiner of apparent distance...stereoknetici. Archivo Italiano di Psicologia . tection: Comparison of postadaptation thresholds. Journal of the 1924.3. 105-120. Optical Society of America. 1983

  17. First steps into understanding teachers' visual perception of classroom events

    OpenAIRE

    Van den Bogert, Niek; Van Brugggen, Jan; Kostons, Danny; Jochems, Wim

    2018-01-01

    Student-teachers struggle to become competent at classroom management. To do so, Berliner (2001) and Feldon (2007) argue for the significance of speedy and accurate recognition of relevant cues for teacher action in the classroom. However, studies investigating how teachers obtain this information from the classroom are scarce. This study employed eye-tracking methodology to investigate teachers' visual perception and detection of classroom events. Results show that experienced teachers proce...

  18. From Cortical Blindness to Conscious Visual Perception: Theories on Neuronal Networks and Visual Training Strategies.

    Science.gov (United States)

    Hadid, Vanessa; Lepore, Franco

    2017-01-01

    Homonymous hemianopia (HH) is the most common cortical visual impairment leading to blindness in the contralateral hemifield. It is associated with many inconveniences and daily restrictions such as exploration and visual orientation difficulties. However, patients with HH can preserve the remarkable ability to unconsciously perceive visual stimuli presented in their blindfield, a phenomenon known as blindsight. Unfortunately, the nature of this captivating residual ability is still misunderstood and the rehabilitation strategies in terms of visual training have been insufficiently exploited. This article discusses type I and type II blindsight in a neuronal framework of altered global workspace, resulting from inefficient perception, attention and conscious networks. To enhance synchronization and create global availability for residual abilities to reach visual consciousness, rehabilitation tools need to stimulate subcortical extrastriate pathways through V5/MT. Multisensory bottom-up compensation combined with top-down restitution training could target pre-existing and new neuronal mechanisms to recreate a framework for potential functionality.

  19. Aesthetic Perception of Visual Textures: A Holistic Exploration using Texture Analysis, Psychological Experiment and Perception Modeling

    Directory of Open Access Journals (Sweden)

    Jianli eLiu

    2015-11-01

    Full Text Available Modeling human aesthetic perception of visual textures is important and valuable in numerous industrial domains, such as product design, architectural design and decoration. Based on results from a semantic differential rating experiment, we modeled the relationship between low-level basic texture features and aesthetic properties involved in human aesthetic texture perception. First, we compute basic texture features from textural images using four classical methods. These features are neutral, objective and independent of the socio-cultural context of the visual textures. Then, we conduct a semantic differential rating experiment to collect from evaluators their aesthetic perceptions of selected textural stimuli. In semantic differential rating experiment, eights pairs of aesthetic properties are chosen, which are strongly related to the socio-cultural context of the selected textures and to human emotions. They are easily understood and connected to everyday life. We propose a hierarchical feed-forward layer model of aesthetic texture perception and assign 8 pairs of aesthetic properties to different layers. Finally, we describe the generation of multiple linear and nonlinear regression models for aesthetic prediction by taking dimensionality-reduced texture features and aesthetic properties of visual textures as dependent and independent variables, respectively. Our experimental results indicate that the relationships between each layer and its neighbors in the hierarchical feed-forward layer model of aesthetic texture perception can be fitted well by linear functions, and the models thus generated can successfully bridge the gap between computational texture features and aesthetic texture properties.

  20. Knowledge corruption for visual perception in individuals high on paranoia.

    Science.gov (United States)

    Moritz, Steffen; Göritz, Anja S; Van Quaquebeke, Niels; Andreou, Christina; Jungclaussen, David; Peters, Maarten J V

    2014-03-30

    Studies revealed that patients with paranoid schizophrenia display overconfidence in errors for memory and social cognition tasks. The present investigation examined whether this pattern holds true for visual perception tasks. Nonclinical participants were recruited via an online panel. Individuals were asked to complete a questionnaire that included the Paranoia Checklist and were then presented with 24 blurry pictures; half contained a hidden object while the other half showed snowy (visual) noise. Participants were asked to state whether the visual items contained an object and how confident they were in their judgment. Data from 1966 individuals were included following a conservative selection process. Participants high on core paranoid symptoms showed a poor calibration of confidence for correct versus incorrect responses. In particular, participants high on paranoia displayed overconfidence in incorrect responses and demonstrated a 20% error rate for responses made with high confidence compared to a 12% error rate in participants with low paranoia scores. Interestingly, paranoia scores declined after performance of the task. For the first time, overconfidence in errors was demonstrated among individuals with high levels of paranoia using a visual perception task, tentatively suggesting it is a ubiquitous phenomenon. In view of the significant decline in paranoia across time, bias modification programs may incorporate items such as the one employed here to teach patients with clinical paranoia the fallibility of human cognition, which may foster subsequent symptom improvement. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Visual perception system and method for a humanoid robot

    Science.gov (United States)

    Wells, James W. (Inventor); Mc Kay, Neil David (Inventor); Chelian, Suhas E. (Inventor); Linn, Douglas Martin (Inventor); Wampler, II, Charles W. (Inventor); Bridgwater, Lyndon (Inventor)

    2012-01-01

    A robotic system includes a humanoid robot with robotic joints each moveable using an actuator(s), and a distributed controller for controlling the movement of each of the robotic joints. The controller includes a visual perception module (VPM) for visually identifying and tracking an object in the field of view of the robot under threshold lighting conditions. The VPM includes optical devices for collecting an image of the object, a positional extraction device, and a host machine having an algorithm for processing the image and positional information. The algorithm visually identifies and tracks the object, and automatically adapts an exposure time of the optical devices to prevent feature data loss of the image under the threshold lighting conditions. A method of identifying and tracking the object includes collecting the image, extracting positional information of the object, and automatically adapting the exposure time to thereby prevent feature data loss of the image.

  2. Maintenance Procedures for North American Visually-graded Dimension Lumber Design Values

    Science.gov (United States)

    David Kretschmann; Don DeVisser; Kevin Cheung; Bob Browder; Al Rozek

    2014-01-01

    ASTM International D1990 Standard Practice for Establishing Allowable Properties for Visually-Graded Dimension Lumber from In-Grade Tests of Full-Size Specimens, that governs the development of design values for dimension lumber in North America, was first adopted in 1991with recognition that the resource and manufacturing of lumber could change over time impacting...

  3. Eighth-Grade Violinists' Instrument Tuning Ability: A Comparison of Pitch Perception and Tuning Accuracy

    Science.gov (United States)

    Hopkins, Michael T.

    2015-01-01

    The purpose of this study was to explore the relationship between eighth-grade violinists' pitch perception and instrument tuning skill. The perceptual task was a researcher-developed computer-based Violin Tuning Perception Test. The instrument tuning task involved tuning two violins, one mistuned flat and the other mistuned sharp. Participants (N…

  4. Healthcare Students' Perceptions of Electronic Feedback through GradeMark®

    Science.gov (United States)

    Watkins, Diane; Dummer, Paul; Hawthorne, Kamila; Cousins, Judy; Emmett, Catherine; Johnson, Mike

    2014-01-01

    This paper reports on the findings from a study undertaken to explore students' perceptions of the timeliness, accessibility, consistency, and quality of feedback and grading received electronically. The system used was GradeMark®, an electronic tool available through the plagiarism software provider, Turnitin®. 296 students from the Schools of…

  5. iPad Use in Seventh Grade Math: Parent and Student Perceptions

    Science.gov (United States)

    Corbett, Robin

    2015-01-01

    The purpose of this qualitative research study was to compare student and parental perceptions of mobile technology use, specifically iPads, in seventh grade math classrooms and at home. How students and parents perceive the use of iPads within the seventh grade math classroom and how students and parents perceive the influence of iPad use at home…

  6. Stars advantages vs parallel coordinates: shape perception as visualization reserve

    Science.gov (United States)

    Grishin, Vladimir; Kovalerchuk, Boris

    2013-12-01

    Although shape perception is the main information channel for brain, it has been poor used by recent visualization techniques. The difficulties of its modeling are key obstacles for visualization theory and application. Known experimental estimates of shape perception capabilities have been made for low data dimension, and they were usually not connected with data structures. More applied approach for certain data structures detection by means of shape displays are considered by the example of analytical and experimental comparison of popular now Parallel Coordinates (PCs), i.e. 2D Cartesian displays of data vectors, with polar displays known as stars. Advantages of stars vs. PCs by Gestalt Laws are shown. About twice faster feature selection and classification with stars than PCs are showed by psychological experiments for hyper-tubes structures detection in data space with dimension up to 100-200 and its subspaces. This demonstrates great reserves of visualization enhancement in comparison with many recent techniques usually focused on few data attributes analysis.

  7. Crossmodal Semantic Constraints on Visual Perception of Binocular Rivalry

    Directory of Open Access Journals (Sweden)

    Yi-Chuan Chen

    2011-10-01

    Full Text Available Environments typically convey contextual information via several different sensory modalities. Here, we report a study designed to investigate the crossmodal semantic modulation of visual perception using the binocular rivalry paradigm. The participants viewed a dichoptic figure consisting of a bird and a car presented to each eye, while also listening to either a bird singing or car engine revving. Participants' dominant percepts were modulated by the presentation of a soundtrack associated with either bird or car, as compared to the presentation of a soundtrack irrelevant to both visual figures (tableware clattering together in a restaurant. No such crossmodal semantic effect was observed when the participants maintained an abstract semantic cue in memory. We then further demonstrate that crossmodal semantic modulation can be dissociated from the effects of high-level attentional control over the dichoptic figures and of low-level luminance contrast of the figures. In sum, we demonstrate a novel crossmodal effect in terms of crossmodal semantic congruency on binocular rivalry. This effect can be considered a perceptual grouping or contextual constraint on human visual awareness through mid-level crossmodal excitatory connections embedded in the multisensory semantic network.

  8. Neural bandwidth of veridical perception across the visual field

    Science.gov (United States)

    Wilkinson, Michael O.; Anderson, Roger S.; Bradley, Arthur; Thibos, Larry N.

    2016-01-01

    Neural undersampling of the retinal image limits the range of spatial frequencies that can be represented veridically by the array of retinal ganglion cells conveying visual information from eye to brain. Our goal was to demarcate the neural bandwidth and local anisotropy of veridical perception, unencumbered by optical imperfections of the eye, and to test competing hypotheses that might account for the results. Using monochromatic interference fringes to stimulate the retina with high-contrast sinusoidal gratings, we measured sampling-limited visual resolution along eight meridians from 0° to 50° of eccentricity. The resulting isoacuity contour maps revealed all of the expected features of the human array of retinal ganglion cells. Contours in the radial fringe maps are elongated horizontally, revealing the functional equivalent of the anatomical visual streak, and are extended into nasal retina and superior retina, indicating higher resolution along those meridians. Contours are larger in diameter for radial gratings compared to tangential or oblique gratings, indicating local anisotropy with highest bandwidth for radially oriented gratings. Comparison of these results to anatomical predictions indicates acuity is proportional to the sampling density of retinal ganglion cells everywhere in the retina. These results support the long-standing hypothesis that “pixel density” of the discrete neural image carried by the human optic nerve limits the spatial bandwidth of veridical perception at all retinal locations. PMID:26824638

  9. Human alteration of the rural landscape: Variations in visual perception

    International Nuclear Information System (INIS)

    Cloquell-Ballester, Vicente-Agustín; Carmen Torres-Sibille, Ana del; Cloquell-Ballester, Víctor-Andrés; Santamarina-Siurana, María Cristina

    2012-01-01

    The objective of this investigation is to evaluate how visual perception varies as the rural landscape is altered by human interventions of varying character. An experiment is carried out using Semantic Differential Analysis to analyse the effect of the character and the type of the intervention on perception. Interventions are divided into elements of “permanent industrial character”, “elements of permanent rural character” and “elements of temporary character”, and these categories are sub-divided into smaller groups according to the type of development. To increase the reliability of the results, the Intraclass Correlation Coefficient tool, is applied to validate the semantic space of the perceptual responses and to determine the number of subjects required for a reliable evaluation of the scenes.

  10. Stochastic sensitivity of a bistable energy model for visual perception

    Science.gov (United States)

    Pisarchik, Alexander N.; Bashkirtseva, Irina; Ryashko, Lev

    2017-01-01

    Modern trends in physiology, psychology and cognitive neuroscience suggest that noise is an essential component of brain functionality and self-organization. With adequate noise the brain as a complex dynamical system can easily access different ordered states and improve signal detection for decision-making by preventing deadlocks. Using a stochastic sensitivity function approach, we analyze how sensitive equilibrium points are to Gaussian noise in a bistable energy model often used for qualitative description of visual perception. The probability distribution of noise-induced transitions between two coexisting percepts is calculated at different noise intensity and system stability. Stochastic squeezing of the hysteresis range and its transition from positive (bistable regime) to negative (intermittency regime) are demonstrated as the noise intensity increases. The hysteresis is more sensitive to noise in the system with higher stability.

  11. Tactile and visual perception of injection moulded plastic parts

    DEFF Research Database (Denmark)

    Jensen, Jacob Tobias; Akbas, Erkan; Madsen, Mads

    in today’s products and are very important competition factors. This is also the case for light switches which have been chosen as the object that this assignment with revolve around to exemplify the different plastic materials in use in our daily lives. In the light switch marked for traditional light...... switches the technology is almost the same for all manufactures and therefore the visual appeal is very important as a competition factor. Traditional light switches have the button made from plastic material. It is this button that is imagined to be examined to find a plastic surface with a good visual...... appeal (aesthetics) and tactile perception (ergonomics). From this the following thesis has been created: What plastic material and surface texture gives the best combination of aesthetics and ergonomics in the use for buttons on light switches? Throughout the report this thesis will be examined...

  12. Altering Visual Perception Abnormalities: A Marker for Body Image Concern

    Science.gov (United States)

    Duncum, Anna J. F.; Mundy, Matthew E.

    2016-01-01

    The body image concern (BIC) continuum ranges from a healthy and positive body image, to clinical diagnoses of abnormal body image, like body dysmorphic disorder (BDD). BDD and non-clinical, yet high-BIC participants have demonstrated a local visual processing bias, characterised by reduced inversion effects. To examine whether this bias is a potential marker of BDD, the visual processing of individuals across the entire BIC continuum was examined. Dysmorphic Concern Questionnaire (DCQ; quantified BIC) scores were expected to correlate with higher discrimination accuracy and faster reaction times of inverted stimuli, indicating reduced inversion effects (occurring due to increased local visual processing). Additionally, an induced global or local processing bias via Navon stimulus presentation was expected to alter these associations. Seventy-four participants completed the DCQ and upright-inverted face and body stimulus discrimination task. Moderate positive associations were revealed between DCQ scores and accuracy rates for inverted face and body stimuli, indicating a graded local bias accompanying increases in BIC. This relationship supports a local processing bias as a marker for BDD, which has significant assessment implications. Furthermore, a moderate negative relationship was found between DCQ score and inverted face accuracy after inducing global processing, indicating the processing bias can temporarily be reversed in high BIC individuals. Navon stimuli were successfully able to alter the visual processing of individuals across the BIC continuum, which has important implications for treating BDD. PMID:27003715

  13. Altering Visual Perception Abnormalities: A Marker for Body Image Concern.

    Directory of Open Access Journals (Sweden)

    Francesca L Beilharz

    Full Text Available The body image concern (BIC continuum ranges from a healthy and positive body image, to clinical diagnoses of abnormal body image, like body dysmorphic disorder (BDD. BDD and non-clinical, yet high-BIC participants have demonstrated a local visual processing bias, characterised by reduced inversion effects. To examine whether this bias is a potential marker of BDD, the visual processing of individuals across the entire BIC continuum was examined. Dysmorphic Concern Questionnaire (DCQ; quantified BIC scores were expected to correlate with higher discrimination accuracy and faster reaction times of inverted stimuli, indicating reduced inversion effects (occurring due to increased local visual processing. Additionally, an induced global or local processing bias via Navon stimulus presentation was expected to alter these associations. Seventy-four participants completed the DCQ and upright-inverted face and body stimulus discrimination task. Moderate positive associations were revealed between DCQ scores and accuracy rates for inverted face and body stimuli, indicating a graded local bias accompanying increases in BIC. This relationship supports a local processing bias as a marker for BDD, which has significant assessment implications. Furthermore, a moderate negative relationship was found between DCQ score and inverted face accuracy after inducing global processing, indicating the processing bias can temporarily be reversed in high BIC individuals. Navon stimuli were successfully able to alter the visual processing of individuals across the BIC continuum, which has important implications for treating BDD.

  14. A Ninth Grade Student Transition Model: A Study of Student Perceptions Related to Rigor, Relevancy, and Relationships within a Ninth Grade Transitional Program

    Science.gov (United States)

    Shimp, Timothy M.

    2017-01-01

    This descriptive case study is a qualitative investigation into the perceptions of tenth grade students who experienced a ninth-grade transitional model high school academy within a large PreK-12 suburban school district. Specifically, this study provided the opportunity to examine the success of one Ninth Grade Academy, identify areas of concern…

  15. To Grade or Not to Grade: Student Perceptions of the Effects of Grading a Course in Work-Integrated Learning

    Science.gov (United States)

    Reddan, Gregory

    2013-01-01

    This paper aims to demonstrate the benefits of introducing the typical course grading process to a work-integrated learning course in exercise science in order to motivate students to produce their best efforts in assessment tasks relevant to their future employability. The course had incorporated a non-graded pass/fail system of assessment since…

  16. Quantitative assessment of emphysema from whole lung CT scans: comparison with visual grading

    Science.gov (United States)

    Keller, Brad M.; Reeves, Anthony P.; Apanosovich, Tatiyana V.; Wang, Jianwei; Yankelevitz, David F.; Henschke, Claudia I.

    2009-02-01

    Emphysema is a disease of the lungs that destroys the alveolar air sacs and induces long-term respiratory dysfunction. CT scans allow for imaging of the anatomical basis of emphysema and for visual assessment by radiologists of the extent present in the lungs. Several measures have been introduced for the quantification of the extent of disease directly from CT data in order to add to the qualitative assessments made by radiologists. In this paper we compare emphysema index, mean lung density, histogram percentiles, and the fractal dimension to visual grade in order to evaluate the predictability of radiologist visual scoring of emphysema from low-dose CT scans through quantitative scores, in order to determine which measures can be useful as surrogates for visual assessment. All measures were computed over nine divisions of the lung field (whole lung, individual lungs, and upper/middle/lower thirds of each lung) for each of 148 low-dose, whole lung scans. In addition, a visual grade of each section was also given by an expert radiologist. One-way ANOVA and multinomial logistic regression were used to determine the ability of the measures to predict visual grade from quantitative score. We found that all measures were able to distinguish between normal and severe grades (p<0.01), and between mild/moderate and all other grades (p<0.05). However, no measure was able to distinguish between mild and moderate cases. Approximately 65% prediction accuracy was achieved from using quantitative score to predict visual grade, with 73% if mild and moderate cases are considered as a single class.

  17. 3D sound and 3D image interactions: a review of audio-visual depth perception

    Science.gov (United States)

    Berry, Jonathan S.; Roberts, David A. T.; Holliman, Nicolas S.

    2014-02-01

    There has been much research concerning visual depth perception in 3D stereoscopic displays and, to a lesser extent, auditory depth perception in 3D spatial sound systems. With 3D sound systems now available in a number of different forms, there is increasing interest in the integration of 3D sound systems with 3D displays. It therefore seems timely to review key concepts and results concerning depth perception in such display systems. We first present overviews of both visual and auditory depth perception, before focussing on cross-modal effects in audio-visual depth perception, which may be of direct interest to display and content designers.

  18. Sampling of post-Riley visual artists surreptitiously probing perception

    Science.gov (United States)

    Daly, Scott J.

    2003-06-01

    Attending any conference on visual perception undoubtedly leaves one exposed to the work of Salvador Dali, whose extended phase of work exploring what he dubbed, "the paranoiac-critical method" is very popular as examples of multiple perceptions from conflicting input. While all visual art is intertwined with perceptual science, from convincing three-dimensional illusion during the Renaissance to the isolated visual illusions of Bridget Riley"s Op-Art, direct statements about perception are rarely uttered by the artists in recent times. However, there are still a number of artists working today whose work contains perceptual questions and exemplars that can be of interest to vision scientists and imaging engineers. This talk will start sampling from Op-Art, which is most directly related to psychophysical test stimuli and then will discuss "perceptual installations" from artists such as James Turrell"s, whose focus is often directly on natural light, with no distortions imposed by any capture or display apparatus. His work generally involves installations that use daylight and focus the viewer on its nuanced qualities, such as umbra, air particle interactions, and effects of light adaptation. He is one of the last artists to actively discuss perception. Next we discuss minimal art and electronic art, with video artist Nam June Paik discussing the "intentionally boring" art of minimalism. Another artist using installations is Sandy Skoglund, who creates environments of constant spectral albedo, with the exception of her human occupants. Tom Shannon also uses installations as his media to delve into 3D aspects of depth and perspective, but in an atomized fashion. Beginning with installation concepts, Calvin Collum then adds the restrictive viewpoint of photography to create initially confusing images where the pictorial content and depth features are independent (analogous to the work of Patrick Hughes). Andy Goldsworthy also combines photography with concepts of

  19. Distributed consensus with visual perception in multi-robot systems

    CERN Document Server

    Montijano, Eduardo

    2015-01-01

    This monograph introduces novel responses to the different problems that arise when multiple robots need to execute a task in cooperation, each robot in the team having a monocular camera as its primary input sensor. Its central proposition is that a consistent perception of the world is crucial for the good development of any multi-robot application. The text focuses on the high-level problem of cooperative perception by a multi-robot system: the idea that, depending on what each robot sees and its current situation, it will need to communicate these things to its fellows whenever possible to share what it has found and keep updated by them in its turn. However, in any realistic scenario, distributed solutions to this problem are not trivial and need to be addressed from as many angles as possible. Distributed Consensus with Visual Perception in Multi-Robot Systems covers a variety of related topics such as: ·         distributed consensus algorithms; ·         data association and robustne...

  20. United we sense, divided we fail: context-driven perception of ambiguous visual stimuli

    NARCIS (Netherlands)

    Klink, P. C; van Wezel, Richard Jack Anton; van Ee, R.

    2012-01-01

    Ambiguous visual stimuli provide the brain with sensory information that contains conflicting evidence for multiple mutually exclusive interpretations. Two distinct aspects of the phenomenological experience associated with viewing ambiguous visual stimuli are the apparent stability of perception

  1. Perception of the dynamic visual vertical during sinusoidal linear motion.

    Science.gov (United States)

    Pomante, A; Selen, L P J; Medendorp, W P

    2017-10-01

    The vestibular system provides information for spatial orientation. However, this information is ambiguous: because the otoliths sense the gravitoinertial force, they cannot distinguish gravitational and inertial components. As a consequence, prolonged linear acceleration of the head can be interpreted as tilt, referred to as the somatogravic effect. Previous modeling work suggests that the brain disambiguates the otolith signal according to the rules of Bayesian inference, combining noisy canal cues with the a priori assumption that prolonged linear accelerations are unlikely. Within this modeling framework the noise of the vestibular signals affects the dynamic characteristics of the tilt percept during linear whole-body motion. To test this prediction, we devised a novel paradigm to psychometrically characterize the dynamic visual vertical-as a proxy for the tilt percept-during passive sinusoidal linear motion along the interaural axis (0.33 Hz motion frequency, 1.75 m/s 2 peak acceleration, 80 cm displacement). While subjects ( n =10) kept fixation on a central body-fixed light, a line was briefly flashed (5 ms) at different phases of the motion, the orientation of which had to be judged relative to gravity. Consistent with the model's prediction, subjects showed a phase-dependent modulation of the dynamic visual vertical, with a subject-specific phase shift with respect to the imposed acceleration signal. The magnitude of this modulation was smaller than predicted, suggesting a contribution of nonvestibular signals to the dynamic visual vertical. Despite their dampening effect, our findings may point to a link between the noise components in the vestibular system and the characteristics of dynamic visual vertical. NEW & NOTEWORTHY A fundamental question in neuroscience is how the brain processes vestibular signals to infer the orientation of the body and objects in space. We show that, under sinusoidal linear motion, systematic error patterns appear in the

  2. Visually suboptimal bananas: How ripeness affects consumer expectation and perception.

    Science.gov (United States)

    Symmank, Claudia; Zahn, Susann; Rohm, Harald

    2018-01-01

    One reason for the significant amount of food that is wasted in developed countries is that consumers often expect visually suboptimal food as being less palatable. Using bananas as example, the objective of this study was to determine how appearance affects consumer overall liking, the rating of sensory attributes, purchase intention, and the intended use of bananas. The ripeness degree (RD) of the samples was adjusted to RD 5 (control) and RD 7 (more ripened, visually suboptimal). After preliminary experiments, a total of 233 participants were asked to judge their satisfaction with the intensity of sensory attributes that referred to flavor, taste, and texture using just-about-right scales. Subjects who received peeled samples were asked after tasting, whereas subjects who received unpeeled bananas judged expectation and, after peeling and tasting, perception. Expected overall liking and purchase intention were significantly lower for RD 7 bananas. Purchase intention was still significantly different between RD 5 and RD 7 after tasting, whereas no difference in overall liking was observed. Significant differences between RD 5 and RD 7 were observed when asking participants for their intended use of the bananas. Concerning the sensory attributes, penalty analysis revealed that only the firmness of the RD 7 bananas was still not just-about-right after tasting. The importance that consumers attribute to the shelf-life of food had a pronounced impact on purchase intention of bananas with different ripeness degree. In the case of suboptimal bananas, the results demonstrate a positive relationship between the sensory perception and overall liking and purchase intention. Convincing consumers that visually suboptimal food is still tasty is of high relevance for recommending different ways of communication. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Auditory, visual, and auditory-visual perceptions of emotions by young children with hearing loss versus children with normal hearing.

    Science.gov (United States)

    Most, Tova; Michaelis, Hilit

    2012-08-01

    This study aimed to investigate the effect of hearing loss (HL) on emotion-perception ability among young children with and without HL. A total of 26 children 4.0-6.6 years of age with prelingual sensory-neural HL ranging from moderate to profound and 14 children with normal hearing (NH) participated. They were asked to identify happiness, anger, sadness, and fear expressed by an actress when uttering the same neutral nonsense sentence. Their auditory, visual, and auditory-visual perceptions of the emotional content were assessed. The accuracy of emotion perception among children with HL was lower than that of the NH children in all 3 conditions: auditory, visual, and auditory-visual. Perception through the combined auditory-visual mode significantly surpassed the auditory or visual modes alone in both groups, indicating that children with HL utilized the auditory information for emotion perception. No significant differences in perception emerged according to degree of HL. In addition, children with profound HL and cochlear implants did not perform differently from children with less severe HL who used hearing aids. The relatively high accuracy of emotion perception by children with HL may be explained by their intensive rehabilitation, which emphasizes suprasegmental and paralinguistic aspects of verbal communication.

  4. Perceptions of Climate Change among Grade 11 Learners in the ...

    African Journals Online (AJOL)

    influence the learning process. Keywords: Climate change, school curriculum, learner perceptions, media, peers. Introduction. Climate change is a worldwide issue that is discussed in print and electronic media, as well as on social media. In both the developed and developing world, there is an abundance of.

  5. Grade Inflation: Faculty Lived-Experiences and Perceptions

    Science.gov (United States)

    Schroeder, Nan

    2016-01-01

    The research area of this study is the phenomenon of grade inflation in higher educational organizations. Using a qualitative phenomenological research design, seven faculty members from a higher educational organization were purposefully selected to participate in a semi-structured, face-to-face interview. The participants were of various ages,…

  6. Visual working memory contents bias ambiguous structure from motion perception.

    Directory of Open Access Journals (Sweden)

    Lisa Scocchia

    Full Text Available The way we perceive the visual world depends crucially on the state of the observer. In the present study we show that what we are holding in working memory (WM can bias the way we perceive ambiguous structure from motion stimuli. Holding in memory the percept of an unambiguously rotating sphere influenced the perceived direction of motion of an ambiguously rotating sphere presented shortly thereafter. In particular, we found a systematic difference between congruent dominance periods where the perceived direction of the ambiguous stimulus corresponded to the direction of the unambiguous one and incongruent dominance periods. Congruent dominance periods were more frequent when participants memorized the speed of the unambiguous sphere for delayed discrimination than when they performed an immediate judgment on a change in its speed. The analysis of dominance time-course showed that a sustained tendency to perceive the same direction of motion as the prior stimulus emerged only in the WM condition, whereas in the attention condition perceptual dominance dropped to chance levels at the end of the trial. The results are explained in terms of a direct involvement of early visual areas in the active representation of visual motion in WM.

  7. Olfactory-visual integration facilitates perception of subthreshold negative emotion.

    Science.gov (United States)

    Novak, Lucas R; Gitelman, Darren R; Schuyler, Brianna; Li, Wen

    2015-10-01

    A fast growing literature of multisensory emotion integration notwithstanding, the chemical senses, intimately associated with emotion, have been largely overlooked. Moreover, an ecologically highly relevant principle of "inverse effectiveness", rendering maximal integration efficacy with impoverished sensory input, remains to be assessed in emotion integration. Presenting minute, subthreshold negative (vs. neutral) cues in faces and odors, we demonstrated olfactory-visual emotion integration in improved emotion detection (especially among individuals with weaker perception of unimodal negative cues) and response enhancement in the amygdala. Moreover, while perceptual gain for visual negative emotion involved the posterior superior temporal sulcus/pSTS, perceptual gain for olfactory negative emotion engaged both the associative olfactory (orbitofrontal) cortex and amygdala. Dynamic causal modeling (DCM) analysis of fMRI timeseries further revealed connectivity strengthening among these areas during crossmodal emotion integration. That multisensory (but not low-level unisensory) areas exhibited both enhanced response and region-to-region coupling favors a top-down (vs. bottom-up) account for olfactory-visual emotion integration. Current findings thus confirm the involvement of multisensory convergence areas, while highlighting unique characteristics of olfaction-related integration. Furthermore, successful crossmodal binding of subthreshold aversive cues not only supports the principle of "inverse effectiveness" in emotion integration but also accentuates the automatic, unconscious quality of crossmodal emotion synthesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. A Neural Circuit for Auditory Dominance over Visual Perception.

    Science.gov (United States)

    Song, You-Hyang; Kim, Jae-Hyun; Jeong, Hye-Won; Choi, Ilsong; Jeong, Daun; Kim, Kwansoo; Lee, Seung-Hee

    2017-02-22

    When conflicts occur during integration of visual and auditory information, one modality often dominates the other, but the underlying neural circuit mechanism remains unclear. Using auditory-visual discrimination tasks for head-fixed mice, we found that audition dominates vision in a process mediated by interaction between inputs from the primary visual (VC) and auditory (AC) cortices in the posterior parietal cortex (PTLp). Co-activation of the VC and AC suppresses VC-induced PTLp responses, leaving AC-induced responses. Furthermore, parvalbumin-positive (PV+) interneurons in the PTLp mainly receive AC inputs, and muscimol inactivation of the PTLp or optogenetic inhibition of its PV+ neurons abolishes auditory dominance in the resolution of cross-modal sensory conflicts without affecting either sensory perception. Conversely, optogenetic activation of PV+ neurons in the PTLp enhances the auditory dominance. Thus, our results demonstrate that AC input-specific feedforward inhibition of VC inputs in the PTLp is responsible for the auditory dominance during cross-modal integration. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Effect of Size Change and Brightness Change of Visual Stimuli on Loudness Perception and Pitch Perception of Auditory Stimuli

    Directory of Open Access Journals (Sweden)

    Syouya Tanabe

    2011-10-01

    Full Text Available People obtain a lot of information from visual and auditory sensation on daily life. Regarding the effect of visual stimuli on perception of auditory stimuli, studies of phonological perception and sound localization have been made in great numbers. This study examined the effect of visual stimuli on perception in loudness and pitch of auditory stimuli. We used the image of figures whose size or brightness was changed as visual stimuli, and the sound of pure tone whose loudness or pitch was changed as auditory stimuli. Those visual and auditory stimuli were combined independently to make four types of audio-visual multisensory stimuli for psychophysical experiments. In the experiments, participants judged change in loudness or pitch of auditory stimuli, while they judged the direction of size change or the kind of a presented figure in visual stimuli. Therefore they cannot neglect visual stimuli while they judged auditory stimuli. As a result, perception in loudness and pitch were promoted significantly around their difference limen, when the image was getting bigger or brighter, compared with the case in which the image had no changes. This indicates that perception in loudness and pitch were affected by change in size and brightness of visual stimuli.

  10. Learning Visual Representations for Perception-Action Systems

    DEFF Research Database (Denmark)

    Piater, Justus; Jodogne, Sebastien; Detry, Renaud

    2011-01-01

    and RLJC, our second method learns structural object models for robust object detection and pose estimation by probabilistic inference. To these models, the method associates grasp experiences autonomously learned by trial and error. These experiences form a nonparametric representation of grasp success......We discuss vision as a sensory modality for systems that effect actions in response to perceptions. While the internal representations informed by vision may be arbitrarily complex, we argue that in many cases it is advantageous to link them rather directly to action via learned mappings....... These arguments are illustrated by two examples of our own work. First, our RLVC algorithm performs reinforcement learning directly on the visual input space. To make this very large space manageable, RLVC interleaves the reinforcement learner with a supervised classification algorithm that seeks to split...

  11. A Comparative Study on the Visual Perceptions of Children with Attention Deficit Hyperactivity Disorder

    Science.gov (United States)

    Ahmetoglu, Emine; Aral, Neriman; Butun Ayhan, Aynur

    This study was conducted in order to (a) compare the visual perceptions of seven-year-old children diagnosed with attention deficit hyperactivity disorder with those of normally developing children of the same age and development level and (b) determine whether the visual perceptions of children with attention deficit hyperactivity disorder vary with respect to gender, having received preschool education and parents` educational level. A total of 60 children, 30 with attention deficit hyperactivity disorder and 30 with normal development, were assigned to the study. Data about children with attention deficit hyperactivity disorder and their families was collected by using a General Information Form and the visual perception of children was examined through the Frostig Developmental Test of Visual Perception. The Mann-Whitney U-test and Kruskal-Wallis variance analysis was used to determine whether there was a difference of between the visual perceptions of children with normal development and those diagnosed with attention deficit hyperactivity disorder and to discover whether the variables of gender, preschool education and parents` educational status affected the visual perceptions of children with attention deficit hyperactivity disorder. The results showed that there was a statistically meaningful difference between the visual perceptions of the two groups and that the visual perceptions of children with attention deficit hyperactivity disorder were affected meaningfully by gender, preschool education and parents` educational status.

  12. Multi-agent Orbit Design for Visual Perception Enhancement Purpose

    Directory of Open Access Journals (Sweden)

    Hamidreza Nourzadeh

    2014-10-01

    Full Text Available This paper develops a robust optimization-based method to design orbits on which the sensory perception of the desired physical quantities are maximized. It also demonstrates how to incorporate various constraints imposed by many spacecraft missions, such as collision avoidance, co-orbital configuration, altitude and frozen orbit constraints along with Sun-synchronous orbit constraints. The paper specifically investigates designing orbits for constrained visual sensor planning applications as its case study. For this purpose, the key elements to form an image in such vision systems are considered and effective factors are taken into account to define a metric for perception quality. The method employs a max-min model to ensure robustness against possible perturbations and model uncertainties. While fulfilling the mission requirements, the algorithm devises orbits on which a higher level collective observation quality for the desired sides of the targets is available. The simulation results confirm the effectiveness of the proposed method for several scenarios involving low and medium Earth orbits as well as a challenging space-based space surveillance program application.

  13. The Oral-Aural-Visual Program for Teaching Language Arts: Units of Instruction, Grade Nine.

    Science.gov (United States)

    Indianapolis Public Schools, IN.

    The language program and the six thematic literature units outlined in this oral-aural-visual guide for grade 9 were developed by the Indianapolis Public Schools under Title III, Elementary and Secondary Education Act. The literature units--"Excitement at Your Elbow,""Worlds of the Weird and the Wayout,""Close-Ups,""War and the Individual,""A…

  14. Spatial Visualization as Mediating between Mathematics Learning Strategy and Mathematics Achievement among 8th Grade Students

    Science.gov (United States)

    Rabab'h, Belal; Veloo, Arsaythamby

    2015-01-01

    Jordanian 8th grade students revealed low achievement in mathematics through four periods (1999, 2003, 2007 & 2011) of Trends in International Mathematics and Science Study (TIMSS). This study aimed to determine whether spatial visualization mediates the affect of Mathematics Learning Strategies (MLS) factors namely mathematics attitude,…

  15. CLINICAL AUDIT OF IMAGE QUALITY IN RADIOLOGY USING VISUAL GRADING CHARACTERISTICS ANALYSIS.

    Science.gov (United States)

    Tesselaar, Erik; Dahlström, Nils; Sandborg, Michael

    2016-06-01

    The aim of this work was to assess whether an audit of clinical image quality could be efficiently implemented within a limited time frame using visual grading characteristics (VGC) analysis. Lumbar spine radiography, bedside chest radiography and abdominal CT were selected. For each examination, images were acquired or reconstructed in two ways. Twenty images per examination were assessed by 40 radiology residents using visual grading of image criteria. The results were analysed using VGC. Inter-observer reliability was assessed. The results of the visual grading analysis were consistent with expected outcomes. The inter-observer reliability was moderate to good and correlated with perceived image quality (r(2) = 0.47). The median observation time per image or image series was within 2 min. These results suggest that the use of visual grading of image criteria to assess the quality of radiographs provides a rapid method for performing an image quality audit in a clinical environment. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Visual Literacy Development through the Mediation of Grade 4 English Textbooks

    Science.gov (United States)

    Sibanda, Jabulani; Sibanda, Lucy

    2013-01-01

    The multimodal world learners inhabit demands visual literacy among other literacies if learners are to effectively navigate its terrain. In this study, we sought to understand the extent to which five Grade 4 English textbooks currently used in some schools in the Eastern Cape province of South Africa facilitated the development of visual…

  17. The "School Safety & Security Questionnaire": Middle Grades Students' Perceptions of Safety at School

    Science.gov (United States)

    Miller, Janice Williams; Nickell, Linda K.

    2008-01-01

    This study presents the development and basic psychometric characteristics of the "School Safety and Security Questionnaire" (SSSQ). This new measure was constructed to assess middle grade students' perceptions of safety and security during the school year. The content validity of the theoretically-based instrument was assessed and the measure was…

  18. The Correlation between Student/Instructor Rapport, Student Perceptions of Instructor Effectiveness, and Course Grade Expectations

    Science.gov (United States)

    Yezbick, Erin Lewis

    2016-01-01

    The researcher attempted to determine if a correlation exists between student/instructor rapport, student perceptions of instructor effectiveness, and course grade expectations for freshman general education courses at a career college in the Great Lakes Region of the United States. Previous studies have determined that rapport affects motivation…

  19. Self-Perception of Advanced Mathematical Learners: A Focus on Sixth-Grade Latinos/as

    Science.gov (United States)

    Cavell, Heather A.

    2010-01-01

    The purpose of this dissertation was to analyze the social and educational contexts that impact students' perceptions of their mathematical learning and students' use of resistance in regard to these social and educational impacts within the sixth grade environment. Specifically, this study addressed the following overarching questions: (1) What…

  20. Children's Perceptions of Parental Attitude Affecting Breakfast Skipping in Primary Sixth-Grade Students

    Science.gov (United States)

    Cheng, Tereza Sy; Tse, Lap Ah; Yu, Ignatius Tak-Sun; Griffiths, Sian

    2008-01-01

    Background: Breakfast skipping is an international public health concern. This study investigated the prevalence of breakfast skipping among primary sixth-grade students in Hong Kong and the impact of students' perceptions of parental attitudes on breakfast skipping. Methods: A total of 426 students aged 10-14 years in 4 local schools participated…

  1. Seventh Grade Students' Perceptions of Using Concept Cartoons in Science and Technology Course

    Science.gov (United States)

    Ören, Fatma Sasmaz; Meriç, Gülçin

    2014-01-01

    The aim of this study is to determine the efficiency of use of concept cartoons in elementary school 7th grade students Science and Technology course according to students' perceptions. In terms of this aim, the unit of "Force and Motion" has been taught by concept cartoons and at the end of this period, semi-structured interviews were…

  2. Visual perception in acoustically deprived and normally hearing children.

    Science.gov (United States)

    Thannhauser, Joanna; Buldańczyk, Agnieszka; Salomon, Ewa; Jankowska, Elżbieta; Borodulin-Nadzieja, Ludmiła; Kraszewska, Barbara; Heisig, Monika

    2009-09-01

    In the present study an attempt was made to establish if and to what extent auditory deprivation modifies the processes of visual analysis and synthesis. The study included 54 children aged 10-16 years with hearing impairment attending the School and Educational Center for Children with Hearing Impairment in Wrocław (group I) and 127 children with normal hearing acuity attending public schools (group II), forming a reference group. Hearing impairment in the children of group I was from 60 to 100 dB. In 9 of these children the hearing impairment was inherited, while in some others it was acquired and resulted from rubella during the mother's pregnancy (5 subjects) or a severe disease course in childhood, for instance cerebral meningitis (4 subjects) and otolaryngologic antibiotic therapy (7 subjects). In the remaining subjects the reason for auditory deprivation was unknown. Hearing impairment, apart from genetically conditioned causes, appeared in the first months or years of life. The general intellectual level of the examined children was similar to that of their control counterparts, which was confirmed by school psychologists during a routine examination. The examination was performed by means of two tests from the Nonverbal Score of the Wechsler Intelligence Scale for Children: Puzzles and Block Design. The children with a hearing deficit generally needed more time to perform the tasks than those with normal hearing. The investigated parameters of visual perception improved in correlation with age, but the dynamics of these changes were different in the two study groups.

  3. Visual perception can account for the close relation between numerosity processing and computational fluency

    Directory of Open Access Journals (Sweden)

    Xinlin eZhou

    2015-09-01

    Full Text Available Studies have shown that numerosity processing (e.g., comparison of numbers of dots in two dot arrays is significantly correlated with arithmetic performance. Researchers have attributed this association to the fact that both tasks share magnitude processing. The current investigation tested an visual perception hypothesis that visual perceptual ability (as measured by a figure-matching task can account for the close relation between numerosity processing and arithmetic performance (computational fluency. Four hundred and twenty four third- to fifth-grade children (220 boys and 204 girls, 8.0 to 11.0 years old; 120 third graders, 146 fourth graders, and 158 fifth graders were recruited from two schools (one urban and one suburban in Beijing, China. Six classes were randomly selected from each school, and all students in each selected class were asked to participate in the study. All children were given a series of cognitive and mathematical tests, including numerosity comparison, figure matching, forward verbal working memory, visual tracing, non-verbal matrices reasoning, mental rotation, choice reaction time, arithmetic tests and curriculum-based mathematical achievement test. Results showed that figure-matching ability had higher correlations with numerosity processing and computational fluency than did other cognitive factors (e.g., forward verbal working memory, visual tracing, non-verbal matrices reasoning, mental rotation, and choice reaction time. More important, hierarchical multiple regression showed that figure matching ability accounted for the well-established association between numerosity processing and computational fluency. The results suggest that visual perceptual ability, rather than magnitude processing, may be the shared component of numerosity processing and arithmetic performance.

  4. Assessment of visual health campaign activities at schools: teachers' perception.

    Science.gov (United States)

    Carvalho, Regina de Souza; Temporini, Edméa Rita; Kara-José, Newton

    2007-01-01

    1) To assess the opinion of teachers involved in visual screening of school-age children and their referral to ophthalmologic examination within the "Eye-to-Eye National Campaign for Visual Disorders Prevention and Rehabilitation" (Campanha Nacional de Prevenção e Reabilitação Visual Olho no Olho); 2) To identify the teachers' perception with respect to the training received for conducting the campaign. A descriptive study has been conducted, based on data recorded from the application of a questionnaire to 1,517 elementary school teachers working in public schools in 27 Brazilian states. The following items were examined: received orientation, use of educational videos and handbooks, supplied explanations, difficulties, questions and overall campaign assessment. 82.0% of the teachers stated they had received orientation and 92.0% stated they had read the "Teacher Orientation Manual". Among those who received orientation, 47.0% stated it had been supplied by school officials; 30.0%, by healthcare agents, and 23.0% by ophthalmologists. In the self-assessment of performance, 58.0% reported no difficulties; 32.0% reported questions concerning the campaign activities and the professionals who most frequently asked to provide clarification were those from the State Education Agency (38.0%), followed by the school director (20.0%). Most teachers considered themselves adequately trained and oriented to take part in the campaign. Teachers' training was provided by administrative officials, previously trained by ophthalmologists ("multiplying effect") and the small percentage of questions raised indicated the validity of the procedure. Concerns have been raised as to the information about the ophthalmologic examination, transportation of the children and delivery of glasses. This kind of program always presents some difficulties and requires adjustments. It should, indeed, be improved, perhaps through a closer involvement of the community and families during its

  5. Effects of Auditory Information on Self-Motion Perception during Simultaneous Presentation of Visual Shearing Motion

    OpenAIRE

    Shigehito eTanahashi; Kaoru eAshihara; Hiroyasu eUjike

    2015-01-01

    Recent studies have found that self-motion perception induced by simultaneous presentation of visual and auditory motion is facilitated when the directions of visual and auditory motion stimuli are identical. They did not, however, examine possible contributions of auditory motion information for determining direction of self-motion perception. To examine this, a visual stimulus projected on a hemisphere screen and an auditory stimulus presented through headphones were presented separately or...

  6. Teachers' Perceptions of Developmentally Appropriate Practices in Teaching Reading and Writing for First Grade Students in Kuwait

    Science.gov (United States)

    Al-Dhafir, Mohammad

    2015-01-01

    The purpose of the study was to examine the Kuwaiti first grade teachers' perceptions of developmentally appropriate practices in teaching reading and writing. To achieve the research purpose, a questionnaire was developed and administrated to 167 first grade teachers. Results revealed that first grade teachers hold moderate agreement towards…

  7. Visual perception and memory systems: from cortex to medial temporal lobe.

    Science.gov (United States)

    Khan, Zafar U; Martín-Montañez, Elisa; Baxter, Mark G

    2011-05-01

    Visual perception and memory are the most important components of vision processing in the brain. It was thought that the perceptual aspect of a visual stimulus occurs in visual cortical areas and that this serves as the substrate for the formation of visual memory in a distinct part of the brain called the medial temporal lobe. However, current evidence indicates that there is no functional separation of areas. Entire visual cortical pathways and connecting medial temporal lobe are important for both perception and visual memory. Though some aspects of this view are debated, evidence from both sides will be explored here. In this review, we will discuss the anatomical and functional architecture of the entire system and the implications of these structures in visual perception and memory.

  8. Tuning perception: Visual working memory biases the quality of visual awareness.

    Science.gov (United States)

    Salahub, Christine M; Emrich, Stephen M

    2016-12-01

    Studies of consciousness reveal that it is possible to manipulate subjective awareness of a visual stimulus. For example, items held in visual working memory (VWM) that match target features increase the speed with which the target reaches visual awareness. To examine the effect of VWM on perception, previous studies have mainly used coarse measures of awareness, such as present/absent or forced-choice judgments. These methods can reveal whether or not an individual has seen an item, but they do not provide information about the quality with which the item was seen. Using continuous report methods it has been shown that the fidelity of a perceived item can be affected by whether or not that item is masked. In the present study, we used an object-substitution masking task to examine whether items held in VWM would influence the quality with which a masked target reached awareness, or whether the threshold for awareness was instead affected by stimuli held in memory. We observed that targets matching the contents of VWM were recalled with greater precision compared to items that did not match the contents of VWM. Importantly, this effect occurred without affecting the likelihood of the target being perceived. These results suggest that VWM plays a greater role in modulating the fidelity of perceived representations than in lowering the overall threshold of awareness.

  9. No-reference quality assessment based on visual perception

    Science.gov (United States)

    Li, Junshan; Yang, Yawei; Hu, Shuangyan; Zhang, Jiao

    2014-11-01

    The visual quality assessment of images/videos is an ongoing hot research topic, which has become more and more important for numerous image and video processing applications with the rapid development of digital imaging and communication technologies. The goal of image quality assessment (IQA) algorithms is to automatically assess the quality of images/videos in agreement with human quality judgments. Up to now, two kinds of models have been used for IQA, namely full-reference (FR) and no-reference (NR) models. For FR models, IQA algorithms interpret image quality as fidelity or similarity with a perfect image in some perceptual space. However, the reference image is not available in many practical applications, and a NR IQA approach is desired. Considering natural vision as optimized by the millions of years of evolutionary pressure, many methods attempt to achieve consistency in quality prediction by modeling salient physiological and psychological features of the human visual system (HVS). To reach this goal, researchers try to simulate HVS with image sparsity coding and supervised machine learning, which are two main features of HVS. A typical HVS captures the scenes by sparsity coding, and uses experienced knowledge to apperceive objects. In this paper, we propose a novel IQA approach based on visual perception. Firstly, a standard model of HVS is studied and analyzed, and the sparse representation of image is accomplished with the model; and then, the mapping correlation between sparse codes and subjective quality scores is trained with the regression technique of least squaresupport vector machine (LS-SVM), which gains the regressor that can predict the image quality; the visual metric of image is predicted with the trained regressor at last. We validate the performance of proposed approach on Laboratory for Image and Video Engineering (LIVE) database, the specific contents of the type of distortions present in the database are: 227 images of JPEG2000, 233

  10. Perceptions of the Visually Impaired toward Pursuing Geography Courses and Majors in Higher Education

    Science.gov (United States)

    Murr, Christopher D.; Blanchard, R. Denise

    2011-01-01

    Advances in classroom technology have lowered barriers for the visually impaired to study geography, yet few participate. Employing stereotype threat theory, we examined whether beliefs held by the visually impaired affect perceptions toward completing courses and majors in visually oriented disciplines. A test group received a low-level threat…

  11. Protoporphyrin-IX fluorescence guided surgical resection in high-grade gliomas: The potential impact of human colour perception.

    Science.gov (United States)

    Petterssen, Max; Eljamel, Sarah; Eljamel, Sam

    2014-09-01

    Protoporphyrin-IX (Pp-IX) fluorescence had been used frequently in recent years to guide microsurgical resection of high-grade gliomas (HGG), particularly following the publication of a randomized controlled trial demonstrating its advantages. However, Pp-IX fluorescence is dependent upon the surgeons' eyes' perception of red fluorescent colour. This study was designed to evaluate human eye fluorescence perception and establish a fluorescence scale. 20 of 108 pre-recorded images from intraoperative fluorescence of HGG were used to construct an 8-panel visual analogue fluorescence scale. The scale was validated by testing 56 participants with normal colour vision and three red-green colour-blind participants. For intra-rater agreement ten participants were tested twice and for inter-observer reliability the whole cohort were tested. The intra- and inter-observer reliability of the scale in normal colour vision participants was excellent. The scale was less reliable in the violet-blue panels of the scale. Colour-blind participants were not able to distinguish between red fluorescence and blue-violet colours. The 8-panel fluorescence scale is valid in differentiating red, pink and blue colours in a fluorescence surgical field among participants with normal colour perception and potentially useful to standardize fluorescence-guided surgery. However, colourblind surgeons should not use fluorescence-guided surgery. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. PERCEPT Indoor Navigation System for the Blind and Visually Impaired: Architecture and Experimentation

    Directory of Open Access Journals (Sweden)

    Aura Ganz

    2012-01-01

    Full Text Available We introduce PERCEPT system, an indoor navigation system for the blind and visually impaired. PERCEPT will improve the quality of life and health of the visually impaired community by enabling independent living. Using PERCEPT, blind users will have independent access to public health facilities such as clinics, hospitals, and wellness centers. Access to healthcare facilities is crucial for this population due to the multiple health conditions that they face such as diabetes and its complications. PERCEPT system trials with 24 blind and visually impaired users in a multistory building show PERCEPT system effectiveness in providing appropriate navigation instructions to these users. The uniqueness of our system is that it is affordable and that its design follows orientation and mobility principles. We hope that PERCEPT will become a standard deployed in all indoor public spaces, especially in healthcare and wellness facilities.

  13. PERCEPT Indoor Navigation System for the Blind and Visually Impaired: Architecture and Experimentation.

    Science.gov (United States)

    Ganz, Aura; Schafer, James; Gandhi, Siddhesh; Puleo, Elaine; Wilson, Carole; Robertson, Meg

    2012-01-01

    We introduce PERCEPT system, an indoor navigation system for the blind and visually impaired. PERCEPT will improve the quality of life and health of the visually impaired community by enabling independent living. Using PERCEPT, blind users will have independent access to public health facilities such as clinics, hospitals, and wellness centers. Access to healthcare facilities is crucial for this population due to the multiple health conditions that they face such as diabetes and its complications. PERCEPT system trials with 24 blind and visually impaired users in a multistory building show PERCEPT system effectiveness in providing appropriate navigation instructions to these users. The uniqueness of our system is that it is affordable and that its design follows orientation and mobility principles. We hope that PERCEPT will become a standard deployed in all indoor public spaces, especially in healthcare and wellness facilities.

  14. Visual Form Perception Can Be a Cognitive Correlate of Lower Level Math Categories for Teenagers

    Science.gov (United States)

    Cui, Jiaxin; Zhang, Yiyun; Cheng, Dazhi; Li, Dawei; Zhou, Xinlin

    2017-01-01

    Numerous studies have assessed the cognitive correlates of performance in mathematics, but little research has been conducted to systematically examine the relations between visual perception as the starting point of visuospatial processing and typical mathematical performance. In the current study, we recruited 223 seventh graders to perform a visual form perception task (figure matching), numerosity comparison, digit comparison, exact computation, approximate computation, and curriculum-based mathematical achievement tests. Results showed that, after controlling for gender, age, and five general cognitive processes (choice reaction time, visual tracing, mental rotation, spatial working memory, and non-verbal matrices reasoning), visual form perception had unique contributions to numerosity comparison, digit comparison, and exact computation, but had no significant relation with approximate computation or curriculum-based mathematical achievement. These results suggest that visual form perception is an important independent cognitive correlate of lower level math categories, including the approximate number system, digit comparison, and exact computation. PMID:28824513

  15. Peripersonal versus extrapersonal visual scene information for egocentric direction and position perception.

    Science.gov (United States)

    Nakashima, Ryoichi; Kumada, Takatsune

    2017-03-22

    When perceiving the visual environment, people simultaneously perceive their own direction and position in the environment (i.e., egocentric spatial perception). This study investigated what visual information in a scene is necessary for egocentric spatial perceptions. In two perception tasks (the egocentric direction and position perception tasks), observers viewed two static road images presented sequentially. In Experiment 1, the critical manipulation involved an occluded region in the road image; an extrapersonal region (far-occlusion) and a peripersonal region (near-occlusion). Egocentric direction perception was the poorer in the far-occlusion condition than in the no-occlusion condition, and egocentric position perceptions were poorer in the far- and near-occlusion conditions than in the no-occlusion condition. In Experiment 2, we conducted the same tasks manipulating the observers' gaze location in a scene; an extrapersonal region (far-gaze), a peripersonal region (near-gaze) and the intermediate region between the former two (middle-gaze). Egocentric direction perception performance was the best in the far-gaze condition, and egocentric position perception performances were not different among gaze location conditions. These results suggest that egocentric direction perception is based on fine visual information about the extrapersonal region in a road landscape, and egocentric position perception is based on information about the entire visual scene.

  16. Direct Contribution of Auditory Motion Information to Sound-Induced Visual Motion Perception

    Directory of Open Access Journals (Sweden)

    Souta Hidaka

    2011-10-01

    Full Text Available We have recently demonstrated that alternating left-right sound sources induce motion perception to static visual stimuli along the horizontal plane (SIVM: sound-induced visual motion perception, Hidaka et al., 2009. The aim of the current study was to elucidate whether auditory motion signals, rather than auditory positional signals, can directly contribute to the SIVM. We presented static visual flashes at retinal locations outside the fovea together with a lateral auditory motion provided by a virtual stereo noise source smoothly shifting in the horizontal plane. The flashes appeared to move in the situation where auditory positional information would have little influence on the perceived position of visual stimuli; the spatiotemporal position of the flashes was in the middle of the auditory motion trajectory. Furthermore, the auditory motion altered visual motion perception in a global motion display; in this display, different localized motion signals of multiple visual stimuli were combined to produce a coherent visual motion perception so that there was no clear one-to-one correspondence between the auditory stimuli and each visual stimulus. These findings suggest the existence of direct interactions between the auditory and visual modalities in motion processing and motion perception.

  17. Combining spatial and temporal expectations to improve visual perception.

    Science.gov (United States)

    Rohenkohl, Gustavo; Gould, Ian C; Pessoa, Jéssica; Nobre, Anna C

    2014-04-10

    The importance of temporal expectations in modulating perceptual functions is increasingly recognized. However, the means through which temporal expectations can bias perceptual information processing remains ill understood. Recent theories propose that modulatory effects of temporal expectations rely on the co-existence of other biases based on receptive-field properties, such as spatial location. We tested whether perceptual benefits of temporal expectations in a perceptually demanding psychophysical task depended on the presence of spatial expectations. Foveally presented symbolic arrow cues indicated simultaneously where (location) and when (time) target events were more likely to occur. The direction of the arrow indicated target location (80% validity), while its color (pink or blue) indicated the interval (80% validity) for target appearance. Our results confirmed a strong synergistic interaction between temporal and spatial expectations in enhancing visual discrimination. Temporal expectation significantly boosted the effectiveness of spatial expectation in sharpening perception. However, benefits for temporal expectation disappeared when targets occurred at unattended locations. Our findings suggest that anticipated receptive-field properties of targets provide a natural template upon which temporal expectations can operate in order to help prioritize goal-relevant events from early perceptual stages.

  18. The Perception of Cooperativeness Without Any Visual or Auditory Communication.

    Science.gov (United States)

    Chang, Dong-Seon; Burger, Franziska; Bülthoff, Heinrich H; de la Rosa, Stephan

    2015-12-01

    Perceiving social information such as the cooperativeness of another person is an important part of human interaction. But can people perceive the cooperativeness of others even without any visual or auditory information? In a novel experimental setup, we connected two people with a rope and made them accomplish a point-collecting task together while they could not see or hear each other. We observed a consistently emerging turn-taking behavior in the interactions and installed a confederate in a subsequent experiment who either minimized or maximized this behavior. Participants experienced this only through the haptic force-feedback of the rope and made evaluations about the confederate after each interaction. We found that perception of cooperativeness was significantly affected only by the manipulation of this turn-taking behavior. Gender- and size-related judgments also significantly differed. Our results suggest that people can perceive social information such as the cooperativeness of other people even in situations where possibilities for communication are minimal.

  19. Performance in a Visual Search Task Uniquely Predicts Reading Abilities in Third-Grade Hong Kong Chinese Children

    Science.gov (United States)

    Liu, Duo; Chen, Xi; Chung, Kevin K. H.

    2015-01-01

    This study examined the relation between the performance in a visual search task and reading ability in 92 third-grade Hong Kong Chinese children. The visual search task, which is considered a measure of visual-spatial attention, accounted for unique variance in Chinese character reading after controlling for age, nonverbal intelligence,…

  20. The Perceptual Root of Object-Based Storage: An Interactive Model of Perception and Visual Working Memory

    Science.gov (United States)

    Gao, Tao; Gao, Zaifeng; Li, Jie; Sun, Zhongqiang; Shen, Mowei

    2011-01-01

    Mainstream theories of visual perception assume that visual working memory (VWM) is critical for integrating online perceptual information and constructing coherent visual experiences in changing environments. Given the dynamic interaction between online perception and VWM, we propose that how visual information is processed during visual…

  1. Grading of carotid artery stenosis with multidetector-row CT angiography: visual estimation or caliper measurements?

    Science.gov (United States)

    Waaijer, Annet; Weber, M; van Leeuwen, M S; Kardux, J; Veldhuis, W B; Lo, R; Beek, F J A; Prokop, M

    2009-12-01

    To assess the optimal method for grading carotid artery stenosis with computed tomographic angiography (CTA), we compared visual estimation to caliper measurements, and determined inter-observer variability and agreement relative to digital subtraction angiography (DSA). We included 46 patients with symptomatic carotid stenosis for whom CTA and DSA of 55 carotids was available. Stenosis quantification by CTA using visual estimation (CTA(VE)) (method 1) was compared with caliper measurements using subjectively optimized wide window settings (method 2) or predefined contrast-dependent narrow window settings (method 3). Measurements were independently performed by two radiologists and two residents. To determine accuracy and inter-observer variability, we calculated linear weighted kappa, performed a Bland-Altman analysis and calculated mean difference (bias) and standard deviation of differences (SDD). For inter-observer variability, kappa analysis was "very good" (0.85) for expert observers using CTA(VE) compared with "good" (0.61) for experts using DSA. Compared with DSA, method 1 led to overestimation (bias 5.8-8.0%, SDD 10.6-14.4), method 3 led to underestimation (bias -6.3 to -3.0%, SDD 13.0-18.1). Measurement variability between DSA and visual estimation on CTA (SDD 11.5) is close to the inter-observer variability of repeated measurements on DSA that we found in this study (SDD 11.6). For CTA of carotids, stenosis grading based on visual estimation provides better agreement to grading by DSA compared with stenosis grading based on caliper measurements.

  2. Neural mechanisms underlying sound-induced visual motion perception: An fMRI study.

    Science.gov (United States)

    Hidaka, Souta; Higuchi, Satomi; Teramoto, Wataru; Sugita, Yoichi

    2017-07-01

    Studies of crossmodal interactions in motion perception have reported activation in several brain areas, including those related to motion processing and/or sensory association, in response to multimodal (e.g., visual and auditory) stimuli that were both in motion. Recent studies have demonstrated that sounds can trigger illusory visual apparent motion to static visual stimuli (sound-induced visual motion: SIVM): A visual stimulus blinking at a fixed location is perceived to be moving laterally when an alternating left-right sound is also present. Here, we investigated brain activity related to the perception of SIVM using a 7T functional magnetic resonance imaging technique. Specifically, we focused on the patterns of neural activities in SIVM and visually induced visual apparent motion (VIVM). We observed shared activations in the middle occipital area (V5/hMT), which is thought to be involved in visual motion processing, for SIVM and VIVM. Moreover, as compared to VIVM, SIVM resulted in greater activation in the superior temporal area and dominant functional connectivity between the V5/hMT area and the areas related to auditory and crossmodal motion processing. These findings indicate that similar but partially different neural mechanisms could be involved in auditory-induced and visually-induced motion perception, and neural signals in auditory, visual, and, crossmodal motion processing areas closely and directly interact in the perception of SIVM. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Anatomy-Correlated Breast Imaging and Visual Grading Analysis Using Quantitative Transmission Ultrasound™

    Directory of Open Access Journals (Sweden)

    John C. Klock

    2016-01-01

    Full Text Available Objectives. This study presents correlations between cross-sectional anatomy of human female breasts and Quantitative Transmission (QT Ultrasound, does discriminate classifier analysis to validate the speed of sound correlations, and does a visual grading analysis comparing QT Ultrasound with mammography. Materials and Methods. Human cadaver breasts were imaged using QT Ultrasound, sectioned, and photographed. Biopsies confirmed microanatomy and areas were correlated with QT Ultrasound images. Measurements were taken in live subjects from QT Ultrasound images and values of speed of sound for each identified anatomical structure were plotted. Finally, a visual grading analysis was performed on images to determine whether radiologists’ confidence in identifying breast structures with mammography (XRM is comparable to QT Ultrasound. Results. QT Ultrasound identified all major anatomical features of the breast, and speed of sound calculations showed specific values for different breast tissues. Using linear discriminant analysis overall accuracy is 91.4%. Using visual grading analysis readers scored the image quality on QT Ultrasound as better than on XRM in 69%–90% of breasts for specific tissues. Conclusions. QT Ultrasound provides accurate anatomic information and high tissue specificity using speed of sound information. Quantitative Transmission Ultrasound can distinguish different types of breast tissue with high resolution and accuracy.

  4. A Survey on Visual Perception for RoboCup MSL Soccer Robots

    Directory of Open Access Journals (Sweden)

    Xun Li

    2013-02-01

    Full Text Available Visual perception is the most important method for providing information about the competition environment for RoboCup Middle Size League (MSL soccer robots. The paper reviews the advancement of visual perception in RoboCup MSL soccer robots from several points of view including the design and calibration of the vision system, the visual object recognition, the estimation of the object's motion, robot visual self-localization and multi-robot cooperative sensing. The research progress we have achieved is also introduced in this review. The developing trends and the future research focuses on this problem are also discussed.

  5. Visual Temporal Acuity Is Related to Auditory Speech Perception Abilities in Cochlear Implant Users.

    Science.gov (United States)

    Jahn, Kelly N; Stevenson, Ryan A; Wallace, Mark T

    Despite significant improvements in speech perception abilities following cochlear implantation, many prelingually deafened cochlear implant (CI) recipients continue to rely heavily on visual information to develop speech and language. Increased reliance on visual cues for understanding spoken language could lead to the development of unique audiovisual integration and visual-only processing abilities in these individuals. Brain imaging studies have demonstrated that good CI performers, as indexed by auditory-only speech perception abilities, have different patterns of visual cortex activation in response to visual and auditory stimuli as compared with poor CI performers. However, no studies have examined whether speech perception performance is related to any type of visual processing abilities following cochlear implantation. The purpose of the present study was to provide a preliminary examination of the relationship between clinical, auditory-only speech perception tests, and visual temporal acuity in prelingually deafened adult CI users. It was hypothesized that prelingually deafened CI users, who exhibit better (i.e., more acute) visual temporal processing abilities would demonstrate better auditory-only speech perception performance than those with poorer visual temporal acuity. Ten prelingually deafened adult CI users were recruited for this study. Participants completed a visual temporal order judgment task to quantify visual temporal acuity. To assess auditory-only speech perception abilities, participants completed the consonant-nucleus-consonant word recognition test and the AzBio sentence recognition test. Results were analyzed using two-tailed partial Pearson correlations, Spearman's rho correlations, and independent samples t tests. Visual temporal acuity was significantly correlated with auditory-only word and sentence recognition abilities. In addition, proficient CI users, as assessed via auditory-only speech perception performance, demonstrated

  6. Medical and pharmacy students' perceptions of the grading and assessment practices

    OpenAIRE

    Kasanda, C. D.; Mitonga, K. H.; Veii, K.; Zimba, R. F.

    2013-01-01

    Many students at the University of Namibia have frequently complained about ineffective assessment practices used at the institution. On many occasions, these complaints have not been substantiated with evidence of any kind. The purpose of this study was to obtain some empirical evidence that would ascertain undergraduate students' perceptions of the University of Namibia's grading and assessment practices. Using a structured scaled questionnaire, data were obtained from a representative samp...

  7. The effects of pattern shape, subliminal stimulation, and voluntary control on multistable visual perception

    Czech Academy of Sciences Publication Activity Database

    Taddei-Ferretti, C.; Radilová, Jiřina; Musio, C.; Santillo, S.; Cibelli, E.; Cotugno, A.; Radil, Tomáš

    2008-01-01

    Roč. 1225, - (2008), s. 163-170 ISSN 0006-8993 Institutional research plan: CEZ:AV0Z50110509 Keywords : visual perception * figure reversal Subject RIV: FH - Neurology Impact factor: 2.494, year: 2008

  8. Visual and auditory perception in preschool children at risk for dyslexia.

    Science.gov (United States)

    Ortiz, Rosario; Estévez, Adelina; Muñetón, Mercedes; Domínguez, Carolina

    2014-11-01

    Recently, there has been renewed interest in perceptive problems of dyslexics. A polemic research issue in this area has been the nature of the perception deficit. Another issue is the causal role of this deficit in dyslexia. Most studies have been carried out in adult and child literates; consequently, the observed deficits may be the result rather than the cause of dyslexia. This study addresses these issues by examining visual and auditory perception in children at risk for dyslexia. We compared children from preschool with and without risk for dyslexia in auditory and visual temporal order judgment tasks and same-different discrimination tasks. Identical visual and auditory, linguistic and nonlinguistic stimuli were presented in both tasks. The results revealed that the visual as well as the auditory perception of children at risk for dyslexia is impaired. The comparison between groups in auditory and visual perception shows that the achievement of children at risk was lower than children without risk for dyslexia in the temporal tasks. There were no differences between groups in auditory discrimination tasks. The difficulties of children at risk in visual and auditory perceptive processing affected both linguistic and nonlinguistic stimuli. Our conclusions are that children at risk for dyslexia show auditory and visual perceptive deficits for linguistic and nonlinguistic stimuli. The auditory impairment may be explained by temporal processing problems and these problems are more serious for processing language than for processing other auditory stimuli. These visual and auditory perceptive deficits are not the consequence of failing to learn to read, thus, these findings support the theory of temporal processing deficit. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Opposite Distortions in Interval Timing Perception for Visual and Auditory Stimuli with Temporal Modulations.

    Science.gov (United States)

    Yuasa, Kenichi; Yotsumoto, Yuko

    2015-01-01

    When an object is presented visually and moves or flickers, the perception of its duration tends to be overestimated. Such an overestimation is called time dilation. Perceived time can also be distorted when a stimulus is presented aurally as an auditory flutter, but the mechanisms and their relationship to visual processing remains unclear. In the present study, we measured interval timing perception while modulating the temporal characteristics of visual and auditory stimuli, and investigated whether the interval times of visually and aurally presented objects shared a common mechanism. In these experiments, participants compared the durations of flickering or fluttering stimuli to standard stimuli, which were presented continuously. Perceived durations for auditory flutters were underestimated, while perceived durations of visual flickers were overestimated. When auditory flutters and visual flickers were presented simultaneously, these distortion effects were cancelled out. When auditory flutters were presented with a constantly presented visual stimulus, the interval timing perception of the visual stimulus was affected by the auditory flutters. These results indicate that interval timing perception is governed by independent mechanisms for visual and auditory processing, and that there are some interactions between the two processing systems.

  10. Neurovisual training (TRIGRAM in young patients with visual-perceptive dyslexia

    Directory of Open Access Journals (Sweden)

    Fernanda Pacella

    2017-01-01

    Full Text Available Dyslexia is a language-based learning disability. Although this condition is characterized by anatomical malformation of the brain, it seems that the typical reading pattern of dyslexic may be also related to more complex sensory deficits. Among them, visual-perceptive deficits have been described in a subtype of dyslexia, called visual-perceptive dyslexia. The distinctive feature of a patient suffering from visual-perceptive dyslexia form is marked by effortlessly recognize the characteristics of each individual stimulus. The Tetra protocol is a visual-perceptual evaluation protocol that was introduced for the diagnostic phase and the rehabilitation of visual-perceptive dyslexia. The diagnostic tests include: the eidomorphometry test, designed to evaluate the perception of spatial relationships; the contrast sensitivity threshold test, especially at low spatial frequencies; and the REPORT TEST words, to assess the speed and the reading efficiency. In addition, the rehabilitation phase is carried out with the visual neuro-enhancement program TRIGRAM, a visual training proposal designed to reduce the lateral masking phenomenon in visual-perceptive dyslexic. Thus, in this study we used the diagnostic tests of TETRA® Protocol to determine presence of visual-perceptual abnormalities in children with dyslexia. Proven time the presence of these visual-perceptual alterations, the patients were also subjected to the rehabilitation sessions of TRIGRAM, in order to investigate whether this visual training may improve the pattern of reading. At the end of the program (t1 and after three months (t2, the same subjects underwent the same diagnostic tests of TETRA® Protocol to evaluate and confirm the results obtained during rehabilitation program. The results showed a significant increase in contrast sensitivity at low and high spatial frequencies. Moreover, the same improvements in the visual system's ability to discriminate the contours of an object

  11. The influence of auditory and visual information on the perception of crispy food

    NARCIS (Netherlands)

    Pocztaruk, R.D.; Abbink, J.H.; Wijk, de R.A.; Frasca, L.C.D.; Gaviao, M.B.D.; Bilt, van de A.

    2011-01-01

    The influence of auditory and/or visual information on the perception of crispy food and on the physiology of chewing was investigated. Participants chewed biscuits of three different levels of crispness under four experimental conditions: no masking, auditory masking, visual masking, and auditory

  12. Role of visual integration in gaze perception and emotional intelligence in schizophrenia.

    Science.gov (United States)

    Tso, Ivy F; Carp, Joshua; Taylor, Stephan F; Deldin, Patricia J

    2014-05-01

    Individuals with schizophrenia demonstrate a wide range of social cognitive deficits that significantly compromise functioning. Early visual processing is frequently disrupted in schizophrenia, and growing evidence suggests a role of perceptual dysfunctions in socioemotional functioning in the disorder. This study examined visual integration (the ability to effectively integrate individual, local visual features into a holistic representation), a target construct of basic perception identified by the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia initiative, and its relationship with eye- contact perception and emotional intelligence in schizophrenia. Twenty-nine participants with schizophrenia (SCZ) and 23 healthy controls (HC) completed tasks measuring visual integration (Coherent Motion Task, Contour Integration Task), an eye-contact perception task, and a measure of emotional intelligence. SCZ participants showed compromised visual integration as suggested by poorer performance on the Contour Integration Task relative to HC. Visual integration was a significant predictor of eye-contact perception and emotional intelligence among SCZ. The amounts of variances in these 2 social cognitive areas accounted for by visual integration were comparable to and overlapped with those accounted for by the diagnosis of schizophrenia. Individuals with schizophrenia showed compromised visual integration, and this may play a significant role in the observed deficits in higher level processing of social information in the disorder.

  13. Parents' Perceptions of Physical Activity for Their Children with Visual Impairments

    Science.gov (United States)

    Perkins, Kara; Columna, Luis; Lieberman, Lauren; Bailey, JoEllen

    2013-01-01

    Introduction: Ongoing communication with parents and the acknowledgment of their preferences and expectations are crucial to promote the participation of physical activity by children with visual impairments. Purpose: The study presented here explored parents' perceptions of physical activity for their children with visual impairments and explored…

  14. Biometric Research in Perception and Neurology Related to the Study of Visual Communication.

    Science.gov (United States)

    Metallinos, Nikos

    Contemporary research findings in the fields of perceptual psychology and neurology of the human brain that are directly related to the study of visual communication are reviewed and briefly discussed in this paper. Specifically, the paper identifies those major research findings in visual perception that are relevant to the study of visual…

  15. Validity and Reliability of the Developmental Test of Visual Perception - Third Edition (DTVP-3).

    Science.gov (United States)

    Brown, Ted

    2016-07-01

    The Developmental Test of Visual Perception - Third Edition (DTVP-3) is a recently published revision of a visual perceptual test from the United States, frequently used by occupational therapists. It is important that tests have adequate documented reliability and validity and are evaluated in cross-cultural contexts. The purpose of the study was to assess the reliability and validity of the DTVP-3 when completed by a group of Australian participants. Thirty-nine typically developing children 6-8 years of age completed the DTVP-3 and the Developmental Test of Visual-Motor Integration - 6th edition (VMI-6). The internal consistency of the DVTP-3 was assessed using Cronbach alpha coefficients and the DTVP-3's convergent validity was examined by correlating it with the VMI-6 and its two supplementary tests. The five DTVP-3 subscales' Cronbach alpha coefficients ranged from.60 to.80 while its three composite indexes had coefficients all at the.80 level. The VMI-6 was significantly correlated with the DTVP-3 Figure Ground and Visual Closure subscales and the Motor-Reduced Visual Perception Index (MRVPI). The VMI-6 Visual Perception Supplementary Test was significantly correlated with the DTVP-3 Figure Ground, Visual Closure, Form Constancy, MRVPI, and General Visual Perception Index. The DTVP-3 exhibited acceptable levels of internal consistency and moderate levels of convergent validity with the VMI-6 when completed by a group of Australian children.

  16. Hemispheric differences in electrical and hemodynamic responses during hemifield visual stimulation with graded contrasts.

    Science.gov (United States)

    Si, Juanning; Zhang, Xin; Zhang, Yujin; Jiang, Tianzi

    2017-04-01

    A multimodal neuroimaging technique based on electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) was used with horizontal hemifield visual stimuli with graded contrasts to investigate the retinotopic mapping more fully as well as to explore hemispheric differences in neuronal activity, the hemodynamic response, and the neurovascular coupling relationship in the visual cortex. The fNIRS results showed the expected activation over the contralateral hemisphere for both the left and right hemifield visual stimulations. However, the EEG results presented a paradoxical lateralization, with the maximal response located over the ipsilateral hemisphere but with the polarity inversed components located over the contralateral hemisphere. Our results suggest that the polarity inversion as well as the latency advantage over the contralateral hemisphere cause the amplitude of the VEP over the contralateral hemisphere to be smaller than that over the ipsilateral hemisphere. Both the neuronal and hemodynamic responses changed logarithmically with the level of contrast in the hemifield visual stimulations. Moreover, the amplitudes and latencies of the visual evoked potentials (VEPs) were linearly correlated with the hemodynamic responses despite differences in the slopes.

  17. Improving the spelling ability of Grade 3 learners through visual imaging teaching strategies

    Directory of Open Access Journals (Sweden)

    Van Staden, Annalene

    2010-12-01

    Full Text Available This paper discusses two key cognitive theories underlying spelling acquisition, i.e. the developmental stage theory and the overlapping waves theory. Within the developmental stage framework, learning to spell is viewed as a process of moving from spelling that represents sound to spelling that represents meaning, following a sequence of qualitatively distinct stages in a linear fashion. In contrast, proponents of the overlapping waves theory emphasise the use of different instructional approaches at any given time. This model is process-orientated and stresses the adaptation of strategies to meet the needs of the task. Other researchers maintain that spelling is a natural process and emphasise the importance of invented spelling practices and creative writing embedded in whole-language programmes. There is, however, a lack of research validating the efficacy of an exclusively naturalistic approach to spelling. In general, research findings support a combination of incidental learning and direct instruction as most beneficial for learners with spelling problems. Thus, this study was undertaken to develop a visual imagery programme for Grade 3 learners by compromising between direct instruction in specific spelling skills (i.e. visual imaging strategies whilst also immersing learners in meaningful authentic reading activities. It was hypothesised that the spelling abilities of Afrikaans-speaking Grade 3 learners can be improved significantly by exposing them to a spelling programme that focuses on visual imaging, immediate feedback and self-correcting strategies. Researchers opposed to visual teaching methods for spelling moreover postulate, among other things, that learners with auditory preferences will not benefit from a visual approach to the teaching of spelling. In this empirical study the possible relation between preferential learning styles and spelling performance was also investigated.

  18. The Relationship between Grade 11 Palestinian Attitudes toward Biology and Their Perceptions of the Biology Learning Environment

    Science.gov (United States)

    Zeidan, Afif

    2010-01-01

    The aims of the study were to investigate (a) the relationship between the attitudes toward biology and perceptions of the biology learning environment among grade 11 students in Tulkarm District, Palestine and (b) the effect of gender and residence of these students on their attitudes toward biology and on their perceptions of the biology…

  19. Promoting a Pedagogy for Listening Instruction: Primary Grade Teachers Perceptions of Teaching Listening through Interactive Read Alouds

    Science.gov (United States)

    Fogelsong, Donna Fortune

    2016-01-01

    This study was designed to investigate teachers' perceptions about instructing listening in second-grade classrooms. Children's literature that included specific listening content was used to explore how the teachers' perceptions influenced planning read alouds for explicitly teaching listening skills. Investigations included: (1) What were…

  20. A Phenomenological Investigation of Male At-Risk Sixth, Seventh and Eighth Grade Students' Perceptions toward Reading

    Science.gov (United States)

    Douma, Jason Scott

    2012-01-01

    The purpose of this phenomenological study was to investigate the perceptions that male at-risk sixth, seventh and eighth grade students' possess toward reading at a small rural public school district in Michigan. Male at-risk students was generally defined as students below grade level in reading based on their STAR reading assessment. Male…

  1. Graded changes in balancing behavior as a function of visual acuity.

    Science.gov (United States)

    Schmid, M; Casabianca, L; Bottaro, A; Schieppati, M

    2008-06-02

    In a dynamic postural task, visual information plays a fundamental role in the selection of the balancing strategy. While standing on a platform oscillating in the antero-posterior direction, subjects almost fix their head in space when vision is allowed and oscillate with the platform with eyes closed. We investigated two competing hypotheses regarding the relationship between visual acuity and balance control strategy. One hypothesis refers to the existence of a threshold value of visual acuity as a turning point between the eyes-open and eyes-closed strategy. The other assumes that the change from eyes-open to eyes-closed behavior is continuous and parallels the progressive worsening of visual acuity. Ten subjects balanced on the mobile platform wearing an examination frame and a facemask occluding peripheral vision. Seven different test lenses were used in different trials to modify visual acuity, from a visus value of 10/10 to severely blurred vision. Head stabilization in space progressively worsened with the decrease in visual acuity and turned toward the eyes-closed behavior when vision was blurred. The increase in head oscillation as a function of visual acuity was best fitted by a logarithmic function. In five of the subjects, additional trials were performed without facemask, to add peripheral vision to each visual acuity level, and with black lenses to allow peripheral vision alone. Addition of peripheral vision gave a significant contribution to head stabilization. With peripheral vision alone, head stabilization was intermediate between the eyes-closed and 10/10 visus value condition. We conclude that, in order to stabilize the head in space, visual information of the environment must be definite and worsening of central vision leads to a graded modification of the 'head fixed in space' behavior. Thus, the more conservative hypothesis of two different fundamental balancing strategies is not supported. Instead, the body exhibits a continuous mode of

  2. Optical phonetics and visual perception of lexical and phrasal stress in English.

    Science.gov (United States)

    Scarborough, Rebecca; Keating, Patricia; Mattys, Sven L; Cho, Taehong; Alwan, Abeer

    2009-01-01

    In a study of optical cues to the visual perception of stress, three American English talkers spoke words that differed in lexical stress and sentences that differed in phrasal stress, while video and movements of the face were recorded. The production of stressed and unstressed syllables from these utterances was analyzed along many measures of facial movement, which were generally larger and faster in the stressed condition. In a visual perception experiment, 16 perceivers identified the location of stress in forced-choice judgments of video clips of these utterances (without audio). Phrasal stress was better perceived than lexical stress. The relation of the visual intelligibility of the prosody of these utterances to the optical characteristics of their production was analyzed to determine which cues are associated with successful visual perception. While most optical measures were correlated with perception performance, chin measures, especially Chin Opening Displacement, contributed the most to correct perception independently of the other measures. Thus, our results indicate that the information for visual stress perception is mainly associated with mouth opening movements.

  3. Visual speech influences speech perception immediately but not automatically.

    Science.gov (United States)

    Mitterer, Holger; Reinisch, Eva

    2017-02-01

    Two experiments examined the time course of the use of auditory and visual speech cues to spoken word recognition using an eye-tracking paradigm. Results of the first experiment showed that the use of visual speech cues from lipreading is reduced if concurrently presented pictures require a division of attentional resources. This reduction was evident even when listeners' eye gaze was on the speaker rather than the (static) pictures. Experiment 2 used a deictic hand gesture to foster attention to the speaker. At the same time, the visual processing load was reduced by keeping the visual display constant over a fixed number of successive trials. Under these conditions, the visual speech cues from lipreading were used. Moreover, the eye-tracking data indicated that visual information was used immediately and even earlier than auditory information. In combination, these data indicate that visual speech cues are not used automatically, but if they are used, they are used immediately.

  4. Serpentine End Matching: A Test of Visual Perception

    Science.gov (United States)

    Bruce G. Hansen; Charles J. Gatchell

    1978-01-01

    In tests of gross perception of Serpentine end matched (Sem) joints in oak and cherry display panels, there were no significant differences between the number of times the non-Sem panels were chosen and the number of these selections that could be attributed to chance. Results of separate tests of sensitivity of perception of Sem joints showed that the most conspicuous...

  5. Visual perception is dependent on visuospatial working memory and thus on the posterior parietal cortex.

    Science.gov (United States)

    Pisella, Laure

    2017-06-01

    Visual perception involves complex and active processes. We will start by explaining why visual perception is dependent on visuospatial working memory, especially the spatiotemporal integration of the perceived elements through the ocular exploration of visual scenes. Then we will present neuropsychology, transcranial magnetic stimulation and neuroimaging data yielding information on the specific role of the posterior parietal cortex of the right hemisphere in visuospatial working memory. Within the posterior parietal cortex, neuropsychology data also suggest that there might be dissociated neural substrates for deployment of attention (superior parietal lobules) and spatiotemporal integration (right inferior parietal lobule). Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  6. Visuality and reading. Psychological and perceptive dynamics of reading environments (from the printed page to the visual hypertext

    Directory of Open Access Journals (Sweden)

    Micla Petrelli

    2013-02-01

    Full Text Available This essay investigates the psychological and perceptive view of reading as a visual fact and looks at its operations in different environments: from the traditional printed page to the more recent electronic page of the e-book, with particular attention reserved to the relationship between "word" (the linguistic aspects covered by the alphabetical vision and "image" (image of the word and image with the word - visual hypertext integrated with verbal texts in e-book. In the light of the studies of the Psychology of perception, Neurophysiology and Phenomenology, the experience of reading is a function that transcends those value systems tending to oppose the categories of verbal and visual, intellect and intuition, logos and disorder. But literature shows even better the inviolability of belonging of word and image, and how the thinking in images consists in building a bridge between the visible trace and the invisible thing.

  7. Perceptions of chemistry: Why is the common perception of chemistry, the most visual of sciences, so distorted?

    Science.gov (United States)

    Habraken, Clarisse L.

    1996-09-01

    Chemistry has evolved from a science dominated by mathematics into a science highly dependent on spatial-visual intelligence. Yet the chemical content of introductory courses remains taught essentially the same as 40-50 years ago. Chemistry, today, is recognized by chemists as the molecular science. Yet, school chemistry is alienated from that perception. Thanks to the computer, young people are more comfortable with visual imaging than their instructors were at the same age. Thus the time is rife to reinvigorate chemistry education by means of the visual-spatial approach, an approach wholly in conformance with the way modern chemistry is thought about and practiced.

  8. ASSESSMENT OF VISUAL PERCEPTION OF WEB-BASED VIRTUAL ENVIRONMENTS SIMULATIONS OF AN URBAN CONTEXT.

    Directory of Open Access Journals (Sweden)

    Ayman Hassaan A. Mahmoud

    2011-03-01

    Full Text Available The existing research literature on environmental perception is a body of work mainly based on the use of static representation of environments. However, the real world is usually experienced in a dynamic experience. Virtual environments’ technologies offer the potential to produce simulated environments that create the impression that we are in spaces other than those we actually occupy. A review of literature on environmental perception revealed two components of perception: “space-based” and “object-based” perception. An experiment was conducted to investigate visual perception obtained from a direct experience of an urban landscape and from its representations in desktop virtual environments (desktop VEs. The issues investigated were: accuracy of space-based and object-based visual perception obtained from the physical environment and from desktop virtual environment. A series of tests were administered to assess the visual perception of participants who explored the urban environment following a direct experience, and X3D-VRML models. The results indicated that participants who experienced the X3D-VRML models conducted fewer errors in space-based perception tests. There was evidence that participants in X3D-VRML perceived more objects than their counterparts in the physical environment. Similarities and differences between the physical and virtual environments were discussed suggesting the potential and limitations of desktop VEs in environmental representation. An agenda for future research work is suggested.

  9. Early Visual Responses Predict Conscious Face Perception within and between Subjects during Binocular Rivalry

    DEFF Research Database (Denmark)

    Sandberg, Kristian; Bahrami, Bahador; Kanai, Ryota

    2013-01-01

    Previous studies indicate that conscious face perception may be related to neural activity in a large time window around 170–800 msec after stimulus presentation, yet in the majority of these studies changes in conscious experience are confounded with changes in physical stimulation. Using...... to predict perception better than chance. In addition, source space analyses showed that sources in the early and late visual system predicted conscious perception more accurately than frontal and parietal sites, although conscious perception could also be decoded there. Finally, the patterns of neural...

  10. The effect of two different visual presentation modalities on the narratives of mainstream grade 3 children

    Directory of Open Access Journals (Sweden)

    Daleen Klop

    2013-11-01

    Method: Twenty mainstream grade 3 children were randomly assigned to two groups and assessed with one of the visual presentation methods. Narrative performance was measured in terms of micro- and macrostructure variables. Microstructure variables included productivity (total number of words, total number of T-units, syntactic complexity (mean length of T-unit and lexical diversity measures (number of different words. Macrostructure variables included episodic structure in terms of goal-attempt-outcome (GAO sequences. Results: Both visual presentation modalities elicited narratives of similar quantity and quality in terms of the micro- and macrostructure variables that were investigated. Conclusion: Animation of picture stimuli did not elicit better narratives than static picture stimuli.

  11. Common Causes of Visual Impairment Among Sixth Grade Students in Boyer Ahmad city

    Directory of Open Access Journals (Sweden)

    Shahram Bamdad

    2017-04-01

    Full Text Available Background: In line with the implementation of primary health care, Knowing the factors causing visual impairment is very helpful among children and students among population of each district. That's why in this study, we intend to study common causes of visual impairment in sixth grade elementary students in Boyer Ahmad city and we compared the results with similar studies. Materials and Methods: 1850 of 4427 sixth grade elementary students selected by Cluster sampling method in 2016-17 and they examined by linear snellen chart in the respective schools in 6 meters distance. Abnormal individuals were referred to specialized centers of Ophthalmology to determine the cause of decreased vision and they examined completely by an ophthalmologist. Results: In the initial screening, of 1850 people examined, 168 students (9.1% known abnormal based on basic view of 0.8 and they were referred to specialized clinic for specialist examination. of these, 95 students reffered to ophthalmologist. In specialist examination, 70 students (8.3% of total examined patients were visually impaired which the most important were Refractive Errors(3.84%, Amblyopia(2.3% and Strabismus(0.19%. 38% of amblyopia was refractive errors. Of total number referred to an ophthalmologist, 26.3% of people were malingering which including 2.35% of general population.   Conclusion: Refractive errors was known as the most common cause of visual impairment and Amblyopia in the study group. As for to diagnosis simplicity and treatment of refractive errors we can dramatically reduced the prevalence of amblyopia and we also can reduce the incidence of malingering through cultural measures by the Broadcasting of Province.

  12. Auditory capture of visual motion: effects on perception and discrimination.

    Science.gov (United States)

    McCourt, Mark E; Leone, Lynnette M

    2016-09-28

    We asked whether the perceived direction of visual motion and contrast thresholds for motion discrimination are influenced by the concurrent motion of an auditory sound source. Visual motion stimuli were counterphasing Gabor patches, whose net motion energy was manipulated by adjusting the contrast of the leftward-moving and rightward-moving components. The presentation of these visual stimuli was paired with the simultaneous presentation of auditory stimuli, whose apparent motion in 3D auditory space (rightward, leftward, static, no sound) was manipulated using interaural time and intensity differences, and Doppler cues. In experiment 1, observers judged whether the Gabor visual stimulus appeared to move rightward or leftward. In experiment 2, contrast discrimination thresholds for detecting the interval containing unequal (rightward or leftward) visual motion energy were obtained under the same auditory conditions. Experiment 1 showed that the perceived direction of ambiguous visual motion is powerfully influenced by concurrent auditory motion, such that auditory motion 'captured' ambiguous visual motion. Experiment 2 showed that this interaction occurs at a sensory stage of processing as visual contrast discrimination thresholds (a criterion-free measure of sensitivity) were significantly elevated when paired with congruent auditory motion. These results suggest that auditory and visual motion signals are integrated and combined into a supramodal (audiovisual) representation of motion.

  13. Perceptions Concerning Visual Culture Dialogues of Visual Art Pre-Service Teachers

    Science.gov (United States)

    Mamur, Nuray

    2012-01-01

    The visual art which is commented by the visual art teachers to help processing of the visual culture is important. In this study it is tried to describe the effect of visual culture based on the usual aesthetic experiences to be included in the learning process art education. The action research design, which is a qualitative study, is conducted…

  14. Defining the real-world reproducibility of visual grading of left ventricular function and visual estimation of left ventricular ejection fraction: impact of image quality, experience and accreditation.

    Science.gov (United States)

    Cole, Graham D; Dhutia, Niti M; Shun-Shin, Matthew J; Willson, Keith; Harrison, James; Raphael, Claire E; Zolgharni, Massoud; Mayet, Jamil; Francis, Darrel P

    2015-10-01

    Left ventricular function can be evaluated by qualitative grading and by eyeball estimation of ejection fraction (EF). We sought to define the reproducibility of these techniques, and how they are affected by image quality, experience and accreditation. Twenty apical four-chamber echocardiographic cine loops (Online Resource 1-20) of varying image quality and left ventricular function were anonymized and presented to 35 operators. Operators were asked to provide (1) a one-phrase grading of global systolic function (2) an "eyeball" EF estimate and (3) an image quality rating on a 0-100 visual analogue scale. Each observer viewed every loop twice unknowingly, a total of 1400 viewings. When grading LV function into five categories, an operator's chance of agreement with another operator was 50% and with themself on blinded re-presentation was 68%. Blinded eyeball LVEF re-estimates by the same operator had standard deviation (SD) of difference of 7.6 EF units, with the SD across operators averaging 8.3 EF units. Image quality, defined as the average of all operators' assessments, correlated with EF estimate variability (r = -0.616, p visual grading agreement (r = 0.58, p visual grading of LV function and LVEF estimation is dependent on image quality, but individuals cannot themselves identify when poor image quality is disrupting their LV function estimate. Clinicians should not assume that patients changing in grade or in visually estimated EF have had a genuine clinical change.

  15. Correlated individual differences suggest a common mechanism underlying metacognition in visual perception and visual short-term memory.

    Science.gov (United States)

    Samaha, Jason; Postle, Bradley R

    2017-11-29

    Adaptive behaviour depends on the ability to introspect accurately about one's own performance. Whether this metacognitive ability is supported by the same mechanisms across different tasks is unclear. We investigated the relationship between metacognition of visual perception and metacognition of visual short-term memory (VSTM). Experiments 1 and 2 required subjects to estimate the perceived or remembered orientation of a grating stimulus and rate their confidence. We observed strong positive correlations between individual differences in metacognitive accuracy between the two tasks. This relationship was not accounted for by individual differences in task performance or average confidence, and was present across two different metrics of metacognition and in both experiments. A model-based analysis of data from a third experiment showed that a cross-domain correlation only emerged when both tasks shared the same task-relevant stimulus feature. That is, metacognition for perception and VSTM were correlated when both tasks required orientation judgements, but not when the perceptual task was switched to require contrast judgements. In contrast with previous results comparing perception and long-term memory, which have largely provided evidence for domain-specific metacognitive processes, the current findings suggest that metacognition of visual perception and VSTM is supported by a domain-general metacognitive architecture, but only when both domains share the same task-relevant stimulus feature. © 2017 The Author(s).

  16. Parallel and Serial Grouping of Image Elements in Visual Perception

    Science.gov (United States)

    Houtkamp, Roos; Roelfsema, Pieter R.

    2010-01-01

    The visual system groups image elements that belong to an object and segregates them from other objects and the background. Important cues for this grouping process are the Gestalt criteria, and most theories propose that these are applied in parallel across the visual scene. Here, we find that Gestalt grouping can indeed occur in parallel in some…

  17. Parallel and serial grouping of image elements in visual perception

    NARCIS (Netherlands)

    Houtkamp, R.; Roelfsema, P.R.

    2010-01-01

    The visual system groups image elements that belong to an object and segregates them from other objects and the background. Important cues for this grouping process are the Gestalt criteria, and most theories propose that these are applied in parallel across the visual scene. Here, we find that

  18. Working Memory Enhances Visual Perception: Evidence from Signal Detection Analysis

    Science.gov (United States)

    Soto, David; Wriglesworth, Alice; Bahrami-Balani, Alex; Humphreys, Glyn W.

    2010-01-01

    We show that perceptual sensitivity to visual stimuli can be modulated by matches between the contents of working memory (WM) and stimuli in the visual field. Observers were presented with an object cue (to hold in WM or to merely attend) and subsequently had to identify a brief target presented within a colored shape. The cue could be…

  19. Visual arts and the teaching of the mathematical concepts of shape and space in Grade R classrooms

    Directory of Open Access Journals (Sweden)

    Dianne Wilmot

    2015-09-01

    Full Text Available This article addresses the need for research in the areas of Grade R curriculum and pedagogy, Grade R teacher professional development, and early years mathematics teaching. More specifically, it responds to the need for teacher professional development in Grade R mathematics teaching of the geometric concepts of space and shape. The article describes a study about teachers’ understanding of how visual arts can be used as pedagogical modality. The study was prompted by the findings of a ‘Maths and Science through Arts and Culture Curriculum’ intervention undertaken with Grade R teachers enrolled for a Bachelor of Education (Foundation Phase degree at a South African university. Post-intervention, teachers’ classroom practices did not change, and they were not using visual arts to teach mathematical concepts. The lessons learned from the research intervention may contribute to the wider debate about Grade R teaching and children’s learning.

  20. Simultaneous object perception deficits are related to reduced visual processing speed in amnestic mild cognitive impairment.

    Science.gov (United States)

    Ruiz-Rizzo, Adriana L; Bublak, Peter; Redel, Petra; Grimmer, Timo; Müller, Hermann J; Sorg, Christian; Finke, Kathrin

    2017-07-01

    Simultanagnosia, an impairment in simultaneous object perception, has been attributed to deficits in visual attention and, specifically, to processing speed. Increasing visual attention deficits manifest over the course of Alzheimer's disease (AD), where the first changes are present already in its symptomatic predementia phase: amnestic mild cognitive impairment (aMCI). In this study, we examined whether patients with aMCI due to AD show simultaneous object perception deficits and whether and how these deficits relate to visual attention. Sixteen AD patients with aMCI and 16 age-, gender-, and education-matched healthy controls were assessed with a simultaneous perception task, with shapes presented in an adjacent, embedded, or overlapping manner, under free viewing without temporal constraints. We used a parametric assessment of visual attention based on the Theory of Visual Attention. Results show that patients make significantly more errors than controls when identifying overlapping shapes, which correlate with reduced processing speed. Our findings suggest simultaneous object perception deficits in very early AD, and a visual processing speed reduction underlying these deficits. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. THE ROLE OF VISUAL GRAMMAR AND PLAYER PERCEPTION IN AN ONLINE GAME

    DEFF Research Database (Denmark)

    Nobaew, Banphot

    This study investigates the relationship between the visual design and player experience in the online game. This study focuses on the role of visual grammar in relation to player perception in World of Warcraft. The phrase ‘visual grammar’ in this study is a metaphor representing to ‘the...... images, the site of player and interaction. This study carries on two main data which are the author gameplay experience and the gameplay workshop. The final results of this study are used to propose the fundamental visual grammar for analyzing three-dimensional online games. This fundamental structure...... principles and rules of a visual game landscape (the game territory and environment) for composing the forms of visual elements and structuring the meaning of perceptual experience. It creates the system of visual communication in a particular context’. This study employs two approaches which combine...

  2. Regression models for analyzing radiological visual grading studies--an empirical comparison.

    Science.gov (United States)

    Saffari, S Ehsan; Löve, Áskell; Fredrikson, Mats; Smedby, Örjan

    2015-10-30

    For optimizing and evaluating image quality in medical imaging, one can use visual grading experiments, where observers rate some aspect of image quality on an ordinal scale. To analyze the grading data, several regression methods are available, and this study aimed at empirically comparing such techniques, in particular when including random effects in the models, which is appropriate for observers and patients. Data were taken from a previous study where 6 observers graded or ranked in 40 patients the image quality of four imaging protocols, differing in radiation dose and image reconstruction method. The models tested included linear regression, the proportional odds model for ordinal logistic regression, the partial proportional odds model, the stereotype logistic regression model and rank-order logistic regression (for ranking data). In the first two models, random effects as well as fixed effects could be included; in the remaining three, only fixed effects. In general, the goodness of fit (AIC and McFadden's Pseudo R (2)) showed small differences between the models with fixed effects only. For the mixed-effects models, higher AIC and lower Pseudo R (2) was obtained, which may be related to the different number of parameters in these models. The estimated potential for dose reduction by new image reconstruction methods varied only slightly between models. The authors suggest that the most suitable approach may be to use ordinal logistic regression, which can handle ordinal data and random effects appropriately.

  3. Long-Lasting Enhancement of Visual Perception with Repetitive Noninvasive Transcranial Direct Current Stimulation

    Directory of Open Access Journals (Sweden)

    Janina R. Behrens

    2017-08-01

    Full Text Available Understanding processes performed by an intact visual cortex as the basis for developing methods that enhance or restore visual perception is of great interest to both researchers and medical practitioners. Here, we explore whether contrast sensitivity, a main function of the primary visual cortex (V1, can be improved in healthy subjects by repetitive, noninvasive anodal transcranial direct current stimulation (tDCS. Contrast perception was measured via threshold perimetry directly before and after intervention (tDCS or sham stimulation on each day over 5 consecutive days (24 subjects, double-blind study. tDCS improved contrast sensitivity from the second day onwards, with significant effects lasting 24 h. After the last stimulation on day 5, the anodal group showed a significantly greater improvement in contrast perception than the sham group (23 vs. 5%. We found significant long-term effects in only the central 2–4° of the visual field 4 weeks after the last stimulation. We suspect a combination of two factors contributes to these lasting effects. First, the V1 area that represents the central retina was located closer to the polarization electrode, resulting in higher current density. Second, the central visual field is represented by a larger cortical area relative to the peripheral visual field (cortical magnification. This is the first study showing that tDCS over V1 enhances contrast perception in healthy subjects for several weeks. This study contributes to the investigation of the causal relationship between the external modulation of neuronal membrane potential and behavior (in our case, visual perception. Because the vast majority of human studies only show temporary effects after single tDCS sessions targeting the visual system, our study underpins the potential for lasting effects of repetitive tDCS-induced modulation of neuronal excitability.

  4. Depth perception: cuttlefish (Sepia officinalis) respond to visual texture density gradients.

    Science.gov (United States)

    Josef, Noam; Mann, Ofri; Sykes, António V; Fiorito, Graziano; Reis, João; Maccusker, Steven; Shashar, Nadav

    2014-11-01

    Studies concerning the perceptual processes of animals are not only interesting, but are fundamental to the understanding of other developments in information processing among non-humans. Carefully used visual illusions have been proven to be an informative tool for understanding visual perception. In this behavioral study, we demonstrate that cuttlefish are responsive to visual cues involving texture gradients. Specifically, 12 out of 14 animals avoided swimming over a solid surface with a gradient picture that to humans resembles an illusionary crevasse, while only 5 out of 14 avoided a non-illusionary texture. Since texture gradients are well-known cues for depth perception in vertebrates, we suggest that these cephalopods were responding to the depth illusion created by the texture density gradient. Density gradients and relative densities are key features in distance perception in vertebrates. Our results suggest that they are fundamental features of vision in general, appearing also in cephalopods.

  5. Passive sensorimotor stimulation triggers long lasting alpha-band fluctuations in visual perception.

    Science.gov (United States)

    Tomassini, Alice; D'Ausilio, Alessandro

    2018-02-01

    Movement planning and execution rely on the anticipation and online control of the incoming sensory input. Evidence suggests that sensorimotor processes may synchronize visual rhythmic activity in preparation of action performance. Indeed, we recently reported periodic fluctuations of visual contrast sensitivity that are time-locked to the onset of an intended movement of the arm. However, the origin of the observed visual modulations has so far remained unclear because of the endogenous (and thus temporally undetermined) activation of the sensorimotor system that is associated with voluntary movement initiation. In this study, we activated the sensorimotor circuitry involved in the hand control in an exogenous and controlled way by means of peripheral stimulation of the median nerve and characterized the spectrotemporal dynamics of the ensuing visual perception. The stimulation of the median nerve triggers robust and long-lasting (∼1 s) alpha-band oscillations in visual perception, whose strength is temporally modulated in a way that is consistent with the changes in alpha power described at the neurophysiological level after sensorimotor stimulation. These findings provide evidence in support of a causal role of the sensorimotor system in modulating oscillatory activity in visual areas with consequences for visual perception. NEW & NOTEWORTHY This study shows that the peripheral activation of the somatomotor hand system triggers long-lasting alpha periodicity in visual perception. This demonstrates that not only the endogenous sensorimotor processes involved in movement preparation but also the passive stimulation of the sensorimotor system can synchronize visual activity. The present work suggests that oscillation-based mechanisms may subserve core (task independent) sensorimotor integration functions.

  6. Effects of Auditory Information on Self-Motion Perception during Simultaneous Presentation of Visual Shearing Motion

    Directory of Open Access Journals (Sweden)

    Shigehito eTanahashi

    2015-06-01

    Full Text Available Recent studies have found that self-motion perception induced by simultaneous presentation of visual and auditory motion is facilitated when the directions of visual and auditory motion stimuli are identical. They did not, however, examine possible contributions of auditory motion information for determining direction of self-motion perception. To examine this, a visual stimulus projected on a hemisphere screen and an auditory stimulus presented through headphones were presented separately or simultaneously, depending on experimental conditions. The participant continuously indicated the direction and strength of self-motion during the 130-s experimental trial. When the visual stimulus with a horizontal shearing rotation and the auditory stimulus with a horizontal one-directional rotation were presented simultaneously, the duration and strength of self-motion perceived in the opposite direction of the auditory rotation stimulus were significantly longer and stronger than those perceived in the same direction of the auditory rotation stimulus. However, the auditory stimulus alone could not sufficiently induce self-motion perception, and if it did, its direction was not consistent within each experimental trial. We concluded that auditory motion information can determine perceived direction of self-motion during simultaneous presentation of visual and auditory motion information, at least when visual stimuli moved in opposing directions (around the yaw-axis. We speculate that the contribution of auditory information depends on the plausibility and information balance of visual and auditory information.

  7. Tactile force perception depends on the visual speed of the collision object.

    Science.gov (United States)

    Arai, Kan; Okajima, Katsunori

    2009-10-22

    Previous research on the interaction between vision and touch has employed static visual and continuous tactile stimuli, and has shown that two kinds of multimodal interaction effect exist: the averaging effect and the contrast effect. The averaging effect has been used to explain several kinds of stimuli interaction while the contrast effect is associated only with the size-weight illusion (A. Charpentier, 1891). Here, we describe a novel visuotactile interaction using visual motion information that can be explained with the contrast effect. We show that the magnitude of tactile force perception (MTFP) from an impact on the palm is significantly modified by the visual motion information of a virtual collision event. Our collision simulator generates visual stimuli independently from the corresponding tactile stimuli. The results show that visual speed modified MTFP even though the actual contact force remained constant: higher visual pre- and post-collision speeds induced lower tactile force perception. Finally, we propose a quantitative model of MTFP in which MTFP is expressed as a function of the visual velocity difference, suggesting that the gain of the tactile perception in the human brain is altered via MTFP modulation.

  8. Effects of auditory information on self-motion perception during simultaneous presentation of visual shearing motion

    Science.gov (United States)

    Tanahashi, Shigehito; Ashihara, Kaoru; Ujike, Hiroyasu

    2015-01-01

    Recent studies have found that self-motion perception induced by simultaneous presentation of visual and auditory motion is facilitated when the directions of visual and auditory motion stimuli are identical. They did not, however, examine possible contributions of auditory motion information for determining direction of self-motion perception. To examine this, a visual stimulus projected on a hemisphere screen and an auditory stimulus presented through headphones were presented separately or simultaneously, depending on experimental conditions. The participant continuously indicated the direction and strength of self-motion during the 130-s experimental trial. When the visual stimulus with a horizontal shearing rotation and the auditory stimulus with a horizontal one-directional rotation were presented simultaneously, the duration and strength of self-motion perceived in the opposite direction of the auditory rotation stimulus were significantly longer and stronger than those perceived in the same direction of the auditory rotation stimulus. However, the auditory stimulus alone could not sufficiently induce self-motion perception, and if it did, its direction was not consistent within each experimental trial. We concluded that auditory motion information can determine perceived direction of self-motion during simultaneous presentation of visual and auditory motion information, at least when visual stimuli moved in opposing directions (around the yaw-axis). We speculate that the contribution of auditory information depends on the plausibility and information balance of visual and auditory information. PMID:26113828

  9. THE USE OF VISUAL CARD MEDIA IN TEACHING LEARNING GRAMMAR AT THE SECOND GRADE OF MADRASAH ALIYAH NEGERI (MAN PAMEKASAN

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    Mohammad Muchlis Solichin

    2017-12-01

    Full Text Available This research wants to know 1 How does the teacher implement visual card media on students grammar at the second grade of MAN Pamekasan? 2. What are the problems faced by the students in teaching grammar by using visual card media on students grammar at the second grade of MAN Pamekasan 3. How does the student’s response to the implementation of visual card media on students’ grammar at the second grade of MAN Pamekasan. The researcher uses the qualitative approach, that has become because it provides valuable insights into the local perspectives of study population, and chooses to use non- participant observation,  The finding of the research are: 1 The implementation of visual card media in teaching grammar at the second grade of MAN Pamekasan is very good. It makes students active in the class and enjoys in the learning process. 2 the student’s problems in the implementation of visual card media in teaching grammar at the second grade of MAN Pamekasan are the preparation of students, less comprehension, self-confidence. 3. The student’s give the positive response.

  10. Augmentation of ’Visual Perception of Elevation’

    Science.gov (United States)

    1998-01-26

    Hertzman, Machover , Meissner, and Wapner, 1954; Witkin et. al., 1971), such as that shown in Figure 4. The purpose of the present study was to...Personality, 19, 1-15. Witkin, H.A., Lewis, H. B., Hertzman, M., Machover , K., Meissner,P., & Wapner, S. (1954) Personality through perception. New York

  11. Language and visual perception associations: meta-analytic connectivity modeling of Brodmann area 37.

    Science.gov (United States)

    Ardila, Alfredo; Bernal, Byron; Rosselli, Monica

    2015-01-01

    Understanding the functions of different brain areas has represented a major endeavor of neurosciences. Historically, brain functions have been associated with specific cortical brain areas; however, modern neuroimaging developments suggest cognitive functions are associated to networks rather than to areas. The purpose of this paper was to analyze the connectivity of Brodmann area (BA) 37 (posterior, inferior, and temporal/fusiform gyrus) in relation to (1) language and (2) visual processing. Two meta-analyses were initially conducted (first level analysis). The first one was intended to assess the language network in which BA37 is involved. The second one was intended to assess the visual perception network. A third meta-analysis (second level analysis) was then performed to assess contrasts and convergence between the two cognitive domains (language and visual perception). The DataBase of Brainmap was used. Our results support the role of BA37 in language but by means of a distinct network from the network that supports its second most important function: visual perception. It was concluded that left BA37 is a common node of two distinct networks-visual recognition (perception) and semantic language functions.

  12. Language and Visual Perception Associations: Meta-Analytic Connectivity Modeling of Brodmann Area 37

    Directory of Open Access Journals (Sweden)

    Alfredo Ardila

    2015-01-01

    Full Text Available Background. Understanding the functions of different brain areas has represented a major endeavor of neurosciences. Historically, brain functions have been associated with specific cortical brain areas; however, modern neuroimaging developments suggest cognitive functions are associated to networks rather than to areas. Objectives. The purpose of this paper was to analyze the connectivity of Brodmann area (BA 37 (posterior, inferior, and temporal/fusiform gyrus in relation to (1 language and (2 visual processing. Methods. Two meta-analyses were initially conducted (first level analysis. The first one was intended to assess the language network in which BA37 is involved. The second one was intended to assess the visual perception network. A third meta-analysis (second level analysis was then performed to assess contrasts and convergence between the two cognitive domains (language and visual perception. The DataBase of Brainmap was used. Results. Our results support the role of BA37 in language but by means of a distinct network from the network that supports its second most important function: visual perception. Conclusion. It was concluded that left BA37 is a common node of two distinct networks—visual recognition (perception and semantic language functions.

  13. Human cortical neural correlates of visual fatigue during binocular depth perception: An fNIRS study.

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    Tingting Cai

    Full Text Available Functional near-infrared spectroscopy (fNIRS was adopted to investigate the cortical neural correlates of visual fatigue during binocular depth perception for different disparities (from 0.1° to 1.5°. By using a slow event-related paradigm, the oxyhaemoglobin (HbO responses to fused binocular stimuli presented by the random-dot stereogram (RDS were recorded over the whole visual dorsal area. To extract from an HbO curve the characteristics that are correlated with subjective experiences of stereopsis and visual fatigue, we proposed a novel method to fit the time-course HbO curve with various response functions which could reflect various processes of binocular depth perception. Our results indicate that the parietal-occipital cortices are spatially correlated with binocular depth perception and that the process of depth perception includes two steps, associated with generating and sustaining stereovision. Visual fatigue is caused mainly by generating stereovision, while the amplitude of the haemodynamic response corresponding to sustaining stereovision is correlated with stereopsis. Combining statistical parameter analysis and the fitted time-course analysis, fNIRS could be a promising method to study visual fatigue and possibly other multi-process neural bases.

  14. Visual perception in preterm children: what are we currently measuring?

    Science.gov (United States)

    Ortibus, Els L; De Cock, Paul P; Lagae, Lieven G

    2011-07-01

    Over the past two decades, cerebral visual impairment has been recognized as a principal deficit in preterm children, and in particular those with cerebral palsy. We review the current knowledge of visual processing deficits in these children, and provide an overview of the tools for assessing cerebral visual impairment. Commercially available instruments are usually directed at evaluating visuospatial skills rather than detecting object recognition difficulties. Particularly in children aged 3 years or younger and in children with multiple handicaps, cerebral visual impairment is difficult to diagnose. This difficulty may be attributable to limitations specific to the instrument, such as a test that is inappropriate for age, or to child-specific limitations such as motor impairment or speech delay. We therefore include an overview of relevant neuroimaging findings reported in these children, focusing on the most recent imaging modalities. Novel techniques such as diffusion tensor imaging may provide sensitive markers of cerebral visual impairment in situations where clinical diagnosis is difficult, and such approaches may allow for early intervention. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Components of Appearance in the Structure of Perception of Visual Representations of Age

    OpenAIRE

    Shkurko T.A.; Nikolaeva E.G.

    2015-01-01

    The article discusses the problem of perception of age (one’s own and that of other people), which is regarded as a special case of social perception. The aim of this study was to analyze the components of another person’s appearance in the structure of perception of visual representations of age. For these purposes the authors created a special technique, “Identifying Age through Photo Visualization” (Shkurko T.A., Nikolaeva E. G.). The study enrolled 20 individuals (10 men, 10 women aged 18...

  16. What can fish brains tell us about visual perception?

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    Orsola eRosa Salva

    2014-09-01

    Full Text Available Fish are a complex taxonomic group, whose diversity and distance from other vertebrates well suits the comparative investigation of brain and behavior: in fish species we observe substantial differences with respect to the telencephalic organization of other vertebrates and an astonishing variety in the development and complexity of pallial structures. We will concentrate on the contribution of research on fish behavioral biology for the understanding of the evolution of the visual system. We shall review evidence concerning perceptual effects that reflect fundamental principles of the visual system functioning, highlighting the similarities and differences between distant fish groups and with other vertebrates. We will focus on perceptual effects reflecting some of the main tasks that the visual system must attain. In particular, we will deal with subjective contours and optical illusions, invariance effects, second order motion and biological motion and, finally, perceptual binding of object properties in a unified higher level representation.

  17. Biases in Visual, Auditory, and Audiovisual Perception of Space

    Science.gov (United States)

    Odegaard, Brian; Wozny, David R.; Shams, Ladan

    2015-01-01

    Localization of objects and events in the environment is critical for survival, as many perceptual and motor tasks rely on estimation of spatial location. Therefore, it seems reasonable to assume that spatial localizations should generally be accurate. Curiously, some previous studies have reported biases in visual and auditory localizations, but these studies have used small sample sizes and the results have been mixed. Therefore, it is not clear (1) if the reported biases in localization responses are real (or due to outliers, sampling bias, or other factors), and (2) whether these putative biases reflect a bias in sensory representations of space or a priori expectations (which may be due to the experimental setup, instructions, or distribution of stimuli). Here, to address these questions, a dataset of unprecedented size (obtained from 384 observers) was analyzed to examine presence, direction, and magnitude of sensory biases, and quantitative computational modeling was used to probe the underlying mechanism(s) driving these effects. Data revealed that, on average, observers were biased towards the center when localizing visual stimuli, and biased towards the periphery when localizing auditory stimuli. Moreover, quantitative analysis using a Bayesian Causal Inference framework suggests that while pre-existing spatial biases for central locations exert some influence, biases in the sensory representations of both visual and auditory space are necessary to fully explain the behavioral data. How are these opposing visual and auditory biases reconciled in conditions in which both auditory and visual stimuli are produced by a single event? Potentially, the bias in one modality could dominate, or the biases could interact/cancel out. The data revealed that when integration occurred in these conditions, the visual bias dominated, but the magnitude of this bias was reduced compared to unisensory conditions. Therefore, multisensory integration not only improves the

  18. Genre Differences on Visual Perception of Color Range and Depth of Field

    Directory of Open Access Journals (Sweden)

    Luisa Ballesteros

    2003-07-01

    Full Text Available Visual perception is the result of the integration of various related factors of the observed object and its environment. In this study we evaluated the impact of tridimensional form on color perception and the angle from the horizontal plane of a set of similar objets on the depth of field perception between young men and women. A panel half magenta and half white placed at the end of a black box, folded either concaved or convexed to alter the chromatic effect perceived were used to determine tridimensional form on color perception. Four sets of identical sticks where the angle from the horizontal plane varied for each, were used to determine the effect of spatial distribution of depth of field perception. The parameters taking into account were age, genre, associated visual defects for each individual evaluated. Our results show that the tridimensional form alters color perception but the range of color perceived was larger for women whereas depending on the angle from the horizontal plane we found genre differences on the depth of field perception.

  19. Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia

    Science.gov (United States)

    Zoubrinetzky, Rachel; Collet, Gregory; Serniclaes, Willy; Nguyen-Morel, Marie-Ange; Valdois, Sylviane

    2016-01-01

    We tested the hypothesis that the categorical perception deficit of speech sounds in developmental dyslexia is related to phoneme awareness skills, whereas a visual attention (VA) span deficit constitutes an independent deficit. Phoneme awareness tasks, VA span tasks and categorical perception tasks of phoneme identification and discrimination using a d/t voicing continuum were administered to 63 dyslexic children and 63 control children matched on chronological age. Results showed significant differences in categorical perception between the dyslexic and control children. Significant correlations were found between categorical perception skills, phoneme awareness and reading. Although VA span correlated with reading, no significant correlations were found between either categorical perception or phoneme awareness and VA span. Mediation analyses performed on the whole dyslexic sample suggested that the effect of categorical perception on reading might be mediated by phoneme awareness. This relationship was independent of the participants’ VA span abilities. Two groups of dyslexic children with a single phoneme awareness or a single VA span deficit were then identified. The phonologically impaired group showed lower categorical perception skills than the control group but categorical perception was similar in the VA span impaired dyslexic and control children. The overall findings suggest that the link between categorical perception, phoneme awareness and reading is independent from VA span skills. These findings provide new insights on the heterogeneity of developmental dyslexia. They suggest that phonological processes and VA span independently affect reading acquisition. PMID:26950210

  20. Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia.

    Science.gov (United States)

    Zoubrinetzky, Rachel; Collet, Gregory; Serniclaes, Willy; Nguyen-Morel, Marie-Ange; Valdois, Sylviane

    2016-01-01

    We tested the hypothesis that the categorical perception deficit of speech sounds in developmental dyslexia is related to phoneme awareness skills, whereas a visual attention (VA) span deficit constitutes an independent deficit. Phoneme awareness tasks, VA span tasks and categorical perception tasks of phoneme identification and discrimination using a d/t voicing continuum were administered to 63 dyslexic children and 63 control children matched on chronological age. Results showed significant differences in categorical perception between the dyslexic and control children. Significant correlations were found between categorical perception skills, phoneme awareness and reading. Although VA span correlated with reading, no significant correlations were found between either categorical perception or phoneme awareness and VA span. Mediation analyses performed on the whole dyslexic sample suggested that the effect of categorical perception on reading might be mediated by phoneme awareness. This relationship was independent of the participants' VA span abilities. Two groups of dyslexic children with a single phoneme awareness or a single VA span deficit were then identified. The phonologically impaired group showed lower categorical perception skills than the control group but categorical perception was similar in the VA span impaired dyslexic and control children. The overall findings suggest that the link between categorical perception, phoneme awareness and reading is independent from VA span skills. These findings provide new insights on the heterogeneity of developmental dyslexia. They suggest that phonological processes and VA span independently affect reading acquisition.

  1. Backtracking Method of Coloring Administrative Maps Considering Visual Perception Rules

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    WEI Zhiwei

    2018-03-01

    Full Text Available Color design in administrative maps should incorporate and balance area configuration, color harmony, and users' purposes. Based on visual perceptual rules, this paper quantifies color harmony, color contrast and perceptual balance in coloring administrative maps, and a model is suggested to evaluate the coloring quality after color template is selected. Then a backtracking method based on area balance is proposed to compute colored areas. Experiments show that this method can well meet visual perceptual rules while coloring administrative maps, and can be used for later map design.

  2. Audiovisual associations alter the perception of low-level visual motion

    Directory of Open Access Journals (Sweden)

    Hulusi eKafaligonul

    2015-03-01

    Full Text Available Motion perception is a pervasive nature of vision and is affected by both immediate pattern of sensory inputs and prior experiences acquired through associations. Recently, several studies reported that an association can be established quickly between directions of visual motion and static sounds of distinct frequencies. After the association is formed, sounds are able to change the perceived direction of visual motion. To determine whether such rapidly acquired audiovisual associations and their subsequent influences on visual motion perception are dependent on the involvement of higher-order attentive tracking mechanisms, we designed psychophysical experiments using regular and reverse-phi random dot motions isolating low-level pre-attentive motion processing. Our results show that an association between the directions of low-level visual motion and static sounds can be formed and this audiovisual association alters the subsequent perception of low-level visual motion. These findings support the view that audiovisual associations are not restricted to high-level attention based motion system and early-level visual motion processing has some potential role.

  3. Person perception informs understanding of cognition during visual search.

    Science.gov (United States)

    Brennan, Allison A; Watson, Marcus R; Kingstone, Alan; Enns, James T

    2011-08-01

    Does person perception--the impressions we form from watching others--hold clues to the mental states of people engaged in cognitive tasks? We investigated this with a two-phase method: In Phase 1, participants searched on a computer screen (Experiment 1) or in an office (Experiment 2); in Phase 2, other participants rated the searchers' video-recorded behavior. The results showed that blind raters are sensitive to individual differences in search proficiency and search strategy, as well as to environmental factors affecting search difficulty. Also, different behaviors were linked to search success in each setting: Eye movement frequency predicted successful search on a computer screen; head movement frequency predicted search success in an office. In both settings, an active search strategy and positive emotional expressions were linked to search success. These data indicate that person perception informs cognition beyond the scope of performance measures, offering the potential for new measurements of cognition that are both rich and unobtrusive.

  4. High grade CIN diagnosis by combined visual inspection with Lugol's iodine and cytology in symptomatic women.

    Science.gov (United States)

    Russo, Evandro; Kupek, Emil; Zanine, Rita Maria

    2011-05-01

    To investigate the diagnostic performance of combining the visual inspection with Lugol's iodine (VILI) and cytology screening to detect high-grade cervical intraepithelial neoplasia (CIN-2 or CIN-3) in symptomatic women, using histological examination as the standard reference test. Cross-sectional referral study utilizing secondary data from 538 medical records from a clinic specialized in cervical pathology in Brazil. Although the sensitivity reached 96.8%, the specificity was only 8.1%, with positive predictive value of 18.3% and negative predictive value of 92.3%. The combination of both tests proved to be highly sensitive, leading to a large decrease in the false negative results. This was achieved, however, at the cost of an excess in the rate of false positive results, thus making the combination unviable for screening in symptomatic women. Crown Copyright © 2011. Published by Elsevier Ireland Ltd. All rights reserved.

  5. Audio-Visual Perception System for a Humanoid Robotic Head

    Science.gov (United States)

    Viciana-Abad, Raquel; Marfil, Rebeca; Perez-Lorenzo, Jose M.; Bandera, Juan P.; Romero-Garces, Adrian; Reche-Lopez, Pedro

    2014-01-01

    One of the main issues within the field of social robotics is to endow robots with the ability to direct attention to people with whom they are interacting. Different approaches follow bio-inspired mechanisms, merging audio and visual cues to localize a person using multiple sensors. However, most of these fusion mechanisms have been used in fixed systems, such as those used in video-conference rooms, and thus, they may incur difficulties when constrained to the sensors with which a robot can be equipped. Besides, within the scope of interactive autonomous robots, there is a lack in terms of evaluating the benefits of audio-visual attention mechanisms, compared to only audio or visual approaches, in real scenarios. Most of the tests conducted have been within controlled environments, at short distances and/or with off-line performance measurements. With the goal of demonstrating the benefit of fusing sensory information with a Bayes inference for interactive robotics, this paper presents a system for localizing a person by processing visual and audio data. Moreover, the performance of this system is evaluated and compared via considering the technical limitations of unimodal systems. The experiments show the promise of the proposed approach for the proactive detection and tracking of speakers in a human-robot interactive framework. PMID:24878593

  6. [The eye and the perception of reality through visual arts].

    Science.gov (United States)

    Romano, Hugues

    2011-01-01

    Artists' view on the world and the way they convey it in their work provide avenues towards understanding the evolution of our societies, as well as the status of scientific knowledge. Reflection of an ophthalmologist and painter who has explored view and gaze through the production of visual arts.

  7. The Use of Illusory Visual Information in Perception and Action

    NARCIS (Netherlands)

    D.D.J. de Grave (Denise)

    2005-01-01

    markdownabstract__Abstract__ Humans constantly interact with objects in the environment (e.g. grasp a pencil for writing or pick up a cup of tea) without making many mistakes in these performed actions. To guide these actions, visual information is used. In order to accurately grasp and pick up

  8. NMDA receptor antagonist ketamine impairs feature integration in visual perception

    NARCIS (Netherlands)

    Meuwese, Julia D. I.; van Loon, Anouk M.; Scholte, H. Steven; Lirk, Philipp B.; Vulink, Nienke C. C.; Hollmann, Markus W.; Lamme, Victor A. F.

    2013-01-01

    Recurrent interactions between neurons in the visual cortex are crucial for the integration of image elements into coherent objects, such as in figure-ground segregation of textured images. Blocking N-methyl-D-aspartate (NMDA) receptors in monkeys can abolish neural signals related to figure-ground

  9. Audio-Visual Speech in Noise Perception in Dyslexia

    Science.gov (United States)

    van Laarhoven, Thijs; Keetels, Mirjam; Schakel, Lemmy; Vroomen, Jean

    2018-01-01

    Individuals with developmental dyslexia (DD) may experience, besides reading problems, other speech-related processing deficits. Here, we examined the influence of visual articulatory information (lip-read speech) at various levels of background noise on auditory word recognition in children and adults with DD. We found that children with a…

  10. Exploratory Visual Analysis of Statistical Results from Microarray Experiments Comparing High and Low Grade Glioma

    Directory of Open Access Journals (Sweden)

    Jason H. Moore

    2007-01-01

    Full Text Available The biological interpretation of gene expression microarray results is a daunting challenge. For complex diseases such as cancer, wherein the body of published research is extensive, the incorporation of expert knowledge provides a useful analytical framework. We have previously developed the Exploratory Visual Analysis (EVA software for exploring data analysis results in the context of annotation information about each gene, as well as biologically relevant groups of genes. We present EVA as a fl exible combination of statistics and biological annotation that provides a straightforward visual interface for the interpretation of microarray analyses of gene expression in the most commonly occurring class of brain tumors, glioma. We demonstrate the utility of EVA for the biological interpretation of statistical results by analyzing publicly available gene expression profi les of two important glial tumors. The results of a statistical comparison between 21 malignant, high-grade glioblastoma multiforme (GBM tumors and 19 indolent, low-grade pilocytic astrocytomas were analyzed using EVA. By using EVA to examine the results of a relatively simple statistical analysis, we were able to identify tumor class-specifi c gene expression patterns having both statistical and biological signifi cance. Our interactive analysis highlighted the potential importance of genes involved in cell cycle progression, proliferation, signaling, adhesion, migration, motility, and structure, as well as candidate gene loci on a region of Chromosome 7 that has been implicated in glioma. Because EVA does not require statistical or computational expertise and has the fl exibility to accommodate any type of statistical analysis, we anticipate EVA will prove a useful addition to the repertoire of computational methods used for microarray data analysis. EVA is available at no charge to academic users and can be found at http://www.epistasis.org.

  11. Teachers’ Perceptions Regarding the Curriculum Of an 8th Grade English Course Based on the CIPP Model

    OpenAIRE

    Batdı, V.

    2015-01-01

    The purpose of this research is to investigate teachers’ perceptions regarding the curriculum of an 8th grade English course, taught within secondary schools in the 2013 to 2014 academic year, and to analyse these perceptions with Stufflebeam’s context, input, process and product (CIPP) model. As a descriptive survey model, the sampling consisted of 103 English teachers worked in secondary schools in Elazığ and selected randomly from the population. The teacher form of the scale, which was de...

  12. A Qualitative Examination of the Perceptions of the Eight Grade Students Regarding the Concept of Environmental Pollution

    OpenAIRE

    , B Kilcan; , O Çepni

    2016-01-01

    The purpose of this study was to determine the perceptions of the eight grade students regarding the concept of “environmental pollution” covered in the 6th and 7th grades' social studies curriculum. To this end, the metaphors produced by the students in regard to this concept and the pictures/cartoons drawn by them about it were examined. This qualitative study conducted survey model. Qualitative research techniques considered suitable for triangulation (collecting data via metaphors an...

  13. Toward unsupervised outbreak detection through visual perception of new patterns

    Directory of Open Access Journals (Sweden)

    Lévy Pierre P

    2009-06-01

    Full Text Available Abstract Background Statistical algorithms are routinely used to detect outbreaks of well-defined syndromes, such as influenza-like illness. These methods cannot be applied to the detection of emerging diseases for which no preexisting information is available. This paper presents a method aimed at facilitating the detection of outbreaks, when there is no a priori knowledge of the clinical presentation of cases. Methods The method uses a visual representation of the symptoms and diseases coded during a patient consultation according to the International Classification of Primary Care 2nd version (ICPC-2. The surveillance data are transformed into color-coded cells, ranging from white to red, reflecting the increasing frequency of observed signs. They are placed in a graphic reference frame mimicking body anatomy. Simple visual observation of color-change patterns over time, concerning a single code or a combination of codes, enables detection in the setting of interest. Results The method is demonstrated through retrospective analyses of two data sets: description of the patients referred to the hospital by their general practitioners (GPs participating in the French Sentinel Network and description of patients directly consulting at a hospital emergency department (HED. Informative image color-change alert patterns emerged in both cases: the health consequences of the August 2003 heat wave were visualized with GPs' data (but passed unnoticed with conventional surveillance systems, and the flu epidemics, which are routinely detected by standard statistical techniques, were recognized visually with HED data. Conclusion Using human visual pattern-recognition capacities to detect the onset of unexpected health events implies a convenient image representation of epidemiological surveillance and well-trained "epidemiology watchers". Once these two conditions are met, one could imagine that the epidemiology watchers could signal epidemiological alerts

  14. Developmental visual perception deficits with no indications of prosopagnosia in a child with abnormal eye movements.

    Science.gov (United States)

    Gilaie-Dotan, Sharon; Doron, Ravid

    2017-06-01

    Visual categories are associated with eccentricity biases in high-order visual cortex: Faces and reading with foveally-biased regions, while common objects and space with mid- and peripherally-biased regions. As face perception and reading are among the most challenging human visual skills, and are often regarded as the peak achievements of a distributed neural network supporting common objects perception, it is unclear why objects, which also rely on foveal vision to be processed, are associated with mid-peripheral rather than with a foveal bias. Here, we studied BN, a 9 y.o. boy who has normal basic-level vision, abnormal (limited) oculomotor pursuit and saccades, and shows developmental object and contour integration deficits but with no indication of prosopagnosia. Although we cannot infer causation from the data presented here, we suggest that normal pursuit and saccades could be critical for the development of contour integration and object perception. While faces and perhaps reading, when fixated upon, take up a small portion of central visual field and require only small eye movements to be properly processed, common objects typically prevail in mid-peripheral visual field and rely on longer-distance voluntary eye movements as saccades to be brought to fixation. While retinal information feeds into early visual cortex in an eccentricity orderly manner, we hypothesize that propagation of non-foveal information to mid and high-order visual cortex critically relies on circuitry involving eye movements. Limited or atypical eye movements, as in the case of BN, may hinder normal information flow to mid-eccentricity biased high-order visual cortex, adversely affecting its development and consequently inducing visual perceptual deficits predominantly for categories associated with these regions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Visual Perception and Frontal Lobe in Intellectual Disabilities: A Study with Evoked Potentials and Neuropsychology

    Science.gov (United States)

    Munoz-Ruata, J.; Caro-Martinez, E.; Perez, L. Martinez; Borja, M.

    2010-01-01

    Background: Perception disorders are frequently observed in persons with intellectual disability (ID) and their influence on cognition has been discussed. The objective of this study is to clarify the mechanisms behind these alterations by analysing the visual event related potentials early component, the N1 wave, which is related to perception…

  16. An investigation into discharge, visual perception, and appearance concerns of prosthetic eye wearers.

    Science.gov (United States)

    Pine, Nicola S; de Terte, Ian; Pine, Keith R

    2017-12-01

    We investigate prosthetic eye wearers' initial and current concerns about mucoid discharge, visual perception, and appearance, and the reasons for their concerns. A retrospective, cross-sectional study of private practice patients was designed. Participants were 217 experienced prosthetic eye wearers, aged at least 16 years. An anonymous questionnaire was e-mailed or mailed to participants. Descriptive and inferential statistics were used to investigate differences or correlations between variables. Content analysis was used to analyze participants' open responses. Participants were equally concerned about discharge, visual perception, and appearance during the first three months following eye loss and at least 2 years later, even though their concerns decreased. Older participants were less concerned about appearance, while females were more concerned about current discharge and appearance. The greater the frequency and volume of discharge, the greater was the concern. Participants' initial discharge concern was due to a negative interpretation of what it meant, but later, it was due to discomfort from wiping, and how discharge looked to others. Loss of depth perception and reduced visual range were equally concerning. Initial appearance concerns related to disguisability of the prosthesis, but over time, changes to the socket and eyelids became more important. Loss of self-image is commonly considered to be the major concern of anophthalmic patients, but discharge and visual perception concerns are of equal importance. Reasons given for these concerns provide greater insight into patients' personal experience of eye loss.

  17. The modelling of avian visual perception predicts behavioural rejection responses to foreign egg colours

    Czech Academy of Sciences Publication Activity Database

    Cassey, P.; Honza, Marcel; Grim, T.; Hauber, M. E.

    2008-01-01

    Roč. 4, č. 5 (2008), s. 515-517 ISSN 1744-9561 Institutional research plan: CEZ:AV0Z60930519 Keywords : brood parasitism * egg rejection * eggshell colour * visual perception * birds Subject RIV: EG - Zoology Impact factor: 3.000, year: 2008

  18. Visual Images of Subjective Perception of Time in a Literary Text

    Science.gov (United States)

    Nesterik, Ella V.; Issina, Gaukhar I.; Pecherskikh, Taliya F.; Belikova, Oxana V.

    2016-01-01

    The article is devoted to the subjective perception of time, or psychological time, as a text category and a literary image. It focuses on the visual images that are characteristic of different types of literary time--accelerated, decelerated and frozen (vanished). The research is based on the assumption that the category of subjective perception…

  19. Parents' Perceptions of Professional Support for the Emergent Literacy of Young Children with Visual Impairments

    Science.gov (United States)

    Brennan, Susan A.; Luze, Gayle J.; Peterson, Carla

    2009-01-01

    This survey explored the emergent literacy experiences that parents provided for their children with visual impairments, aged 1-8, as well as the parents' perceptions of the professional support that they received to facilitate these activities. The results indicated that the parents and children engaged in reading, singing songs, and writing or…

  20. Studying novice and experienced teachers’ visual perception and interpretations of classroom situations

    NARCIS (Netherlands)

    Wolff, Charlotte; Van den Bogert, Niek; Van Bruggen, Jan; Jarodzka, Halszka; Jochems, Wim; Boshuizen, Els

    2013-01-01

    Wolff, C., Van den Bogert, N., Van Bruggen, J., Jochems, W. M. G., Jarodzka, H., & Boshuizen, H. P. A. (2012, October). Studying novice and experienced teachers’ visual perception and interpretations of classroom situations. Poster presented at Open Universiteit Research Day, Heerlen, The

  1. Perceptions and Concerns about Inclusive Education among Students with Visual Impairments in Lagos, Nigeria

    Science.gov (United States)

    Brydges, Colton; Mkandawire, Paul

    2017-01-01

    This article examines the perceptions of inclusive education in Lagos, Nigeria, based upon in-depth interviews conducted with students with visual impairments during the month of July 2013. The results and discussions are situated within critical disability theory. Despite decades of inclusive education policies, the findings of the study show…

  2. On the visual system's architecture underlying binocular rivalry and motion perception

    NARCIS (Netherlands)

    Boxtel, J.J.A. van

    2008-01-01

    Our everyday visual perception is supported by a complicated set of interactions between different brain areas. These areas often have a specific function. A lot of communication takes place between, and also within, these areas. The total set of interactions between and within the different brain

  3. 7th to 9th grade obese adolescents' perceptions about obesity in Tamaulipas, Mexico.

    Science.gov (United States)

    de la Luz Martínez-Aguilar, Ma; Flores-Peña, Yolanda; de las Mercedes Rizo-Baeza, Ma; Aguilar-Hernández, Rosa Ma; Vázquez-Galindo, Laura; Gutiérres-Sánchez, Gustavo

    2010-01-01

    The objective was to explore obese adolescents perceptions about obesity among students in the seventh to ninth grade of a public school in Tamaulipas, Mexico. This is a qualitative study. Participants were 24 adolescents with a body mass index equal to or greater than the 95th percentile. Semistructured interviews were conducted until data saturation was reached and the meaning was understood. The adolescents defined obesity according to standards of measurement. They identified the hereditary factor as the main obesity cause, tended to underestimate obesity and had low self-esteem. They reported problems to do physical exercise and get clothes in order to improve their image, and feel rejected by their peers in school. It was identified that these adolescents have psychological defense mechanisms against obesity and that some of them are making efforts to lose weight. Obesity entails social and psychological health implications for persons suffering from this problem. Interventions should be put in practice.

  4. Temporal sensitivity. [time dependent human perception of visual stimuli

    Science.gov (United States)

    Watson, Andrew B.

    1986-01-01

    Human visual temporal sensitivity is examined. The stimuli used to measure temporal sensitivity are described and the linear systems theory is reviewed in terms of temporal sensitivity. A working model which represents temporal sensitivity is proposed. The visibility of a number of temporal wave forms, sinusoids, rectangular pulses, and pulse pairs, is analyzed. The relation between spatial and temporal effects is studied. Temporal variations induced by image motion and the effects of light adaptation on temporal sensitivity are considered.

  5. DYNAMICS OF THE COMPELEX FORMS OF VISUAL PERCEPTION IN CHILDREN OF PRE-SCHOOL AGE (A NEUROPSYCHOLOGICAL ANALYSIS)

    OpenAIRE

    VASILEVA Neli

    2015-01-01

    Introduction: Experimental data in preschool aged children proves the determining role of the auditory and visual processes for future reading skills, therefore the investigation of complex forms of visual perception in this age period is diagnostically important. Objectives: Basic aim of the research is assessment of the sensitive period for the non-verbal perceptive operations in pre-school aged children, and determination of subgroup with low results for non-verbal perception. Method...

  6. Medical and pharmacy students' perceptions of the grading and assessment practices.

    Science.gov (United States)

    Kasanda, C D; Mitonga, K H; Veii, K; Zimba, R F

    2013-01-01

    Many students at the University of Namibia have frequently complained about ineffective assessment practices used at the institution. On many occasions, these complaints have not been substantiated with evidence of any kind. The purpose of this study was to obtain some empirical evidence that would ascertain undergraduate students' perceptions of the University of Namibia's grading and assessment practices. Using a structured scaled questionnaire, data were obtained from a representative sample of the University's undergraduate students studying for Medical and Pharmacy degrees. The questionnaire items covered matters related to students' experiences of assessment practices, feedback on assessment tasks, reliability and validity of assessment tools used by lecturers, efficacy of processes of administering examinations, perceptions of irregular and unfair assessment practices, impact of assessment regimes on students' cost of studies, motivation, morale, rate of progression in studies and graduation, the degree of compliance with assessment ethics and on academic quality assurance. According to the data reported in this article, the majority of the respondents perceived that the Schools of Medicine and Pharmacy at the University of Namibia applied assessment practices that yielded reliable and valid results. This was the case because most lecturers in the two schools used appropriate assessment tools and provided their students with prompt and informative feedback on the results of assignments, tests and examinations. In addition, most respondents reported that whereas examination procedures used in the two schools were efficient and effective, lecturers graded examination scripts fairly. These and other results are discussed in the article to communicate the message that the assessment procedures used in the Schools of Medicine and Pharmacy at the University of Namibia would promote effective learning and understanding amongst students as they were of high quality.

  7. Category Selectivity of Human Visual Cortex in Perception of Rubin Face–Vase Illusion

    Directory of Open Access Journals (Sweden)

    Xiaogang Wang

    2017-09-01

    Full Text Available When viewing the Rubin face–vase illusion, our conscious perception spontaneously alternates between the face and the vase; this illusion has been widely used to explore bistable perception. Previous functional magnetic resonance imaging (fMRI studies have studied the neural mechanisms underlying bistable perception through univariate and multivariate pattern analyses; however, no studies have investigated the issue of category selectivity. Here, we used fMRI to investigate the neural mechanisms underlying the Rubin face–vase illusion by introducing univariate amplitude and multivariate pattern analyses. The results from the amplitude analysis suggested that the activity in the fusiform face area was likely related to the subjective face perception. Furthermore, the pattern analysis results showed that the early visual cortex (EVC and the face-selective cortex could discriminate the activity patterns of the face and vase perceptions. However, further analysis of the activity patterns showed that only the face-selective cortex contains the face information. These findings indicated that although the EVC and face-selective cortex activities could discriminate the visual information, only the activity and activity pattern in the face-selective areas contained the category information of face perception in the Rubin face–vase illusion.

  8. Visual processing and social cognition in schizophrenia: relationships among eye movements, biological motion perception, and empathy.

    Science.gov (United States)

    Matsumoto, Yukiko; Takahashi, Hideyuki; Murai, Toshiya; Takahashi, Hidehiko

    2015-01-01

    Schizophrenia patients have impairments at several levels of cognition including visual attention (eye movements), perception, and social cognition. However, it remains unclear how lower-level cognitive deficits influence higher-level cognition. To elucidate the hierarchical path linking deficient cognitions, we focused on biological motion perception, which is involved in both the early stage of visual perception (attention) and higher social cognition, and is impaired in schizophrenia. Seventeen schizophrenia patients and 18 healthy controls participated in the study. Using point-light walker stimuli, we examined eye movements during biological motion perception in schizophrenia. We assessed relationships among eye movements, biological motion perception and empathy. In the biological motion detection task, schizophrenia patients showed lower accuracy and fixated longer than healthy controls. As opposed to controls, patients exhibiting longer fixation durations and fewer numbers of fixations demonstrated higher accuracy. Additionally, in the patient group, the correlations between accuracy and affective empathy index and between eye movement index and affective empathy index were significant. The altered gaze patterns in patients indicate that top-down attention compensates for impaired bottom-up attention. Furthermore, aberrant eye movements might lead to deficits in biological motion perception and finally link to social cognitive impairments. The current findings merit further investigation for understanding the mechanism of social cognitive training and its development. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  9. The visual and haptic contributions to hand perception.

    Science.gov (United States)

    Coelho, Lara A; Gonzalez, Claudia Lr

    2017-05-13

    Previous research has found that the perception of our hands is distorted. The characteristics of this distortion are an overestimation of hand width and an underestimation of finger length. The present study examined the role that different sensory modalities (vision and/or haptics) play in the perception of our hands. Participants pointed to their concealed hand in one of three groups: Vision+Haptics, Vision-only, or Haptics-only. Participants in the Vision+Haptics group had vision (non-informative) of the experimental setup and of the pointing hand, but no vision of the hand being estimated. They also experienced haptic feedback as the palm of the hand was in contact with the undersurface of a tabletop, where the estimations were made. Participants in the Vision-only group, instead of placing the hand to be estimated underneath the tabletop, they placed it behind their backs. Participants in this group were asked to imagine as if the hand was under the table when making their estimations. In the Haptics-only group, participants completed the task with the hand underneath the tabletop (as in the Vision+Haptics group) but did so while wearing a blindfold (no vision). All participants estimated the position of ten landmarks on the hand: the fingertip and the metacarpophalangeal joint of each digit. Hand maps were constructed using a 3D motion capture system. Participants in the Haptics-only group produced the most accurate hand maps. We discuss the possibility that vision interferes with somatosensory processing.

  10. The optomotor maze: a population assay for visual perception in Drosophila.

    Science.gov (United States)

    van Swinderen, Bruno

    2011-11-01

    Vision is a major sensory modality in Drosophila behavior, with more than one-half of the Drosophila brain devoted to visual processing. The mechanisms of vision in Drosophila can now be studied in individuals and in populations of flies by using various paradigms. The optomotor maze, described here, is a novel and efficient approach for querying visual perception in Drosophila populations. The optomotor maze setup is very simple: An eight-choice maze consisting of 3-mm paths grooved into a transparent Plexiglas or acrylic slab is placed over an upturned cathode ray tube (CRT) monitor on which visuals are displayed. The placement or movement of the visuals on the CRT, which the flies can see through the flat bottom of the maze, influences their turning behavior at each choice point. This paradigm can be adapted for visual learning by simply rerunning flies in the maze (habituation) or as a more sophisticated version of the aversive phototaxic suppression (APS) paradigm.

  11. [Complex visual hallucinations following occipital infarct and perception of optical illusions].

    Science.gov (United States)

    Renou, P; Deltour, S; Samson, Y

    2008-05-01

    The physiopathology of visual hallucinations in the hemianopic field secondary to occipital infarct is uncertain. We report the case of a patient with a history of occipital infarct who presented nonstereotyped complex hallucinations in the quadranopic field resulting from a second controlateral occipital infarct. Based on an experience with motion optical illusions, we suggested that the association of these two occipital lesions, involving the V5 motion area on the one side and the V1 area on the other side, could have produced the complex hallucinations due to a release phenomenon. The patient experienced simultaneously a double visual consciousness, with both hallucinations and real visual perceptions. The study of perceptual illusions in patients with visual hallucinations could illustrate the innovative theory of visual consciousness as being not unified but constituted of multiple microconsciousnesses.

  12. Benefit of spatial filtering for visual perception with a subretinal implant.

    Science.gov (United States)

    Rieger, Viola; Aryan, Naser Pour; Brendler, Christian; Rothermel, Albrecht

    2014-01-01

    Subretinal implants have proven to be capable of restoring vision to patients suffering from hereditary retinal degeneration diseases like retinitis pigmentosa and cone-rod dystrophy. Although they already provide basic visual perception, there is still much room for improvement in this field. Effects like electric field interference limit the visual acuity and may be the cause of the perceived vision to be blurred. This influence could be reduced by means of highpass spatial filtering. In this paper, based on the available reports about the visual perception parameters from the patients using the alpha-IMS subretinal implant, a model for the blurring effect of the patients retina is proposed. On this basis, highpass filters are suggested which will compensate the obscuring effect of the stimulator device plus retina system to some extent.

  13. Development of visual motion perception for prospective control: Brain and behavioural studies in infants

    Directory of Open Access Journals (Sweden)

    Seth B. Agyei

    2016-02-01

    Full Text Available During infancy, smart perceptual mechanisms develop allowing infants to judge time-space motion dynamics more efficiently with age and locomotor experience. This emerging capacity may be vital to enable preparedness for upcoming events and to be able to navigate in a changing environment. Little is known about brain changes that support the development of prospective control and about processes, such as preterm birth, that may compromise it. As a function of perception of visual motion, this paper will describe behavioural and brain studies with young infants investigating the development of visual perception for prospective control. By means of the three visual motion paradigms of occlusion, looming, and optic flow, our research shows the importance of including behavioural data when studying the neural correlates of prospective control.

  14. Grade 10 Students' perceptions of and attitudes toward science teaching and school science

    Science.gov (United States)

    Ebenezer, Jazlin V.; Zoller, Uri

    Grade 10 students' perceptions of classroom practices and activities, as well as their attitudes toward science teaching and school science, were assessed in the Westend School District (pseudonym) in British Columbia, using both quantitative (statistics of Likert-type scales) and qualitative (critical interpretive analysis of interview data) methods. The major findings of the study were that students do not appreciate the most prevailing contemporary practices in science classes, perceived by them as mainly the copying of the teacher's notes, and that they prefer science teaching and learning in which they take an active and responsible part. Additionally, teaching style appears to be the major determinant of high school students' attitudes toward science and science teaching. No change in students' perceptions of and attitudes toward science teaching and school science (in 1989 compared with 1986) could be detected in spite of the impact made by the recently advocated constructivist and science-technology-society (STS) approaches on science curriculum and science education. It is argued, therefore, that more emphasis must be placed on the science teachers' role and their teaching style if an educational change in the constructivist/STS direction is to be achieved.

  15. Effects of auditory vection speed and directional congruence on perceptions of visual vection

    Science.gov (United States)

    Gagliano, Isabella Alexis

    Spatial disorientation is a major contributor to aircraft mishaps. One potential contributing factor is vection, an illusion of self-motion. Although vection is commonly thought of as a visual illusion, it can also be produced through audition. The purpose of the current experiment was to explore interactions between conflicting visual and auditory vection cues, specifically with regard to the speed and direction of rotation. The ultimate goal was to explore the extent to which aural vection could diminish or enhance the perception of visual vection. The study used a 3 x 2 within-groups factorial design. Participants were exposed to three levels of aural rotation velocity (slower, matched, and faster, relative to visual rotation speed) and two levels of aural rotational congruence (congruent or incongruent rotation) including two control conditions (visual and aural-only). Dependent measures included vection onset time, vection direction judgements, subjective vection strength ratings, vection speed ratings, and horizontal nystagmus frequency. Subjective responses to motion were assessed pre and post treatment, and oculomotor responses were assessed before, during, and following exposure to circular vection. The results revealed a significant effect of stimulus condition on vection strength. Specifically, directionally-congruent aural-visual vection resulted in significantly stronger vection than visual and aural vection alone. Perceptions of directionally-congruent aural-visual vection were slightly stronger vection than directionally-incongruent aural-visual vection, but not significantly so. No significant effects of aural rotation velocity on vection strength were observed. The results suggest directionally-incongruent aural vection could be used as a countermeasure for visual vection and directionally-congruent aural vection could be used to improve vection in virtual environments, provided further research is done.

  16. Visual perception and stereoscopic imaging: an artist's perspective

    Science.gov (United States)

    Mason, Steve

    2015-03-01

    This paper continues my 2014 February IS and T/SPIE Convention exploration into the relationship of stereoscopic vision and consciousness (90141F-1). It was proposed then that by using stereoscopic imaging people may consciously experience, or see, what they are viewing and thereby help make them more aware of the way their brains manage and interpret visual information. Environmental imaging was suggested as a way to accomplish this. This paper is the result of further investigation, research, and follow-up imaging. A show of images, that is a result of this research, allows viewers to experience for themselves the effects of stereoscopy on consciousness. Creating dye-infused aluminum prints while employing ChromaDepth® 3D glasses, I hope to not only raise awareness of visual processing but also explore the differences and similarities between the artist and scientist―art increases right brain spatial consciousness, not only empirical thinking, while furthering the viewer's cognizance of the process of seeing. The artist must abandon preconceptions and expectations, despite what the evidence and experience may indicate in order to see what is happening in his work and to allow it to develop in ways he/she could never anticipate. This process is then revealed to the viewer in a show of work. It is in the experiencing, not just from the thinking, where insight is achieved. Directing the viewer's awareness during the experience using stereoscopic imaging allows for further understanding of the brain's function in the visual process. A cognitive transformation occurs, the preverbal "left/right brain shift," in order for viewers to "see" the space. Using what we know from recent brain research, these images will draw from certain parts of the brain when viewed in two dimensions and different ones when viewed stereoscopically, a shift, if one is looking for it, which is quite noticeable. People who have experienced these images in the context of examining their own

  17. Imposed visual feedback delay of an action changes mass perception based on the sensory prediction error

    Directory of Open Access Journals (Sweden)

    Takuya eHonda

    2013-10-01

    Full Text Available While performing an action, the timing of when the sensory feedback is given can be used to establish the causal link between the action and its consequence. It has been shown that delaying the visual feedback while carrying an object makes people feel the mass of the object to be greater, suggesting that the feedback timing can also impact the perceived quality of an external object. In this study, we investigated the origin of the feedback timing information that influences the mass perception of the external object.Participants made a straight reaching movement while holding a manipulandum. The movement of the manipulandum was presented as a cursor movement on a monitor. In Experiment 1, various delays were imposed between the actual trajectory and the cursor movement. The participants’ perceived mass of the manipulandum significantly increased as the delay increased to 400 ms, but this gain did not reach significance when the delay was 800 ms. This suggests the existence of a temporal tuning mechanism for incorporating the visual feedback into the perception of mass. In Experiment 2, we examined whether the increased mass perception during the visual delay was due to the prediction error of the visual consequence of an action or to the actual delay of the feedback itself. After the participants adapted to the feedback delay, the perceived mass of the object became lighter than before, indicating that updating the temporal prediction model for the visual consequence diminishes the overestimation of the object’s mass. We propose that the misattribution of the visual delay into mass perception is induced by the sensorimotor prediction error, possibly when the amount of delay (error is within the range that can reasonably include the consequence of an action.

  18. A framework for the first-person internal sensation of visual perception in mammals and a comparable circuitry for olfactory perception in Drosophila.

    Science.gov (United States)

    Vadakkan, Kunjumon I

    2015-01-01

    Perception is a first-person internal sensation induced within the nervous system at the time of arrival of sensory stimuli from objects in the environment. Lack of access to the first-person properties has limited viewing perception as an emergent property and it is currently being studied using third-person observed findings from various levels. One feasible approach to understand its mechanism is to build a hypothesis for the specific conditions and required circuit features of the nodal points where the mechanistic operation of perception take place for one type of sensation in one species and to verify it for the presence of comparable circuit properties for perceiving a different sensation in a different species. The present work explains visual perception in mammalian nervous system from a first-person frame of reference and provides explanations for the homogeneity of perception of visual stimuli above flicker fusion frequency, the perception of objects at locations different from their actual position, the smooth pursuit and saccadic eye movements, the perception of object borders, and perception of pressure phosphenes. Using results from temporal resolution studies and the known details of visual cortical circuitry, explanations are provided for (a) the perception of rapidly changing visual stimuli, (b) how the perception of objects occurs in the correct orientation even though, according to the third-person view, activity from the visual stimulus reaches the cortices in an inverted manner and (c) the functional significance of well-conserved columnar organization of the visual cortex. A comparable circuitry detected in a different nervous system in a remote species-the olfactory circuitry of the fruit fly Drosophila melanogaster-provides an opportunity to explore circuit functions using genetic manipulations, which, along with high-resolution microscopic techniques and lipid membrane interaction studies, will be able to verify the structure

  19. Effects of smartphone texting on the visual perception and dynamic walking stability.

    Science.gov (United States)

    Lim, Jongil; Chang, Seung Ho; Lee, Jihyun; Kim, Kijeong

    2017-02-01

    Mobile phone use while walking can cause dual-task interference and increases safety risks by increasing attentional and cognitive demands. While the interference effect on cognitive function has been examined extensively, how perception of the environment and walking dynamics are affected by mobile phone use while walking is not well understood. The amount of visual information loss and its consequent impact on dynamic walking stability was examined in this study. Young adults (mean, 20.3 years) volunteered and walked on a treadmill while texting and attending to visual tasks simultaneously. Performance of visual task, field of regard loss, and margin of stability under dual-task conditions were compared with those of single-task conditions (i.e., visual task only). The results revealed that the size of visual field and visual acuity demand were varied across the visual task conditions. Approximately half of the visual cues provided during texting while walking were not perceived as compared to the visual task only condition. The field of regard loss also increased with increased dual-task cost of mobile phone use. Dynamic walking stability, however, showed no significant differences between the conditions. Taken together, the results demonstrate that the loss of situational awareness is unavoidable and occurs simultaneously with decrements in concurrent task performance. The study indicates the importance of considering the nature of attentional resources for the studies in dual-task paradigm and may provide practical information to improve the safe use of mobile phones while walking.

  20. Effect of Digital Portfolio Assessment on Mathematics Attitudes and Self-Perceptions of Sixth- through Eighth-Grade Students

    Science.gov (United States)

    Reynolds, Betty Gulin

    2010-01-01

    The purpose of this study was to determine to what extent digital portfolios would affect mathematics achievement, attitudes, and self-perceptions of themselves as mathematics learners of sixth-, seventh-, and eighth-grade students. The study analyzed the effect of digital portfolios on the students' performance on the Iowa Test of Basic Skills.…

  1. PROFESSIONAL ACCOUNTING ETHICS: A VISUAL ANALYSIS OF PUBLIC PERCEPTION

    Directory of Open Access Journals (Sweden)

    Renato Ferreira Leitão Azevedo

    2012-03-01

    Full Text Available The decline in both the number and quality of students choosing accounting programs has been a worldwide source of concern to scholars and practitioners. According to Albrecht and Sack (2000, that decline is a consequence of several factors, such as changes in business environment, decrease in salary levels and development of alternative careers perceived as more attractive by students and lack of information and/or misunderstanding related to accounting careers. For Carnegie and Napier (2010, comprehension of such external images related to accounting careers and accountants is important for assessing the roles of these professionals in a wider social context. The success of the accounting profession, according to Belski et al. (2004, largely depends on how it is viewed by the public, considering that the image of the accounting profession has been damaged in the recent past by the widely publicized accounting frauds, scandals and failures involving accounting firms and accountants. To support a better understanding of this phenomenon, the objective of this study is to identify and analyze whether the accounting profession is negatively stereotyped by public perception according to ethics. Based on an adapted photo-survey, with 1,034 randomly selected respondents, and tests of differences between means, the central hypothesis of this study was rejected: it is not possible to state that accounting professionals are negatively stereotyped for professional ethics. Also, there were no significant differences based on gender, academic background or education levels of the respondents, but on the other hand is possible to confirm a positive perception based on confidence interval analysis. Implications for practice and recommendations for future studies are both presented in the last section.

  2. Phonological Contribution during Visual Word Recognition in Child Readers. An Intermodal Priming Study in Grades 3 and 5

    Science.gov (United States)

    Sauval, Karinne; Casalis, Séverine; Perre, Laetitia

    2017-01-01

    This study investigated the phonological contribution during visual word recognition in child readers as a function of general reading expertise (third and fifth grades) and specific word exposure (frequent and less-frequent words). An intermodal priming in lexical decision task was performed. Auditory primes (identical and unrelated) were used in…

  3. Guidelines for assigning allowable properties to visually graded foreign species based on test data from full sized specimens

    Science.gov (United States)

    David W. Green; Bradley E. Shelley

    2006-01-01

    The objective of this document is to provide philosophy and guidelines for the assignment of allowable properties to visually graded dimension lumber produced from trees not grown in the United States. This document assumes, as a starting point, the procedures of ASTM D 1990.

  4. Ventral aspect of the visual form pathway is not critical for the perception of biological motion

    Science.gov (United States)

    Gilaie-Dotan, Sharon; Saygin, Ayse Pinar; Lorenzi, Lauren J.; Rees, Geraint; Behrmann, Marlene

    2015-01-01

    Identifying the movements of those around us is fundamental for many daily activities, such as recognizing actions, detecting predators, and interacting with others socially. A key question concerns the neurobiological substrates underlying biological motion perception. Although the ventral “form” visual cortex is standardly activated by biologically moving stimuli, whether these activations are functionally critical for biological motion perception or are epiphenomenal remains unknown. To address this question, we examined whether focal damage to regions of the ventral visual cortex, resulting in significant deficits in form perception, adversely affects biological motion perception. Six patients with damage to the ventral cortex were tested with sensitive point-light display paradigms. All patients were able to recognize unmasked point-light displays and their perceptual thresholds were not significantly different from those of three different control groups, one of which comprised brain-damaged patients with spared ventral cortex (n > 50). Importantly, these six patients performed significantly better than patients with damage to regions critical for biological motion perception. To assess the necessary contribution of different regions in the ventral pathway to biological motion perception, we complement the behavioral findings with a fine-grained comparison between the lesion location and extent, and the cortical regions standardly implicated in biological motion processing. This analysis revealed that the ventral aspects of the form pathway (e.g., fusiform regions, ventral extrastriate body area) are not critical for biological motion perception. We hypothesize that the role of these ventral regions is to provide enhanced multiview/posture representations of the moving person rather than to represent biological motion perception per se. PMID:25583504

  5. Individual differences in visual motion perception and neurotransmitter concentrations in the human brain.

    Science.gov (United States)

    Takeuchi, Tatsuto; Yoshimoto, Sanae; Shimada, Yasuhiro; Kochiyama, Takanori; Kondo, Hirohito M

    2017-02-19

    Recent studies have shown that interindividual variability can be a rich source of information regarding the mechanism of human visual perception. In this study, we examined the mechanisms underlying interindividual variability in the perception of visual motion, one of the fundamental components of visual scene analysis, by measuring neurotransmitter concentrations using magnetic resonance spectroscopy. First, by psychophysically examining two types of motion phenomena-motion assimilation and contrast-we found that, following the presentation of the same stimulus, some participants perceived motion assimilation, while others perceived motion contrast. Furthermore, we found that the concentration of the excitatory neurotransmitter glutamate-glutamine (Glx) in the dorsolateral prefrontal cortex (Brodmann area 46) was positively correlated with the participant's tendency to motion assimilation over motion contrast; however, this effect was not observed in the visual areas. The concentration of the inhibitory neurotransmitter γ-aminobutyric acid had only a weak effect compared with that of Glx. We conclude that excitatory process in the suprasensory area is important for an individual's tendency to determine antagonistically perceived visual motion phenomena.This article is part of the themed issue 'Auditory and visual scene analysis'. © 2017 The Author(s).

  6. Early visual responses predict conscious face perception within and between subjects during binocular rivalry.

    Science.gov (United States)

    Sandberg, Kristian; Bahrami, Bahador; Kanai, Ryota; Barnes, Gareth Robert; Overgaard, Morten; Rees, Geraint

    2013-06-01

    Previous studies indicate that conscious face perception may be related to neural activity in a large time window around 170-800 msec after stimulus presentation, yet in the majority of these studies changes in conscious experience are confounded with changes in physical stimulation. Using multivariate classification on MEG data recorded when participants reported changes in conscious perception evoked by binocular rivalry between a face and a grating, we showed that only MEG signals in the 120-320 msec time range, peaking at the M170 around 180 msec and the P2m at around 260 msec, reliably predicted conscious experience. Conscious perception could not only be decoded significantly better than chance from the sensors that showed the largest average difference, as previous studies suggest, but also from patterns of activity across groups of occipital sensors that individually were unable to predict perception better than chance. In addition, source space analyses showed that sources in the early and late visual system predicted conscious perception more accurately than frontal and parietal sites, although conscious perception could also be decoded there. Finally, the patterns of neural activity associated with conscious face perception generalized from one participant to another around the times of maximum prediction accuracy. Our work thus demonstrates that the neural correlates of particular conscious contents (here, faces) are highly consistent in time and space within individuals and that these correlates are shared to some extent between individuals.

  7. 'I didn't see that coming': simulated visual fields and driving hazard perception test performance.

    Science.gov (United States)

    Glen, Fiona C; Smith, Nicholas D; Jones, Lee; Crabb, David P

    2016-09-01

    Evidence is limited regarding specific types of visual field loss associated with unsafe driving. We use novel gaze-contingent software to examine the effect of simulated visual field loss on computer-based driving hazard detection with the specific aim of testing the impact of scotomata located to the right and left of fixation. The 'hazard perception test' is a component of the UK driving licence examination, which measures speed of detecting 15 different hazards in a series of real-life driving films. We have developed a novel eye-tracking and computer set up capable of generating a realistic gaze-contingent scotoma simulation (GazeSS) overlaid on film content. Thirty drivers with healthy vision completed three versions of the hazard perception test in a repeated measures experiment. In two versions, GazeSS simulated a scotoma in the binocular field of view to the left or right of fixation. A third version was unmodified to establish baseline performance. Participants' mean baseline hazard perception test score was 51 ± 7 (out of 75). This reduced to 46 ± 9 and 46 ± 11 when completing the task with a binocular visual field defect located to the left and right of fixation, respectively. While the main effect of simulated visual field loss on performance was statistically significant (p = 0.007), there were no average differences in the experimental conditions where a scotoma was located in the binocular visual field to the right or left of fixation. Simulated visual field loss impairs driving hazard detection on a computer-based test. There was no statistically significant difference in average performance when the simulated scotoma was located to the right or left of fixation of the binocular visual field, but certain types of hazard caused more difficulties than others. © 2016 Optometry Australia.

  8. Perception of angle in visual categorization by pigeons (Columba livia.

    Directory of Open Access Journals (Sweden)

    Walter T. Herbranson

    2017-08-01

    Full Text Available Pigeons are capable of learning to categorize stimuli based on visual features, and often reach levels of accuracy comparable with humans. Nevertheless, recent research has suggested that the cognitive processes behind categorization in pigeons and humans may not always be the same. Pigeons learned a categorization task in which they categorized either Shepard circles varying in size and orientation of a radial line (stimuli that are frequently used in research on human categorization, or moving dots varying in speed and direction of travel (stimuli that have been successfully used to study pigeon categorization. Even though categories were balanced so that the angles of orientation of Shepard circles matched the directions of travel for moving dots, birds failed to learn categories based on the former but not the latter. Results suggest that information about angle as a direction of travel may be more important for pigeons than information about angle of orientation.

  9. Visual speech acts differently than lexical context in supporting speech perception.

    Science.gov (United States)

    Samuel, Arthur G; Lieblich, Jerrold

    2014-08-01

    The speech signal is often badly articulated, and heard under difficult listening conditions. To deal with these problems, listeners make use of various types of context. In the current study, we examine a type of context that in previous work has been shown to affect how listeners report what they hear: visual speech (i.e., the visible movements of the speaker's articulators). Despite the clear utility of this type of context under certain conditions, prior studies have shown that visually driven phonetic percepts (via the "McGurk" effect) are not "real" enough to affect perception of later-occurring speech; such percepts have not produced selective adaptation effects. This failure contrasts with successful adaptation by sounds that are generated by lexical context-the word that a sound occurs within. We demonstrate here that this dissociation is robust, leading to the conclusion that visual and lexical contexts operate differently. We suggest that the dissociation reflects the dual nature of speech as both a perceptual object and a linguistic object. Visual speech seems to contribute directly to the computations of the perceptual object but not the linguistic one, while lexical context is used in both types of computations.

  10. Implied dynamics biases the visual perception of velocity.

    Directory of Open Access Journals (Sweden)

    Barbara La Scaleia

    Full Text Available We expand the anecdotic report by Johansson that back-and-forth linear harmonic motions appear uniform. Six experiments explore the role of shape and spatial orientation of the trajectory of a point-light target in the perceptual judgment of uniform motion. In Experiment 1, the target oscillated back-and-forth along a circular arc around an invisible pivot. The imaginary segment from the pivot to the midpoint of the trajectory could be oriented vertically downward (consistent with an upright pendulum, horizontally leftward, or vertically upward (upside-down. In Experiments 2 to 5, the target moved uni-directionally. The effect of suppressing the alternation of movement directions was tested with curvilinear (Experiment 2 and 3 or rectilinear (Experiment 4 and 5 paths. Experiment 6 replicated the upright condition of Experiment 1, but participants were asked to hold the gaze on a fixation point. When some features of the trajectory evoked the motion of either a simple pendulum or a mass-spring system, observers identified as uniform the kinematic profiles close to harmonic motion. The bias towards harmonic motion was most consistent in the upright orientation of Experiment 1 and 6. The bias disappeared when the stimuli were incompatible with both pendulum and mass-spring models (Experiments 3 to 5. The results are compatible with the hypothesis that the perception of dynamic stimuli is biased by the laws of motion obeyed by natural events, so that only natural motions appear uniform.

  11. Implied Dynamics Biases the Visual Perception of Velocity

    Science.gov (United States)

    La Scaleia, Barbara; Zago, Myrka; Moscatelli, Alessandro; Lacquaniti, Francesco; Viviani, Paolo

    2014-01-01

    We expand the anecdotic report by Johansson that back-and-forth linear harmonic motions appear uniform. Six experiments explore the role of shape and spatial orientation of the trajectory of a point-light target in the perceptual judgment of uniform motion. In Experiment 1, the target oscillated back-and-forth along a circular arc around an invisible pivot. The imaginary segment from the pivot to the midpoint of the trajectory could be oriented vertically downward (consistent with an upright pendulum), horizontally leftward, or vertically upward (upside-down). In Experiments 2 to 5, the target moved uni-directionally. The effect of suppressing the alternation of movement directions was tested with curvilinear (Experiment 2 and 3) or rectilinear (Experiment 4 and 5) paths. Experiment 6 replicated the upright condition of Experiment 1, but participants were asked to hold the gaze on a fixation point. When some features of the trajectory evoked the motion of either a simple pendulum or a mass-spring system, observers identified as uniform the kinematic profiles close to harmonic motion. The bias towards harmonic motion was most consistent in the upright orientation of Experiment 1 and 6. The bias disappeared when the stimuli were incompatible with both pendulum and mass-spring models (Experiments 3 to 5). The results are compatible with the hypothesis that the perception of dynamic stimuli is biased by the laws of motion obeyed by natural events, so that only natural motions appear uniform. PMID:24667578

  12. Visual Perception Studies in CT images obtained lo low dose

    International Nuclear Information System (INIS)

    Adame Brooks, D.; Miller-Clemente, R. A.

    2015-01-01

    This paper has as aims to describe a strategy to evaluate the diagnostic quality of obtained images of method for dose reduction, with the purpose of determining the dose value or values from which the image quality is significantly degraded making it insufficient for the diagnostic. To complement and have an estimate of the quality of the images we established a group of measures of objective type, and the diagnostic quality of the images was evaluated through a group of observers using the analysis ROC and LROC. For ROC and LROC analyzes the behavior of the area under the curve in relation to the four proposed dose levels was obtained. For high dose levels, detection was good. The values of area under the curve decreased as the dose rate decreased, falling to values indicating low accuracy in diagnosis. This result indicates that the area under the curve decreases by the dose rate. We conclude that the objective quality measures selected are representative of the changes that occur in the resulting image and provided information on changes in the perception of observers. The experiments ROC and LROC allowed determine the range of dose values from which the image degradation causes a low accuracy in the diagnostic. (Author)

  13. Implied dynamics biases the visual perception of velocity.

    Science.gov (United States)

    La Scaleia, Barbara; Zago, Myrka; Moscatelli, Alessandro; Lacquaniti, Francesco; Viviani, Paolo

    2014-01-01

    We expand the anecdotic report by Johansson that back-and-forth linear harmonic motions appear uniform. Six experiments explore the role of shape and spatial orientation of the trajectory of a point-light target in the perceptual judgment of uniform motion. In Experiment 1, the target oscillated back-and-forth along a circular arc around an invisible pivot. The imaginary segment from the pivot to the midpoint of the trajectory could be oriented vertically downward (consistent with an upright pendulum), horizontally leftward, or vertically upward (upside-down). In Experiments 2 to 5, the target moved uni-directionally. The effect of suppressing the alternation of movement directions was tested with curvilinear (Experiment 2 and 3) or rectilinear (Experiment 4 and 5) paths. Experiment 6 replicated the upright condition of Experiment 1, but participants were asked to hold the gaze on a fixation point. When some features of the trajectory evoked the motion of either a simple pendulum or a mass-spring system, observers identified as uniform the kinematic profiles close to harmonic motion. The bias towards harmonic motion was most consistent in the upright orientation of Experiment 1 and 6. The bias disappeared when the stimuli were incompatible with both pendulum and mass-spring models (Experiments 3 to 5). The results are compatible with the hypothesis that the perception of dynamic stimuli is biased by the laws of motion obeyed by natural events, so that only natural motions appear uniform.

  14. Fornix and medial temporal lobe lesions lead to comparable deficits in complex visual perception.

    Science.gov (United States)

    Lech, Robert K; Koch, Benno; Schwarz, Michael; Suchan, Boris

    2016-05-04

    Recent research dealing with the structures of the medial temporal lobe (MTL) has shifted away from exclusively investigating memory-related processes and has repeatedly incorporated the investigation of complex visual perception. Several studies have demonstrated that higher level visual tasks can recruit structures like the hippocampus and perirhinal cortex in order to successfully perform complex visual discriminations, leading to a perceptual-mnemonic or representational view of the medial temporal lobe. The current study employed a complex visual discrimination paradigm in two patients suffering from brain lesions with differing locations and origin. Both patients, one with extensive medial temporal lobe lesions (VG) and one with a small lesion of the anterior fornix (HJK), were impaired in complex discriminations while showing otherwise mostly intact cognitive functions. The current data confirmed previous results while also extending the perceptual-mnemonic theory of the MTL to the main output structure of the hippocampus, the fornix. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Visual perception of complex shape-transforming processes.

    Science.gov (United States)

    Schmidt, Filipp; Fleming, Roland W

    2016-11-01

    Morphogenesis-or the origin of complex natural form-has long fascinated researchers from practically every branch of science. However, we know practically nothing about how we perceive and understand such processes. Here, we measured how observers visually infer shape-transforming processes. Participants viewed pairs of objects ('before' and 'after' a transformation) and identified points that corresponded across the transformation. This allowed us to map out in spatial detail how perceived shape and space were affected by the transformations. Participants' responses were strikingly accurate and mutually consistent for a wide range of non-rigid transformations including complex growth-like processes. A zero-free-parameter model based on matching and interpolating/extrapolating the positions of high-salience contour features predicts the data surprisingly well, suggesting observers infer spatial correspondences relative to key landmarks. Together, our findings reveal the operation of specific perceptual organization processes that make us remarkably adept at identifying correspondences across complex shape-transforming processes by using salient object features. We suggest that these abilities, which allow us to parse and interpret the causally significant features of shapes, are invaluable for many tasks that involve 'making sense' of shape. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Visual Perception and Visual-Motor Integration in Very Preterm and/or Very Low Birth Weight Children: A Meta-Analysis

    Science.gov (United States)

    Geldof, C. J. A.; van Wassenaer, A. G.; de Kieviet, J. F.; Kok, J. H.; Oosterlaan, J.

    2012-01-01

    A range of neurobehavioral impairments, including impaired visual perception and visual-motor integration, are found in very preterm born children, but reported findings show great variability. We aimed to aggregate the existing literature using meta-analysis, in order to provide robust estimates of the effect of very preterm birth on visual…

  17. Vividness of visual imagery depends on the neural overlap with perception in visual areas

    NARCIS (Netherlands)

    Dijkstra, N.; Bosch, S.E.; Gerven, M.A.J. van

    2017-01-01

    Research into the neural correlates of individual differences in imagery vividness point to an important role of the early visual cortex. However, there is also great fluctuation of vividness within individuals, such that only looking at differences between people necessarily obscures the picture.

  18. Syntactic texture and perception for a new generic visual anomalies classification

    Science.gov (United States)

    Désage, Simon-Frédéric; Pitard, Gilles; Pillet, Maurice; Favrelière, Hugues; Maire, Jean-Luc; Frelin, Fabrice; Samper, Serge; Le Goïc, Gaëtan

    2015-04-01

    The research purpose is to improve aesthetic anomalies detection and evaluation based on what is perceived by human eye and on the 2006 CIE report.1 It is therefore important to define parameters able to discriminate surfaces, in accordance with the perception of human eye. Our starting point in assessing aesthetic anomalies is geometric description such as defined by ISO standard,2 i.e. traduce anomalies description with perception words about texture divergence impact. However, human controllers observe (detect) the aesthetic anomaly by its visual effect and interpreter for its geometric description. The research question is how define generic parameters for discriminating aesthetic anomalies, from enhanced information of visual texture such as recent surface visual rendering approach. We propose to use an approach from visual texture processing that quantify spatial variations of pixel for translating changes in color, material and relief. From a set of images from different angles of light which gives us access to the surface appearance, we propose an approach from visual effect to geometrical specifications as the current standards have identified the aesthetic anomalies.

  19. [Social behavior, musicality and visual perception in monogloid children (author's transl)].

    Science.gov (United States)

    Rabensteiner, B

    1975-01-01

    Forty-nine mongoloid and 48 non-mongol test persons of equivalent age and intelligence were selected and studied with respect to social behavior, speech disorders (observation of behavior), musicality and visual perception. There were significant differences in favor of the mongols with respect to social adaption. Speech disorders of all kinds occurred significantly more frequently in mongol children; stuttering was significantly more frequent in the boys. The mongol group did significantly better in the musicality test; the difference in the rhythmical part was highly significant. The average differences in the capacity for visual discrimination of colors, geometrical forms and the spatial relationship of geometrical forms were not significant.

  20. Enhancement of visual perception with use of dynamic cues.

    Science.gov (United States)

    Andia, Marcelo E; Plett, Johannes; Tejos, Cristian; Guarini, Marcelo W; Navarro, María E; Razmilic, Dravna; Meneses, Luis; Villalon, Manuel J; Irarrazaval, Pablo

    2009-02-01

    Institutional review board approval and signed informed consent were not needed, as medical images included in public databases were used in this study. The purpose of this study was to improve the detection of microcalcifications on mammograms and lung nodules on chest radiographs by using the dynamic cues algorithm and the motion and flickering sensitivity of the human visual system (HVS). Different sets of mammograms from the Mammographic Image Analysis Society database and chest radiographs from the Japanese Society of Radiological Technology database were presented statically, as is standard, and in a video sequence generated with the dynamic cues algorithm. Nine observers were asked to rate the presence of abnormalities with a five-point scale (1, definitely not present; 5, definitely present). The data were analyzed with receiver operating characteristic (ROC) techniques and the Dorfman-Berbaum-Metz method. The video sequence generated with the dynamic cues algorithm increased the rate of detection of microcalcifications by 10.2% (P = .002) compared with that obtained with the standard static method, as measured by the area under the ROC curve. Similar results were obtained for lung nodules, with an increase of 12.3% (P = .0054). The increase in the rate of correct detection did not come just from the image contrast change produced by the algorithm but also from the fact that image frames generated with the dynamic cues algorithm were put together in a video sequence so that the motion sensitivity of the HVS could be used to facilitate the detection of low-contrast objects. http://radiology.rsnajnls.org/cgi/content/full/250/2/551/DC1.

  1. A Model of Generating Visual Place Cells Based on Environment Perception and Similar Measure

    Directory of Open Access Journals (Sweden)

    Yang Zhou

    2016-01-01

    Full Text Available It is an important content to generate visual place cells (VPCs in the field of bioinspired navigation. By analyzing the firing characteristic of biological place cells and the existing methods for generating VPCs, a model of generating visual place cells based on environment perception and similar measure is abstracted in this paper. VPCs’ generation process is divided into three phases, including environment perception, similar measure, and recruiting of a new place cell. According to this process, a specific method for generating VPCs is presented. External reference landmarks are obtained based on local invariant characteristics of image and a similar measure function is designed based on Euclidean distance and Gaussian function. Simulation validates the proposed method is available. The firing characteristic of the generated VPCs is similar to that of biological place cells, and VPCs’ firing fields can be adjusted flexibly by changing the adjustment factor of firing field (AFFF and firing rate’s threshold (FRT.

  2. Confinement has no effect on visual space perception: The results of the Mars-500 experiment

    Czech Academy of Sciences Publication Activity Database

    Šikl, Radovan; Šimeček, Michal

    2014-01-01

    Roč. 76, č. 2 (2014), s. 438-451 ISSN 1943-3921 R&D Projects: GA ČR(CZ) GAP407/12/2528 Institutional support: RVO:68081740 Keywords : visual space perception * perspective * Mars-500 * size judgment * size constancy * confinement Subject RIV: AN - Psychology Impact factor: 2.168, year: 2014 http://dx.doi.org/10.3758/s13414-013-0594-y

  3. The changes in perception of visual illusions during long-term isolation

    Czech Academy of Sciences Publication Activity Database

    Šikl, Radovan; Šimeček, Michal; Lukavský, Jiří

    2009-01-01

    Roč. 2009, č. 38 (2009), s. 31-32 ISSN 0301-0066. [European Conference on Visual Perception. 24.08.2009-28.08.2009, Regensburg] R&D Projects: GA ČR GA406/09/2003 Institutional research plan: CEZ:AV0Z70250504 Keywords : long-term isolation * geometrical illusions * perspective Subject RIV: AN - Psychology http://www.perceptionweb.com/abstract.cgi?id=v090766

  4. Confinement has no effect on visual space perception: The results of the Mars-500 experiment

    Czech Academy of Sciences Publication Activity Database

    Šikl, Radovan; Šimeček, Michal

    2014-01-01

    Roč. 76, č. 2 (2014), s. 438-451 ISSN 1943-3921 R&D Project s: GA ČR(CZ) GAP407/12/2528 Institutional support: RVO:68081740 Keywords : visual space perception * perspective * Mars-500 * size judgment * size constancy * confinement Subject RIV: AN - Psychology Impact factor: 2.168, year: 2014 http://dx.doi.org/10.3758/s13414-013-0594-y

  5. Effects of smartphone texting on the visual perception and dynamic walking stability

    OpenAIRE

    Lim, Jongil; Chang, Seung Ho; Lee, Jihyun; Kim, Kijeong

    2017-01-01

    Mobile phone use while walking can cause dual-task interference and increases safety risks by increasing attentional and cognitive demands. While the interference effect on cognitive function has been examined extensively, how perception of the environment and walking dynamics are affected by mobile phone use while walking is not well understood. The amount of visual information loss and its consequent impact on dynamic walking stability was examined in this study. Young adults (mean, 20.3 ye...

  6. A systematic review of the technology-based assessment of visual perception and exploration behaviour in association football.

    Science.gov (United States)

    McGuckian, Thomas B; Cole, Michael H; Pepping, Gert-Jan

    2018-04-01

    To visually perceive opportunities for action, athletes rely on the movements of their eyes, head and body to explore their surrounding environment. To date, the specific types of technology and their efficacy for assessing the exploration behaviours of association footballers have not been systematically reviewed. This review aimed to synthesise the visual perception and exploration behaviours of footballers according to the task constraints, action requirements of the experimental task, and level of expertise of the athlete, in the context of the technology used to quantify the visual perception and exploration behaviours of footballers. A systematic search for papers that included keywords related to football, technology, and visual perception was conducted. All 38 included articles utilised eye-movement registration technology to quantify visual perception and exploration behaviour. The experimental domain appears to influence the visual perception behaviour of footballers, however no studies investigated exploration behaviours of footballers in open-play situations. Studies rarely utilised representative stimulus presentation or action requirements. To fully understand the visual perception requirements of athletes, it is recommended that future research seek to validate alternate technologies that are capable of investigating the eye, head and body movements associated with the exploration behaviours of footballers during representative open-play situations.

  7. An effective visualization technique for depth perception in augmented reality-based surgical navigation.

    Science.gov (United States)

    Choi, Hyunseok; Cho, Byunghyun; Masamune, Ken; Hashizume, Makoto; Hong, Jaesung

    2016-03-01

    Depth perception is a major issue in augmented reality (AR)-based surgical navigation. We propose an AR and virtual reality (VR) switchable visualization system with distance information, and evaluate its performance in a surgical navigation set-up. To improve depth perception, seamless switching from AR to VR was implemented. In addition, the minimum distance between the tip of the surgical tool and the nearest organ was provided in real time. To evaluate the proposed techniques, five physicians and 20 non-medical volunteers participated in experiments. Targeting error, time taken, and numbers of collisions were measured in simulation experiments. There was a statistically significant difference between a simple AR technique and the proposed technique. We confirmed that depth perception in AR could be improved by the proposed seamless switching between AR and VR, and providing an indication of the minimum distance also facilitated the surgical tasks. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Shape Perception in 3-D Scatterplots Using Constant Visual Angle Glyphs

    DEFF Research Database (Denmark)

    Stenholt, Rasmus; Madsen, Claus B.

    2012-01-01

    When viewing 3-D scatterplots in immersive virtual environments, one commonly encountered problem is the presence of clutter, which obscures the view of any structures of interest in the visualization. In order to solve this problem, we propose to render the 3-D glyphs such that they always cover...... the prospect of dealing with clutter, but also the prospect of allowing for a better perception of the continuous shapes of structures in 3-D scatterplots. In a formal user evaluation of CVA glyphs, the results indicate that such glyphs do allow for better perception of shapes in 3-D scatterplots compared...... to regular perspective glyphs, especially when a large amount of clutter is present. Furthermore, our evaluation revealed that perception of structures in 3-D scatterplots is significantly affected by the volumetric density of the glyphs in the plot....

  9. Contextual effects of scene on the visual perception of object orientation in depth.

    Directory of Open Access Journals (Sweden)

    Ryosuke Niimi

    Full Text Available We investigated the effect of background scene on the human visual perception of depth orientation (i.e., azimuth angle of three-dimensional common objects. Participants evaluated the depth orientation of objects. The objects were surrounded by scenes with an apparent axis of the global reference frame, such as a sidewalk scene. When a scene axis was slightly misaligned with the gaze line, object orientation perception was biased, as if the gaze line had been assimilated into the scene axis (Experiment 1. When the scene axis was slightly misaligned with the object, evaluated object orientation was biased, as if it had been assimilated into the scene axis (Experiment 2. This assimilation may be due to confusion between the orientation of the scene and object axes (Experiment 3. Thus, the global reference frame may influence object orientation perception when its orientation is similar to that of the gaze-line or object.

  10. VISUAL PERCEPTION OF THE CHILDREN WITH PLEXUS BRACHIALIS DAMAGE – ASSESSMENT AND TREATMENT

    Directory of Open Access Journals (Sweden)

    Dragana M. KLJAJIKJ

    2012-03-01

    Full Text Available Interpersonal communication, psychosocial and mental development of personality and its all other functions take place through the motor control. The most common neurological syndrome is a type of peripheral paresis/paralysis of plexus bracialis, which in most cases occurs at birth and significantly compromises the growth and development of the upper extremities and affects the psychomotor performance. The aim of this study was to evaluate the level of visual perception in children with lesion of plexus brachialis and the effect of the somatopedic treatment over the level of increase of the visual perception. The study sample was consisted of 60 preschool children accommodated at the Rehabilitation Centre “Dr. Miroslav Zotović” in Belgrade (experimental group and examiners that followed regular checkups and had discontinuity in their therapy (control group. For the research purposes, we used The Test for Visual Perception Assessment. By analyzing the results, we concluded that in both, in the first and the second measuring there was a statistically significant correlation between the experimental and the control groups (I measuring: p<0.001, r = 0.408; II measuring: p <0.001, r = 0.593.

  11. Global perception depends on coherent work of bilateral visual cortices: transcranial magnetic stimulation (TMS) studies.

    Science.gov (United States)

    Zhang, Xin; Han, ShiHui

    2007-08-01

    Previous research suggests that the right and left hemispheres dominate global and local perception of hierarchical patterns, respectively. The current work examined whether global perception of hierarchical stimuli requires coherent work of bilateral visual cortices using transcranial magnetic stimulation (TMS). Subjects discriminated global or local properties of compound letters in Experiment 1. Reaction times were recorded when single-pulse real TMS or sham TMS was delivered over the left or right visual cortex. While a global precedence effect (i.e., faster responses to global than local targets and stronger global-to-local interference than the reverse) was observed, TMS decreased global-to-local interference whereas increased local-to-global interference. Experiment 2 ruled out the possibility that the effects observed in Experiment 1 resulted from perceptual learning. Experiment 3 used compound shapes and observed TMS effect similar to that in Experiment 1. Moreover, TMS also slowed global RTs whereas speeded up local RTs in Experiment 3. Finally, the TMS effects observed in Experiments 1 and 3 did not differ between the conditions when TMS was applied over the left and right hemispheres. The results support a coherence hypothesis that global perception of compound stimuli depends upon the coherent work of bilateral visual cortices.

  12. Within- and cross-modal distance information disambiguate visual size-change perception.

    Directory of Open Access Journals (Sweden)

    Peter W Battaglia

    2010-03-01

    Full Text Available Perception is fundamentally underconstrained because different combinations of object properties can generate the same sensory information. To disambiguate sensory information into estimates of scene properties, our brains incorporate prior knowledge and additional "auxiliary" (i.e., not directly relevant to desired scene property sensory information to constrain perceptual interpretations. For example, knowing the distance to an object helps in perceiving its size. The literature contains few demonstrations of the use of prior knowledge and auxiliary information in combined visual and haptic disambiguation and almost no examination of haptic disambiguation of vision beyond "bistable" stimuli. Previous studies have reported humans integrate multiple unambiguous sensations to perceive single, continuous object properties, like size or position. Here we test whether humans use visual and haptic information, individually and jointly, to disambiguate size from distance. We presented participants with a ball moving in depth with a changing diameter. Because no unambiguous distance information is available under monocular viewing, participants rely on prior assumptions about the ball's distance to disambiguate their -size percept. Presenting auxiliary binocular and/or haptic distance information augments participants' prior distance assumptions and improves their size judgment accuracy-though binocular cues were trusted more than haptic. Our results suggest both visual and haptic distance information disambiguate size perception, and we interpret these results in the context of probabilistic perceptual reasoning.

  13. The perception of naturalness correlates with low-level visual features of environmental scenes.

    Directory of Open Access Journals (Sweden)

    Marc G Berman

    Full Text Available Previous research has shown that interacting with natural environments vs. more urban or built environments can have salubrious psychological effects, such as improvements in attention and memory. Even viewing pictures of nature vs. pictures of built environments can produce similar effects. A major question is: What is it about natural environments that produces these benefits? Problematically, there are many differing qualities between natural and urban environments, making it difficult to narrow down the dimensions of nature that may lead to these benefits. In this study, we set out to uncover visual features that related to individuals' perceptions of naturalness in images. We quantified naturalness in two ways: first, implicitly using a multidimensional scaling analysis and second, explicitly with direct naturalness ratings. Features that seemed most related to perceptions of naturalness were related to the density of contrast changes in the scene, the density of straight lines in the scene, the average color saturation in the scene and the average hue diversity in the scene. We then trained a machine-learning algorithm to predict whether a scene was perceived as being natural or not based on these low-level visual features and we could do so with 81% accuracy. As such we were able to reliably predict subjective perceptions of naturalness with objective low-level visual features. Our results can be used in future studies to determine if these features, which are related to naturalness, may also lead to the benefits attained from interacting with nature.

  14. Enhanced visual awareness for morality and pajamas? Perception vs. memory in 'top-down' effects.

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    Firestone, Chaz; Scholl, Brian J

    2015-03-01

    A raft of prominent findings has revived the notion that higher-level cognitive factors such as desire, meaning, and moral relevance can directly affect what we see. For example, under conditions of brief presentation, morally relevant words reportedly "pop out" and are easier to identify than morally irrelevant words. Though such results purport to show that perception itself is sensitive to such factors, much of this research instead demonstrates effects on visual recognition--which necessarily involves not only visual processing per se, but also memory retrieval. Here we report three experiments which suggest that many alleged top-down effects of this sort are actually effects on 'back-end' memory rather than 'front-end' perception. In particular, the same methods used to demonstrate popout effects for supposedly privileged stimuli (such as morality-related words, e.g. "punishment" and "victim") also yield popout effects for unmotivated, superficial categories (such as fashion-related words, e.g. "pajamas" and "stiletto"). We conclude that such effects reduce to well-known memory processes (in this case, semantic priming) that do not involve morality, and have no implications for debates about whether higher-level factors influence perception. These case studies illustrate how it is critical to distinguish perception from memory in alleged 'top-down' effects. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. The Posture of Putting One's Palms Together Modulates Visual Motion Event Perception.

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    Saito, Godai; Gyoba, Jiro

    2018-02-01

    We investigated the effect of an observer's hand postures on visual motion perception using the stream/bounce display. When two identical visual objects move across collinear horizontal trajectories toward each other in a two-dimensional display, observers perceive them as either streaming or bouncing. In our previous study, we found that when observers put their palms together just below the coincidence point of the two objects, the percentage of bouncing responses increased, mainly depending on the proprioceptive information from their own hands. However, it remains unclear if the tactile or haptic (force) information produced by the postures mostly influences the stream/bounce perception. We solved this problem by changing the tactile and haptic information on the palms of the hands. Experiment 1 showed that the promotion of bouncing perception was observed only when the posture of directly putting one's palms together was used, while there was no effect when a brick was sandwiched between the participant's palms. Experiment 2 demonstrated that the strength of force used when putting the palms together had no effect on increasing bounce perception. Our findings indicate that the hands-induced bounce effect derives from the tactile information produced by the direct contact between both palms.

  16. The impact of art integration as an intervention to assist learners' visual perception and concept understanding in elementary science

    Science.gov (United States)

    Smilan, Cathy A.

    Art integration as educational reform has been the focus of recent debate. The suggestion has been made that the arts can provide unique learning opportunities in other content areas. To provide empirical evidence for this added value of the arts in learning, this study investigated the efficacy of teaching science concepts in and through the visual arts by implementing an art integrated lesson. The study investigated the impact of an art integration to assist elementary level learners' visual perception so they could more accurately form mental models of the science ideas. The hypothesis suggests that participants in the art intervention who construct a three-dimensional representation of abstract science concepts will gain an increased understanding of those concepts. Specifically, students who work with parallel concepts in art and science to make and manipulate three-dimensional, kinetic models of the sun, earth, and moon will be able to more accurately visualize the relationships between these heavenly bodies. Fifth grade students participated in the study which was integrated into the regular curriculum. Seventy-six randomly selected students comprised the experimental group and participated in the art project. After the completion of traditional textbook and lecture presentation by the classroom teachers, a researcher developed Science Concept Test was administered to all fifth grade students. Statistically significant results indicated that the differences between the groups on the science concept test were due to the integration of the art intervention. These empirical data show significant differences between the group receiving the art intervention and the group receiving traditional classroom instruction, supporting the efficacy of the art integration model. In conclusion, the study supports the literature that suggests the efficacy of art integration partnerships as alternative avenues for presenting and representing knowledge. The study additionally

  17. Shadows of artistry: cortical synchrony during perception and imagery of visual art.

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    Bhattacharya, Joydeep; Petsche, Hellmuth

    2002-04-01

    Functional and topographical differences between two groups, artists and non-artists, during the performances of visual perception and imagery of paintings were presented by means of EEG phase synchrony analysis. In artists as compared with non-artists, significantly higher phase synchrony was found in the high frequency beta and gamma bands during the perception of the paintings; in the low frequency bands (primarily delta), phase synchrony was mostly enhanced during imagery. Strong decreases in phase synchrony of alpha were found primarily in artists for both tasks. The right hemisphere was found to present higher synchrony than the left in artists, whereas hemispheric asymmetry was less significant in non-artists. In the artists, enhanced synchrony in the high frequency band is most likely due to their enhanced binding capabilities of numerous visual attributes, and enhanced synchrony in the low frequency band seems to be due to the higher involvement of long-term visual memory mostly in imagery. Thus, the analysis of phase synchrony from EEG signals yields new information about the dynamical co-operation between neuronal assemblies during the cognition of visual art. Copyright 2002 Elsevier Science B.V.

  18. The spatially asymmetric cost of memory load on visual perception: transient stimulus-centered neglect.

    Science.gov (United States)

    Gozli, Davood G; Wilson, Kristin E; Ferber, Susanne

    2014-04-01

    Recent evidence suggests that visual working memory (VWM) load reduces performance accuracy on a concurrent visual recognition task, particularly for objects presented in the left hemifield. It has also been shown that high VWM load causes suppression of activity in the right temporoparietal junction (TPJ). Given the resemblance of VWM load effects to symptoms of unilateral neglect (i.e., impaired perception on the left side and lesion to the right TPJ), we investigated whether VWM load effects are restricted to the left side of space or extend to object-centered reference frames. In other words, akin to object-centered neglect, can high VWM load cause a perceptual cost in attending to the left side of the stimulus? We addressed this question using an object recognition task (Experiment 1) and a visual search task (Experiment 2) showing that this transient left-neglect can indeed be modulated by an object-centered frame of reference. These findings suggest that load-induced impairments of visual attention are spatially asymmetric and can emerge within multiple spatial reference frames. Therefore, the attentional consequences of high VWM load on conscious perception may serve as a useful model of unilateral perceptual neglect.

  19. Human fMRI reveals that delayed action re-recruits visual perception.

    Directory of Open Access Journals (Sweden)

    Anthony Singhal

    Full Text Available Behavioral and neuropsychological research suggests that delayed actions rely on different neural substrates than immediate actions; however, the specific brain areas implicated in the two types of actions remain unknown. We used functional magnetic resonance imaging (fMRI to measure human brain activation during delayed grasping and reaching. Specifically, we examined activation during visual stimulation and action execution separated by a 18-s delay interval in which subjects had to remember an intended action toward the remembered object. The long delay interval enabled us to unambiguously distinguish visual, memory-related, and action responses. Most strikingly, we observed reactivation of the lateral occipital complex (LOC, a ventral-stream area implicated in visual object recognition, and early visual cortex (EVC at the time of action. Importantly this reactivation was observed even though participants remained in complete darkness with no visual stimulation at the time of the action. Moreover, within EVC, higher activation was observed for grasping than reaching during both vision and action execution. Areas in the dorsal visual stream were activated during action execution as expected and, for some, also during vision. Several areas, including the anterior intraparietal sulcus (aIPS, dorsal premotor cortex (PMd, primary motor cortex (M1 and the supplementary motor area (SMA, showed sustained activation during the delay phase. We propose that during delayed actions, dorsal-stream areas plan and maintain coarse action goals; however, at the time of execution, motor programming requires re-recruitment of detailed visual information about the object through reactivation of (1 ventral-stream areas involved in object perception and (2 early visual areas that contain richly detailed visual representations, particularly for grasping.

  20. Human fMRI reveals that delayed action re-recruits visual perception.

    Science.gov (United States)

    Singhal, Anthony; Monaco, Simona; Kaufman, Liam D; Culham, Jody C

    2013-01-01

    Behavioral and neuropsychological research suggests that delayed actions rely on different neural substrates than immediate actions; however, the specific brain areas implicated in the two types of actions remain unknown. We used functional magnetic resonance imaging (fMRI) to measure human brain activation during delayed grasping and reaching. Specifically, we examined activation during visual stimulation and action execution separated by a 18-s delay interval in which subjects had to remember an intended action toward the remembered object. The long delay interval enabled us to unambiguously distinguish visual, memory-related, and action responses. Most strikingly, we observed reactivation of the lateral occipital complex (LOC), a ventral-stream area implicated in visual object recognition, and early visual cortex (EVC) at the time of action. Importantly this reactivation was observed even though participants remained in complete darkness with no visual stimulation at the time of the action. Moreover, within EVC, higher activation was observed for grasping than reaching during both vision and action execution. Areas in the dorsal visual stream were activated during action execution as expected and, for some, also during vision. Several areas, including the anterior intraparietal sulcus (aIPS), dorsal premotor cortex (PMd), primary motor cortex (M1) and the supplementary motor area (SMA), showed sustained activation during the delay phase. We propose that during delayed actions, dorsal-stream areas plan and maintain coarse action goals; however, at the time of execution, motor programming requires re-recruitment of detailed visual information about the object through reactivation of (1) ventral-stream areas involved in object perception and (2) early visual areas that contain richly detailed visual representations, particularly for grasping.

  1. Visual anticipation biases conscious perception but not bottom-up visual processing

    Directory of Open Access Journals (Sweden)

    Paul F.M.J. Verschure

    2015-01-01

    Full Text Available Theories of consciousness can be grouped with respect to their stance on embodiment, sensori-motor contingencies, prediction and integration. In this list prediction plays a key role and it is not clear which aspects of prediction are most prominent in the conscious scene. An evolving view on the brain is that it can be seen as a prediction machine that optimizes its ability to predict states of the world and the self through the top-down propagation of predictions and the bottom-up presentation of prediction errors. There are competing views though on whether prediction or prediction errors dominate the conscious scene. Yet, due to the lack of efficient indirect measures, the dynamic effects of prediction on perception, decision making and consciousness have been difficult to assess and to model. We propose a novel mathematical framework and psychophysical paradigm that allows us to assess both the hierarchical structuring of perceptual consciousness, its content and the impact of predictions and / or errors on the conscious scene. Using a displacement detection task combined with reverse correlation we reveal signatures of the usage of prediction at three different levels of perception: bottom-up early saccades, top-down driven late saccades and conscious decisions. Our results suggest that the brain employs multiple parallel mechanisms at different levels of information processing to restrict the sensory field using predictions. We observe that cognitive load has a quantifiable effect on this dissociation of the bottom-up sensory and top-down predictive processes. We propose a probabilistic data association model from dynamical systems theory to model this predictive bias in different information processing levels.

  2. Real and visually-induced body inclination differently affect the perception of object stability.

    Directory of Open Access Journals (Sweden)

    Rafael Laboissière

    Full Text Available The prediction of object stability on earth requires the establishment of a perceptual frame of reference based on the direction of gravity. Across three experiments, we measured the critical angle (CA at which an object appeared equally likely to fall over or right itself. We investigated whether the internal representation of the gravity direction, biased by either simulated tilt (rotating visual surround or real body tilt situations, influences in a similar fashion the judgment of stability. In the simulated tilt condition, the estimated CA and the perceived gravity are both deviated in the same direction. In the real tilt condition, the orientation of the body affects the perception of gravity direction but has no effect on the estimated CA. Results suggest that people differently weigh gravity direction information provided by visual motion and by visual polarity cues for estimating the stability of objects.

  3. Perception of Complete Visually Impaired Children to Three Different Oral Health Education Methods: A Preliminary Study.

    Science.gov (United States)

    Mudunuri, S; Sharma, A; Subramaniam, P

    To evaluate the perception of visually impaired children to three different methods of oral health education. Sixty total visually impaired children were divided into three groups of 20 children each. Children in group-I received oral health education through a lecture. Children in group II received Demonstration on a Model by Tell and Touch method (DMTT) and children in group III were self trained on oral hygiene skills. All children received written instructions in Braille. Their knowledge and practice of oral hygiene methods were recorded by a questionnaire and their method of brushing and rinsing was assessed during a personal interview. Data obtained was subjected to statistical analysis. Children in group II were able to brush and rinse significantly better (p visually impaired children.

  4. Comparison between visual grading and planimetric quantification of microvascular obstruction extent assessment in reperfused acute myocardial infarction.

    Science.gov (United States)

    Sirol, Marc; Gzara, Heger; Gayat, Etienne; Dautry, Raphael; Gellen, Barnabas; Logeart, Damien; Soyer, Philippe; Vicaut, Eric; Mercadier, Jean-Jacques

    2016-07-01

    Current methods for infarct size and microvascular obstruction (MVO) quantification by cardiac magnetic resonance (CMR) imaging rely on planimetry. This method is time-consuming. We sought to evaluate a direct assessment of MVO severity based on visual evaluation and to compare it to a reference method. CMR was performed in 112 consecutive patients after reperfused myocardial infarction. MVO was estimated by direct visual assessment based on a three-grade severity scale (MVO 1, mild; MVO 2, moderate; MVO 3, severe) on late gadolinium-enhancement (LGE). MVO was present in 69 patients (61.6 %). Quantitative MVO extent significantly increased accordingly to visual MVO grading (p < 0.01). Correlation between visual grading and quantitative assessment was excellent (r = 0.92, IQR 0.88-0.95, p < 0.001). CMR inter- and intraobserver variability for visual MVO evaluation was low (κ = 0.93 and κ = 0.96, respectively), whereas quantitative MVO assessment suffered from moderate agreement (interobserver, bias = -0.81 ± 1.8 g LV; intraobserver, -0.83 ± 2.1 g LV). Visual evaluation was significantly faster than reference method (0.65 ± 0.37 vs. 10.2 ± 2.9 min, p < 0.0001). MVO severity based on direct visual assessment on LGE images is feasible, rapid, reproducible and agrees very well with quantitative methods, with a very low inter- and intraobserver variability. Our approach could be used for routine evaluation in patients undergoing CMR after acute myocardial infarction. • Microvascular obstruction direct visual evaluation is feasible, rapid and highly reproducible. • Microvascular obstruction direct visual evaluation correlates well with quantification by planimetry. • Microvascular obstruction or no-reflow phenomenon is determined on late gadolinium-enhanced images. • Cardiac MRI is useful for myocardial damage assessment after myocardial infarction.

  5. Grade repetition and parents' perception of hearing loss: An analysis of data from children in the United States.

    Science.gov (United States)

    Gilani, Sapideh; Roditi, Rachel; Bhattacharyya, Neil

    2017-03-01

    To determine whether parent-perceived hearing problems are associated with grade repetition among children in the United States. Retrospective cohort analysis of a contemporary national database. The National Survey of Children's Health 2011 to 2012 was analyzed. Hearing loss, as perceived and reported by parents, was categorized as: no hearing problem, history of a hearing problem, or current hearing problem. Children never repeating a grade versus repeating one or more grades (kindergarten-high school) were identified. Univariate statistics and multivariate logistic regression analyzed the association of hearing problems with grade repetition. Patients with mental retardation, autism, and attention-deficit/hyperactivity disorder were excluded from the analysis. After adjusting for race, sex, and poverty level, odds ratios for grade repetition were computed. Among 66.1 million (average age, 8.3 years, 49.0% male) children, 97.3% never had a hearing problem, 1.7% had a history of a hearing problem, and 1.0% had a current hearing problem. Overall, 7.1% repeated a grade. Grade repetition was reported in 6.9% of children without a hearing problem versus 9.4% with a history of a hearing problem and 19.3% with a current hearing problem (P hearing problem demonstrated an odds ratio of 1.9 (95% confidence interval 0.82-4.13) for grade repetition, whereas a current hearing problem demonstrated an odds ratio of 3.0 (1.90-4.80). Parents' perception of children's hearing problems is strongly associated with grade repetition. This trend is noticed in elementary school more than in high school. 4. Laryngoscope, 127:741-745, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  6. Developmental Test of Visual-Motor Integration (VMI): An Effective Outcome Measure for Handwriting Interventions for Kindergarten, First-Grade, and Second-Grade Students?

    Science.gov (United States)

    Pfeiffer, Beth; Moskowitz, Beverly; Paoletti, Andrew; Brusilovskiy, Eugene; Zylstra, Sheryl Eckberg; Murray, Tammy

    2015-01-01

    We determined whether a widely used assessment of visual-motor skills, the Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI), is appropriate for use as an outcome measure for handwriting interventions. A two-group pretest-posttest design was used with 207 kindergarten, first-grade, and second-grade students. Two well-established handwriting measures and the VMI were administered pre- and postintervention. The intervention group participated in the Size Matters Handwriting Program for 40 sessions, and the control group received standard instruction. Paired and independent-samples t tests were used to analyze group differences. The intervention group demonstrated significant improvements on the handwriting measures, with change scores having mostly large effect sizes. We found no significant difference in change scores on the VMI, t(202)=1.19, p=.23. Results of this study suggest that the VMI may not detect changes in handwriting related to occupational therapy intervention. Copyright © 2015 by the American Occupational Therapy Association, Inc.

  7. Is there a correlation between students' perceptions of their middle school science classroom learning environment and their classroom grades?

    Science.gov (United States)

    Snyder, Wayne

    The purpose of this study was to determine if the marking period grades of middle school science students are correlated with their perception of the classroom learning environment, and if so could such an indicator be used in feedback loops for ongoing classroom learning environment evaluation and evolution. The study examined 24 classrooms in three districts representing several different types of districts and a diverse student population. The independent variable was the students' perceptions of their classroom learning environment (CLE). This variable was represented by their responses on the WIHIC (What Is Happening In This Class) questionnaire. The dependent variable was the students' marking period grades. Background data about the students was included, and for further elaboration and clarification, qualitative data was collected through student and teacher interviews. Middle school science students in this study perceived as most positive those domains over which they have more locus of control. Perceptions showed some variance by gender, ethnicity, teacher/district, and socio-economic status when viewing the absolute values of the domain variables. The patterns of the results show consistency between groups. Direct correlation between questionnaire responses and student grades was not found to be significant except for a small significance with "Task Orientation". This unexpected lack of correlation may be explained by inconsistencies between grading schemes, inadequacies of the indicator instrument, and/or by the one-time administration of the variables. Analysis of the qualitative and quantitative data led to the conclusion that this instrument is picking up information, but that revisions in both the variables and in the process are needed. Grading schemes need to be decomposed, the instrument needs to be revised, and the process needs to be implemented as a series of regular feed-back loops.

  8. Environmental risk perception from visual cues: the psychophysics of tornado risk perception

    Science.gov (United States)

    Dewitt, Barry; Fischhoff, Baruch; Davis, Alexander; Broomell, Stephen B.

    2015-12-01

    Lay judgments of environmental risks are central to both immediate decisions (e.g., taking shelter from a storm) and long-term ones (e.g., building in locations subject to storm surges). Using methods from quantitative psychology, we provide a general approach to studying lay perceptions of environmental risks. As a first application of these methods, we investigate a setting where lay decisions have not taken full advantage of advances in natural science understanding: tornado forecasts in the US and Canada. Because official forecasts are imperfect, members of the public must often evaluate the risks on their own, by checking environmental cues (such as cloud formations) before deciding whether to take protective action. We study lay perceptions of cloud formations, demonstrating an approach that could be applied to other environmental judgments. We use signal detection theory to analyse how well people can distinguish tornadic from non-tornadic clouds, and multidimensional scaling to determine how people make these judgments. We find that participants (N = 400 recruited from Amazon Mechanical Turk) have heuristics that generally serve them well, helping participants to separate tornadic from non-tornadic clouds, but which also lead them to misjudge the tornado risk of certain cloud types. The signal detection task revealed confusion regarding shelf clouds, mammatus clouds, and clouds with upper- and mid-level tornadic features, which the multidimensional scaling task suggested was the result of participants focusing on the darkness of the weather scene and the ease of discerning its features. We recommend procedures for training (e.g., for storm spotters) and communications (e.g., tornado warnings) that will reduce systematic misclassifications of tornadicity arising from observers’ reliance on otherwise useful heuristics.

  9. Categorical Perception of Colour in the Left and Right Visual Field Is Verbally Mediated: Evidence from Korean

    Science.gov (United States)

    Roberson, Debi; Pak, Hyensou; Hanley, J. Richard

    2008-01-01

    In this study we demonstrate that Korean (but not English) speakers show Categorical perception (CP) on a visual search task for a boundary between two Korean colour categories that is not marked in English. These effects were observed regardless of whether target items were presented to the left or right visual field. Because this boundary is…

  10. Combining Strengths and Weaknesses in Visual Perception of Children with an Autism Spectrum Disorder: Perceptual Matching of Facial Expressions

    Science.gov (United States)

    Evers, Kris; Noens, Ilse; Steyaert, Jean; Wagemans, Johan

    2011-01-01

    Background: Children with an autism spectrum disorder (ASD) are known to have an atypical visual perception, with deficits in automatic Gestalt formation and an enhanced processing of visual details. In addition, they are sometimes found to have difficulties in emotion processing. Methods: In three experiments, we investigated whether 7-to-11-year…

  11. Visual tuning and metrical perception of realistic point-light dance movements.

    Science.gov (United States)

    Su, Yi-Huang

    2016-03-07

    Humans move to music spontaneously, and this sensorimotor coupling underlies musical rhythm perception. The present research proposed that, based on common action representation, different metrical levels as in auditory rhythms could emerge visually when observing structured dance movements. Participants watched a point-light figure performing basic steps of Swing dance cyclically in different tempi, whereby the trunk bounced vertically at every beat and the limbs moved laterally at every second beat, yielding two possible metrical periodicities. In Experiment 1, participants freely identified a tempo of the movement and tapped along. While some observers only tuned to the bounce and some only to the limbs, the majority tuned to one level or the other depending on the movement tempo, which was also associated with individuals' preferred tempo. In Experiment 2, participants reproduced the tempo of leg movements by four regular taps, and showed a slower perceived leg tempo with than without the trunk bouncing simultaneously in the stimuli. This mirrors previous findings of an auditory 'subdivision effect', suggesting the leg movements were perceived as beat while the bounce as subdivisions. Together these results support visual metrical perception of dance movements, which may employ similar action-based mechanisms to those underpinning auditory rhythm perception.

  12. Audio-visual speech perception in adult readers with dyslexia: an fMRI study.

    Science.gov (United States)

    Rüsseler, Jascha; Ye, Zheng; Gerth, Ivonne; Szycik, Gregor R; Münte, Thomas F

    2018-04-01

    Developmental dyslexia is a specific deficit in reading and spelling that often persists into adulthood. In the present study, we used slow event-related fMRI and independent component analysis to identify brain networks involved in perception of audio-visual speech in a group of adult readers with dyslexia (RD) and a group of fluent readers (FR). Participants saw a video of a female speaker saying a disyllabic word. In the congruent condition, audio and video input were identical whereas in the incongruent condition, the two inputs differed. Participants had to respond to occasionally occurring animal names. The independent components analysis (ICA) identified several components that were differently modulated in FR and RD. Two of these components including fusiform gyrus and occipital gyrus showed less activation in RD compared to FR possibly indicating a deficit to extract face information that is needed to integrate auditory and visual information in natural speech perception. A further component centered on the superior temporal sulcus (STS) also exhibited less activation in RD compared to FR. This finding is corroborated in the univariate analysis that shows less activation in STS for RD compared to FR. These findings suggest a general impairment in recruitment of audiovisual processing areas in dyslexia during the perception of natural speech.

  13. Dissociation between the neural correlates of conscious face perception and visual attention.

    Science.gov (United States)

    Navajas, Joaquin; Nitka, Aleksander W; Quian Quiroga, Rodrigo

    2017-08-01

    Given the higher chance to recognize attended compared to unattended stimuli, the specific neural correlates of these two processes, attention and awareness, tend to be intermingled in experimental designs. In this study, we dissociated the neural correlates of conscious face perception from the effects of visual attention. To do this, we presented faces at the threshold of awareness and manipulated attention through the use of exogenous prestimulus cues. We show that the N170 component, a scalp EEG marker of face perception, was modulated independently by attention and by awareness. An earlier P1 component was not modulated by either of the two effects and a later P3 component was indicative of awareness but not of attention. These claims are supported by converging evidence from (a) modulations observed in the average evoked potentials, (b) correlations between neural and behavioral data at the single-subject level, and (c) single-trial analyses. Overall, our results show a clear dissociation between the neural substrates of attention and awareness. Based on these results, we argue that conscious face perception is triggered by a boost in face-selective cortical ensembles that can be modulated by, but are still independent from, visual attention. © 2017 Society for Psychophysiological Research.

  14. Visual tuning and metrical perception of realistic point-light dance movements

    Science.gov (United States)

    Su, Yi-Huang

    2016-01-01

    Humans move to music spontaneously, and this sensorimotor coupling underlies musical rhythm perception. The present research proposed that, based on common action representation, different metrical levels as in auditory rhythms could emerge visually when observing structured dance movements. Participants watched a point-light figure performing basic steps of Swing dance cyclically in different tempi, whereby the trunk bounced vertically at every beat and the limbs moved laterally at every second beat, yielding two possible metrical periodicities. In Experiment 1, participants freely identified a tempo of the movement and tapped along. While some observers only tuned to the bounce and some only to the limbs, the majority tuned to one level or the other depending on the movement tempo, which was also associated with individuals’ preferred tempo. In Experiment 2, participants reproduced the tempo of leg movements by four regular taps, and showed a slower perceived leg tempo with than without the trunk bouncing simultaneously in the stimuli. This mirrors previous findings of an auditory ‘subdivision effect’, suggesting the leg movements were perceived as beat while the bounce as subdivisions. Together these results support visual metrical perception of dance movements, which may employ similar action-based mechanisms to those underpinning auditory rhythm perception. PMID:26947252

  15. [Does music influence visual perception in campimetric measurements of the visual field?].

    Science.gov (United States)

    Gall, Carolin; Geier, Jens-Stefan; Sabel, Bernhard A; Kasten, Erich

    2009-01-01

    21 subjects (mean age 28,4 +/- 10,9, M +/- SD) without any damage of the visual system were examined with computer-based campimetric tests of near threshold stimulus detection whereby an artificial tunnel vision was induced. Campimetry was performed in four trials in randomized order using a within-subjects-design: 1. classical music, 2. Techno music, 3. music for relaxation and 4. no music. Results were slightly better in all music conditions. Performance was best when subjects were listening to Techno music. The average increase of correctly recognized stimuli and fixation controls amounted to 3 %. To check the stability of the effects 9 subjects were tested three times. A moderating influence of personality traits and habits of listening to music was tested but could not be found. We conclude that music has at least no negative influence on performance in the campimetric measurement. Reasons for the positive effects of music can be seen in a general increase of vigilance and a modulation of perceptual thresholds.

  16. Visual features for perception, attention, and working memory: Toward a three-factor framework.

    Science.gov (United States)

    Huang, Liqiang

    2015-12-01

    Visual features are the general building blocks for attention, perception, and working memory. Here, I explore the factors which can quantitatively predict all the differences they make in various paradigms. I tried to combine the strengths of experimental and correlational approaches in a novel way by developing an individual-item differences analysis to extract the factors from 16 stimulus types on the basis of their roles in eight tasks. A large sample size (410) ensured that all eight tasks had a reliability (Cronbach's α) of no less than 0.975, allowing the factors to be precisely determined. Three orthogonal factors were identified which correspond respectively to featural strength (i.e., how close a stimulus is to a basic feature), visual strength (i.e., visual quality of the stimulus), and spatial strength (i.e., how well a stimulus can be represented as a spatial structure). Featural strength helped substantially in all the tasks but moderately less so in perceptual discrimination; visual strength helped substantially in low-level tasks but not in high-level tasks; and spatial strength helped change detection but hindered ensemble matching and visual search. Jointly, these three factors explained 96.4% of all the variances of the eight tasks, making it clear that they account for almost everything about the roles of these 16 stimulus types in these eight tasks. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Neural associations of the early retinotopic cortex with the lateral occipital complex during visual perception.

    Directory of Open Access Journals (Sweden)

    Delong Zhang

    Full Text Available Previous studies have demonstrated that the early retinotopic cortex (ERC, i.e., V1/V2/V3 is highly associated with the lateral occipital complex (LOC during visual perception. However, it remains largely unclear how to evaluate their associations in quantitative way. The present study tried to apply a multivariate pattern analysis (MVPA to quantify the neural activity in ERC and its association with that of the LOC when participants saw visual images. To this end, we assessed whether low-level visual features (Gabor features could predict the neural activity in the ERC and LOC according to a voxel-based encoding model (VBEM, and then quantified the association of the neural activity between these regions by using an analogical VBEM. We found that the Gabor features remarkably predicted the activity of the ERC (e.g., the predicted accuracy was 52.5% for a participant instead of that of the LOC (4.2%. Moreover, the MVPA approach can also be used to establish corresponding relationships between the activity patterns in the LOC and those in the ERC (64.2%. In particular, we found that the integration of the Gabor features and LOC visual information could dramatically improve the 'prediction' of ERC activity (88.3%. Overall, the present study provides new evidences for the possibility of quantifying the association of the neural activity between the regions of ERC and LOC. This approach will help to provide further insights into the neural substrates of the visual processing.

  18. Depth cues in human visual perception and their realization in 3D displays

    Science.gov (United States)

    Reichelt, Stephan; Häussler, Ralf; Fütterer, Gerald; Leister, Norbert

    2010-04-01

    Over the last decade, various technologies for visualizing three-dimensional (3D) scenes on displays have been technologically demonstrated and refined, among them such of stereoscopic, multi-view, integral imaging, volumetric, or holographic type. Most of the current approaches utilize the conventional stereoscopic principle. But they all lack of their inherent conflict between vergence and accommodation since scene depth cannot be physically realized but only feigned by displaying two views of different perspective on a flat screen and delivering them to the corresponding left and right eye. This mismatch requires the viewer to override the physiologically coupled oculomotor processes of vergence and eye focus that may cause visual discomfort and fatigue. This paper discusses the depth cues in the human visual perception for both image quality and visual comfort of direct-view 3D displays. We concentrate our analysis especially on near-range depth cues, compare visual performance and depth-range capabilities of stereoscopic and holographic displays, and evaluate potential depth limitations of 3D displays from a physiological point of view.

  19. SoftAR: visually manipulating haptic softness perception in spatial augmented reality.

    Science.gov (United States)

    Punpongsanon, Parinya; Iwai, Daisuke; Sato, Kosuke

    2015-11-01

    We present SoftAR, a novel spatial augmented reality (AR) technique based on a pseudo-haptics mechanism that visually manipulates the sense of softness perceived by a user pushing a soft physical object. Considering the limitations of projection-based approaches that change only the surface appearance of a physical object, we propose two projection visual effects, i.e., surface deformation effect (SDE) and body appearance effect (BAE), on the basis of the observations of humans pushing physical objects. The SDE visualizes a two-dimensional deformation of the object surface with a controlled softness parameter, and BAE changes the color of the pushing hand. Through psychophysical experiments, we confirm that the SDE can manipulate softness perception such that the participant perceives significantly greater softness than the actual softness. Furthermore, fBAE, in which BAE is applied only for the finger area, significantly enhances manipulation of the perception of softness. We create a computational model that estimates perceived softness when SDE+fBAE is applied. We construct a prototype SoftAR system in which two application frameworks are implemented. The softness adjustment allows a user to adjust the softness parameter of a physical object, and the softness transfer allows the user to replace the softness with that of another object.

  20. Teachers’ Perception on Social Skills of Students with Visual Impairments and its Relation with Academic Achievements

    Directory of Open Access Journals (Sweden)

    Mohd Hafiz Baharom

    2017-03-01

    Full Text Available Social skills is one of the problems experienced by students with visual impairment due to the absence of visual perception. The aim of this study is to explore the level of social skills among students with visual impairment of teacher perception. This study also reviewed the level of academic achievement based on the result of Primary School Achievement Test (UPSR and it’s correlation with the social skills. This survey was conducted on 32 year six students with visual impairment from special education integration program and Special Education School for The Blind from seven states. The instrument was a set of questionnaires that were administered to the sample teachers. Data were analysed using descriptive statistics which involved mean and standard deviation as well as inferential analysis Spearman’s correlation coefficient. The findings showed that teacher’s perception towards social skills of students with visual impairment was high. However, this survey also found that their level of academic achievement was low. Spearman’s correlation coefficient inference analysis revealed, there are positive but very weak and insignificant correlation between social skills and academic achievement. In conclusion, this study show efforts must be made in order to improve the academic achievement of these groups. Kemahiran sosial adalah salah satu permasalahan yang dialami oleh Murid Berkeperluan Pendidikan Khas (MBK ketidakupayaan penglihatan akibat ketiadaan persepsi visual. Objektif kajian ini dijalankan adalah untuk meninjau tahap kemahiran sosial MBK ketidakupayaan penglihatan dari persepsi guru. Selain itu, kajian ini juga meninjau tahap pencapaian akademik MBK ketidakupayaan penglihatan melalui keputusan Ujian Pencapaian Sekolah Rendah (UPSR dan melihat hubungannya dengan kemahiran sosial murid. Sampel kajian terdiri daripada 32 orang MBK ketidakupayaan penglihatan tahun enam program pendidikan khas integrasi dan Sekolah Pendidikan Khas

  1. A dual systems account of visual perception: Predicting candy consumption from distance estimates.

    Science.gov (United States)

    Krpan, Dario; Schnall, Simone

    2017-04-01

    A substantial amount of evidence shows that visual perception is influenced by forces that control human actions, ranging from motivation to physiological potential. However, studies have not yet provided convincing evidence that perception itself is directly involved in everyday behaviors such as eating. We suggest that this issue can be resolved by employing the dual systems account of human behavior. We tested the link between perceived distance to candies and their consumption for participants who were tired or depleted (impulsive system), versus those who were not (reflective system). Perception predicted eating only when participants were tired (Experiment 1) or depleted (Experiments 2 and 3). In contrast, a rational determinant of behavior-eating restraint towards candies-predicted eating for non-depleted individuals (Experiment 2). Finally, Experiment 3 established that perceived distance was correlated with participants' self-reported motivation to consume candies. Overall, these findings suggest that the dynamics between perception and behavior depend on the interplay of the two behavioral systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. A Rotational Motion Perception Neural Network Based on Asymmetric Spatiotemporal Visual Information Processing.

    Science.gov (United States)

    Hu, Bin; Yue, Shigang; Zhang, Zhuhong

    All complex motion patterns can be decomposed into several elements, including translation, expansion/contraction, and rotational motion. In biological vision systems, scientists have found that specific types of visual neurons have specific preferences to each of the three motion elements. There are computational models on translation and expansion/contraction perceptions; however, little has been done in the past to create computational models for rotational motion perception. To fill this gap, we proposed a neural network that utilizes a specific spatiotemporal arrangement of asymmetric lateral inhibited direction selective neural networks (DSNNs) for rotational motion perception. The proposed neural network consists of two parts-presynaptic and postsynaptic parts. In the presynaptic part, there are a number of lateral inhibited DSNNs to extract directional visual cues. In the postsynaptic part, similar to the arrangement of the directional columns in the cerebral cortex, these direction selective neurons are arranged in a cyclic order to perceive rotational motion cues. In the postsynaptic network, the delayed excitation from each direction selective neuron is multiplied by the gathered excitation from this neuron and its unilateral counterparts depending on which rotation, clockwise (cw) or counter-cw (ccw), to perceive. Systematic experiments under various conditions and settings have been carried out and validated the robustness and reliability of the proposed neural network in detecting cw or ccw rotational motion. This research is a critical step further toward dynamic visual information processing.All complex motion patterns can be decomposed into several elements, including translation, expansion/contraction, and rotational motion. In biological vision systems, scientists have found that specific types of visual neurons have specific preferences to each of the three motion elements. There are computational models on translation and expansion

  3. Picture yourself at the polls: visual perspective in mental imagery affects self-perception and behavior.

    Science.gov (United States)

    Libby, Lisa K; Shaeffer, Eric M; Eibach, Richard P; Slemmer, Jonathan A

    2007-03-01

    The present research demonstrates that the visual perspective--own first-person versus observer's third-person--people use to picture themselves engaging in a potential future action affects their self-perceptions and subsequent behavior. On the eve of the 2004 U.S. presidential election, registered voters in Ohio were instructed to use either the first-person or the third-person perspective to picture themselves voting in the election. Picturing voting from the third-person perspective caused subjects to adopt a stronger pro-voting mind-set correspondent with the imagined behavior. Further, this effect on self-perception carried over to behavior, causing subjects who were instructed to picture voting from the third-person perspective to be significantly more likely to vote in the election. These findings extend previous research in autobiographical memory and social judgment linking the observer's perspective with dispositional attributions, and demonstrate the causal role of imagery in determining future behavior.

  4. Multisensory Rehabilitation Training Improves Spatial Perception in Totally but Not Partially Visually Deprived Children

    Directory of Open Access Journals (Sweden)

    Giulia Cappagli

    2017-10-01

    Full Text Available Since it has been shown that spatial development can be delayed in blind children, focused sensorimotor trainings that associate auditory and motor information might be used to prevent the risk of spatial-related developmental delays or impairments from an early age. With this aim, we proposed a new technological device based on the implicit link between action and perception: ABBI (Audio Bracelet for Blind Interaction is an audio bracelet that produces a sound when a movement occurs by allowing the substitution of the visuo-motor association with a new audio-motor association. In this study, we assessed the effects of an extensive but entertaining sensorimotor training with ABBI on the development of spatial hearing in a group of seven 3–5 years old children with congenital blindness (n = 2; light perception or no perception of light or low vision (n = 5; visual acuity range 1.1–1.7 LogMAR. The training required the participants to play several spatial games individually and/or together with the psychomotor therapist 1 h per week for 3 months: the spatial games consisted of exercises meant to train their ability to associate visual and motor-related signals from their body, in order to foster the development of multisensory processes. We measured spatial performance by asking participants to indicate the position of one single fixed (static condition or moving (dynamic condition sound source on a vertical sensorized surface. We found that spatial performance of congenitally blind but not low vision children is improved after the training, indicating that early interventions with the use of science-driven devices based on multisensory capabilities can provide consistent advancements in therapeutic interventions, improving the quality of life of children with visual disability.

  5. Early Visual Perception Potentiated by Object Affordances: Evidence From a Temporal Order Judgment Task.

    Science.gov (United States)

    Ariga, Atsunori; Yamada, Yuki; Yamani, Yusuke

    2016-01-01

    Perceived objects automatically potentiate afforded action. Object affordances also facilitate perception of such objects, and this occurrence is known as the affordance effect. This study examined whether object affordances facilitate the initial visual processing stage, or perceptual entry processes, using the temporal order judgment task. The onset of the graspable (right-handled) coffee cup was perceived earlier than that of the less graspable (left-handled) cup for right-handed participants. The affordance effect was eliminated when the coffee cups were inverted, which presumably conveyed less affordance information. These results suggest that objects preattentively potentiate the perceptual entry processes in response to their affordances.

  6. Adult age differences in visual search from perception to response: Evidence from event-related potentials

    DEFF Research Database (Denmark)

    Wiegand, Iris

    Attentional changes play a major role in age-related behavioral slowing, however, the specific aspects of attention that contribute to this decrement are not clearly defined. To these aims, we combined response times with lateralized ERPs of younger and older adults during a visual compound search...... at multiple stages from perception to response. Furthermore, we explored the implicit influence of recently encountered information in terms of intertrial effects. ERPs could disentangle that, while automatic processes of perceptual-dimension priming and response priming across trials were preserved, older...

  7. Neuronal integration in visual cortex elevates face category tuning to conscious face perception.

    Science.gov (United States)

    Fahrenfort, Johannes J; Snijders, Tineke M; Heinen, Klaartje; van Gaal, Simon; Scholte, H Steven; Lamme, Victor A F

    2012-12-26

    The human brain has the extraordinary capability to transform cluttered sensory input into distinct object representations. For example, it is able to rapidly and seemingly without effort detect object categories in complex natural scenes. Surprisingly, category tuning is not sufficient to achieve conscious recognition of objects. What neural process beyond category extraction might elevate neural representations to the level where objects are consciously perceived? Here we show that visible and invisible faces produce similar category-selective responses in the ventral visual cortex. The pattern of neural activity evoked by visible faces could be used to decode the presence of invisible faces and vice versa. However, only visible faces caused extensive response enhancements and changes in neural oscillatory synchronization, as well as increased functional connectivity between higher and lower visual areas. We conclude that conscious face perception is more tightly linked to neural processes of sustained information integration and binding than to processes accommodating face category tuning.

  8. Simulating Visual Pattern Detection and Brightness Perception Based on Implicit Masking

    Directory of Open Access Journals (Sweden)

    Yang Jian

    2007-01-01

    Full Text Available A quantitative model of implicit masking, with a front-end low-pass filter, a retinal local compressive nonlinearity described by a modified Naka-Rushton equation, a cortical representation of the image in the Fourier domain, and a frequency-dependent compressive nonlinearity, was developed to simulate visual image processing. The model algorithm was used to estimate contrast sensitivity functions over 7 mean illuminance levels ranging from 0.0009 to 900 trolands, and fit to the contrast thresholds of 43 spatial patterns in the Modelfest study. The RMS errors between model estimations and experimental data in the literature were about 0.1 log unit. In addition, the same model was used to simulate the effects of simultaneous contrast, assimilation, and crispening. The model results matched the visual percepts qualitatively, showing the value of integrating the three diverse perceptual phenomena under a common theoretical framework.

  9. The Impact of Individual Ability, Favorable Team Member Scores, and Student Perception of Course Importance on Student Preference of Team-Based Learning and Grading Methods

    Science.gov (United States)

    Su, Allan Yen-Lun

    2007-01-01

    This study explores the impact of individual ability and favorable team member scores on student preference of team-based learning and grading methods, and examines the moderating effects of student perception of course importance on student preference of team-based learning and grading methods. The author also investigates the relationship…

  10. Visual And Performing Arts Framework For California Public Schools: Kindergarten through Grade Twelve

    Science.gov (United States)

    California State Department of Education, 2004

    2004-01-01

    This framework is designed to help classroom teachers and other educators develop curriculum and instruction in the arts so that all students will meet or exceed the content standards in dance, music, theatre, and the visual arts. In chapter 1, the framework presents guiding principles for instruction in dance, music, theatre, and the visual arts.…

  11. Historical perspective on the use of visual grading scales in evaluating skin irritation and sensitization

    DEFF Research Database (Denmark)

    Farage, Miranda A; Maibach, Howard I; Andersen, Klaus Ejner

    2011-01-01

    quality in comparison with current testing methods that rely on visual assessment. In addition, such measuring techniques can add considerably to the complexity of testing protocols. When benefits and cost are weighed in the balance, the visual assessment scales popularized by Draize and others remain...

  12. Which technology to investigate visual perception in sport: video vs. virtual reality.

    Science.gov (United States)

    Vignais, Nicolas; Kulpa, Richard; Brault, Sébastien; Presse, Damien; Bideau, Benoit

    2015-02-01

    Visual information uptake is a fundamental element of sports involving interceptive tasks. Several methodologies, like video and methods based on virtual environments, are currently employed to analyze visual perception during sport situations. Both techniques have advantages and drawbacks. The goal of this study is to determine which of these technologies may be preferentially used to analyze visual information uptake during a sport situation. To this aim, we compared a handball goalkeeper's performance using two standardized methodologies: video clip and virtual environment. We examined this performance for two response tasks: an uncoupled task (goalkeepers show where the ball ends) and a coupled task (goalkeepers try to intercept the virtual ball). Variables investigated in this study were percentage of correct zones, percentage of correct responses, radial error and response time. The results showed that handball goalkeepers were more effective, more accurate and started to intercept earlier when facing a virtual handball thrower than when facing the video clip. These findings suggested that the analysis of visual information uptake for handball goalkeepers was better performed by using a 'virtual reality'-based methodology. Technical and methodological aspects of these findings are discussed further. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Visual perception and appraisal of persons with impairments: a randomised controlled field experiment using photo elicitation.

    Science.gov (United States)

    Reinhardt, Jan Dietrich; Ballert, Carolina Saskia; Fellinghauer, Bernd; Lötscher, Alexander; Gradinger, Felix; Hilfiker, Roger; Graf, Sibylle; Stucki, Gerold

    2011-01-01

    Visual cues from persons with impairments may trigger stereotypical generalisations that lead to prejudice and discrimination. The main objective of this pilot study is to examine whether visual stimuli of impairment activate latent prejudice against disability and whether this connection can be counteracted with priming strategies. In a field experiment, participants were asked to rate photographs showing models with mental impairments, wheelchair users with paraplegia, and persons without any visible impairment. Participants should appraise the models with regard to several features (e.g. communicativeness, intelligence). One hundred participants rated 12 photo models yielding a total of 1183 observations. One group of participants was primed with a cover story introducing visual perception of impairment as the study's gist, while controls received neutral information. Photo models with mental impairments were rated lowest and models without visible impairment highest. In participants who did not have prior contacts with persons with impairments, priming led to a levelling of scores of models with and without impairment. Prior contacts with persons with impairments created similar effects as the priming. Unexpectedly, a pattern of converse double discrimination to the disadvantage of men with mental impairments was revealed. Signs of stereotypical processing of visual cues of impairment have been found in participants of the Swiss general population. Personal contact with persons with impairments as well as priming participants seems to reduce stereotyping.

  14. Real-time tracking using stereo and motion: Visual perception for space robotics

    Science.gov (United States)

    Nishihara, H. Keith; Thomas, Hans; Huber, Eric; Reid, C. Ann

    1994-01-01

    The state-of-the-art in computing technology is rapidly attaining the performance necessary to implement many early vision algorithms at real-time rates. This new capability is helping to accelerate progress in vision research by improving our ability to evaluate the performance of algorithms in dynamic environments. In particular, we are becoming much more aware of the relative stability of various visual measurements in the presence of camera motion and system noise. This new processing speed is also allowing us to raise our sights toward accomplishing much higher-level processing tasks, such as figure-ground separation and active object tracking, in real-time. This paper describes a methodology for using early visual measurements to accomplish higher-level tasks; it then presents an overview of the high-speed accelerators developed at Teleos to support early visual measurements. The final section describes the successful deployment of a real-time vision system to provide visual perception for the Extravehicular Activity Helper/Retriever robotic system in tests aboard NASA's KC135 reduced gravity aircraft.

  15. A Comparative Analysis of the Bender-Gestalt and Beery/Buktenica Tests of Visual-Motor Integration as a Function of Grade Level for Regular Education Students.

    Science.gov (United States)

    Lehman, Joanne; Breen, Michael J.

    1982-01-01

    Regular education students (N=125) in grades K-3 were administered the Bender-Gestalt and Beery/Buktenica tests of visual-motor integration. Found significant differences between the mean Bender and Beery age equivalent scores at each grade level. Discusses implications for their utilization in assessing fine motor readiness development.…

  16. Perception of linear horizontal self-motion induced by peripheral vision /linearvection/ - Basic characteristics and visual-vestibular interactions

    Science.gov (United States)

    Berthoz, A.; Pavard, B.; Young, L. R.

    1975-01-01

    The basic characteristics of the sensation of linear horizontal motion have been studied. Objective linear motion was induced by means of a moving cart. Visually induced linear motion perception (linearvection) was obtained by projection of moving images at the periphery of the visual field. Image velocity and luminance thresholds for the appearance of linearvection have been measured and are in the range of those for image motion detection (without sensation of self motion) by the visual system. Latencies of onset are around 1 sec and short term adaptation has been shown. The dynamic range of the visual analyzer as judged by frequency analysis is lower than the vestibular analyzer. Conflicting situations in which visual cues contradict vestibular and other proprioceptive cues show, in the case of linearvection a dominance of vision which supports the idea of an essential although not independent role of vision in self motion perception.

  17. The effect of combined sensory and semantic components on audio-visual speech perception in older adults.

    Science.gov (United States)

    Maguinness, Corrina; Setti, Annalisa; Burke, Kate E; Kenny, Rose Anne; Newell, Fiona N

    2011-01-01

    Previous studies have found that perception in older people benefits from multisensory over unisensory information. As normal speech recognition is affected by both the auditory input and the visual lip movements of the speaker, we investigated the efficiency of audio and visual integration in an older population by manipulating the relative reliability of the auditory and visual information in speech. We also investigated the role of the semantic context of the sentence to assess whether audio-visual integration is affected by top-down semantic processing. We presented participants with audio-visual sentences in which the visual component was either blurred or not blurred. We found that there was a greater cost in recall performance for semantically meaningless speech in the audio-visual 'blur' compared to audio-visual 'no blur' condition and this effect was specific to the older group. Our findings have implications for understanding how aging affects efficient multisensory integration for the perception of speech and suggests that multisensory inputs may benefit speech perception in older adults when the semantic content of the speech is unpredictable.

  18. The effect of combined sensory and semantic components on audio-visual speech perception in older adults

    Directory of Open Access Journals (Sweden)

    Corrina eMaguinness

    2011-12-01

    Full Text Available Previous studies have found that perception in older people benefits from multisensory over uni-sensory information. As normal speech recognition is affected by both the auditory input and the visual lip-movements of the speaker, we investigated the efficiency of audio and visual integration in an older population by manipulating the relative reliability of the auditory and visual information in speech. We also investigated the role of the semantic context of the sentence to assess whether audio-visual integration is affected by top-down semantic processing. We presented participants with audio-visual sentences in which the visual component was either blurred or not blurred. We found that there was a greater cost in recall performance for semantically meaningless speech in the audio-visual blur compared to audio-visual no blur condition and this effect was specific to the older group. Our findings have implications for understanding how aging affects efficient multisensory integration for the perception of speech and suggests that multisensory inputs may benefit speech perception in older adults when the semantic content of the speech is unpredictable.

  19. Perception of audio-visual speech synchrony in Spanish-speaking children with and without specific language impairment.

    Science.gov (United States)

    Pons, Ferran; Andreu, Llorenç; Sanz-Torrent, Monica; Buil-Legaz, Lucía; Lewkowicz, David J

    2013-06-01

    Speech perception involves the integration of auditory and visual articulatory information, and thus requires the perception of temporal synchrony between this information. There is evidence that children with specific language impairment (SLI) have difficulty with auditory speech perception but it is not known if this is also true for the integration of auditory and visual speech. Twenty Spanish-speaking children with SLI, twenty typically developing age-matched Spanish-speaking children, and twenty Spanish-speaking children matched for MLU-w participated in an eye-tracking study to investigate the perception of audiovisual speech synchrony. Results revealed that children with typical language development perceived an audiovisual asynchrony of 666 ms regardless of whether the auditory or visual speech attribute led the other one. Children with SLI only detected the 666 ms asynchrony when the auditory component preceded [corrected] the visual component. None of the groups perceived an audiovisual asynchrony of 366 ms. These results suggest that the difficulty of speech processing by children with SLI would also involve difficulties in integrating auditory and visual aspects of speech perception.

  20. Correction of Visual Perception Based on Neuro-Fuzzy Learning for the Humanoid Robot TEO.

    Science.gov (United States)

    Hernandez-Vicen, Juan; Martinez, Santiago; Garcia-Haro, Juan Miguel; Balaguer, Carlos

    2018-03-25

    New applications related to robotic manipulation or transportation tasks, with or without physical grasping, are continuously being developed. To perform these activities, the robot takes advantage of different kinds of perceptions. One of the key perceptions in robotics is vision. However, some problems related to image processing makes the application of visual information within robot control algorithms difficult. Camera-based systems have inherent errors that affect the quality and reliability of the information obtained. The need of correcting image distortion slows down image parameter computing, which decreases performance of control algorithms. In this paper, a new approach to correcting several sources of visual distortions on images in only one computing step is proposed. The goal of this system/algorithm is the computation of the tilt angle of an object transported by a robot, minimizing image inherent errors and increasing computing speed. After capturing the image, the computer system extracts the angle using a Fuzzy filter that corrects at the same time all possible distortions, obtaining the real angle in only one processing step. This filter has been developed by the means of Neuro-Fuzzy learning techniques, using datasets with information obtained from real experiments. In this way, the computing time has been decreased and the performance of the application has been improved. The resulting algorithm has been tried out experimentally in robot transportation tasks in the humanoid robot TEO (Task Environment Operator) from the University Carlos III of Madrid.

  1. Steady-state visually evoked potential correlates of human body perception.

    Science.gov (United States)

    Giabbiconi, Claire-Marie; Jurilj, Verena; Gruber, Thomas; Vocks, Silja

    2016-11-01

    In cognitive neuroscience, interest in the neuronal basis underlying the processing of human bodies is steadily increasing. Based on functional magnetic resonance imaging studies, it is assumed that the processing of pictures of human bodies is anchored in a network of specialized brain areas comprising the extrastriate and the fusiform body area (EBA, FBA). An alternative to examine the dynamics within these networks is electroencephalography, more specifically so-called steady-state visually evoked potentials (SSVEPs). In SSVEP tasks, a visual stimulus is presented repetitively at a predefined flickering rate and typically elicits a continuous oscillatory brain response at this frequency. This brain response is characterized by an excellent signal-to-noise ratio-a major advantage for source reconstructions. The main goal of present study was to demonstrate the feasibility of this method to study human body perception. To that end, we presented pictures of bodies and contrasted the resulting SSVEPs to two control conditions, i.e., non-objects and pictures of everyday objects (chairs). We found specific SSVEPs amplitude differences between bodies and both control conditions. Source reconstructions localized the SSVEP generators to a network of temporal, occipital and parietal areas. Interestingly, only body perception resulted in activity differences in middle temporal and lateral occipitotemporal areas, most likely reflecting the EBA/FBA.

  2. A Perception-Driven Approach to Supervised Dimensionality Reduction for Visualization.

    Science.gov (United States)

    Wang, Yunhai; Feng, Kang; Chu, Xiaowei; Zhang, Jian; Fu, Chi-Wing; Sedlmair, Michael; Yu, Xiaohui; Chen, Baoquan

    2017-05-05

    Dimensionality reduction (DR) is a common strategy for visual analysis of labeled high-dimensional data. Low-dimensional representations of the data help, for instance, to explore the class separability and the spatial distribution of the data. Widely-used unsupervised DR methods like PCA do not aim to maximize the class separation, while supervised DR methods like LDA often assume certain spatial distributions and do not take perceptual capabilities of humans into account. These issues make them ineffective for complicated class structures. Towards filling this gap, we present a perception-driven linear dimensionality reduction approach that maximizes the perceived class separation in projections. Our approach builds on recent developments in perception-based separation measures that have achieved good results in imitating human perception. We extend these measures to be density-aware and incorporate them into a customized simulated annealing algorithm, which can rapidly generate a near optimal DR projection. We demonstrate the effectiveness of our approach by comparing it to state-of-the-art DR methods on 93 datasets, using both quantitative measure and human judgments. We also provide case studies with class-imbalanced and unlabeled data.

  3. Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity.

    Directory of Open Access Journals (Sweden)

    Meredith S Berry

    Full Text Available Impulsivity in delay discounting is associated with maladaptive behaviors such as overeating and drug and alcohol abuse. Researchers have recently noted that delay discounting, even when measured by a brief laboratory task, may be the best predictor of human health related behaviors (e.g., exercise currently available. Identifying techniques to decrease impulsivity in delay discounting, therefore, could help improve decision-making on a global scale. Visual exposure to natural environments is one recent approach shown to decrease impulsive decision-making in a delay discounting task, although the mechanism driving this result is currently unknown. The present experiment was thus designed to evaluate not only whether visual exposure to natural (mountains, lakes relative to built (buildings, cities environments resulted in less impulsivity, but also whether this exposure influenced time perception. Participants were randomly assigned to either a natural environment condition or a built environment condition. Participants viewed photographs of either natural scenes or built scenes before and during a delay discounting task in which they made choices about receiving immediate or delayed hypothetical monetary outcomes. Participants also completed an interval bisection task in which natural or built stimuli were judged as relatively longer or shorter presentation durations. Following the delay discounting and interval bisection tasks, additional measures of time perception were administered, including how many minutes participants thought had passed during the session and a scale measurement of whether time "flew" or "dragged" during the session. Participants exposed to natural as opposed to built scenes were less impulsive and also reported longer subjective session times, although no differences across groups were revealed with the interval bisection task. These results are the first to suggest that decreased impulsivity from exposure to natural as

  4. Tornado Warning Perception and Response: Integrating the Roles of Visual Design, Demographics, and Hazard Experience.

    Science.gov (United States)

    Schumann, Ronald L; Ash, Kevin D; Bowser, Gregg C

    2018-02-01

    Recent advancements in severe weather detection and warning dissemination technologies have reduced, but not eliminated, large-casualty tornado hazards in the United States. Research on warning cognition and behavioral response by the public has the potential to further reduce tornado-related deaths and injuries; however, less research has been conducted in this area compared to tornado research in the physical sciences. Extant research in this vein tends to bifurcate. One branch of studies derives from classic risk perception, which investigates cognitive, affective, and sociocultural factors in relation to concern and preparation for uncertain risks. Another branch focuses on psychological, social, and cultural factors implicated in warning response for rapid onset hazards, with attention paid to previous experience and message design. Few studies link risk perceptions with cognition and response as elicited by specific examples of warnings. The present study unites risk perception, cognition, and response approaches by testing the contributions of hypothesized warning response drivers in one set of path models. Warning response is approximated by perceived fear and intended protective action as reported by survey respondents when exposed to hypothetical tornado warning scenarios. This study considers the roles of hazard knowledge acquisition, information-seeking behaviors, previous experience, and sociodemographic factors while controlling for the effects of the visual warning graphic. Findings from the study indicate the primacy of a user's visual interpretation of a warning graphic in shaping tornado warning response. Results also suggest that information-seeking habits, previous tornado experience, and local disaster culture play strong influencing roles in warning response. © 2017 Society for Risk Analysis.

  5. Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity.

    Science.gov (United States)

    Berry, Meredith S; Repke, Meredith A; Nickerson, Norma P; Conway, Lucian G; Odum, Amy L; Jordan, Kerry E

    2015-01-01

    Impulsivity in delay discounting is associated with maladaptive behaviors such as overeating and drug and alcohol abuse. Researchers have recently noted that delay discounting, even when measured by a brief laboratory task, may be the best predictor of human health related behaviors (e.g., exercise) currently available. Identifying techniques to decrease impulsivity in delay discounting, therefore, could help improve decision-making on a global scale. Visual exposure to natural environments is one recent approach shown to decrease impulsive decision-making in a delay discounting task, although the mechanism driving this result is currently unknown. The present experiment was thus designed to evaluate not only whether visual exposure to natural (mountains, lakes) relative to built (buildings, cities) environments resulted in less impulsivity, but also whether this exposure influenced time perception. Participants were randomly assigned to either a natural environment condition or a built environment condition. Participants viewed photographs of either natural scenes or built scenes before and during a delay discounting task in which they made choices about receiving immediate or delayed hypothetical monetary outcomes. Participants also completed an interval bisection task in which natural or built stimuli were judged as relatively longer or shorter presentation durations. Following the delay discounting and interval bisection tasks, additional measures of time perception were administered, including how many minutes participants thought had passed during the session and a scale measurement of whether time "flew" or "dragged" during the session. Participants exposed to natural as opposed to built scenes were less impulsive and also reported longer subjective session times, although no differences across groups were revealed with the interval bisection task. These results are the first to suggest that decreased impulsivity from exposure to natural as opposed to built

  6. Refractive error and visual functions in children with special needs compared with the first grade school students in oman.

    Science.gov (United States)

    Vora, Urmi; Khandekar, Rajiv; Natrajan, Sarvanan; Al-Hadrami, Khalfan

    2010-10-01

    We evaluated the refractive status and visual function of children with special needs (other handicap) in 2010 and compared them with healthy 1(st) grade school students in Oman. This was a cohort study. Optometrists recorded vision using a logarithm of minimum angle of resolution (LogMAR) chart. Preferential looking method was used for testing 31 children. Cycloplegic refraction was performed on all children. Contrast sensitivity was tested using 2.5%, 10%, and 100% contrast charts. Ocular movement, alignment, and anterior segment were also assessed. A pediatrician reviewed the health records of all the children at the time of their enrollment in this study to determine if the child had been diagnosed with a systemic condition or syndromes. The visual functions were assessed by study investigators. We estimated the rates and the risk of different visual function defects in children with special needs. The prevalence of refractive error in 70 children (4.7 ± 0.8 years) with special needs (group 1) and 175 normal healthy first grade students (group 2) were 58.5% and 2.9%, respectively. The risk of refractive error was significantly higher in children with special needs [relative risk, 48.1 (95% confidence interval, 17.54-131.8)]. Hyperopia (>1.00 D), myopia (≥ 1.00D) and astigmatism (≥ ±1.00 D) were found in 18.6%, 24.3%, and 27.1%, respectively, in group 1. Six children in this group had defective near vision. Sixteen (80%) children with Down syndrome had refractive error. Seven (50%) children with developmental disorder showed decreased contrast sensitivity. Prevalence of uncorrected refractive error was much higher in children with special needs. Prevalence of strabismus, nystagmus, and reduced contrast sensitivity was also higher in children with special needs. Early vision screening, visual function assessment, correction of refractive error, and frequent follow-up are recommended.

  7. Developing effective serious games: the effect of background sound on visual fidelity perception with varying texture resolution.

    Science.gov (United States)

    Rojas, David; Kapralos, Bill; Cristancho, Sayra; Collins, Karen; Hogue, Andrew; Conati, Cristina; Dubrowski, Adam

    2012-01-01

    Despite the benefits associated with virtual learning environments and serious games, there are open, fundamental issues regarding simulation fidelity and multi-modal cue interaction and their effect on immersion, transfer of knowledge, and retention. Here we describe the results of a study that examined the effect of ambient (background) sound on the perception of visual fidelity (defined with respect to texture resolution). Results suggest that the perception of visual fidelity is dependent on ambient sound and more specifically, white noise can have detrimental effects on our perception of high quality visuals. The results of this study will guide future studies that will ultimately aid in developing an understanding of the role that fidelity, and multi-modal interactions play with respect to knowledge transfer and retention for users of virtual simulations and serious games.

  8. Arousal Rules: An Empirical Investigation into the Aesthetic Experience of Cross-Modal Perception with Emotional Visual Music.

    Science.gov (United States)

    Lee, Irene Eunyoung; Latchoumane, Charles-Francois V; Jeong, Jaeseung

    2017-01-01

    Emotional visual music is a promising tool for the study of aesthetic perception in human psychology; however, the production of such stimuli and the mechanisms of auditory-visual emotion perception remain poorly understood. In Experiment 1, we suggested a literature-based, directive approach to emotional visual music design, and inspected the emotional meanings thereof using the self-rated psychometric and electroencephalographic (EEG) responses of the viewers. A two-dimensional (2D) approach to the assessment of emotion (the valence-arousal plane) with frontal alpha power asymmetry EEG (as a proposed index of valence) validated our visual music as an emotional stimulus. In Experiment 2, we used our synthetic stimuli to investigate possible underlying mechanisms of affective evaluation mechanisms in relation to audio and visual integration conditions between modalities (namely congruent, complementation, or incongruent combinations). In this experiment, we found that, when arousal information between auditory and visual modalities was contradictory [for example, active (+) on the audio channel but passive (-) on the video channel], the perceived emotion of cross-modal perception (visual music) followed the channel conveying the stronger arousal. Moreover, we found that an enhancement effect (heightened and compacted in subjects' emotional responses) in the aesthetic perception of visual music might occur when the two channels contained contradictory arousal information and positive congruency in valence and texture/control. To the best of our knowledge, this work is the first to propose a literature-based directive production of emotional visual music prototypes and the validations thereof for the study of cross-modally evoked aesthetic experiences in human subjects.

  9. Arousal Rules: An Empirical Investigation into the Aesthetic Experience of Cross-Modal Perception with Emotional Visual Music

    Science.gov (United States)

    Lee, Irene Eunyoung; Latchoumane, Charles-Francois V.; Jeong, Jaeseung

    2017-01-01

    Emotional visual music is a promising tool for the study of aesthetic perception in human psychology; however, the production of such stimuli and the mechanisms of auditory-visual emotion perception remain poorly understood. In Experiment 1, we suggested a literature-based, directive approach to emotional visual music design, and inspected the emotional meanings thereof using the self-rated psychometric and electroencephalographic (EEG) responses of the viewers. A two-dimensional (2D) approach to the assessment of emotion (the valence-arousal plane) with frontal alpha power asymmetry EEG (as a proposed index of valence) validated our visual music as an emotional stimulus. In Experiment 2, we used our synthetic stimuli to investigate possible underlying mechanisms of affective evaluation mechanisms in relation to audio and visual integration conditions between modalities (namely congruent, complementation, or incongruent combinations). In this experiment, we found that, when arousal information between auditory and visual modalities was contradictory [for example, active (+) on the audio channel but passive (−) on the video channel], the perceived emotion of cross-modal perception (visual music) followed the channel conveying the stronger arousal. Moreover, we found that an enhancement effect (heightened and compacted in subjects' emotional responses) in the aesthetic perception of visual music might occur when the two channels contained contradictory arousal information and positive congruency in valence and texture/control. To the best of our knowledge, this work is the first to propose a literature-based directive production of emotional visual music prototypes and the validations thereof for the study of cross-modally evoked aesthetic experiences in human subjects. PMID:28421007

  10. Auditory-visual speech integration by prelinguistic infants: perception of an emergent consonant in the McGurk effect.

    Science.gov (United States)

    Burnham, Denis; Dodd, Barbara

    2004-12-01

    The McGurk effect, in which auditory [ba] dubbed onto [ga] lip movements is perceived as "da" or "tha," was employed in a real-time task to investigate auditory-visual speech perception in prelingual infants. Experiments 1A and 1B established the validity of real-time dubbing for producing the effect. In Experiment 2, 4 1/2-month-olds were tested in a habituation-test paradigm, in which an auditory-visual stimulus was presented contingent upon visual fixation of a live face. The experimental group was habituated to a McGurk stimulus (auditory [ba] visual [ga]), and the control group to matching auditory-visual [ba]. Each group was then presented with three auditory-only test trials, [ba], [da], and [(delta)a] (as in then). Visual-fixation durations in test trials showed that the experimental group treated the emergent percept in the McGurk effect, [da] or [(delta)a], as familiar (even though they had not heard these sounds previously) and [ba] as novel. For control group infants [da] and [(delta)a] were no more familiar than [ba]. These results are consistent with infants' perception of the McGurk effect, and support the conclusion that prelinguistic infants integrate auditory and visual speech information. Copyright 2004 Wiley Periodicals, Inc.

  11. Effectiveness of Myocardial Contrast Echocardiography Quantitative Analysis during Adenosine Stress versus Visual Analysis before Percutaneous Therapy in Acute Coronary Pain: A Coronary Artery TIMI Grading Comparing Study

    Science.gov (United States)

    Yang, Lixia; Mu, Yuming; Quaglia, Luiz Augusto; Tang, Qi; Guan, Lina; Wang, Chunmei; Shih, Ming Chi

    2012-01-01

    The study aim was to compare two different stress echocardiography interpretation techniques based on the correlation with thrombosis in myocardial infarction (TIMI ) flow grading from acute coronary syndrome (ACS) patients. Forty-one patients with suspected ACS were studied before diagnostic coronary angiography with myocardial contrast echocardiography (MCE) at rest and at stress. The correlation of visual interpretation of MCE and TIMI flow grade was significant. The quantitative analysis (myocardial perfusion parameters: A, β, and A × β) and TIMI flow grade were significant. MCE visual interpretation and TIMI flow grade had a high degree of agreement, on diagnosing myocardial perfusion abnormality. If one considers TIMI flow grade <3 as abnormal, MCE visual interpretation at rest had 73.1% accuracy with 58.2% sensitivity and 84.2% specificity and at stress had 80.4% accuracy with 76.6% sensitivity and 83.3% specificity. The MCE quantitative analysis has better accuracy with 100% of agreement with different level of TIMI flow grading. MCE quantitative analysis at stress has showed a direct correlation with TIMI flow grade, more significant than the visual interpretation technique. Further studies could measure the clinical relevance of this more objective approach to managing acute coronary syndrome patient before percutaneous coronary intervention (PCI). PMID:22778555

  12. Dysfunctions of visual and auditory Gestalt perception (amusia) after stroke : Behavioral correlates and functional magnetic resonance imaging

    OpenAIRE

    Rosemann, Stephanie Heike

    2016-01-01

    Music is a special and unique part of human nature. Not only actively playing (making music in a group or alone) but also passive listening to music involves a richness of processes to make music the ideal tool to investigate how the human brain works. Acquired amusia denotes the impaired perception of melodies, rhythms, and the associated disability to enjoy music which can occur after a stroke. Many amusia patients also show deficits in visual perception, language, memory, and attention. He...

  13. Literacy through Photography: Multimodal and Visual Literacy in a Third Grade Classroom

    Science.gov (United States)

    Wiseman, Angela M.; Mäkinen, Marita; Kupiainen, Reijo

    2016-01-01

    This article reports findings from a diverse third grade classroom that integrates a literacy through photography (LTP) curriculum as a central component of writing instruction in an urban public school. A case study approach was used in order to provide an in-depth, multi-dimensional consideration of phenomena by drawing on multiple data sources…

  14. Impaired visual perception of hurtful actions in patients with chronic low back pain.

    Science.gov (United States)

    de Lussanet, Marc H E; Behrendt, Frank; Puta, Christian; Schulte, Tobias L; Lappe, Markus; Weiss, Thomas; Wagner, Heiko

    2013-10-01

    Visually presented biological motion stimuli activate regions in the brain that are also related to musculo-skeletal pain. We therefore hypothesized that chronic pain impairs the perception of visually presented actions that involve body parts that hurt. In the first experiment, chronic back pain (CLBP) patients and healthy controls judged the lifted weight from point-light biological motion displays. An actor either lifted an invisible container (5, 10, or 15 kg) from the floor, or lifted and manipulated it from the right to the left. The latter involved twisting of the lower back and would be very painful for CLBP patients. All participants recognized the displayed actions, but CLBP patients were impaired in judging the difference in handled weights, especially for the trunk rotation. The second experiment involved discrimination between forward and backward walking. Here the patients were just as good as the controls, showing that the main result of the first experiment was indeed specific to the sensory aspects of the task, and not to general impairments or attentional deficits. The results thus indicate that the judgment of sensorimotor aspects of a visually displayed movement is specifically affected by chronic low back pain. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Perception of visual texture and the expression of disruptive camouflage by the cuttlefish, Sepia officinalis

    Science.gov (United States)

    Kelman, E.J; Baddeley, R.J; Shohet, A.J; Osorio, D

    2007-01-01

    Juvenile cuttlefish (Sepia officinalis) camouflage themselves by changing their body pattern according to the background. This behaviour can be used to investigate visual perception in these molluscs and may also give insight into camouflage design. Edge detection is an important aspect of vision, and here we compare the body patterns that cuttlefish produced in response to checkerboard backgrounds with responses to backgrounds that have the same spatial frequency power spectrum as the checkerboards, but randomized spatial phase. For humans, phase randomization removes visual edges. To describe the cuttlefish body patterns, we scored the level of expression of 20 separate pattern ‘components’, and then derived principal components (PCs) from these scores. After varimax rotation, the first component (PC1) corresponded closely to the so-called disruptive body pattern, and the second (PC2) to the mottle pattern. PC1 was predominantly expressed on checkerboards, and PC2 on phase-randomized backgrounds. Thus, cuttlefish probably have edge detectors that control the expression of disruptive pattern. Although the experiments used unnatural backgrounds, it seems probable that cuttlefish display disruptive camouflage when there are edges in the visual background caused by discrete objects such as pebbles. We discuss the implications of these findings for our understanding of disruptive camouflage. PMID:17389219

  16. Subclinical alexithymia modulates early audio-visual perceptive and attentional event-related potentials.

    Science.gov (United States)

    Delle-Vigne, Dyna; Kornreich, Charles; Verbanck, Paul; Campanella, Salvatore

    2014-01-01

    Previous studies have highlighted the advantage of using audio-visual oddball tasks (instead of unimodal ones) in order to electrophysiologically index subclinical behavioral differences. Since alexithymia is highly prevalent in the general population, we investigated whether the use of various bimodal tasks could elicit emotional effects in low- vs. high-alexithymic scorers. Fifty students (33 females and 17 males) were split into groups based on low and high scores on the Toronto Alexithymia Scale (TAS-20). During event-related potential (ERP) recordings, they were exposed to three kinds of audio-visual oddball tasks: neutral-AVN-(geometrical forms and bips), animal-AVA-(dog and cock with their respective shouts), or emotional-AVE-(faces and voices) stimuli. In each condition, participants were asked to quickly detect deviant events occurring amongst a train of repeated and frequent matching stimuli (e.g., push a button when a sad face-voice pair appeared amongst a train of neutral face-voice pairs). P100, N100, and P300 components were analyzed: P100 refers to visual perceptive and attentional processing, N100 to auditory ones, and the P300 relates to response-related stages, involving memory processes. High-alexithymic scorers presented a particular pattern of results when processing the emotional stimulations, reflected in early ERP components by increased P100 and N100 amplitudes in the emotional oddball tasks [P100: F (2, 48) = 20,319, p stimuli.

  17. Using Japanese Onomatopoeias to Explore Perceptual Dimensions in Visual Material Perception.

    Science.gov (United States)

    Hanada, Mitsuhiko

    2016-01-28

    This study examined the perceptual dimensions of visual material properties. Photographs of 50 objects were presented to the participants, and they reported a suitable onomatopoeia (mimetic word) for describing the material of the object in each photograph, based on visual appearance. The participants' responses were collated into a contingency table of photographs × onomatopoeias. After removing some items from the table, correspondence analysis was applied to the contingency table, and a six-dimensional biplot was obtained. By rotating the axes to maximize sparseness of the coordinates for the items in the biplot, three meaningful perceptual dimensions were derived: wetness/stickiness, fluffiness/softness, and smoothness-roughness/gloss-dullness. Two additional possible dimensions were obtained: crumbliness and coldness. These dimensions, except gloss-dullness, were paid little attention to in vision science, though they were suggested as perceptual dimensions of tactile texture. This suggests that the perceptual dimensions that are considered to be primarily related to haptics are also important in visual material perception. © The Author(s) 2016.

  18. Primary visual cortex activity along the apparent-motion trace reflects illusory perception.

    Directory of Open Access Journals (Sweden)

    Lars Muckli

    2005-08-01

    Full Text Available The illusion of apparent motion can be induced when visual stimuli are successively presented at different locations. It has been shown in previous studies that motion-sensitive regions in extrastriate cortex are relevant for the processing of apparent motion, but it is unclear whether primary visual cortex (V1 is also involved in the representation of the illusory motion path. We investigated, in human subjects, apparent-motion-related activity in patches of V1 representing locations along the path of illusory stimulus motion using functional magnetic resonance imaging. Here we show that apparent motion caused a blood-oxygenation-level-dependent response along the V1 representations of the apparent-motion path, including regions that were not directly activated by the apparent-motion-inducing stimuli. This response was unaltered when participants had to perform an attention-demanding task that diverted their attention away from the stimulus. With a bistable motion quartet, we confirmed that the activity was related to the conscious perception of movement. Our data suggest that V1 is part of the network that represents the illusory path of apparent motion. The activation in V1 can be explained either by lateral interactions within V1 or by feedback mechanisms from higher visual areas, especially the motion-sensitive human MT/V5 complex.

  19. Probing the magnocellular and parvocellular visual pathways in facial emotion perception in schizophrenia.

    Science.gov (United States)

    Jahshan, Carol; Wolf, Maor; Karbi, Yinnon; Shamir, Eyal; Rassovsky, Yuri

    2017-07-01

    Schizophrenia patients have well-established deficits in facial emotion perception, which contribute to their poor social functioning. A number of studies have related these deficits to a differential dysfunction in the magnocellular (M) versus parvocellular (P) visual pathway. We assessed 35 schizophrenia patients and 35 healthy individuals on an emotion identification task, in which facial stimuli were either unaltered (broad spatial frequency, BSF) or manipulated to contain only high (HSF) or low (LSF) spatial frequencies, thereby respectively biasing the visual system toward the P- or M- pathways. As expected, patients were less accurate and slower in recognizing emotions across all conditions, relative to controls. Performance was best in the BSF condition followed by the HSF and finally the LSF condition, in both groups. A significant group by spatial frequency interaction reflected a smaller magnitude of impairment in the HSF condition, compared to the other two conditions that preferentially engage the M-system. These findings are consistent with studies showing a differential M-pathway abnormality in schizophrenia with a less pronounced impairment in P-function. The current study suggests that patients have less difficulty extracting emotional content from faces when LSFs are attenuated and supports the need to remediate basic visual processing deficits in schizophrenia. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  20. Age differences in visual-auditory self-motion perception during a simulated driving task

    Directory of Open Access Journals (Sweden)

    Robert eRamkhalawansingh

    2016-04-01

    Full Text Available Recent evidence suggests that visual-auditory cue integration may change as a function of age such that integration is heightened among older adults. Our goal was to determine whether these changes in multisensory integration are also observed in the context of self-motion perception under realistic task constraints. Thus, we developed a simulated driving paradigm in which we provided older and younger adults with visual motion cues (i.e. optic flow and systematically manipulated the presence or absence of congruent auditory cues to self-motion (i.e. engine, tire, and wind sounds. Results demonstrated that the presence or absence of congruent auditory input had different effects on older and younger adults. Both age groups demonstrated a reduction in speed variability when auditory cues were present compared to when they were absent, but older adults demonstrated a proportionally greater reduction in speed variability under combined sensory conditions. These results are consistent with evidence indicating that multisensory integration is heightened in older adults. Importantly, this study is the first to provide evidence to suggest that age differences in multisensory integration may generalize from simple stimulus detection tasks to the integration of the more complex and dynamic visual and auditory cues that are experienced during self-motion.

  1. VGC analyzer: a software for statistical analysis of fully crossed multiple-reader multiple-case visual grading characteristics studies

    International Nuclear Information System (INIS)

    Baath, Magnus; Hansson, Jonny

    2016-01-01

    Visual grading characteristics (VGC) analysis is a non-parametric rank-invariant method for analysis of visual grading data. In VGC analysis, image quality ratings for two different conditions are compared by producing a VGC curve, similar to how the ratings for normal and abnormal cases in receiver operating characteristic (ROC) analysis are used to create an ROC curve. The use of established ROC software for the analysis of VGC data has therefore previously been proposed. However, the ROC analysis is based on the assumption of independence between normal and abnormal cases. In VGC analysis, this independence cannot always be assumed, e.g. if the ratings are based on the same patients imaged under both conditions. A dedicated software intended for analysis of VGC studies, which takes possible dependencies between ratings into account in the statistical analysis of a VGC study, has therefore been developed. The software-VGC Analyzer-determines the area under the VGC curve and its uncertainty using non-parametric re-sampling techniques. This article gives an introduction to VGC Analyzer, describes the types of analyses that can be performed and instructs the user about the input and output data. (authors)

  2. How to improve the on-site MOE assessment of old timber beams combining NDT and visual strength grading

    Science.gov (United States)

    Cavalli, Alberto; Togni, Marco

    2013-09-01

    For the conservation and restoration of old timber structures, the knowledge of the mechanical properties of each element is fundamental. For this reason, various nondestructive techniques were developed and investigated since the 1990s. Some of them provide very good results, but the solutions and the proposed models were applied only in few circumstances as a consequence of the on-site restrictive working conditions: no possibility to remove the elements, limitation to ends and faces accessibility and unknown density. The on-site inspection, including the visual strength grading, has been identified as the first step for the timber assessment. In this research, 13 old timber members of Silver Fir (Abies alba Mill.) were visually graded and tested with different nondestructive techniques for the density and modulus of elasticity (MOE) estimation: flexural and longitudinal vibrational tests, stress wave transmission time and Pilodyn penetration depth. The timber elements were also tested in a four-point bending test to determinate the local and global MOE. Finally, a reliable method, applicable to the limiting on-site conditions, was proposed and the results were showed.

  3. N1 enhancement in synesthesia during visual and audio-visual perception in semantic cross-modal conflict situations: an ERP study

    Directory of Open Access Journals (Sweden)

    Christopher eSinke

    2014-01-01

    Full Text Available Synesthesia entails a special kind of sensory perception, where stimulation in one sensory modality leads to an internally generated perceptual experience of another, not stimulated sensory modality. This phenomenon can be viewed as an abnormal multisensory integration process as here the synesthetic percept is aberrantly fused with the stimulated modality. Indeed, recent synesthesia research has focused on multimodal processing even outside of the specific synesthesia-inducing context and has revealed changed multimodal integration, thus suggesting perceptual alterations at a global level. Here, we focused on audio-visual processing in synesthesia using a semantic classification task in combination with visually or auditory-visually presented animated and inanimated objects in an audio-visual congruent and incongruent manner. Fourteen subjects with auditory-visual and/or grapheme-color synesthesia and 14 control subjects participated in the experiment. During presentation of the stimuli, event-related potentials were recorded from 32 electrodes. The analysis of reaction times and error rates revealed no group differences with best performance for audio-visually congruent stimulation indicating the well-known multimodal facilitation effect. We found an enhanced amplitude of the N1 component over occipital electrode sites for synesthetes compared to controls. The differences occurred irrespective of the experimental condition and therefore suggest a global influence on early sensory processing in synesthetes.

  4. DYNAMICS OF THE COMPELEX FORMS OF VISUAL PERCEPTION IN CHILDREN OF PRE-SCHOOL AGE (A NEUROPSYCHOLOGICAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Neli VASILEVA

    2015-11-01

    Full Text Available Introduction: Experimental data in preschool aged children proves the determining role of the auditory and visual processes for future reading skills, therefore the investigation of complex forms of visual perception in this age period is diagnostically important. Objectives: Basic aim of the research is assessment of the sensitive period for the non-verbal perceptive operations in pre-school aged children, and determination of subgroup with low results for non-verbal perception. Methods: The dynamics of the visual per-ception (visual gnosis in typically develop¬ing children were tested with an adapted version of the Poppelreuter-Ghent Test for figure-ground segregation. The total number of overlapping objects is 33, grouped accor¬ding to the level of difficulty. The children are given a group of objects separately in a following sequence and they should segregate and name the objects. Results: A number of 365 typically developing children without diagnosis of visual disorders and without corrected visus took part in the research. All children, aged 4, 5, and 6 from three different settlements attend state nursery schools and have Bulgarian as a mother tongue. A three-factor dispersion analysis was held to define the statistical significance of the independent factors age, gender and settlement. The research’s data define the 5 year olds as sensitive about the dynamics of the complex forms of visual perception, compared to the four year old children (pperceptive operations in the females (F = 1,346, p

  5. FIRST AND THIRD GRADE STUDENTS’ PERCEPTIONS ON THEIR SOFT SKILLS ACQUISITION OF THE USE OF COLLABORATIVE LEARNING IN ENGLISH CLASS

    Directory of Open Access Journals (Sweden)

    Nia Nuryanti Permata

    2017-09-01

    Full Text Available Soft skills are needed to have a successful life and career for students and can be trained in classroom by conducting collaborative learning. Then, polytechnic students have collaboration learning in their English classroom activity which is useful for their soft skills achivements. However, the students which have different level can have different perceptions on it. This research tries to compare students’ perceptions on their soft skills acquirement in the use of collaborative learning in English classroom in a state polytechnic. The first group is the freshmen, meanwhile the second group is the third grade students of Diploma 3. The study employs a qualitative research design, which is a case study. The data are gained from questionnaire, then observation and interviews are used to triangulate the data. The findings show that the freshmen perceive that they acquire soft skills in 90.9%, meanwhile the third graders are in 84.9%. This concludes that freshmen soft skills acquirement is higher than the third graders. It is recommended that collaborative learning method should be continued to be used to develop the students’ soft skills, and the type of collaborative learning should be more appropriate for different grades of students

  6. Study of the perception of visual motion in amblyopia using functional MRI

    International Nuclear Information System (INIS)

    Lu Guangming; Zhang Zhiqiang; Zhou Wenzhen; Zheng Ling; Yin Jie; Liang Ping

    2006-01-01

    Objective: To research the pathophysiological mechanism of anisometropic and strabismic amblyopia through observation of the cortex activation under the stimulus of visual motion using functional MRI (fMRI). Methods: Seven patients with anisometropic amblyopia and 10 patients with strabismic amblyopia were examined under the stimulus with the paradigm that task and control states were rotating and stationary grating with 1.5 T MR scanners. The data were processed using software of SPM offline, and the result was analyzed with single subject. An index of interocular difference of activation (IDA) was set for Mann-Whitney rank sum test to denote the extension of difference between activation of each eye. Results: There appeared activation on bilaterally occipital lobe in both group of amblyopia patients. There was mild activation on frontal lobe when amblyopic eyes were stimulated, but no activation when sound eyes. The MT area was regarded as region of interesting when analyzed, the activation of all sound eyes was stronger than amblyopic eyes in 7 anisometropic amblyopia patients. There were 5 patients whose level of activation of amblyopic eye's were lower than sound eye, and four were higher than sound eye, among the strabismic amblyopia patients except one patient's activation was none. There was statistical difference between IDA value of two groups (Z=2.382, P=0.017). Conclusion: There are more cortex areas activated of amblyopic eye than sound eye when single eye is stimulated. The function of visual motion maybe has been affected in anisometropic amblyopia. In strabismic amblyopia, the function of visual motion may relate to the underlying mechanism of strabismic, which suggests, as for the impairment of perception of visual motion, there is difference between two types of amblyopia. (authors)

  7. Influence of Visual Motion, Suggestion, and Illusory Motion on Self-Motion Perception in the Horizontal Plane.

    Directory of Open Access Journals (Sweden)

    Steven David Rosenblatt

    Full Text Available A moving visual field can induce the feeling of self-motion or vection. Illusory motion from static repeated asymmetric patterns creates a compelling visual motion stimulus, but it is unclear if such illusory motion can induce a feeling of self-motion or alter self-motion perception. In these experiments, human subjects reported the perceived direction of self-motion for sway translation and yaw rotation at the end of a period of viewing set visual stimuli coordinated with varying inertial stimuli. This tested the hypothesis that illusory visual motion would influence self-motion perception in the horizontal plane. Trials were arranged into 5 blocks based on stimulus type: moving star field with yaw rotation, moving star field with sway translation, illusory motion with yaw, illusory motion with sway, and static arrows with sway. Static arrows were used to evaluate the effect of cognitive suggestion on self-motion perception. Each trial had a control condition; the illusory motion controls were altered versions of the experimental image, which removed the illusory motion effect. For the moving visual stimulus, controls were carried out in a dark room. With the arrow visual stimulus, controls were a gray screen. In blocks containing a visual stimulus there was an 8s viewing interval with the inertial stimulus occurring over the final 1s. This allowed measurement of the visual illusion perception using objective methods. When no visual stimulus was present, only the 1s motion stimulus was presented. Eight women and five men (mean age 37 participated. To assess for a shift in self-motion perception, the effect of each visual stimulus on the self-motion stimulus (cm/s at which subjects were equally likely to report motion in either direction was measured. Significant effects were seen for moving star fields for both translation (p = 0.001 and rotation (p0.1 for both. Thus, although a true moving visual field can induce self-motion, results of this

  8. Mathematics and science acceleration in grade eight: School leaders' perceptions and satisfaction

    Science.gov (United States)

    Graham, Kenneth

    Shifts in attitudes regarding academic program accessibility to provide the most rigorous academic opportunities to all students will not occur smoothly without departmental level leaders who believe in the potential benefits of accelerating larger numbers of students. Without the support and the belief of the department level leadership, practices such as open enrollment and universal acceleration that target school equity will be doomed to failure. This study was conducted using a questionnaire developed by the researcher called the Perceptions of Acceleration and Leadership Survey. The survey was distributed to all math and science department leaders within a suburban region of New York. The survey sought to determine how the perceptions of acceleration, job satisfaction, self-efficacy, and role longevity for the department level leaders are impacted by their personal demographics, professional characteristics, and community characteristics. The study did not reveal any statistically significant differences among department level leaders' personal, professional, and community characteristics with respect to perceptions of acceleration. There were significant differences for job satisfaction, self-efficacy, and role longevity for several intervening and independent variables within the study. Statistically significant correlations were found between beliefs in college preparation and perceptions of acceleration as well as relationships with the community and perceptions of acceleration. The results indicate the importance of hiring department leaders who recognize the potential for accelerating more students, hiring more ethnically diverse candidates for these leadership positions, affording department level leaders with significant professional development, and evaluation of administrative structures to maximize student success.

  9. Visual perception of dynamic properties: cue heuristics versus direct-perceptual competence.

    Science.gov (United States)

    Runeson, S; Juslin, P; Olsson, H

    2000-07-01

    Constructivist and Gibsonian approaches disagree over the possibility of direct perceptual use of advanced information. A trenchant instance concerns visual perception of underlying dynamic properties as specified by kinematic patterns of events. For the paradigmatic task of discrimination of relative mass in observed collisions, 2 mathematical models are developed, 1 model representing a direct, invariant-based approach, and 1 representing a cue-heuristic approach. The models enable a critical experimental design with distinct predictions concerning performance data and confidence ratings. Although pretraining results were mixed, the invariant-based model was empirically confirmed after a minimal amount of training: Competence entails the use of advanced kinematic information in a direct-perceptual ("sensory") mode of apprehension, in contrast to beginners' use of simpler cues in an inferential ("cognitive") mode.

  10. VISUAL PERCEPTION BASED AUTOMATIC RECOGNITION OF CELL MOSAICS IN HUMAN CORNEAL ENDOTHELIUMMICROSCOPY IMAGES

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    Yann Gavet

    2011-05-01

    Full Text Available The human corneal endothelium can be observed with two types of microscopes: classical optical microscope for ex-vivo imaging, and specular optical microscope for in-vivo imaging. The quality of the cornea is correlated to the endothelial cell density and morphometry. Automatic methods to analyze the human corneal endothelium images are still not totally efficient. Image analysis methods that focus only on cell contours do not give good results in presence of noise and of bad conditions of acquisition. More elaborated methods introduce regional informations in order to performthe cell contours completion, thus implementing the duality contour-region. Their good performance can be explained by their connections with several basic principles of human visual perception (Gestalt Theory and Marr's computational theory.

  11. Organic Boundary Location Based on Color-Texture of Visual Perception in Wireless Capsule Endoscopy Video

    Directory of Open Access Journals (Sweden)

    Chengliang Wang

    2018-01-01

    Full Text Available This paper addresses the problem of automatically locating the boundary between the stomach and the small intestine (the pylorus in wireless capsule endoscopy (WCE video. For efficient image segmentation, the color-saliency region detection (CSD method is developed for obtaining the potentially valid region of the frame (VROF. To improve the accuracy of locating the pylorus, we design the Monitor-Judge model. On the one hand, the color-texture fusion feature of visual perception (CTVP is constructed by grey level cooccurrence matrix (GLCM feature from the maximum moments of the phase congruency covariance and hue-saturation histogram feature in HSI color space. On the other hand, support vector machine (SVM classifier with the CTVP feature is utilized to locate the pylorus. The experimental results on 30 real WCE videos demonstrate that the proposed location method outperforms the related valuable techniques.

  12. Auditory-Visual Speech Perception in Three- and Four-Year-Olds and Its Relationship to Perceptual Attunement and Receptive Vocabulary

    Science.gov (United States)

    Erdener, Dogu; Burnham, Denis

    2018-01-01

    Despite the body of research on auditory-visual speech perception in infants and schoolchildren, development in the early childhood period remains relatively uncharted. In this study, English-speaking children between three and four years of age were investigated for: (i) the development of visual speech perception--lip-reading and visual…

  13. VISUAL PERCEPTION SPECIFICS OF CHILDREN WITH ASD AS A DETERMINANT FOR EDUCATIONAL ENVIRONMENT OUTLINETIMES

    Directory of Open Access Journals (Sweden)

    Tatiana Bystrova

    2017-06-01

    Full Text Available The idea of inclusive education raises the question of security of children with autism spectrum disorders (ASD. It is the imperative of the time to create teaching materials that promote the effective implementation of educational curriculum. However, we have to stress the fact that most of the evaluable nowadays teaching materials have been created spontaneously, without any reliable criteria. Our primary hypothesis is that children with ASD have specific features of visual perception that do not depend on the state of their intelligence, which is confirmed by empirical data obtained by the authors. Our secondary hypothesis, specified in the process of research, stipulates that children with ASD will differently perceive different graphic images executed in different styles. These findings are further confirmed by empirical data collected by the authors in the study of perception and understanding of different graphic images by children with ASD and mental retardation. On the basis of theoretical and empirical data we specified the criteria for graphic design products which play a pivotal role in the formation of school educational environment. In this respect we focus on the criteria for design materials (including design criteria provisions, formulated by Norman, which he addressed to practicing designers.

  14. Visual perception affected by motivation and alertness controlled by a noninvasive brain-computer interface.

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    Vladimir A Maksimenko

    Full Text Available The influence of motivation and alertness on brain activity associated with visual perception was studied experimentally using the Necker cube, which ambiguity was controlled by the contrast of its ribs. The wavelet analysis of recorded multichannel electroencephalograms (EEG allowed us to distinguish two different scenarios while the brain processed the ambiguous stimulus. The first scenario is characterized by a particular destruction of alpha rhythm (8-12 Hz with a simultaneous increase in beta-wave activity (20-30 Hz, whereas in the second scenario, the beta rhythm is not well pronounced while the alpha-wave energy remains unchanged. The experiments were carried out with a group of financially motivated subjects and another group of unpaid volunteers. It was found that the first scenario occurred mainly in the motivated group. This can be explained by the increased alertness of the motivated subjects. The prevalence of the first scenario was also observed in a group of subjects to whom images with higher ambiguity were presented. We believe that the revealed scenarios can occur not only during the perception of bistable images, but also in other perceptual tasks requiring decision making. The obtained results may have important applications for monitoring and controlling human alertness in situations which need substantial attention. On the base of the obtained results we built a brain-computer interface to estimate and control the degree of alertness in real time.

  15. Visual presentation of a medical physiology seminar modifies dental students' perception of its clinical significance.

    Science.gov (United States)

    Vuletic, L; Spalj, S; Peros, K

    2016-02-01

    The primary objective of this study was to assess whether exposing dental students to visual stimuli related to dental profession during the medical physiology seminar could affect their perception of the clinical relevance of the topic. A self-administered questionnaire on attitudes towards medical physiology was conducted amongst 105 students of the School of Dental Medicine in Zagreb, Croatia, aged 19-24 years (80% females) following a seminar on respiratory system physiology. Power-point presentation accompanying the seminar for a total of 52 students (study group) was enriched with pictures related to dental practice in order to assess whether these pictures could make the topic appear more clinically relevant for a future dentist. The results of the survey indicated that dental students in the study group perceived the topic of the seminar as more important for them as future dentists when compared to the perception of the control group (P = 0.025). The results of this survey encourage physiology lecturers to present medical physiology as clinically relevant for dental students whenever possible as this could increase students' interest in the subject and their motivation for learning. Such an approach could be particularly beneficial if there is a significant time gap between basic courses and involvement of students into clinical training for it could promote meaningful learning. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. First-person and third-person verbs in visual motion-perception regions.

    Science.gov (United States)

    Papeo, Liuba; Lingnau, Angelika

    2015-02-01

    Verb-related activity is consistently found in the left posterior lateral cortex (PLTC), encompassing also regions that respond to visual-motion perception. Besides motion, those regions appear sensitive to distinctions among the entities beyond motion, including that between first- vs. third-person ("third-person bias"). In two experiments, using functional magnetic resonance imaging (fMRI), we studied whether the implied subject (first/third-person) and/or the semantic content (motor/non-motor) of verbs modulate the neural activity in the left PLTC-regions responsive during basic- and biological-motion perception. In those sites, we found higher activity for verbs than for nouns. This activity was modulated by the person (but not the semantic content) of the verbs, with stronger response to third- than first-person verbs. The third-person bias elicited by verbs supports a role of motion-processing regions in encoding information about the entity beyond (and independently from) motion, and sets in a new light the role of these regions in verb processing. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. The Holistic Processing Account of Visual Expertise in Medical Image Perception: A Review.

    Science.gov (United States)

    Sheridan, Heather; Reingold, Eyal M

    2017-01-01

    In the field of medical image perception, the holistic processing perspective contends that experts can rapidly extract global information about the image, which can be used to guide their subsequent search of the image (Swensson, 1980; Nodine and Kundel, 1987; Kundel et al., 2007). In this review, we discuss the empirical evidence supporting three different predictions that can be derived from the holistic processing perspective: Expertise in medical image perception is domain-specific, experts use parafoveal and/or peripheral vision to process large regions of the image in parallel, and experts benefit from a rapid initial glimpse of an image. In addition, we discuss a pivotal recent study (Litchfield and Donovan, 2016) that seems to contradict the assumption that experts benefit from a rapid initial glimpse of the image. To reconcile this finding with the existing literature, we suggest that global processing may serve multiple functions that extend beyond the initial glimpse of the image. Finally, we discuss future research directions, and we highlight the connections between the holistic processing account and similar theoretical perspectives and findings from other domains of visual expertise.

  18. Quantifying the visual perception skills of pre-school testees using a novel tangible electronic test instrument

    CSIR Research Space (South Africa)

    Smith, Andrew C

    2008-11-01

    Full Text Available an assessment instrument that directly measures pre-school children’s visual perception skills that form part of literacy skills, as defined in the Persona Object Model in order to provide information that could contribute to the design of appropriate game...

  19. Integrating Conjoint Analysis with TOPSIS Algorithm to the Visual Effect of Icon Design Based on Multiple Users' Image Perceptions

    Science.gov (United States)

    Tung, Ting-Chun; Chen, Hung-Yuan

    2017-01-01

    With the advance of mobile computing and wireless technology, a user's intent to interact with the interface of a mobile device is motivated not only by its intuitional operation, but also by the emotional perception induced by its aesthetic appeal. A graphical interface employing icons with suitable visual effect based on the users' emotional…

  20. Basic to Applied Research: The Benefits of Audio-Visual Speech Perception Research in Teaching Foreign Languages

    Science.gov (United States)

    Erdener, Dogu

    2016-01-01

    Traditionally, second language (L2) instruction has emphasised auditory-based instruction methods. However, this approach is restrictive in the sense that speech perception by humans is not just an auditory phenomenon but a multimodal one, and specifically, a visual one as well. In the past decade, experimental studies have shown that the…

  1. Teaching with Concrete and Abstract Visual Representations: Effects on Students' Problem Solving, Problem Representations, and Learning Perceptions

    Science.gov (United States)

    Moreno, Roxana; Ozogul, Gamze; Reisslein, Martin

    2011-01-01

    In 3 experiments, we examined the effects of using concrete and/or abstract visual problem representations during instruction on students' problem-solving practice, near transfer, problem representations, and learning perceptions. In Experiments 1 and 2, novice students learned about electrical circuit analysis with an instructional program that…

  2. Influence of Building Materials with Directional Textures on the Visual Perceptions of Elderly with Alzheimer’s Disease

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    Yao Rong Hwang

    2014-09-01

    Conclusion: Data about these building materials should be made available for the reference of caregivers and building managers, in order to prevent the demented elderly from having behavior problems due to environmental design. Lastly, further study is required to confirm if the building materials’ influence on visual perceptions in the demented elderly correlates to the variables of age, sex, and severity of disease.

  3. Affordance-based perception-action dynamics: A model of visually guided braking.

    Science.gov (United States)

    Harrison, Henry S; Turvey, Michael T; Frank, Till D

    2016-04-01

    Behavioral dynamics is a framework for understanding adaptive behavior as arising from the self-organizing interaction between animal and environment. The methods of nonlinear dynamics provide a language for describing behavior that is both stable and flexible. Behavioral dynamics has been criticized for ignoring the animal's sensitivity to its own capabilities, leading to the development of an alternative framework: affordance-based control. Although it is theoretically sound and empirically motivated, affordance-based control has resisted characterization in terms of nonlinear dynamics. Here, we provide a dynamical description of affordance-based control, extending behavioral dynamics to meet its criticisms. We propose a general modeling strategy consistent with both theories. We use visually guided braking as a representative behavior and construct a novel dynamical model. This model demonstrates the possibility of understanding visually guided action as respecting the limits of the actor's capabilities, while still being guided by informational variables associated with desired states of affairs. In addition to such "hard" constraints on behavior, our framework allows for the influence of "soft" constraints such as preference and comfort, opening a new area of inquiry in perception-action dynamics. (c) 2016 APA, all rights reserved).

  4. Hybrid fNIRS-EEG based classification of auditory and visual perception processes

    Directory of Open Access Journals (Sweden)

    Felix ePutze

    2014-11-01

    Full Text Available For multimodal Human-Computer Interaction (HCI, it is very useful to identify the modalities on which the user is currently processing information. This would enable a system to select complementary output modalities to reduce the user's workload. In this paper, we develop a hybrid Brain-Computer Interface (BCI which uses Electroencephalography (EEG and functional Near Infrared Spectroscopy (fNIRS to discriminate and detect visual and auditory stimulus processing. We describe the experimental setup we used for collection of our data corpus with 12 subjects. We present cross validation evaluation results for different classification conditions. We show that our subject-dependent systems achieved a classification accuracy of 97.8% for discriminating visual and auditory perception processes from each other and a classification accuracy of up to 94.8% for detecting modality-specific processes independently of other cognitive activity. The same classification conditions could also be discriminated in a subject-independent fashion with accuracy of up to 94.6% and 86.7%, respectively. We also look at the contributions of the two signal types and show that the fusion of classifiers using different features significantly increases accuracy.

  5. Use of Collage Technique in Modern Art Perceptions of Visual Arts Teacher Candidates: Action Research

    Directory of Open Access Journals (Sweden)

    Görkem Utku ALPARSLAN

    2018-01-01

    Full Text Available The purpose of the research is to demonstrate the contribution of the collage technique to modern art perceptions of visual arts teacher candidates. Research has been designed in the form of an action research from qualitative research methods. The study was conducted for eight weeks. The data of the study, the student journals and the pictures of the students before, during and after the application were collected and evaluated by rubric. In the study, it was found that students 'pictures of rubbing their images with rubbing techniques developed as a result of modern formal intellectual and formative reflection and as a result of the descriptive analysis of qualitative data, students' awareness of modern visual intellectual and formal foundations and collage technique increased. As a result of the research, the level of skill of expressing modern formal expression was observed in the students' work and it was determined that the awareness of students about the formal and intellectual structure of modern picture and collage technique increased in the frame of originality, criticism and creativity.

  6. Visual Perception by Drivers of the Advertisements Located at Selected Major Routes

    Science.gov (United States)

    Bichajło, Lesław

    2017-10-01

    This article characterizes the research based on the analysis of the eye fixation points on the advertisements. The research has been realized in real road and traffic conditions. The group of 12 drivers was equipped with the glasses occulometric measurement system mounted on the driver’s head. The participants were driving their private cars. The analysis was concentrated on the fixations on the advertisement tables located along the selected national roads in Rzeszów area (Poland). For better recognition if the advertisements have distracted the drivers the number of fixations on the advertisements has been compared with the fixations on the road signs. The active drivers have observed many visual attractors like advertisements, road signs and cars being ahead and on another lane. Passive drivers have low number of fixations on road signs and advertisements. Their fixations typically have been localized on survey and they probably used the peripheral vision in order to recognition of road sign shapes. The results show, that: the percentage of fixations on the advertisement and road signs is different for each participants; the highest percentage of fixated advertisements was on the section with small number of advertisements, but in the city area, when a group of advertisements was on the road, the participants selected some of them, yet no participant fixated all advertisements localized in a small distance between them; the single advertisement visible from the long distance strongly attracts the visual perception; the percentage of the fixated advertisements was higher than road signs.

  7. Playing the electric light orchestra--how electrical stimulation of visual cortex elucidates the neural basis of perception.

    Science.gov (United States)

    Cicmil, Nela; Krug, Kristine

    2015-09-19

    Vision research has the potential to reveal fundamental mechanisms underlying sensory experience. Causal experimental approaches, such as electrical microstimulation, provide a unique opportunity to test the direct contributions of visual cortical neurons to perception and behaviour. But in spite of their importance, causal methods constitute a minority of the experiments used to investigate the visual cortex to date. We reconsider the function and organization of visual cortex according to results obtained from stimulation techniques, with a special emphasis on electrical stimulation of small groups of cells in awake subjects who can report their visual experience. We compare findings from humans and monkeys, striate and extrastriate cortex, and superficial versus deep cortical layers, and identify a number of revealing gaps in the 'causal map' of visual cortex. Integrating results from different methods and species, we provide a critical overview of the ways in which causal approaches have been used to further our understanding of circuitry, plasticity and information integration in visual cortex. Electrical stimulation not only elucidates the contributions of different visual areas to perception, but also contributes to our understanding of neuronal mechanisms underlying memory, attention and decision-making.

  8. Playing the electric light orchestra—how electrical stimulation of visual cortex elucidates the neural basis of perception

    Science.gov (United States)

    Cicmil, Nela; Krug, Kristine

    2015-01-01

    Vision research has the potential to reveal fundamental mechanisms underlying sensory experience. Causal experimental approaches, such as electrical microstimulation, provide a unique opportunity to test the direct contributions of visual cortical neurons to perception and behaviour. But in spite of their importance, causal methods constitute a minority of the experiments used to investigate the visual cortex to date. We reconsider the function and organization of visual cortex according to results obtained from stimulation techniques, with a special emphasis on electrical stimulation of small groups of cells in awake subjects who can report their visual experience. We compare findings from humans and monkeys, striate and extrastriate cortex, and superficial versus deep cortical layers, and identify a number of revealing gaps in the ‘causal map′ of visual cortex. Integrating results from different methods and species, we provide a critical overview of the ways in which causal approaches have been used to further our understanding of circuitry, plasticity and information integration in visual cortex. Electrical stimulation not only elucidates the contributions of different visual areas to perception, but also contributes to our understanding of neuronal mechanisms underlying memory, attention and decision-making. PMID:26240421

  9. Convergence of Observer Ratings and Student Perceptions of Reform Practices in Sixth-Grade Mathematics Classrooms

    Science.gov (United States)

    Ellis, Mark W.; Malloy, Carol E.; Meece, Judith L.; Sylvester, Patricia R.

    2007-01-01

    As part of a research project examining relationships between instructional practices and student cognitive and social outcomes in middle-school mathematics classes, external observers and students reported perceptions of teachers' instructional practices. The extent to which students in classrooms identified by external raters as reform-oriented…

  10. 'Time-shrinking perception' in the visual system: a psychophysical and high-density ERP study.

    Science.gov (United States)

    Nagaike, Atsushi; Mitsudo, Takako; Nakajima, Yoshitaka; Ogata, Katsuya; Yamasaki, Takao; Goto, Yoshinobu; Tobimatsu, Shozo

    2016-11-01

    'Time-shrinking perception (TSP)' is a unique perceptual phenomenon in which the duration of two successive intervals (T1 and T2) marked by three auditory stimuli is perceived as equal even when they are physically different. This phenomenon provides a link between time and working memory; however, previous studies have mainly been performed on the auditory modality but not the visual modality. To clarify the neural mechanism of visual TSP, we performed a psychophysical experiment and recorded event-related potentials (ERPs) under different T1/T2 combinations. Three successive black/white sinusoidal gratings (30 ms duration) were presented to the participants. In the psychophysical experiment, either T1 or T2 was varied from 240 to 560 ms in 40-ms steps, while T2 or T1 was fixed at 400 ms. Participants judged whether T1 and T2 were equal or not by pressing a button. ERPs were recorded from 128 scalp electrodes, while T1 was varied from 240, 320, and 400 ms with the 400 ms T2 duration, and vice versa. Behavioral data showed asymmetrical assimilation: When -80 ms ≤ (T1 - T2) ≤ +120 ms, TSP was observed in the T1-varied condition. When -120 ms ≤ (T1 - T2) ≤ +80 ms, it was also observed in the T2-varied condition. These asymmetric time ranges in vision were different from those in the auditory modality. ERP data showed that contingent negative variation (CNV) appeared in the fronto-central region at around 300-500 ms during T2 presentation in the T1  T2 condition. In the /400/240/ pattern, P3 amplitude was greater than those of other temporal patterns. These neural responses corresponded to participants' perception that T1 and T2 were not equal. The neural responses in the fronto-central region were involved with endogenous temporal attention for discrimination. Moreover, neural responses in the parietal region were engaged in exogenous temporal attention. Therefore, fronto-parietal neural responses underlie temporal perception in vision.

  11. Exploring Perceptions of University Students Pertaining to Grades over Knowledge and Skills

    Science.gov (United States)

    Hasnain, Asma; Bhamani, Shelina

    2014-01-01

    The aim of the research was to study the phenomenon surrounding the perspective of university students preferring grades to knowledge and skills. Three currently enrolled participants were selected from different private universities of Karachi. Participants' interviews were examined through thematic analysis. The findings suggested that students…

  12. A Phenomenological Study of Ninth Grade Students' with Disabilities Perceptions of Educational Settings

    Science.gov (United States)

    Talley, Micole Atkins

    2017-01-01

    Few research studies listened to the voices of high school students with disabilities' regarding their lived experiences during placement in an inclusion setting and a resource setting. The purpose of this qualitative, phenomenological study was to understand the central phenomenon of the study for 10 ninth grade students with disabilities served…

  13. Non-Governmental Organization (NGO Libraries for The Visually Impaired in Nigeria: Alternative Format Use and Perception of Information Services

    Directory of Open Access Journals (Sweden)

    Adetoro, 'Niran

    2015-03-01

    Full Text Available Nigeria's non-government organization (NGO libraries for the visually impaired has over the years been at the forefront of information services provision to persons with visual impairment. This study adopted a survey research design to investigate use of alternative formats and perceptions of information services to the visually impaired, focusing on two purposively chosen NGO libraries for the visually impaired in Nigeria. Using a complete enumeration approach, data were gathered from 180 users of the libraries through the use of a structured questionnaire with a reliability score (${\\alpha}=0.74$. Data from 112 (62.2% of the 180 administered copies of a questionnaire that were retrieved were analysed. The study found that Braille materials had a high level of utilization ($\\bar{x}=4.46$ and were the most frequently utilized (90.9%. Perception of information services by the visually impaired was positive while use of alternative formats was significantly and positively related to users' perception of information services (r = .041; p < 0.05. The study recommends improved transcription and investment in alternative formats and in e-resources. It also recommends collaborations to widen access as well as constant evaluation of services.

  14. Audio-visual speech perception in prelingually deafened Japanese children following sequential bilateral cochlear implantation.

    Science.gov (United States)

    Yamamoto, Ryosuke; Naito, Yasushi; Tona, Risa; Moroto, Saburo; Tamaya, Rinko; Fujiwara, Keizo; Shinohara, Shogo; Takebayashi, Shinji; Kikuchi, Masahiro; Michida, Tetsuhiko

    2017-11-01

    An effect of audio-visual (AV) integration is observed when the auditory and visual stimuli are incongruent (the McGurk effect). In general, AV integration is helpful especially in subjects wearing hearing aids or cochlear implants (CIs). However, the influence of AV integration on spoken word recognition in individuals with bilateral CIs (Bi-CIs) has not been fully investigated so far. In this study, we investigated AV integration in children with Bi-CIs. The study sample included thirty one prelingually deafened children who underwent sequential bilateral cochlear implantation. We assessed their responses to congruent and incongruent AV stimuli with three CI-listening modes: only the 1st CI, only the 2nd CI, and Bi-CIs. The responses were assessed in the whole group as well as in two sub-groups: a proficient group (syllable intelligibility ≥80% with the 1st CI) and a non-proficient group (syllable intelligibility speech perception with the 2nd CI in the non-proficient group, suggesting that Bi-CIs listeners with poorer speech recognition rely on visual information more compared to the proficient subjects to compensate for poorer auditory input. Nevertheless, poorer quality auditory input with the 2nd CI did not interfere with AV integration with binaural listening (with Bi-CIs). Overall, the findings of this study might be used to inform future research to identify the best strategies for speech training using AV integration effectively in prelingually deafened children. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Virtual lesion of right posterior superior temporal sulcus modulates conscious visual perception of fearful expressions in faces and bodies.

    Science.gov (United States)

    Candidi, Matteo; Stienen, Bernard M C; Aglioti, Salvatore M; de Gelder, Beatrice

    2015-04-01

    The posterior Superior Temporal Suclus (pSTS) represents a central hub in the complex cerebral network for person perception and emotion recognition as also suggested by its heavy connections with face- and body-specific cortical (e.g., the fusiform face area, FFA and the extrastriate body area, EBA) and subcortical structures (e.g., amygdala). Information on whether pSTS is causatively involved in sustaining conscious visual perception of emotions expressed by faces and bodies is lacking. We explored this issue by combining a binocular rivalry procedure (where emotional and neutral face and body postures rivaled with house images) with off-line, 1-Hz repetitive transcranial magnetic stimulation (rTMS). We found that temporary inhibition of the right pSTS reduced perceptual dominance of fearful faces and increased perceptual dominance of fearful bodies, while leaving unaffected the perception of neutral face and body images. Inhibition of the vertex had no effect on conscious visual perception of neutral or emotional face or body stimuli. Thus, the right pSTS plays a causal role in shortening conscious vision of fearful faces and in prolonging conscious vision of fearful bodies. These results suggest that pSTS selectively modulates the activity of segregated networks involved in the conscious visual perception of emotional faces or bodies. We speculate that the opposite role of the right pSTS for conscious perception of fearful face and body may be explained by the different connections that this region entertains with face- and body-selective visual areas as well as with amygdalae and premotor regions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. A novel iris transillumination grading scale allowing flexible assessment with quantitative image analysis and visual matching.

    Science.gov (United States)

    Wang, Chen; Brancusi, Flavia; Valivullah, Zaheer M; Anderson, Michael G; Cunningham, Denise; Hedberg-Buenz, Adam; Power, Bradley; Simeonov, Dimitre; Gahl, William A; Zein, Wadih M; Adams, David R; Brooks, Brian

    2018-01-01

    To develop a sensitive scale of iris transillumination suitable for clinical and research use, with the capability of either quantitative analysis or visual matching of images. Iris transillumination photographic images were used from 70 study subjects with ocular or oculocutaneous albinism. Subjects represented a broad range of ocular pigmentation. A subset of images was subjected to image analysis and ranking by both expert and nonexpert reviewers. Quantitative ordering of images was compared with ordering by visual inspection. Images were binned to establish an 8-point scale. Ranking consistency was evaluated using the Kendall rank correlation coefficient (Kendall's tau). Visual ranking results were assessed using Kendall's coefficient of concordance (Kendall's W) analysis. There was a high degree of correlation among the image analysis, expert-based and non-expert-based image rankings. Pairwise comparisons of the quantitative ranking with each reviewer generated an average Kendall's tau of 0.83 ± 0.04 (SD). Inter-rater correlation was also high with Kendall's W of 0.96, 0.95, and 0.95 for nonexpert, expert, and all reviewers, respectively. The current standard for assessing iris transillumination is expert assessment of clinical exam findings. We adapted an image-analysis technique to generate quantitative transillumination values. Quantitative ranking was shown to be highly similar to a ranking produced by both expert and nonexpert reviewers. This finding suggests that the image characteristics used to quantify iris transillumination do not require expert interpretation. Inter-rater rankings were also highly similar, suggesting that varied methods of transillumination ranking are robust in terms of producing reproducible results.

  17. Developmental changes in reading do not alter the development of visual processing skills: An application of explanatory item response models in grades K-2

    Directory of Open Access Journals (Sweden)

    Kristi L Santi

    2015-02-01

    Full Text Available Visual processing has been widely studied in regard to its impact on a students’ ability to read. A less researched area is the role of reading in the development of visual processing skills. A cohort-sequential, accelerated-longitudinal design was utilized with 932 kindergarten, first, and second grade students to examine the impact of reading acquisition on the processing of various types of visual discrimination and visual motor test items. Students were assessed four times per year on a variety of reading measures and reading precursors and two popular measures of visual processing over a three-year period. Explanatory item response models were used to examine the roles of person and item characteristics on changes in visual processing abilities and changes in item difficulties over time. Results showed different developmental patterns for five types of visual processing test items, but most importantly failed to show consistent effects of learning to read on changes in item difficulty. Thus, the present study failed to find support for the hypothesis that learning to read alters performance on measures of visual processing. Rather, visual processing and reading ability improved together over time with no evidence to suggest cross-domain influences from reading to visual processing. Results are discussed in the context of developmental theories of visual processing and brain-based research on the role of visual skills in learning to read.

  18. Auditory, Visual, and Auditory-Visual Perception of Emotions by Individuals with Cochlear Implants, Hearing Aids, and Normal Hearing

    Science.gov (United States)

    Most, Tova; Aviner, Chen

    2009-01-01

    This study evaluated the benefits of cochlear implant (CI) with regard to emotion perception of participants differing in their age of implantation, in comparison to hearing aid users and adolescents with normal hearing (NH). Emotion perception was examined by having the participants identify happiness, anger, surprise, sadness, fear, and disgust.…

  19. Visual-motor integration, visual perception, and fine motor coordination in a population of children with high levels of Fetal Alcohol Spectrum Disorder.

    Science.gov (United States)

    Doney, Robyn; Lucas, Barbara R; Watkins, Rochelle E; Tsang, Tracey W; Sauer, Kay; Howat, Peter; Latimer, Jane; Fitzpatrick, James P; Oscar, June; Carter, Maureen; Elliott, Elizabeth J

    2016-08-01

    Visual-motor integration (VMI) skills are essential for successful academic performance, but to date no studies have assessed these skills in a population-based cohort of Australian Aboriginal children who, like many children in other remote, disadvantaged communities, consistently underperform academically. Furthermore, many children in remote areas of Australia have prenatal alcohol exposure (PAE) and Fetal Alcohol Spectrum Disorder (FASD), which are often associated with VMI deficits. VMI, visual perception, and fine motor coordination were assessed using The Beery-Buktenica Developmental Test of Visual-Motor Integration, including its associated subtests of Visual Perception and Fine Motor Coordination, in a cohort of predominantly Australian Aboriginal children (7.5-9.6 years, n=108) in remote Western Australia to explore whether PAE adversely affected test performance. Cohort results were reported, and comparisons made between children i) without PAE; ii) with PAE (no FASD); and iii) FASD. The prevalence of moderate (≤16th percentile) and severe (≤2nd percentile) impairment was established. Mean VMI scores were 'below average' (M=87.8±9.6), and visual perception scores were 'average' (M=97.6±12.5), with no differences between groups. Few children had severe VMI impairment (1.9%), but moderate impairment rates were high (47.2%). Children with FASD had significantly lower fine motor coordination scores and higher moderate impairment rates (M=87.9±12.5; 66.7%) than children without PAE (M=95.1±10.7; 23.3%) and PAE (no FASD) (M=96.1±10.9; 15.4%). Aboriginal children living in remote Western Australia have poor VMI skills regardless of PAE or FASD. Children with FASD additionally had fine motor coordination problems. VMI and fine motor coordination should be assessed in children with PAE, and included in FASD diagnostic assessments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Preoperative Quantitative MR Tractography Compared with Visual Tract Evaluation in Patients with Neuropathologically Confirmed Gliomas Grades II and III: A Prospective Cohort Study

    International Nuclear Information System (INIS)

    Delgado, Anna F.; Nilsson, Markus; Latini, Francesco; Mårtensson, Johanna; Zetterling, Maria; Berntsson, Shala G.; Alafuzoff, Irina; Lätt, Jimmy; Larsson, Elna-Marie

    2016-01-01

    Background and Purpose. Low-grade gliomas show infiltrative growth in white matter tracts. Diffusion tensor tractography can noninvasively assess white matter tracts. The aim was to preoperatively assess tumor growth in white matter tracts using quantitative MR tractography (3T). The hypothesis was that suspected infiltrated tracts would have altered diffusional properties in infiltrated tract segments compared to noninfiltrated tracts. Materials and Methods. Forty-eight patients with suspected low-grade glioma were included after written informed consent and underwent preoperative diffusion tensor imaging in this prospective review-board approved study. Major white matter tracts in both hemispheres were tracked, segmented, and visually assessed for tumor involvement in thirty-four patients with gliomas grade II or III (astrocytomas or oligodendrogliomas) on postoperative neuropathological evaluation. Relative fractional anisotropy (rFA) and mean diffusivity (rMD) in tract segments were calculated and compared with visual evaluation and neuropathological diagnosis. Results. Tract segment infiltration on visual evaluation was associated with a lower rFA and high rMD in a majority of evaluated tract segments (89% and 78%, resp.). Grade II and grade III gliomas had similar infiltrating behavior. Conclusion. Quantitative MR tractography corresponds to visual evaluation of suspected tract infiltration. It may be useful for an objective preoperative evaluation of tract segment involvement

  1. Computational modeling of unsteady third-grade fluid flow over a vertical cylinder: A study of heat transfer visualization

    Science.gov (United States)

    Reddy, G. Janardhana; Hiremath, Ashwini; Kumar, Mahesh

    2018-03-01

    The present paper aims to investigate the effect of Prandtl number for unsteady third-grade fluid flow over a uniformly heated vertical cylinder using Bejan's heat function concept. The mathematical model of this problem is given by highly time-dependent non-linear coupled equations and are resolved by an efficient unconditionally stable implicit scheme. The time histories of average values of momentum and heat transport coefficients as well as the steady-state flow variables are displayed graphically for distinct values of non-dimensional control parameters arising in the system. As the non-dimensional parameter value gets amplified, the time taken for the fluid flow variables to attain the time-independent state is decreasing. The dimensionless heat function values are closely associated with an overall rate of heat transfer. Thermal energy transfer visualization implies that the heat function contours are compact in the neighborhood of the leading edge of the hot cylindrical wall. It is noticed that the deviations of flow-field variables from the hot wall for a non-Newtonian third-grade fluid flow are significant compared to the usual Newtonian fluid flow.

  2. Examining the Effect of Age on Visual-Vestibular Self-Motion Perception Using a Driving Paradigm.

    Science.gov (United States)

    Ramkhalawansingh, Robert; Keshavarz, Behrang; Haycock, Bruce; Shahab, Saba; Campos, Jennifer L

    2017-05-01

    Previous psychophysical research has examined how younger adults and non-human primates integrate visual and vestibular cues to perceive self-motion. However, there is much to be learned about how multisensory self-motion perception changes with age, and how these changes affect performance on everyday tasks involving self-motion. Evidence suggests that older adults display heightened multisensory integration compared with younger adults; however, few previous studies have examined this for visual-vestibular integration. To explore age differences in the way that visual and vestibular cues contribute to self-motion perception, we had younger and older participants complete a basic driving task containing visual and vestibular cues. We compared their performance against a previously established control group that experienced visual cues alone. Performance measures included speed, speed variability, and lateral position. Vestibular inputs resulted in more precise speed control among older adults, but not younger adults, when traversing curves. Older adults demonstrated more variability in lateral position when vestibular inputs were available versus when they were absent. These observations align with previous evidence of age-related differences in multisensory integration and demonstrate that they may extend to visual-vestibular integration. These findings may have implications for vehicle and simulator design when considering older users.

  3. Effect of visual perception training combined with total nutrition meal sequential therapy on myopic amblyopia in preschool children

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    Hong Chen

    2017-12-01

    Full Text Available AIM: To observe the therapeutic effect of visual perception training combined with total nutrition meal sequential therapy in the treatment of myopic amblyopia. METHODS: Totally 73 children(135 eyeswith myopic amblyopia were divided into control group(36 cases, 67 eyesand treatment group(37 cases, 68 eyesaccording to random number table. The control group were treated with traditional spectaculars and grating covering combined with fine eyesight training; the treatment group were treated with visual perception training combined with total nutrient meal sequential therapy. The visual acuity, diopter and average diopter of two groups were compared before and after treatment at 3, 6mo and 1a. The curative effect of two groups of children was compared after 1a treatment. And the adverse reactions were recorded in two groups during the treatment period. The recurrence rate of amblyopia in 1a follow-up was compared between two groups. RESULTS: The difference of visual acuity between two groups was not significant at 3mo(P>0.05. The visual acuity of the treatment group was significantly higher than that of the control group at 6mo and 1a(PP>0.05, but the average annual refractive changes in the treatment group were significantly lower than that in the control group(PPPCONCLUSION: Visual perception training combined with total nutrition meal sequential therapy in the treatment of myopic amblyopia in preschool children can significantly improve patients' visual acuity, reduce the average annual diopter changes, improve the therapeutic effect, reduce the recurrence rate of amblyopia.

  4. A Century of Gestalt Psychology in Visual Perception II. Conceptual and Theoretical Foundations

    Science.gov (United States)

    Wagemans, Johan; Feldman, Jacob; Gepshtein, Sergei; Kimchi, Ruth; Pomerantz, James R.; van der Helm, Peter A.; van Leeuwen, Cees

    2012-01-01

    Our first review paper on the occasion of the centennial anniversary of Gestalt psychology focused on perceptual grouping and figure-ground organization. It concluded that further progress requires a reconsideration of the conceptual and theoretical foundations of the Gestalt approach, which is provided here. In particular, we review contemporary formulations of holism within an information-processing framework, allowing for operational definitions (e.g., integral dimensions, emergent features, configural superiority, global precedence, primacy of holistic/configural properties) and a refined understanding of its psychological implications (e.g., at the level of attention, perception, and decision). We also review four lines of theoretical progress regarding the law of Prägnanz—the brain’s tendency of being attracted towards states corresponding to the simplest possible organization, given the available stimulation. The first considers the brain as a complex adaptive system and explains how self-organization solves the conundrum of trading between robustness and flexibility of perceptual states. The second specifies the economy principle in terms of optimization of neural resources, showing that elementary sensors working independently to minimize uncertainty can respond optimally at the system level. The third considers how Gestalt percepts (e.g., groups, objects) are optimal given the available stimulation, with optimality specified in Bayesian terms. Fourth, Structural Information Theory explains how a Gestaltist visual system that focuses on internal coding efficiency yields external veridicality as a side-effect. To answer the fundamental question of why things look as they do, a further synthesis of these complementary perspectives is required. PMID:22845750

  5. A century of Gestalt psychology in visual perception: II. Conceptual and theoretical foundations.

    Science.gov (United States)

    Wagemans, Johan; Feldman, Jacob; Gepshtein, Sergei; Kimchi, Ruth; Pomerantz, James R; van der Helm, Peter A; van Leeuwen, Cees

    2012-11-01

    Our first review article (Wagemans et al., 2012) on the occasion of the centennial anniversary of Gestalt psychology focused on perceptual grouping and figure-ground organization. It concluded that further progress requires a reconsideration of the conceptual and theoretical foundations of the Gestalt approach, which is provided here. In particular, we review contemporary formulations of holism within an information-processing framework, allowing for operational definitions (e.g., integral dimensions, emergent features, configural superiority, global precedence, primacy of holistic/configural properties) and a refined understanding of its psychological implications (e.g., at the level of attention, perception, and decision). We also review 4 lines of theoretical progress regarding the law of Prägnanz-the brain's tendency of being attracted towards states corresponding to the simplest possible organization, given the available stimulation. The first considers the brain as a complex adaptive system and explains how self-organization solves the conundrum of trading between robustness and flexibility of perceptual states. The second specifies the economy principle in terms of optimization of neural resources, showing that elementary sensors working independently to minimize uncertainty can respond optimally at the system level. The third considers how Gestalt percepts (e.g., groups, objects) are optimal given the available stimulation, with optimality specified in Bayesian terms. Fourth, structural information theory explains how a Gestaltist visual system that focuses on internal coding efficiency yields external veridicality as a side effect. To answer the fundamental question of why things look as they do, a further synthesis of these complementary perspectives is required.

  6. The results of STEM education methods in physics at the 11th grade level: Light and visual equipment lesson

    Science.gov (United States)

    Tungsombatsanti, A.; Ponkham, K.; Somtoa, T.

    2018-01-01

    This research aimed to: 1) To evaluate the efficiency of the process and the efficiency of the results (E1 / E2) of the innovative instructional lesson plan in the form of the STEM Education method in the field of physics of secondary students at the 10th grade level in physics class to determine the efficiency of the STEM based on criteria of the 70/70 standard level. 2) To study students' critical thinking skills of secondary students at the 11th grade level, and assessing skill in criteria 80 percentage 3) To compare learning achievements between students' pre-post testing after taught in STEM Education 4) To evaluate Student' Satisfaction after using STEM Education teaching by using mean compare to 5 points Likert Scale. The participant used were 40 students from grade 11 at Borabu School, Borabu District, Mahasarakham Province, semester 2, Academic year 2016. Tools used in this study consist of: 1) STEM Education plan about the force and laws of motion for grade 11 students of 1 schemes with total of 15 hours, 2) The test of critical think skills with essay type in amount of 30 items, 3) achievement test on Light and visual equipment with multiple-choice of 4 options of 30 items, 4) satisfaction learning with 5 Rating Scale of 16 items. The statistics used in data analysis were percentage, mean, standard deviation, and t-test (Dependent). The results showed that 1) The results of these findings revealed that the efficiency of the STEM based on criteria indicate that are higher than the standard level of the 70/70 at 71.51/75 2) Student has critical thinking scores that are higher than criteria 80 percentage as amount is 26 people. 3) Statistically significant of students' learning achievements to their later outcomes were differentiated between pretest and posttest at the .05 level, evidently. 4) The student' level of satisfaction toward the learning by using STEM Education plan was at a good level (X ¯ = 4.33, S.D = 0.64).

  7. Effects of oculo-motor exercise, functional electrical stimulation and proprioceptive neuromuscular stimulation on visual perception of spatial neglect patients.

    Science.gov (United States)

    Park, Si-Eun; Oh, Dae-Sik; Moon, Sang-Hyun

    2016-04-01

    [Purpose] The purpose of this study was to identify the effects of oculo-motor exercise, functional electrical stimulation (FES), and proprioceptive neuromuscular facilitation (PNF) on the visual perception of spatial neglect patients. [Subjects and Methods] The subjects were randomly allocated to 3 groups: an oculo-motor exercise (OME) group, a FES with oculo-motor exercise (FOME) group, and a PNF with oculo-motor exercise (POME) group. The line bisection test (LBT), motor free visual test (MVPT), and Catherine Bergego Scale (CBS) were used to measure visual perception. These were performed 5 times per week for 6 weeks. [Results] The OME group and POME group showed significant improvements according to the LBT and MVPT results, but the FOME group showed no significant improvement. According to the CBS, all 3 groups showed significant improvements. The OME and POME groups showed improvement over the FOME group in the LBT and MVPT. However, there was no significant difference among the three groups according to the CBS. [Conclusion] These results indicate that oculo-motor exercise and PNF with oculo-motor exercise had more positive effects than FES with oculo-motor exercise on the visual perception of spatial neglect patients.

  8. The Influence of Peer Tutors and Technology-Actuated Reading Instruction Process on Third-Grade Students' Self-Perceptions as Readers: A Multiple Case Study

    Science.gov (United States)

    Daw, Brenda Shill

    2011-01-01

    Driven by Lev Vygotsky's Sociocultural Theory (1986), my study investigated the self-perceptions and interactions of seven underperforming, third-grade readers while using Technology-Actuated Reading Instruction (TARI). Partnered with same-age peer tutors, readers used digital tools to listen to, read/record, and playback oral reading passages.…

  9. The effect of historical, non-fiction, trade books on third-grade students' perceptions of scientists

    Science.gov (United States)

    Farland, Donna Lynn

    Researchers do not know what, if any, specific influence such stereotypical images have on the shaping of children's perceptions in science (Schibeci & Sorenson, 1983), but the indications are that stereotypical images translate into negative perceptions of science. Commonly held stereotypic images are in direct opposition to what students should understand about science as identified by the National Science Education Standards (1996) in which learning about 'Science as a Human Endeavor' begins as early as grades K--4. Nationally, many schools are moving toward kit-based science instruction, which generally consists of a series of guided discovery activities that lead children toward description and understanding of scientific phenomena. It is proposed that by supplementing these kits with historical, non-fiction, trade books, children will gain a broader understanding of the diversity of scientists, their work, and the variety of places science is done. No studies, to date, have been conducted to examine students' understanding of the concepts included in 'Science as a Human Endeavor' as they receive kit-based science instruction. This research has been designed to answer the following question: Does the inclusion of historical, non-fiction, trade books, presenting scientists as people working with or developing an idea, as part of kit-based science instruction influence third grade students' representations of the contemporary scientist and his/her work? It was found that students who were read historical, non-fiction, trade books in conjunction with kit-based instruction demonstrated significant differences in their drawings of scientists from those produced by students who were not exposed to the trade books with respect to two criteria; appearance of scientists, and the activity performed by scientists. This study also revealed that students were able to maintain the improvement in their representations of scientists four weeks after the intervention had ended

  10. Large scale functional brain networks underlying temporal integration of audio-visual speech perception: An EEG study

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    G. Vinodh Kumar

    2016-10-01

    Full Text Available Observable lip movements of the speaker influence perception of auditory speech. A classical example of this influence is reported by listeners who perceive an illusory (cross-modal speech sound (McGurk-effect when presented with incongruent audio-visual (AV speech stimuli. Recent neuroimaging studies of AV speech perception accentuate the role of frontal, parietal and the integrative brain sites in the vicinity of the superior temporal sulcus (STS for multisensory speech perception. However, if and how does the network across the whole brain participates during multisensory perception processing remains an open question. We posit that a large-scale functional connectivity among the neural population situated in distributed brain sites may provide valuable insights involved in processing and fusing of AV speech. Varying the psychophysical parameters in tandem with electroencephalogram (EEG recordings, we exploited the trial-by-trial perceptual variability of incongruent audio-visual (AV speech stimuli to identify the characteristics of the large-scale cortical network that facilitates multisensory perception during synchronous and asynchronous AV speech. We evaluated the spectral landscape of EEG signals during multisensory speech perception at varying AV lags. Functional connectivity dynamics for all sensor pairs was computed using the time-frequency global coherence, the vector sum of pairwise coherence changes over time. During synchronous AV speech, we observed enhanced global gamma-band coherence and decreased alpha and beta-band coherence underlying cross-modal (illusory perception compared to unisensory perception around a temporal window of 300-600 ms following onset of stimuli. During asynchronous speech stimuli, a global broadband coherence was observed during cross-modal perception at earlier times along with pre-stimulus decreases of lower frequency power, e.g., alpha rhythms for positive AV lags and theta rhythms for negative AV

  11. The Nation's Report Card: Arts 2008--Music & Visual Arts. National Assessment of Educational Progress at Grade 8. NCES 2009-488

    Science.gov (United States)

    Keiper, S.; Sandene, B. A.; Persky, H. R.; Kuang, M.

    2009-01-01

    This report presents the results of the 2008 National Assessment of Educational Progress (NAEP) in the arts, which was given to a nationally representative sample of 7,900 eighth-grade public and private school students. Approximately one-half of these students were assessed in music, and the other half were assessed in visual arts. The Music…

  12. Perception of visual apparent motion is modulated by a gap within concurrent auditory glides, even when it is illusory

    Science.gov (United States)

    Wang, Qingcui; Guo, Lu; Bao, Ming; Chen, Lihan

    2015-01-01

    Auditory and visual events often happen concurrently, and how they group together can have a strong effect on what is perceived. We investigated whether/how intra- or cross-modal temporal grouping influenced the perceptual decision of otherwise ambiguous visual apparent motion. To achieve this, we juxtaposed auditory gap transfer illusion with visual Ternus display. The Ternus display involves a multi-element stimulus that can induce either of two different percepts of apparent motion: ‘element motion’ (EM) or ‘group motion’ (GM). In “EM,” the endmost disk is seen as moving back and forth while the middle disk at the central position remains stationary; while in “GM,” both disks appear to move laterally as a whole. The gap transfer illusion refers to the illusory subjective transfer of a short gap (around 100 ms) from the long glide to the short continuous glide when the two glides intercede at the temporal middle point. In our experiments, observers were required to make a perceptual discrimination of Ternus motion in the presence of concurrent auditory glides (with or without a gap inside). Results showed that a gap within a short glide imposed a remarkable effect on separating visual events, and led to a dominant perception of GM as well. The auditory configuration with gap transfer illusion triggered the same auditory capture effect. Further investigations showed that visual interval which coincided with the gap interval (50–230 ms) in the long glide was perceived to be shorter than that within both the short glide and the ‘gap-transfer’ auditory configurations in the same physical intervals (gaps). The results indicated that auditory temporal perceptual grouping takes priority over the cross-modal interaction in determining the final readout of the visual perception, and the mechanism of selective attention on auditory events also plays a role. PMID:26042055

  13. Subjective visual vertical perception in patients with vestibular neuritis and sudden sensorineural hearing loss.

    Science.gov (United States)

    Ogawa, Yasuo; Otsuka, Koji; Shimizu, Shigetaka; Inagaki, Taro; Kondo, Takahito; Suzuki, Mamoru

    2012-01-01

    To determine the subjective visual vertical (SVV) perception in patients with vestibular neuritis (VN) and sudden sensorineural hearing loss (SSHL) using the SVV test and other neuro-otological examinations, namely, the vestibular evoked myogenic potential (VEMP) and caloric tests, and to clarify which vestibular nerve function is associated with an SVV shift. We performed the SVV test in 36 VN patients and 80 SSHL patients. Thereafter, we investigated directional changes in the SVV in the VN and SSHL patients, and compared the results of the SVV test with those of the VEMP and caloric tests. Abnormal SVV (> 2° was found at a rate of 69.4% in the VN patients and 26.3% in the SSHL patients. In all except 1 VN patient, the SVV tilted to the lesion side. The rate of abnormal SVV was significantly higher in patients with complete canal paresis (CP) than in patients with partial CP. There was no significant relationship between the rates of abnormal SVV and VEMP. In the SSHL patients, neither the SVV nor the VEMP affected the hearing outcome and patients with abnormal VEMP tended to show abnormal SVV. VN patients showed a higher rate of abnormal SVV than SSHL patients. From the results, it is speculated that the superior vestibular nerve function mainly affects the SVV tilt, although the inferior vestibular nerve function may also have an effect.

  14. Comparison of visual grading and free-response ROC analyses for assessment of image-processing algorithms in digital mammography.

    Science.gov (United States)

    Zanca, F; Van Ongeval, C; Claus, F; Jacobs, J; Oyen, R; Bosmans, H

    2012-12-01

    To compare two methods for assessment of image-processing algorithms in digital mammography: free-response receiver operating characteristic (FROC) for the specific task of microcalcification detection and visual grading analysis (VGA). The FROC study was conducted prior to the VGA study reported here. 200 raw data files of low breast density (Breast Imaging-Reporting and Data System I-II) mammograms (Novation DR, Siemens, Germany)-100 of which abnormal-were processed by four image-processing algorithms: Raffaello (IMS, Bologna, Italy), Sigmoid (Sectra, Linköping, Sweden), and OpView v. 2 and v. 1 (Siemens, Erlangen, Germany). Four radiologists assessed the mammograms for the detection of microcalcifications. 8 months after the FROC study, a subset (200) of the 800 images was reinterpreted by the same radiologists, using the VGA methodology in a side-by-side approach. The VGA grading was based on noise, saturation, contrast, sharpness and confidence with the image in terms of normal structures. Ordinal logistic regression was applied; OpView v. 1 was the reference processing algorithm. In the FROC study all algorithms performed better than OpView v. 1. From the current VGA study and for confidence with the image, Sigmoid and Raffaello were significantly worse (pimage quality criteria, results were mixed; Raffaello and Sigmoid for example were better than OpView v. 1 for sharpness and contrast (although not always significantly). VGA and FROC discordant results should be attributed to the different clinical task addressed. The method to use for image-processing assessment depends on the clinical task tested.

  15. Bender-Gradual Scoring System (B-SPG: Analysis of the maturation of visual-motor perception of children

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    Lariana Paula Pinto

    2013-12-01

    Full Text Available This study aimed to investigate the maturational aspect of visual motor perception ability, assessed by Bender - Gradual Scoring System (B-SPG in relation to age and educational level. Analyses of variance were made between the total score and the punctuation received on each reproduction of the figures, being compared according to age and educational level. Participants were 361 students, of both genders, between 6 and 10 years, from 1st to 5th years of primary education from public and private schools. The total scores obtained in the test differed significantly in relation to age and educational level. Confirming the proposal of instrument, it became clear that the B-GSP proved to be sensitive to capture the maturational aspect of visual motor perception ability.

  16. Evaluation of the traffic parameters in a metropolitan area by fusing visual perceptions and CNN processing of webcam images.

    Science.gov (United States)

    Faro, Alberto; Giordano, Daniela; Spampinato, Concetto

    2008-06-01

    This paper proposes a traffic monitoring architecture based on a high-speed communication network whose nodes are equipped with fuzzy processors and cellular neural network (CNN) embedded systems. It implements a real-time mobility information system where visual human perceptions sent by people working on the territory and video-sequences of traffic taken from webcams are jointly processed to evaluate the fundamental traffic parameters for every street of a metropolitan area. This paper presents the whole methodology for data collection and analysis and compares the accuracy and the processing time of the proposed soft computing techniques with other existing algorithms. Moreover, this paper discusses when and why it is recommended to fuse the visual perceptions of the traffic with the automated measurements taken from the webcams to compute the maximum traveling time that is likely needed to reach any destination in the traffic network.

  17. Mechanical characterization of sawn timber for structural use, graded visually in accordance with Spanish standard UNE 56544

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    Fernández-Golfín, J. I.

    1998-12-01

    Full Text Available The employment of timber in structures in Spain was hurting of the nonexistence of accepted calculation procedures. The recent adoption and publication of the Eurocode 5 compels to the employment of the characteristic values of the material in the structural calculation by the method of the finite elements. This report sets forth the results of the experiments carried out at INIA's Forest Research Centre (CIFOR-INIA regarding the mechanical characterization of sawn timber of size 150x50x3.000 mm and the structural uses of "Pinus sylvestris, P. radiata and P. pinaster" from different Spanish provenances. The characteristic values and strength classes corresponding with the grades stated in the Spanish standard UNE 56544 are also provided. The report compares and analyses the results of these experiments, and presents the conclusions drawn from the different behaviour shown by the four species. An analysis of the Spanish standard for the visual grading of structural timber is carried out on the three species.

    El empleo de la madera en la construcción en España adolecía de la inexistencia de procedimientos de cálculo normalizados. La reciente adopción y publicación del Eurocódigo 5 obliga al empleo de los valores característicos del material en el cálculo estructural de la madera por el método de los elementos finitos. Se presentan los resultados de la caracterización mecánica de la madera aserrada de tamaño (150x50x3.000 mm y usos estructurales de "Pinus sylvestris, P. radiata y P. pinaster" de diferentes procedencias, llevada a cabo en el Centro de Investigación Forestal (CIFOR del INIA. Se aportan los valores característicos y clases de resistencia que corresponden a las clases de calidad definidas en la norma UNE 56544. Se efectúa una comparación y análisis de los resultados obtenidos, extrayendo conclusiones respecto del diferente comportamiento observado para las cuatro especies. Se analiza la adecuación de la

  18. The relation between in hand manipulation skills,and visual-motor integration skills with hand writing skills of students of grade one of primery schools in Tehran

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    Minoo Kalantari

    2012-10-01

    Full Text Available Background and Aim: Hand writing is one of the most important abilities that children can gain and use as one part of their duties during their schooling. Students should write fluently and fast to have good connection with school works and gain good grades in exams. It is clear that hand writing problems can influence on children’s other abilities, because this skill is declared often as a reflection of intelligence and although what they write is the same, students with bad hand writing gain lower grades than students with nice hand writing. Recognition of sub base items in this problem will be affective in assessment, intermediation and prevention programs for children who are suffering from this problem. This study is designed to appoint the relation between in hand manipulation skills and visual-motor integration skills with hand writing skills of students of grade one of primary schools in Tehran.Material & Methods: This study was a descriptive-analytic (sectional investigation. 139 students had been chosen by accident. Instruments which had been used in this study consisted of visual-motor integration test, hand writing quality checklist, chronometer and nine hole PEG test. After data collection, the results were analyzed.Results: The results indicate that visual- motor integration and in hand manipulation skills both are affective in children’s hand writing skills. Grades of girls and boys in visual-motor integration were significantly different. Mean grade of girls in this test was higher than boys, but these variants in hand manipulation skills were not significantly different. Also there was no significant different in handwriting speed and quality between boys and girls.Conclusion: The results indicate that by assessment of visual- motor integration skills and in hand manipulation skills we may be able to find more exact ways to prevent and treat children who are suffering from hand writing problems.

  19. Public perceptions of west-side forests: improving visual impact assessments and designing thinnings and harvests for scenic integrity

    Science.gov (United States)

    Robert G. Ribe

    2013-01-01

    Perceptions of public forests’ acceptability can be infl uenced by aesthetic qualities, at both broad and project levels, aff ecting managers’ social license to act. Legal and methodological issues related to measuring and managing forest aesthetics in NEPA and NFMA decision-making are discussed. It is argued that conventional visual impact assessments—using...

  20. Clinical Outcomes and Late Endocrine, Neurocognitive, and Visual Profiles of Proton Radiation for Pediatric Low-Grade Gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Greenberger, Benjamin A. [Harvard Medical School, Boston, Massachusetts (United States); Pulsifer, Margaret B. [Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts (United States); Ebb, David H. [Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts (United States); MacDonald, Shannon M. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Jones, Robin M. [Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts (United States); Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts (United States); Butler, William E. [Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts (United States); Huang, Mary S. [Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts (United States); Marcus, Karen J. [Department of Radiation Oncology, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Oberg, Jennifer A. [Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York (United States); Tarbell, Nancy J. [Harvard Medical School, Boston, Massachusetts (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Yock, Torunn I., E-mail: tyock@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2014-08-01

    Purpose/Objective(s): Primary low-grade gliomas are common brain tumors of childhood, many of which require radiation therapy (RT) as definitive treatment. Increased conformality of RT could decrease the incidence and severity of late effects. We report our experience with 32 pediatric patients treated with proton RT. Methods and Materials: Thirty-two pediatric patients with low-grade gliomas of the brain or spinal cord were treated with proton RT from 1995 to 2007. Sixteen patients received at least 1 regimen of chemotherapy before definitive RT. The median radiation dose was 52.2 Gy{sub RBE} (48.6-54 Gy{sub RBE}). Results: The median age at treatment was 11.0 years (range, 2.7-21.5 years), with a median follow-up time of 7.6 years (range, 3.2-18.2 years). The 6-year and 8-year rates of progression-free survival were 89.7% and 82.8%, respectively, with an 8-year overall survival of 100%. For the subset of patients who received serial neurocognitive testing, there were no significant declines in Full-Scale Intelligence Quotient (P=.80), with a median neurocognitive testing interval of 4.5 years (range, 1.2-8.1 years) from baseline to follow-up, but subgroup analysis indicated some significant decline in neurocognitive outcomes for young children (<7 years) and those with significant dose to the left temporal lobe/hippocampus. The incidence of endocrinopathy correlated with a mean dose of ≥40 Gy{sub RBE} to the hypothalamus, pituitary, or optic chiasm. Stabilization or improvement of visual acuity was achieved in 83.3% of patients at risk for radiation-induced injury to the optic pathways. Conclusions: This report of late effects in children with low-grade gliomas after proton RT is encouraging. Proton RT appears to be associated with good clinical outcome, especially when the tumor location allows for increased sparing of the left temporal lobe, hippocampus, and hypothalamic-pituitary axis.

  1. Clinical Outcomes and Late Endocrine, Neurocognitive, and Visual Profiles of Proton Radiation for Pediatric Low-Grade Gliomas

    International Nuclear Information System (INIS)

    Greenberger, Benjamin A.; Pulsifer, Margaret B.; Ebb, David H.; MacDonald, Shannon M.; Jones, Robin M.; Butler, William E.; Huang, Mary S.; Marcus, Karen J.; Oberg, Jennifer A.; Tarbell, Nancy J.; Yock, Torunn I.

    2014-01-01

    Purpose/Objective(s): Primary low-grade gliomas are common brain tumors of childhood, many of which require radiation therapy (RT) as definitive treatment. Increased conformality of RT could decrease the incidence and severity of late effects. We report our experience with 32 pediatric patients treated with proton RT. Methods and Materials: Thirty-two pediatric patients with low-grade gliomas of the brain or spinal cord were treated with proton RT from 1995 to 2007. Sixteen patients received at least 1 regimen of chemotherapy before definitive RT. The median radiation dose was 52.2 Gy RBE (48.6-54 Gy RBE ). Results: The median age at treatment was 11.0 years (range, 2.7-21.5 years), with a median follow-up time of 7.6 years (range, 3.2-18.2 years). The 6-year and 8-year rates of progression-free survival were 89.7% and 82.8%, respectively, with an 8-year overall survival of 100%. For the subset of patients who received serial neurocognitive testing, there were no significant declines in Full-Scale Intelligence Quotient (P=.80), with a median neurocognitive testing interval of 4.5 years (range, 1.2-8.1 years) from baseline to follow-up, but subgroup analysis indicated some significant decline in neurocognitive outcomes for young children (<7 years) and those with significant dose to the left temporal lobe/hippocampus. The incidence of endocrinopathy correlated with a mean dose of ≥40 Gy RBE to the hypothalamus, pituitary, or optic chiasm. Stabilization or improvement of visual acuity was achieved in 83.3% of patients at risk for radiation-induced injury to the optic pathways. Conclusions: This report of late effects in children with low-grade gliomas after proton RT is encouraging. Proton RT appears to be associated with good clinical outcome, especially when the tumor location allows for increased sparing of the left temporal lobe, hippocampus, and hypothalamic-pituitary axis

  2. Visual and auditory socio-cognitive perception in unilateral temporal lobe epilepsy in children and adolescents: a prospective controlled study.

    Science.gov (United States)

    Laurent, Agathe; Arzimanoglou, Alexis; Panagiotakaki, Eleni; Sfaello, Ignacio; Kahane, Philippe; Ryvlin, Philippe; Hirsch, Edouard; de Schonen, Scania

    2014-12-01

    A high rate of abnormal social behavioural traits or perceptual deficits is observed in children with unilateral temporal lobe epilepsy. In the present study, perception of auditory and visual social signals, carried by faces and voices, was evaluated in children or adolescents with temporal lobe epilepsy. We prospectively investigated a sample of 62 children with focal non-idiopathic epilepsy early in the course of the disorder. The present analysis included 39 children with a confirmed diagnosis of temporal lobe epilepsy. Control participants (72), distributed across 10 age groups, served as a control group. Our socio-perceptual evaluation protocol comprised three socio-visual tasks (face identity, facial emotion and gaze direction recognition), two socio-auditory tasks (voice identity and emotional prosody recognition), and three control tasks (lip reading, geometrical pattern and linguistic intonation recognition). All 39 patients also benefited from a neuropsychological examination. As a group, children with temporal lobe epilepsy performed at a significantly lower level compared to the control group with regards to recognition of facial identity, direction of eye gaze, and emotional facial expressions. We found no relationship between the type of visual deficit and age at first seizure, duration of epilepsy, or the epilepsy-affected cerebral hemisphere. Deficits in socio-perceptual tasks could be found independently of the presence of deficits in visual or auditory episodic memory, visual non-facial pattern processing (control tasks), or speech perception. A normal FSIQ did not exempt some of the patients from an underlying deficit in some of the socio-perceptual tasks. Temporal lobe epilepsy not only impairs development of emotion recognition, but can also impair development of perception of other socio-perceptual signals in children with or without intellectual deficiency. Prospective studies need to be designed to evaluate the results of appropriate re

  3. Auditory, Visual, and Auditory-Visual Speech Perception by Individuals with Cochlear Implants versus Individuals with Hearing Aids

    Science.gov (United States)

    Most, Tova; Rothem, Hilla; Luntz, Michal

    2009-01-01

    The researchers evaluated the contribution of cochlear implants (CIs) to speech perception by a sample of prelingually deaf individuals implanted after age 8 years. This group was compared with a group with profound hearing impairment (HA-P), and with a group with severe hearing impairment (HA-S), both of which used hearing aids. Words and…

  4. Auditory, Visual, and Auditory-Visual Perceptions of Emotions by Young Children with Hearing Loss versus Children with Normal Hearing

    Science.gov (United States)

    Most, Tova; Michaelis, Hilit

    2012-01-01

    Purpose: This study aimed to investigate the effect of hearing loss (HL) on emotion-perception ability among young children with and without HL. Method: A total of 26 children 4.0-6.6 years of age with prelingual sensory-neural HL ranging from moderate to profound and 14 children with normal hearing (NH) participated. They were asked to identify…

  5. Visual thinking networking promotes long-term meaningful learning and achievement for 9th grade earth science students

    Science.gov (United States)

    Longo, Palma Joni

    2001-12-01

    An experimental and interview-based design was used to test the efficacy of visual thinking networking (VTN), a new generation of metacognitive learning strategies. Students constructed network diagrams using semantic and figural elements to represent knowledge relationships. The findings indicated the importance of using color in VTN strategies. The use of color promoted the encoding and reconstruction of earth science knowledge in memory and enhanced higher order thinking skills of problem solving. Fifty-six ninth grade earth science students (13--15 years of age) in a suburban school district outside New York City were randomly assigned to three classes with the same instructor. Five major positive findings emerged in the areas of problem solving achievement, organization of knowledge in memory, problem solving strategy dimensionality, conceptual understanding, and gender differences. A multi-covariate analysis was conducted on the pre-post gain scores of the AGI/NSTA Earth Science Examination (Part 1). Students who used the color VTN strategies had a significantly higher mean gain score on the problem solving criterion test items than students who used the black/white VTN (p = .003) and the writing strategies for learning science (p Gender influenced the choice of VTN strategy. Females used significantly more color VTN strategies, while males used predominately black/white VTN strategies (p = .01). A neurocognitive model, the encoding activation theory of the anterior cingulate (ENACT-AC), is proposed as an explanation for these findings.

  6. INFLUENCE OF CHOLINE ALFOSCERATE ON VISUAL PERCEPTION IN PATIENTS WITH AMBLYOPIA

    OpenAIRE

    I.E. Aznauryan; I.S. Bagrova

    2006-01-01

    Amblyopia is a frequent disorder in pediatric ophthalmology. The term of amblyopia refers to reduced vision caused by limited visual sensory stimulation (visual deprivation) at a time of visual system development, so the vision can not be improved by proper sunglasses. Apparatus treatment of amblyopia have limited effect in rehabilitation of children with moderate (lens corrected visual acuity between 0.2 and 0.3) and severe (lens corrected visual acuity below 0.2) amblyopia. Novel data conce...

  7. Understanding Teacher Perceptions in a Professional Development Program for a Middle Grade Science

    Science.gov (United States)

    Deloney, Dericka B.

    The standards-based framework requires teachers to evaluate and in some cases change their instructional approach to more student-centered and inquiry-based in an effort to help students meet the standards. The rationale for this study was to determine the skills needed for teachers to be effective in a standard-based, problem-based learning (PBL) constructivist classroom. Traditionally, teachers in this school district transitioning from teacher to student-centered classrooms need new skills when implementing this type of instruction. A qualitative case study design served to highlight the research questions for this project study. The participants in this study participated in data collection activities that include a multiple-choice survey, an interview, and the sharing of their PBL units. Artifacts, professional development teaching resources, from the workshop added credence to the survey and interview responses. The findings from each research question addressed the teachers' perception of their understanding and the obstacles of instructional design, development, and implementation the participants encountered. The results of this study indicated that teachers had problems with designing and implementing this instructional strategy due to lack of time and resources. This data assisted the development of district specific PBL sustainable professional development program that could be adaptable to other curriculums and school systems. Social change resulting from this study could include a framework for developing K-12 professional development as well as instructional programs that incorporates PBL curriculum design to enhance the student's inquiry, problem-solving, and decision-making skills that in turn should change their academic achievement and scores on high stakes test in science.

  8. Local visual perception bias in children with high-functioning autism spectrum disorders; do we have the whole picture?

    Science.gov (United States)

    Falkmer, Marita; Black, Melissa; Tang, Julia; Fitzgerald, Patrick; Girdler, Sonya; Leung, Denise; Ordqvist, Anna; Tan, Tele; Jahan, Ishrat; Falkmer, Torbjorn

    2016-01-01

    While local bias in visual processing in children with autism spectrum disorders (ASD) has been reported to result in difficulties in recognizing faces and facially expressed emotions, but superior ability in disembedding figures, associations between these abilities within a group of children with and without ASD have not been explored. Possible associations in performance on the Visual Perception Skills Figure-Ground test, a face recognition test and an emotion recognition test were investigated within 25 8-12-years-old children with high-functioning autism/Asperger syndrome, and in comparison to 33 typically developing children. Analyses indicated a weak positive correlation between accuracy in Figure-Ground recognition and emotion recognition. No other correlation estimates were significant. These findings challenge both the enhanced perceptual function hypothesis and the weak central coherence hypothesis, and accentuate the importance of further scrutinizing the existance and nature of local visual bias in ASD.

  9. Light pollution in ultraviolet and visible spectrum: effect on different visual perceptions.

    Directory of Open Access Journals (Sweden)

    Héctor Antonio Solano Lamphar

    Full Text Available In general terms, lighting research has been focused in the development of artificial light with the purpose of saving energy and having more durable lamps. However, the consequences that artificial night lighting could bring to the human being and living organisms have become an important issue recently. Light pollution represents a significant problem to both the environment and human health causing a disruption of biological rhythms related not only to the visible spectrum, but also to other parts of the electromagnetic spectrum. Since the lamps emit across a wide range of the electromagnetic spectrum, all photobiological species may be exposed to another type of light pollution. By comparing five different lamps, the present study attempts to evaluate UV radiative fluxes relative to what humans and two species of insects perceive as sky glow level. We have analyzed three atmospheric situations: clear sky, overcast sky and evolving precipitable water content. One important finding suggests that when a constant illuminance of urban spaces has to be guaranteed the sky glow from the low pressure sodium lamps has the most significant effect to the visual perception of the insects tested. But having the fixed number of luminaires the situation changes and the low pressure sodium lamp would be the best choice for all three species. The sky glow effects can be interpreted correctly only if the lamp types and the required amount of scotopic luxes at the ground are taken into account simultaneously. If these two factors are combined properly, then the ecological consequences of sky glow can be partly reduced. The results of this research may be equally useful for lighting engineers, architects, biologists and researchers who are studying the effects of sky glow on humans and biodiversity.

  10. The Conductor As Visual Guide: Gesture and Perception of Musical Content.

    Science.gov (United States)

    Kumar, Anita B; Morrison, Steven J

    2016-01-01

    Ensemble conductors are often described as embodying the music. Researchers have determined that expressive gestures affect viewers' perceptions of conducted ensemble performances. This effect may be due, in part, to conductor gesture delineating and amplifying specific expressive aspects of music performances. The purpose of the present study was to determine if conductor gesture affected observers' focus of attention to contrasting aspects of ensemble performances. Audio recordings of two different music excerpts featuring two-part counterpoint (an ostinato paired with a lyric melody, and long chord tones paired with rhythmic interjections) were paired with video of two conductors. Each conductor used gesture appropriate to one or the other musical element (e.g., connected and flowing or detached and crisp) for a total of sixteen videos. Musician participants evaluated 8 of the excerpts for Articulation, Rhythm, Style, and Phrasing using four 10-point differential scales anchored by descriptive terms (e.g., disconnected to connected, and angular to flowing.) Results indicated a relationship between gesture and listeners' evaluations of musical content. Listeners appear to be sensitive to the manner in which a conductor's gesture delineates musical lines, particularly as an indication of overall articulation and style. This effect was observed for the lyric melody and ostinato excerpt, but not for the chords and interjections excerpt. Therefore, this effect appears to be mitigated by the congruence of gesture to preconceptions of the importance of melodic over rhythmic material, of certain instrument timbres over others, and of length between onsets of active material. These results add to a body of literature that supports the importance of the visual component in the multimodal experience of music performance.

  11. The Conductor As Visual Guide: Gesture and Perception of Musical Content

    Science.gov (United States)

    Kumar, Anita B.; Morrison, Steven J.

    2016-01-01

    Ensemble conductors are often described as embodying the music. Researchers have determined that expressive gestures affect viewers’ perceptions of conducted ensemble performances. This effect may be due, in part, to conductor gesture delineating and amplifying specific expressive aspects of music performances. The purpose of the present study was to determine if conductor gesture affected observers’ focus of attention to contrasting aspects of ensemble performances. Audio recordings of two different music excerpts featuring two-part counterpoint (an ostinato paired with a lyric melody, and long chord tones paired with rhythmic interjections) were paired with video of two conductors. Each conductor used gesture appropriate to one or the other musical element (e.g., connected and flowing or detached and crisp) for a total of sixteen videos. Musician participants evaluated 8 of the excerpts for Articulation, Rhythm, Style, and Phrasing using four 10-point differential scales anchored by descriptive terms (e.g., disconnected to connected, and angular to flowing.) Results indicated a relationship between gesture and listeners’ evaluations of musical content. Listeners appear to be sensitive to the manner in which a conductor’s gesture delineates musical lines, particularly as an indication of overall articulation and style. This effect was observed for the lyric melody and ostinato excerpt, but not for the chords and interjections excerpt. Therefore, this effect appears to be mitigated by the congruence of gesture to preconceptions of the importance of melodic over rhythmic material, of certain instrument timbres over others, and of length between onsets of active material. These results add to a body of literature that supports the importance of the visual component in the multimodal experience of music performance. PMID:27458425

  12. Light pollution in ultraviolet and visible spectrum: effect on different visual perceptions.

    Science.gov (United States)

    Solano Lamphar, Héctor Antonio; Kocifaj, Miroslav

    2013-01-01

    In general terms, lighting research has been focused in the development of artificial light with the purpose of saving energy and having more durable lamps. However, the consequences that artificial night lighting could bring to the human being and living organisms have become an important issue recently. Light pollution represents a significant problem to both the environment and human health causing a disruption of biological rhythms related not only to the visible spectrum, but also to other parts of the electromagnetic spectrum. Since the lamps emit across a wide range of the electromagnetic spectrum, all photobiological species may be exposed to another type of light pollution. By comparing five different lamps, the present study attempts to evaluate UV radiative fluxes relative to what humans and two species of insects perceive as sky glow level. We have analyzed three atmospheric situations: clear sky, overcast sky and evolving precipitable water content. One important finding suggests that when a constant illuminance of urban spaces has to be guaranteed the sky glow from the low pressure sodium lamps has the most significant effect to the visual perception of the insects tested. But having the fixed number of luminaires the situation changes and the low pressure sodium lamp would be the best choice for all three species. The sky glow effects can be interpreted correctly only if the lamp types and the required amount of scotopic luxes at the ground are taken into account simultaneously. If these two factors are combined properly, then the ecological consequences of sky glow can be partly reduced. The results of this research may be equally useful for lighting engineers, architects, biologists and researchers who are studying the effects of sky glow on humans and biodiversity.

  13. Refining Stimulus Parameters in Assessing Infant Speech Perception Using Visual Reinforcement Infant Speech Discrimination: Sensation Level.

    Science.gov (United States)

    Uhler, Kristin M; Baca, Rosalinda; Dudas, Emily; Fredrickson, Tammy

    2015-01-01

    Speech perception measures have long been considered an integral piece of the audiological assessment battery. Currently, a prelinguistic, standardized measure of speech perception is missing in the clinical assessment battery for infants and young toddlers. Such a measure would allow systematic assessment of speech perception abilities of infants as well as the potential to investigate the impact early identification of hearing loss and early fitting of amplification have on the auditory pathways. To investigate the impact of sensation level (SL) on the ability of infants with normal hearing (NH) to discriminate /a-i/ and /ba-da/ and to determine if performance on the two contrasts are significantly different in predicting the discrimination criterion. The design was based on a survival analysis model for event occurrence and a repeated measures logistic model for binary outcomes. The outcome for survival analysis was the minimum SL for criterion and the outcome for the logistic regression model was the presence/absence of achieving the criterion. Criterion achievement was designated when an infant's proportion correct score was >0.75 on the discrimination performance task. Twenty-two infants with NH sensitivity participated in this study. There were 9 males and 13 females, aged 6-14 mo. Testing took place over two to three sessions. The first session consisted of a hearing test, threshold assessment of the two speech sounds (/a/ and /i/), and if time and attention allowed, visual reinforcement infant speech discrimination (VRISD). The second session consisted of VRISD assessment for the two test contrasts (/a-i/ and /ba-da/). The presentation level started at 50 dBA. If the infant was unable to successfully achieve criterion (>0.75) at 50 dBA, the presentation level was increased to 70 dBA followed by 60 dBA. Data examination included an event analysis, which provided the probability of criterion distribution across SL. The second stage of the analysis was a

  14. Quality-Related Monitoring and Grading of Granulated Products by Weibull-Distribution Modeling of Visual Images with Semi-Supervised Learning.

    Science.gov (United States)

    Liu, Jinping; Tang, Zhaohui; Xu, Pengfei; Liu, Wenzhong; Zhang, Jin; Zhu, Jianyong

    2016-06-29

    The topic of online product quality inspection (OPQI) with smart visual sensors is attracting increasing interest in both the academic and industrial communities on account of the natural connection between the visual appearance of products with their underlying qualities. Visual images captured from granulated products (GPs), e.g., cereal products, fabric textiles, are comprised of a large number of independent particles or stochastically stacking locally homogeneous fragments, whose analysis and understanding remains challenging. A method of image statistical modeling-based OPQI for GP quality grading and monitoring by a Weibull distribution(WD) model with a semi-supervised learning classifier is presented. WD-model parameters (WD-MPs) of GP images' spatial structures, obtained with omnidirectional Gaussian derivative filtering (OGDF), which were demonstrated theoretically to obey a specific WD model of integral form, were extracted as the visual features. Then, a co-training-style semi-supervised classifier algorithm, named COSC-Boosting, was exploited for semi-supervised GP quality grading, by integrating two independent classifiers with complementary nature in the face of scarce labeled samples. Effectiveness of the proposed OPQI method was verified and compared in the field of automated rice quality grading with commonly-used methods and showed superior performance, which lays a foundation for the quality control of GP on assembly lines.

  15. Visual perception from the perspective of a representational, non-reductionistic, level-dependent account of perception and conscious awareness

    DEFF Research Database (Denmark)

    Overgaard, Morten; Mogensen, Jesper

    2014-01-01

    This article proposes a new model to interpret seemingly conflicting evidence concerning the correlation of consciousness and neural processes. Based on an analysis of research of blindsight and subliminal perception, the reorganization of elementary functions and consciousness framework suggests...... partly by too coarse-grained methodology, and partly by top-down enhancing of representations that normally would not be relevant to action....

  16. Mirror Neurons in Monkey Premotor Area F5 Show Tuning for Critical Features of Visual Causality Perception.

    Science.gov (United States)

    Caggiano, Vittorio; Fleischer, Falk; Pomper, Joern K; Giese, Martin A; Thier, Peter

    2016-11-21

    Humans derive causality judgments reliably from highly abstract stimuli, such as moving discs that bump into each other [1]. This fascinating visual capability emerges gradually during human development [2], perhaps as consequence of sensorimotor experience [3]. Human functional imaging studies suggest an involvement of the "action observation network" in the processing of such stimuli [4, 5]. In addition, theoretical studies suggest a link between the computational mechanisms of action and causality perception [6, 7], consistent with the fact that both functions require an analysis of sequences of spatiotemporal relationships between interacting stimulus elements. Single-cell correlates of the perception of causality are completely unknown. In order to find such neural correlates, we investigated the responses of "mirror neurons" in macaque premotor area F5 [8, 9]. These neurons respond during the observation as well as during the execution of actions and show interesting invariances, e.g., with respect to the stimulus view [10], occlusions [11], or whether an action is really executed or suppressed [12]. We investigated the spatiotemporal properties of the visual responses of mirror neurons to naturalistic hand action stimuli and to abstract stimuli, which specified the same causal relationships. We found a high degree of generalization between these two stimulus classes. In addition, many features that strongly reduced the similarity of the response patterns coincided with the ones that also destroy the perception of causality in humans. This implies an overlap of neural structures involved in the processing of actions and the visual perception of causality at the single-cell level. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. The Effects of Apomorphine on Visual Perception in Patients With Parkinson Disease and Visual Hallucinations : A Pilot Study

    NARCIS (Netherlands)

    Geerligs, Linda; Meppelink, Anne Marthe; Brouwer, Wiebo H.; van Laar, Teus

    2009-01-01

    Visual hallucinations (VHs) often occur in patients with advanced Parkinson disease (PD). Overstimulation of dopamine receptors has been considered as one of the causes for VHs in PD. However, several clinical studies suggested that apomorphine infusion did not worsen existing VHs in PD, but could

  18. How Strong Is Your Coffee? The Influence of Visual Metaphors and Textual Claims on Consumers’ Flavor Perception and Product Evaluation

    Science.gov (United States)

    Fenko, Anna; de Vries, Roxan; van Rompay, Thomas

    2018-01-01

    This study investigates the relative impact of textual claims and visual metaphors displayed on the product’s package on consumers’ flavor experience and product evaluation. For consumers, strength is one of the most important sensory attributes of coffee. The 2 × 3 between-subjects experiment (N = 123) compared the effects of visual metaphor of strength (an image of a lion located either on top or on the bottom of the package of coffee beans) and the direct textual claim (“extra strong”) on consumers’ responses to coffee, including product expectation, flavor evaluation, strength perception and purchase intention. The results demonstrate that both the textual claim and the visual metaphor can be efficient in communicating the product attribute of strength. The presence of the image positively influenced consumers’ product expectations before tasting. The textual claim increased the perception of strength of coffee and the purchase intention of the product. The location of the image also played an important role in flavor perception and purchase intention. The image located on the bottom of the package increased the perceived strength of coffee and purchase intention of the product compared to the image on top of the package. This result could be interpreted from the perspective of the grounded cognition theory, which suggests that a picture in the lower part of the package would automatically activate the “strong is heavy” metaphor. As heavy objects are usually associated with a position on the ground, this would explain why perceiving a visually heavy package would lead to the experience of a strong coffee. Further research is needed to better understand the relationships between a metaphorical image and its spatial position in food packaging design. PMID:29459840

  19. Why people see things that are not there: a novel Perception and Attention Deficit model for recurrent complex visual hallucinations.

    Science.gov (United States)

    Collerton, Daniel; Perry, Elaine; McKeith, Ian

    2005-12-01

    As many as two million people in the United Kingdom repeatedly see people, animals, and objects that have no objective reality. Hallucinations on the border of sleep, dementing illnesses, delirium, eye disease, and schizophrenia account for 90% of these. The remainder have rarer disorders. We review existing models of recurrent complex visual hallucinations (RCVH) in the awake person, including cortical irritation, cortical hyperexcitability and cortical release, top-down activation, misperception, dream intrusion, and interactive models. We provide evidence that these can neither fully account for the phenomenology of RCVH, nor for variations in the frequency of RCVH in different disorders. We propose a novel Perception and Attention Deficit (PAD) model for RCVH. A combination of impaired attentional binding and poor sensory activation of a correct proto-object, in conjunction with a relatively intact scene representation, bias perception to allow the intrusion of a hallucinatory proto-object into a scene perception. Incorporation of this image into a context-specific hallucinatory scene representation accounts for repetitive hallucinations. We suggest that these impairments are underpinned by disturbances in a lateral frontal cortex-ventral visual stream system. We show how the frequency of RCVH in different diseases is related to the coexistence of attentional and visual perceptual impairments; how attentional and perceptual processes can account for their phenomenology; and that diseases and other states with high rates of RCVH have cholinergic dysfunction in both frontal cortex and the ventral visual stream. Several tests of the model are indicated, together with a number of treatment options that it generates.

  20. How Strong Is Your Coffee? The Influence of Visual Metaphors and Textual Claims on Consumers’ Flavor Perception and Product Evaluation

    Directory of Open Access Journals (Sweden)

    Anna Fenko

    2018-02-01

    Full Text Available This study investigates the relative impact of textual claims and visual metaphors displayed on the product’s package on consumers’ flavor experience and product evaluation. For consumers, strength is one of the most important sensory attributes of coffee. The 2 × 3 between-subjects experiment (N = 123 compared the effects of visual metaphor of strength (an image of a lion located either on top or on the bottom of the package of coffee beans and the direct textual claim (“extra strong” on consumers’ responses to coffee, including product expectation, flavor evaluation, strength perception and purchase intention. The results demonstrate that both the textual claim and the visual metaphor can be efficient in communicating the product attribute of strength. The presence of the image positively influenced consumers’ product expectations before tasting. The textual claim increased the perception of strength of coffee and the purchase intention of the product. The location of the image also played an important role in flavor perception and purchase intention. The image located on the bottom of the package increased the perceived strength of coffee and purchase intention of the product compared to the image on top of the package. This result could be interpreted from the perspective of the grounded cognition theory, which suggests that a picture in the lower part of the package would automatically activate the “strong is heavy” metaphor. As heavy objects are usually associated with a position on the ground, this would explain why perceiving a visually heavy package would lead to the experience of a strong coffee. Further research is needed to better understand the relationships between a metaphorical image and its spatial position in food packaging design.

  1. How Strong Is Your Coffee? The Influence of Visual Metaphors and Textual Claims on Consumers' Flavor Perception and Product Evaluation.

    Science.gov (United States)

    Fenko, Anna; de Vries, Roxan; van Rompay, Thomas

    2018-01-01

    This study investigates the relative impact of textual claims and visual metaphors displayed on the product's package on consumers' flavor experience and product evaluation. For consumers, strength is one of the most important sensory attributes of coffee. The 2 × 3 between-subjects experiment ( N = 123) compared the effects of visual metaphor of strength (an image of a lion located either on top or on the bottom of the package of coffee beans) and the direct textual claim ("extra strong") on consumers' responses to coffee, including product expectation, flavor evaluation, strength perception and purchase intention. The results demonstrate that both the textual claim and the visual metaphor can be efficient in communicating the product attribute of strength. The presence of the image positively influenced consumers' product expectations before tasting. The textual claim increased the perception of strength of coffee and the purchase intention of the product. The location of the image also played an important role in flavor perception and purchase intention. The image located on the bottom of the package increased the perceived strength of coffee and purchase intention of the product compared to the image on top of the package. This result could be interpreted from the perspective of the grounded cognition theory, which suggests that a picture in the lower part of the package would automatically activate the "strong is heavy" metaphor. As heavy objects are usually associated with a position on the ground, this would explain why perceiving a visually heavy package would lead to the experience of a strong coffee. Further research is needed to better understand the relationships between a metaphorical image and its spatial position in food packaging design.

  2. Reinforcement of perceptual inference: reward and punishment alter conscious visual perception during binocular rivalry

    Directory of Open Access Journals (Sweden)

    Gregor eWilbertz

    2014-12-01

    Full Text Available Perception is an inferential process, which becomes immediately evident when sensory information is conflicting or ambiguous and thus allows for more than one perceptual interpretation. Thinking the idea of perception as inference through to the end results in a blurring of boundaries between perception and action selection, as perceptual inference implies the construction of a percept as an active process. Here we therefore wondered whether perception shares a key characteristic of action selection, namely that it is shaped by reinforcement learning. In two behavioral experiments, we used binocular rivalry to examine whether perceptual inference can be influenced by the association of perceptual outcomes with reward or punishment, respectively, in analogy to instrumental conditioning. Binocular rivalry was evoked by two orthogonal grating stimuli presented to the two eyes, resulting in perceptual alternations between the two gratings. Perception was tracked indirectly and objectively through a target detection task, which allowed us to preclude potential reporting biases. Monetary rewards or punishments were given repeatedly during perception of only one of the two rivalling stimuli. We found an increase in dominance durations for the percept associated with reward, relative to the non-rewarded percept. In contrast, punishment led to an increase of the non-punished compared to a relative decrease of the punished percept. Our results show that perception shares key characteristics with action selection, in that it is influenced by reward and punishment in opposite directions, thus narrowing the gap between the conceptually separated domains of perception and action selection. We conclude that perceptual inference is an adaptive process that is shaped by its consequences.

  3. Continued use of an interactive computer game-based visual perception learning system in children with developmental delay.

    Science.gov (United States)

    Lin, Hsien-Cheng; Chiu, Yu-Hsien; Chen, Yenming J; Wuang, Yee-Pay; Chen, Chiu-Ping; Wang, Chih-Chung; Huang, Chien-Ling; Wu, Tang-Meng; Ho, Wen-Hsien

    2017-11-01

    This study developed an interactive computer game-based visual perception learning system for special education children with developmental delay. To investigate whether perceived interactivity affects continued use of the system, this study developed a theoretical model of the process in which learners decide whether to continue using an interactive computer game-based visual perception learning system. The technology acceptance model, which considers perceived ease of use, perceived usefulness, and perceived playfulness, was extended by integrating perceived interaction (i.e., learner-instructor interaction and learner-system interaction) and then analyzing the effects of these perceptions on satisfaction and continued use. Data were collected from 150 participants (rehabilitation therapists, medical paraprofessionals, and parents of children with developmental delay) recruited from a single medical center in Taiwan. Structural equation modeling and partial-least-squares techniques were used to evaluate relationships within the model. The modeling results indicated that both perceived ease of use and perceived usefulness were positively associated with both learner-instructor interaction and learner-system interaction. However, perceived playfulness only had a positive association with learner-system interaction and not with learner-instructor interaction. Moreover, satisfaction was positively affected by perceived ease of use, perceived usefulness, and perceived playfulness. Thus, satisfaction positively affects continued use of the system. The data obtained by this study can be applied by researchers, designers of computer game-based learning systems, special education workers, and medical professionals. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Determining student teachers' perceptions on using technology via Likert scale, visual association test and metaphors: A mixed study

    Directory of Open Access Journals (Sweden)

    Mevhibe Kobak

    2013-04-01

    Full Text Available The aim of this study is to determine senior student teachers’ perceptions on using technology by approaching various points of view. In this study, researchers collected data through Technology Perceptions Scale, Visual Association Activity and Technology Metaphors. The participants of the study were 104 senior student teachers who were enrolled in Balıkesir University Necatibey Faculty of Education. In this descriptive study, researchers interpreted qualitative data in conjunction with quantitative data. Based on the data obtained, even though student teachers’ perceptions on using technology were found positive in the light of Likert scale, there was no significant relation in terms of gender and enrolled undergraduate program. According to the results of visual association test, student teachers ranked smartboard, Internet and computer in the first three, and portable media player, mobile phone and video/camera in the last three. Besides, researchers analyzed and classified student teachers’ metaphors about technology under 9 categories: 1developing-changing technology, 2rapidly progressing technology, 3 limitless-endless technology, 4beneficial technology, 5harmful technology, 6both beneficial and harmful technology, 7indispensible technology, 8technology as a necessity, 9 all-inclusive technology. At the end of the study, those nine categories which were acquired using the content analysis technique are presented in a table which shows the interaction between categories in a holistic view.

  5. Atypical audio-visual speech perception and McGurk effects in children with specific language impairment.

    Science.gov (United States)

    Leybaert, Jacqueline; Macchi, Lucie; Huyse, Aurélie; Champoux, François; Bayard, Clémence; Colin, Cécile; Berthommier, Frédéric

    2014-01-01

    Audiovisual speech perception of children with specific language impairment (SLI) and children with typical language development (TLD) was compared in two experiments using /aCa/ syllables presented in the context of a masking release paradigm. Children had to repeat syllables presented in auditory alone, visual alone (speechreading), audiovisual congruent and incongruent (McGurk) conditions. Stimuli were masked by either stationary (ST) or amplitude modulated (AM) noise. Although children with SLI were less accurate in auditory and audiovisual speech perception, they showed similar auditory masking release effect than children with TLD. Children with SLI also had less correct responses in speechreading than children with TLD, indicating impairment in phonemic processing of visual speech information. In response to McGurk stimuli, children with TLD showed more fusions in AM noise than in ST noise, a consequence of the auditory masking release effect and of the influence of visual information. Children with SLI did not show this effect systematically, suggesting they were less influenced by visual speech. However, when the visual cues were easily identified, the profile of responses to McGurk stimuli was similar in both groups, suggesting that children with SLI do not suffer from an impairment of audiovisual integration. An analysis of percent of information transmitted revealed a deficit in the children with SLI, particularly for the place of articulation feature. Taken together, the data support the hypothesis of an intact peripheral processing of auditory speech information, coupled with a supra modal deficit of phonemic categorization in children with SLI. Clinical implications are discussed.

  6. On the advantage of being left-handed in volleyball: further evidence of the specificity of skilled visual perception.

    Science.gov (United States)

    Loffing, Florian; Schorer, Jörg; Hagemann, Norbert; Baker, Joseph

    2012-02-01

    High ball speeds and close distances between competitors require athletes in interactive sports to correctly anticipate an opponent's intentions in order to render appropriate reactions. Although it is considered crucial for successful performance, such skill appears impaired when athletes are confronted with a left-handed opponent, possibly because of athletes' reduced perceptual familiarity with rarely encountered left-handed actions. To test this negative perceptual frequency effect hypothesis, we invited 18 skilled and 18 novice volleyball players to predict shot directions of left- and right-handed attacks in a video-based visual anticipation task. In accordance with our predictions, and with recent reports on laterality differences in visual perception, the outcome of left-handed actions was significantly less accurately predicted than the outcome of right-handed attacks. In addition, this left-right bias was most distinct when predictions had to be based on preimpact (i.e., before hand-ball contact) kinematic cues, and skilled players were generally more affected by the opponents' handedness than were novices. The study's findings corroborate the assumption that skilled visual perception is attuned to more frequently encountered actions.

  7. Self-estimation of physical ability in stepping over an obstacle is not mediated by visual height perception: a comparison between young and older adults.

    Science.gov (United States)

    Sakurai, Ryota; Fujiwara, Yoshinori; Ishihara, Masami; Yasunaga, Masashi; Ogawa, Susumu; Suzuki, Hiroyuki; Imanaka, Kuniyasu

    2017-07-01

    Older adults tend to overestimate their step-over ability. However, it is unclear as to whether this is caused by inaccurate self-estimation of physical ability or inaccurate perception of height. We, therefore, measured both visual height perception ability and self-estimation of step-over ability among young and older adults. Forty-seven older and 16 young adults performed a height perception test (HPT) and a step-over test (SOT). Participants visually judged the height of vertical bars from distances of 7 and 1 m away in the HPT, then self-estimated and, subsequently, actually performed a step-over action in the SOT. The results showed no significant difference between young and older adults in visual height perception. In the SOT, young adults tended to underestimate their step-over ability, whereas older adults either overestimated their abilities or underestimated them to a lesser extent than did the young adults. Moreover, visual height perception was not correlated with the self-estimation of step-over ability in both young and older adults. These results suggest that the self-overestimation of step-over ability which appeared in some healthy older adults may not be caused by the nature of visual height perception, but by other factor(s), such as the likely age-related nature of self-estimation of physical ability, per se.

  8. Peripheral Vision of Youths with Low Vision: Motion Perception, Crowding, and Visual Search

    Science.gov (United States)

    Tadin, Duje; Nyquist, Jeffrey B.; Lusk, Kelly E.; Corn, Anne L.; Lappin, Joseph S.

    2012-01-01

    Purpose. Effects of low vision on peripheral visual function are poorly understood, especially in children whose visual skills are still developing. The aim of this study was to measure both central and peripheral visual functions in youths with typical and low vision. Of specific interest was the extent to which measures of foveal function predict performance of peripheral tasks. Methods. We assessed central and peripheral visual functions in youths with typical vision (n = 7, ages 10–17) and low vision (n = 24, ages 9–18). Experimental measures used both static and moving stimuli and included visual crowding, visual search, motion acuity, motion direction discrimination, and multitarget motion comparison. Results. In most tasks, visual function was impaired in youths with low vision. Substantial differences, however, were found both between participant groups and, importantly, across different tasks within participant groups. Foveal visual acuity was a modest predictor of peripheral form vision and motion sensitivity in either the central or peripheral field. Despite exhibiting normal motion discriminations in fovea, motion sensitivity of youths with low vision deteriorated in the periphery. This contrasted with typically sighted participants, who showed improved motion sensitivity with increasing eccentricity. Visual search was greatly impaired in youths with low vision. Conclusions. Our results reveal a complex pattern of visual deficits in peripheral vision and indicate a significant role of attentional mechanisms in observed impairments. These deficits were not adequately captured by measures of foveal function, arguing for the importance of independently assessing peripheral visual function. PMID:22836766

  9. Explaining academic-track boys' underachievement in language grades: Not a lack of aptitude but students' motivational beliefs and parents' perceptions?

    Science.gov (United States)

    Heyder, Anke; Kessels, Ursula; Steinmayr, Ricarda

    2017-06-01

    Boys earn lower grades in languages than girls. The expectancy-value model by Eccles et al. (, A series of books in psychology. Achievement and achievement motives. Psychological and sociological approaches, W.H. Freeman, San Francisco, CA, 76) is a comprehensive theoretical model for explaining gender differences in educational outcomes. In the past, most studies have focused on girls' disadvantage in math and science and on the role of the students' motivational beliefs. We aimed to explain boys' lower language grades by applying the expectancy-value model while taking into account students' motivational beliefs as well as their aptitude, prior achievement, and socializers' beliefs. In addition, we aimed at exploring the incremental contribution of each potential mediator. Five hundred and twenty German students (age M = 17 years; 58% female) and 374 parents (age M = 47 years). Student-reported ability self-concept (ASC) and task values, parents' perceptions of students' ability, students' prior achievement as reported by schools, and students' verbal intelligence test scores were all tested as mediators of the effect of gender on grades in German while controlling for parents' socioeconomic status. Single-mediator models and a multiple-mediator model were estimated using structural equation modelling. All variables proved to be relevant for explaining boys' underachievement in language grades. Whereas students' ASC, task values, prior achievement, and parents' perceptions mediated the gender effect, verbal intelligence was identified as a suppressor variable increasing the gender effect. Our results challenge the stereotypic belief that boys' lower grades are due to lower verbal aptitude. Rather, students' motivational beliefs and parents' perceptions seem critical factors. Implications for both future research and practice are discussed. © 2017 The British Psychological Society.

  10. Review of Visual Speech Perception by Hearing and Hearing-Impaired People: Clinical Implications

    Science.gov (United States)

    Woodhouse, Lynn; Hickson, Louise; Dodd, Barbara

    2009-01-01

    Background: Speech perception is often considered specific to the auditory modality, despite convincing evidence that speech processing is bimodal. The theoretical and clinical roles of speech-reading for speech perception, however, have received little attention in speech-language therapy. Aims: The role of speech-read information for speech…

  11. Reinforcement of perceptual inference: reward and punishment alter conscious visual perception during binoculair rivalry

    NARCIS (Netherlands)

    Wilbertz, G.; van Slooten, J.C.; Sterzer, P.

    2014-01-01

    Perception is an inferential process, which becomes immediately evident when sensory information is conflicting or ambiguous and thus allows for more than one perceptual interpretation. Thinking the idea of perception as inference through to the end results in a blurring of boundaries between

  12. simEye: computer-based simulation of visual perception under various eye defects using Zernike polynomials

    OpenAIRE

    Fink, Wolfgang; Micol, Daniel

    2006-01-01

    We describe a computer eye model that allows for aspheric surfaces and a three-dimensional computer-based ray-tracing technique to simulate optical properties of the human eye and visual perception under various eye defects. Eye surfaces, such as the cornea, eye lens, and retina, are modeled or approximated by a set of Zernike polynomials that are fitted to input data for the respective surfaces. A ray-tracing procedure propagates light rays using Snell’s law of refraction from an input objec...

  13. Emotionalization in Science Communication: The Impact of Narratives and Visual Representations on Knowledge Gain and Risk Perception

    Directory of Open Access Journals (Sweden)

    Danny Flemming

    2018-01-01

    Full Text Available The communication of scientific information plays an increasingly important role for scientists and scientific institutions. This is especially true of institutions in the field of biodiversity and conservation research, since the transfer of research results to the public is a prerequisite for decision-making, and the success of conservation measures often depends on public acceptance or active contribution. To have the desired impact, science communication in the context of human–wildlife interactions must enable recipients to (1 gain valid knowledge, (2 form an attitude toward the subject matter, and (3 develop an adequate understanding of the risks and dangers associated with human–wildlife interactions, which are usually overestimated by the general public. Using the topic of foxes in urban habitats, we investigated the role of emotionalization in science communication. In a laboratory experiment with 127 university students (91 females, we manipulated textual and visual features in an information brochure about foxes and examined their impact on people’s knowledge gain, attitude development, and modified risk perception. In particular, we compared a narrative presentation to a non-narrative list of facts and examined the use of photographs of young foxes. We found a positive development in all of the outcome variables from the pre- to the posttest (more knowledge, more positive attitude, lower risk perception. We also found an interaction effect of text type and visualization on knowledge gain that highlighted the importance of the fit between text type and visualization. In contrast to our expectations, we did not find any differential effects of specific treatments on attitude development. Finally, we found a main effect of text type on modified risk perception, indicating less reduction of risk perception with a narrative article than with a fact list. We discuss our findings with respect to the role of emotionalization in science

  14. Differences in visual perception of age and attractiveness of female facial and body skin.

    Science.gov (United States)

    Fink, B; Matts, P J; Röder, S; Johnson, R; Burquest, M

    2011-04-01

    Perception of age and health is critical in the judgement of attractiveness. The few studies conducted on the significance of apparent skin condition on human physical appearance have studied faces alone or isolated fields of images facial skin. Little is known about whether perception of the face matches that of other body parts or if body skin affects overall age and attractiveness perception when presented in combination with facial skin. We hypothesized that independent presentation of female faces, chests and arms (including hands) - cropped from a full face and upper body image - would result in significant differences in perception of age and attractiveness compared to the corresponding composite. Furthermore, we sought to investigate whether relatively young and attractive looking skin on selected, individual parts of the body affects overall perception. Digital photographs of 52 women aged 45-65 years were collected and processed to yield four derivative sets of images: One set showed the composite of all features, i.e. the face, the chest and the arms, whereas the other three were cropped carefully to show each part of the upper body described above independently. A total of 240 participants judged these faces for perceived age and attractiveness. Our results showed significant differences in perception with the chest and the arms being judged significantly younger than the face or composite image of the same women. Moreover, arms and chest images were perceived as more attractive than face and composite images. Finally, regression analysis indicated that differences between the perceived and chronological values of overall age perception could be predicted by age perception of the face and arms. These results continue to support the significance of facial age perception in assessment of a woman's age, but highlight that body skin also plays a role in overall age impression. © 2010 The Authors. ICS © 2010 Society of Cosmetic Scientists and the Soci

  15. Integration of Visual, Vestibular and Somatosensory Information for the Perception of Gravitational Vertical and Forward Self-Motion

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    Yuji Kasahara

    2011-10-01

    Full Text Available We investigated how human perceives forward self-motion from the information produced by the vestibular, somatosensory and visual systems. In the experiments, we manipulated vestibular and somatosensory information by changing the direction of the subject's body. The subject sat in a drum which was tilted about the pitch axis of the subject. We also manipulated the visual information by presenting optic flow of dots on the display in front of the subject. In Exp.1, the pitch of subject was fixed at a certain angle for each trial. In Exp.2, the pitch angle was changed temporally, and the acceleration of the optic flow was synchronized with the angle to simulate the flow produced by the forward self-motion of the acceleration. During the trials, the subject continuously responded the gravitational vertical. In the condition of fixed pitch angle (Exp.1, subjects' responses of the gravitational vertical almost corresponded to the real direction and were not affected by the visual stimulus. In the condition of changing pitch angle (Exp.2, the responses were close to the direction of their foot. These results suggest that, the temporal correspondence between vestibular, somatosensory and visual information is important for the perception of forward self-motion.

  16. [Objective assessment of disorders of visual perception following unilateral vestibular loss. Studies of the so-called Dandy symptom].

    Science.gov (United States)

    Stoll, W; Werner, F; Kauffmann, G

    1991-02-01

    Visual ability and compensatory eye movements during defined vertical oscillation were investigated in 20 patients with unilateral lesions of labyrinthine function and in 20 normal subjects. Oscillation frequencies were performed at the rate of 1 to 1.5 Hz with an amplitude of 5 cm, comparative to head locomotions of a running person. In synchronism with this, the visual function was tested with Landolt rings. Patients complaining of subjective visual disturbance during walking and running, also presented a measurable blur of vision under test conditions. In addition, eye movements were recorded and classified into three types. However, these eye movements showed no relation to gaze function. Our results suggest that the otolith-ocular reflex may participate in adjusting the vertical eye position during vertical stimulations at low frequencies. The effect of visual disturbances in patients with labyrinthine lesions is explained by the "efference-copy" initially described by von Holst. The efference-copy is responsible for the neutralisation of provoked retinal perceptions.

  17. The importance of stimulation of sensory perception by preschool-aged children with visual impairment

    OpenAIRE

    NOHAVOVÁ, Lenka

    2014-01-01

    This bachelor thesis engages in the topic "Stimulation of sense perception for sight-impaired children at preschool age". The theoretical section of the bachelor thesis is divided into four chapters. The first chapter focuses on the sight-impaired individual, the second chapter deals with the development of a preschool-aged child, the next chapter is concerned with the preschool education of sight-impaired children and the last chapter focuses on sense perception for those children. The main ...

  18. Perceptions of Schooling, Pedagogy and Notation in the Lives of Visually-Impaired Musicians

    Science.gov (United States)

    Baker, David; Green, Lucy

    2016-01-01

    This article discusses findings on schooling, pedagogy and notation in the life-experiences of amateur and professional visually-impaired musicians/music teachers, and the professional experiences of sighted music teachers who work with visually-impaired learners. The study formed part of a broader UK Arts and Humanities Research Council funded…

  19. Auditory and Visual Differences in Time Perception? An Investigation from a Developmental Perspective with Neuropsychological Tests

    Science.gov (United States)

    Zelanti, Pierre S.; Droit-Volet, Sylvie

    2012-01-01

    Adults and children (5- and 8-year-olds) performed a temporal bisection task with either auditory or visual signals and either a short (0.5-1.0s) or long (4.0-8.0s) duration range. Their working memory and attentional capacities were assessed by a series of neuropsychological tests administered in both the auditory and visual modalities. Results…

  20. Temperament and Young Children with Visual Impairments: Perceptions of Anglo and Latino Parents

    Science.gov (United States)

    Dote-Kwan, Jamie; Chen, Deborah

    2010-01-01

    This study examined the temperamental characteristics of 18 toddlers with visual impairments as reported by their Anglo and Latino (Mexican American) parents. Differences in the parents' ratings of the children's temperament were related to the children's level of visual functioning and development. No differences were related to the children's…

  1. Using auditory-visual speech to probe the basis of noise-impaired consonant-vowel perception in dyslexia and auditory neuropathy

    Science.gov (United States)

    Ramirez, Joshua; Mann, Virginia

    2005-08-01

    Both dyslexics and auditory neuropathy (AN) subjects show inferior consonant-vowel (CV) perception in noise, relative to controls. To better understand these impairments, natural acoustic speech stimuli that were masked in speech-shaped noise at various intensities were presented to dyslexic, AN, and control subjects either in isolation or accompanied by visual articulatory cues. AN subjects were expected to benefit from the pairing of visual articulatory cues and auditory CV stimuli, provided that their speech perception impairment reflects a relatively peripheral auditory disorder. Assuming that dyslexia reflects a general impairment of speech processing rather than a disorder of audition, dyslexics were not expected to similarly benefit from an introduction of visual articulatory cues. The results revealed an increased effect of noise masking on the perception of isolated acoustic stimuli by both dyslexic and AN subjects. More importantly, dyslexics showed less effective use of visual articulatory cues in identifying masked speech stimuli and lower visual baseline performance relative to AN subjects and controls. Last, a significant positive correlation was found between reading ability and the ameliorating effect of visual articulatory cues on speech perception in noise. These results suggest that some reading impairments may stem from a central deficit of speech processing.

  2. Audio-visual speech perception in infants and toddlers with Down syndrome, fragile X syndrome, and Williams syndrome.

    Science.gov (United States)

    D'Souza, Dean; D'Souza, Hana; Johnson, Mark H; Karmiloff-Smith, Annette

    2016-08-01

    Typically-developing (TD) infants can construct unified cross-modal percepts, such as a speaking face, by integrating auditory-visual (AV) information. This skill is a key building block upon which higher-level skills, such as word learning, are built. Because word learning is seriously delayed in most children with neurodevelopmental disorders, we assessed the hypothesis that this delay partly results from a deficit in integrating AV speech cues. AV speech integration has rarely been investigated in neurodevelopmental disorders, and never previously in infants. We probed for the McGurk effect, which occurs when the auditory component of one sound (/ba/) is paired with the visual component of another sound (/ga/), leading to the perception of an illusory third sound (/da/ or /tha/). We measured AV integration in 95 infants/toddlers with Down, fragile X, or Williams syndrome, whom we matched on Chronological and Mental Age to 25 TD infants. We also assessed a more basic AV perceptual ability: sensitivity to matching vs. mismatching AV speech stimuli. Infants with Williams syndrome failed to demonstrate a McGurk effect, indicating poor AV speech integration. Moreover, while the TD children discriminated between matching and mismatching AV stimuli, none of the other groups did, hinting at a basic deficit or delay in AV speech processing, which is likely to constrain subsequent language development. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Where perception meets memory: a review of repetition priming in visual search tasks.

    Science.gov (United States)

    Kristjánsson, Arni; Campana, Gianluca

    2010-01-01

    What we have recently seen and attended to strongly influences how we subsequently allocate visual attention. A clear example is how repeated presentation of an object's features or location in visual search tasks facilitates subsequent detection or identification of that item, a phenomenon known as priming. Here, we review a large body of results from priming studies that suggest that a short-term implicit memory system guides our attention to recently viewed items. The nature of this memory system and the processing level at which visual priming occurs are still debated. Priming might be due to activity modulations of low-level areas coding simple stimulus characteristics or to higher level episodic memory representations of whole objects or visual scenes. Indeed, recent evidence indicates that only minor changes to the stimuli used in priming studies may alter the processing level at which priming occurs. We also review recent behavioral, neuropsychological, and neurophysiological evidence that indicates that the priming patterns are reflected in activity modulations at multiple sites along the visual pathways. We furthermore suggest that studies of priming in visual search may potentially shed important light on the nature of cortical visual representations. Our conclusion is that priming occurs at many different levels of the perceptual hierarchy, reflecting activity modulations ranging from lower to higher levels, depending on the stimulus, task, and context-in fact, the neural loci that are involved in the analysis of the stimuli for which priming effects are seen.

  4. Visuospatial function in early Alzheimer's disease--the use of the Visual Object and Space Perception (VOSP battery.

    Directory of Open Access Journals (Sweden)

    Natália Bezerra Mota Quental

    Full Text Available Alzheimer's disease (AD is the most frequent cause of dementia. The clinical symptoms of AD begin with impairment of memory and executive function followed by the gradual involvement of other functions, such as language, semantic knowledge, abstract thinking, attention, and visuospatial abilities. Visuospatial function involves the identification of a stimulus and its location and can be impaired at the beginning of AD. The Visual Object and Space Perception (VOSP battery evaluates visuospatial function, while minimizing the interference of other cognitive functions.To evaluate visuospatial function in early AD patients using the VOSP and determine cutoff scores to differentiate between cognitively healthy individuals and AD patients.Thirty-one patients with mild AD and forty-four healthy elderly were evaluated using a neuropsychological battery and the VOSP.In the VOSP, the AD patients performed more poorly in all subtests examining object perception and in two subtests examining space perception (Number Location and Cube Analysis. The VOSP showed good accuracy and good correlation with tests measuring visuospatial function.Visuospatial function is impaired in the early stages of AD. The VOSP battery is a sensitive battery test for visuospatial deficits with minimal interference by other cognitive functions.

  5. Visuospatial function in early Alzheimer's disease--the use of the Visual Object and Space Perception (VOSP) battery.

    Science.gov (United States)

    Quental, Natália Bezerra Mota; Brucki, Sonia Maria Dozzi; Bueno, Orlando Francisco Amodeo

    2013-01-01

    Alzheimer's disease (AD) is the most frequent cause of dementia. The clinical symptoms of AD begin with impairment of memory and executive function followed by the gradual involvement of other functions, such as language, semantic knowledge, abstract thinking, attention, and visuospatial abilities. Visuospatial function involves the identification of a stimulus and its location and can be impaired at the beginning of AD. The Visual Object and Space Perception (VOSP) battery evaluates visuospatial function, while minimizing the interference of other cognitive functions. To evaluate visuospatial function in early AD patients using the VOSP and determine cutoff scores to differentiate between cognitively healthy individuals and AD patients. Thirty-one patients with mild AD and forty-four healthy elderly were evaluated using a neuropsychological battery and the VOSP. In the VOSP, the AD patients performed more poorly in all subtests examining object perception and in two subtests examining space perception (Number Location and Cube Analysis). The VOSP showed good accuracy and good correlation with tests measuring visuospatial function. Visuospatial function is impaired in the early stages of AD. The VOSP battery is a sensitive battery test for visuospatial deficits with minimal interference by other cognitive functions.

  6. Ways of incorporating photographic images in learning and assessing high school biology: A study of visual perception and visual cognition

    Science.gov (United States)

    Nixon, Brenda Chaumont

    This study evaluated the cognitive benefits and costs of incorporating biology-textbook and student-generated photographic images into the learning and assessment processes within a 10th grade biology classroom. The study implemented Wandersee's (2000) 20-Q Model of Image-Based Biology Test-Item Design (20-Q Model) to explore the use of photographic images to assess students' understanding of complex biological processes. A thorough review of the students' textbook using ScaleMaster R with PC Interface was also conducted. The photographs, diagrams, and other representations found in the textbook were measured to determine the percentage of each graphic depicted in the book and comparisons were made to the text. The theoretical framework that guided the research included Human Constructivist tenets espoused by Mintzes, Wandersee and Novak (2000). Physiological and cognitive factors of images and image-based learning as described by Robin (1992), Solso (1997) and Wandersee (2000) were examined. Qualitative case study design presented by Yin (1994), Denzin and Lincoln (1994) was applied and data were collected through interviews, observations, student activities, student and school artifacts and Scale Master IIRTM measurements. The results of the study indicate that although 24% of the high school biology textbook is devoted to photographic images which contribute significantly to textbook cost, the teacher and students paid little attention to photographic images other than as aesthetic elements for creating biological ambiance, wasting valuable opportunities for learning. The analysis of the photographs corroborated findings published by the Association American Association for the Advancement of Science that indicated "While most of the books are lavishly illustrated, these representations are rarely helpful, because they are too abstract, needlessly complicated, or inadequately explained" (Roseman, 2000, p. 2). The findings also indicate that applying the 20-Q

  7. Assessing The Impact of Personality Characteristics on Students’ Visual Perception for Landscapes

    Directory of Open Access Journals (Sweden)

    Sima Alizadeh

    2017-09-01

    Full Text Available As landscape plays a crucial role in people’s lives, it is of great importance that landscape is designed based on people’s interest. Therefore, identification of the landscapes that people prefer and the factors that influence their perception are imperative. This research attempts to investigate the contribution of personality characteristics towards students’ landscape perception in Isfahan, Iran. In this aspect, students’ characteristics of extroversion/ introversion, intelligence, and creativity were measured by using Cattell’s 16PF Questionnaire. Also, the respondents were asked to express their feeling of satisfaction and happiness towards six common landscape types of Iran, by rating 30 images of mountainous, urban, forest, desert, water, and farmland landscapes. The results of Pearson Correlation Coefficient indicated that extroverted students have a greater feeling for both mountainous and urban landscapes than introverts. Also, less creative students preferred mountainous, urban, and farmland landscapes. Moreover, perception for farmland landscape was negatively correlated with intelligence among students.

  8. Filling-in and suppression of visual perception from context: a Bayesian account of perceptual biases by contextual influences.

    Directory of Open Access Journals (Sweden)

    Li Zhaoping

    2008-02-01

    Full Text Available Visual object recognition and sensitivity to image features are largely influenced by contextual inputs. We study influences by contextual bars on the bias to perceive or infer the presence of a target bar, rather than on the sensitivity to image features. Human observers judged from a briefly presented stimulus whether a target bar of a known orientation and shape is present at the center of a display, given a weak or missing input contrast at the target location with or without a context of other bars. Observers are more likely to perceive a target when the context has a weaker rather than stronger contrast. When the context can perceptually group well with the would-be target, weak contrast contextual bars bias the observers to perceive a target relative to the condition without contexts, as if to fill in the target. Meanwhile, high-contrast contextual bars, regardless of whether they group well with the target, bias the observers to perceive no target. A Bayesian model of visual inference is shown to account for the data well, illustrating that the context influences the perception in two ways: (1 biasing observers' prior belief that a target should be present according to visual grouping principles, and (2 biasing observers' internal model of the likely input contrasts caused by a target bar. According to this model, our data suggest that the context does not influence the perceived target contrast despite its influence on the bias to perceive the target's presence, thereby suggesting that cortical areas beyond the primary visual cortex are responsible for the visual inferences.

  9. The use of auditory and visual context in speech perception by listeners with normal hearing and listeners with cochlear implants

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    Matthew eWinn

    2013-11-01

    Full Text Available There is a wide range of acoustic and visual variability across different talkers and different speaking contexts. Listeners with normal hearing accommodate that variability in ways that facilitate efficient perception, but it is not known whether listeners with cochlear implants can do the same. In this study, listeners with normal hearing (NH and listeners with cochlear implants (CIs were tested for accommodation to auditory and visual phonetic contexts created by gender-driven speech differences as well as vowel coarticulation and lip rounding in both consonants and vowels. Accommodation was measured as the shifting of perceptual boundaries between /s/ and /ʃ/ sounds in various contexts, as modeled by mixed-effects logistic regression. Owing to the spectral contrasts thought to underlie these context effects, CI listeners were predicted to perform poorly, but showed considerable success. Listeners with cochlear implants not only showed sensitivity to auditory cues to gender, they were also able to use visual cues to gender (i.e. faces as a supplement or proxy for information in the acoustic domain, in a pattern that was not observed for listeners with normal hearing. Spectrally-degraded stimuli heard by listeners with normal hearing generally did not elicit strong context effects, underscoring the limitations of noise vocoders and/or the importance of experience with electric hearing. Visual cues for consonant lip rounding and vowel lip rounding were perceived in a manner consistent with coarticulation and were generally used more heavily by listeners with CIs. Results suggest that listeners with cochlear implants are able to accommodate various sources of acoustic variability either by attending to appropriate acoustic cues or by inferring them via the visual signal.

  10. Influence of combined visual and vestibular cues on human perception and control of horizontal rotation

    Science.gov (United States)

    Zacharias, G. L.; Young, L. R.

    1981-01-01

    Measurements are made of manual control performance in the closed-loop task of nulling perceived self-rotation velocity about an earth-vertical axis. Self-velocity estimation is modeled as a function of the simultaneous presentation of vestibular and peripheral visual field motion cues. Based on measured low-frequency operator behavior in three visual field environments, a parallel channel linear model is proposed which has separate visual and vestibular pathways summing in a complementary manner. A dual-input describing function analysis supports the complementary model; vestibular cues dominate sensation at higher frequencies. The describing function model is extended by the proposal of a nonlinear cue conflict model, in which cue weighting depends on the level of agreement between visual and vestibular cues.

  11. Internal state of monkey primary visual cortex (V1) predicts figure ground perception

    NARCIS (Netherlands)

    Super, H.; Spekreijse, H.; Lamme, V.A.F.

    2003-01-01

    When stimulus information enters the visual cortex, it is rapidly processed for identification. However, sometimes the processing of thestimulus is inadequate and the subject fails to notice the stimulus. Human psychophysical studies show that this occurs during states ofinattention or

  12. Multisensory object perception in infancy: 4-month-olds perceive a mistuned harmonic as a separate auditory and visual object.

    Science.gov (United States)

    Smith, Nicholas A; Folland, Nicole A; Martinez, Diana M; Trainor, Laurel J

    2017-07-01

    Infants learn to use auditory and visual information to organize the sensory world into identifiable objects with particular locations. Here we use a behavioural method to examine infants' use of harmonicity cues to auditory object perception in a multisensory context. Sounds emitted by different objects sum in the air and the auditory system must figure out which parts of the complex waveform belong to different sources (auditory objects). One important cue to this source separation is that complex tones with pitch typically contain a fundamental frequency and harmonics at integer multiples of the fundamental. Consequently, adults hear a mistuned harmonic in a complex sound as a distinct auditory object (Alain, Theunissen, Chevalier, Batty, & Taylor, 2003). Previous work by our group demonstrated that 4-month-old infants are also sensitive to this cue. They behaviourally discriminate a complex tone with a mistuned harmonic from the same complex with in-tune harmonics, and show an object-related event-related potential (ERP) electrophysiological (EEG) response to the stimulus with mistuned harmonics. In the present study we use an audiovisual procedure to investigate whether infants perceive a complex tone with an 8% mistuned harmonic as emanating from two objects, rather than merely detecting the mistuned cue. We paired in-tune and mistuned complex tones with visual displays that contained either one or two bouncing balls. Four-month-old infants showed surprise at the incongruous pairings, looking longer at the display of two balls when paired with the in-tune complex and at the display of one ball when paired with the mistuned harmonic complex. We conclude that infants use harmonicity as a cue for source separation when integrating auditory and visual information in object perception. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Is conscious perception gradual or dichotomous? A comparison of report methodologies during a visual task

    DEFF Research Database (Denmark)

    Overgaard, M; Rote, J; Mouridsen, K

    2006-01-01

    In a recent article, [Sergent, C. & Dehaene, S. (2004). Is consciousness a gradual phenomenon? Evidence for an all-or-none bifurcation during the attentional blink, Psychological Science, 15(11), 720-729] claim to give experimental support to the thesis that there is a clear transition between...... study described in this article, we find support for this opposite notion that we should have a parsimonious account of conscious perception. Our reported finding relates to the hypothesis that there is more than one perceptual threshold [Merikle, P.M., Smilek, D. & Eastwood, J.D. (2001). Perception...

  14. Seeing touch in the somatosensory cortex: a TMS study of the visual perception of touch.

    Science.gov (United States)

    Bolognini, Nadia; Rossetti, Angela; Maravita, Angelo; Miniussi, Carlo

    2011-12-01

    Recent studies suggest the existence of a visuo-tactile mirror system, comprising the primary (SI) and secondary (SII) somatosensory cortices, which matches observed touch with felt touch. Here, repetitive transcranial magnetic stimulation (rTMS) was used to determine whether SI or SII play a functional role in the visual processing of tactile events. Healthy participants performed a visual discrimination task with tactile stimuli (a finger touching a hand) and a control task (a finger moving without touching). During both tasks, rTMS was applied over either SI or SII, and to the occipital cortex. rTMS over SI selectively reduced subject performance for interpreting whether a contralateral visual tactile stimulus contains a tactile event, whereas SII stimulation impaired visual processing regardless of the tactile component. These findings provide evidence for a multimodal sensory-motor system with mirror properties, where somatic and visual properties of action converge. SI, a cortical area traditionally viewed as modality-specific, is selectively implicated in the visual processing of touch. These results are in line with the existence of a sensory mirror system mediating the embodied simulation concept. Copyright © 2010 Wiley Periodicals, Inc.

  15. Assessment as a Barrier in Developing Design Expertise: Interior Design Student Perceptions of Meanings and Sources of Grades

    Science.gov (United States)

    Smith, Kennon M.

    2013-01-01

    This article reports on a portion of a larger qualitative study focused on a group of interior design students' perceptions of their educational experiences. Twelve interior design students enrolled in their final studio course participated in interviews intended to elicit their perceptions of key barriers encountered during their undergraduate…

  16. Brand visualization: Effects of "product shape- typeface design" congruence on brand perceptions and price expectations

    NARCIS (Netherlands)

    van Rompay, Thomas Johannes Lucas; Pruyn, Adriaan T.H.

    2008-01-01

    This research addresses effects of congruence of symbolic meanings connoted through product shape and typeface design on brand perceptions and price expectations. Based on processing fluency accounts, it is predicted that shape-typeface congruence, as opposed to shape-typeface incongruence,

  17. When MOOD rhymes with ROAD: Dynamics of phonological coding in bilingual visual word perception

    NARCIS (Netherlands)

    Leerdam, M. van; Bosman, A.M.T.; Groot, A.M.B. de

    2009-01-01

    Three experiments investigated whether perception of a spelling-to-sound inconsistent word such as MOOD involves coding of inappropriate phonology caused by knowledge of enemy neighbors (e.g., BLOOD) in non-native speakers. In a new bimodal matching task, Dutch-English bilinguals judged the

  18. A Comparison of Community College Full-Time and Adjunct Faculties' Perceptions of Factors Associated with Grade Inflation

    Science.gov (United States)

    Schutz, Kelly R.; Drake, Brent M.; Lessner, Janet; Hughes, Gail F.

    2015-01-01

    Grades historically have indicated student performance in college. Previous studies in the higher education literature, primarily conducted at four-year teaching institutions, have suggested reasons for grade inflation but have provided little supporting empirical data. This quantitative, non-experimental, comparative study used survey research to…

  19. Negative body image associated with changes in the visual body appearance increases pain perception.

    Science.gov (United States)

    Osumi, Michihiro; Imai, Ryota; Ueta, Kozo; Nobusako, Satoshi; Morioka, Shu

    2014-01-01

    Changing the visual body appearance by use of as virtual reality system, funny mirror, or binocular glasses has been reported to be helpful in rehabilitation of pain. However, there are interindividual differences in the analgesic effect of changing the visual body image. We hypothesized that a negative body image associated with changing the visual body appearance causes interindividual differences in the analgesic effect although the relationship between the visual body appearance and analgesic effect has not been clarified. We investigated whether a negative body image associated with changes in the visual body appearance increased pain. Twenty-five healthy individuals participated in this study. To evoke a negative body image, we applied the method of rubber hand illusion. We created an "injured rubber hand" to evoke unpleasantness associated with pain, a "hairy rubber hand" to evoke unpleasantness associated with embarrassment, and a "twisted rubber hand" to evoke unpleasantness associated with deviation from the concept of normality. We also created a "normal rubber hand" as a control. The pain threshold was measured while the participant observed the rubber hand using a device that measured pain caused by thermal stimuli. Body ownership experiences were elicited by observation of the injured rubber hand and hairy rubber hand as well as the normal rubber hand. Participants felt more unpleasantness by observing the injured rubber hand and hairy rubber hand than the normal rubber hand and twisted rubber hand (pappearance associated with pain can increase pain sensitivity.

  20. Neural Correlates of Body and Face Perception Following Bilateral Destruction of the Primary Visual Cortices

    Directory of Open Access Journals (Sweden)

    Jan eVan den Stock

    2014-02-01

    Full Text Available Non-conscious visual processing of different object categories was investigated in a rare patient with bilateral destruction of the visual cortex (V1 and clinical blindness over the entire visual field. Images of biological and non-biological object categories were presented consisting of human bodies, faces, butterflies, cars, and scrambles. Behaviorally, only the body shape induced higher perceptual sensitivity, as revealed by signal detection analysis. Passive exposure to bodies and faces activated amygdala and superior temporal sulcus. In addition, bodies also activated the extrastriate body area, insula, orbitofrontal cortex (OFC and cerebellum. The results show that following bilateral damage to the primary visual cortex and ensuing complete cortical blindness, the human visual system is able to process categorical properties of human body shapes. This residual vision may be based on V1-independent input to body-selective areas along the ventral stream, in concert with areas involved in the representation of bodily states, like insula, OFC and cerebellum.