Sample records for abnormal visual experience

  1. Sparse coding can predict primary visual cortex receptive field changes induced by abnormal visual input.

    PubMed

    Hunt, Jonathan J; Dayan, Peter; Goodhill, Geoffrey J

    2013-01-01

    Receptive fields acquired through unsupervised learning of sparse representations of natural scenes have similar properties to primary visual cortex (V1) simple cell receptive fields. However, what drives in vivo development of receptive fields remains controversial. The strongest evidence for the importance of sensory experience in visual development comes from receptive field changes in animals reared with abnormal visual input. However, most sparse coding accounts have considered only normal visual input and the development of monocular receptive fields. Here, we applied three sparse coding models to binocular receptive field development across six abnormal rearing conditions. In every condition, the changes in receptive field properties previously observed experimentally were matched to a similar and highly faithful degree by all the models, suggesting that early sensory development can indeed be understood in terms of an impetus towards sparsity. As previously predicted in the literature, we found that asymmetries in inter-ocular correlation across orientations lead to orientation-specific binocular receptive fields. Finally we used our models to design a novel stimulus that, if present during rearing, is predicted by the sparsity principle to lead robustly to radically abnormal receptive fields.

  2. Sparse Coding Can Predict Primary Visual Cortex Receptive Field Changes Induced by Abnormal Visual Input

    PubMed Central

    Hunt, Jonathan J.; Dayan, Peter; Goodhill, Geoffrey J.

    2013-01-01

    Receptive fields acquired through unsupervised learning of sparse representations of natural scenes have similar properties to primary visual cortex (V1) simple cell receptive fields. However, what drives in vivo development of receptive fields remains controversial. The strongest evidence for the importance of sensory experience in visual development comes from receptive field changes in animals reared with abnormal visual input. However, most sparse coding accounts have considered only normal visual input and the development of monocular receptive fields. Here, we applied three sparse coding models to binocular receptive field development across six abnormal rearing conditions. In every condition, the changes in receptive field properties previously observed experimentally were matched to a similar and highly faithful degree by all the models, suggesting that early sensory development can indeed be understood in terms of an impetus towards sparsity. As previously predicted in the literature, we found that asymmetries in inter-ocular correlation across orientations lead to orientation-specific binocular receptive fields. Finally we used our models to design a novel stimulus that, if present during rearing, is predicted by the sparsity principle to lead robustly to radically abnormal receptive fields. PMID:23675290

  3. Multifocal visual evoked potential and automated perimetry abnormalities in strabismic amblyopes.

    PubMed

    Greenstein, Vivienne C; Eggers, Howard M; Hood, Donald C

    2008-02-01

    To compare visual field abnormalities obtained with standard automated perimetry (SAP) to those obtained with the multifocal visual evoked potential (mfVEP) technique in strabismic amblyopes. Humphrey 24-2 visual fields (HVF) and mfVEPs were obtained from each eye of 12 strabismic amblyopes. For the mfVEP, amplitudes and latencies were analyzed and probability plots were derived. Multifocal VEP and HVF hemifields were abnormal if they had clusters of two or more contiguous points at p < 0.01, or three or more contiguous points at p < 0.05 with at least one at p < 0.01. An eye was abnormal if it had an abnormal hemifield. On SAP, amblyopic eyes had significantly higher foveal thresholds (p = 0.003) and lower mean deviation values (p = 0.005) than fellow eyes. For the mfVEP, 11 amblyopic and 6 fellow eyes were abnormal. Of the 11 amblyopic eyes, 6 were abnormal on SAP. The deficits extended from the center to mid periphery. Monocular mfVEP latencies were significantly decreased for amblyopic eyes compared with control eyes (p < 0.0002). Both techniques revealed deficits in visual function across the visual field in strabismic amblyopes, but the mfVEP revealed deficits in fellow eyes and in more amblyopic eyes. In addition, mfVEP response latencies for amblyopic eyes were shorter than normal.

  4. Abnormalities in the Visual Processing of Viewing Complex Visual Stimuli Amongst Individuals With Body Image Concern.

    PubMed

    Duncum, A J F; Atkins, K J; Beilharz, F L; Mundy, M E

    2016-01-01

    Individuals with body dysmorphic disorder (BDD) and clinically concerning body-image concern (BIC) appear to possess abnormalities in the way they perceive visual information in the form of a bias towards local visual processing. As inversion interrupts normal global processing, forcing individuals to process locally, an upright-inverted stimulus discrimination task was used to investigate this phenomenon. We examined whether individuals with nonclinical, yet high levels of BIC would show signs of this bias, in the form of reduced inversion effects (i.e., increased local processing). Furthermore, we assessed whether this bias appeared for general visual stimuli or specifically for appearance-related stimuli, such as faces and bodies. Participants with high-BIC (n = 25) and low-BIC (n = 30) performed a stimulus discrimination task with upright and inverted faces, scenes, objects, and bodies. Unexpectedly, the high-BIC group showed an increased inversion effect compared to the low-BIC group, indicating perceptual abnormalities may not be present as local processing biases, as originally thought. There was no significant difference in performance across stimulus types, signifying that any visual processing abnormalities may be general rather than appearance-based. This has important implications for whether visual processing abnormalities are predisposing factors for BDD or develop throughout the disorder.

  5. Abnormal visual scan paths: a psychophysiological marker of delusions in schizophrenia.

    PubMed

    Phillips, M L; David, A S

    1998-02-09

    The role of the visual scan path as a psychophysiological marker of visual attention has been highlighted previously (Phillips and David, 1994). We investigated information processing in schizophrenic patients with severe delusions and again when the delusions were subsiding using visual scan path measurements. We aimed to demonstrate a specific deficit in processing human faces in deluded subjects by relating this to abnormal viewing strategies. Scan paths were measured in six deluded and five non-deluded schizophrenics (matched for medication and negative symptoms), and nine age-matched normal controls. Deluded subjects had abnormal scan paths in a recognition task, fixating non-feature areas significantly more than controls, but were equally accurate. Re-testing after improvement in delusional conviction revealed fewer group differences. The results suggest state-dependent abnormal information processing in schizophrenics when deluded, with reliance on less-salient visual information for decision-making.

  6. Visual scan paths are abnormal in deluded schizophrenics.

    PubMed

    Phillips, M L; David, A S

    1997-01-01

    One explanation for delusion formation is that they result from distorted appreciation of complex stimuli. The study investigated delusions in schizophrenia using a physiological marker of visual attention and information processing, the visual scan path-a map tracing the direction and duration of gaze when an individual views a stimulus. The aim was to demonstrate the presence of a specific deficit in processing meaningful stimuli (e.g. human faces) in deluded schizophrenics (DS) by relating this to abnormal viewing strategies. Visual scan paths were measured in acutely-deluded (n = 7) and non-deluded (n = 7) schizophrenics matched for medication, illness duration and negative symptoms, plus 10 age-matched normal controls. DS employed abnormal strategies for viewing single faces and face pairs in a recognition task, staring at fewer points and fixating non-feature areas to a significantly greater extent than both control groups (P < 0.05). The results indicate that DS direct their attention to less salient visual information when viewing faces. Future paradigms employing more complex stimuli and testing DS when less-deluded will allow further clarification of the relationship between viewing strategies and delusions.

  7. Childhood visual impairment: normal and abnormal visual function in the context of developmental disability.

    PubMed

    Nyong'o, Omondi L; Del Monte, Monte A

    2008-12-01

    Abnormal or failed development of vision in children may give rise to varying degrees of visual impairment and disability. Disease and organ-specific mechanisms by which visual impairments arise are presented. The presentation of these mechanisms, along with an explanation of established pathologic processes and correlative up-to-date clinical and social research in the field of pediatrics, ophthalmology, and rehabilitation medicine are discussed. The goal of this article is to enhance the practitioner's recognition and care for children with developmental disability associated with visual impairment.

  8. Isolated cortical visual loss with subtle brain MRI abnormalities in a case of hypoxic-ischemic encephalopathy.

    PubMed

    Margolin, Edward; Gujar, Sachin K; Trobe, Jonathan D

    2007-12-01

    A 16-year-old boy who was briefly asystolic and hypotensive after a motor vehicle accident complained of abnormal vision after recovering consciousness. Visual acuity was normal, but visual fields were severely constricted without clear hemianopic features. The ophthalmic examination was otherwise normal. Brain MRI performed 11 days after the accident showed no pertinent abnormalities. At 6 months after the event, brain MRI demonstrated brain volume loss in the primary visual cortex and no other abnormalities. One year later, visual fields remained severely constricted; neurologic examination, including formal neuropsychometric testing, was normal. This case emphasizes the fact that hypoxic-ischemic encephalopathy (HIE) may cause enduring damage limited to primary visual cortex and that the MRI abnormalities may be subtle. These phenomena should be recognized in the management of patients with HIE.

  9. Anorexia nervosa and body dysmorphic disorder are associated with abnormalities in processing visual information.

    PubMed

    Li, W; Lai, T M; Bohon, C; Loo, S K; McCurdy, D; Strober, M; Bookheimer, S; Feusner, J

    2015-07-01

    Anorexia nervosa (AN) and body dysmorphic disorder (BDD) are characterized by distorted body image and are frequently co-morbid with each other, although their relationship remains little studied. While there is evidence of abnormalities in visual and visuospatial processing in both disorders, no study has directly compared the two. We used two complementary modalities--event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI)--to test for abnormal activity associated with early visual signaling. We acquired fMRI and ERP data in separate sessions from 15 unmedicated individuals in each of three groups (weight-restored AN, BDD, and healthy controls) while they viewed images of faces and houses of different spatial frequencies. We used joint independent component analyses to compare activity in visual systems. AN and BDD groups demonstrated similar hypoactivity in early secondary visual processing regions and the dorsal visual stream when viewing low spatial frequency faces, linked to the N170 component, as well as in early secondary visual processing regions when viewing low spatial frequency houses, linked to the P100 component. Additionally, the BDD group exhibited hyperactivity in fusiform cortex when viewing high spatial frequency houses, linked to the N170 component. Greater activity in this component was associated with lower attractiveness ratings of faces. Results provide preliminary evidence of similar abnormal spatiotemporal activation in AN and BDD for configural/holistic information for appearance- and non-appearance-related stimuli. This suggests a common phenotype of abnormal early visual system functioning, which may contribute to perceptual distortions.

  10. Transdiagnostic psychiatric symptoms related to visual evoked potential abnormalities.

    PubMed

    Bedwell, Jeffrey S; Butler, Pamela D; Chan, Chi C; Trachik, Benjamin J

    2015-12-15

    Visual processing abnormalities have been reported across a range of psychotic and mood disorders, but are typically examined within a particular disorder. The current study used a novel transdiagnostic approach to examine diagnostic classes, clinician-rated current symptoms, and self-reported personality traits in relation to visual processing abnormalities. We examined transient visual-evoked potentials (VEPs) from 48 adults (56% female), representing a wide range of psychotic and mood disorders, as well as individuals with no history of psychiatric disorder. Stimuli were low contrast check arrays presented on green and red backgrounds. Pairwise comparisons between individuals with schizophrenia-spectrum disorders (SSD), chronic mood disorders (CMD), and nonpsychiatric controls (NC) revealed no overall differences for either P1 or N1 amplitude. However, there was a significant interaction with the color background in which the NC group showed a significant increase in P1 amplitude to the red, vs. green, background, while the SSD group showed no change. This was related to an increase in social anhedonia and general negative symptoms. Stepwise regressions across the entire sample revealed that individuals with greater apathy and/or eccentric behavior had a reduced P1 amplitude. These relationships provide clues for uncovering the underlying causal pathology for these transdiagnostic symptoms. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Is exposure to cocaine or cigarette smoke during pregnancy associated with infant visual abnormalities?

    PubMed

    Hajnal, Beatrice Latal; Ferriero, Donna M; Partridge, J Colin; Dempsey, Delia A; Good, William V

    2004-08-01

    The aim of this study was to assess the association between cocaine or cigarette smoke exposure in utero and visual outcome. A total of 153 healthy infants (89 males, 64 females; gestational age range 34 to 42 weeks) were prospectively enrolled in a masked, race-matched study. Quantitative analyses of urine and meconium were used to document exposure to cigarette smoke and cocaine. Infants with exposure to other illicit drugs, excepting marijuana, were excluded. At 6 weeks of age, grating acuity and visual system abnormalities (VSA; eyelid oedema, gaze abnormalities, and visual inattention) of 96 infants from the original study sample were assessed with the Teller acuity card procedure and a detailed neurological examination. Neither cocaine nor cigarette smoke exposure was associated with acuity or VSA. However, VSAs were associated with abnormal neurological examination, independent of drug exposure and other risk factors (odds ratio 7.9; 95% confidence interval 2.0 to 31.5;p=0.004). This unexpected finding could prove a helpful clinical marker for the infant at risk for neurological abnormalities.

  12. Basic abnormalities in visual processing affect face processing at an early age in autism spectrum disorder.

    PubMed

    Vlamings, Petra Hendrika Johanna Maria; Jonkman, Lisa Marthe; van Daalen, Emma; van der Gaag, Rutger Jan; Kemner, Chantal

    2010-12-15

    A detailed visual processing style has been noted in autism spectrum disorder (ASD); this contributes to problems in face processing and has been directly related to abnormal processing of spatial frequencies (SFs). Little is known about the early development of face processing in ASD and the relation with abnormal SF processing. We investigated whether young ASD children show abnormalities in low spatial frequency (LSF, global) and high spatial frequency (HSF, detailed) processing and explored whether these are crucially involved in the early development of face processing. Three- to 4-year-old children with ASD (n = 22) were compared with developmentally delayed children without ASD (n = 17). Spatial frequency processing was studied by recording visual evoked potentials from visual brain areas while children passively viewed gratings (HSF/LSF). In addition, children watched face stimuli with different expressions, filtered to include only HSF or LSF. Enhanced activity in visual brain areas was found in response to HSF versus LSF information in children with ASD, in contrast to control subjects. Furthermore, facial-expression processing was also primarily driven by detail in ASD. Enhanced visual processing of detailed (HSF) information is present early in ASD and occurs for neutral (gratings), as well as for socially relevant stimuli (facial expressions). These data indicate that there is a general abnormality in visual SF processing in early ASD and are in agreement with suggestions that a fast LSF subcortical face processing route might be affected in ASD. This could suggest that abnormal visual processing is causative in the development of social problems in ASD. Copyright © 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  13. Brain Growth Rate Abnormalities Visualized in Adolescents with Autism

    PubMed Central

    Hua, Xue; Thompson, Paul M.; Leow, Alex D.; Madsen, Sarah K.; Caplan, Rochelle; Alger, Jeffry R.; O’Neill, Joseph; Joshi, Kishori; Smalley, Susan L.; Toga, Arthur W.; Levitt, Jennifer G.

    2014-01-01

    Autism spectrum disorder (ASD) is a heterogeneous disorder of brain development with wide-ranging cognitive deficits. Typically diagnosed before age 3, ASD is behaviorally defined but patients are thought to have protracted alterations in brain maturation. With longitudinal magnetic resonance imaging (MRI), we mapped an anomalous developmental trajectory of the brains of autistic compared to those of typically developing children and adolescents. Using tensor-based morphometry (TBM), we created 3D maps visualizing regional tissue growth rates based on longitudinal brain MRI scans of 13 autistic and 7 typically developing boys (mean age/inter-scan interval: autism 12.0 ± 2.3 years/2.9 ± 0.9 years; control 12.3 ± 2.4/2.8 ± 0.8). The typically developing boys demonstrated strong whole-brain white matter growth during this period, but the autistic boys showed abnormally slowed white matter development (p = 0.03, corrected), especially in the parietal (p = 0.008), temporal (p = 0.03) and occipital lobes (p =0.02). We also visualized abnormal overgrowth in autism in some gray matter structures, such as the putamen and anterior cingulate cortex. Our findings reveal aberrant growth rates in brain regions implicated in social impairment, communication deficits and repetitive behaviors in autism, suggesting that growth rate abnormalities persist into adolescence. TBM revealed persisting growth rate anomalies long after diagnosis, which has implications for evaluation of therapeutic effects. PMID:22021093

  14. Brain growth rate abnormalities visualized in adolescents with autism.

    PubMed

    Hua, Xue; Thompson, Paul M; Leow, Alex D; Madsen, Sarah K; Caplan, Rochelle; Alger, Jeffry R; O'Neill, Joseph; Joshi, Kishori; Smalley, Susan L; Toga, Arthur W; Levitt, Jennifer G

    2013-02-01

    Autism spectrum disorder is a heterogeneous disorder of brain development with wide ranging cognitive deficits. Typically diagnosed before age 3, autism spectrum disorder is behaviorally defined but patients are thought to have protracted alterations in brain maturation. With longitudinal magnetic resonance imaging (MRI), we mapped an anomalous developmental trajectory of the brains of autistic compared with those of typically developing children and adolescents. Using tensor-based morphometry, we created 3D maps visualizing regional tissue growth rates based on longitudinal brain MRI scans of 13 autistic and seven typically developing boys (mean age/interscan interval: autism 12.0 ± 2.3 years/2.9 ± 0.9 years; control 12.3 ± 2.4/2.8 ± 0.8). The typically developing boys demonstrated strong whole brain white matter growth during this period, but the autistic boys showed abnormally slowed white matter development (P = 0.03, corrected), especially in the parietal (P = 0.008), temporal (P = 0.03), and occipital lobes (P = 0.02). We also visualized abnormal overgrowth in autism in gray matter structures such as the putamen and anterior cingulate cortex. Our findings reveal aberrant growth rates in brain regions implicated in social impairment, communication deficits and repetitive behaviors in autism, suggesting that growth rate abnormalities persist into adolescence. Tensor-based morphometry revealed persisting growth rate anomalies long after diagnosis, which has implications for evaluation of therapeutic effects. Copyright © 2011 Wiley Periodicals, Inc.

  15. Abnormalities of Object Visual Processing in Body Dysmorphic Disorder

    PubMed Central

    Feusner, Jamie D.; Hembacher, Emily; Moller, Hayley; Moody, Teena D.

    2013-01-01

    Background Individuals with body dysmorphic disorder may have perceptual distortions for their appearance. Previous studies suggest imbalances in detailed relative to configural/holistic visual processing when viewing faces. No study has investigated the neural correlates of processing non-symptom-related stimuli. The objective of this study was to determine whether individuals with body dysmorphic disorder have abnormal patterns of brain activation when viewing non-face/non-body object stimuli. Methods Fourteen medication-free participants with DSM-IV body dysmorphic disorder and 14 healthy controls participated. We performed functional magnetic resonance imaging while participants matched photographs of houses that were unaltered, contained only high spatial frequency (high detail) information, or only low spatial frequency (low detail) information. The primary outcome was group differences in blood oxygen level-dependent signal changes. Results The body dysmorphic disorder group showed lesser activity in the parahippocampal gyrus, lingual gyrus, and precuneus for low spatial frequency images. There were greater activations in medial prefrontal regions for high spatial frequency images, although no significant differences when compared to a low-level baseline. Greater symptom severity was associated with lesser activity in dorsal occipital cortex and ventrolateral prefrontal cortex for normal and high spatial frequency images. Conclusions Individuals with body dysmorphic disorder have abnormal brain activation patterns when viewing objects. Hypoactivity in visual association areas for configural and holistic (low detail) elements and abnormal allocation of prefrontal systems for details is consistent with a model of imbalances in global vs. local processing. This may occur not only for appearance but also for general stimuli unrelated to their symptoms. PMID:21557897

  16. Visual Sensor Based Abnormal Event Detection with Moving Shadow Removal in Home Healthcare Applications

    PubMed Central

    Lee, Young-Sook; Chung, Wan-Young

    2012-01-01

    Vision-based abnormal event detection for home healthcare systems can be greatly improved using visual sensor-based techniques able to detect, track and recognize objects in the scene. However, in moving object detection and tracking processes, moving cast shadows can be misclassified as part of objects or moving objects. Shadow removal is an essential step for developing video surveillance systems. The goal of the primary is to design novel computer vision techniques that can extract objects more accurately and discriminate between abnormal and normal activities. To improve the accuracy of object detection and tracking, our proposed shadow removal algorithm is employed. Abnormal event detection based on visual sensor by using shape features variation and 3-D trajectory is presented to overcome the low fall detection rate. The experimental results showed that the success rate of detecting abnormal events was 97% with a false positive rate of 2%. Our proposed algorithm can allow distinguishing diverse fall activities such as forward falls, backward falls, and falling asides from normal activities. PMID:22368486

  17. Effect of Developmental Binocular Vision Abnormalities on Visual Vertigo Symptoms and Treatment Outcome.

    PubMed

    Pavlou, Marousa; Acheson, James; Nicolaou, Despina; Fraser, Clare L; Bronstein, Adolfo M; Davies, Rosalyn A

    2015-10-01

    Customized vestibular rehabilitation incorporating optokinetic (OK) stimulation improves visual vertigo (VV) symptoms; however, the degree of improvement varies among individuals. Binocular vision abnormalities (misalignment of ocular axis, ie, strabismus) may be a potential risk factor. This study aimed to investigate the influence of binocular vision abnormalities on VV symptoms and treatment outcome. Sixty subjects with refractory peripheral vestibular symptoms underwent an orthoptic assessment after being recruited for participation in an 8-week customized program incorporating OK training via a full-field visual environment rotator or video display, supervised or unsupervised. Treatment response was assessed at baseline and at 8 weeks with dynamic posturography, Functional Gait Assessment (FGA), and questionnaires for symptoms, symptom triggers, and psychological state. As no significant effect of OK training type was noted for any variables, data were combined and new groups identified on the basis of the absence or presence of a binocular vision abnormality. A total of 34 among 60 subjects consented to the orthoptic assessment, of whom 8 of the 34 had binocular vision abnormalities and 30 of the 34 subjects completed both the binocular function assessment and vestibular rehabilitation program. No significant between-group differences were noted at baseline. The only significant between-group difference was observed for pre-/post-VV symptom change (P = 0.01), with significant improvements noted only for the group without binocular vision abnormalities (P < 0.0005). Common vestibular symptoms, posturography, and the FGA improved significantly for both groups (P < 0.05). Binocular vision abnormalities may affect VV symptom improvement. These findings may have important implications for the management of subjects with refractory vestibular symptoms.Video Abstract available for insights from the authors regarding clinical implication of the study findings (see

  18. Visual Field Abnormalities among Adolescent Boys with Hearing Impairments

    PubMed Central

    KHORRAMI-NEJAD, Masoud; HERAVIAN, Javad; SEDAGHAT, Mohamad-Reza; MOMENI-MOGHADAM, Hamed; SOBHANI-RAD, Davood; ASKARIZADEH, Farshad

    2016-01-01

    The aim of this study was to compare the visual field (VF) categorizations (based on the severity of VF defects) between adolescent boys with hearing impairments and those with normal hearing. This cross-sectional study involved the evaluation of the VF of 64 adolescent boys with hearing impairments and 68 age-matched boys with normal hearing at high schools in Tehran, Iran, in 2013. All subjects had an intelligence quotient (IQ) > 70. The hearing impairments were classified based on severity and time of onset. Participants underwent a complete eye examination, and the VFs were investigated using automated perimetry with a Humphrey Visual Field Analyzer. This device was used to determine their foveal threshold (FT), mean deviation (MD), and Glaucoma Hemifield Test (GHT) results. Most (50%) of the boys with hearing impairments had profound hearing impairments. There was no significant between-group difference in age (P = 0.49) or IQ (P = 0.13). There was no between-group difference in the corrected distance visual acuity (P = 0.183). According to the FT, MD, and GHT results, the percentage of boys with abnormal VFs in the hearing impairment group was significantly greater than that in the normal hearing group: 40.6% vs. 22.1%, 59.4% vs. 19.1%, and 31.2% vs. 8.8%, respectively (P < 0.0001). The mean MD in the hearing impairment group was significantly worse than that in the normal hearing group (-0.79 ± 2.04 and -4.61 ± 6.52 dB, respectively, P < 0.0001), and the mean FT was also significantly worse (38.97 ± 1.66 vs. 35.30 ± 1.43 dB, respectively, P <0.0001). Moreover, there was a significant between-group difference in the GHT results (P < 0.0001). Thus, there were higher percentages of boys with VF abnormalities and higher mean MD, FT, and GHT results among those with hearing impairments compared to those with normal hearing. These findings emphasize the need for detailed VF assessments for patients with hearing impairments. PMID:28293650

  19. Abnormal late visual responses and alpha oscillations in neurofibromatosis type 1: a link to visual and attention deficits

    PubMed Central

    2014-01-01

    Background Neurofibromatosis type 1 (NF1) affects several areas of cognitive function including visual processing and attention. We investigated the neural mechanisms underlying the visual deficits of children and adolescents with NF1 by studying visual evoked potentials (VEPs) and brain oscillations during visual stimulation and rest periods. Methods Electroencephalogram/event-related potential (EEG/ERP) responses were measured during visual processing (NF1 n = 17; controls n = 19) and idle periods with eyes closed and eyes open (NF1 n = 12; controls n = 14). Visual stimulation was chosen to bias activation of the three detection mechanisms: achromatic, red-green and blue-yellow. Results We found significant differences between the groups for late chromatic VEPs and a specific enhancement in the amplitude of the parieto-occipital alpha amplitude both during visual stimulation and idle periods. Alpha modulation and the negative influence of alpha oscillations in visual performance were found in both groups. Conclusions Our findings suggest abnormal later stages of visual processing and enhanced amplitude of alpha oscillations supporting the existence of deficits in basic sensory processing in NF1. Given the link between alpha oscillations, visual perception and attention, these results indicate a neural mechanism that might underlie the visual sensitivity deficits and increased lapses of attention observed in individuals with NF1. PMID:24559228

  20. The Puzzle of Visual Development: Behavior and Neural Limits.

    PubMed

    Kiorpes, Lynne

    2016-11-09

    The development of visual function takes place over many months or years in primate infants. Visual sensitivity is very poor near birth and improves over different times courses for different visual functions. The neural mechanisms that underlie these processes are not well understood despite many decades of research. The puzzle arises because research into the factors that limit visual function in infants has found surprisingly mature neural organization and adult-like receptive field properties in very young infants. The high degree of visual plasticity that has been documented during the sensitive period in young children and animals leaves the brain vulnerable to abnormal visual experience. Abnormal visual experience during the sensitive period can lead to amblyopia, a developmental disorder of vision affecting ∼3% of children. This review provides a historical perspective on research into visual development and the disorder amblyopia. The mismatch between the status of the primary visual cortex and visual behavior, both during visual development and in amblyopia, is discussed, and several potential resolutions are considered. It seems likely that extrastriate visual areas further along the visual pathways may set important limits on visual function and show greater vulnerability to abnormal visual experience. Analyses based on multiunit, population activity may provide useful representations of the information being fed forward from primary visual cortex to extrastriate processing areas and to the motor output. Copyright © 2016 the authors 0270-6474/16/3611384-10$15.00/0.

  1. Analysis and visualization of chromosomal abnormalities in SNP data with SNPscan

    PubMed Central

    Ting, Jason C; Ye, Ying; Thomas, George H; Ruczinski, Ingo; Pevsner, Jonathan

    2006-01-01

    Background A variety of diseases are caused by chromosomal abnormalities such as aneuploidies (having an abnormal number of chromosomes), microdeletions, microduplications, and uniparental disomy. High density single nucleotide polymorphism (SNP) microarrays provide information on chromosomal copy number changes, as well as genotype (heterozygosity and homozygosity). SNP array studies generate multiple types of data for each SNP site, some with more than 100,000 SNPs represented on each array. The identification of different classes of anomalies within SNP data has been challenging. Results We have developed SNPscan, a web-accessible tool to analyze and visualize high density SNP data. It enables researchers (1) to visually and quantitatively assess the quality of user-generated SNP data relative to a benchmark data set derived from a control population, (2) to display SNP intensity and allelic call data in order to detect chromosomal copy number anomalies (duplications and deletions), (3) to display uniparental isodisomy based on loss of heterozygosity (LOH) across genomic regions, (4) to compare paired samples (e.g. tumor and normal), and (5) to generate a file type for viewing SNP data in the University of California, Santa Cruz (UCSC) Human Genome Browser. SNPscan accepts data exported from Affymetrix Copy Number Analysis Tool as its input. We validated SNPscan using data generated from patients with known deletions, duplications, and uniparental disomy. We also inspected previously generated SNP data from 90 apparently normal individuals from the Centre d'Étude du Polymorphisme Humain (CEPH) collection, and identified three cases of uniparental isodisomy, four females having an apparently mosaic X chromosome, two mislabelled SNP data sets, and one microdeletion on chromosome 2 with mosaicism from an apparently normal female. These previously unrecognized abnormalities were all detected using SNPscan. The microdeletion was independently confirmed by

  2. Preserved local but disrupted contextual figure-ground influences in an individual with abnormal function of intermediate visual areas

    PubMed Central

    Brooks, Joseph L.; Gilaie-Dotan, Sharon; Rees, Geraint; Bentin, Shlomo; Driver, Jon

    2012-01-01

    Visual perception depends not only on local stimulus features but also on their relationship to the surrounding stimulus context, as evident in both local and contextual influences on figure-ground segmentation. Intermediate visual areas may play a role in such contextual influences, as we tested here by examining LG, a rare case of developmental visual agnosia. LG has no evident abnormality of brain structure and functional neuroimaging showed relatively normal V1 function, but his intermediate visual areas (V2/V3) function abnormally. We found that contextual influences on figure-ground organization were selectively disrupted in LG, while local sources of figure-ground influences were preserved. Effects of object knowledge and familiarity on figure-ground organization were also significantly diminished. Our results suggest that the mechanisms mediating contextual and familiarity influences on figure-ground organization are dissociable from those mediating local influences on figure-ground assignment. The disruption of contextual processing in intermediate visual areas may play a role in the substantial object recognition difficulties experienced by LG. PMID:22947116

  3. Abnormal early brain responses during visual search are evident in schizophrenia but not bipolar affective disorder.

    PubMed

    VanMeerten, Nicolaas J; Dubke, Rachel E; Stanwyck, John J; Kang, Seung Suk; Sponheim, Scott R

    2016-01-01

    People with schizophrenia show deficits in processing visual stimuli but neural abnormalities underlying the deficits are unclear and it is unknown whether such functional brain abnormalities are present in other severe mental disorders or in individuals who carry genetic liability for schizophrenia. To better characterize brain responses underlying visual search deficits and test their specificity to schizophrenia we gathered behavioral and electrophysiological responses during visual search (i.e., Span of Apprehension [SOA] task) from 38 people with schizophrenia, 31 people with bipolar disorder, 58 biological relatives of people with schizophrenia, 37 biological relatives of people with bipolar disorder, and 65 non-psychiatric control participants. Through subtracting neural responses associated with purely sensory aspects of the stimuli we found that people with schizophrenia exhibited reduced early posterior task-related neural responses (i.e., Span Endogenous Negativity [SEN]) while other groups showed normative responses. People with schizophrenia exhibited longer reaction times than controls during visual search but nearly identical accuracy. Those individuals with schizophrenia who had larger SENs performed more efficiently (i.e., shorter reaction times) on the SOA task suggesting that modulation of early visual cortical responses facilitated their visual search. People with schizophrenia also exhibited a diminished P300 response compared to other groups. Unaffected first-degree relatives of people with bipolar disorder and schizophrenia showed an amplified N1 response over posterior brain regions in comparison to other groups. Diminished early posterior brain responses are associated with impaired visual search in schizophrenia and appear to be specifically associated with the neuropathology of schizophrenia. Published by Elsevier B.V.

  4. Experience-dependent central vision deficits: Neurobiology and visual acuity.

    PubMed

    Williams, Kate; Balsor, Justin L; Beshara, Simon; Beston, Brett R; Jones, David G; Murphy, Kathryn M

    2015-09-01

    Abnormal visual experience during childhood often leads to amblyopia, with strong links to binocular dysfunction that can include poor acuity in both eyes, especially in central vision. In animal models of amblyopia, the non-deprived eye is often considered normal and what limits binocular acuity. This leaves open the question whether monocular deprivation (MD) induces binocular dysfunction similar to what is found in amblyopia. In previous studies of MD cats, we found a loss of excitatory receptors restricted to the central visual field representation in visual cortex (V1), including both eyes' columns. This led us to ask two questions about the effects of MD: how quickly are receptors lost in V1? and is there an impact on binocular acuity? We found that just a few hours of MD caused a rapid loss of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor proteins across all of V1. But after a few days of MD, there was recovery in the visual periphery, leaving a loss of AMPA receptors only in the central region of V1. We reared animals with early MD followed by a long period of binocular vision and found binocular acuity deficits that were greatest in the central visual field. Our results suggest that the greater binocular acuity deficits in the central visual field are driven in part by the long-term loss of AMPA receptors in the central region of V1. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. The two-visual-systems hypothesis and the perspectival features of visual experience.

    PubMed

    Foley, Robert T; Whitwell, Robert L; Goodale, Melvyn A

    2015-09-01

    Some critics of the two-visual-systems hypothesis (TVSH) argue that it is incompatible with the fundamentally egocentric nature of visual experience (what we call the 'perspectival account'). The TVSH proposes that the ventral stream, which delivers up our visual experience of the world, works in an allocentric frame of reference, whereas the dorsal stream, which mediates the visual control of action, uses egocentric frames of reference. Given that the TVSH is also committed to the claim that dorsal-stream processing does not contribute to the contents of visual experience, it has been argued that the TVSH cannot account for the egocentric features of our visual experience. This argument, however, rests on a misunderstanding about how the operations mediating action and the operations mediating perception are specified in the TVSH. In this article, we emphasize the importance of the 'outputs' of the two-systems to the specification of their respective operations. We argue that once this point is appreciated, it becomes evident that the TVSH is entirely compatible with a perspectival account of visual experience. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Modification of visual function by early visual experience.

    PubMed

    Blakemore, C

    1976-07-01

    Physiological experiments, involving recording from the visual cortex in young kittens and monkeys, have given new insight into human developmental disorders. In the visual cortex of normal cats and monkeys most neurones are selectively sensitive to the orientation of moving edges and they receive very similar signals from both eyes. Even in very young kittens without visual experience, most neurones are binocularly driven and a small proportion of them are genuinely orientation selective. There is no passive maturation of the system in the absence of visual experience, but even very brief exposure to patterned images produces rapid emergence of the adult organization. These results are compared to observations on humans who have "recovered" from early blindness. Covering one eye in a kitten or a monkey, during a sensitive period early in life, produces a virtually complete loss of input from that eye in the cortex. These results can be correlated with the production of "stimulus deprivation amblyopia" in infants who have had one eye patched. Induction of a strabismus causes a loss of binocularity in the visual cortex, and in humans it leads to a loss of stereoscopic vision and binocular fusion. Exposing kittens to lines of one orientation modifies the preferred orientations of cortical cells and there is an analogous "meridional amblyopia" in astigmatic humans. The existence of a sensitive period in human vision is discussed, as well as the possibility of designing remedial and preventive treatments for human developmental disorders.

  7. Women's experiences receiving abnormal prenatal chromosomal microarray testing results.

    PubMed

    Bernhardt, Barbara A; Soucier, Danielle; Hanson, Karen; Savage, Melissa S; Jackson, Laird; Wapner, Ronald J

    2013-02-01

    Genomic microarrays can detect copy-number variants not detectable by conventional cytogenetics. This technology is diffusing rapidly into prenatal settings even though the clinical implications of many copy-number variants are currently unknown. We conducted a qualitative pilot study to explore the experiences of women receiving abnormal results from prenatal microarray testing performed in a research setting. Participants were a subset of women participating in a multicenter prospective study "Prenatal Cytogenetic Diagnosis by Array-based Copy Number Analysis." Telephone interviews were conducted with 23 women receiving abnormal prenatal microarray results. We found that five key elements dominated the experiences of women who had received abnormal prenatal microarray results: an offer too good to pass up, blindsided by the results, uncertainty and unquantifiable risks, need for support, and toxic knowledge. As prenatal microarray testing is increasingly used, uncertain findings will be common, resulting in greater need for careful pre- and posttest counseling, and more education of and resources for providers so they can adequately support the women who are undergoing testing.

  8. Embodied experiences of prenatal diagnosis of fetal abnormality and pregnancy termination.

    PubMed

    Pitt, Penelope; McClaren, Belinda J; Hodgson, Jan

    2016-05-01

    Pregnant women routinely undergo prenatal screening in Australia and this has become a common experience of motherhood. When prenatal screening or prenatal testing results in diagnosis of a serious fetal abnormality, women are presented with a decision to continue or terminate their pregnancy. Few recent studies have explored women's psychosocial experience of prenatal diagnosis and pregnancy termination for fetal abnormality, and within this small group of studies it is rare for research to consider the embodied aspect of women's experiences. This paper reports on qualitative findings from in-depth interviews with 59 women in Melbourne, Australia who received a prenatal diagnosis of a significant abnormality and decided to terminate the pregnancy. Interview transcripts were coded inductively through thematic analysis. Two themes about embodiment were generated from the interviews: transitioning embodiment, and vulnerable bodies in un/comfortable spaces. Theory of pregnant embodiment was drawn on in interpreting women's narratives. Recommendations arising from the analysis include health professionals recognising, acknowledging and accommodating the transitioning embodied state of women as they consider, prepare for, undergo and recover from pregnancy termination for fetal abnormality. Further recommendations address the connections and disconnections between this transitioning embodied state and the spaces of clinics, hospitals and home. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Looking you in the mouth: abnormal gaze in autism resulting from impaired top-down modulation of visual attention.

    PubMed

    Neumann, Dirk; Spezio, Michael L; Piven, Joseph; Adolphs, Ralph

    2006-12-01

    People with autism are impaired in their social behavior, including their eye contact with others, but the processes that underlie this impairment remain elusive. We combined high-resolution eye tracking with computational modeling in a group of 10 high-functioning individuals with autism to address this issue. The group fixated the location of the mouth in facial expressions more than did matched controls, even when the mouth was not shown, even in faces that were inverted and most noticeably at latencies of 200-400 ms. Comparisons with a computational model of visual saliency argue that the abnormal bias for fixating the mouth in autism is not driven by an exaggerated sensitivity to the bottom-up saliency of the features, but rather by an abnormal top-down strategy for allocating visual attention.

  10. A comparison of visual and quantitative methods to identify interstitial lung abnormalities.

    PubMed

    Kliment, Corrine R; Araki, Tetsuro; Doyle, Tracy J; Gao, Wei; Dupuis, Josée; Latourelle, Jeanne C; Zazueta, Oscar E; Fernandez, Isis E; Nishino, Mizuki; Okajima, Yuka; Ross, James C; Estépar, Raúl San José; Diaz, Alejandro A; Lederer, David J; Schwartz, David A; Silverman, Edwin K; Rosas, Ivan O; Washko, George R; O'Connor, George T; Hatabu, Hiroto; Hunninghake, Gary M

    2015-10-29

    Evidence suggests that individuals with interstitial lung abnormalities (ILA) on a chest computed tomogram (CT) may have an increased risk to develop a clinically significant interstitial lung disease (ILD). Although methods used to identify individuals with ILA on chest CT have included both automated quantitative and qualitative visual inspection methods, there has been not direct comparison between these two methods. To investigate this relationship, we created lung density metrics and compared these to visual assessments of ILA. To provide a comparison between ILA detection methods based on visual assessment we generated measures of high attenuation areas (HAAs, defined by attenuation values between -600 and -250 Hounsfield Units) in >4500 participants from both the COPDGene and Framingham Heart studies (FHS). Linear and logistic regressions were used for analyses. Increased measures of HAAs (in ≥ 10 % of the lung) were significantly associated with ILA defined by visual inspection in both cohorts (P < 0.0001); however, the positive predictive values were not very high (19 % in COPDGene and 13 % in the FHS). In COPDGene, the association between HAAs and ILA defined by visual assessment were modified by the percentage of emphysema and body mass index. Although increased HAAs were associated with reductions in total lung capacity in both cohorts, there was no evidence for an association between measurement of HAAs and MUC5B promoter genotype in the FHS. Our findings demonstrate that increased measures of lung density may be helpful in determining the severity of lung volume reduction, but alone, are not strongly predictive of ILA defined by visual assessment. Moreover, HAAs were not associated with MUC5B promoter genotype.

  11. Asymmetrical Interhemispheric Connections Develop in Cat Visual Cortex after Early Unilateral Convergent Strabismus: Anatomy, Physiology, and Mechanisms

    PubMed Central

    Bui Quoc, Emmanuel; Ribot, Jérôme; Quenech’Du, Nicole; Doutremer, Suzette; Lebas, Nicolas; Grantyn, Alexej; Aushana, Yonane; Milleret, Chantal

    2011-01-01

    In the mammalian primary visual cortex, the corpus callosum contributes to the unification of the visual hemifields that project to the two hemispheres. Its development depends on visual experience. When this is abnormal, callosal connections must undergo dramatic anatomical and physiological changes. However, data concerning these changes are sparse and incomplete. Thus, little is known about the impact of abnormal postnatal visual experience on the development of callosal connections and their role in unifying representation of the two hemifields. Here, the effects of early unilateral convergent strabismus (a model of abnormal visual experience) were fully characterized with respect to the development of the callosal connections in cat visual cortex, an experimental model for humans. Electrophysiological responses and 3D reconstruction of single callosal axons show that abnormally asymmetrical callosal connections develop after unilateral convergent strabismus, resulting from an extension of axonal branches of specific orders in the hemisphere ipsilateral to the deviated eye and a decreased number of nodes and terminals in the other (ipsilateral to the non-deviated eye). Furthermore this asymmetrical organization prevents the establishment of a unifying representation of the two visual hemifields. As a general rule, we suggest that crossed and uncrossed retino-geniculo-cortical pathways contribute successively to the development of the callosal maps in visual cortex. PMID:22275883

  12. Experience and information loss in auditory and visual memory.

    PubMed

    Gloede, Michele E; Paulauskas, Emily E; Gregg, Melissa K

    2017-07-01

    Recent studies show that recognition memory for sounds is inferior to memory for pictures. Four experiments were conducted to examine the nature of auditory and visual memory. Experiments 1-3 were conducted to evaluate the role of experience in auditory and visual memory. Participants received a study phase with pictures/sounds, followed by a recognition memory test. Participants then completed auditory training with each of the sounds, followed by a second memory test. Despite auditory training in Experiments 1 and 2, visual memory was superior to auditory memory. In Experiment 3, we found that it is possible to improve auditory memory, but only after 3 days of specific auditory training and 3 days of visual memory decay. We examined the time course of information loss in auditory and visual memory in Experiment 4 and found a trade-off between visual and auditory recognition memory: Visual memory appears to have a larger capacity, while auditory memory is more enduring. Our results indicate that visual and auditory memory are inherently different memory systems and that differences in visual and auditory recognition memory performance may be due to the different amounts of experience with visual and auditory information, as well as structurally different neural circuitry specialized for information retention.

  13. Termination of pregnancy for fetal abnormality: a meta-ethnography of women's experiences.

    PubMed

    Lafarge, Caroline; Mitchell, Kathryn; Fox, Pauline

    2014-11-01

    Due to technological advances in antenatal diagnosis of fetal abnormalities, more women face the prospect of terminating pregnancies on these grounds. Much existing research focuses on women's psychological adaptation to this event. However, there is a lack of holistic understanding of women's experiences. This article reports a systematic review of qualitative studies into women's experiences of pregnancy termination for fetal abnormality. Eight databases were searched up to April 2014 for peer-reviewed studies, written in English, that reported primary or secondary data, used identifiable and interpretative qualitative methods, and offered a valuable contribution to the synthesis. Altogether, 4,281 records were screened; 14 met the inclusion criteria. The data were synthesised using meta-ethnography. Four themes were identified: a shattered world, losing and regaining control, the role of health professionals and the power of cultures. Pregnancy termination for fetal abnormality can be considered as a traumatic event that women experience as individuals, in their contact with the health professional community, and in the context of their politico-socio-legal environment. The range of emotions and experiences that pregnancy termination for fetal abnormality generates goes beyond the abortion paradigm and encompasses a bereavement model. Coordinated care pathways are needed that enable women to make their own decisions and receive supportive care. Copyright © 2014 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

  14. Development of visual category selectivity in ventral visual cortex does not require visual experience

    PubMed Central

    van den Hurk, Job; Van Baelen, Marc; Op de Beeck, Hans P.

    2017-01-01

    To what extent does functional brain organization rely on sensory input? Here, we show that for the penultimate visual-processing region, ventral-temporal cortex (VTC), visual experience is not the origin of its fundamental organizational property, category selectivity. In the fMRI study reported here, we presented 14 congenitally blind participants with face-, body-, scene-, and object-related natural sounds and presented 20 healthy controls with both auditory and visual stimuli from these categories. Using macroanatomical alignment, response mapping, and surface-based multivoxel pattern analysis, we demonstrated that VTC in blind individuals shows robust discriminatory responses elicited by the four categories and that these patterns of activity in blind subjects could successfully predict the visual categories in sighted controls. These findings were confirmed in a subset of blind participants born without eyes and thus deprived from all light perception since conception. The sounds also could be decoded in primary visual and primary auditory cortex, but these regions did not sustain generalization across modalities. Surprisingly, although not as strong as visual responses, selectivity for auditory stimulation in visual cortex was stronger in blind individuals than in controls. The opposite was observed in primary auditory cortex. Overall, we demonstrated a striking similarity in the cortical response layout of VTC in blind individuals and sighted controls, demonstrating that the overall category-selective map in extrastriate cortex develops independently from visual experience. PMID:28507127

  15. Enhanced visualization of abnormalities in digital-mammographic images

    NASA Astrophysics Data System (ADS)

    Young, Susan S.; Moore, William E.

    2002-05-01

    This paper describes two new presentation methods that are intended to improve the ability of radiologists to visualize abnormalities in mammograms by enhancing the appearance of the breast parenchyma pattern relative to the fatty-tissue surroundings. The first method, referred to as mountain- view, is obtained via multiscale edge decomposition through filter banks. The image is displayed in a multiscale edge domain that causes the image to have a topographic-like appearance. The second method displays the image in the intensity domain and is referred to as contrast-enhancement presentation. The input image is first passed through a decomposition filter bank to produce a filtered output (Id). The image at the lowest resolution is processed using a LUT (look-up table) to produce a tone scaled image (I'). The LUT is designed to optimally map the code value range corresponding to the parenchyma pattern in the mammographic image into the dynamic range of the output medium. The algorithm uses a contrast weight control mechanism to produce the desired weight factors to enhance the edge information corresponding to the parenchyma pattern. The output image is formed using a reconstruction filter bank through I' and enhanced Id.

  16. Developing Verbal and Visual Literacy through Experiences in the Visual Arts: 25 Tips for Teachers

    ERIC Educational Resources Information Center

    Johnson, Margaret H.

    2008-01-01

    Including talk about art--conversing with children about artwork, their own and others'--as a component of visual art activities extends children's experiences in and understanding of visual messages. Johnson discusses practices that help children develop visual and verbal expression through active experiences with the visual arts. She offers 25…

  17. Vitreoretinal interface abnormalities in middle-aged adults with visual impairment in the UK Biobank study: prevalence, impact on visual acuity and associations.

    PubMed

    McKibbin, Martin; Farragher, Tracey; Shickle, Darren

    2017-01-01

    The aim of this study was to determine the prevalence of vitreoretinal interface abnormalities (VRIA), the degree of visual impairment and associations with VRIA among adults, aged 40-69 years, in the UK Biobank study. Colour fundus photographs and spectral domain optical coherence tomography images were graded for 25% of the 8359 UK Biobank participants with mild visual impairment or worse (LogMAR >0.3 or Snellen <6/12) in at least one eye. The prevalence and contribution of VRIA to visual impairment was determined and multinomial logistic regression models were used to investigate association with known risk factors and other predetermined socioeconomic, biometric, lifestyle and medical variables for cases and matched controls. The minimum prevalence of any VRIA was 17.6% and 8.1% in the eyes with and without visual impairment, respectively. VRIA were identified as the primary cause of visual impairment in 3.6% of eyes. Although epiretinal membrane and vitreomacular traction were the most common VRIA, the degree of visual impairment was typically milder with these than with other VRIA. Visual impairment with a VRIA was positively associated with increasing age (relative risk ratio (RRR) 1.22 (95% CI 1.07 to 1.40)), female gender (RRR 1.28; 1.08 to 1.52) and Asian or Asian British ethnicity (RRR 1.60; 1.10 to 2.32). VRIA are common in middle-aged adults in the UK Biobank study, especially in eyes with visual impairment. VRIA were considered to be the primary cause of visual impairment in 3.6% of all eyes with visual impairment, although there was variation in the degree of visual impairment for each type of VRIA.

  18. Low-Intensity Repetitive Transcranial Magnetic Stimulation Improves Abnormal Visual Cortical Circuit Topography and Upregulates BDNF in Mice

    PubMed Central

    Makowiecki, Kalina; Harvey, Alan R.; Sherrard, Rachel M.

    2014-01-01

    Repetitive transcranial magnetic stimulation (rTMS) is increasingly used as a treatment for neurological and psychiatric disorders. Although the induced field is focused on a target region during rTMS, adjacent areas also receive stimulation at a lower intensity and the contribution of this perifocal stimulation to network-wide effects is poorly defined. Here, we examined low-intensity rTMS (LI-rTMS)-induced changes on a model neural network using the visual systems of normal (C57Bl/6J wild-type, n = 22) and ephrin-A2A5−/− (n = 22) mice, the latter possessing visuotopic anomalies. Mice were treated with LI-rTMS or sham (handling control) daily for 14 d, then fluorojade and fluororuby were injected into visual cortex. The distribution of dorsal LGN (dLGN) neurons and corticotectal terminal zones (TZs) was mapped and disorder defined by comparing their actual location with that predicted by injection sites. In the afferent geniculocortical projection, LI-rTMS decreased the abnormally high dispersion of retrogradely labeled neurons in the dLGN of ephrin-A2A5−/− mice, indicating geniculocortical map refinement. In the corticotectal efferents, LI-rTMS improved topography of the most abnormal TZs in ephrin-A2A5−/− mice without altering topographically normal TZs. To investigate a possible molecular mechanism for LI-rTMS-induced structural plasticity, we measured brain derived neurotrophic factor (BDNF) in the visual cortex and superior colliculus after single and multiple stimulations. BDNF was upregulated after a single stimulation for all groups, but only sustained in the superior colliculus of ephrin-A2A5−/− mice. Our results show that LI-rTMS upregulates BDNF, promoting a plastic environment conducive to beneficial reorganization of abnormal cortical circuits, information that has important implications for clinical rTMS. PMID:25100609

  19. Experience-enabled enhancement of adult visual cortex function.

    PubMed

    Tschetter, Wayne W; Alam, Nazia M; Yee, Christopher W; Gorz, Mario; Douglas, Robert M; Sagdullaev, Botir; Prusky, Glen T

    2013-03-20

    We previously reported in adult mice that visuomotor experience during monocular deprivation (MD) augmented enhancement of visual-cortex-dependent behavior through the non-deprived eye (NDE) during deprivation, and enabled enhanced function to persist after MD. We investigated the physiological substrates of this experience-enabled form of adult cortical plasticity by measuring visual behavior and visually evoked potentials (VEPs) in binocular visual cortex of the same mice before, during, and after MD. MD on its own potentiated VEPs contralateral to the NDE during MD and shifted ocular dominance (OD) in favor of the NDE in both hemispheres. Whereas we expected visuomotor experience during MD to augment these effects, instead enhanced responses contralateral to the NDE, and the OD shift ipsilateral to the NDE were attenuated. However, in the same animals, we measured NMDA receptor-dependent VEP potentiation ipsilateral to the NDE during MD, which persisted after MD. The results indicate that visuomotor experience during adult MD leads to enduring enhancement of behavioral function, not simply by amplifying MD-induced changes in cortical OD, but through an independent process of increasing NDE drive in ipsilateral visual cortex. Because the plasticity is resident in the mature visual cortex and selectively effects gain of visual behavior through experiential means, it may have the therapeutic potential to target and non-invasively treat eye- or visual-field-specific cortical impairment.

  20. Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.

    ERIC Educational Resources Information Center

    Fernald, Charles D.

    1980-01-01

    Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal.…

  1. Vitreoretinal interface abnormalities in middle-aged adults with visual impairment in the UK Biobank study: prevalence, impact on visual acuity and associations

    PubMed Central

    Farragher, Tracey; Shickle, Darren

    2017-01-01

    Objective The aim of this study was to determine the prevalence of vitreoretinal interface abnormalities (VRIA), the degree of visual impairment and associations with VRIA among adults, aged 40–69 years, in the UK Biobank study. Methods and analysis Colour fundus photographs and spectral domain optical coherence tomography images were graded for 25% of the 8359 UK Biobank participants with mild visual impairment or worse (LogMAR >0.3 or Snellen <6/12) in at least one eye. The prevalence and contribution of VRIA to visual impairment was determined and multinomial logistic regression models were used to investigate association with known risk factors and other predetermined socioeconomic, biometric, lifestyle and medical variables for cases and matched controls. Results The minimum prevalence of any VRIA was 17.6% and 8.1% in the eyes with and without visual impairment, respectively. VRIA were identified as the primary cause of visual impairment in 3.6% of eyes. Although epiretinal membrane and vitreomacular traction were the most common VRIA, the degree of visual impairment was typically milder with these than with other VRIA. Visual impairment with a VRIA was positively associated with increasing age (relative risk ratio (RRR) 1.22 (95% CI 1.07 to 1.40)), female gender (RRR 1.28; 1.08 to 1.52) and Asian or Asian British ethnicity (RRR 1.60; 1.10 to 2.32). Conclusions VRIA are common in middle-aged adults in the UK Biobank study, especially in eyes with visual impairment. VRIA were considered to be the primary cause of visual impairment in 3.6% of all eyes with visual impairment, although there was variation in the degree of visual impairment for each type of VRIA. PMID:29354705

  2. Retinal abnormalities in β-thalassemia major

    PubMed Central

    Bhoiwala, Devang L.; Dunaief, Joshua L.

    2015-01-01

    Patients with beta (β)-thalassemia (β-TM: thalassemia major, β-TI: thalassemia intermedia) have a variety of complications that may affect all organs, including the eye. Ocular abnormalities include retinal pigment epithelium degeneration, angioid streaks, venous tortuosity, night blindness, visual field defects, decreased visual acuity, color vision abnormalities, and acute visual loss. Patients with β-TM are transfusion dependent and require iron chelation therapy (ICT) in order to survive. Retinal degeneration may result from either retinal iron accumulation from transfusion-induced iron overload or retinal toxicity induced by ICT. Some who were never treated with ICT exhibited retinopathy, and others receiving ICT had chelator-induced retinopathy. We will focus on retinal abnormalities present in individuals with β-TM viewed in light of new findings on the mechanisms and manifestations of retinal iron toxicity. PMID:26325202

  3. Adaptive design of visual perception experiments

    NASA Astrophysics Data System (ADS)

    O'Connor, John D.; Hixson, Jonathan; Thomas, James M., Jr.; Peterson, Matthew S.; Parasuraman, Raja

    2010-04-01

    Meticulous experimental design may not always prevent confounds from affecting experimental data acquired during visual perception experiments. Although experimental controls reduce the potential effects of foreseen sources of interference, interaction, or noise, they are not always adequate for preventing the confounding effects of unforeseen forces. Visual perception experimentation is vulnerable to unforeseen confounds because of the nature of the associated cognitive processes involved in the decision task. Some confounds are beyond the control of experimentation, such as what a participant does immediately prior to experimental participation, or the participant's attitude or emotional state. Other confounds may occur through ignorance of practical control methods on the part of the experiment's designer. The authors conducted experiments related to experimental fatigue and initially achieved significant results that were, upon re-examination, attributable to a lack of adequate controls. Re-examination of the original results and the processes and events that led to them yielded a second experimental design with more experimental controls and significantly different results. The authors propose that designers of visual perception experiments can benefit from planning to use a test-fix-test or adaptive experimental design cycle, so that unforeseen confounds in the initial design can be remedied.

  4. Women's experiences of abnormal Pap smear results - A qualitative study.

    PubMed

    Rask, Marie; Swahnberg, Katarina; Lindell, Gunnel; Oscarsson, Marie

    2017-06-01

    To describe women's experiences of abnormal Pap smear result. Ten women were recruited from a women's health clinic. Qualitative interviews based on six open-ended questions were conducted, transcribed verbatim, and analyzed by content analysis. The women believed that their abnormal Pap smear result was indicative of having cancer. This created anxiety in the women, which resulted in the need for emotional support and information. Testing positive with human papillomavirus (HPV) also meant consequences for the relatives as well as concerns about the sexually transmitted nature of the virus. Finally, the women had a need to be treated with respect by the healthcare professionals in order to reduce feelings of being abused. In general, women have a low level of awareness of HPV and its relation to abnormal Pap smear results. Women who receive abnormal Pap smear results need oral information, based on the individual women's situation, and delivered at the time the women receive the test result. It is also essential that a good emotional contact be established between the women and the healthcare professionals. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. The effects of retinal abnormalities on the multifocal visual evoked potential.

    PubMed

    Chen, John Y; Hood, Donald C; Odel, Jeffrey G; Behrens, Myles M

    2006-10-01

    To examine the effects on the amplitude and latency of the multifocal visual evoked potential (mfVEP) in retinal diseases associated with depressed multifocal electroretinograms (mfERG). Static automated perimetry (SAP), mfERGs, and mfVEPs were obtained from 15 individuals seen by neuro-ophthalmologists and diagnosed with retinal disease based on funduscopic examination, visual field, and mfERG. Optic neuropathy was ruled out in all cases. Diagnoses included autoimmune retinopathy (n = 3), branch retinal arterial occlusion (n = 3), branch retinal vein occlusion (n = 1), vitamin A deficiency (n = 1), digoxin/age-related macular degeneration (n = 1), multiple evanescent white dot syndrome (n = 1), and nonspecific retinal disease (n = 5). Patients were selected from a larger group based on abnormal mfERG amplitudes covering a diameter of 20 degrees or greater. Fourteen (93%) of 15 patients showed significant mfVEP delays, as determined by either mean latency or the probability of a cluster of delayed local responses. Thirteen of 15 patients had normal mfVEP amplitudes in regions corresponding to markedly reduced or nonrecordable mfERG responses. These findings can be mimicked in normal individuals by viewing the display through a neutral-density filter. Retinal diseases can result in mfVEPs of relatively normal amplitudes, often with delays, in regions showing decreased mfERG responses and visual field sensitivity loss. Consequently, a retinal problem can be missed, or dismissed as functional, if a diagnosis is based on an mfVEP of normal or near-normal amplitude. Further, in patients with marked mfVEP delays, a retinal problem could be confused with optic neuritis, especially in a patient with a normal appearing fundus.

  6. The handicap of abnormal colour vision.

    PubMed

    Cole, Barry L

    2004-07-01

    All people with abnormal colour vision, except for a few mildly affected deuteranomals, report that they experience problems with colour in everyday life and at work. Contemporary society presents them with increasing problems because colour is now so widely used in printed materials and in computer displays. Equal opportunity law gives them protection against unfair discrimination in employment, so a decision to exclude a person from employment on the grounds of abnormal colour vision must now be well supported by good evidence and sound argument. This paper reviews the investigations that have contributed to understanding the nature and consequences of the problems they have. All those with abnormal colour vision are at a disadvantage with comparative colour tasks that involve precise matching of colours or discrimination of fine colour differences either because of their loss of colour discrimination or anomalous perception of metamers. The majority have problems when colour is used to code information, in man-made colour codes and in naturally occurring colour codes that signal ripeness of fruit, freshness of meat or illness. They can be denied the benefit of colour to mark out objects and organise complex visual displays. They may be unreliable when a colour name is used as an identifier. They are slower and less successful in search when colour is an attribute of the target object or is used to organise the visual display. Because those with the more severe forms of abnormal colour vision perceive a very limited gamut of colours, they are at a disadvantage in the pursuit and appreciation of those forms of art that use colour.

  7. US Navy Women's Experience of an Abnormal Cervical Cancer Screening.

    PubMed

    Braun, Lisa A; Kennedy, Holly Powell; Sadler, Lois S; Dixon, Jane; Womack, Julie; Wilson, Candy

    2016-01-01

    Recent policy revisions allow greater inclusion of military women in operational and/or deployable positions (ie, shipboard, overseas, and war zone duty assignments), but these positions can create unique health care challenges. Military members are often transient due to deployments and change of duty stations, impacting timely follow-up care for treatable health conditions. There has been minimal research on challenges or strategies in preventive health screening and follow-up for US military women. The purpose of this qualitative research study was to describe US Navy women's experiences with abnormal cervical cancer screenings requiring colposcopic follow-up care. Ship- and shored-based women receiving care at a military colposcopy clinic completed interviews about their experience. Two forms of narrative analysis, Labov's sociolinguistic structural analysis and Braun and Clarke's thematic analysis, were employed to gain a more robust understanding of the women's experiences. The sample was comprised of 26 women (16 ship-based, 10 shore-based). Five themes were identified: 1) It's like this bombshell (initial abnormal results notification); 2) I didn't understand (self-discovery process); 3) Freaked (emotional toll); 4) It's kind of like this back and forth (scheduling and navigating care); and 5) It really opened my eyes (lessons learned). The women's stories highlighted some issues unique to military health care, such as operational demands and follow-up care; other issues are likely common for most women learning about an abnormal cervical cancer screening result. Areas important for practice and future research include improving notification practices, providing information, understanding women's fear, and continuity of care. Research exploring educational initiatives and self-management practices are critical within military populations. © 2016 by the American College of Nurse-Midwives.

  8. Retinal abnormalities in β-thalassemia major.

    PubMed

    Bhoiwala, Devang L; Dunaief, Joshua L

    2016-01-01

    Patients with beta (β)-thalassemia (β-TM: β-thalassemia major, β-TI: β-thalassemia intermedia) have a variety of complications that may affect all organs, including the eye. Ocular abnormalities include retinal pigment epithelial degeneration, angioid streaks, venous tortuosity, night blindness, visual field defects, decreased visual acuity, color vision abnormalities, and acute visual loss. Patients with β-thalassemia major are transfusion dependent and require iron chelation therapy to survive. Retinal degeneration may result from either retinal iron accumulation from transfusion-induced iron overload or retinal toxicity induced by iron chelation therapy. Some who were never treated with iron chelation therapy exhibited retinopathy, and others receiving iron chelation therapy had chelator-induced retinopathy. We will focus on retinal abnormalities present in individuals with β-thalassemia major viewed in light of new findings on the mechanisms and manifestations of retinal iron toxicity. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Visual field changes after cataract extraction: the AGIS experience.

    PubMed

    Koucheki, Behrooz; Nouri-Mahdavi, Kouros; Patel, Gitane; Gaasterland, Douglas; Caprioli, Joseph

    2004-12-01

    To test the hypothesis that cataract extraction in glaucomatous eyes improves overall sensitivity of visual function without affecting the size or depth of glaucomatous scotomas. Experimental study with no control group. One hundred fifty-eight eyes (of 140 patients) from the Advanced Glaucoma Intervention Study with at least two reliable visual fields within a year both before and after cataract surgery were included. Average mean deviation (MD), pattern standard deviation (PSD), and corrected pattern standard deviation (CPSD) were compared before and after cataract extraction. To evaluate changes in scotoma size, the number of abnormal points (P < .05) on the pattern deviation plot was compared before and after surgery. We described an index ("scotoma depth index") to investigate changes of scotoma depth after surgery. Mean values for MD, PSD, and CPSD were -13.2, 6.4, and 5.9 dB before and -11.9, 6.8, and 6.2 dB after cataract surgery (P < or = .001 for all comparisons). Mean (+/- SD) number of abnormal points on pattern deviation plot was 26.7 +/- 9.4 and 27.5 +/- 9.0 before and after cataract surgery, respectively (P = .02). Scotoma depth index did not change after cataract extraction (-19.3 vs -19.2 dB, P = .90). Cataract extraction caused generalized improvement of the visual field, which was most marked in eyes with less advanced glaucomatous damage. Although the enlargement of scotomas was statistically significant, it was not clinically meaningful. No improvement of sensitivity was observed in the deepest part of the scotomas.

  10. Preattentive visual search and perceptual grouping in schizophrenia.

    PubMed

    Carr, V J; Dewis, S A; Lewin, T J

    1998-06-15

    To help determine whether patients with schizophrenia show deficits in the stimulus-based aspects of preattentive processing, we undertook a series of experiments within the framework of feature integration theory. Thirty subjects with a DSM-III-R diagnosis of schizophrenia and 30 age-, gender-, and education-matched normal control subjects completed two computerized experimental tasks, a visual search task assessing parallel and serial information processing (Experiment 1) and a task which examined the effects of perceptual grouping on visual search strategies (Experiment 2). We also assessed current symptomatology and its relationship to task performance. While the schizophrenia subjects had longer reaction times in Experiment 1, their overall pattern of performance across both experimental tasks was similar to that of the control subjects, and generally unrelated to current symptomatology. Predictions from feature integration theory about the impact of varying display size (Experiment 1) and number of perceptual groups (Experiment 2) on the detection of feature and conjunction targets were strongly supported. This study revealed no firm evidence that schizophrenia is associated with a preattentive abnormality in visual search using stimuli that differ on the basis of physical characteristics. While subject and task characteristics may partially account for differences between this and previous studies, it is more likely that preattentive processing abnormalities in schizophrenia may occur only under conditions involving selected 'top-down' factors such as context and meaning.

  11. 6th Yahya Cohen Lecture: visual experience during cataract surgery.

    PubMed

    Au Eong, K G

    2002-09-01

    The visual sensations many patients experience during cataract surgery under local anaesthesia have received little attention until recently. This paper reviews the recent studies on this phenomenon, discusses its clinical significance and suggests novel approaches to reduce its negative impact on the surgery. Literature review. Many patients who have cataract surgery under retrobulbar, peribulbar or topical anaesthesia experience a variety of visual sensations in their operated eye during surgery. These visual sensations include perception of light, movements, flashes, one or more colours, surgical instruments, the surgeon's hand/fingers, the surgeon and changes in light brightness. Some patients experience transient no light perception, even if the operation is performed under topical anaesthesia. The clinical significance of this phenomenon lies in the fact that approximately 7.1% to 15.4% of patients find their visual experience frightening. This fear and anxiety may cause some patients to become uncooperative during surgery and trigger a sympathetic surge, causing such undesirable effects as hypertension, tachycardia, ischaemic strain on the heart, hyperventilation and acute panic attack. Several approaches to reduce the negative impact of patients' visual experience are suggested, including appropriate preoperative counselling and reducing the ability of patients to see during surgery. The findings that some patients find their intraoperative visual experience distressing have a major impact on the way ophthalmologists manage their cataract patients. To reduce its negative impact, surgeons should consider incorporating appropriate preoperative counselling on potential intraoperative visual experience when obtaining informed consent for surgery.

  12. Neural mechanisms of oculomotor abnormalities in the infantile strabismus syndrome.

    PubMed

    Walton, Mark M G; Pallus, Adam; Fleuriet, Jérome; Mustari, Michael J; Tarczy-Hornoch, Kristina

    2017-07-01

    Infantile strabismus is characterized by numerous visual and oculomotor abnormalities. Recently nonhuman primate models of infantile strabismus have been established, with characteristics that closely match those observed in human patients. This has made it possible to study the neural basis for visual and oculomotor symptoms in infantile strabismus. In this review, we consider the available evidence for neural abnormalities in structures related to oculomotor pathways ranging from visual cortex to oculomotor nuclei. These studies provide compelling evidence that a disturbance of binocular vision during a sensitive period early in life, whatever the cause, results in a cascade of abnormalities through numerous brain areas involved in visual functions and eye movements. Copyright © 2017 the American Physiological Society.

  13. Audiovisual plasticity following early abnormal visual experience: Reduced McGurk effect in people with one eye.

    PubMed

    Moro, Stefania S; Steeves, Jennifer K E

    2018-04-13

    Previously, we have shown that people who have had one eye surgically removed early in life during visual development have enhanced sound localization [1] and lack visual dominance, commonly observed in binocular and monocular (eye-patched) viewing controls [2]. Despite these changes, people with one eye integrate auditory and visual components of multisensory events optimally [3]. The current study investigates how people with one eye perceive the McGurk effect, an audiovisual illusion where a new syllable is perceived when visual lip movements do not match the corresponding sound [4]. We compared individuals with one eye to binocular and monocular viewing controls and found that they have a significantly smaller McGurk effect compared to binocular controls. Additionally, monocular controls tended to perceive the McGurk effect less often than binocular controls suggesting a small transient modulation of the McGurk effect. These results suggest altered weighting of the auditory and visual modalities with both short and long-term monocular viewing. These results indicate the presence of permanent adaptive perceptual accommodations in people who have lost one eye early in life that may serve to mitigate the loss of binocularity during early brain development. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  14. Online least squares one-class support vector machines-based abnormal visual event detection.

    PubMed

    Wang, Tian; Chen, Jie; Zhou, Yi; Snoussi, Hichem

    2013-12-12

    The abnormal event detection problem is an important subject in real-time video surveillance. In this paper, we propose a novel online one-class classification algorithm, online least squares one-class support vector machine (online LS-OC-SVM), combined with its sparsified version (sparse online LS-OC-SVM). LS-OC-SVM extracts a hyperplane as an optimal description of training objects in a regularized least squares sense. The online LS-OC-SVM learns a training set with a limited number of samples to provide a basic normal model, then updates the model through remaining data. In the sparse online scheme, the model complexity is controlled by the coherence criterion. The online LS-OC-SVM is adopted to handle the abnormal event detection problem. Each frame of the video is characterized by the covariance matrix descriptor encoding the moving information, then is classified into a normal or an abnormal frame. Experiments are conducted, on a two-dimensional synthetic distribution dataset and a benchmark video surveillance dataset, to demonstrate the promising results of the proposed online LS-OC-SVM method.

  15. Online Least Squares One-Class Support Vector Machines-Based Abnormal Visual Event Detection

    PubMed Central

    Wang, Tian; Chen, Jie; Zhou, Yi; Snoussi, Hichem

    2013-01-01

    The abnormal event detection problem is an important subject in real-time video surveillance. In this paper, we propose a novel online one-class classification algorithm, online least squares one-class support vector machine (online LS-OC-SVM), combined with its sparsified version (sparse online LS-OC-SVM). LS-OC-SVM extracts a hyperplane as an optimal description of training objects in a regularized least squares sense. The online LS-OC-SVM learns a training set with a limited number of samples to provide a basic normal model, then updates the model through remaining data. In the sparse online scheme, the model complexity is controlled by the coherence criterion. The online LS-OC-SVM is adopted to handle the abnormal event detection problem. Each frame of the video is characterized by the covariance matrix descriptor encoding the moving information, then is classified into a normal or an abnormal frame. Experiments are conducted, on a two-dimensional synthetic distribution dataset and a benchmark video surveillance dataset, to demonstrate the promising results of the proposed online LS-OC-SVM method. PMID:24351629

  16. Visualizing how cancer chromosome abnormalities form in living cells

    Cancer.gov

    For the first time, scientists have directly observed events that lead to the formation of a chromosome abnormality that is often found in cancer cells. The abnormality, called a translocation, occurs when part of a chromosome breaks off and becomes attac

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

    PubMed

    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.

  18. Real-Time Strategy Video Game Experience and Visual Perceptual Learning.

    PubMed

    Kim, Yong-Hwan; Kang, Dong-Wha; Kim, Dongho; Kim, Hye-Jin; Sasaki, Yuka; Watanabe, Takeo

    2015-07-22

    Visual perceptual learning (VPL) is defined as long-term improvement in performance on a visual-perception task after visual experiences or training. Early studies have found that VPL is highly specific for the trained feature and location, suggesting that VPL is associated with changes in the early visual cortex. However, the generality of visual skills enhancement attributable to action video-game experience suggests that VPL can result from improvement in higher cognitive skills. If so, experience in real-time strategy (RTS) video-game play, which may heavily involve cognitive skills, may also facilitate VPL. To test this hypothesis, we compared VPL between RTS video-game players (VGPs) and non-VGPs (NVGPs) and elucidated underlying structural and functional neural mechanisms. Healthy young human subjects underwent six training sessions on a texture discrimination task. Diffusion-tensor and functional magnetic resonance imaging were performed before and after training. VGPs performed better than NVGPs in the early phase of training. White-matter connectivity between the right external capsule and visual cortex and neuronal activity in the right inferior frontal gyrus (IFG) and anterior cingulate cortex (ACC) were greater in VGPs than NVGPs and were significantly correlated with RTS video-game experience. In both VGPs and NVGPs, there was task-related neuronal activity in the right IFG, ACC, and striatum, which was strengthened after training. These results indicate that RTS video-game experience, associated with changes in higher-order cognitive functions and connectivity between visual and cognitive areas, facilitates VPL in early phases of training. The results support the hypothesis that VPL can occur without involvement of only visual areas. Significance statement: Although early studies found that visual perceptual learning (VPL) is associated with involvement of the visual cortex, generality of visual skills enhancement by action video-game experience

  19. Wide-field fundus autofluorescence abnormalities and visual function in patients with cone and cone-rod dystrophies.

    PubMed

    Oishi, Maho; Oishi, Akio; Ogino, Ken; Makiyama, Yukiko; Gotoh, Norimoto; Kurimoto, Masafumi; Yoshimura, Nagahisa

    2014-05-20

    To evaluate the clinical utility of wide-field fundus autofluorescence (FAF) in patients with cone dystrophy and cone-rod dystrophy. Sixteen patients with cone dystrophy (CD) and 41 patients with cone-rod dystrophy (CRD) were recruited at one institution. The right eye of each patient was included for analysis. We obtained wide-field FAF images using a ultra-widefield retinal imaging device and measured the area of abnormal FAF. The association between the area of abnormal FAF and the results of visual acuity measurements, kinetic perimetry, and electroretinography (ERG) were investigated. The mean age of the participants was 51.4 ± 17.4 years, and the mean logarithm of the minimum angle of resolution was 1.00 ± 0.57. The area of abnormal FAF correlated with the scotoma measured by the Goldman perimetry I/4e isopter (ρ = 0.79, P < 0.001). The area also correlated with amplitudes of the rod ERG (ρ = -0.63, P < 0.001), combined ERG a-wave (ρ = -0.72, P < 0.001), combined ERG b-wave (ρ = -0.66, P < 0.001), cone ERG (ρ = -0.44, P = 0.001), and flicker ERG (ρ = -0.47, P < 0.001). The extent of abnormal FAF reflects the severity of functional impairment in patients with cone-dominant retinal dystrophies. Fundus autofluorescence measurements are useful for predicting retinal function in these patients. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  20. Binocular combination in abnormal binocular vision

    PubMed Central

    Ding, Jian; Klein, Stanley A.; Levi, Dennis M.

    2013-01-01

    We investigated suprathreshold binocular combination in humans with abnormal binocular visual experience early in life. In the first experiment we presented the two eyes with equal but opposite phase shifted sine waves and measured the perceived phase of the cyclopean sine wave. Normal observers have balanced vision between the two eyes when the two eyes' images have equal contrast (i.e., both eyes contribute equally to the perceived image and perceived phase = 0°). However, in observers with strabismus and/or amblyopia, balanced vision requires a higher contrast image in the nondominant eye (NDE) than the dominant eye (DE). This asymmetry between the two eyes is larger than predicted from the contrast sensitivities or monocular perceived contrast of the two eyes and is dependent on contrast and spatial frequency: more asymmetric with higher contrast and/or spatial frequency. Our results also revealed a surprising NDE-to-DE enhancement in some of our abnormal observers. This enhancement is not evident in normal vision because it is normally masked by interocular suppression. However, in these abnormal observers the NDE-to-DE suppression was weak or absent. In the second experiment, we used the identical stimuli to measure the perceived contrast of a cyclopean grating by matching the binocular combined contrast to a standard contrast presented to the DE. These measures provide strong constraints for model fitting. We found asymmetric interocular interactions in binocular contrast perception, which was dependent on both contrast and spatial frequency in the same way as in phase perception. By introducing asymmetric parameters to the modified Ding-Sperling model including interocular contrast gain enhancement, we succeeded in accounting for both binocular combined phase and contrast simultaneously. Adding binocular contrast gain control to the modified Ding-Sperling model enabled us to predict the results of dichoptic and binocular contrast discrimination experiments

  1. Binocular combination in abnormal binocular vision.

    PubMed

    Ding, Jian; Klein, Stanley A; Levi, Dennis M

    2013-02-08

    We investigated suprathreshold binocular combination in humans with abnormal binocular visual experience early in life. In the first experiment we presented the two eyes with equal but opposite phase shifted sine waves and measured the perceived phase of the cyclopean sine wave. Normal observers have balanced vision between the two eyes when the two eyes' images have equal contrast (i.e., both eyes contribute equally to the perceived image and perceived phase = 0°). However, in observers with strabismus and/or amblyopia, balanced vision requires a higher contrast image in the nondominant eye (NDE) than the dominant eye (DE). This asymmetry between the two eyes is larger than predicted from the contrast sensitivities or monocular perceived contrast of the two eyes and is dependent on contrast and spatial frequency: more asymmetric with higher contrast and/or spatial frequency. Our results also revealed a surprising NDE-to-DE enhancement in some of our abnormal observers. This enhancement is not evident in normal vision because it is normally masked by interocular suppression. However, in these abnormal observers the NDE-to-DE suppression was weak or absent. In the second experiment, we used the identical stimuli to measure the perceived contrast of a cyclopean grating by matching the binocular combined contrast to a standard contrast presented to the DE. These measures provide strong constraints for model fitting. We found asymmetric interocular interactions in binocular contrast perception, which was dependent on both contrast and spatial frequency in the same way as in phase perception. By introducing asymmetric parameters to the modified Ding-Sperling model including interocular contrast gain enhancement, we succeeded in accounting for both binocular combined phase and contrast simultaneously. Adding binocular contrast gain control to the modified Ding-Sperling model enabled us to predict the results of dichoptic and binocular contrast discrimination experiments

  2. Experience, Context, and the Visual Perception of Human Movement

    ERIC Educational Resources Information Center

    Jacobs, Alissa; Pinto, Jeannine; Shiffrar, Maggie

    2004-01-01

    Why are human observers particularly sensitive to human movement? Seven experiments examined the roles of visual experience and motor processes in human movement perception by comparing visual sensitivities to point-light displays of familiar, unusual, and impossible gaits across gait-speed and identity discrimination tasks. In both tasks, visual…

  3. Audio-visual speech experience with age influences perceived audio-visual asynchrony in speech.

    PubMed

    Alm, Magnus; Behne, Dawn

    2013-10-01

    Previous research indicates that perception of audio-visual (AV) synchrony changes in adulthood. Possible explanations for these age differences include a decline in hearing acuity, a decline in cognitive processing speed, and increased experience with AV binding. The current study aims to isolate the effect of AV experience by comparing synchrony judgments from 20 young adults (20 to 30 yrs) and 20 normal-hearing middle-aged adults (50 to 60 yrs), an age range for which a decline of cognitive processing speed is expected to be minimal. When presented with AV stop consonant syllables with asynchronies ranging from 440 ms audio-lead to 440 ms visual-lead, middle-aged adults showed significantly less tolerance for audio-lead than young adults. Middle-aged adults also showed a greater shift in their point of subjective simultaneity than young adults. Natural audio-lead asynchronies are arguably more predictable than natural visual-lead asynchronies, and this predictability may render audio-lead thresholds more prone to experience-related fine-tuning.

  4. Abnormal Selective Attention Normalizes P3 Amplitudes in PDD

    ERIC Educational Resources Information Center

    Hoeksma, Marco R.; Kemner, Chantal; Kenemans, J. Leon; van Engeland, Herman

    2006-01-01

    This paper studied whether abnormal P3 amplitudes in PDD are a corollary of abnormalities in ERP components related to selective attention in visual and auditory tasks. Furthermore, this study sought to clarify possible age differences in such abnormalities. Children with PDD showed smaller P3 amplitudes than controls, but no abnormalities in…

  5. Experience Report: Visual Programming in the Real World

    NASA Technical Reports Server (NTRS)

    Baroth, E.; Hartsough, C

    1994-01-01

    This paper reports direct experience with two commercial, widely used visual programming environments. While neither of these systems is object oriented, the tools have transformed the development process and indicate a direction for visual object oriented tools to proceed.

  6. Experiences of Students with Visual Impairments in Canadian Higher Education

    ERIC Educational Resources Information Center

    Reed, Maureen; Curtis, Kathryn

    2012-01-01

    Introduction: This article presents a study of the higher education experiences of students with visual impairments in Canada. Methods: Students with visual impairments and the staff members of disability programs were surveyed and interviewed regarding the students' experiences in entering higher education and completing their higher education…

  7. Development of the Visual Word Form Area Requires Visual Experience: Evidence from Blind Braille Readers

    PubMed Central

    Kanjlia, Shipra; Merabet, Lotfi B.

    2017-01-01

    Learning to read causes the development of a letter- and word-selective region known as the visual word form area (VWFA) within the human ventral visual object stream. Why does a reading-selective region develop at this anatomical location? According to one hypothesis, the VWFA develops at the nexus of visual inputs from retinotopic cortices and linguistic input from the frontotemporal language network because reading involves extracting linguistic information from visual symbols. Surprisingly, the anatomical location of the VWFA is also active when blind individuals read Braille by touch, suggesting that vision is not required for the development of the VWFA. In this study, we tested the alternative prediction that VWFA development is in fact influenced by visual experience. We predicted that in the absence of vision, the “VWFA” is incorporated into the frontotemporal language network and participates in high-level language processing. Congenitally blind (n = 10, 9 female, 1 male) and sighted control (n = 15, 9 female, 6 male), male and female participants each took part in two functional magnetic resonance imaging experiments: (1) word reading (Braille for blind and print for sighted participants), and (2) listening to spoken sentences of different grammatical complexity (both groups). We find that in blind, but not sighted participants, the anatomical location of the VWFA responds both to written words and to the grammatical complexity of spoken sentences. This suggests that in blindness, this region takes on high-level linguistic functions, becoming less selective for reading. More generally, the current findings suggest that experience during development has a major effect on functional specialization in the human cortex. SIGNIFICANCE STATEMENT The visual word form area (VWFA) is a region in the human cortex that becomes specialized for the recognition of written letters and words. Why does this particular brain region become specialized for reading? We

  8. Peripersonal space representation develops independently from visual experience.

    PubMed

    Ricciardi, Emiliano; Menicagli, Dario; Leo, Andrea; Costantini, Marcello; Pietrini, Pietro; Sinigaglia, Corrado

    2017-12-15

    Our daily-life actions are typically driven by vision. When acting upon an object, we need to represent its visual features (e.g. shape, orientation, etc.) and to map them into our own peripersonal space. But what happens with people who have never had any visual experience? How can they map object features into their own peripersonal space? Do they do it differently from sighted agents? To tackle these questions, we carried out a series of behavioral experiments in sighted and congenitally blind subjects. We took advantage of a spatial alignment effect paradigm, which typically refers to a decrease of reaction times when subjects perform an action (e.g., a reach-to-grasp pantomime) congruent with that afforded by a presented object. To systematically examine peripersonal space mapping, we presented visual or auditory affording objects both within and outside subjects' reach. The results showed that sighted and congenitally blind subjects did not differ in mapping objects into their own peripersonal space. Strikingly, this mapping occurred also when objects were presented outside subjects' reach, but within the peripersonal space of another agent. This suggests that (the lack of) visual experience does not significantly affect the development of both one's own and others' peripersonal space representation.

  9. Gamma abnormalities during perception of illusory figures in autism.

    PubMed

    Brown, Caroline; Gruber, Thomas; Boucher, Jill; Rippon, Gina; Brock, Jon

    2005-06-01

    This experiment was designed to test the hypothesis that perceptual abnormalities in autism might be associated with alteration of induced gamma activity patterns overlying visual cortical regions. EEG was recorded from six adolescents with autism and eight controls matched on chronological age, and verbal and nonverbal mental age, whilst identifying the presence or absence of an illusory Kanizsa shape. Although there were no reaction time or accuracy differences between the groups there were significant task-related differences in cortical activity. Control participants showed typical gamma-band activity over parietal regions at around 350 msec post onset of shape trials, similar to gamma patterns found in previous studies with non-impaired adults. In contrast, autistic participants showed overall increased activity, including an early 100 msec gamma peak and a late induced peak, 50 to 70 msec earlier than that shown by the control group. We interpret the abnormal gamma activity to reflect decreased "signal to noise" due to decreased inhibitory processing. In this experiment we did not establish a link between altered perception and abnormal gamma, as the autistic participants' behaviour did not differ from the controls. Future work should be designed to replicate this phenomenon and establish the perceptual consequences of altered gamma activity.

  10. The Social Experiences of High School Students with Visual Impairments

    ERIC Educational Resources Information Center

    Jessup, Glenda; Bundy, Anita C.; Broom, Alex; Hancock, Nicola

    2017-01-01

    Introduction: This study explores the social experiences in high school of students with visual impairments. Methods: Experience sampling methodology was used to examine (a) how socially included students with visual impairments feel, (b) the internal qualities of their activities, and (c) the factors that influence a sense of inclusion. Twelve…

  11. Abnormal uterine bleeding unrelated to structural uterine abnormalities: management in the perimenopausal period.

    PubMed

    Sabbioni, Lorenzo; Zanetti, Isabella; Orlandini, Cinzia; Petraglia, Felice; Luisi, Stefano

    2017-02-01

    Abnormal uterine bleeding (AUB) is one of the commonest health problems encountered by women and a frequent phenomenon during menopausal transition. The clinical management of AUB must follow a standardized classification system to obtain the better diagnostic pathway and the optimal therapy. The PALM-COEIN classification system has been approved by the International Federation of Gynecology and Obstetrics (FIGO); it recognizes structural causes of AUB, which can be measured visually with imaging techniques or histopathology, and non-structural entities such as coagulopathies, ovulatory dysfunctions, endometrial and iatrogenic causes and disorders not yet classified. In this review we aim to evaluate the management of nonstructural causes of AUB during the menopausal transition, when commonly women experience changes in menstrual bleeding patterns and unexpected bleedings which affect their quality of life.

  12. Visualization experiences and issues in Deep Space Exploration

    NASA Technical Reports Server (NTRS)

    Wright, John; Burleigh, Scott; Maruya, Makoto; Maxwell, Scott; Pischel, Rene

    2003-01-01

    The panelists will discuss their experiences in collecting data in deep space, transmitting it to Earth, processing and visualizing it here, and using the visualization to drive the continued mission. This closes the loop, making missions more responsive to their environment, particularly in-situ operations on planetary surfaces and within planetary atmospheres.

  13. Electroretinography and Visual Evoked Potentials in Childhood Brain Tumor Survivors.

    PubMed

    Pietilä, Sari; Lenko, Hanna L; Oja, Sakari; Koivisto, Anna-Maija; Pietilä, Timo; Mäkipernaa, Anne

    2016-07-01

    This population-based cross-sectional study evaluates the clinical value of electroretinography and visual evoked potentials in childhood brain tumor survivors. A flash electroretinography and a checkerboard reversal pattern visual evoked potential (or alternatively a flash visual evoked potential) were done for 51 survivors (age 3.8-28.7 years) after a mean follow-up time of 7.6 (1.5-15.1) years. Abnormal electroretinography was obtained in 1 case, bilaterally delayed abnormal visual evoked potentials in 22/51 (43%) cases. Nine of 25 patients with infratentorial tumor location, and altogether 12 out of 31 (39%) patients who did not have tumors involving the visual pathways, had abnormal visual evoked potentials. Abnormal electroretinographies are rarely observed, but abnormal visual evoked potentials are common even without evident anatomic lesions in the visual pathway. Bilateral changes suggest a general and possibly multifactorial toxic/adverse effect on the visual pathway. Electroretinography and visual evoked potential may have clinical and scientific value while evaluating long-term effects of childhood brain tumors and tumor treatment. © The Author(s) 2016.

  14. Visualizing desirable patient healthcare experiences.

    PubMed

    Liu, Sandra S; Kim, Hyung T; Chen, Jie; An, Lingling

    2010-01-01

    High healthcare cost has drawn much attention and healthcare service providers (HSPs) are expected to deliver high-quality and consistent care. Therefore, an intimate understanding of the most desirable experience from a patient's and/or family's perspective as well as effective mapping and communication of such findings should facilitate HSPs' efforts in attaining sustainable competitive advantage in an increasingly discerning environment. This study describes (a) the critical quality attributes (CQAs) of the experience desired by patients and (b) the application of two visualization tools that are relatively new to the healthcare sector, namely the "spider-web diagram" and "promotion and detraction matrix." The visualization tools are tested with primary data collected from telephone surveys of 1,800 patients who had received care during calendar year 2005 at 6 of 61 hospitals within St. Louis, Missouri-based, Ascension Health. Five CQAs were found by factor analysis. The spider-web diagram illustrates that communication and empowerment and compassionate and respectful care are the most important CQAs, and accordingly, the promotion and detraction matrix shows those attributes that have the greatest effect for creating promoters, preventing detractors, and improving consumer's likelihood to recommend the healthcare provider.

  15. The Objective Identification and Quantification of Interstitial Lung Abnormalities in Smokers.

    PubMed

    Ash, Samuel Y; Harmouche, Rola; Ross, James C; Diaz, Alejandro A; Hunninghake, Gary M; Putman, Rachel K; Onieva, Jorge; Martinez, Fernando J; Choi, Augustine M; Lynch, David A; Hatabu, Hiroto; Rosas, Ivan O; Estepar, Raul San Jose; Washko, George R

    2017-08-01

    Previous investigation suggests that visually detected interstitial changes in the lung parenchyma of smokers are highly clinically relevant and predict outcomes, including death. Visual subjective analysis to detect these changes is time-consuming, insensitive to subtle changes, and requires training to enhance reproducibility. Objective detection of such changes could provide a method of disease identification without these limitations. The goal of this study was to develop and test a fully automated image processing tool to objectively identify radiographic features associated with interstitial abnormalities in the computed tomography scans of a large cohort of smokers. An automated tool that uses local histogram analysis combined with distance from the pleural surface was used to detect radiographic features consistent with interstitial lung abnormalities in computed tomography scans from 2257 individuals from the Genetic Epidemiology of COPD study, a longitudinal observational study of smokers. The sensitivity and specificity of this tool was determined based on its ability to detect the visually identified presence of these abnormalities. The tool had a sensitivity of 87.8% and a specificity of 57.5% for the detection of interstitial lung abnormalities, with a c-statistic of 0.82, and was 100% sensitive and 56.7% specific for the detection of the visual subtype of interstitial abnormalities called fibrotic parenchymal abnormalities, with a c-statistic of 0.89. In smokers, a fully automated image processing tool is able to identify those individuals who have interstitial lung abnormalities with moderate sensitivity and specificity. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  16. Development of the Visual Word Form Area Requires Visual Experience: Evidence from Blind Braille Readers.

    PubMed

    Kim, Judy S; Kanjlia, Shipra; Merabet, Lotfi B; Bedny, Marina

    2017-11-22

    Learning to read causes the development of a letter- and word-selective region known as the visual word form area (VWFA) within the human ventral visual object stream. Why does a reading-selective region develop at this anatomical location? According to one hypothesis, the VWFA develops at the nexus of visual inputs from retinotopic cortices and linguistic input from the frontotemporal language network because reading involves extracting linguistic information from visual symbols. Surprisingly, the anatomical location of the VWFA is also active when blind individuals read Braille by touch, suggesting that vision is not required for the development of the VWFA. In this study, we tested the alternative prediction that VWFA development is in fact influenced by visual experience. We predicted that in the absence of vision, the "VWFA" is incorporated into the frontotemporal language network and participates in high-level language processing. Congenitally blind ( n = 10, 9 female, 1 male) and sighted control ( n = 15, 9 female, 6 male), male and female participants each took part in two functional magnetic resonance imaging experiments: (1) word reading (Braille for blind and print for sighted participants), and (2) listening to spoken sentences of different grammatical complexity (both groups). We find that in blind, but not sighted participants, the anatomical location of the VWFA responds both to written words and to the grammatical complexity of spoken sentences. This suggests that in blindness, this region takes on high-level linguistic functions, becoming less selective for reading. More generally, the current findings suggest that experience during development has a major effect on functional specialization in the human cortex. SIGNIFICANCE STATEMENT The visual word form area (VWFA) is a region in the human cortex that becomes specialized for the recognition of written letters and words. Why does this particular brain region become specialized for reading? We

  17. Visual abnormalities associated with enhanced optic nerve myelination.

    PubMed

    Yu, Minzhong; Narayanan, S Priyadarshini; Wang, Feng; Morse, Emily; Macklin, Wendy B; Peachey, Neal S

    2011-02-16

    Expression of the constitutively active serine/threonine kinase Akt in oligodendrocytes results in enhanced myelination in the CNS. Here, we have examined the effects of this Akt overexpression on optic nerve structure and on optic nerve function, assessed using the visual evoked potential (VEP). Transgenic mice have been generated with the Plp promoter driving expression of a modified form of Akt, in which aspartic acids are substituted for Thr308 and Ser473. These Plp-Akt-DD (Akt-DD) mice, and littermate controls, were studied at different ages. Optic nerves were examined anatomically at 2 and 6 months of age. At 2 months of age, optic nerves were substantially thicker in Akt-DD mice, reflecting an increase in myelination of optic nerve axons. By electron microscopy, myelin thickness was increased in Akt-DD optic nerve, with extended paranodal domains having excess paranodal loops, and the density of nodes of Ranvier was reduced, relative to control mice. We recorded VEPs in response to strobe flash ganzfeld stimuli presented after overnight dark- and light-adapted conditions at ages ranging from 1 to 10 months. It was possible to record a clear VEP from Akt-DD mice at all ages examined. At 1 month of age, VEP implicit times were somewhat shorter in Akt-DD transgenic mice than in control animals. Beyond 6months of age, VEP latencies were consistently delayed in Akt-DD transgenic mice. These abnormalities did not reflect an alteration in retinal function as there were no significant differences between ERGs obtained from control or Akt-DD transgenic mice. In young mice, the somewhat faster responses may reflect improved transmission due to increased myelination of optic nerve axons. In older mice, where the Akt-DD optic nerve is markedly thicker than control, it is remarkable that optic nerves continue to function. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Visual cortex activity predicts subjective experience after reading books with colored letters.

    PubMed

    Colizoli, Olympia; Murre, Jaap M J; Scholte, H Steven; van Es, Daniel M; Knapen, Tomas; Rouw, Romke

    2016-07-29

    One of the most astonishing properties of synesthesia is that the evoked concurrent experiences are perceptual. Is it possible to acquire similar effects after learning cross-modal associations that resemble synesthetic mappings? In this study, we examine whether brain activation in early visual areas can be directly related to letter-color associations acquired by training. Non-synesthetes read specially prepared books with colored letters for several weeks and were scanned using functional magnetic resonance imaging. If the acquired letter-color associations were visual in nature, then brain activation in visual cortex while viewing the trained black letters (compared to untrained black letters) should predict the strength of the associations, the quality of the color experience, or the vividness of visual mental imagery. Results showed that training-related activation of area V4 was correlated with differences in reported subjective color experience. Trainees who were classified as having stronger 'associator' types of color experiences also had more negative activation for trained compared to untrained achromatic letters in area V4. In contrast, the strength of the acquired associations (measured as the Stroop effect) was not reliably reflected in visual cortex activity. The reported vividness of visual mental imagery was related to veridical color activation in early visual cortex, but not to the acquired color associations. We show for the first time that subjective experience related to a synesthesia-training paradigm was reflected in visual brain activation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Visual processing in anorexia nervosa and body dysmorphic disorder: similarities, differences, and future research directions

    PubMed Central

    Madsen, Sarah K.; Bohon, Cara; Feusner, Jamie D.

    2013-01-01

    Anorexia nervosa (AN) and body dysmorphic disorder (BDD) are psychiatric disorders that involve distortion of the experience of one’s physical appearance. In AN, individuals believe that they are overweight, perceive their body as “fat,” and are preoccupied with maintaining a low body weight. In BDD, individuals are preoccupied with misperceived defects in physical appearance, most often of the face. Distorted visual perception may contribute to these cardinal symptoms, and may be a common underlying phenotype. This review surveys the current literature on visual processing in AN and BDD, addressing lower- to higher-order stages of visual information processing and perception. We focus on peer-reviewed studies of AN and BDD that address ophthalmologic abnormalities, basic neural processing of visual input, integration of visual input with other systems, neuropsychological tests of visual processing, and representations of whole percepts (such as images of faces, bodies, and other objects). The literature suggests a pattern in both groups of over-attention to detail, reduced processing of global features, and a tendency to focus on symptom-specific details in their own images (body parts in AN, facial features in BDD), with cognitive strategy at least partially mediating the abnormalities. Visuospatial abnormalities were also evident when viewing images of others and for non-appearance related stimuli. Unfortunately no study has directly compared AN and BDD, and most studies were not designed to disentangle disease-related emotional responses from lower-order visual processing. We make recommendations for future studies to improve the understanding of visual processing abnormalities in AN and BDD. PMID:23810196

  20. Optic nerve dysfunction during gravity inversion. Visual field abnormalities.

    PubMed

    Sanborn, G E; Friberg, T R; Allen, R

    1987-06-01

    Inversion in a head-down position (gravity inversion) results in an intraocular pressure of 35 to 40 mm Hg in normal subjects. We used computerized static perimetry to measure the visual fields of normal subjects during gravity inversion. There were no visual field changes in the central 6 degrees of the visual field compared with the baseline (preinversion) values. However, when the central 30 degrees of the visual field was tested, reversible visual field defects were found in 11 of 19 eyes. We believe that the substantial elevation of intraocular pressure during gravity inversion may pose potential risks to the eyes, and we recommend that inversion for extended periods of time be avoided.

  1. Which visual functions depend on intermediate visual regions? Insights from a case of developmental visual form agnosia.

    PubMed

    Gilaie-Dotan, Sharon

    2016-03-01

    A key question in visual neuroscience is the causal link between specific brain areas and perceptual functions; which regions are necessary for which visual functions? While the contribution of primary visual cortex and high-level visual regions to visual perception has been extensively investigated, the contribution of intermediate visual areas (e.g. V2/V3) to visual processes remains unclear. Here I review more than 20 visual functions (early, mid, and high-level) of LG, a developmental visual agnosic and prosopagnosic young adult, whose intermediate visual regions function in a significantly abnormal fashion as revealed through extensive fMRI and ERP investigations. While expectedly, some of LG's visual functions are significantly impaired, some of his visual functions are surprisingly normal (e.g. stereopsis, color, reading, biological motion). During the period of eight-year testing described here, LG trained on a perceptual learning paradigm that was successful in improving some but not all of his visual functions. Following LG's visual performance and taking into account additional findings in the field, I propose a framework for how different visual areas contribute to different visual functions, with an emphasis on intermediate visual regions. Thus, although rewiring and plasticity in the brain can occur during development to overcome and compensate for hindering developmental factors, LG's case seems to indicate that some visual functions are much less dependent on strict hierarchical flow than others, and can develop normally in spite of abnormal mid-level visual areas, thereby probably less dependent on intermediate visual regions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Youth with Visual Impairments: Experiences in General Physical Education

    ERIC Educational Resources Information Center

    Lieberman, Lauren J.; Robinson, Barbara L.; Rollheiser, Heidi

    2006-01-01

    The rapid increase in the number of students with visual impairments currently being educated in inclusive general physical education makes it important that physical education instructors know how best to serve them. Assessment of the experiences of students with visual impairments during general physical education classes, knowledge of students'…

  3. Women with abnormal Pap smear result: a qualitative study of Swedish healthcare professionals' experiences.

    PubMed

    Rask, M; Oscarsson, M; Lindell, G; Swahnberg, K

    2016-11-01

    A Papanicolaou (Pap) smear can be used to detect pre-cancerous cellular changes, so that they can be treated before they develop into cervical cancer. When the results of a Pap smear test are abnormal, women need further investigation, treatment and follow-up. Healthcare professionals (HCPs) are in a position to care for these women with abnormalities. The aim of this study was to explore the experiences of HCPs in caring for women with abnormal Pap smear results. In total, 20 HCPs from two counties in south-eastern Sweden participated in individual interviews, based on two open-ended questions. Interviews were recorded, transcribed verbatim and analysed using content analysis. The results showed that HCPs experienced that abnormal Pap smear results created anxiety in women, who often sought information from the Internet as a way to cope. Furthermore, the HCPs thought that it was a problem that women chose not to attend investigation, treatment and follow-ups. However, information about the seriousness of abnormal Pap smear results causes women to participate. It is a challenge for HCPs to inform in a reassuring manner. Finally, HCPs should collaborate with women to meet their information needs and to also provide support regarding finding and filtering reliable information on the Internet. © 2015 John Wiley & Sons Ltd.

  4. Tobacco Induced Mutations: A Fun, Visually Impressive Experiment

    ERIC Educational Resources Information Center

    Milholland, Rebecca B. R.; Hines, Stefani D.

    2004-01-01

    A modified version "Tobacco Induced Mutations" of Ames assay experiment provides a meaningful context for students to learn about the concept of mutations by using a known carcinogen that is tobacco. This experiment shows toxicological concept of the dose/response relationship and visually demonstrates when a mutation have occurred in bacteria…

  5. Brain and bone abnormalities of thanatophoric dwarfism.

    PubMed

    Miller, Elka; Blaser, Susan; Shannon, Patrick; Widjaja, Elysa

    2009-01-01

    The purpose of this article is to present the imaging findings of skeletal and brain abnormalities in thanatophoric dwarfism, a lethal form of dysplastic dwarfism. The bony abnormalities associated with thanatophoric dwarfism include marked shortening of the tubular bones and ribs. Abnormal temporal lobe development is a common associated feature and can be visualized as early as the second trimester. It is important to assess the brains of fetuses with suspected thanatophoric dwarfism because the presence of associated brain malformations can assist in the antenatal diagnosis of thanatophoric dwarfism.

  6. Food experiences and eating patterns of visually impaired and blind people.

    PubMed

    Bilyk, Marie Claire; Sontrop, Jessica M; Chapman, Gwen E; Barr, Susan I; Mamer, Linda

    2009-01-01

    The number of visually impaired and blind Canadians will rise dramatically as our population ages, and yet little is known about the impact of blindness on the experience of food and eating. In this qualitative study, the food experiences and eating patterns of visually impaired and blind people were examined. Influencing factors were also explored. In 2000, nine blind or severely visually impaired subjects were recruited through blindness-related organizations in British Columbia. Participants completed individual semi-structured, in-depth interviews. These were transcribed verbatim, coded, and analyzed to explicate participants' experiences. Participants experienced blindness-related obstacles when shopping for food, preparing food, and eating in restaurants. Inaccessible materials and environments left participants with a diet lacking in variety and limited access to physical activity. Seven participants were overweight or obese, a finding that may be related to limited physical activity and higher-than-average restaurant use. This is the first study in which the experience of food and eating is described from the perspective of visually impaired Canadians. Nutrition and blindness professionals must work together to reduce the food-related obstacles faced by visually impaired and blind people. Professionals must address both individual skill development and social and structural inequities.

  7. Experience-dependent plasticity from eye opening enables lasting, visual cortex-dependent enhancement of motion vision.

    PubMed

    Prusky, Glen T; Silver, Byron D; Tschetter, Wayne W; Alam, Nazia M; Douglas, Robert M

    2008-09-24

    Developmentally regulated plasticity of vision has generally been associated with "sensitive" or "critical" periods in juvenile life, wherein visual deprivation leads to loss of visual function. Here we report an enabling form of visual plasticity that commences in infant rats from eye opening, in which daily threshold testing of optokinetic tracking, amid otherwise normal visual experience, stimulates enduring, visual cortex-dependent enhancement (>60%) of the spatial frequency threshold for tracking. The perceptual ability to use spatial frequency in discriminating between moving visual stimuli is also improved by the testing experience. The capacity for inducing enhancement is transitory and effectively limited to infancy; however, enhanced responses are not consolidated and maintained unless in-kind testing experience continues uninterrupted into juvenile life. The data show that selective visual experience from infancy can alone enable visual function. They also indicate that plasticity associated with visual deprivation may not be the only cause of developmental visual dysfunction, because we found that experientially inducing enhancement in late infancy, without subsequent reinforcement of the experience in early juvenile life, can lead to enduring loss of function.

  8. Lenticular abnormalities in children.

    PubMed

    Khokhar, Sudarshan; Agarwal, Tushar; Kumar, Gaurav; Kushmesh, Rakhi; Tejwani, Lalit Kumar

    2012-01-01

    To study the lenticular problems in children presenting at an apex institute. Retrospective analysis of records (< 14 years) of new lens clinic cases was done. Of 1,047 children, 687 were males. Mean age at presentation was 6.35 ± 4.13 years. Developmental cataract was seen in 45.6% and posttraumatic cataract in 29.7% of patients. Other abnormalities were cataract with retinal detachment, persistent hyperplastic primary vitreous, subluxated lens, micro/spherophakia, cataract secondary to uveitis, intraocular lens complications, cataract with choroidal coloboma, and visual axis opacification. Developmental and posttraumatic cataracts were the most common abnormalities. Delayed presentation is of concern. Copyright 2012, SLACK Incorporated.

  9. The right cerebral hemisphere: emotion, music, visual-spatial skills, body-image, dreams, and awareness.

    PubMed

    Joseph, R

    1988-09-01

    Based on a review of numerous studies conducted on normal, neurosurgical and brain-injured individuals, the right cerebral hemisphere appears to be dominant in the perception and identification of environmental and nonverbal sounds; the analysis of geometric and visual space (e.g., depth perception, visual closure); somesthesis, stereognosis, the maintenance of the body image; the production of dreams during REM sleep; the perception of most aspects of musical stimuli; and the comprehension and expression of prosodic, melodic, visual, facial, and verbal emotion. When the right hemisphere is damaged a variety of cognitive abnormalities may result, including hemi-inattention and neglect, prosopagnosia, constructional apraxia, visual-perceptual disturbances, and agnosia for environmental, musical, and emotional sounds. Similarly, a myriad of affective abnormalities may occur, including indifference, depression, hysteria, gross social-emotional disinhibition, florid manic excitement, childishness, euphoria, impulsivity, and abnormal sexual behavior. Patients may become delusional, engage in the production of bizzare confabulations and experience a host of somatic disturbances such as pain and body-perceptual distortions. Based on studies of normal and "split-brain" functioning, it also appears that the right hemisphere maintains a highly developed social-emotional mental system and can independently perceive, recall and act on certain memories and experiences without the aid or active reflective participation of the left. This leads to situations in which the right and left halves of the brain sometime act in an uncooperative fashion, which gives rise to inter-manual and intra-psychic conflicts.

  10. Cortical activation during Braille reading is influenced by early visual experience in subjects with severe visual disability: a correlational fMRI study.

    PubMed

    Melzer, P; Morgan, V L; Pickens, D R; Price, R R; Wall, R S; Ebner, F F

    2001-11-01

    Functional magnetic resonance imaging was performed on blind adults resting and reading Braille. The strongest activation was found in primary somatic sensory/motor cortex on both cortical hemispheres. Additional foci of activation were situated in the parietal, temporal, and occipital lobes where visual information is processed in sighted persons. The regions were differentiated most in the correlation of their time courses of activation with resting and reading. Differences in magnitude and expanse of activation were substantially less significant. Among the traditionally visual areas, the strength of correlation was greatest in posterior parietal cortex and moderate in occipitotemporal, lateral occipital, and primary visual cortex. It was low in secondary visual cortex as well as in dorsal and ventral inferior temporal cortex and posterior middle temporal cortex. Visual experience increased the strength of correlation in all regions except dorsal inferior temporal and posterior parietal cortex. The greatest statistically significant increase, i.e., approximately 30%, was in ventral inferior temporal and posterior middle temporal cortex. In these regions, words are analyzed semantically, which may be facilitated by visual experience. In contrast, visual experience resulted in a slight, insignificant diminution of the strength of correlation in dorsal inferior temporal cortex where language is analyzed phonetically. These findings affirm that posterior temporal regions are engaged in the processing of written language. Moreover, they suggest that this function is modified by early visual experience. Furthermore, visual experience significantly strengthened the correlation of activation and Braille reading in occipital regions traditionally involved in the processing of visual features and object recognition suggesting a role for visual imagery. Copyright 2001 Wiley-Liss, Inc.

  11. Visual experience sculpts whole-cortex spontaneous infraslow activity patterns through an Arc-dependent mechanism

    PubMed Central

    Kraft, Andrew W.; Mitra, Anish; Bauer, Adam Q.; Raichle, Marcus E.; Culver, Joseph P.; Lee, Jin-Moo

    2017-01-01

    Decades of work in experimental animals has established the importance of visual experience during critical periods for the development of normal sensory-evoked responses in the visual cortex. However, much less is known concerning the impact of early visual experience on the systems-level organization of spontaneous activity. Human resting-state fMRI has revealed that infraslow fluctuations in spontaneous activity are organized into stereotyped spatiotemporal patterns across the entire brain. Furthermore, the organization of spontaneous infraslow activity (ISA) is plastic in that it can be modulated by learning and experience, suggesting heightened sensitivity to change during critical periods. Here we used wide-field optical intrinsic signal imaging in mice to examine whole-cortex spontaneous ISA patterns. Using monocular or binocular visual deprivation, we examined the effects of critical period visual experience on the development of ISA correlation and latency patterns within and across cortical resting-state networks. Visual modification with monocular lid suturing reduced correlation between left and right cortices (homotopic correlation) within the visual network, but had little effect on internetwork correlation. In contrast, visual deprivation with binocular lid suturing resulted in increased visual homotopic correlation and increased anti-correlation between the visual network and several extravisual networks, suggesting cross-modal plasticity. These network-level changes were markedly attenuated in mice with genetic deletion of Arc, a gene known to be critical for activity-dependent synaptic plasticity. Taken together, our results suggest that critical period visual experience induces global changes in spontaneous ISA relationships, both within the visual network and across networks, through an Arc-dependent mechanism. PMID:29087327

  12. Astronaut Charles Conrad during visual acuity experiments over Laredo

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronaut Charles Conrad Jr., pilot for the prime crew on the Gemini 5 space flight, takes pictures of predetermined land areas during visual acuity experiments over Laredo, Texas. The experiments will aid in learning to identify known terrestrial features under controlled conditions.

  13. Development of cortical orientation selectivity in the absence of visual experience with contour

    PubMed Central

    Hussain, Shaista; Weliky, Michael

    2011-01-01

    Visual cortical neurons are selective for the orientation of lines, and the full development of this selectivity requires natural visual experience after eye opening. Here we examined whether this selectivity develops without seeing lines and contours. Juvenile ferrets were reared in a dark room and visually trained by being shown a movie of flickering, sparse spots. We found that despite the lack of contour visual experience, the cortical neurons of these ferrets developed strong orientation selectivity and exhibited simple-cell receptive fields. This finding suggests that overt contour visual experience is unnecessary for the maturation of orientation selectivity and is inconsistent with the computational models that crucially require the visual inputs of lines and contours for the development of orientation selectivity. We propose that a correlation-based model supplemented with a constraint on synaptic strength dynamics is able to account for our experimental result. PMID:21753023

  14. Linguistic experience and audio-visual perception of non-native fricatives.

    PubMed

    Wang, Yue; Behne, Dawn M; Jiang, Haisheng

    2008-09-01

    This study examined the effects of linguistic experience on audio-visual (AV) perception of non-native (L2) speech. Canadian English natives and Mandarin Chinese natives differing in degree of English exposure [long and short length of residence (LOR) in Canada] were presented with English fricatives of three visually distinct places of articulation: interdentals nonexistent in Mandarin and labiodentals and alveolars common in both languages. Stimuli were presented in quiet and in a cafe-noise background in four ways: audio only (A), visual only (V), congruent AV (AVc), and incongruent AV (AVi). Identification results showed that overall performance was better in the AVc than in the A or V condition and better in quiet than in cafe noise. While the Mandarin long LOR group approximated the native English patterns, the short LOR group showed poorer interdental identification, more reliance on visual information, and greater AV-fusion with the AVi materials, indicating the failure of L2 visual speech category formation with the short LOR non-natives and the positive effects of linguistic experience with the long LOR non-natives. These results point to an integrated network in AV speech processing as a function of linguistic background and provide evidence to extend auditory-based L2 speech learning theories to the visual domain.

  15. Cone Photoreceptor Abnormalities Correlate with Vision Loss in Patients with Stargardt Disease

    PubMed Central

    Chen, Yingming; Ratnam, Kavitha; Sundquist, Sanna M.; Lujan, Brandon; Ayyagari, Radha; Gudiseva, V. Harini; Roorda, Austin

    2011-01-01

    Purpose. To study the relationship between macular cone structure, fundus autofluorescence (AF), and visual function in patients with Stargardt disease (STGD). Methods. High-resolution images of the macula were obtained with adaptive optics scanning laser ophthalmoscopy (AOSLO) and spectral domain optical coherence tomography in 12 patients with STGD and 27 age-matched healthy subjects. Measures of retinal structure and AF were correlated with visual function, including best-corrected visual acuity, color vision, kinetic and static perimetry, fundus-guided microperimetry, and full-field electroretinography. Mutation analysis of the ABCA4 gene was completed in all patients. Results. Patients were 15 to 55 years old, and visual acuity ranged from 20/25–20/320. Central scotomas were present in all patients, although the fovea was spared in three patients. The earliest cone spacing abnormalities were observed in regions of homogeneous AF, normal visual function, and normal outer retinal structure. Outer retinal structure and AF were most normal near the optic disc. Longitudinal studies showed progressive increases in AF followed by reduced AF associated with losses of visual sensitivity, outer retinal layers, and cones. At least one disease-causing mutation in the ABCA4 gene was identified in 11 of 12 patients studied; 1 of 12 patients showed no disease-causing ABCA4 mutations. Conclusions. AOSLO imaging demonstrated abnormal cone spacing in regions of abnormal fundus AF and reduced visual function. These findings provide support for a model of disease progression in which lipofuscin accumulation results in homogeneously increased AF with cone spacing abnormalities, followed by heterogeneously increased AF with cone loss, then reduced AF with cone and RPE cell death. (ClinicalTrials.gov number, NCT00254605.) PMID:21296825

  16. Resting-State Retinotopic Organization in the Absence of Retinal Input and Visual Experience

    PubMed Central

    Binda, Paola; Benson, Noah C.; Bridge, Holly; Watkins, Kate E.

    2015-01-01

    Early visual areas have neuronal receptive fields that form a sampling mosaic of visual space, resulting in a series of retinotopic maps in which the same region of space is represented in multiple visual areas. It is not clear to what extent the development and maintenance of this retinotopic organization in humans depend on retinal waves and/or visual experience. We examined the corticocortical receptive field organization of resting-state BOLD data in normally sighted, early blind, and anophthalmic (in which both eyes fail to develop) individuals and found that resting-state correlations between V1 and V2/V3 were retinotopically organized for all subject groups. These results show that the gross retinotopic pattern of resting-state connectivity across V1-V3 requires neither retinal waves nor visual experience to develop and persist into adulthood. SIGNIFICANCE STATEMENT Evidence from resting-state BOLD data suggests that the connections between early visual areas develop and are maintained even in the absence of retinal waves and visual experience. PMID:26354906

  17. Absence of visual experience modifies the neural basis of numerical thinking.

    PubMed

    Kanjlia, Shipra; Lane, Connor; Feigenson, Lisa; Bedny, Marina

    2016-10-04

    In humans, the ability to reason about mathematical quantities depends on a frontoparietal network that includes the intraparietal sulcus (IPS). How do nature and nurture give rise to the neurobiology of numerical cognition? We asked how visual experience shapes the neural basis of numerical thinking by studying numerical cognition in congenitally blind individuals. Blind (n = 17) and blindfolded sighted (n = 19) participants solved math equations that varied in difficulty (e.g., 27 - 12 = x vs. 7 - 2 = x), and performed a control sentence comprehension task while undergoing fMRI. Whole-cortex analyses revealed that in both blind and sighted participants, the IPS and dorsolateral prefrontal cortices were more active during the math task than the language task, and activity in the IPS increased parametrically with equation difficulty. Thus, the classic frontoparietal number network is preserved in the total absence of visual experience. However, surprisingly, blind but not sighted individuals additionally recruited a subset of early visual areas during symbolic math calculation. The functional profile of these "visual" regions was identical to that of the IPS in blind but not sighted individuals. Furthermore, in blindness, number-responsive visual cortices exhibited increased functional connectivity with prefrontal and IPS regions that process numbers. We conclude that the frontoparietal number network develops independently of visual experience. In blindness, this number network colonizes parts of deafferented visual cortex. These results suggest that human cortex is highly functionally flexible early in life, and point to frontoparietal input as a mechanism of cross-modal plasticity in blindness.

  18. Abnormal Time Experiences in Major Depression: An Empirical Qualitative Study.

    PubMed

    Stanghellini, Giovanni; Ballerini, Massimo; Presenza, Simona; Mancini, Milena; Northoff, Georg; Cutting, John

    2017-01-01

    Phenomenological psychopathology, through theoretical and idiographic studies, conceptualizes major depressive disorder (MDD) as a disorder of time experience. Investigations on abnormal time experience (ATE) in MDD adopting methodologies requested by the standards of empirical sciences are still lacking. Our study aimed to provide a qualitative analysis, on an empirical ground and on a large scale, of narratives of temporal experiences of persons affected by MDD. We interviewed 550 consecutive patients affected by affective and schizophrenic disorders. Clinical files were analysed by means of consensual qualitative research. Out of 100 MDD patients, 96 reported at least 1 ATE. The principal categories of ATE are vital retardation - the experience of a stagnation of endogenous vital processes (37 patients), the experience of present and future dominated by the past (29 patients), and the experience of the slackening of the flow oftime (25 patients). A comparison with ATE in schizophrenia patients showed that in MDD, unlike in schizophrenia, there is no disarticulation of time experience (disorder of temporal synthesis) but rather a disorder of conation or inhibition of becoming. The interview style was not meant to make a quantitative assessment ("false negatives" cannot be excluded). Our findings confirm the relevance of distinctive features of ATE in MDD, support the hypothesis of an intrinsic disordered temporal structure in depressive symptoms, and may have direct implications in clinical practice, especially in relation to differential diagnosis, setting the boundaries between "true" and milder forms of depression, and neurobiological research. © 2016 S. Karger AG, Basel.

  19. Patient DF's visual brain in action: Visual feedforward control in visual form agnosia.

    PubMed

    Whitwell, Robert L; Milner, A David; Cavina-Pratesi, Cristiana; Barat, Masihullah; Goodale, Melvyn A

    2015-05-01

    Patient DF, who developed visual form agnosia following ventral-stream damage, is unable to discriminate the width of objects, performing at chance, for example, when asked to open her thumb and forefinger a matching amount. Remarkably, however, DF adjusts her hand aperture to accommodate the width of objects when reaching out to pick them up (grip scaling). While this spared ability to grasp objects is presumed to be mediated by visuomotor modules in her relatively intact dorsal stream, it is possible that it may rely abnormally on online visual or haptic feedback. We report here that DF's grip scaling remained intact when her vision was completely suppressed during grasp movements, and it still dissociated sharply from her poor perceptual estimates of target size. We then tested whether providing trial-by-trial haptic feedback after making such perceptual estimates might improve DF's performance, but found that they remained significantly impaired. In a final experiment, we re-examined whether DF's grip scaling depends on receiving veridical haptic feedback during grasping. In one condition, the haptic feedback was identical to the visual targets. In a second condition, the haptic feedback was of a constant intermediate width while the visual target varied trial by trial. Despite this incongruent feedback, DF still scaled her grip aperture to the visual widths of the target blocks, showing only normal adaptation to the false haptically-experienced width. Taken together, these results strengthen the view that DF's spared grasping relies on a normal mode of dorsal-stream functioning, based chiefly on visual feedforward processing. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Abnormal global processing along the dorsal visual pathway in autism: a possible mechanism for weak visuospatial coherence?

    PubMed

    Pellicano, Elizabeth; Gibson, Lisa; Maybery, Murray; Durkin, Kevin; Badcock, David R

    2005-01-01

    Frith and Happe (Frith, U., & Happe, F. (1994). Autism: Beyond theory of mind. Cognition, 50, 115-132) argue that individuals with autism exhibit 'weak central coherence': an inability to integrate elements of information into coherent wholes. Some authors have speculated that a high-level impairment might be present in the dorsal visual pathway in autism, and furthermore, that this might account for weak central coherence, at least at the visuospatial level. We assessed the integrity of the dorsal visual pathway in children diagnosed with an autism spectrum disorder (ASD), and in typically developing children, using two visual tasks, one examining functioning at higher levels of the dorsal cortical stream (Global Dot Motion (GDM)), and the other assessing lower-level dorsal stream functioning (Flicker Contrast Sensitivity (FCS)). Central coherence was tested using the Children's Embedded Figures Test (CEFT). Relative to the typically developing children, the children with ASD had shorter CEFT latencies and higher GDM thresholds but equivalent FCS thresholds. Additionally, CEFT latencies were inversely related to GDM thresholds in the ASD group. These outcomes indicate that the elevated global motion thresholds in autism are the result of high-level impairments in dorsal cortical regions. Weak visuospatial coherence in autism may be in the form of abnormal cooperative mechanisms in extra-striate cortical areas, which might contribute to differential performance when processing stimuli as Gestalts, including both dynamic (i.e., global motion perception) and static (i.e., disembedding performance) stimuli.

  1. Visualization techniques for tongue analysis in traditional Chinese medicine

    NASA Astrophysics Data System (ADS)

    Pham, Binh L.; Cai, Yang

    2004-05-01

    Visual inspection of the tongue has been an important diagnostic method of Traditional Chinese Medicine (TCM). Clinic data have shown significant connections between various viscera cancers and abnormalities in the tongue and the tongue coating. Visual inspection of the tongue is simple and inexpensive, but the current practice in TCM is mainly experience-based and the quality of the visual inspection varies between individuals. The computerized inspection method provides quantitative models to evaluate color, texture and surface features on the tongue. In this paper, we investigate visualization techniques and processes to allow interactive data analysis with the aim to merge computerized measurements with human expert's diagnostic variables based on five-scale diagnostic conditions: Healthy (H), History Cancers (HC), History of Polyps (HP), Polyps (P) and Colon Cancer (C).

  2. Understanding the patient-provider communication needs and experiences of Latina and non-Latina White women following an abnormal mammogram.

    PubMed

    Molina, Yamile; Hohl, Sarah D; Ko, Linda K; Rodriguez, Edgar A; Thompson, Beti; Beresford, Shirley A A

    2014-12-01

    Latinas are more likely to delay recommended follow-up care than non-Latina White (NLW) women after an abnormal mammogram result. Ethnic differences in communication needs and experiences with health-care staff and providers may contribute to these delays as well as satisfaction with care. Nonetheless, little research has explored the aspects of communication that may contribute to patient comprehension, adherence to follow-up care, and satisfaction across ethnicity. The purpose of this exploratory, qualitative study was to identify patients' communication needs and experiences with follow-up care among Latina and NLW women who received an abnormal mammogram. We conducted 41 semi-structured interviews with 19 Latina and 22 NLW women between the ages of 40 and 74 who had received an abnormal mammogram. Communication themes indicated that women's needs and experiences concerning abnormal mammograms and follow-up care varied across ethnicity. Latinas and NLW women appeared to differ in their comprehension of abnormal results and follow-up care as a result of language barriers and health literacy. Both groups of women identified clear, empathic communication as being important in patient-provider communication; however, Latinas underscored the need for warm communicative styles, and NLW women emphasized the importance of providing more information. Women with high levels of satisfaction with patient-provider interactions appeared to have positive perspectives of subsequent screening and cancer treatment. To improve patient satisfaction and adherence to follow-up care among Latinas, educational programs are necessary to counsel health-care professionals with regard to language, health literacy, and empathic communication needs in health-care service delivery.

  3. Electrophysiological abnormalities associated with extensive myelinated retinal nerve fibers.

    PubMed

    Tay, Su Ann; Sanjay, Srinivasan

    2012-07-01

    An observational case report of electrophysiological abnormalities in a patient with anisomyopic amblyopia as a result of unilateral extensive myelinated retinal nerve fibers (MNFs) is illustrated. The electrophysiological readings revealed an abnormal pattern electroretinogram (PERG) but normal full-field electroretinogram readings in the affected eye. The visual-evoked potential was also undetectable in that eye. Our findings suggest that extensive MNFs can be associated with electrophysiological abnormalities, in particular the PERG, which can aid in diagnosing the cause of impaired vision when associated with amblyopia.

  4. Electrophysiological abnormalities associated with extensive myelinated retinal nerve fibers

    PubMed Central

    Tay, Su Ann; Sanjay, Srinivasan

    2012-01-01

    An observational case report of electrophysiological abnormalities in a patient with anisomyopic amblyopia as a result of unilateral extensive myelinated retinal nerve fibers (MNFs) is illustrated. The electrophysiological readings revealed an abnormal pattern electroretinogram (PERG) but normal full-field electroretinogram readings in the affected eye. The visual-evoked potential was also undetectable in that eye. Our findings suggest that extensive MNFs can be associated with electrophysiological abnormalities, in particular the PERG, which can aid in diagnosing the cause of impaired vision when associated with amblyopia. PMID:22824610

  5. Sensory experience modifies feature map relationships in visual cortex

    PubMed Central

    Cloherty, Shaun L; Hughes, Nicholas J; Hietanen, Markus A; Bhagavatula, Partha S

    2016-01-01

    The extent to which brain structure is influenced by sensory input during development is a critical but controversial question. A paradigmatic system for studying this is the mammalian visual cortex. Maps of orientation preference (OP) and ocular dominance (OD) in the primary visual cortex of ferrets, cats and monkeys can be individually changed by altered visual input. However, the spatial relationship between OP and OD maps has appeared immutable. Using a computational model we predicted that biasing the visual input to orthogonal orientation in the two eyes should cause a shift of OP pinwheels towards the border of OD columns. We then confirmed this prediction by rearing cats wearing orthogonally oriented cylindrical lenses over each eye. Thus, the spatial relationship between OP and OD maps can be modified by visual experience, revealing a previously unknown degree of brain plasticity in response to sensory input. DOI: http://dx.doi.org/10.7554/eLife.13911.001 PMID:27310531

  6. Video-Game Play Induces Plasticity in the Visual System of Adults with Amblyopia

    PubMed Central

    Li, Roger W.; Ngo, Charlie; Nguyen, Jennie; Levi, Dennis M.

    2011-01-01

    Abnormal visual experience during a sensitive period of development disrupts neuronal circuitry in the visual cortex and results in abnormal spatial vision or amblyopia. Here we examined whether playing video games can induce plasticity in the visual system of adults with amblyopia. Specifically 20 adults with amblyopia (age 15–61 y; visual acuity: 20/25–20/480, with no manifest ocular disease or nystagmus) were recruited and allocated into three intervention groups: action videogame group (n = 10), non-action videogame group (n = 3), and crossover control group (n = 7). Our experiments show that playing video games (both action and non-action games) for a short period of time (40–80 h, 2 h/d) using the amblyopic eye results in a substantial improvement in a wide range of fundamental visual functions, from low-level to high-level, including visual acuity (33%), positional acuity (16%), spatial attention (37%), and stereopsis (54%). Using a cross-over experimental design (first 20 h: occlusion therapy, and the next 40 h: videogame therapy), we can conclude that the improvement cannot be explained simply by eye patching alone. We quantified the limits and the time course of visual plasticity induced by video-game experience. The recovery in visual acuity that we observed is at least 5-fold faster than would be expected from occlusion therapy in childhood amblyopia. We used positional noise and modelling to reveal the neural mechanisms underlying the visual improvements in terms of decreased spatial distortion (7%) and increased processing efficiency (33%). Our study had several limitations: small sample size, lack of randomization, and differences in numbers between groups. A large-scale randomized clinical study is needed to confirm the therapeutic value of video-game treatment in clinical situations. Nonetheless, taken as a pilot study, this work suggests that video-game play may provide important principles for treating amblyopia, and perhaps

  7. Video-game play induces plasticity in the visual system of adults with amblyopia.

    PubMed

    Li, Roger W; Ngo, Charlie; Nguyen, Jennie; Levi, Dennis M

    2011-08-01

    Abnormal visual experience during a sensitive period of development disrupts neuronal circuitry in the visual cortex and results in abnormal spatial vision or amblyopia. Here we examined whether playing video games can induce plasticity in the visual system of adults with amblyopia. Specifically 20 adults with amblyopia (age 15-61 y; visual acuity: 20/25-20/480, with no manifest ocular disease or nystagmus) were recruited and allocated into three intervention groups: action videogame group (n = 10), non-action videogame group (n = 3), and crossover control group (n = 7). Our experiments show that playing video games (both action and non-action games) for a short period of time (40-80 h, 2 h/d) using the amblyopic eye results in a substantial improvement in a wide range of fundamental visual functions, from low-level to high-level, including visual acuity (33%), positional acuity (16%), spatial attention (37%), and stereopsis (54%). Using a cross-over experimental design (first 20 h: occlusion therapy, and the next 40 h: videogame therapy), we can conclude that the improvement cannot be explained simply by eye patching alone. We quantified the limits and the time course of visual plasticity induced by video-game experience. The recovery in visual acuity that we observed is at least 5-fold faster than would be expected from occlusion therapy in childhood amblyopia. We used positional noise and modelling to reveal the neural mechanisms underlying the visual improvements in terms of decreased spatial distortion (7%) and increased processing efficiency (33%). Our study had several limitations: small sample size, lack of randomization, and differences in numbers between groups. A large-scale randomized clinical study is needed to confirm the therapeutic value of video-game treatment in clinical situations. Nonetheless, taken as a pilot study, this work suggests that video-game play may provide important principles for treating amblyopia, and perhaps other

  8. Using Visual Literacy to Teach Science Academic Language: Experiences from Three Preservice Teachers

    ERIC Educational Resources Information Center

    Kelly-Jackson, Charlease; Delacruz, Stacy

    2014-01-01

    This original pedagogical study captured three preservice teachers' experiences using visual literacy strategies as an approach to teaching English language learners (ELLs) science academic language. The following research questions guided this study: (1) What are the experiences of preservice teachers' use of visual literacy to teach science…

  9. [Nursing Experience of Using Mirror Visual Feedback for a Schizophrenia Patient With Visual Hallucinations].

    PubMed

    Lan, Shu-Ling; Chen, Yu-Chi; Chang, Hsiu-Ju

    2018-06-01

    The aim of this paper was to describe the nursing application of mirror visual feedback in a patient suffering from long-term visual hallucinations. The intervention period was from May 15th to October 19th, 2015. Using the five facets of psychiatric nursing assessment, several health problems were observed, including disturbed sensory perceptions (prominent visual hallucinations) and poor self-care (e.g. limited abilities to self-bathe and put on clothing). Furthermore, "caregiver role strain" due to the related intense care burden was noted. After building up a therapeutic interpersonal relationship, the technique of brain plasticity and mirror visual feedback were performed using multiple nursing care methods in order to help the patient suppress her visual hallucinations by enhancing a different visual stimulus. We also taught her how to cope with visual hallucinations in a proper manner. The frequency and content of visual hallucinations were recorded to evaluate the effects of management. The therapeutic plan was formulated together with the patient in order to boost her self-confidence, and a behavior contract was implemented in order to improve her personal hygiene. In addition, psychoeducation on disease-related topics was provided to the patient's family, and they were encouraged to attend relevant therapeutic activities. As a result, her family became less passive and negative and more engaged in and positive about her future. The crisis of "caregiver role strain" was successfully resolved. The current experience is hoped to serve as a model for enhancing communication and cooperation between family and staff in similar medical settings.

  10. 'Visual’ parsing can be taught quickly without visual experience during critical periods

    PubMed Central

    Reich, Lior; Amedi, Amir

    2015-01-01

    Cases of invasive sight-restoration in congenital blind adults demonstrated that acquiring visual abilities is extremely challenging, presumably because visual-experience during critical-periods is crucial for learning visual-unique concepts (e.g. size constancy). Visual rehabilitation can also be achieved using sensory-substitution-devices (SSDs) which convey visual information non-invasively through sounds. We tested whether one critical concept – visual parsing, which is highly-impaired in sight-restored patients – can be learned using SSD. To this end, congenitally blind adults participated in a unique, relatively short (~70 hours), SSD-‘vision’ training. Following this, participants successfully parsed 2D and 3D visual objects. Control individuals naïve to SSDs demonstrated that while some aspects of parsing with SSD are intuitive, the blind’s success could not be attributed to auditory processing alone. Furthermore, we had a unique opportunity to compare the SSD-users’ abilities to those reported for sight-restored patients who performed similar tasks visually, and who had months of eyesight. Intriguingly, the SSD-users outperformed the patients on most criteria tested. These suggest that with adequate training and technologies, key high-order visual features can be quickly acquired in adulthood, and lack of visual-experience during critical-periods can be somewhat compensated for. Practically, these highlight the potential of SSDs as standalone-aids or combined with invasive restoration approaches. PMID:26482105

  11. Absence of visual experience modifies the neural basis of numerical thinking

    PubMed Central

    Kanjlia, Shipra; Lane, Connor; Feigenson, Lisa; Bedny, Marina

    2016-01-01

    In humans, the ability to reason about mathematical quantities depends on a frontoparietal network that includes the intraparietal sulcus (IPS). How do nature and nurture give rise to the neurobiology of numerical cognition? We asked how visual experience shapes the neural basis of numerical thinking by studying numerical cognition in congenitally blind individuals. Blind (n = 17) and blindfolded sighted (n = 19) participants solved math equations that varied in difficulty (e.g., 27 − 12 = x vs. 7 − 2 = x), and performed a control sentence comprehension task while undergoing fMRI. Whole-cortex analyses revealed that in both blind and sighted participants, the IPS and dorsolateral prefrontal cortices were more active during the math task than the language task, and activity in the IPS increased parametrically with equation difficulty. Thus, the classic frontoparietal number network is preserved in the total absence of visual experience. However, surprisingly, blind but not sighted individuals additionally recruited a subset of early visual areas during symbolic math calculation. The functional profile of these “visual” regions was identical to that of the IPS in blind but not sighted individuals. Furthermore, in blindness, number-responsive visual cortices exhibited increased functional connectivity with prefrontal and IPS regions that process numbers. We conclude that the frontoparietal number network develops independently of visual experience. In blindness, this number network colonizes parts of deafferented visual cortex. These results suggest that human cortex is highly functionally flexible early in life, and point to frontoparietal input as a mechanism of cross-modal plasticity in blindness. PMID:27638209

  12. Newborn chickens generate invariant object representations at the onset of visual object experience

    PubMed Central

    Wood, Justin N.

    2013-01-01

    To recognize objects quickly and accurately, mature visual systems build invariant object representations that generalize across a range of novel viewing conditions (e.g., changes in viewpoint). To date, however, the origins of this core cognitive ability have not yet been established. To examine how invariant object recognition develops in a newborn visual system, I raised chickens from birth for 2 weeks within controlled-rearing chambers. These chambers provided complete control over all visual object experiences. In the first week of life, subjects’ visual object experience was limited to a single virtual object rotating through a 60° viewpoint range. In the second week of life, I examined whether subjects could recognize that virtual object from novel viewpoints. Newborn chickens were able to generate viewpoint-invariant representations that supported object recognition across large, novel, and complex changes in the object’s appearance. Thus, newborn visual systems can begin building invariant object representations at the onset of visual object experience. These abstract representations can be generated from sparse data, in this case from a visual world containing a single virtual object seen from a limited range of viewpoints. This study shows that powerful, robust, and invariant object recognition machinery is an inherent feature of the newborn brain. PMID:23918372

  13. The onset of visual experience gates auditory cortex critical periods

    PubMed Central

    Mowery, Todd M.; Kotak, Vibhakar C.; Sanes, Dan H.

    2016-01-01

    Sensory systems influence one another during development and deprivation can lead to cross-modal plasticity. As auditory function begins before vision, we investigate the effect of manipulating visual experience during auditory cortex critical periods (CPs) by assessing the influence of early, normal and delayed eyelid opening on hearing loss-induced changes to membrane and inhibitory synaptic properties. Early eyelid opening closes the auditory cortex CPs precociously and dark rearing prevents this effect. In contrast, delayed eyelid opening extends the auditory cortex CPs by several additional days. The CP for recovery from hearing loss is also closed prematurely by early eyelid opening and extended by delayed eyelid opening. Furthermore, when coupled with transient hearing loss that animals normally fully recover from, very early visual experience leads to inhibitory deficits that persist into adulthood. Finally, we demonstrate a functional projection from the visual to auditory cortex that could mediate these effects. PMID:26786281

  14. Abnormal Fixational Eye Movements in Amblyopia.

    PubMed

    Shaikh, Aasef G; Otero-Millan, Jorge; Kumar, Priyanka; Ghasia, Fatema F

    2016-01-01

    Fixational saccades shift the foveal image to counteract visual fading related to neural adaptation. Drifts are slow eye movements between two adjacent fixational saccades. We quantified fixational saccades and asked whether their changes could be attributed to pathologic drifts seen in amblyopia, one of the most common causes of blindness in childhood. Thirty-six pediatric subjects with varying severity of amblyopia and eleven healthy age-matched controls held their gaze on a visual target. Eye movements were measured with high-resolution video-oculography during fellow eye-viewing and amblyopic eye-viewing conditions. Fixational saccades and drifts were analyzed in the amblyopic and fellow eye and compared with controls. We found an increase in the amplitude with decreased frequency of fixational saccades in children with amblyopia. These alterations in fixational eye movements correlated with the severity of their amblyopia. There was also an increase in eye position variance during drifts in amblyopes. There was no correlation between the eye position variance or the eye velocity during ocular drifts and the amplitude of subsequent fixational saccade. Our findings suggest that abnormalities in fixational saccades in amblyopia are independent of the ocular drift. This investigation of amblyopia in pediatric age group quantitatively characterizes the fixation instability. Impaired properties of fixational saccades could be the consequence of abnormal processing and reorganization of the visual system in amblyopia. Paucity in the visual feedback during amblyopic eye-viewing condition can attribute to the increased eye position variance and drift velocity.

  15. Visual evoked potentials in patients after methanol poisoning.

    PubMed

    Urban, Pavel; Zakharov, Sergey; Diblík, Pavel; Pelclová, Daniela; Ridzoň, Petr

    2016-01-01

    We report the results of the visual evoked potentials (VEP) examination in patients after severe poisoning by methanol. The group of 47 patients (38 males and 9 females) was assembled out of persons who survived an outbreak of poisoning by the methanol adulterated alcohol beverages, which happened in the Czech Republic in 2012-2013. The visual evoked potentials examination was performed using monocular checkerboard pattern-reversal stimulation. Two criteria of abnormality were chosen: missing evoked response, and wave P1 latency > 117 ms. Non-parametric statistical methods (median, range, and the median test) were used to analyze factors influencing the VEP abnormality. The visual evoked potential was abnormal in 20 patients (43%), 5 of them had normal visual acuity on the Snellen chart. The VEP abnormality did not correlate significantly with initial serum concentrations of methanol, formic acid or lactate; however, it showed statistically significant inverse relation to the initial serum pH: the subgroup with the abnormal VEP had significantly lower median pH in comparison with the subgroup with the normal VEP (7.16 vs. 7.34, p = 0.04). The abnormality was not related to chronic alcohol abuse. The visual evoked potentials examination appeared sensitive enough to detected even subclinical impairment of the optic system. Metabolic acidosis is likely to be the key factor related to the development of visual damage induced by methanol. The examination performed with a delay of 1-9 months after the poisoning documented the situation relatively early after the event. It is considered as a baseline for the planned long-term follow-up of the patients, which will make it possible to assess the dynamics of the observed changes, their reversibility, and the occurrence of potential late sequelae. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  16. MBARI CANON Experiment Visualization and Analysis

    NASA Astrophysics Data System (ADS)

    Fatland, R.; Oscar, N.; Ryan, J. P.; Bellingham, J. G.

    2013-12-01

    We describe the task of understanding a marine drift experiment conducted by MBARI in Fall 2012 ('CANON'). Datasets were aggregated from a drifting ADCP, from the MBARI Environmental Sample Processor, from Long Range Autonomous Underwater Vehicles (LRAUVs), from other in situ sensors, from NASA and NOAA remote sensing platforms, from moorings, from shipboard CTD casts and from post-experiment metagenomic analysis. We seek to combine existing approaches to data synthesis -- visual inspection, cross correlation and co.-- with three new ideas. This approach has the purpose of differentiating biological signals into three causal categories: Microcurrent advection, physical factors and microbe metabolism. Respective examples are aberrance from Lagrangian frame drift due to windage, changes in solar flux over several days, and microbial population responses to shifts in nitrate concentration. The three ideas we implemented are as follows: First, we advect LRAUV data to look for patterns in time series data for conserved quanitities such as salinity. We investigate whether such patterns can be used to support or undermine the premise of Lagrangian motion of the experiment ensemble. Second we built a set of configurable filters that enable us to visually isolate segments of data: By type, value, time, anomaly and location. Third we associated data hypotheses with a Bayesian inferrence engine for the purpose of model validation, again across sections taken from within the complete data complex. The end result is towards a free-form exploration of experimental data with low latency: from question to view, from hypothesis to test (albeit with considerable preparatory effort.) Preliminary results show the three causal categories shifting in relative influence.

  17. Serial and semantic encoding of lists of words in schizophrenia patients with visual hallucinations.

    PubMed

    Brébion, Gildas; Ohlsen, Ruth I; Pilowsky, Lyn S; David, Anthony S

    2011-03-30

    Previous research has suggested that visual hallucinations in schizophrenia are associated with abnormal salience of visual mental images. Since visual imagery is used as a mnemonic strategy to learn lists of words, increased visual imagery might impede the other commonly used strategies of serial and semantic encoding. We had previously published data on the serial and semantic strategies implemented by patients when learning lists of concrete words with different levels of semantic organisation (Brébion et al., 2004). In this paper we present a re-analysis of these data, aiming at investigating the associations between learning strategies and visual hallucinations. Results show that the patients with visual hallucinations presented less serial clustering in the non-organisable list than the other patients. In the semantically organisable list with typical instances, they presented both less serial and less semantic clustering than the other patients. Thus, patients with visual hallucinations demonstrate reduced use of serial and semantic encoding in the lists made up of fairly familiar concrete words, which enable the formation of mental images. Although these results are preliminary, we propose that this different processing of the lists stems from the abnormal salience of the mental images such patients experience from the word stimuli. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  18. How Can Visual Experience Be Depicted? A Study of Close-Up Double Vision

    ERIC Educational Resources Information Center

    Green, James; Pepperell, Robert

    2014-01-01

    The attempt to record visual experience has been of central importance to many artists throughout the history of art. Vision itself is made up of many processes, both psychological and physiological, and is still only partially understood. This paper presents research into an aspect of visual experience descried as "close-up double…

  19. The lived experience of visual creative expression for young adult cancer survivors.

    PubMed

    Green, A R; Young, R A

    2015-09-01

    Engaging in visual creative expression individually and in a therapeutic setting can be a beneficial experience for cancer survivors; however, most research in this field has been conducted with older adults. The current study aimed to address this gap by utilising van Manen's hermeneutic phenomenology to answer the following question: 'What is the lived experience and meaning of visual creative expression for young adult cancer survivors?' Seven young adults, diagnosed with cancer between the ages of 18 and 35, were interviewed about creative expression experiences, which they engaged in individually and/or in a therapeutic setting. Data analysis included a thematic reflection, guided existential reflection, and a process of writing and rewriting. Two superordinate themes were identified: increased self-understanding and a healing experience. Seven subthemes were also identified and included the following: being in the flow, allowing the body to express itself, renegotiating control, changing one's environment, being seen, respect for art as a separate entity and giving back. Findings suggest that visual creative expression can be a meaningful experience for young adult cancer survivors, and that this experience espouses both similarities and differences from experiences of older adult survivors. Recommendations are made for future research, in addition to implications for practitioners. © 2014 John Wiley & Sons Ltd.

  20. Role of the visual experience-dependent nascent proteome in neuronal plasticity

    PubMed Central

    Liu, Han-Hsuan; McClatchy, Daniel B; Schiapparelli, Lucio; Shen, Wanhua; Yates, John R

    2018-01-01

    Experience-dependent synaptic plasticity refines brain circuits during development. To identify novel protein synthesis-dependent mechanisms contributing to experience-dependent plasticity, we conducted a quantitative proteomic screen of the nascent proteome in response to visual experience in Xenopus optic tectum using bio-orthogonal metabolic labeling (BONCAT). We identified 83 differentially synthesized candidate plasticity proteins (CPPs). The CPPs form strongly interconnected networks and are annotated to a variety of biological functions, including RNA splicing, protein translation, and chromatin remodeling. Functional analysis of select CPPs revealed the requirement for eukaryotic initiation factor three subunit A (eIF3A), fused in sarcoma (FUS), and ribosomal protein s17 (RPS17) in experience-dependent structural plasticity in tectal neurons and behavioral plasticity in tadpoles. These results demonstrate that the nascent proteome is dynamic in response to visual experience and that de novo synthesis of machinery that regulates RNA splicing and protein translation is required for experience-dependent plasticity. PMID:29412139

  1. Complex patterns of abnormal heartbeats

    NASA Technical Reports Server (NTRS)

    Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

    2002-01-01

    Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical "heartprints" which reveal characteristic patterns in long clinical records encompassing approximately 10(5) heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

  2. Retinotopic maps and foveal suppression in the visual cortex of amblyopic adults

    PubMed Central

    Conner, Ian P; Odom, J Vernon; Schwartz, Terry L; Mendola, Janine D

    2007-01-01

    Amblyopia is a developmental visual disorder associated with loss of monocular acuity and sensitivity as well as profound alterations in binocular integration. Abnormal connections in visual cortex are known to underlie this loss, but the extent to which these abnormalities are regionally or retinotopically specific has not been fully determined. This functional magnetic resonance imaging (fMRI) study compared the retinotopic maps in visual cortex produced by each individual eye in 19 adults (7 esotropic strabismics, 6 anisometropes and 6 controls). In our standard viewing condition, the non-tested eye viewed a dichoptic homogeneous mid-level grey stimulus, thereby permitting some degree of binocular interaction. Regions-of-interest analysis was performed for extrafoveal V1, extrafoveal V2 and the foveal representation at the occipital pole. In general, the blood oxygenation level-dependent (BOLD) signal was reduced for the amblyopic eye. At the occipital pole, population receptive fields were shifted to represent more parafoveal locations for the amblyopic eye, compared with the fellow eye, in some subjects. Interestingly, occluding the fellow eye caused an expanded foveal representation for the amblyopic eye in one early–onset strabismic subject with binocular suppression, indicating real-time cortical remapping. In addition, a few subjects actually showed increased activity in parietal and temporal cortex when viewing with the amblyopic eye. We conclude that, even in a heterogeneous population, abnormal early visual experience commonly leads to regionally specific cortical adaptations. PMID:17627994

  3. Retinotopic maps and foveal suppression in the visual cortex of amblyopic adults.

    PubMed

    Conner, Ian P; Odom, J Vernon; Schwartz, Terry L; Mendola, Janine D

    2007-08-15

    Amblyopia is a developmental visual disorder associated with loss of monocular acuity and sensitivity as well as profound alterations in binocular integration. Abnormal connections in visual cortex are known to underlie this loss, but the extent to which these abnormalities are regionally or retinotopically specific has not been fully determined. This functional magnetic resonance imaging (fMRI) study compared the retinotopic maps in visual cortex produced by each individual eye in 19 adults (7 esotropic strabismics, 6 anisometropes and 6 controls). In our standard viewing condition, the non-tested eye viewed a dichoptic homogeneous mid-level grey stimulus, thereby permitting some degree of binocular interaction. Regions-of-interest analysis was performed for extrafoveal V1, extrafoveal V2 and the foveal representation at the occipital pole. In general, the blood oxygenation level-dependent (BOLD) signal was reduced for the amblyopic eye. At the occipital pole, population receptive fields were shifted to represent more parafoveal locations for the amblyopic eye, compared with the fellow eye, in some subjects. Interestingly, occluding the fellow eye caused an expanded foveal representation for the amblyopic eye in one early-onset strabismic subject with binocular suppression, indicating real-time cortical remapping. In addition, a few subjects actually showed increased activity in parietal and temporal cortex when viewing with the amblyopic eye. We conclude that, even in a heterogeneous population, abnormal early visual experience commonly leads to regionally specific cortical adaptations.

  4. Visual development in primates: Neural mechanisms and critical periods

    PubMed Central

    Kiorpes, Lynne

    2015-01-01

    Despite many decades of research into the development of visual cortex, it remains unclear what neural processes set limitations on the development of visual function and define its vulnerability to abnormal visual experience. This selected review examines the development of visual function and its neural correlates, and highlights the fact that in most cases receptive field properties of infant neurons are substantially more mature than infant visual function. One exception is temporal resolution, which can be accounted for by resolution of neurons at the level of the LGN. In terms of spatial vision, properties of single neurons alone are not sufficient to account for visual development. Different visual functions develop over different time courses. Their onset may be limited by the existence of neural response properties that support a given perceptual ability, but the subsequent time course of maturation to adult levels remains unexplained. Several examples are offered suggesting that taking account of weak signaling by infant neurons, correlated firing, and pooled responses of populations of neurons brings us closer to an understanding of the relationship between neural and behavioral development. PMID:25649764

  5. Visualization experiments on steam injection in Hele-Shaw cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kong, Xianli; Haghighi, M.; Yortsos, Y.C.

    1992-03-01

    Flow visualization experiments have been successfully employed in reservoir engineering research for many years. They involve 2-D geometries in transparent Hele-Shaw cells and glass micromodels. Although much work has been done on immiscible flows (drainage or imbibition), visualization of steamfloods, which constitute a major part of current EOR methods, has not been attempted to data. In this paper, we present experimental results on steam injection in a transparent, pyrex glass Hele-Shaw cell. Both synthetic (Dutrex 739) and natural heavy oils were used under a variety of conditions, including effects of gravity.

  6. Visual impairment in children with congenital Zika syndrome.

    PubMed

    Ventura, Liana O; Ventura, Camila V; Lawrence, Linda; van der Linden, Vanessa; van der Linden, Ana; Gois, Adriana L; Cavalcanti, Milena M; Barros, Eveline A; Dias, Natalia C; Berrocal, Audina M; Miller, Marilyn T

    2017-08-01

    To describe the visual impairment associated with ocular and neurological abnormalities in a cohort of children with congenital Zika syndrome (CZS). This cross-sectional study included infants with microcephaly born in Pernambuco, Brazil, from May to December 2015. Immunoglobulin M antibody capture enzyme-linked immunosorbent assay for the Zika virus on the cerebrospinal fluid samples was positive for all infants. Clinical evaluation consisted of comprehensive ophthalmologic examination including visual acuity, visual function assessment, visual developmental milestone, neurologic examination, and neuroimaging. A total of 32 infants (18 males [56%]) were included. Mean age at examination was 5.7 ± 0.9 months (range, 4-7 months). Visual function and visual developmental milestone could not be tested in 1 child (3%). Visual impairment was detected in 32 infants (100%). Retinal and/or optic nerve findings were observed in 14 patients (44%). There was no statistical difference between the patients with ocular findings and those without (P = 0.180). All patients (100%) demonstrated neurological and neuroimaging abnormalities; 3 (9%) presented with late-onset of microcephaly. Children with CZS demonstrated visual impairment regardless of retina and/or optic nerve abnormalities. This finding suggests that cortical/cerebral visual impairment may be the most common cause of blindness identified in children with CZS. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  7. Abnormal Fixational Eye Movements in Amblyopia

    PubMed Central

    Shaikh, Aasef G.; Otero-Millan, Jorge; Kumar, Priyanka; Ghasia, Fatema F.

    2016-01-01

    Purpose Fixational saccades shift the foveal image to counteract visual fading related to neural adaptation. Drifts are slow eye movements between two adjacent fixational saccades. We quantified fixational saccades and asked whether their changes could be attributed to pathologic drifts seen in amblyopia, one of the most common causes of blindness in childhood. Methods Thirty-six pediatric subjects with varying severity of amblyopia and eleven healthy age-matched controls held their gaze on a visual target. Eye movements were measured with high-resolution video-oculography during fellow eye-viewing and amblyopic eye-viewing conditions. Fixational saccades and drifts were analyzed in the amblyopic and fellow eye and compared with controls. Results We found an increase in the amplitude with decreased frequency of fixational saccades in children with amblyopia. These alterations in fixational eye movements correlated with the severity of their amblyopia. There was also an increase in eye position variance during drifts in amblyopes. There was no correlation between the eye position variance or the eye velocity during ocular drifts and the amplitude of subsequent fixational saccade. Our findings suggest that abnormalities in fixational saccades in amblyopia are independent of the ocular drift. Discussion This investigation of amblyopia in pediatric age group quantitatively characterizes the fixation instability. Impaired properties of fixational saccades could be the consequence of abnormal processing and reorganization of the visual system in amblyopia. Paucity in the visual feedback during amblyopic eye-viewing condition can attribute to the increased eye position variance and drift velocity. PMID:26930079

  8. ACR appropriateness criteria(®) on abnormal vaginal bleeding.

    PubMed

    Bennett, Genevieve L; Andreotti, Rochelle F; Lee, Susanna I; Dejesus Allison, Sandra O; Brown, Douglas L; Dubinsky, Theodore; Glanc, Phyllis; Mitchell, Donald G; Podrasky, Ann E; Shipp, Thomas D; Siegel, Cary Lynn; Wong-You-Cheong, Jade J; Zelop, Carolyn M

    2011-07-01

    In evaluating a woman with abnormal vaginal bleeding, imaging cannot replace definitive histologic diagnosis but often plays an important role in screening, characterization of structural abnormalities, and directing appropriate patient care. Transvaginal ultrasound (TVUS) is generally the initial imaging modality of choice, with endometrial thickness a well-established predictor of endometrial disease in postmenopausal women. Endometrial thickness measurements of ≤5 mm and ≤4 mm have been advocated as appropriate upper threshold values to reasonably exclude endometrial carcinoma in postmenopausal women with vaginal bleeding; however, the best upper threshold endometrial thickness in the asymptomatic postmenopausal patient remains a subject of debate. Endometrial thickness in a premenopausal patient is a less reliable indicator of endometrial pathology since this may vary widely depending on the phase of menstrual cycle, and an upper threshold value for normal has not been well-established. Transabdominal ultrasound is generally an adjunct to TVUS and is most helpful when TVUS is not feasible or there is poor visualization of the endometrium. Hysterosonography may also allow for better delineation of both the endometrium and focal abnormalities in the endometrial cavity, leading to hysteroscopically directed biopsy or resection. Color and pulsed Doppler may provide additional characterization of a focal endometrial abnormality by demonstrating vascularity. MRI may also serve as an important problem-solving tool if the endometrium cannot be visualized on TVUS and hysterosonography is not possible, as well as for pretreatment planning of patients with suspected endometrial carcinoma. CT is generally not warranted for the evaluation of patients with abnormal bleeding, and an abnormal endometrium incidentally detected on CT should be further evaluated with TVUS. Copyright © 2011 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  9. Abnormal Visual Motion Processing is not a Cause of Dyslexia

    PubMed Central

    Olulade, Olumide A.; Napoliello, Eileen M.; Eden, Guinevere F.

    2013-01-01

    SUMMARY Developmental dyslexia is a reading disorder, yet deficits also manifest in the magnocellular-dominated dorsal visual system. Uncertainty about whether visual deficits are causal or consequential to reading disability encumbers accurate identification and appropriate treatment of this common learning disability. Using fMRI, we demonstrate in typical readers a relationship between reading ability and activity in area V5/MT during visual motion processing and, as expected, also found lower V5/MT activity for dyslexic children compared to age-matched controls. However, when dyslexics were matched to younger controls on reading ability, no differences emerged, suggesting that weakness in V5/MT may not be causal to dyslexia. To further test for causality, dyslexics underwent a phonological-based reading intervention. Surprisingly, V5/MT activity increased along with intervention-driven reading gains, demonstrating that activity here is mobilized through reading. Our results provide strong evidence that visual magnocellular dysfunction is not causal to dyslexia, but may instead be consequential to impoverished reading. PMID:23746630

  10. Diagnosing cerebral visual impairment in children with good visual acuity.

    PubMed

    van Genderen, Maria; Dekker, Marjoke; Pilon, Florine; Bals, Irmgard

    2012-06-01

    To identify elements that could facilitate the diagnosis of cerebral visual impairment (CVI) in children with good visual acuity in the general ophthalmic clinic. We retrospectively investigated the clinical characteristics of 30 children with good visual acuity and CVI and compared them with those of 23 children who were referred with a suspicion of CVI, but proved to have a different diagnosis. Clinical characteristics included medical history, MRI findings, visual acuity, crowding ratio (CR), visual field assessment, and the results of ophthalmologic and orthoptic examination. We also evaluated the additional value of a short CVI questionnaire. Eighty-three percent of the children with an abnormal medical history (mainly prematurity and perinatal hypoxia) had CVI, in contrast with none of the children with a normal medical history. Cerebral palsy, visual field defects, and partial optic atrophy only occurred in the CVI group. 41% of the children with CVI had a CR ≥2.0, which may be related to dorsal stream dysfunction. All children with CVI, but also 91% of the children without CVI gave ≥3 affirmative answers on the CVI questionnaire. An abnormal pre- or perinatal medical history is the most important risk factor for CVI in children, and therefore in deciding which children should be referred for further multidisciplinary assessment. Additional symptoms of cerebral damage, i.e., cerebral palsy, visual field defects, partial optic atrophy, and a CR ≥2 may support the diagnosis. CVI questionnaires should not be used for screening purposes as they yield too many false positives.

  11. Recent Visual Experience Shapes Visual Processing in Rats through Stimulus-Specific Adaptation and Response Enhancement.

    PubMed

    Vinken, Kasper; Vogels, Rufin; Op de Beeck, Hans

    2017-03-20

    From an ecological point of view, it is generally suggested that the main goal of vision in rats and mice is navigation and (aerial) predator evasion [1-3]. The latter requires fast and accurate detection of a change in the visual environment. An outstanding question is whether there are mechanisms in the rodent visual system that would support and facilitate visual change detection. An experimental protocol frequently used to investigate change detection in humans is the oddball paradigm, in which a rare, unexpected stimulus is presented in a train of stimulus repetitions [4]. A popular "predictive coding" theory of cortical responses states that neural responses should decrease for expected sensory input and increase for unexpected input [5, 6]. Despite evidence for response suppression and enhancement in noninvasive scalp recordings in humans with this paradigm [7, 8], it has proven challenging to observe both phenomena in invasive action potential recordings in other animals [9-11]. During a visual oddball experiment, we recorded multi-unit spiking activity in rat primary visual cortex (V1) and latero-intermediate area (LI), which is a higher area of the rodent ventral visual stream. In rat V1, there was only evidence for response suppression related to stimulus-specific adaptation, and not for response enhancement. However, higher up in area LI, spiking activity showed clear surprise-based response enhancement in addition to stimulus-specific adaptation. These results show that neural responses along the rat ventral visual stream become increasingly sensitive to changes in the visual environment, suggesting a system specialized in the detection of unexpected events. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Neuron analysis of visual perception

    NASA Technical Reports Server (NTRS)

    Chow, K. L.

    1980-01-01

    The receptive fields of single cells in the visual system of cat and squirrel monkey were studied investigating the vestibular input affecting the cells, and the cell's responses during visual discrimination learning process. The receptive field characteristics of the rabbit visual system, its normal development, its abnormal development following visual deprivation, and on the structural and functional re-organization of the visual system following neo-natal and prenatal surgery were also studied. The results of each individual part of each investigation are detailed.

  13. Building effective learning experiences around visualizations: NASA Eyes on the Solar System and Infiniscope

    NASA Astrophysics Data System (ADS)

    Tamer, A. J. J.; Anbar, A. D.; Elkins-Tanton, L. T.; Klug Boonstra, S.; Mead, C.; Swann, J. L.; Hunsley, D.

    2017-12-01

    Advances in scientific visualization and public access to data have transformed science outreach and communication, but have yet to realize their potential impacts in the realm of education. Computer-based learning is a clear bridge between visualization and education, but creating high-quality learning experiences that leverage existing visualizations requires close partnerships among scientists, technologists, and educators. The Infiniscope project is working to foster such partnerships in order to produce exploration-driven learning experiences around NASA SMD data and images, leveraging the principles of ETX (Education Through eXploration). The visualizations inspire curiosity, while the learning design promotes improved reasoning skills and increases understanding of space science concepts. Infiniscope includes both a web portal to host these digital learning experiences, as well as a teaching network of educators using and modifying these experiences. Our initial efforts to enable student discovery through active exploration of the concepts associated with Small Worlds, Kepler's Laws, and Exoplanets led us to develop our own visualizations at Arizona State University. Other projects focused on Astrobiology and Mars geology led us to incorporate an immersive Virtual Field Trip platform into the Infiniscope portal in support of virtual exploration of scientifically significant locations. Looking to apply ETX design practices with other visualizations, our team at Arizona State partnered with the Jet Propulsion Lab to integrate the web-based version of NASA Eyes on the Eclipse within Smart Sparrow's digital learning platform in a proof-of-concept focused on the 2017 Eclipse. This goes a step beyond the standard features of "Eyes" by wrapping guided exploration, focused on a specific learning goal into standards-aligned lesson built around the visualization, as well as its distribution through Infiniscope and it's digital teaching network. Experience from this

  14. Video game experience and its influence on visual attention parameters: an investigation using the framework of the Theory of Visual Attention (TVA).

    PubMed

    Schubert, Torsten; Finke, Kathrin; Redel, Petra; Kluckow, Steffen; Müller, Hermann; Strobach, Tilo

    2015-05-01

    Experts with video game experience, in contrast to non-experienced persons, are superior in multiple domains of visual attention. However, it is an open question which basic aspects of attention underlie this superiority. We approached this question using the framework of Theory of Visual Attention (TVA) with tools that allowed us to assess various parameters that are related to different visual attention aspects (e.g., perception threshold, processing speed, visual short-term memory storage capacity, top-down control, spatial distribution of attention) and that are measurable on the same experimental basis. In Experiment 1, we found advantages of video game experts in perception threshold and visual processing speed; the latter being restricted to the lower positions of the used computer display. The observed advantages were not significantly moderated by general person-related characteristics such as personality traits, sensation seeking, intelligence, social anxiety, or health status. Experiment 2 tested a potential causal link between the expert advantages and video game practice with an intervention protocol. It found no effects of action video gaming on perception threshold, visual short-term memory storage capacity, iconic memory storage, top-down control, and spatial distribution of attention after 15 days of training. However, observations of a selected improvement of processing speed at the lower positions of the computer screen after video game training and of retest effects are suggestive for limited possibilities to improve basic aspects of visual attention (TVA) with practice. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. JoVE: the Journal of Visualized Experiments.

    PubMed

    Vardell, Emily

    2015-01-01

    The Journal of Visualized Experiments (JoVE) is the world's first scientific video journal and is designed to communicate research and scientific methods in an innovative, intuitive way. JoVE includes a wide range of biomedical videos, from biology to immunology and bioengineering to clinical and translation medicine. This column describes the browsing and searching capabilities of JoVE, as well as its additional features (including the JoVE Scientific Education Database designed for students in scientific fields).

  16. Experiences of Visually Impaired Students in Community College Math Courses

    NASA Astrophysics Data System (ADS)

    Swan, S. Tomeka

    Blind and visually impaired students who attend community colleges face challenges in learning mathematics (Forrest, 2010). Scoy, McLaughlin, Walls, and Zuppuhaur (2006) claim these students are at a disadvantage in studying mathematics due to the visual and interactive nature of the subject, and by the way mathematics is taught. In this qualitative study six blind and visually impaired students attended three community colleges in one Mid-Atlantic state. They shared their experiences inside the mathematics classroom. Five of the students were enrolled in developmental level math, and one student was enrolled in college level math. The conceptual framework used to explore how blind and visually impaired students persist and succeed in math courses was Piaget's theory on constructivism. The data from this qualitative study was obtained through personal interviews. Based on the findings of this study, blind and visually impaired students need the following accommodations in order to succeed in community college math courses: Accommodating instructors who help to keep blind and visually impaired students motivated and facilitate their academic progress towards math completion, tutorial support, assistive technology, and a positive and inclusive learning environment.

  17. Should we add visual acuity ratios to referral criteria for potential cerebral visual impairment?

    PubMed

    van der Zee, Ymie J; Stiers, Peter; Evenhuis, Heleen M

    To determine whether the assessment of visual acuity ratios might improve the referral of children with (sub)normal visual acuity but at risk of cerebral visual impairment. In an exploratory study, we assessed visual acuity, crowding ratio and the ratios between grating acuity (Teller Acuity Cards-II) and optotype acuity (Cambridge Crowding Cards) in 60 typically developing school children (mean age 5y8m±1y1m), 21 children with ocular abnormalities only (5y7m±1y9m) and 26 children with (suspected) brain damage (5y7m±1y11m). Sensitivities and specificities were calculated for targets and controls from the perspective of different groups of diagnosticians: youth health care professionals (target: children with any visual abnormalities), ophthalmologists and low vision experts (target: children at risk of cerebral visual impairment). For youth health care professionals subnormal visual acuity had the best sensitivity (76%) and specificity (70%). For ophthalmologists and low vision experts the crowding ratio had the best sensitivity (67%) and specificity (79 and 86%). Youth health care professionals best continue applying subnormal visual acuity for screening, whereas ophthalmologists and low vision experts best add the crowding ratio to their routine diagnostics, to distinguish children at risk of visual impairment in the context of brain damage from children with ocular pathology only. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  18. Three-dimensional brain growth abnormalities in childhood-onset schizophrenia visualized by using tensor-based morphometry.

    PubMed

    Gogtay, Nitin; Lu, Allen; Leow, Alex D; Klunder, Andrea D; Lee, Agatha D; Chavez, Alex; Greenstein, Deanna; Giedd, Jay N; Toga, Arthur W; Rapoport, Judith L; Thompson, Paul M

    2008-10-14

    Earlier studies revealed progressive cortical gray matter (GM) loss in childhood-onset schizophrenia (COS) across both lateral and medial surfaces of the developing brain. Here, we use tensor-based morphometry to visualize white matter (WM) growth abnormalities in COS throughout the brain. Using high-dimensional elastic image registration, we compared 3D maps of local WM growth rates in COS patients and healthy children over a 5-year period, based on analyzing longitudinal brain MRIs from 12 COS patients and 12 healthy controls matched for age, gender, and scan interval. COS patients showed up to 2.2% slower growth rates per year than healthy controls in WM (P = 0.02, all P values corrected). The greatest differences were in the right hemisphere (P = 0.006). This asymmetry was attributable to a right slower than left hemisphere growth rate mapped in COS patients (P = 0.037) but not in healthy controls. WM growth rates reached 2.6% per year in healthy controls (P = 0.0002). COS patients showed only a 1.3% per year trend for growth in the left hemisphere (P = 0.066). In COS, WM growth rates were associated with improvement in the Children's Global Assessment Scale (R = 0.64, P = 0.029). Growth rates were reduced throughout the brain in COS, but this process appeared to progress in a front-to-back (frontal-parietal) fashion, and this effect was not attributable to lower IQ. Growth rates were correlated with functional prognosis and were visualized as detailed 3D maps. Finally, these findings also confirm that the progressive GM deficits seen in schizophrenia are not the result of WM overgrowth.

  19. Experiences of Individuals With Visual Impairments in Integrated Physical Education: A Retrospective Study.

    PubMed

    Haegele, Justin A; Zhu, Xihe

    2017-12-01

    The purpose of this retrospective study was to examine the experiences of adults with visual impairments during school-based integrated physical education (PE). An interpretative phenomenological analysis (IPA) research approach was used and 16 adults (ages 21-48 years; 10 women, 6 men) with visual impairments acted as participants for this study. The primary sources of data were semistructured audiotaped telephone interviews and reflective field notes, which were recorded during and immediately following each interview. Thematic development was undertaken utilizing a 3-step analytical process guided by IPA. Based on the data analysis, 3 interrelated themes emerged from the participant transcripts: (a) feelings about "being put to the side," frustration and inadequacy; (b) "She is blind, she can't do it," debilitating feelings from physical educators' attitudes; and (c) "not self-esteem raising," feelings about peer interactions. The 1st theme described the participants' experiences and ascribed meaning to exclusionary practices. The 2nd theme described the participants' frustration over being treated differently by their PE teachers because of their visual impairments. Lastly, "not self-esteem raising," feelings about peer interactions demonstrated how participants felt about issues regarding challenging social situations with peers in PE. Utilizing an IPA approach, the researchers uncovered 3 interrelated themes that depicted central feelings, experiences, and reflections, which informed the meaning of the participants' PE experiences. The emerged themes provide unique insight into the embodied experiences of those with visual impairments in PE and fill a previous gap in the extant literature.

  20. Comparison of multifocal visual evoked potential, standard automated perimetry and optical coherence tomography in assessing visual pathway in multiple sclerosis patients

    PubMed Central

    Laron, Michal; Cheng, Han; Zhang, Bin; Schiffman, Jade S.; Tang, Rosa A.; Frishman, Laura J.

    2010-01-01

    Background Multifocal visual evoked potentials (mfVEP) measure local response amplitude and latency in the field of vision Objective To compare the sensitivity of mfVEP, Humphrey visual field (HVF) and optical coherence tomography (OCT) in detecting visual abnormality in multiple sclerosis (MS) patients. Methods MfVEP, HVF, and OCT (retinal nerve fiber layer [RNFL]) were performed in 47 MS-ON eyes (last optic neuritis (ON) attack ≥ 6 months prior) and 65 MS-no-ON eyes without ON history. Criteria to define an eye as abnormal were: mfVEP 1) amplitude/latency: either amplitude or latency probability plots meeting cluster criteria with 95% specificity 2) amplitude or latency alone (specificity: 97% and 98%, respectively); HVF and OCT, mean deviation and RNFL thickness meeting p < 0.05, respectively. Results MfVEP (amplitude/latency) identified more abnormality in MS-ON eyes (89%) than HVF (72%), OCT (62%), mfVEP amplitude (66%) or latency (67%) alone. 18% of MS-no-ON eyes were abnormal for both mfVEP (amplitude/latency) and HVF compared to 8% with OCT. Agreement between tests ranged from 60% to 79%. MfVEP (amplitude/latency) categorized an additional 15% of MS-ON eyes as abnormal compared to HVF and OCT combined. Conclusions MfVEP, which detects both demyelination (increased latency) and neural degeneration (reduced amplitude) revealed more abnormality than HVF or OCT in MS patients. PMID:20207786

  1. Visual-Spatial Orienting in Autism.

    ERIC Educational Resources Information Center

    Wainwright, J. Ann; Bryson, Susan E.

    1996-01-01

    Visual-spatial orienting in 10 high-functioning adults with autism was examined. Compared to controls, subjects responded faster to central than to lateral stimuli, and showed a left visual field advantage for stimulus detection only when laterally presented. Abnormalities in attention shifting and coordination of attentional and motor systems are…

  2. In-Situ Visualization Experiments with ParaView Cinema in RAGE

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kares, Robert John

    2015-10-15

    A previous paper described some numerical experiments performed using the ParaView/Catalyst in-situ visualization infrastructure deployed in the Los Alamos RAGE radiation-hydrodynamics code to produce images from a running large scale 3D ICF simulation. One challenge of the in-situ approach apparent in these experiments was the difficulty of choosing parameters likes isosurface values for the visualizations to be produced from the running simulation without the benefit of prior knowledge of the simulation results and the resultant cost of recomputing in-situ generated images when parameters are chosen suboptimally. A proposed method of addressing this difficulty is to simply render multiple images atmore » runtime with a range of possible parameter values to produce a large database of images and to provide the user with a tool for managing the resulting database of imagery. Recently, ParaView/Catalyst has been extended to include such a capability via the so-called Cinema framework. Here I describe some initial experiments with the first delivery of Cinema and make some recommendations for future extensions of Cinema’s capabilities.« less

  3. When viewing natural scenes, do abnormal colors impact on spatial or temporal parameters of eye movements?

    PubMed

    Ho-Phuoc, Tien; Guyader, Nathalie; Landragin, Frédéric; Guérin-Dugué, Anne

    2012-02-03

    Since Treisman's theory, it has been generally accepted that color is an elementary feature that guides eye movements when looking at natural scenes. Hence, most computational models of visual attention predict eye movements using color as an important visual feature. In this paper, using experimental data, we show that color does not affect where observers look when viewing natural scene images. Neither colors nor abnormal colors modify observers' fixation locations when compared to the same scenes in grayscale. In the same way, we did not find any significant difference between the scanpaths under grayscale, color, or abnormal color viewing conditions. However, we observed a decrease in fixation duration for color and abnormal color, and this was particularly true at the beginning of scene exploration. Finally, we found that abnormal color modifies saccade amplitude distribution.

  4. Women’s Experiences of Abnormal Cervical Cytology: Illness Representations, Care Processes, and Outcomes

    PubMed Central

    Karasz, Alison; McKee, M. Diane; Roybal, Krista

    2003-01-01

    BACKGROUND We wanted to explore the conceptual representations of illness and experiences with care among women who have learned of an abnormal Papanicolaou (Pap) smear result. METHODS The study took place in 2 primary care, family practice clinics serving low-income, multiethnic patients in the Bronx, New York City. We conducted qualitative, semistructured telephone interviews with 17 patients who had recently learned of abnormal findings on a Pap smear. After a preliminary coding phase, the investigators identified 2 important outcomes: distress and dissatisfaction with care, and factors affecting these outcomes. A model was developed on a subset of the data, which was then tested on each transcript with an explicit search for disconfirming cases. A revised coding scheme conforming to the dimensions of the model was used to recode transcripts. RESULTS Women reported complex, syncretic models of illness that included both biomedical and folk elements. Many concerns, especially nonbiomedical concerns, were not addressed in interactions with physicians. An important source of both distress and dissatisfaction with care was the women’s lack of understanding of the inherent ambiguity of Pap smear results. When perceived care needs, which included emotional support as well as information, were not met, distress and dissatisfaction were greatly increased. CONCLUSION In this study, patients’ illness models and expectations of care were not routinely addressed in their conversations with physicians about abnormal Pap smear results. When physicians can take the time to review patients’ illness models carefully, distress and dissatisfaction with care can be reduced considerably. PMID:15055408

  5. Abnormal white matter tractography of visual pathways detected by high-angular-resolution diffusion imaging (HARDI) corresponds to visual dysfunction in cortical/cerebral visual impairment

    PubMed Central

    Bauer, Corinna M.; Heidary, Gena; Koo, Bang-Bon; Killiany, Ronald J.; Bex, Peter; Merabet, Lotfi B.

    2014-01-01

    Cortical (cerebral) visual impairment (CVI) is characterized by visual dysfunction associated with damage to the optic radiations and/or visual cortex. Typically it results from pre- or perinatal hypoxic damage to postchiasmal visual structures and pathways. The neuroanatomical basis of this condition remains poorly understood, particularly with regard to how the resulting maldevelopment of visual processing pathways relates to observations in the clinical setting. We report our investigation of 2 young adults diagnosed with CVI and visual dysfunction characterized by difficulties related to visually guided attention and visuospatial processing. Using high-angular-resolution diffusion imaging (HARDI), we characterized and compared their individual white matter projections of the extrageniculo-striate visual system with a normal-sighted control. Compared to a sighted control, both CVI cases revealed a striking reduction in association fibers, including the inferior frontal-occipital fasciculus as well as superior and inferior longitudinal fasciculi. This reduction in fibers associated with the major pathways implicated in visual processing may provide a neuroanatomical basis for the visual dysfunctions observed in these patients. PMID:25087644

  6. Macular photostress and visual experience between microscope and intracameral illumination during cataract surgery.

    PubMed

    Seo, Hyejin; Nam, Dong Heun; Lee, Jong Yeon; Park, Su Jin; Kim, Yu Jeong; Kim, Seong-Woo; Chung, Tae-Young; Inoue, Makoto; Kim, Terry

    2018-02-01

    To evaluate macular photostress and visual experience between coaxial microscope illumination versus oblique intracameral illumination during cataract surgery. Gachon University Gil Hospital, Incheon, South Korea. Prospective case series. Consecutive patients who had cataract surgery using microscope illumination and intracameral illumination were included. The patients were asked to complete a questionnaire (seeing strong lights, feeling photophobia, feeling startled (fright) when seeing lights, seeing any colors, seeing any instruments or surgical procedures, and estimating intraoperative visual function) designed to describe their cataract surgery experience. The images projected on the retina of the model eye (rear view) with artificial opaque fragments in the anterior chamber during simulating cataract surgery were compared between the 2 illumination types. Sixty patients completed the questionnaire. Scores for strong lights, photophobia, fright, and color perception were significantly higher with microscope illumination than with intracameral illumination (all P < .001). More patients preferred the intracameral illumination (45 [75.0%]) to the microscope illumination (13 [21.7%]). In the rear-view images created in a model eye, only the bright microscope light in the center was seen without any lens image in the microscope illumination. However, in the intracameral illumination, the less bright light from the light pipe in the periphery and the lens fragments were seen more clearly. In a view of the patients' visual experience, oblique intracameral illumination caused less subjective photostress and was preferred over coaxial microscope illumination. Objective findings from the model-eye experiment correlated to the result of visual experience. Copyright © 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  7. Conversational Pedagogy: Exploring Interactions between a Teaching Artist and Young Learners during Visual Arts Experiences

    ERIC Educational Resources Information Center

    Eckhoff, Angela

    2013-01-01

    In many early childhood classrooms, visual arts experiences occur around a communal arts table. A shared workspace allows for spontaneous conversation and exploration of the art-making process of peers and teachers. In this setting, conversation can play an important role in visual arts experiences as children explore new media, skills, and ideas.…

  8. The role of visual deprivation and experience on the performance of sensory substitution devices.

    PubMed

    Stronks, H Christiaan; Nau, Amy C; Ibbotson, Michael R; Barnes, Nick

    2015-10-22

    It is commonly accepted that the blind can partially compensate for their loss of vision by developing enhanced abilities with their remaining senses. This visual compensation may be related to the fact that blind people rely on their other senses in everyday life. Many studies have indeed shown that experience plays an important role in visual compensation. Numerous neuroimaging studies have shown that the visual cortices of the blind are recruited by other functional brain areas and can become responsive to tactile or auditory input instead. These cross-modal plastic changes are more pronounced in the early blind compared to late blind individuals. The functional consequences of cross-modal plasticity on visual compensation in the blind are debated, as are the influences of various etiologies of vision loss (i.e., blindness acquired early or late in life). Distinguishing between the influences of experience and visual deprivation on compensation is especially relevant for rehabilitation of the blind with sensory substitution devices. The BrainPort artificial vision device and The vOICe are assistive devices for the blind that redirect visual information to another intact sensory system. Establishing how experience and different etiologies of vision loss affect the performance of these devices may help to improve existing rehabilitation strategies, formulate effective selection criteria and develop prognostic measures. In this review we will discuss studies that investigated the influence of training and visual deprivation on the performance of various sensory substitution approaches. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Asymmetric Dichoptic Masking in Visual Cortex of Amblyopic Macaque Monkeys

    PubMed Central

    Shooner, Christopher; Hallum, Luke E.; García-Marín, Virginia; Kiorpes, Lynne

    2017-01-01

    In amblyopia, abnormal visual experience leads to an extreme form of eye dominance, in which vision through the nondominant eye is degraded. A key aspect of this disorder is perceptual suppression: the image seen by the stronger eye often dominates during binocular viewing, blocking the image of the weaker eye from reaching awareness. Interocular suppression is the focus of ongoing work aimed at understanding and treating amblyopia, yet its physiological basis remains unknown. We measured binocular interactions in visual cortex of anesthetized amblyopic monkeys (female Macaca nemestrina), using 96-channel “Utah” arrays to record from populations of neurons in V1 and V2. In an experiment reported recently (Hallum et al., 2017), we found that reduced excitatory input from the amblyopic eye (AE) revealed a form of balanced binocular suppression that is unaltered in amblyopia. Here, we report on the modulation of the gain of excitatory signals from the AE by signals from its dominant fellow eye (FE). Using a dichoptic masking technique, we found that AE responses to grating stimuli were attenuated by the presentation of a noise mask to the FE, as in a normal control animal. Responses to FE stimuli, by contrast, could not be masked from the AE. We conclude that a weakened ability of the amblyopic eye to modulate cortical response gain creates an imbalance of suppression that favors the dominant eye. SIGNIFICANCE STATEMENT In amblyopia, vision in one eye is impaired as a result of abnormal early visual experience. Behavioral observations in humans with amblyopia suggest that much of their visual loss is due to active suppression of their amblyopic eye. Here we describe experiments in which we studied binocular interactions in macaques with experimentally induced amblyopia. In normal monkeys, the gain of neuronal response to stimulation of one eye is modulated by contrast in the other eye, but in monkeys with amblyopia the balance of gain modulation is altered so that

  10. Asymmetric Dichoptic Masking in Visual Cortex of Amblyopic Macaque Monkeys.

    PubMed

    Shooner, Christopher; Hallum, Luke E; Kumbhani, Romesh D; García-Marín, Virginia; Kelly, Jenna G; Majaj, Najib J; Movshon, J Anthony; Kiorpes, Lynne

    2017-09-06

    In amblyopia, abnormal visual experience leads to an extreme form of eye dominance, in which vision through the nondominant eye is degraded. A key aspect of this disorder is perceptual suppression: the image seen by the stronger eye often dominates during binocular viewing, blocking the image of the weaker eye from reaching awareness. Interocular suppression is the focus of ongoing work aimed at understanding and treating amblyopia, yet its physiological basis remains unknown. We measured binocular interactions in visual cortex of anesthetized amblyopic monkeys (female Macaca nemestrina ), using 96-channel "Utah" arrays to record from populations of neurons in V1 and V2. In an experiment reported recently (Hallum et al., 2017), we found that reduced excitatory input from the amblyopic eye (AE) revealed a form of balanced binocular suppression that is unaltered in amblyopia. Here, we report on the modulation of the gain of excitatory signals from the AE by signals from its dominant fellow eye (FE). Using a dichoptic masking technique, we found that AE responses to grating stimuli were attenuated by the presentation of a noise mask to the FE, as in a normal control animal. Responses to FE stimuli, by contrast, could not be masked from the AE. We conclude that a weakened ability of the amblyopic eye to modulate cortical response gain creates an imbalance of suppression that favors the dominant eye. SIGNIFICANCE STATEMENT In amblyopia, vision in one eye is impaired as a result of abnormal early visual experience. Behavioral observations in humans with amblyopia suggest that much of their visual loss is due to active suppression of their amblyopic eye. Here we describe experiments in which we studied binocular interactions in macaques with experimentally induced amblyopia. In normal monkeys, the gain of neuronal response to stimulation of one eye is modulated by contrast in the other eye, but in monkeys with amblyopia the balance of gain modulation is altered so that

  11. A systematic review of visual processing and associated treatments in body dysmorphic disorder.

    PubMed

    Beilharz, F; Castle, D J; Grace, S; Rossell, S L

    2017-07-01

    Recent advances in body dysmorphic disorder (BDD) have explored abnormal visual processing, yet it is unclear how this relates to treatment. The aim of this study was to summarize our current understanding of visual processing in BDD and review associated treatments. The literature was collected through PsycInfo and PubMed. Visual processing articles were included if written in English after 1970, had a specific BDD group compared to healthy controls and were not case studies. Due to the lack of research regarding treatments associated with visual processing, case studies were included. A number of visual processing abnormalities are present in BDD, including face recognition, emotion identification, aesthetics, object recognition and gestalt processing. Differences to healthy controls include a dominance of detailed local processing over global processing and associated changes in brain activation in visual regions. Perceptual mirror retraining and some forms of self-exposure have demonstrated improved treatment outcomes, but have not been examined in isolation from broader treatments. Despite these abnormalities in perception, particularly concerning face and emotion recognition, few BDD treatments attempt to specifically remediate this. The development of a novel visual training programme which addresses these widespread abnormalities may provide an effective treatment modality. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Women's experiences of coping with pregnancy termination for fetal abnormality.

    PubMed

    Lafarge, Caroline; Mitchell, Kathryn; Fox, Pauline

    2013-07-01

    Pregnancy termination for fetal abnormality (TFA) can have significant psychological consequences. Most previous research has been focused on measuring the psychological outcomes of TFA, and little is known about the coping strategies involved. In this article, we report on women's coping strategies used during and after the procedure. Our account is based on experiences of 27 women who completed an online survey. We analyzed the data using interpretative phenomenological analysis. Coping comprised four structures, consistent across time points: support, acceptance, avoidance, and meaning attribution. Women mostly used adaptive coping strategies but reported inadequacies in aftercare, which challenged their resources. The study's findings indicate the need to provide sensitive, nondirective care rooted in the acknowledgment of the unique nature of TFA. Enabling women to reciprocate for emotional support, promoting adaptive coping strategies, highlighting the potential value of spending time with the baby, and providing long-term support (including during subsequent pregnancies) might promote psychological adjustment to TFA.

  13. Specific problems in visual cognition of dyslexic readers: Face discrimination deficits predict dyslexia over and above discrimination of scrambled faces and novel objects.

    PubMed

    Sigurdardottir, Heida Maria; Fridriksdottir, Liv Elisabet; Gudjonsdottir, Sigridur; Kristjánsson, Árni

    2018-06-01

    Evidence of interdependencies of face and word processing mechanisms suggest possible links between reading problems and abnormal face processing. In two experiments we assessed such high-level visual deficits in people with a history of reading problems. Experiment 1 showed that people who were worse at face matching had greater reading problems. In experiment 2, matched dyslexic and typical readers were tested, and difficulties with face matching were consistently found to predict dyslexia over and above both novel-object matching as well as matching noise patterns that shared low-level visual properties with faces. Furthermore, ADHD measures could not account for face matching problems. We speculate that reading difficulties in dyslexia are partially caused by specific deficits in high-level visual processing, in particular for visual object categories such as faces and words with which people have extensive experience. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Experiences of Individuals with Visual Impairments in Integrated Physical Education: A Retrospective Study

    ERIC Educational Resources Information Center

    Haegele, Justin A.; Zhu, Xihe

    2017-01-01

    Purpose: The purpose of this retrospective study was to examine the experiences of adults with visual impairments during school-based integrated physical education (PE). Method: An interpretative phenomenological analysis (IPA) research approach was used and 16 adults (ages 21-48 years; 10 women, 6 men) with visual impairments acted as…

  15. Theta Oscillations in Visual Cortex Emerge with Experience to Convey Expected Reward Time and Experienced Reward Rate

    PubMed Central

    Zold, Camila L.

    2015-01-01

    The primary visual cortex (V1) is widely regarded as faithfully conveying the physical properties of visual stimuli. Thus, experience-induced changes in V1 are often interpreted as improving visual perception (i.e., perceptual learning). Here we describe how, with experience, cue-evoked oscillations emerge in V1 to convey expected reward time as well as to relate experienced reward rate. We show, in chronic multisite local field potential recordings from rat V1, that repeated presentation of visual cues induces the emergence of visually evoked oscillatory activity. Early in training, the visually evoked oscillations relate to the physical parameters of the stimuli. However, with training, the oscillations evolve to relate the time in which those stimuli foretell expected reward. Moreover, the oscillation prevalence reflects the reward rate recently experienced by the animal. Thus, training induces experience-dependent changes in V1 activity that relate to what those stimuli have come to signify behaviorally: when to expect future reward and at what rate. PMID:26134643

  16. Recognizing patterns of visual field loss using unsupervised machine learning

    NASA Astrophysics Data System (ADS)

    Yousefi, Siamak; Goldbaum, Michael H.; Zangwill, Linda M.; Medeiros, Felipe A.; Bowd, Christopher

    2014-03-01

    Glaucoma is a potentially blinding optic neuropathy that results in a decrease in visual sensitivity. Visual field abnormalities (decreased visual sensitivity on psychophysical tests) are the primary means of glaucoma diagnosis. One form of visual field testing is Frequency Doubling Technology (FDT) that tests sensitivity at 52 points within the visual field. Like other psychophysical tests used in clinical practice, FDT results yield specific patterns of defect indicative of the disease. We used Gaussian Mixture Model with Expectation Maximization (GEM), (EM is used to estimate the model parameters) to automatically separate FDT data into clusters of normal and abnormal eyes. Principal component analysis (PCA) was used to decompose each cluster into different axes (patterns). FDT measurements were obtained from 1,190 eyes with normal FDT results and 786 eyes with abnormal (i.e., glaucomatous) FDT results, recruited from a university-based, longitudinal, multi-center, clinical study on glaucoma. The GEM input was the 52-point FDT threshold sensitivities for all eyes. The optimal GEM model separated the FDT fields into 3 clusters. Cluster 1 contained 94% normal fields (94% specificity) and clusters 2 and 3 combined, contained 77% abnormal fields (77% sensitivity). For clusters 1, 2 and 3 the optimal number of PCA-identified axes were 2, 2 and 5, respectively. GEM with PCA successfully separated FDT fields from healthy and glaucoma eyes and identified familiar glaucomatous patterns of loss.

  17. Tactile Radar: experimenting a computer game with visually disabled.

    PubMed

    Kastrup, Virgínia; Cassinelli, Alvaro; Quérette, Paulo; Bergstrom, Niklas; Sampaio, Eliana

    2017-09-18

    Visually disabled people increasingly use computers in everyday life, thanks to novel assistive technologies better tailored to their cognitive functioning. Like sighted people, many are interested in computer games - videogames and audio-games. Tactile-games are beginning to emerge. The Tactile Radar is a device through which a visually disabled person is able to detect distal obstacles. In this study, it is connected to a computer running a tactile-game. The game consists in finding and collecting randomly arranged coins in a virtual room. The study was conducted with nine congenital blind people including both sexes, aged 20-64 years old. Complementary methods of first and third person were used: the debriefing interview and the quasi-experimental design. The results indicate that the Tactile Radar is suitable for the creation of computer games specifically tailored for visually disabled people. Furthermore, the device seems capable of eliciting a powerful immersive experience. Methodologically speaking, this research contributes to the consolidation and development of first and third person complementary methods, particularly useful in disabled people research field, including the evaluation by users of the Tactile Radar effectiveness in a virtual reality context. Implications for rehabilitation Despite the growing interest in virtual games for visually disabled people, they still find barriers to access such games. Through the development of assistive technologies such as the Tactile Radar, applied in virtual games, we can create new opportunities for leisure, socialization and education for visually disabled people. The results of our study indicate that the Tactile Radar is adapted to the creation of video games for visually disabled people, providing a playful interaction with the players.

  18. Age, School Experience and the Development of Visual-Perceptual Memory. Final Report, Part 2.

    ERIC Educational Resources Information Center

    Goulet, L. R.

    This study attempted to investigate the effects of school experience on visual perception tests involving line figures and forms. There were two experiments in this study. Experiment 1 examined the independent and interactive influences of school experience and chronological age in kindergarten children. Experiment 2 compared the effects of…

  19. Autistic Traits and Abnormal Sensory Experiences in Adults

    ERIC Educational Resources Information Center

    Horder, Jamie; Wilson, C. Ellie; Mendez, M. Andreina; Murphy, Declan G.

    2014-01-01

    Sensory processing abnormalities are common in autism spectrum disorders (ASD), and now form part of the "Diagnostic and Statistical Manual 5th Edition" (DSM-5) diagnostic criteria, but it is unclear whether they characterize the "broader phenotype" of the disorder. We recruited adults (n = 772) with and without an ASD and…

  20. Arousal Rules: An Empirical Investigation into the Aesthetic Experience of Cross-Modal Perception with Emotional Visual Music

    PubMed Central

    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

  1. Arousal Rules: An Empirical Investigation into the Aesthetic Experience of Cross-Modal Perception with Emotional Visual Music.

    PubMed

    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.

  2. On the role of visual experience in mathematical development: Evidence from blind mathematicians.

    PubMed

    Amalric, Marie; Denghien, Isabelle; Dehaene, Stanislas

    2018-04-01

    Advanced mathematical reasoning, regardless of domain or difficulty, activates a reproducible set of bilateral brain areas including intraparietal, inferior temporal and dorsal prefrontal cortex. The respective roles of genetics, experience and education in the development of this math-responsive network, however, remain unresolved. Here, we investigate the role of visual experience by studying the exceptional case of three professional mathematicians who were blind from birth (n=1) or became blind during childhood (n=2). Subjects were scanned with fMRI while they judged the truth value of spoken mathematical and nonmathematical statements. Blind mathematicians activated the classical network of math-related areas during mathematical reflection, similar to that found in a group of sighted professional mathematicians. Thus, brain networks for advanced mathematical reasoning can develop in the absence of visual experience. Additional activations were found in occipital cortex, even in individuals who became blind during childhood, suggesting that either mental imagery or a more radical repurposing of visual cortex may occur in blind mathematicians. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Psychopathology of Lived Time: Abnormal Time Experience in Persons With Schizophrenia.

    PubMed

    Stanghellini, Giovanni; Ballerini, Massimo; Presenza, Simona; Mancini, Milena; Raballo, Andrea; Blasi, Stefano; Cutting, John

    2016-01-01

    Abnormal time experience (ATE) in schizophrenia is a long-standing theme of phenomenological psychopathology. This is because temporality constitutes the bedrock of any experience and its integrity is fundamental for the sense of coherence and continuity of selfhood and personal identity. To characterize ATE in schizophrenia patients as compared to major depressives we interviewed, in a clinical setting over a period of 15 years, 550 consecutive patients affected by schizophrenic and affective disorders. Clinical files were analyzed by means of Consensual Qualitative Research (CQR), an inductive method suited to research that requires rich descriptions of inner experiences. Of the whole sample, 109 persons affected by schizophrenic (n = 95 acute, n = 14 chronic) and 37 by major depression reported at least 1 ATE. ATE are more represented in acute (N = 109 out of 198; 55%) than in chronic schizophrenic patients (N = 14 out of 103; 13%). The main feature of ATE in people with schizophrenia is the fragmentation of time experience (71 out of 109 patients), an impairment of the automatic and prereflexive synthesis of primal impression-retention-protention. This includes 4 subcategories: disruption of time flowing, déjà vu/vecu, premonitions about oneself and the external world. We contrasted ATE in schizophrenia and in major depression, finding relevant differences: in major depressives there is no disarticulation of time experience, rather timelessness because time lacks duration, not articulation. These core features of the schizophrenic pheno-phenotype may be related to self-disorders and to the manifold of characteristic schizophrenic symptoms, including so called bizarre delusions and verbal-acoustic hallucinations. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  4. STS-47 Payload Specialist Mohri conducts visual stability experiment in SLJ

    NASA Image and Video Library

    1992-09-20

    STS047-204-006 (12 - 20 Sept 1992) --- Dr. Mamoru Mohri, payload specialist representing Japan's National Space Development Agency (NASDA), participates in an experiment designed to learn more about Space Adaptation Syndrome (SAS). The experiment is titled, "Comparative Measurement of Visual Stability in Earth and Cosmic Space." During the experiment, Dr. Mohri tracked a flickering light target while eye movements and neck muscle tension were measured. This 45-degree angle position was one of four studied during the eight-day Spacelab-J mission.

  5. Visual Aversive Learning Compromises Sensory Discrimination.

    PubMed

    Shalev, Lee; Paz, Rony; Avidan, Galia

    2018-03-14

    Aversive learning is thought to modulate perceptual thresholds, which can lead to overgeneralization. However, it remains undetermined whether this modulation is domain specific or a general effect. Moreover, despite the unique role of the visual modality in human perception, it is unclear whether this aspect of aversive learning exists in this modality. The current study was designed to examine the effect of visual aversive outcomes on the perception of basic visual and auditory features. We tested the ability of healthy participants, both males and females, to discriminate between neutral stimuli, before and after visual learning. In each experiment, neutral stimuli were associated with aversive images in an experimental group and with neutral images in a control group. Participants demonstrated a deterioration in discrimination (higher discrimination thresholds) only after aversive learning. This deterioration was measured for both auditory (tone frequency) and visual (orientation and contrast) features. The effect was replicated in five different experiments and lasted for at least 24 h. fMRI neural responses and pupil size were also measured during learning. We showed an increase in neural activations in the anterior cingulate cortex, insula, and amygdala during aversive compared with neutral learning. Interestingly, the early visual cortex showed increased brain activity during aversive compared with neutral context trials, with identical visual information. Our findings imply the existence of a central multimodal mechanism, which modulates early perceptual properties, following exposure to negative situations. Such a mechanism could contribute to abnormal responses that underlie anxiety states, even in new and safe environments. SIGNIFICANCE STATEMENT Using a visual aversive-learning paradigm, we found deteriorated discrimination abilities for visual and auditory stimuli that were associated with visual aversive stimuli. We showed increased neural

  6. Impact of audio-visual storytelling in simulation learning experiences of undergraduate nursing students.

    PubMed

    Johnston, Sandra; Parker, Christina N; Fox, Amanda

    2017-09-01

    Use of high fidelity simulation has become increasingly popular in nursing education to the extent that it is now an integral component of most nursing programs. Anecdotal evidence suggests that students have difficulty engaging with simulation manikins due to their unrealistic appearance. Introduction of the manikin as a 'real patient' with the use of an audio-visual narrative may engage students in the simulated learning experience and impact on their learning. A paucity of literature currently exists on the use of audio-visual narratives to enhance simulated learning experiences. This study aimed to determine if viewing an audio-visual narrative during a simulation pre-brief altered undergraduate nursing student perceptions of the learning experience. A quasi-experimental post-test design was utilised. A convenience sample of final year baccalaureate nursing students at a large metropolitan university. Participants completed a modified version of the Student Satisfaction with Simulation Experiences survey. This 12-item questionnaire contained questions relating to the ability to transfer skills learned in simulation to the real clinical world, the realism of the simulation and the overall value of the learning experience. Descriptive statistics were used to summarise demographic information. Two tailed, independent group t-tests were used to determine statistical differences within the categories. Findings indicated that students reported high levels of value, realism and transferability in relation to the viewing of an audio-visual narrative. Statistically significant results (t=2.38, p<0.02) were evident in the subscale of transferability of learning from simulation to clinical practice. The subgroups of age and gender although not significant indicated some interesting results. High satisfaction with simulation was indicated by all students in relation to value and realism. There was a significant finding in relation to transferability on knowledge and this

  7. Visual outcome after endoscopic third ventriculostomy for hydrocephalus.

    PubMed

    Jung, Ji-Ho; Chai, Yong-Hyun; Jung, Shin; Kim, In-Young; Jang, Woo-Youl; Moon, Kyung-Sub; Kim, Seul-Kee; Chong, Sangjoon; Kim, Seung-Ki; Jung, Tae-Young

    2018-02-01

    Hydrocephalus-related symptoms are mostly improved after successful endoscopic third ventriculostomy (ETV). However, visual symptoms can be different. This study was focused on visual symptoms. We analyzed the magnetic resonance images (MRI) of the orbit and visual outcomes. From August 2006 to November 2016, 50 patients with hydrocephalus underwent ETV. The male-to-female ratio was 33:17, and the median age was 61 years (range, 5-74 years). There were 18 pediatric and 32 adult patients. Abnormal orbital MRI findings included prominent subarachnoid space around the optic nerves and vertical tortuosity of the optic nerves. We retrospectively analyzed clinical symptoms, causes of hydrocephalus, ETV success score (ETVSS), ETV success rate, ETV complications, orbital MRI findings, and visual impairment score (VIS). The median duration of follow-up was 59 months (range, 3-113 months). The most common symptoms were headache, vomiting, and gait disturbance. Visual symptoms were found in 6 patients (12%). The most common causes of hydrocephalus were posterior fossa tumor in 13 patients, pineal tumor in 12, aqueductal stenosis in 8, thalamic malignant glioma in 7, and tectal glioma in 4. ETVSS was 70 in 3 patients, 80 in 34 patients, and 90 in 13 patients. ETV success rate was 80%. ETVSS 70 showed the trend in short-term survival compared to ETVSS 90 and 80. ETV complications included epidural hematoma requiring operation in one patient, transient hemiparesis in two patients, and infection in two patients. Preoperative abnormal orbital MRI findings were found in 18 patients and postoperative findings in 7 patients. Four of six patients with visual symptoms had abnormal MR findings. Three patients did not show VIS improvement, including two with severe visual symptoms. Patients with severe visual impairment were found to have bad outcomes. The visual symptoms related with increased intracranial pressure should be carefully monitored and controlled to improve outcomes.

  8. Binocular visual training to promote recovery from monocular deprivation.

    PubMed

    Murphy, Kathryn M; Roumeliotis, Grayson; Williams, Kate; Beston, Brett R; Jones, David G

    2015-01-08

    Abnormal early visual experience often leads to poor vision, a condition called amblyopia. Two recent approaches to treating amblyopia include binocular therapies and intensive visual training. These reflect the emerging view that amblyopia is a binocular deficit caused by increased neural noise and poor signal-in-noise integration. Most perceptual learning studies have used monocular training; however, a recent study has shown that binocular training is effective for improving acuity in adult human amblyopes. We used an animal model of amblyopia, based on monocular deprivation, to compare the effect of binocular training either during or after the critical period for ocular dominance plasticity (early binocular training vs. late binocular training). We used a high-contrast, orientation-in-noise stimulus to drive the visual cortex because neurophysiological findings suggest that binocular training may allow the nondeprived eye to teach the deprived eye's circuits to function. We found that both early and late binocular training promoted good visual recovery. Surprisingly, we found that monocular deprivation caused a permanent deficit in the vision of both eyes, which became evident only as a sleeper effect following many weeks of visual training. © 2015 ARVO.

  9. Intermittently-visual Tracking Experiments Reveal the Roles of Error-correction and Predictive Mechanisms in the Human Visual-motor Control System

    NASA Astrophysics Data System (ADS)

    Hayashi, Yoshikatsu; Tamura, Yurie; Sase, Kazuya; Sugawara, Ken; Sawada, Yasuji

    Prediction mechanism is necessary for human visual motion to compensate a delay of sensory-motor system. In a previous study, “proactive control” was discussed as one example of predictive function of human beings, in which motion of hands preceded the virtual moving target in visual tracking experiments. To study the roles of the positional-error correction mechanism and the prediction mechanism, we carried out an intermittently-visual tracking experiment where a circular orbit is segmented into the target-visible regions and the target-invisible regions. Main results found in this research were following. A rhythmic component appeared in the tracer velocity when the target velocity was relatively high. The period of the rhythm in the brain obtained from environmental stimuli is shortened more than 10%. The shortening of the period of rhythm in the brain accelerates the hand motion as soon as the visual information is cut-off, and causes the precedence of hand motion to the target motion. Although the precedence of the hand in the blind region is reset by the environmental information when the target enters the visible region, the hand motion precedes the target in average when the predictive mechanism dominates the error-corrective mechanism.

  10. Analysis of experience-regulated transcriptome and imprintome during critical periods of mouse visual system development reveals spatiotemporal dynamics.

    PubMed

    Hsu, Chi-Lin; Chou, Chih-Hsuan; Huang, Shih-Chuan; Lin, Chia-Yi; Lin, Meng-Ying; Tung, Chun-Che; Lin, Chun-Yen; Lai, Ivan Pochou; Zou, Yan-Fang; Youngson, Neil A; Lin, Shau-Ping; Yang, Chang-Hao; Chen, Shih-Kuo; Gau, Susan Shur-Fen; Huang, Hsien-Sung

    2018-03-15

    Visual system development is light-experience dependent, which strongly implicates epigenetic mechanisms in light-regulated maturation. Among many epigenetic processes, genomic imprinting is an epigenetic mechanism through which monoallelic gene expression occurs in a parent-of-origin-specific manner. It is unknown if genomic imprinting contributes to visual system development. We profiled the transcriptome and imprintome during critical periods of mouse visual system development under normal- and dark-rearing conditions using B6/CAST F1 hybrid mice. We identified experience-regulated, isoform-specific and brain-region-specific imprinted genes. We also found imprinted microRNAs were predominantly clustered into the Dlk1-Dio3 imprinted locus with light experience affecting some imprinted miRNA expression. Our findings provide the first comprehensive analysis of light-experience regulation of the transcriptome and imprintome during critical periods of visual system development. Our results may contribute to therapeutic strategies for visual impairments and circadian rhythm disorders resulting from a dysfunctional imprintome.

  11. A Quantitative Analysis of the Work Experiences of Adults with Visual Impairments in Nigeria

    ERIC Educational Resources Information Center

    Wolffe, Karen E.; Ajuwon, Paul M.; Kelly, Stacy M.

    2013-01-01

    Introduction: Worldwide, people with visual impairments often struggle to gain employment. This study attempts to closely evaluate the work experiences of employed individuals with visual impairments living in one of the world's most populous developing nations, Nigeria. Methods: The researchers developed a questionnaire that assessed personal and…

  12. Garbage Patch Visualization Experiment

    NASA Image and Video Library

    2015-08-20

    Goddard visualizers show us how five garbage patches formed in the world's oceans using 35 years of data. Read more: 1.usa.gov/1Lnj7xV Credit: NASA's Scientific Visualization Studio NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  13. The effects of chlorpromazine and lorazepam on abnormal antisaccade and no-saccade distractibility.

    PubMed

    Green, J F; King, D J

    1998-10-15

    Abnormally high levels of saccadic distractibility have been demonstrated to occur in patients with schizophrenia. Converging evidence implicates frontal cortical dysfunction as a mechanism; however, much of the neuropharmacology of saccadic distractibility has not yet been established. We measured antisaccade, no-saccade, and visually guided saccade components in healthy subjects following single doses of lorazepam 2 mg, chlorpromazine 50-100 mg, and placebo. Visual analogue rating scales (VARS) provided a subjective measure of sedation. Lorazepam, but not chlorpromazine, was shown to cause an increase in saccadic distractibility in both the antisaccade and no-saccade tasks. Peak visually guided saccade velocity was decreased by lorazepam and chlorpromazine in a dose-dependent manner, with corresponding changes seen in VARS. Lorazepam, unexpectedly, did not affect peak antisaccade velocity. The background level of antisaccade directional errors was 6.43%, which is relatively low compared to control groups in patient studies. These results support the view that abnormal saccadic distractibility in patients with schizophrenia is not due to an acute effect of antipsychotic medication. The use of benzodiazepines and the level of task practice are highlighted as possible confounding variables in patient studies. The implications of these results for the current neuropathological theories of abnormal saccadic distractibility are discussed.

  14. Visual attention shifting in autism spectrum disorders.

    PubMed

    Richard, Annette E; Lajiness-O'Neill, Renee

    2015-01-01

    Abnormal visual attention has been frequently observed in autism spectrum disorders (ASD). Abnormal shifting of visual attention is related to abnormal development of social cognition and has been identified as a key neuropsychological finding in ASD. Better characterizing attention shifting in ASD and its relationship with social functioning may help to identify new targets for intervention and improving social communication in these disorders. Thus, the current study investigated deficits in attention shifting in ASD as well as relationships between attention shifting and social communication in ASD and neurotypicals (NT). To investigate deficits in visual attention shifting in ASD, 20 ASD and 20 age- and gender-matched NT completed visual search (VS) and Navon tasks with attention-shifting demands as well as a set-shifting task. VS was a feature search task with targets defined in one of two dimensions; Navon required identification of a target letter presented at the global or local level. Psychomotor and processing speed were entered as covariates. Relationships between visual attention shifting, set shifting, and social functioning were also examined. ASD and NT showed comparable costs of shifting attention. However, psychomotor and processing speed were slower in ASD than in NT, and psychomotor and processing speed were positively correlated with attention-shifting costs on Navon and VS, respectively, for both groups. Attention shifting on VS and Navon were correlated among NT, while attention shifting on Navon was correlated with set shifting among ASD. Attention-shifting costs on Navon were positively correlated with restricted and repetitive behaviors among ASD. Relationships between attention shifting and psychomotor and processing speed, as well as relationships between measures of different aspects of visual attention shifting, suggest inefficient top-down influences over preattentive visual processing in ASD. Inefficient attention shifting may be

  15. Natural History of the Central Structural Abnormalities in Choroideremia: A Prospective Cross-Sectional Study.

    PubMed

    Aleman, Tomas S; Han, Grace; Serrano, Leona W; Fuerst, Nicole M; Charlson, Emily S; Pearson, Denise J; Chung, Daniel C; Traband, Anastasia; Pan, Wei; Ying, Gui-Shuang; Bennett, Jean; Maguire, Albert M; Morgan, Jessica I W

    2017-03-01

    To describe in detail the central retinal structure of a large group of patients with choroideremia (CHM). A prospective, cross-sectional, descriptive study. Patients (n = 97, age 6-71 years) with CHM and subjects with normal vision (n = 44; ages 10-50 years) were included. Subjects were examined with spectral-domain optical coherence tomography (SD OCT) and near-infrared reflectance imaging. Visual acuity (VA) was measured during their encounter or obtained from recent ophthalmic examinations. Visual thresholds were measured in a subset of patients (n = 24) with automated static perimetry within the central regions (±15°) examined with SD OCT. Visual acuity and visual thresholds; total nuclear layer, inner nuclear layer (INL), and outer nuclear layer (ONL) thicknesses; and horizontal extent of the ONL and the photoreceptor outer segment (POS) interdigitation zone (IZ). Earliest abnormalities in regions with normally appearing retinal pigment epithelium (RPE) were the loss of the POS and ellipsoid zone associated with rod dysfunction. Transition zones (TZs) from relatively preserved retina to severe ONL thinning and inner retinal thickening moved centripetally with age. Most patients (88%) retained VAs better than 20/40 until their fifth decade of life. The VA decline coincided with migration of the TZ near the foveal center. There were outer retinal tubulations in degenerated, nonatrophic retina in the majority (69%) of patients. In general, RPE abnormalities paralleled photoreceptor degeneration, although there were regions with detectable but abnormally thin ONL co-localizing with severe RPE depigmentation and choroidal thinning. Abnormalities of the POS and rod dysfunction are the earliest central abnormalities observed in CHM. Foveal function is relatively preserved until the fifth decade of life. Migration of the TZs to the foveal center with foveal thinning and structural disorganization heralded central VA loss. The relationships established may help

  16. High resolution renderings and interactive visualization of the 2006 Huntington Beach experiment

    NASA Astrophysics Data System (ADS)

    Im, T.; Nayak, A.; Keen, C.; Samilo, D.; Matthews, J.

    2006-12-01

    The Visualization Center at the Scripps Institution of Oceanography investigates innovative ways to represent graphically interactive 3D virtual landscapes and to produce high resolution, high quality renderings of Earth sciences data and the sensors and instruments used to collect the data . Among the Visualization Center's most recent work is the visualization of the Huntington Beach experiment, a study launched in July 2006 by the Southern California Ocean Observing System (http://www.sccoos.org/) to record and synthesize data of the Huntington Beach coastal region. Researchers and students at the Visualization Center created visual presentations that combine bathymetric data provided by SCCOOS with USGS aerial photography and with 3D polygonal models of sensors created in Maya into an interactive 3D scene using the Fledermaus suite of visualization tools (http://www.ivs3d.com). In addition, the Visualization Center has produced high definition (HD) animations of SCCOOS sensor instruments (e.g. REMUS, drifters, spray glider, nearshore mooring, OCSD/USGS mooring and CDIP mooring) using the Maya modeling and animation software and rendered over multiple nodes of the OptIPuter Visualization Cluster at Scripps. These visualizations are aimed at providing researchers with a broader context of sensor locations relative to geologic characteristics, to promote their use as an educational resource for informal education settings and increasing public awareness, and also as an aid for researchers' proposals and presentations. These visualizations are available for download on the Visualization Center website at http://siovizcenter.ucsd.edu/sccoos/hb2006.php.

  17. Insensitivity of visual short-term memory to irrelevant visual information.

    PubMed

    Andrade, Jackie; Kemps, Eva; Werniers, Yves; May, Jon; Szmalec, Arnaud

    2002-07-01

    Several authors have hypothesized that visuo-spatial working memory is functionally analogous to verbal working memory. Irrelevant background speech impairs verbal short-term memory. We investigated whether irrelevant visual information has an analogous effect on visual short-term memory, using a dynamic visual noise (DVN) technique known to disrupt visual imagery (Quinn & McConnell, 1996b). Experiment I replicated the effect of DVN on pegword imagery. Experiments 2 and 3 showed no effect of DVN on recall of static matrix patterns, despite a significant effect of a concurrent spatial tapping task. Experiment 4 showed no effect of DVN on encoding or maintenance of arrays of matrix patterns, despite testing memory by a recognition procedure to encourage visual rather than spatial processing. Serial position curves showed a one-item recency effect typical of visual short-term memory. Experiment 5 showed no effect of DVN on short-term recognition of Chinese characters, despite effects of visual similarity and a concurrent colour memory task that confirmed visual processing of the characters. We conclude that irrelevant visual noise does not impair visual short-term memory. Visual working memory may not be functionally analogous to verbal working memory, and different cognitive processes may underlie visual short-term memory and visual imagery.

  18. Initial experience with visualizing hand and foot tendons by dual-energy computed tomography.

    PubMed

    Deng, Kai; Sun, Cong; Liu, Cheng; Ma, Rui

    2009-01-01

    To assess the feasibility of visualizing hand and foot tendons by dual-energy computed tomography (CT). Twenty patients who suffered from hand or feet pains were scanned on dual-source CT (Definition, Forchheim, Germany) with dual-energy mode at tube voltages of 140 and 80 kV and a corresponding ratio of 1:4 between tube currents. The reconstructed images were postprocessed by volume rendering techniques (VRT) and multiplanar reconstruction (MPR). All of the suspected lesions were confirmed by surgery or follow-up studies. Twelve patients (total of 24 hands and feet, respectively) were found to be normal and the other eight patients (total of nine hands and feet, respectively) were found abnormal. Dual-energy techniques are very useful in visualizing tendons of the hands and feet, such as flexor pollicis longus tendon, flexor digitorum superficialis/profundus tendon, Achilles tendon, extensor hallucis longus tendon, and extensor digitorum longus tendon, etc. It can depict the whole shape of the tendons and their fixation points clearly. Peroneus longus tendon in the sole of the foot was not displayed very well. The distal ends of metacarpophalangeal joints with extensor digitoium tendon and extensor pollicis longus tendon were poorly shown. The lesions of tendons such as the circuitry, thickening, and adherence were also shown clearly. Dual-energy CT offers a new method to visualize tendons of the hand and foot. It could clearly display both anatomical structures and pathologic changes of hand and foot tendons.

  19. Long-term visual outcomes in extremely low-birth-weight children (an American Ophthalmological Society thesis).

    PubMed

    Spencer, Rand

    2006-01-01

    The goal is to analyze the long-term visual outcome of extremely low-birth-weight children. This is a retrospective analysis of eyes of extremely low-birth-weight children on whom vision testing was performed. Visual outcomes were studied by analyzing acuity outcomes at >/=36 months of adjusted age, correlating early acuity testing with final visual outcome and evaluating adverse risk factors for vision. Data from 278 eyes are included. Mean birth weight was 731g, and mean gestational age at birth was 26 weeks. 248 eyes had grating acuity outcomes measured at 73 +/- 36 months, and 183 eyes had recognition acuity testing at 76 +/- 39 months. 54% had below normal grating acuities, and 66% had below normal recognition acuities. 27% of grating outcomes and 17% of recognition outcomes were Abnormal early grating acuity testing was predictive of abnormal grating (P < .0001) and recognition (P = .0001) acuity testing at >/=3 years of age. A slower-than-normal rate of early visual development was predictive of abnormal grating acuity (P < .0001) and abnormal recognition acuity (P < .0001) at >/=3 years of age. Eyes diagnosed with maximal retinopathy of prematurity in zone I had lower acuity outcomes (P = .0002) than did those with maximal retinopathy of prematurity in zone II/III. Eyes of children born at abnormal recognition acuity than did those of children born at >28 weeks gestational age. Eyes of children with poorer general health after premature birth had a 5.3 times greater risk of abnormal recognition acuity. Long-term visual development in extremely low-birth-weight infants is problematic and associated with a high risk of subnormal acuity. Early acuity testing is useful in identifying children at greatest risk for long-term visual abnormalities. Gestational age at birth of abnormal long-term outcome.

  20. LONG-TERM VISUAL OUTCOMES IN EXTREMELY LOW-BIRTH-WEIGHT CHILDREN (AN AMERICAN OPHTHALMOLOGICAL SOCIETY THESIS)

    PubMed Central

    Spencer, Rand

    2006-01-01

    Purpose The goal is to analyze the long-term visual outcome of extremely low-birth-weight children. Methods This is a retrospective analysis of eyes of extremely low-birth-weight children on whom vision testing was performed. Visual outcomes were studied by analyzing acuity outcomes at ≥36 months of adjusted age, correlating early acuity testing with final visual outcome and evaluating adverse risk factors for vision. Results Data from 278 eyes are included. Mean birth weight was 731g, and mean gestational age at birth was 26 weeks. 248 eyes had grating acuity outcomes measured at 73 ± 36 months, and 183 eyes had recognition acuity testing at 76 ± 39 months. 54% had below normal grating acuities, and 66% had below normal recognition acuities. 27% of grating outcomes and 17% of recognition outcomes were ≤20/200. Abnormal early grating acuity testing was predictive of abnormal grating (P < .0001) and recognition (P = .0001) acuity testing at ≥3 years of age. A slower-than-normal rate of early visual development was predictive of abnormal grating acuity (P < .0001) and abnormal recognition acuity (P < .0001) at ≥3 years of age. Eyes diagnosed with maximal retinopathy of prematurity in zone I had lower acuity outcomes (P = .0002) than did those with maximal retinopathy of prematurity in zone II/III. Eyes of children born at ≤28 weeks gestational age had 4.1 times greater risk for abnormal recognition acuity than did those of children born at >28 weeks gestational age. Eyes of children with poorer general health after premature birth had a 5.3 times greater risk of abnormal recognition acuity. Conclusions Long-term visual development in extremely low-birth-weight infants is problematic and associated with a high risk of subnormal acuity. Early acuity testing is useful in identifying children at greatest risk for long-term visual abnormalities. Gestational age at birth of ≤ 28 weeks was associated with a higher risk of an abnormal long-term outcome. PMID

  1. Interactive Visualization of Infrared Spectral Data: Synergy of Computation, Visualization, and Experiment for Learning Spectroscopy

    NASA Astrophysics Data System (ADS)

    Lahti, Paul M.; Motyka, Eric J.; Lancashire, Robert J.

    2000-05-01

    A straightforward procedure is described to combine computation of molecular vibrational modes using commonly available molecular modeling programs with visualization of the modes using advanced features of the MDL Information Systems Inc. Chime World Wide Web browser plug-in. Minor editing of experimental spectra that are stored in the JCAMP-DX format allows linkage of IR spectral frequency ranges to Chime molecular display windows. The spectra and animation files can be combined by Hypertext Markup Language programming to allow interactive linkage between experimental spectra and computationally generated vibrational displays. Both the spectra and the molecular displays can be interactively manipulated to allow the user maximum control of the objects being viewed. This procedure should be very valuable not only for aiding students through visual linkage of spectra and various vibrational animations, but also by assisting them in learning the advantages and limitations of computational chemistry by comparison to experiment.

  2. Modernized Approach for Generating Reproducible Heterogeneity Using Transmitted-Light for Flow Visualization Experiments

    NASA Astrophysics Data System (ADS)

    Jones, A. A.; Holt, R. M.

    2017-12-01

    Image capturing in flow experiments has been used for fluid mechanics research since the early 1970s. Interactions of fluid flow between the vadose zone and permanent water table are of great interest because this zone is responsible for all recharge waters, pollutant transport and irrigation efficiency for agriculture. Griffith, et al. (2011) developed an approach where constructed reproducible "geologically realistic" sand configurations are deposited in sandfilled experimental chambers for light-transmitted flow visualization experiments. This method creates reproducible, reverse graded, layered (stratified) thin-slab sand chambers for point source experiments visualizing multiphase flow through porous media. Reverse-graded stratification of sand chambers mimic many naturally occurring sedimentary deposits. Sandfilled chambers use light as nonintrusive tools for measuring water saturation in two-dimensions (2-D). Homogeneous and heterogeneous sand configurations can be produced to visualize the complex physics of the unsaturated zone. The experimental procedure developed by Griffith, et al. (2011) was designed using now outdated and obsolete equipment. We have modernized this approach with new Parker Deadel linear actuator and programed projects/code for multiple configurations. We have also updated the Roper CCD software and image processing software with the latest in industry standards. Modernization of transmitted-light source, robotic equipment, redesigned experimental chambers, and newly developed analytical procedures have greatly reduced time and cost per experiment. We have verified the ability of the new equipment to generate reproducible heterogeneous sand-filled chambers and demonstrated the functionality of the new equipment and procedures by reproducing several gravity-driven fingering experiments conducted by Griffith (2008).

  3. Braille and Tactile Graphics: Youths with Visual Impairments Share Their Experiences

    ERIC Educational Resources Information Center

    Rosenblum, L. Penny; Herzberg, Tina S.

    2015-01-01

    Introduction: Data were collected from youths with visual impairment about their experiences with tactile graphics and braille materials used in mathematics and science classes. Methods: Youths answered questions and explored four tactile graphics made using different production methods. They located specific information on each graphic and shared…

  4. Asymmetric latent semantic indexing for gene expression experiments visualization.

    PubMed

    González, Javier; Muñoz, Alberto; Martos, Gabriel

    2016-08-01

    We propose a new method to visualize gene expression experiments inspired by the latent semantic indexing technique originally proposed in the textual analysis context. By using the correspondence word-gene document-experiment, we define an asymmetric similarity measure of association for genes that accounts for potential hierarchies in the data, the key to obtain meaningful gene mappings. We use the polar decomposition to obtain the sources of asymmetry of the similarity matrix, which are later combined with previous knowledge. Genetic classes of genes are identified by means of a mixture model applied in the genes latent space. We describe the steps of the procedure and we show its utility in the Human Cancer dataset.

  5. Augmented Visual Experience of Simulated Solar Phenomena

    NASA Astrophysics Data System (ADS)

    Tucker, A. O., IV; Berardino, R. A.; Hahne, D.; Schreurs, B.; Fox, N. J.; Raouafi, N.

    2017-12-01

    The Parker Solar Probe (PSP) mission will explore the Sun's corona, studying solar wind, flares and coronal mass ejections. The effects of these phenomena can impact the technology that we use in ways that are not readily apparent, including affecting satellite communications and power grids. Determining the structure and dynamics of corona magnetic fields, tracing the flow of energy that heats the corona, and exploring dusty plasma near the Sun to understand its influence on solar wind and energetic particle formation requires a suite of sensors on board the PSP spacecraft that are engineered to observe specific phenomena. Using models of these sensors and simulated observational data, we can visualize what the PSP spacecraft will "see" during its multiple passes around the Sun. Augmented reality (AR) technologies enable convenient user access to massive data sets. We are developing an application that allows users to experience environmental data from the point of view of the PSP spacecraft in AR using the Microsoft HoloLens. Observational data, including imagery, magnetism, temperature, and density are visualized in 4D within the user's immediate environment. Our application provides an educational tool for comprehending the complex relationships of observational data, which aids in our understanding of the Sun.

  6. Infant Face Preferences after Binocular Visual Deprivation

    ERIC Educational Resources Information Center

    Mondloch, Catherine J.; Lewis, Terri L.; Levin, Alex V.; Maurer, Daphne

    2013-01-01

    Early visual deprivation impairs some, but not all, aspects of face perception. We investigated the possible developmental roots of later abnormalities by using a face detection task to test infants treated for bilateral congenital cataract within 1 hour of their first focused visual input. The seven patients were between 5 and 12 weeks old…

  7. Teaching the Mammalian Heart to the Visually Handicapped--A Lesson in Concrete Experience

    ERIC Educational Resources Information Center

    Francoeur, Pearl; Eilam, Bihah

    1975-01-01

    Utilizes programmed instruction with concrete experiences and raised diagrams to teach the mammalian heart to an integrated high school classroom (one containing sighted and visually handicapped students). (LS)

  8. Environmental Enrichment Promotes Plasticity and Visual Acuity Recovery in Adult Monocular Amblyopic Rats

    PubMed Central

    Bonaccorsi, Joyce; Cenni, Maria Cristina; Sale, Alessandro; Maffei, Lamberto

    2012-01-01

    Loss of visual acuity caused by abnormal visual experience during development (amblyopia) is an untreatable pathology in adults. In some occasions, amblyopic patients loose vision in their better eye owing to accidents or illnesses. While this condition is relevant both for its clinical importance and because it represents a case in which binocular interactions in the visual cortex are suppressed, it has scarcely been studied in animal models. We investigated whether exposure to environmental enrichment (EE) is effective in triggering recovery of vision in adult amblyopic rats rendered monocular by optic nerve dissection in their normal eye. By employing both electrophysiological and behavioral assessments, we found a full recovery of visual acuity in enriched rats compared to controls reared in standard conditions. Moreover, we report that EE modulates the expression of GAD67 and BDNF. The non invasive nature of EE renders this paradigm promising for amblyopia therapy in adult monocular people. PMID:22509358

  9. The Pea Seedling as a Model of Normal and Abnormal Morphogenesis

    ERIC Educational Resources Information Center

    Kurkdjian, Armen; And Others

    1974-01-01

    Describes several simple and inexpensive experiments designed to facilitate the study of normal and abnormal morphogenesis in the biology laboratory. Seedlings of the common garden pea are used in the experiments, and abnormal morphogenesis (tumors) are induced by a virulent strain of the crown-gall organism, Agrobacterium tumefaciens. (JR)

  10. Visual Network Asymmetry and Default Mode Network Function in ADHD: An fMRI Study

    PubMed Central

    Hale, T. Sigi; Kane, Andrea M.; Kaminsky, Olivia; Tung, Kelly L.; Wiley, Joshua F.; McGough, James J.; Loo, Sandra K.; Kaplan, Jonas T.

    2014-01-01

    Background: A growing body of research has identified abnormal visual information processing in attention-deficit hyperactivity disorder (ADHD). In particular, slow processing speed and increased reliance on visuo-perceptual strategies have become evident. Objective: The current study used recently developed fMRI methods to replicate and further examine abnormal rightward biased visual information processing in ADHD and to further characterize the nature of this effect; we tested its association with several large-scale distributed network systems. Method: We examined fMRI BOLD response during letter and location judgment tasks, and directly assessed visual network asymmetry and its association with large-scale networks using both a voxelwise and an averaged signal approach. Results: Initial within-group analyses revealed a pattern of left-lateralized visual cortical activity in controls but right-lateralized visual cortical activity in ADHD children. Direct analyses of visual network asymmetry confirmed atypical rightward bias in ADHD children compared to controls. This ADHD characteristic was atypically associated with reduced activation across several extra-visual networks, including the default mode network (DMN). We also found atypical associations between DMN activation and ADHD subjects’ inattentive symptoms and task performance. Conclusion: The current study demonstrated rightward VNA in ADHD during a simple letter discrimination task. This result adds an important novel consideration to the growing literature identifying abnormal visual processing in ADHD. We postulate that this characteristic reflects greater perceptual engagement of task-extraneous content, and that it may be a basic feature of less efficient top-down task-directed control over visual processing. We additionally argue that abnormal DMN function may contribute to this characteristic. PMID:25076915

  11. Deficits in vision and visual attention associated with motor performance of very preterm/very low birth weight children.

    PubMed

    Geldof, Christiaan J A; van Hus, Janeline W P; Jeukens-Visser, Martine; Nollet, Frans; Kok, Joke H; Oosterlaan, Jaap; van Wassenaer-Leemhuis, Aleid G

    2016-01-01

    To extend understanding of impaired motor functioning of very preterm (VP)/very low birth weight (VLBW) children by investigating its relationship with visual attention, visual and visual-motor functioning. Motor functioning (Movement Assessment Battery for Children, MABC-2; Manual Dexterity, Aiming & Catching, and Balance component), as well as visual attention (attention network and visual search tests), vision (oculomotor, visual sensory and perceptive functioning), visual-motor integration (Beery Visual Motor Integration), and neurological status (Touwen examination) were comprehensively assessed in a sample of 106 5.5-year-old VP/VLBW children. Stepwise linear regression analyses were conducted to investigate multivariate associations between deficits in visual attention, oculomotor, visual sensory, perceptive and visual-motor integration functioning, abnormal neurological status, neonatal risk factors, and MABC-2 scores. Abnormal MABC-2 Total or component scores occurred in 23-36% of VP/VLBW children. Visual and visual-motor functioning accounted for 9-11% of variance in MABC-2 Total, Manual Dexterity and Balance scores. Visual perceptive deficits only were associated with Aiming & Catching. Abnormal neurological status accounted for an additional 19-30% of variance in MABC-2 Total, Manual Dexterity and Balance scores, and 5% of variance in Aiming & Catching, and neonatal risk factors for 3-6% of variance in MABC-2 Total, Manual Dexterity and Balance scores. Motor functioning is weakly associated with visual and visual-motor integration deficits and moderately associated with abnormal neurological status, indicating that motor performance reflects long term vulnerability following very preterm birth, and that visual deficits are of minor importance in understanding motor functioning of VP/VLBW children. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Visual Experience Enhances Infants' Use of Task-Relevant Information in an Action Task

    ERIC Educational Resources Information Center

    Wang, Su-hua; Kohne, Lisa

    2007-01-01

    Four experiments examined whether infants' use of task-relevant information in an action task could be facilitated by visual experience in the laboratory. Twelve- but not 9-month-old infants spontaneously used height information and chose an appropriate (taller) cover in search of a hidden tall toy. After watching examples of covering events in a…

  13. Overview of long-term field experiments in Germany - metadata visualization

    NASA Astrophysics Data System (ADS)

    Muqit Zoarder, Md Abdul; Heinrich, Uwe; Svoboda, Nikolai; Grosse, Meike; Hierold, Wilfried

    2017-04-01

    BonaRes ("soil as a sustainable resource for the bioeconomy") is conducting to collect data and metadata of agricultural long-term field experiments (LTFE) of Germany. It is funded by the German Federal Ministry of Education and Research (BMBF) under the umbrella of the National Research Strategy BioEconomy 2030. BonaRes consists of ten interdisciplinary research project consortia and the 'BonaRes - Centre for Soil Research'. BonaRes Data Centre is responsible for collecting all LTFE data and regarding metadata into an enterprise database upon higher level of security and visualization of the data and metadata through data portal. In the frame of the BonaRes project, we are compiling an overview of long-term field experiments in Germany that is based on a literature review, the results of the online survey and direct contacts with LTFE operators. Information about research topic, contact person, website, experiment setup and analyzed parameters are collected. Based on the collected LTFE data, an enterprise geodatabase is developed and a GIS-based web-information system about LTFE in Germany is also settled. Various aspects of the LTFE, like experiment type, land-use type, agricultural category and duration of experiment, are presented in thematic maps. This information system is dynamically linked to the database, which means changes in the data directly affect the presentation. An easy data searching option using LTFE name, -location or -operators and the dynamic layer selection ensure a user-friendly web application. Dispersion and visualization of the overlapping LTFE points on the overview map are also challenging and we make it automatized at very zoom level which is also a consistent part of this application. The application provides both, spatial location and meta-information of LTFEs, which is backed-up by an enterprise geodatabase, GIS server for hosting map services and Java script API for web application development.

  14. Abnormal center-periphery gradient in spatial attention in simultanagnosia.

    PubMed

    Balslev, Daniela; Odoj, Bartholomaeus; Rennig, Johannes; Karnath, Hans-Otto

    2014-12-01

    Patients suffering from simultanagnosia cannot perceive more than one object at a time. The underlying mechanism is incompletely understood. One hypothesis is that simultanagnosia reflects "tunnel vision," a constricted attention window around gaze, which precludes the grouping of individual objects. Although this idea has a long history in neuropsychology, the question whether the patients indeed have an abnormal attention gradient around the gaze has so far not been addressed. Here we tested this hypothesis in two simultanagnosia patients with bilateral parieto-occipital lesions and two control groups, with and without brain damage. We assessed the participants' ability to discriminate letters presented briefly at fixation with and without a peripheral distractor or in the visual periphery, with or without a foveal distractor. A constricted span of attention around gaze would predict an increased susceptibility to foveated versus peripheral distractors. Contrary to this prediction and unlike both control groups, the patients' ability to discriminate the target decreased more in the presence of peripheral compared with foveated distractors. Thus, the attentional spotlight in simultanagnosia does not fall on foveated objects as previously assumed, but rather abnormally highlights the periphery. Furthermore, we found the same center-periphery gradient in the patients' ability to recognize multiple objects. They detected multiple, but not single objects more accurately in the periphery than at fixation. These results suggest that an abnormal allocation of attention around the gaze can disrupt the grouping of individual objects into an integrated visual scene.

  15. Visual cortex in dementia with Lewy bodies: magnetic resonance imaging study

    PubMed Central

    Taylor, John-Paul; Firbank, Michael J.; He, Jiabao; Barnett, Nicola; Pearce, Sarah; Livingstone, Anthea; Vuong, Quoc; McKeith, Ian G.; O’Brien, John T.

    2012-01-01

    Background Visual hallucinations and visuoperceptual deficits are common in dementia with Lewy bodies, suggesting that cortical visual function may be abnormal. Aims To investigate: (1) cortical visual function using functional magnetic resonance imaging (fMRI); and (2) the nature and severity of perfusion deficits in visual areas using arterial spin labelling (ASL)-MRI. Method In total, 17 participants with dementia with Lewy bodies (DLB group) and 19 similarly aged controls were presented with simple visual stimuli (checkerboard, moving dots, and objects) during fMRI and subsequently underwent ASL-MRI (DLB group n = 15, control group n = 19). Results Functional activations were evident in visual areas in both the DLB and control groups in response to checkerboard and objects stimuli but reduced visual area V5/MT (middle temporal) activation occurred in the DLB group in response to motion stimuli. Posterior cortical perfusion deficits occurred in the DLB group, particularly in higher visual areas. Conclusions Higher visual areas, particularly occipito-parietal, appear abnormal in dementia with Lewy bodies, while there is a preservation of function in lower visual areas (V1 and V2/3). PMID:22500014

  16. The contributions of visual and central attention to visual working memory.

    PubMed

    Souza, Alessandra S; Oberauer, Klaus

    2017-10-01

    We investigated the role of two kinds of attention-visual and central attention-for the maintenance of visual representations in working memory (WM). In Experiment 1 we directed attention to individual items in WM by presenting cues during the retention interval of a continuous delayed-estimation task, and instructing participants to think of the cued items. Attending to items improved recall commensurate with the frequency with which items were attended (0, 1, or 2 times). Experiments 1 and 3 further tested which kind of attention-visual or central-was involved in WM maintenance. We assessed the dual-task costs of two types of distractor tasks, one tapping sustained visual attention and one tapping central attention. Only the central attention task yielded substantial dual-task costs, implying that central attention substantially contributes to maintenance of visual information in WM. Experiment 2 confirmed that the visual-attention distractor task was demanding enough to disrupt performance in a task relying on visual attention. We combined the visual-attention and the central-attention distractor tasks with a multiple object tracking (MOT) task. Distracting visual attention, but not central attention, impaired MOT performance. Jointly, the three experiments provide a double dissociation between visual and central attention, and between visual WM and visual object tracking: Whereas tracking multiple targets across the visual filed depends on visual attention, visual WM depends mostly on central attention.

  17. Retinal Layer Abnormalities as Biomarkers of Schizophrenia.

    PubMed

    Samani, Niraj N; Proudlock, Frank A; Siram, Vasantha; Suraweera, Chathurie; Hutchinson, Claire; Nelson, Christopher P; Al-Uzri, Mohammed; Gottlob, Irene

    2018-06-06

    Schizophrenia is associated with several brain deficits, as well as visual processing deficits, but clinically useful biomarkers are elusive. We hypothesized that retinal layer changes, noninvasively visualized using spectral-domain optical coherence tomography (SD-OCT), may represent a possible "window" to these abnormalities. A Leica EnvisuTM SD-OCT device was used to obtain high-resolution central foveal B-scans in both eyes of 35 patients with schizophrenia and 50 demographically matched controls. Manual retinal layer segmentation was performed to acquire individual and combined layer thickness measurements in 3 macular regions. Contrast sensitivity was measured at 3 spatial frequencies in a subgroup of each cohort. Differences were compared using adjusted linear models and significantly different layer measures in patients underwent Spearman Rank correlations with contrast sensitivity, quantified symptoms severity, disease duration, and antipsychotic medication dose. Total retinal and photoreceptor complex thickness was reduced in all regions in patients (P < .0001). Segmentation revealed consistent thinning of the outer nuclear layer (P < .001) and inner segment layer (P < .05), as well as a pattern of parafoveal ganglion cell changes. Low spatial frequency contrast sensitivity was reduced in patients (P = .002) and correlated with temporal parafoveal ganglion cell complex thinning (R = .48, P = .01). Negative symptom severity was inversely correlated with foveal photoreceptor complex thickness (R = -.54, P = .001) and outer nuclear layer thickness (R = -.47, P = .005). Our novel findings demonstrate considerable retinal layer abnormalities in schizophrenia that are related to clinical features and visual function. With time, SD-OCT could provide easily-measurable biomarkers to facilitate clinical assessment and further our understanding of the disease.

  18. Subclinical visual involvement in multiple sclerosis: a study by MRI, VEPs, frequency-doubling perimetry, standard perimetry, and contrast sensitivity.

    PubMed

    Sisto, Dario; Trojano, Maria; Vetrugno, Michele; Trabucco, Tiziana; Iliceto, Giovanni; Sborgia, Carlo

    2005-04-01

    To evaluate the effectiveness of visual evoked potentials (VEPs), frequency-doubling perimetry (FDP), standard achromatic perimetry (SAP), contrast sensitivity (CS) test, and magnetic resonance imaging (MRI), isolated or in combination, in detecting subclinical impairment of visual function in multiple sclerosis (MS). Twenty-two eyes of 11 patients affected by clinically definite MS, without a history of optic neuritis and asymptomatic for visual disturbances, underwent full ophthalmic examination and, in addition, VEPs, FDP, SAP, CS, and MRI. Abnormal results were taken to be as follows: for VEPs, a P100 latency >115 ms; for FDP, abnormal mean deviation (MD) or pattern SD (PSD); for SAP, abnormal MD or PSD; for CS, abnormal CS at one spatial frequency, at least; and for MRI, evidence of at least one demyelinating plaque along the visual pathway. VEPs showed abnormal results in 12 eyes (54.4%), FDP in 11 (50%), SAP in 14 (63.6%), CS in 17 (77.1%), and MRI in 16 (72.7%). In only two (9.1%) eyes of the same patient was no abnormality found. No single test detected all the abnormal eyes. Four (18.2%) eyes had pure optic nerve involvement and the remaining 16 (72.7%) had both pre- and postchiasmal involvement. In patients affected by clinically definite MS without history of optic neuritis and no visual symptoms, there is a large prevalence of visual pathway involvement that can be diagnosed only by performing multiple tests. The comparison of the tests is also useful to detect the presence of multiple lesions in the same patient.

  19. Visual impairment evaluation in 119 children with congenital Zika syndrome.

    PubMed

    Ventura, Liana O; Ventura, Camila V; Dias, Natália de C; Vilar, Isabelle G; Gois, Adriana L; Arantes, Tiago E; Fernandes, Luciene C; Chiang, Michael F; Miller, Marilyn T; Lawrence, Linda

    2018-06-01

    To assess visual impairment in a large sample of infants with congenital Zika syndrome (CZS) and to compare with a control group using the same assessment protocol. The study group was composed of infants with confirmed diagnosis of CZS. Controls were healthy infants matched for age, sex, and socioeconomic status. All infants underwent comprehensive ophthalmologic evaluation including visual acuity, visual function assessment, and visual developmental milestones. The CZS group included 119 infants; the control group, 85 infants. At examination, the mean age of the CZS group was 8.5 ± 1.2 months (range, 6-13 months); of the controls, 8.4 ± 1.8 months (range, 5-12 months; P = 0.598). Binocular Teller Acuity Card (TAC) testing was abnormal in 107 CZS infants and in 4 controls (89.9% versus 5% [P < 0.001]). In the study group, abnormal monocular TAC results were more frequent in eyes with funduscopic alterations (P = 0.008); however, 104 of 123 structurally normal eyes (84.6%) also presented abnormal TAC results. Binocular contrast sensitivity was reduced in 87 of 107 CZS infants and in 8 of 80 controls (81.3% versus 10% [P < 0.001]). The visual development milestones were less achieved by infants with CZS compared to controls (P < 0.001). Infants with CZS present with severe visual impairment. A protocol for assessment of the ocular findings, visual acuity, and visual developmental milestones tested against age-matched controls is suggested. Copyright © 2018 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  20. Sleep Physiology, Abnormal States, and Therapeutic Interventions

    PubMed Central

    Wickboldt, Alvah T.; Bowen, Alex F.; Kaye, Aaron J.; Kaye, Adam M.; Rivera Bueno, Franklin; Kaye, Alan D.

    2012-01-01

    Sleep is essential. Unfortunately, a significant portion of the population experiences altered sleep states that often result in a multitude of health-related issues. The regulation of sleep and sleep-wake cycles is an area of intense research, and many options for treatment are available. The following review summarizes the current understanding of normal and abnormal sleep-related conditions and the available treatment options. All clinicians managing patients must recommend appropriate therapeutic interventions for abnormal sleep states. Clinicians' solid understanding of sleep physiology, abnormal sleep states, and treatments will greatly benefit patients regardless of their disease process. PMID:22778676

  1. Recreational Physical Activity Experiences Among Guatemalan Families With Children With Visual Impairments.

    PubMed

    Columna, Luis; Fernández-Vivó, Margarita; Lieberman, Lauren; Arndt, Katrina

    2015-08-01

    Nationwide research indicates that children with visual impairment have limited participation in recreational and sport activities than their peers. This is due in part to the lack of recreational opportunities and facilities, as well as a lack of awareness by parents of how and where their children can participate. The purpose of the current study was to explore the experiences of Latino families of children with visual impairments living in Guatemala regarding physical recreation. Participants were Latino parents (N = 13) who have children with visual impairments recruited from a sport camp. Qualitative data were gathered through one-on-one interviews that were transcribed and analyzed through a constant comparative analysis. Participating Latino families who resided in Guatemala City participated at least once a month in low budget recreational activities with their children with visual impairments. Activities were mostly done in local surroundings and led mainly by their mother. Benefits identified by the participants related to relaxation, socialization, and sense of independence, with minimal mention of health related benefits. There is a need to disseminate information to the Latino community with children with visual impairments regarding the multiple benefits that arise from being involved in recreational physical activities.

  2. Layered Worlds: A Metaphor of Time, Visualizing the Experience of Alzheimer's.

    ERIC Educational Resources Information Center

    Grady, Ann M.

    This paper describes an exhibit, "Layered Worlds: The Look of Alzheimer's," which uses photography as the medium to interpret Alzheimer's disease visually. The goal was not to photograph the victims of the disease, but to interpret the experience of Alzheimer's for the patient, family members, and caregivers. The metaphor of layers was…

  3. Expert opinion on best practice guidelines and competency framework for visual screening in children.

    PubMed

    Lança, Carla

    2013-09-01

    Screening programs to detect visual abnormalities in children vary among countries. The aim of this study is to describe experts' perception of best practice guidelines and competency framework for visual screening in children. A qualitative focus group technique was applied during the Portuguese national orthoptic congress to obtain the perception of an expert panel of 5 orthoptists and 2 ophthalmologists with experience in visual screening for children (mean age 53.43 years, SD ± 9.40). The panel received in advance a script with the description of three tuning competencies dimensions (instrumental, systemic, and interpersonal) for visual screening. The session was recorded in video and audio. Qualitative data were analyzed using a categorical technique. According to experts' views, six tests (35.29%) have to be included in a visual screening: distance visual acuity test, cover test, bi-prism or 4/6(Δ) prism, fusion, ocular movements, and refraction. Screening should be performed according to the child age before and after 3 years of age (17.65%). The expert panel highlighted the influence of the professional experience in the application of a screening protocol (23.53%). They also showed concern about the false negatives control (23.53%). Instrumental competencies were the most cited (54.09%), followed by interpersonal (29.51%) and systemic (16.4%). Orthoptists should have professional experience before starting to apply a screening protocol. False negative results are a concern that has to be more thoroughly investigated. The proposed framework focuses on core competencies highlighted by the expert panel. Competencies programs could be important do develop better screening programs.

  4. Effect of binasal occlusion (BNO) on the visual-evoked potential (VEP) in mild traumatic brain injury (mTBI).

    PubMed

    Ciuffreda, Kenneth J; Yadav, Naveen K; Ludlam, Diana P

    2013-01-01

    The purpose of the experiment was to assess the effect of binasal occlusion (BNO) on the visually-evoked potential (VEP) in visually-normal (VN) individuals and in those with mild traumatic brain injury (mTBI) for whom BNO frequently reduces their primary symptoms related to abnormally-increased visual motion sensitivity (VMS). Subjects were comprised of asymptomatic VN adults (n = 10) and individuals with mTBI (n = 10) having the symptom of VMS. Conventional full-field VEP testing was employed under two conditions: without BNO and with opaque BNO which blocked regions on either side of the VEP test stimulus. Subjective impressions were also assessed. In VN, the mean VEP amplitude decreased significantly with BNO in all subjects. In contrast, in mTBI, the mean VEP amplitude increased significantly with BNO in all subjects. Latency was normal and unaffected in all cases. Repeat VEP testing in three subjects from each group revealed similar test-re-test findings. Visuomotor activities improved, with reduced symptoms, with BNO in the mTBI group. It is speculated that individuals with mTBI habitually attempt to suppress visual information in the near retinal periphery to reduce their abnormal VMS, with addition of the BNO negating the suppressive influence and thus producing a widespread disinhibition effect and resultant increase in VEP amplitude.

  5. Retinal adaptation abnormalities in primary open-angle glaucoma.

    PubMed

    Dul, Mitchell; Ennis, Robert; Radner, Shira; Lee, Barry; Zaidi, Qasim

    2015-01-22

    Dynamic color and brightness adaptation are crucial for visual functioning. The effects of glaucoma on retinal ganglion cells (RGCs) could compromise these functions. We have previously used slow dynamic changes of light at moderate intensities to measure the speed and magnitude of subtractive adaptation in RGCs. We used the same procedure to test if RGC abnormalities cause slower and weaker adaptation for patients with glaucoma when compared to age-similar controls. We assessed adaptation deficits in specific classes of RGCs by testing along the three cardinal color axes that isolate konio, parvo, and magno RGCs. For one eye each of 10 primary open-angle glaucoma patients and their age-similar controls, we measured the speed and magnitude of adapting to 1/32 Hz color modulations along the three cardinal axes, at central fixation and 8° superior, inferior, nasal, and temporal to fixation. In all 15 comparisons (5 locations × 3 color axes), average adaptation was slower and weaker for glaucoma patients than for controls. Adaptation developed slower at central targets than at 8° eccentricities for controls, but not for patients. Adaptation speed and magnitude differed between affected and control eyes even at retinal locations showing no visual field loss with clinical perimetry. Neural adaptation is weaker in glaucoma patients for all three classes of RGCs. Since adaptation abnormalities are manifested even at retinal locations not exhibiting a visual field loss, this novel form of assessment may offer a functional insight into glaucoma and an early diagnosis tool. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  6. Retinal Adaptation Abnormalities in Primary Open-Angle Glaucoma

    PubMed Central

    Dul, Mitchell; Ennis, Robert; Radner, Shira; Lee, Barry; Zaidi, Qasim

    2015-01-01

    Purpose. Dynamic color and brightness adaptation are crucial for visual functioning. The effects of glaucoma on retinal ganglion cells (RGCs) could compromise these functions. We have previously used slow dynamic changes of light at moderate intensities to measure the speed and magnitude of subtractive adaptation in RGCs. We used the same procedure to test if RGC abnormalities cause slower and weaker adaptation for patients with glaucoma when compared to age-similar controls. We assessed adaptation deficits in specific classes of RGCs by testing along the three cardinal color axes that isolate konio, parvo, and magno RGCs. Methods. For one eye each of 10 primary open-angle glaucoma patients and their age-similar controls, we measured the speed and magnitude of adapting to 1/32 Hz color modulations along the three cardinal axes, at central fixation and 8° superior, inferior, nasal, and temporal to fixation. Results. In all 15 comparisons (5 locations × 3 color axes), average adaptation was slower and weaker for glaucoma patients than for controls. Adaptation developed slower at central targets than at 8° eccentricities for controls, but not for patients. Adaptation speed and magnitude differed between affected and control eyes even at retinal locations showing no visual field loss with clinical perimetry. Conclusions. Neural adaptation is weaker in glaucoma patients for all three classes of RGCs. Since adaptation abnormalities are manifested even at retinal locations not exhibiting a visual field loss, this novel form of assessment may offer a functional insight into glaucoma and an early diagnosis tool. PMID:25613950

  7. [Electrocardiographic abnormalities in acute olanzapine poisonings].

    PubMed

    Ciszowski, Krzysztof; Sein Anand, Jacek

    2011-01-01

    Olanzapine is an atypical antipsychotic used for many years in the treatment of schizophrenia and bipolar disorder. Poisonings with this medicine can results with cardiotoxic effects in the form of ECG abnormalities. To evaluate the nature and incidence of electrocardiographic abnormalities in patients with acute olanzapine poisoning. 23 adult (mean age 38.4 +/- 15.5 years) patients with acute olanzapine poisoning, including 10 men (30.4 +/- 8.1 years) and 11 women (45.7 +/- 17.2 years), where 1 man and 1 woman were poisoned twice. The toxic serum level of olanzapine (above 100 ng/mL) was confirmed in each patient. Evaluation of electrocardiograms performed in patients in the first day of hospitalization with automatic measurement of durations of PQ, QRS and QTc and the identification of arrhythmias and conduction disorders on the basis of visual analysis of the ECG waveforms. Statistical analysis of the results using the methods of descriptive statistics. The mean durations of PQ, QRS and QTc in the study group were as follows: 135 +/- 23 ms, 91 +/- 12 ms, and 453 +/- 48 ms, respectively. The most common ECG abnormalities were prolonged QTc and supraventricular tachycardia (including sinus tachycardia) - each 22%; less common were ST-T changes (17%) and supraventricular premature complexes (9%), and only in individual cases (4%) ventricular premature complexes, bundle branch block, sinus bradycardia and atrial fibrillation were present. In the course of acute olanzapine poisonings: (1) prolonged QTc interval is quite common, but rarely leads to torsade de pointes tachycardia; (2) fast supraventricular rhythms are also common, but rarely cause irregular tachyarrhythmias, eg. atrial fibrillation; (3) conduction disorders (atrioventricular blocks, bundle branch blocks) are not typical abnormalities; (4) the observed ECG abnormalities emphasize the need of continuous ECG monitoring in these patients.

  8. Experiences of visually impaired students in higher education: Bodily perspectives on inclusive education.

    PubMed

    Lourens, Heidi; Swartz, Leslie

    Although previous literature sheds light on the experiences of visually impaired students on tertiary grounds, these studies failed to provide an embodied understanding of their lives. In-depth interviews with 15 visually impaired students at one university demonstrated the ways in which they experienced their disability and the built environment in their bodies. At the same time, lost, fearful, shameful and aching bodies revealed prevailing gaps in provision for disabled students. Through this research it becomes clear how the environment is acutely felt within fleshly worlds, while bodies do not fail to tell of disabling societal structures. Based on the bodily stories, we thus make recommendations to improve the lives of visually impaired students on tertiary campuses.

  9. Experiences of visually impaired students in higher education: Bodily perspectives on inclusive education

    PubMed Central

    Lourens, Heidi; Swartz, Leslie

    2016-01-01

    Although previous literature sheds light on the experiences of visually impaired students on tertiary grounds, these studies failed to provide an embodied understanding of their lives. In-depth interviews with 15 visually impaired students at one university demonstrated the ways in which they experienced their disability and the built environment in their bodies. At the same time, lost, fearful, shameful and aching bodies revealed prevailing gaps in provision for disabled students. Through this research it becomes clear how the environment is acutely felt within fleshly worlds, while bodies do not fail to tell of disabling societal structures. Based on the bodily stories, we thus make recommendations to improve the lives of visually impaired students on tertiary campuses. PMID:27917028

  10. Abnormal Microstructure of the Atrophic Thalamus in Preterm Survivors with Periventricular Leukomalacia

    PubMed Central

    Nagasunder, A.C.; Kinney, H.C.; Blüml, S.; Tavaré, C.J.; Rosser, T.; Gilles, F.H.; Nelson, M.D.; Panigrahy, A.

    2012-01-01

    BACKGROUND AND PURPOSE The neuroanatomic substrate of cognitive deficits in long-term survivors of prematurity with PVL is poorly understood. The thalamus is critically involved in cognition via extensive interconnections with the cerebral cortex. We hypothesized that the thalamus is atrophic (reduced in volume) in childhood survivors of prematurity with neuroimaging evidence of PVL and that the atrophy is associated with selective microstructural abnormalities within its subdivisions. MATERIALS AND METHODS We performed quantitative volumetric and DTI measurements of the thalamus in 17 children with neuroimaging evidence of PVL (mean postconceptional age, 5.6 ± 4.0 years) who were born prematurely and compared these with 74 term control children (5.7 ± 3.4 years). RESULTS The major findings were the following: 1) a significant reduction in the overall volume of the thalamus in patients with PVL compared with controls (P < .0001), which also correlated with the severity of PVL (P = .001); 2) significantly decreased FA (P = .003) and increased λ⊥ (P = .02) in the thalamus overall and increased axial, radial, and mean diffusivities in the pulvinar (P < .03), suggesting injury to afferent and efferent myelinated axons; and 3) a positive correlation of pulvinar abnormalities with those of the parieto-occipital white matter in periventricular leukomalacia, suggesting that the pulvinar abnormalities reflect secondary effects of damaged interconnections between the pulvinar and parieto-occipital cortices in the cognitive visual network. CONCLUSIONS There are volumetric and microstructural abnormalities of the thalamus in preterm children with PVL, very likely reflecting neuronal loss and myelinated axonal injury. The selective microstructural damage in the pulvinar very likely contributes to abnormal cognitive visual processing known to occur in such survivors. PMID:20930003

  11. Visual Prediction of Rover Slip: Learning Algorithms and Field Experiments

    DTIC Science & Technology

    2008-01-01

    DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE Visual Prediction of Rover Slip: Learning Algorithms and Field Experiments 5a...rover mobility [23, 78]. Remote slip prediction will enable safe traversals on large slopes covered with sand, drift material or loose crater ejecta...aqueous processes, e.g., mineral-rich out- crops which imply exposure to water [92] or putative lake formations or shorelines, layered deposits, etc

  12. Macular pigment and its contribution to visual performance and experience

    PubMed Central

    Loughman, James; Davison, Peter A.; Nolan, John M.; Akkali, Mukunda C.; Beatty, Stephen

    2010-01-01

    There is now a consensus, based on histological, biochemical and spectral absorption data, that the yellow colour observed at the macula lutea is a consequence of the selective accumulation of dietary xanthophylls in the central retina of the living eye. Scientific research continues to explore the function(s) of MP in the human retina, with two main hypotheses premised on its putative capacity to (1) protect the retina from (photo)-oxidative damage by means of its optical filtration and/or antioxidant properties, the so-called protective hypothesis and (2) influence the quality of visual performance by means of selective short wavelength light absorption prior to photoreceptor light capture, thereby attenuating the effects of chromatic aberration and light scatter, the so-called acuity and visibility hypotheses. The current epidemic of age-related macular degeneration has directed researchers to investigate the protective hypothesis of MP, while there has been a conspicuous lack of work designed to investigate the role of MP in visual performance. The aim of this review is to present and critically appraise the current literature germane to the contribution of MP, if any, to visual performance and experience.

  13. Four-Month-Old Infants' Visual Investigation of Cats and Dogs: Relations with Pet Experience and Attentional Strategy

    ERIC Educational Resources Information Center

    Kovack-Lesh, Kristine A.; McMurray, Bob; Oakes, Lisa M.

    2014-01-01

    We assessed the eye-movements of 4-month-old infants (N = 38) as they visually inspected pairs of images of cats or dogs. In general, infants who had previous experience with pets exhibited more sophisticated inspection than did infants without pet experience, both directing more visual attention to the informative head regions of the animals,…

  14. Mechanisms of recovery of visual function in adult amblyopia through a tailored action video game.

    PubMed

    Vedamurthy, Indu; Nahum, Mor; Bavelier, Daphne; Levi, Dennis M

    2015-02-26

    Amblyopia is a deficit in vision that arises from abnormal visual experience early in life. It was long thought to develop into a permanent deficit, unless properly treated before the end of the sensitive period for visual recovery. However, a number of studies now suggest that adults with long-standing amblyopia may at least partially recover visual acuity and stereopsis following perceptual training. Eliminating or reducing interocular suppression has been hypothesized to be at the root of these changes. Here we show that playing a novel dichoptic video game indeed results in reduced suppression, improved visual acuity and, in some cases, improved stereopsis. Our relatively large cohort of adults with amblyopia, allowed us, for the first time, to assess the link between visual function recovery and reduction in suppression. Surprisingly, no significant correlation was found between decreased suppression and improved visual function. This finding challenges the prevailing view and suggests that while dichoptic training improves visual acuity and stereopsis in adult amblyopia, reduced suppression is unlikely to be at the root of visual recovery. These results are discussed in the context of their implication on recovery of amblyopia in adults.

  15. Mechanisms of recovery of visual function in adult amblyopia through a tailored action video game

    PubMed Central

    Vedamurthy, Indu; Nahum, Mor; Bavelier, Daphne; Levi, Dennis M.

    2015-01-01

    Amblyopia is a deficit in vision that arises from abnormal visual experience early in life. It was long thought to develop into a permanent deficit, unless properly treated before the end of the sensitive period for visual recovery. However, a number of studies now suggest that adults with long-standing amblyopia may at least partially recover visual acuity and stereopsis following perceptual training. Eliminating or reducing interocular suppression has been hypothesized to be at the root of these changes. Here we show that playing a novel dichoptic video game indeed results in reduced suppression, improved visual acuity and, in some cases, improved stereopsis. Our relatively large cohort of adults with amblyopia, allowed us, for the first time, to assess the link between visual function recovery and reduction in suppression. Surprisingly, no significant correlation was found between decreased suppression and improved visual function. This finding challenges the prevailing view and suggests that while dichoptic training improves visual acuity and stereopsis in adult amblyopia, reduced suppression is unlikely to be at the root of visual recovery. These results are discussed in the context of their implication on recovery of amblyopia in adults. PMID:25719537

  16. Validation of the Preverbal Visual Assessment (PreViAs) questionnaire.

    PubMed

    García-Ormaechea, Inés; González, Inmaculada; Duplá, María; Andres, Eva; Pueyo, Victoria

    2014-10-01

    Visual cognitive integrative functions need to be evaluated by a behavioral assessment, which requires an experienced evaluator. The Preverbal Visual Assessment (PreViAs) questionnaire was designed to evaluate these functions, both in general pediatric population or in children with high risk of visual cognitive problems, through primary caregivers' answers. We aimed to validate the PreViAs questionnaire by comparing caregiver reports with results from a comprehensive clinical protocol. A total of 220 infants (<2 years old) were divided into two groups according to visual development, as determined by the clinical protocol. Their primary caregivers completed the PreViAs questionnaire, which consists of 30 questions related to one or more visual domains: visual attention, visual communication, visual-motor coordination, and visual processing. Questionnaire answers were compared with results of behavioral assessments performed by three pediatric ophthalmologists. Results of the clinical protocol classified 128 infants as having normal visual maturation, and 92 as having abnormal visual maturation. The specificity of PreViAs questionnaire was >80%, and sensitivity was 64%-79%. More than 80% of the infants were correctly classified, and test-retest reliability exceeded 0.9 for all domains. The PreViAs questionnaire is useful to detect abnormal visual maturation in infants from birth to 24months of age. It improves the anamnesis process in infants at risk of visual dysfunctions. Copyright © 2014. Published by Elsevier Ireland Ltd.

  17. Visually Guided Step Descent in Children with Williams Syndrome

    ERIC Educational Resources Information Center

    Cowie, Dorothy; Braddick, Oliver; Atkinson, Janette

    2012-01-01

    Individuals with Williams syndrome (WS) have impairments in visuospatial tasks and in manual visuomotor control, consistent with parietal and cerebellar abnormalities. Here we examined whether individuals with WS also have difficulties in visually controlling whole-body movements. We investigated visual control of stepping down at a change of…

  18. Multisensory integration and the concert experience: An overview of how visual stimuli can affect what we hear

    NASA Astrophysics Data System (ADS)

    Hyde, Jerald R.

    2004-05-01

    It is clear to those who ``listen'' to concert halls and evaluate their degree of acoustical success that it is quite difficult to separate the acoustical response at a given seat from the multi-modal perception of the whole event. Objective concert hall data have been collected for the purpose of finding a link with their related subjective evaluation and ultimately with the architectural correlates which produce the sound field. This exercise, while important, tends to miss the point that a concert or opera event utilizes all the senses of which the sound field and visual stimuli are both major contributors to the experience. Objective acoustical factors point to visual input as being significant in the perception of ``acoustical intimacy'' and with the perception of loudness versus distance in large halls. This paper will review the evidence of visual input as a factor in what we ``hear'' and introduce concepts of perceptual constancy, distance perception, static and dynamic visual stimuli, and the general process of the psychology of the integrated experience. A survey of acousticians on their opinions about the auditory-visual aspects of the concert hall experience will be presented. [Work supported in part from the Veneklasen Research Foundation and Veneklasen Associates.

  19. M-Stream Deficits and Reading-Related Visual Processes in Developmental Dyslexia

    ERIC Educational Resources Information Center

    Boden, Catherine; Giaschi, Deborah

    2007-01-01

    Some visual processing deficits in developmental dyslexia have been attributed to abnormalities in the subcortical M stream and/or the cortical dorsal stream of the visual pathways. The nature of the relationship between these visual deficits and reading is unknown. The purpose of the present article was to characterize reading-related perceptual…

  20. Visual dysfunction in Parkinson’s disease

    PubMed Central

    Weil, Rimona S.; Schrag, Anette E.; Warren, Jason D.; Crutch, Sebastian J.; Lees, Andrew J.; Morris, Huw R.

    2016-01-01

    Patients with Parkinson’s disease have a number of specific visual disturbances. These include changes in colour vision and contrast sensitivity and difficulties with complex visual tasks such as mental rotation and emotion recognition. We review changes in visual function at each stage of visual processing from retinal deficits, including contrast sensitivity and colour vision deficits to higher cortical processing impairments such as object and motion processing and neglect. We consider changes in visual function in patients with common Parkinson’s disease-associated genetic mutations including GBA and LRRK2. We discuss the association between visual deficits and clinical features of Parkinson’s disease such as rapid eye movement sleep behavioural disorder and the postural instability and gait disorder phenotype. We review the link between abnormal visual function and visual hallucinations, considering current models for mechanisms of visual hallucinations. Finally, we discuss the role of visuo-perceptual testing as a biomarker of disease and predictor of dementia in Parkinson’s disease. PMID:27412389

  1. Illusory conjunctions and perceptual grouping in a visual search task in schizophrenia.

    PubMed

    Carr, V J; Dewis, S A; Lewin, T J

    1998-07-27

    This report describes part of a series of experiments, conducted within the framework of feature integration theory, to determine whether patients with schizophrenia show deficits in preattentive processing. Thirty subjects with a DSM-III-R diagnosis of schizophrenia and 30 age-, gender-, and education-matched normal control subjects completed two computerized experimental tasks, a visual search task assessing the frequency of illusory conjunctions (i.e. false perceptions) under conditions of divided attention (Experiment 3) and a task which examined the effects of perceptual grouping on illusory conjunctions (Experiment 4). We also assessed current symptomatology and its relationship to task performance. Contrary to our hypotheses, schizophrenia subjects did not show higher rates of illusory conjunctions, and the influence of perceptual grouping on the frequency of illusory conjunctions was similar for schizophrenia and control subjects. Nonetheless, specific predictions from feature integration theory about the impact of different target types (Experiment 3) and perceptual groups (Experiment 4) on the likelihood of forming an illusory conjunction were strongly supported, thereby confirming the integrity of the experimental procedures. Overall, these studies revealed no firm evidence that schizophrenia is associated with a preattentive abnormality in visual search using stimuli that differ on the basis of physical characteristics.

  2. 3D Data Mapping and Real-Time Experiment Control and Visualization in Brain Slices.

    PubMed

    Navarro, Marco A; Hibbard, Jaime V K; Miller, Michael E; Nivin, Tyler W; Milescu, Lorin S

    2015-10-20

    Here, we propose two basic concepts that can streamline electrophysiology and imaging experiments in brain slices and enhance data collection and analysis. The first idea is to interface the experiment with a software environment that provides a 3D scene viewer in which the experimental rig, the brain slice, and the recorded data are represented to scale. Within the 3D scene viewer, the user can visualize a live image of the sample and 3D renderings of the recording electrodes with real-time position feedback. Furthermore, the user can control the instruments and visualize their status in real time. The second idea is to integrate multiple types of experimental data into a spatial and temporal map of the brain slice. These data may include low-magnification maps of the entire brain slice, for spatial context, or any other type of high-resolution structural and functional image, together with time-resolved electrical and optical signals. The entire data collection can be visualized within the 3D scene viewer. These concepts can be applied to any other type of experiment in which high-resolution data are recorded within a larger sample at different spatial and temporal coordinates. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  3. Improving the User Experience of Finding and Visualizing Oceanographic Data

    NASA Astrophysics Data System (ADS)

    Rauch, S.; Allison, M. D.; Groman, R. C.; Chandler, C. L.; Galvarino, C.; Gegg, S. R.; Kinkade, D.; Shepherd, A.; Wiebe, P. H.; Glover, D. M.

    2013-12-01

    Searching for and locating data of interest can be a challenge to researchers as increasing volumes of data are made available online through various data centers, repositories, and archives. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) is keenly aware of this challenge and, as a result, has implemented features and technologies aimed at improving data discovery and enhancing the user experience. BCO-DMO was created in 2006 to manage and publish data from research projects funded by the Division of Ocean Sciences (OCE) Biological and Chemical Oceanography Sections and the Division of Polar Programs (PLR) Antarctic Sciences Organisms and Ecosystems Program (ANT) of the US National Science Foundation (NSF). The BCO-DMO text-based and geospatial-based data access systems provide users with tools to search, filter, and visualize data in order to efficiently find data of interest. The geospatial interface, developed using a suite of open-source software (including MapServer [1], OpenLayers [2], ExtJS [3], and MySQL [4]), allows users to search and filter/subset metadata based on program, project, or deployment, or by using a simple word search. The map responds based on user selections, presents options that allow the user to choose specific data parameters (e.g., a species or an individual drifter), and presents further options for visualizing those data on the map or in "quick-view" plots. The data managed and made available by BCO-DMO are very heterogeneous in nature, from in-situ biogeochemical, ecological, and physical data, to controlled laboratory experiments. Due to the heterogeneity of the data types, a 'one size fits all' approach to visualization cannot be applied. Datasets are visualized in a way that will best allow users to assess fitness for purpose. An advanced geospatial interface, which contains a semantically-enabled faceted search [5], is also available. These search facets are highly interactive and responsive, allowing

  4. Health services experiences of parents of recently diagnosed visually impaired children

    PubMed Central

    Rahi, J S; Manaras, I; Tuomainen, H; Lewando Hundt, G

    2005-01-01

    Aim: To investigate the health service experiences and needs of parents in the period around diagnosis of ophthalmic disorders in their children. Methods: Parents of children newly diagnosed with visual impairment and/or ophthalmic disorders at a tertiary level hospital in London participated in a questionnaire survey, using standard instruments, followed by in-depth individual interviews, to elicit their views about the processes of care, their overall level of satisfaction, and their unmet needs. Results: 67% (147) of eligible families (135 mothers, 76 fathers) participated. Overall satisfaction with care was high, being greater among parents of children with milder visual loss or isolated ophthalmic disorders than those with more severe visual loss or multiple impairments. Nevertheless, parents’ reported greatest need was the provision of general information, including about their child’s ophthalmic disorder and educational and social services and support. Mothers reported greater information needs than fathers, as did white parents compared to those from ethnic minorities. White parents also regarded the processes of care to be less comprehensive and coordinated, as well as less enabling, than did parents from ethnic minorities. Conclusions: Although parents reported high overall satisfaction with services, improving the medium, content, and scope of general information provided by professionals to parents of visually impaired children emerges as a priority. Equitable planning and provision of health services for families of children with visual impairment needs to take into account that informational and other needs vary by whether the parent is the primary carer or not and their ethnicity, as well as by the severity and complexity of their child’s visual loss. PMID:15665355

  5. A habituation based approach for detection of visual changes in surveillance camera

    NASA Astrophysics Data System (ADS)

    Sha'abani, M. N. A. H.; Adan, N. F.; Sabani, M. S. M.; Abdullah, F.; Nadira, J. H. S.; Yasin, M. S. M.

    2017-09-01

    This paper investigates a habituation based approach in detecting visual changes using video surveillance systems in a passive environment. Various techniques have been introduced for dynamic environment such as motion detection, object classification and behaviour analysis. However, in a passive environment, most of the scenes recorded by the surveillance system are normal. Therefore, implementing a complex analysis all the time in the passive environment resulting on computationally expensive, especially when using a high video resolution. Thus, a mechanism of attention is required, where the system only responds to an abnormal event. This paper proposed a novelty detection mechanism in detecting visual changes and a habituation based approach to measure the level of novelty. The objective of the paper is to investigate the feasibility of the habituation based approach in detecting visual changes. Experiment results show that the approach are able to accurately detect the presence of novelty as deviations from the learned knowledge.

  6. The influence of anaesthetists' experience on workload, performance and visual attention during simulated critical incidents.

    PubMed

    Schulz, Christian M; Schneider, Erich; Kohlbecher, Stefan; Hapfelmeier, Alexander; Heuser, Fabian; Wagner, Klaus J; Kochs, Eberhard F; Schneider, Gerhard

    2014-10-01

    Development of accurate Situation Awareness (SA) depends on experience and may be impaired during excessive workload. In order to gain adequate SA for decision making and performance, anaesthetists need to distribute visual attention effectively. Therefore, we hypothesized that in more experienced anaesthetists performance is better and increase of physiological workload is less during critical incidents. Additionally, we investigated the relation between physiological workload indicators and distribution of visual attention. In fifteen anaesthetists, the increase of pupil size and heart rate was assessed in course of a simulated critical incident. Simulator log files were used for performance assessment. An eye-tracking device (EyeSeeCam) provided data about the anaesthetists' distribution of visual attention. Performance was assessed as time until definitive treatment. T tests and multivariate generalized linear models (MANOVA) were used for retrospective statistical analysis. Mean pupil diameter increase was 8.1% (SD ± 4.3) in the less experienced and 15.8% (±10.4) in the more experienced subjects (p = 0.191). Mean heart rate increase was 10.2% (±6.7) and 10.5% (±8.3, p = 0.956), respectively. Performance did not depend on experience. Pupil diameter and heart rate increases were associated with a shift of visual attention from monitoring towards manual tasks (not significant). For the first time, the following four variables were assessed simultaneously: physiological workload indicators, performance, experience, and distribution of visual attention between "monitoring" and "manual" tasks. However, we were unable to detect significant interactions between these variables. This experimental model could prove valuable in the investigation of gaining and maintaining SA in the operation theatre.

  7. Visual-vestibular processing deficits in mild traumatic brain injury.

    PubMed

    Wright, W G; Tierney, R T; McDevitt, J

    2017-01-01

    The search for reliable and valid signs and symptoms of mild traumatic brain injury (mTBI), commonly synonymous with concussion, has lead to a growing body of evidence that individuals with long-lasting, unremitting impairments often experience visual and vestibular symptoms, such as dizziness, postural and gait disturbances. Investigate the role of visual-vestibular processing deficits following concussion. A number of clinically accepted vestibular, oculomotor, and balance assessments as well as a novel virtual reality (VR)-based balance assessment device were used to assess adults with post-acute concussion (n = 14) in comparison to a healthy age-matched cohort (n = 58). Significant between-group differences were found with the VR-based balance device (p = 0.001), with dynamic visual motion emerging as the most discriminating balance condition. The symptom reports collected after performing the oculomotor and vestibular tests: rapid alternating horizontal eye saccades, optokinetic stimulation, and gaze stabilization, were all sensitive to health status (p < 0.05), despite the absence of oculomotor abnormalities being observed, except for near-point convergence. The BESS, King-Devick, and Dynamic Visual Acuity tests did not detect between-group differences. Postural and visual-vestibular tasks most closely linked to spatial and self-motion perception had the greatest discriminatory outcomes. The current findings suggest that mesencephalic and parieto-occipital centers and pathways may be involved in concussion.

  8. Postural abnormalities and contraversive pushing following right hemisphere brain damage.

    PubMed

    Lafosse, C; Kerckhofs, E; Vereeck, L; Troch, M; Van Hoydonck, G; Moeremans, M; Sneyers, C; Broeckx, J; Dereymaeker, L

    2007-06-01

    We investigated the presence of postural abnormalities in a consecutive sample of stroke patients, with either left or right brain damage, in relation to their perceived body position in space. The presence or absence of posture-related symptoms was judged by two trained therapists and subsequently analysed by hierarchical classes analysis (HICLAS). The subject classes resulting from the HICLAS model were further validated with respect to posture-related measurements, such as centre of gravity position and head position, as well as measurements related to the postural body scheme, such as the perception of postural and visual verticality. The results of the classification analysis clearly demonstrated a relation between the presence of right brain damage and abnormalities in body geometry. The HICLAS model revealed three classes of subjects: The first class contained almost all the patients without neglect and without any signs of contraversive pushing. They were mainly characterised by a normal body axis in any position. The second class were all neglect patients but predominantly without any contraversive pushing. The third class contained right brain damaged patients, all showing neglect and mostly exhibiting contraversive pushing. The patients in the third class showed a clear resistance to bringing the weight over to the ipsilesional side when the therapist attempted to make the subject achieve a vertical posture across the midline. The clear correspondence between abnormalities of the observed body geometry and the tilt of the subjective postural and visual vertical suggests that a patient's postural body geometry is characterised by leaning towards the side of space where he/she feels aligned with an altered postural body scheme. The presence of contraversive pushing after right brain damage points in to a spatial higher-order processing deficit underlying the higher frequency and severity of the axial postural abnormalities found after right brain lesions.

  9. Efficient visualization of high-throughput targeted proteomics experiments: TAPIR.

    PubMed

    Röst, Hannes L; Rosenberger, George; Aebersold, Ruedi; Malmström, Lars

    2015-07-15

    Targeted mass spectrometry comprises a set of powerful methods to obtain accurate and consistent protein quantification in complex samples. To fully exploit these techniques, a cross-platform and open-source software stack based on standardized data exchange formats is required. We present TAPIR, a fast and efficient Python visualization software for chromatograms and peaks identified in targeted proteomics experiments. The input formats are open, community-driven standardized data formats (mzML for raw data storage and TraML encoding the hierarchical relationships between transitions, peptides and proteins). TAPIR is scalable to proteome-wide targeted proteomics studies (as enabled by SWATH-MS), allowing researchers to visualize high-throughput datasets. The framework integrates well with existing automated analysis pipelines and can be extended beyond targeted proteomics to other types of analyses. TAPIR is available for all computing platforms under the 3-clause BSD license at https://github.com/msproteomicstools/msproteomicstools. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. The 1980 and 1981 accident experience of civil airmen with selected visual pathology.

    DOT National Transportation Integrated Search

    1983-07-01

    In studies of the 1974-76 accident experience of U.S. general aviation pilots with static physical defects, all the significantly increased rates and ratios were for visual defect categories--blindness, or absence of either eye, deficient distant vis...

  11. Abnormal global and local event detection in compressive sensing domain

    NASA Astrophysics Data System (ADS)

    Wang, Tian; Qiao, Meina; Chen, Jie; Wang, Chuanyun; Zhang, Wenjia; Snoussi, Hichem

    2018-05-01

    Abnormal event detection, also known as anomaly detection, is one challenging task in security video surveillance. It is important to develop effective and robust movement representation models for global and local abnormal event detection to fight against factors such as occlusion and illumination change. In this paper, a new algorithm is proposed. It can locate the abnormal events on one frame, and detect the global abnormal frame. The proposed algorithm employs a sparse measurement matrix designed to represent the movement feature based on optical flow efficiently. Then, the abnormal detection mission is constructed as a one-class classification task via merely learning from the training normal samples. Experiments demonstrate that our algorithm performs well on the benchmark abnormal detection datasets against state-of-the-art methods.

  12. Words, shape, visual search and visual working memory in 3-year-old children.

    PubMed

    Vales, Catarina; Smith, Linda B

    2015-01-01

    Do words cue children's visual attention, and if so, what are the relevant mechanisms? Across four experiments, 3-year-old children (N = 163) were tested in visual search tasks in which targets were cued with only a visual preview versus a visual preview and a spoken name. The experiments were designed to determine whether labels facilitated search times and to examine one route through which labels could have their effect: By influencing the visual working memory representation of the target. The targets and distractors were pictures of instances of basic-level known categories and the labels were the common name for the target category. We predicted that the label would enhance the visual working memory representation of the target object, guiding attention to objects that better matched the target representation. Experiments 1 and 2 used conjunctive search tasks, and Experiment 3 varied shape discriminability between targets and distractors. Experiment 4 compared the effects of labels to repeated presentations of the visual target, which should also influence the working memory representation of the target. The overall pattern fits contemporary theories of how the contents of visual working memory interact with visual search and attention, and shows that even in very young children heard words affect the processing of visual information. © 2014 John Wiley & Sons Ltd.

  13. 'My brain couldn't move from planning a birth to planning a funeral': a qualitative study of parents' experiences of decisions after ending a pregnancy for fetal abnormality.

    PubMed

    Hunt, Kate; France, Emma; Ziebland, Sue; Field, Kate; Wyke, Sally

    2009-08-01

    With increasing technology for screening and diagnostic testing for fetal abnormality in pregnancy, many more pregnant women and couples are faced with the decision to terminate a pregnancy often after receiving diagnostic test results in the second or third trimester of pregnancy. Whilst there is extensive research on people's experience of diagnostic testing and decision-making, there has been less research on people's experiences of decisions they face immediately following their termination. To describe the experiences of (often unanticipated) decisions that people face in the immediate aftermath of ending a pregnancy following diagnosis of serious fetal abnormality. Secondary analysis of narrative qualitative interview data. Participants were recruited throughout the United Kingdom (UK) and interviewed between 2004 and 2006. 38 individual mothers, 10 individual fathers and 10 couples who ended a pregnancy following diagnosis of fetal abnormality. Parents who had experienced the ending of a pregnancy following diagnosis of fetal abnormality described their experiences, and often distress, of facing painful decisions consequent upon their decision to terminate the pregnancy. What was striking from their accounts was their sense of being unprepared for these decisions. Often they suggested that they had received no information or forewarning of the 'choices' they would have to make, although information designed specifically for people in this situation is available in the UK. Many of the decisions that people face in the immediate aftermath of a termination for fetal abnormality are upsetting, and in some circumstances more so because they are not anticipated. Often parents report not receiving information which could be helpful until after these decisions have been made. Health professionals face difficult choices about what issues to raise with patients at this sensitive time, and the optimum time to inform patients of the extra decisions they will face. More

  14. Pareidolias: complex visual illusions in dementia with Lewy bodies.

    PubMed

    Uchiyama, Makoto; Nishio, Yoshiyuki; Yokoi, Kayoko; Hirayama, Kazumi; Imamura, Toru; Shimomura, Tatsuo; Mori, Etsuro

    2012-08-01

    Patients rarely experience visual hallucinations while being observed by clinicians. Therefore, instruments to detect visual hallucinations directly from patients are needed. Pareidolias, which are complex visual illusions involving ambiguous forms that are perceived as meaningful objects, are analogous to visual hallucinations and have the potential to be a surrogate indicator of visual hallucinations. In this study, we explored the clinical utility of a newly developed instrument for evoking pareidolic illusions, the Pareidolia test, in patients with dementia with Lewy bodies-one of the most common causes of visual hallucinations in the elderly. Thirty-four patients with dementia with Lewy bodies, 34 patients with Alzheimer's disease and 26 healthy controls were given the Pareidolia test. Patients with dementia with Lewy bodies produced a much greater number of pareidolic illusions compared with those with Alzheimer's disease or controls. A receiver operating characteristic analysis demonstrated that the number of pareidolias differentiated dementia with Lewy bodies from Alzheimer's disease with a sensitivity of 100% and a specificity of 88%. Full-length figures and faces of people and animals accounted for >80% of the contents of pareidolias. Pareidolias were observed in patients with dementia with Lewy bodies who had visual hallucinations as well as those who did not have visual hallucinations, suggesting that pareidolias do not reflect visual hallucinations themselves but may reflect susceptibility to visual hallucinations. A sub-analysis of patients with dementia with Lewy bodies who were or were not treated with donepzil demonstrated that the numbers of pareidolias were correlated with visuoperceptual abilities in the former and with indices of hallucinations and delusional misidentifications in the latter. Arousal and attentional deficits mediated by abnormal cholinergic mechanisms and visuoperceptual dysfunctions are likely to contribute to the development

  15. Pareidolias: complex visual illusions in dementia with Lewy bodies

    PubMed Central

    Uchiyama, Makoto; Yokoi, Kayoko; Hirayama, Kazumi; Imamura, Toru; Shimomura, Tatsuo; Mori, Etsuro

    2012-01-01

    Patients rarely experience visual hallucinations while being observed by clinicians. Therefore, instruments to detect visual hallucinations directly from patients are needed. Pareidolias, which are complex visual illusions involving ambiguous forms that are perceived as meaningful objects, are analogous to visual hallucinations and have the potential to be a surrogate indicator of visual hallucinations. In this study, we explored the clinical utility of a newly developed instrument for evoking pareidolic illusions, the Pareidolia test, in patients with dementia with Lewy bodies—one of the most common causes of visual hallucinations in the elderly. Thirty-four patients with dementia with Lewy bodies, 34 patients with Alzheimer’s disease and 26 healthy controls were given the Pareidolia test. Patients with dementia with Lewy bodies produced a much greater number of pareidolic illusions compared with those with Alzheimer’s disease or controls. A receiver operating characteristic analysis demonstrated that the number of pareidolias differentiated dementia with Lewy bodies from Alzheimer’s disease with a sensitivity of 100% and a specificity of 88%. Full-length figures and faces of people and animals accounted for >80% of the contents of pareidolias. Pareidolias were observed in patients with dementia with Lewy bodies who had visual hallucinations as well as those who did not have visual hallucinations, suggesting that pareidolias do not reflect visual hallucinations themselves but may reflect susceptibility to visual hallucinations. A sub-analysis of patients with dementia with Lewy bodies who were or were not treated with donepzil demonstrated that the numbers of pareidolias were correlated with visuoperceptual abilities in the former and with indices of hallucinations and delusional misidentifications in the latter. Arousal and attentional deficits mediated by abnormal cholinergic mechanisms and visuoperceptual dysfunctions are likely to contribute to the

  16. Cognitive processing of visual images in migraine populations in between headache attacks.

    PubMed

    Mickleborough, Marla J S; Chapman, Christine M; Toma, Andreea S; Handy, Todd C

    2014-09-25

    People with migraine headache have altered interictal visual sensory-level processing in between headache attacks. Here we examined the extent to which these migraine abnormalities may extend into higher visual processing such as implicit evaluative analysis of visual images in between migraine events. Specifically, we asked two groups of participants--migraineurs (N=29) and non-migraine controls (N=29)--to view a set of unfamiliar commercial logos in the context of a target identification task as the brain electrical responses to these objects were recorded via event-related potentials (ERPs). Following this task, participants individually identified those logos that they most liked or disliked. We applied a between-groups comparison of how ERP responses to logos varied as a function of hedonic evaluation. Our results suggest migraineurs have abnormal implicit evaluative processing of visual stimuli. Specifically, migraineurs lacked a bias for disliked logos found in control subjects, as measured via a late positive potential (LPP) ERP component. These results suggest post-sensory consequences of migraine in between headache events, specifically abnormal cognitive evaluative processing with a lack of normal categorical hedonic evaluation. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Influence of rotating shift work on visual reaction time and visual evoked potential.

    PubMed

    R V, Hemamalini; N, Krishnamurthy; A, Saravanan

    2014-10-01

    The present day life style is changing the circadian rhythm of the body especially in rotating night shift workers. The impact of this prolongs their reaction time. Night shift also interferes with the circadian variation of pupil size which may affect the visual evoked potential. To compare the visual reaction time, visual evoked potential (VEP) in rotating night shift workers & day workers and also to correlate the changes in visual reaction time with visual evoked potential. Forty healthy male security guards & staff (25 - 35 y) who did rotating night shifts at least for six months & 40 d workers (25 - 35 y) who did not do night shift in last two years were involved in the study. Visual reaction time and the latency & amplitude of VEP were recorded. Kolmogorov- Smirnov test for normalcy showed the latencies & amplitude of VEP to be normally distributed. Student's unpaired t test showed significant difference (p<0.05) in the visual time and in the latencies of VEP between night shift & day workers. There was no significant difference in the amplitude of VEP. Night shift workers who are prone to circadian rhythm alteration will have prolonged visual reaction time & visual evoked potential abnormalities. Implementation of Bright Light Therapy would be beneficial to the night shift worker.

  18. Spreading Photoparoxysmal EEG Response is Associated with an Abnormal Cortical Excitability Pattern

    ERIC Educational Resources Information Center

    Siniatchkin, Michael; Groppa, Sergey; Jerosch, Bettina; Muhle, Hiltrud; Kurth, Christoph; Shepherd, Alex J.; Siebner, Hartwig; Stephani, Ulrich

    2007-01-01

    Photosensitivity or photoparoxysmal response (PPR) is a highly heritable electroencephalographic trait characterized by an abnormal cortical response to intermittent photic stimulation (IPS). In PPR-positive individuals, IPS induces spikes, spike-waves or intermittent slow waves. The PPR may be restricted to posterior visual areas (i.e. local PPR…

  19. Eye movement abnormalities in hermansky-pudlak syndrome.

    PubMed

    Gradstein, Libe; FitzGibbon, Edmond J; Tsilou, Ekaterini T; Rubin, Benjamin I; Huizing, Marjan; Gahl, William A

    2005-08-01

    Hermansky-Pudlak Syndrome (HPS) is a type of oculocutaneous albinism associated with a bleeding diathesis and pulmonary fibrosis. Although it is known that patients with HPS exhibit nystagmus, the nature of these abnormal eye movements has not been studied. Twenty-seven patients with HPS, diagnosed by platelet morphology and genetic analysis, underwent a systemic evaluation and complete eye examination. Twenty-five had eye movement recordings using magnetic search coil, infrared, or video oculography. All patients had iris transillumination, foveal hypoplasia, and variable hypopigmentation in skin and eyes. All had bleeding tendencies, and 2 reported excessive bleeding during strabismus surgery. Nine patients had pulmonary fibrosis. Visual acuities ranged from 20/20- to 20/320. Twenty patients had strabismus despite 6 having strabismus surgery previously. Ocular oscillations consistent with congenital nystagmus (CN) were clinically evident in 24 of 27 patients, and half showed periodic alternating nystagmus. In 3 patients without CN, eye movement recordings revealed minimal end-gaze nystagmus, square-wave jerks, drift during fixation and saccades, and low-gain pursuit. These patients had melanin in the posterior pole and better visual acuities than the others (P = 0.002). Most patients with HPS have CN, and many have periodic alternating nystagmus. Some have subtle eye movement abnormalities without clinically evident nystagmus, which can obscure the diagnosis, especially if hypopigmentation is mild. Absence of clinical nystagmus in a child with HPS suggests good vision. Patients with albinism, especially before surgery, should be evaluated for HPS to prevent life-threatening complications.

  20. Levetiracetam reduces abnormal network activations in temporal lobe epilepsy.

    PubMed

    Wandschneider, Britta; Stretton, Jason; Sidhu, Meneka; Centeno, Maria; Kozák, Lajos R; Symms, Mark; Thompson, Pamela J; Duncan, John S; Koepp, Matthias J

    2014-10-21

    We used functional MRI (fMRI) and a left-lateralizing verbal and a right-lateralizing visual-spatial working memory (WM) paradigm to investigate the effects of levetiracetam (LEV) on cognitive network activations in patients with drug-resistant temporal lobe epilepsy (TLE). In a retrospective study, we compared task-related fMRI activations and deactivations in 53 patients with left and 54 patients with right TLE treated with (59) or without (48) LEV. In patients on LEV, activation patterns were correlated with the daily LEV dose. We isolated task- and syndrome-specific effects. Patients on LEV showed normalization of functional network deactivations in the right temporal lobe in right TLE during the right-lateralizing visual-spatial task and in the left temporal lobe in left TLE during the verbal task. In a post hoc analysis, a significant dose-dependent effect was demonstrated in right TLE during the visual-spatial WM task: the lower the LEV dose, the greater the abnormal right hippocampal activation. At a less stringent threshold (p < 0.05, uncorrected for multiple comparisons), a similar dose effect was observed in left TLE during the verbal task: both hippocampi were more abnormally activated in patients with lower doses, but more prominently on the left. Our findings suggest that LEV is associated with restoration of normal activation patterns. Longitudinal studies are necessary to establish whether the neural patterns translate to drug response. This study provides Class III evidence that in patients with drug-resistant TLE, levetiracetam has a dose-dependent facilitation of deactivation of mesial temporal structures. © 2014 American Academy of Neurology.

  1. Visual information processing of faces in body dysmorphic disorder.

    PubMed

    Feusner, Jamie D; Townsend, Jennifer; Bystritsky, Alexander; Bookheimer, Susan

    2007-12-01

    Body dysmorphic disorder (BDD) is a severe psychiatric condition in which individuals are preoccupied with perceived appearance defects. Clinical observation suggests that patients with BDD focus on details of their appearance at the expense of configural elements. This study examines abnormalities in visual information processing in BDD that may underlie clinical symptoms. To determine whether patients with BDD have abnormal patterns of brain activation when visually processing others' faces with high, low, or normal spatial frequency information. Case-control study. University hospital. Twelve right-handed, medication-free subjects with BDD and 13 control subjects matched by age, sex, and educational achievement. Intervention Functional magnetic resonance imaging while performing matching tasks of face stimuli. Stimuli were neutral-expression photographs of others' faces that were unaltered, altered to include only high spatial frequency visual information, or altered to include only low spatial frequency visual information. Blood oxygen level-dependent functional magnetic resonance imaging signal changes in the BDD and control groups during tasks with each stimulus type. Subjects with BDD showed greater left hemisphere activity relative to controls, particularly in lateral prefrontal cortex and lateral temporal lobe regions for all face tasks (and dorsal anterior cingulate activity for the low spatial frequency task). Controls recruited left-sided prefrontal and dorsal anterior cingulate activity only for the high spatial frequency task. Subjects with BDD demonstrate fundamental differences from controls in visually processing others' faces. The predominance of left-sided activity for low spatial frequency and normal faces suggests detail encoding and analysis rather than holistic processing, a pattern evident in controls only for high spatial frequency faces. These abnormalities may be associated with apparent perceptual distortions in patients with BDD. The

  2. Visual functions of commercial drivers in relation to road accidents in Nigeria

    PubMed Central

    Oladehinde, M. K.; Adeoye, A. O.; Adegbehingbe, B. O.; Onakoya, A. O.

    2007-01-01

    Objective: To determine the effects of the visual functions on the occurrence of road traffic accidents (RTA) amongst commercial drivers in Ife central local government area (LGA) of Osun state of Nigeria. Design: A cross-sectional study. Settings: Four major motor parks located at Ife Central LGA. Materials and Methods: Of the estimated 270 commercial drivers in the four major parks of the LGA, 215 consecutive drivers were interviewed and had their eyes examined. Structured questionnaires were administered by an ophthalmologist. Results: The prevalence of visual impairment (visual acuity < 6/18) in the better eye without correction was 3.3% ± 2.4 and there was a significant association between uncorrected visual acuity impairment in the better eye and RTA (P = 0.0152). Refractive error was seen in 8.4% of the drivers, but none of these wear corrective glasses. Visual field defect, abnormal stereopsis and color vision impairment did not have any significant association with RTA. Conclusion: Poor visual acuity is strongly associated with RTA amongst Nigerian commercial drivers as opposed to visual field defect, abnormal color vision and stereopsis. A significant proportion of visual impairment was due to uncorrected refractive errors. PMID:21938219

  3. FMRI of visual working memory in high school football players.

    PubMed

    Shenk, Trey E; Robinson, Meghan E; Svaldi, Diana O; Abbas, Kausar; Breedlove, Katherine M; Leverenz, Larry J; Nauman, Eric A; Talavage, Thomas M

    2015-01-01

    Visual working memory deficits have been observed in at-risk athletes. This study uses a visual N-back working memory functional magnetic resonance imaging task to longitudinally assess asymptomatic football athletes for abnormal activity. Athletes were increasingly "flagged" as the season progressed. Flagging may provide early detection of injury.

  4. How do musical tonality and experience affect visual working memory?

    PubMed

    Yang, Hua; Lu, Jing; Gong, Diankun; Yao, Dezhong

    2016-01-20

    The influence of music on the human brain has continued to attract increasing attention from neuroscientists and musicologists. Currently, tonal music is widely present in people's daily lives; however, atonal music has gradually become an important part of modern music. In this study, we conducted two experiments: the first one tested for differences in perception of distractibility between tonal music and atonal music. The second experiment tested how tonal music and atonal music affect visual working memory by comparing musicians and nonmusicians who were placed in contexts with background tonal music, atonal music, and silence. They were instructed to complete a delay matching memory task. The results show that musicians and nonmusicians have different evaluations of the distractibility of tonal music and atonal music, possibly indicating that long-term training may lead to a higher auditory perception threshold among musicians. For the working memory task, musicians reacted faster than nonmusicians in all background music cases, and musicians took more time to respond in the tonal background music condition than in the other conditions. Therefore, our results suggest that for a visual memory task, background tonal music may occupy more cognitive resources than atonal music or silence for musicians, leaving few resources left for the memory task. Moreover, the musicians outperformed the nonmusicians because of the higher sensitivity to background music, which also needs a further longitudinal study to be confirmed.

  5. Abnormal parietal encephalomalacia associated with schizophrenia: A case report.

    PubMed

    Pan, Fen; Wang, Jun-Yuan; Xu, Yi; Huang, Man-Li

    2017-03-01

    It is widely believed that structural abnormalities of the brain contribute to the pathophysiology of schizophrenia. The parietal lobe is a central hub of multisensory integration, and abnormities in this region might account for the clinical features of schizophrenia. However, few cases of parietal encephalomalacia associated with schizophrenia have been described. In this paper, we present a case of a 25-year-old schizophrenia patient with abnormal parietal encephalomalacia. The patient had poor nutrition and frequently had upper respiratory infections during childhood and adolescence. She showed severe schizophrenic symptoms such as visual hallucinations for 2 years. After examining all her possible medical conditions, we found that the patient had a lesion consistent with the diagnosis of encephalomalacia in her right parietal lobe and slight brain atrophy. The patient was prescribed olanzapine (10 mg per day). Her symptoms significantly improved after antipsychotic treatment and were still well controlled 1 year later. This case suggested that parietal encephalomalacia, which might be caused by inflammatory and infectious conditions in early life and be aggravated by undernutrition, might be implicated in the etiology of schizophrenia.

  6. Electrophysiological evidence of altered visual processing in adults who experienced visual deprivation during infancy.

    PubMed

    Segalowitz, Sidney J; Sternin, Avital; Lewis, Terri L; Dywan, Jane; Maurer, Daphne

    2017-04-01

    We examined the role of early visual input in visual system development by testing adults who had been born with dense bilateral cataracts that blocked all patterned visual input during infancy until the cataractous lenses were removed surgically and the eyes fitted with compensatory contact lenses. Patients viewed checkerboards and textures to explore early processing regions (V1, V2), Glass patterns to examine global form processing (V4), and moving stimuli to explore global motion processing (V5). Patients' ERPs differed from those of controls in that (1) the V1 component was much smaller for all but the simplest stimuli and (2) extrastriate components did not differentiate amongst texture stimuli, Glass patterns, or motion stimuli. The results indicate that early visual deprivation contributes to permanent abnormalities at early and mid levels of visual processing, consistent with enduring behavioral deficits in the ability to process complex textures, global form, and global motion. © 2017 Wiley Periodicals, Inc.

  7. Visual Semiotics & Uncertainty Visualization: An Empirical Study.

    PubMed

    MacEachren, A M; Roth, R E; O'Brien, J; Li, B; Swingley, D; Gahegan, M

    2012-12-01

    This paper presents two linked empirical studies focused on uncertainty visualization. The experiments are framed from two conceptual perspectives. First, a typology of uncertainty is used to delineate kinds of uncertainty matched with space, time, and attribute components of data. Second, concepts from visual semiotics are applied to characterize the kind of visual signification that is appropriate for representing those different categories of uncertainty. This framework guided the two experiments reported here. The first addresses representation intuitiveness, considering both visual variables and iconicity of representation. The second addresses relative performance of the most intuitive abstract and iconic representations of uncertainty on a map reading task. Combined results suggest initial guidelines for representing uncertainty and discussion focuses on practical applicability of results.

  8. [Acute visual loss in pregnancy caused by craniopharyngioma].

    PubMed

    Grillo-Mallo, E; Jiménez-Benito, J; Diéz-Feijóo, E; Alonso Alonso, I; Ferrero Collado, A; Muñoz Quiñones, S

    2014-04-01

    A 38-year-old female, at 20-weeks gestation, experienced a sudden visual loss and visual-field abnormalities. The neuroimaging tests showed a craniopharyngioma. Surgical removal was performed with a successful outcome as regards the pregnancy and visual function. It is known that pituitary adenomas may grow during pregnancy; however this is unusual in craniopharyngiomas. They usually present with visual problems due to their suprasellar topography. Surgery is the treatment of choice, the outcome essentially depending on its complete resection. Copyright © 2010 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  9. Intact anger recognition in depression despite aberrant visual facial information usage.

    PubMed

    Clark, Cameron M; Chiu, Carina G; Diaz, Ruth L; Goghari, Vina M

    2014-08-01

    Previous literature has indicated abnormalities in facial emotion recognition abilities, as well as deficits in basic visual processes in major depression. However, the literature is unclear on a number of important factors including whether or not these abnormalities represent deficient or enhanced emotion recognition abilities compared to control populations, and the degree to which basic visual deficits might impact this process. The present study investigated emotion recognition abilities for angry versus neutral facial expressions in a sample of undergraduate students with Beck Depression Inventory-II (BDI-II) scores indicative of moderate depression (i.e., ≥20), compared to matched low-BDI-II score (i.e., ≤2) controls via the Bubbles Facial Emotion Perception Task. Results indicated unimpaired behavioural performance in discriminating angry from neutral expressions in the high depressive symptoms group relative to the minimal depressive symptoms group, despite evidence of an abnormal pattern of visual facial information usage. The generalizability of the current findings is limited by the highly structured nature of the facial emotion recognition task used, as well as the use of an analog sample undergraduates scoring high in self-rated symptoms of depression rather than a clinical sample. Our findings suggest that basic visual processes are involved in emotion recognition abnormalities in depression, demonstrating consistency with the emotion recognition literature in other psychopathologies (e.g., schizophrenia, autism, social anxiety). Future research should seek to replicate these findings in clinical populations with major depression, and assess the association between aberrant face gaze behaviours and symptom severity and social functioning. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Showing the Unsayable: Participatory Visual Approaches and the Constitution of 'Patient Experience' in Healthcare Quality Improvement.

    PubMed

    Papoulias, Constantina

    2018-06-01

    This article considers the strengths and potential contributions of participatory visual methods for healthcare quality improvement research. It argues that such approaches may enable us to expand our understanding of 'patient experience' and of its potential for generating new knowledge for health systems. In particular, they may open up dimensions of people's engagement with services and treatments which exceed both the declarative nature of responses to questionnaires and the narrative sequencing of self reports gathered through qualitative interviewing. I will suggest that working with such methods may necessitate a more reflexive approach to the constitution of evidence in quality improvement work. To this end, the article will first consider the emerging rationale for the use of visual participatory methods in improvement before outlining the implications of two related approaches-photo-elicitation and PhotoVoice-for the constitution of 'experience'. It will then move to a participatory model for healthcare improvement work, Experience Based Co-Design (EBCD). It will argue that EBCD exemplifies both the strengths and the limitations of adequating visual participatory approaches to quality improvement ends. The article will conclude with a critical reflection on a small photographic study, in which the author participated, and which sought to harness service user perspectives for the design of psychiatric facilities, as a way of considering the potential contribution of visual participatory methods for quality improvement.

  11. Experiments on Auditory-Visual Perception of Sentences by Users of Unilateral, Bimodal, and Bilateral Cochlear Implants

    ERIC Educational Resources Information Center

    Dorman, Michael F.; Liss, Julie; Wang, Shuai; Berisha, Visar; Ludwig, Cimarron; Natale, Sarah Cook

    2016-01-01

    Purpose: Five experiments probed auditory-visual (AV) understanding of sentences by users of cochlear implants (CIs). Method: Sentence material was presented in auditory (A), visual (V), and AV test conditions to listeners with normal hearing and CI users. Results: (a) Most CI users report that most of the time, they have access to both A and V…

  12. A robust real-time abnormal region detection framework from capsule endoscopy images

    NASA Astrophysics Data System (ADS)

    Cheng, Yanfen; Liu, Xu; Li, Huiping

    2009-02-01

    In this paper we present a novel method to detect abnormal regions from capsule endoscopy images. Wireless Capsule Endoscopy (WCE) is a recent technology where a capsule with an embedded camera is swallowed by the patient to visualize the gastrointestinal tract. One challenge is one procedure of diagnosis will send out over 50,000 images, making physicians' reviewing process expensive. Physicians' reviewing process involves in identifying images containing abnormal regions (tumor, bleeding, etc) from this large number of image sequence. In this paper we construct a novel framework for robust and real-time abnormal region detection from large amount of capsule endoscopy images. The detected potential abnormal regions can be labeled out automatically to let physicians review further, therefore, reduce the overall reviewing process. In this paper we construct an abnormal region detection framework with the following advantages: 1) Trainable. Users can define and label any type of abnormal region they want to find; The abnormal regions, such as tumor, bleeding, etc., can be pre-defined and labeled using the graphical user interface tool we provided. 2) Efficient. Due to the large number of image data, the detection speed is very important. Our system can detect very efficiently at different scales due to the integral image features we used; 3) Robust. After feature selection we use a cascade of classifiers to further enforce the detection accuracy.

  13. Repetition blindness and illusory conjunctions: errors in binding visual types with visual tokens.

    PubMed

    Kanwisher, N

    1991-05-01

    Repetition blindness (Kanwisher, 1986, 1987) has been defined as the failure to detect or recall repetitions of words presented in rapid serial visual presentation (RSVP). The experiments presented here suggest that repetition blindness (RB) is a more general visual phenomenon, and examine its relationship to feature integration theory (Treisman & Gelade, 1980). Experiment 1 shows RB for letters distributed through space, time, or both. Experiment 2 demonstrates RB for repeated colors in RSVP lists. In Experiments 3 and 4, RB was found for repeated letters and colors in spatial arrays. Experiment 5 provides evidence that the mental representations of discrete objects (called "visual tokens" here) that are necessary to detect visual repetitions (Kanwisher, 1987) are the same as the "object files" (Kahneman & Treisman, 1984) in which visual features are conjoined. In Experiment 6, repetition blindness for the second occurrence of a repeated letter resulted only when the first occurrence was attended to. The overall results suggest that a general dissociation between types and tokens in visual information processing can account for both repetition blindness and illusory conjunctions.

  14. Abnormal ovarian cancer screening test result: women's informational, psychological and practical needs.

    PubMed

    Ryan, Patricia Y; Graves, Kristi D; Pavlik, Edward J; Andrykowski, Michael A

    2007-01-01

    Considerable effort has been devoted to the identification of cost-effective approaches to screening for ovarian cancer (OC). Transvaginal ultrasound (TVS) is one such screening approach. Approximately 5-7% of routine TVS screening tests yield abnormal results. Some women experience significant distress after receipt of an abnormal TVS screening test. Four focus groups provided in-depth, qualitative data regarding the informational, psychological, and practical needs of women after the receipt of an abnormal TVS result. Through question and content analytic procedures, we identified four themes: anticipation, emotional response, role of the screening technician, and impact of prior cancer experiences. Results provide initial guidance toward development of interventions to promote adaptive responses after receipt of an abnormal cancer screening test result.

  15. An Empirical Study on Using Visual Embellishments in Visualization.

    PubMed

    Borgo, R; Abdul-Rahman, A; Mohamed, F; Grant, P W; Reppa, I; Floridi, L; Chen, Min

    2012-12-01

    In written and spoken communications, figures of speech (e.g., metaphors and synecdoche) are often used as an aid to help convey abstract or less tangible concepts. However, the benefits of using rhetorical illustrations or embellishments in visualization have so far been inconclusive. In this work, we report an empirical study to evaluate hypotheses that visual embellishments may aid memorization, visual search and concept comprehension. One major departure from related experiments in the literature is that we make use of a dual-task methodology in our experiment. This design offers an abstraction of typical situations where viewers do not have their full attention focused on visualization (e.g., in meetings and lectures). The secondary task introduces "divided attention", and makes the effects of visual embellishments more observable. In addition, it also serves as additional masking in memory-based trials. The results of this study show that visual embellishments can help participants better remember the information depicted in visualization. On the other hand, visual embellishments can have a negative impact on the speed of visual search. The results show a complex pattern as to the benefits of visual embellishments in helping participants grasp key concepts from visualization.

  16. Combining universal beauty and cultural context in a unifying model of visual aesthetic experience.

    PubMed

    Redies, Christoph

    2015-01-01

    In this work, I propose a model of visual aesthetic experience that combines formalist and contextual aspects of aesthetics. The model distinguishes between two modes of processing. First, perceptual processing is based on the intrinsic form of an artwork, which may or may not be beautiful. If it is beautiful, a beauty-responsive mechanism is activated in the brain. This bottom-up mechanism is universal amongst humans; it is widespread in the visual brain and responsive across visual modalities. Second, cognitive processing is based on contextual information, such as the depicted content, the intentions of the artist or the circumstances of the presentation of the artwork. Cognitive processing is partially top-down and varies between individuals according to their cultural experience. Processing in the two channels is parallel and largely independent. In the general case, an aesthetic experience is induced if processing in both channels is favorable, i.e., if there is resonance in the perceptual processing channel ("aesthetics of perception"), and successful mastering in the cognitive processing channel ("aesthetics of cognition"). I speculate that this combinatorial mechanism has evolved to mediate social bonding between members of a (cultural) group of people. Primary emotions can be elicited via both channels and modulate the degree of the aesthetic experience. Two special cases are discussed. First, in a subset of (post-)modern art, beauty no longer plays a prominent role. Second, in some forms of abstract art, beautiful form can be enjoyed with minimal cognitive processing. The model is applied to examples of Western art. Finally, implications of the model are discussed. In summary, the proposed model resolves the seeming contradiction between formalist perceptual approaches to aesthetic experience, which are based on the intrinsic beauty of artworks, and contextual approaches, which account for highly individual and culturally dependent aspects of aesthetics.

  17. Combining universal beauty and cultural context in a unifying model of visual aesthetic experience

    PubMed Central

    Redies, Christoph

    2015-01-01

    In this work, I propose a model of visual aesthetic experience that combines formalist and contextual aspects of aesthetics. The model distinguishes between two modes of processing. First, perceptual processing is based on the intrinsic form of an artwork, which may or may not be beautiful. If it is beautiful, a beauty-responsive mechanism is activated in the brain. This bottom–up mechanism is universal amongst humans; it is widespread in the visual brain and responsive across visual modalities. Second, cognitive processing is based on contextual information, such as the depicted content, the intentions of the artist or the circumstances of the presentation of the artwork. Cognitive processing is partially top–down and varies between individuals according to their cultural experience. Processing in the two channels is parallel and largely independent. In the general case, an aesthetic experience is induced if processing in both channels is favorable, i.e., if there is resonance in the perceptual processing channel (“aesthetics of perception”), and successful mastering in the cognitive processing channel (“aesthetics of cognition”). I speculate that this combinatorial mechanism has evolved to mediate social bonding between members of a (cultural) group of people. Primary emotions can be elicited via both channels and modulate the degree of the aesthetic experience. Two special cases are discussed. First, in a subset of (post-)modern art, beauty no longer plays a prominent role. Second, in some forms of abstract art, beautiful form can be enjoyed with minimal cognitive processing. The model is applied to examples of Western art. Finally, implications of the model are discussed. In summary, the proposed model resolves the seeming contradiction between formalist perceptual approaches to aesthetic experience, which are based on the intrinsic beauty of artworks, and contextual approaches, which account for highly individual and culturally dependent aspects of

  18. Sensori-motor experience leads to changes in visual processing in the developing brain.

    PubMed

    James, Karin Harman

    2010-03-01

    Since Broca's studies on language processing, cortical functional specialization has been considered to be integral to efficient neural processing. A fundamental question in cognitive neuroscience concerns the type of learning that is required for functional specialization to develop. To address this issue with respect to the development of neural specialization for letters, we used functional magnetic resonance imaging (fMRI) to compare brain activation patterns in pre-school children before and after different letter-learning conditions: a sensori-motor group practised printing letters during the learning phase, while the control group practised visual recognition. Results demonstrated an overall left-hemisphere bias for processing letters in these pre-literate participants, but, more interestingly, showed enhanced blood oxygen-level-dependent activation in the visual association cortex during letter perception only after sensori-motor (printing) learning. It is concluded that sensori-motor experience augments processing in the visual system of pre-school children. The change of activation in these neural circuits provides important evidence that 'learning-by-doing' can lay the foundation for, and potentially strengthen, the neural systems used for visual letter recognition.

  19. Abnormal Grief: Should We Consider a More Patient-Centered Approach?

    PubMed

    Moayedoddin, Babak; Markowitz, John C

    2015-01-01

    Grief, the psychological reaction to the loss of a significant other, varies complexly in its cause, experience, evolution, and prognosis. Although most bereaved individuals experience a normal grieving process, some develop complicated grief (CG) or major depressive disorder (MDD). The DSM-5, which controversially altered the nosology, recognizes grief-related major depression (GRMD) as a diagnostic subtype if a patient meets MDD criteria two weeks post bereavement. The (DSM-5) tries to distinguish between grief and MDD, but remains a symptom-based, centered approach to grief that is not patient centered. This article reviews grief in its normal and abnormal dimensions. Using an illustrative clinical case in which interpersonal psychotherapy (IPT) was employed, we discuss the need for a more patient-centered approach to treating abnormal grief, considering the patient's personal history, perceptions, experiences of bereavement, and interpersonal environment. Clinical studies need to better identify subgroups of individuals susceptible to abnormal grief and to evaluate their response to early interventions.

  20. Anomalous visual experiences, negative symptoms, perceptual organization and the magnocellular pathway in schizophrenia: a shared construct?

    PubMed

    Kéri, Szabolcs; Kiss, Imre; Kelemen, Oguz; Benedek, György; Janka, Zoltán

    2005-10-01

    Schizophrenia is associated with impaired visual information processing. The aim of this study was to investigate the relationship between anomalous perceptual experiences, positive and negative symptoms, perceptual organization, rapid categorization of natural images and magnocellular (M) and parvocellular (P) visual pathway functioning. Thirty-five unmedicated patients with schizophrenia and 20 matched healthy control volunteers participated. Anomalous perceptual experiences were assessed with the Bonn Scale for the Assessment Basic Symptoms (BSABS). General intellectual functions were evaluated with the revised version of the Wechsler Adult Intelligence Scale. The 1-9 version of the Continuous Performance Test (CPT) was used to investigate sustained attention. The following psychophysical tests were used: detection of Gabor patches with collinear and orthogonal flankers (perceptual organization), categorization of briefly presented natural scenes (rapid visual processing), low-contrast and frequency-doubling vernier threshold (M pathway functioning), isoluminant colour vernier threshold and high spatial frequency discrimination (P pathway functioning). The patients with schizophrenia were impaired on test of perceptual organization, rapid visual processing and M pathway functioning. There was a significant correlation between BSABS scores, negative symptoms, perceptual organization, rapid visual processing and M pathway functioning. Positive symptoms, IQ, CPT and P pathway measures did not correlate with these parameters. The best predictor of the BSABS score was the perceptual organization deficit. These results raise the possibility that multiple facets of visual information processing deficits can be explained by M pathway dysfunctions in schizophrenia, resulting in impaired attentional modulation of perceptual organization and of natural image categorization.

  1. Words, Shape, Visual Search and Visual Working Memory in 3-Year-Old Children

    ERIC Educational Resources Information Center

    Vales, Catarina; Smith, Linda B.

    2015-01-01

    Do words cue children's visual attention, and if so, what are the relevant mechanisms? Across four experiments, 3-year-old children (N = 163) were tested in visual search tasks in which targets were cued with only a visual preview versus a visual preview and a spoken name. The experiments were designed to determine whether labels facilitated…

  2. Visual Half-Field Experiments Are a Good Measure of Cerebral Language Dominance if Used Properly: Evidence from fMRI

    ERIC Educational Resources Information Center

    Hunter, Zoe R.; Brysbaert, Marc

    2008-01-01

    Traditional neuropsychology employs visual half-field (VHF) experiments to assess cerebral language dominance. This approach is based on the assumption that left cerebral dominance for language leads to faster and more accurate recognition of words in the right visual half-field (RVF) than in the left visual half-field (LVF) during tachistoscopic…

  3. A Virtual Rock Physics Laboratory Through Visualized and Interactive Experiments

    NASA Astrophysics Data System (ADS)

    Vanorio, T.; Di Bonito, C.; Clark, A. C.

    2014-12-01

    As new scientific challenges demand more comprehensive and multidisciplinary investigations, laboratory experiments are not expected to become simpler and/or faster. Experimental investigation is an indispensable element of scientific inquiry and must play a central role in the way current and future generations of scientist make decisions. To turn the complexity of laboratory work (and that of rocks!) into dexterity, engagement, and expanded learning opportunities, we are building an interactive, virtual laboratory reproducing in form and function the Stanford Rock Physics Laboratory, at Stanford University. The objective is to combine lectures on laboratory techniques and an online repository of visualized experiments consisting of interactive, 3-D renderings of equipment used to measure properties central to the study of rock physics (e.g., how to saturate rocks, how to measure porosity, permeability, and elastic wave velocity). We use a game creation system together with 3-D computer graphics, and a narrative voice to guide the user through the different phases of the experimental protocol. The main advantage gained in employing computer graphics over video footage is that students can virtually open the instrument, single out its components, and assemble it. Most importantly, it helps describe the processes occurring within the rock. These latter cannot be tracked while simply recording the physical experiment, but computer animation can efficiently illustrate what happens inside rock samples (e.g., describing acoustic waves, and/or fluid flow through a porous rock under pressure within an opaque core-holder - Figure 1). The repository of visualized experiments will complement lectures on laboratory techniques and constitute an on-line course offered through the EdX platform at Stanford. This will provide a virtual laboratory for anyone, anywhere to facilitate teaching/learning of introductory laboratory classes in Geophysics and expand the number of courses

  4. Abnormal Uterine Bleeding: American College of Nurse-Midwives.

    PubMed

    2016-07-01

    Variations in uterine bleeding, termed abnormal uterine bleeding, occur commonly among women and often are physiologic in nature with no significant consequences. However, abnormal uterine bleeding can cause significant distress to women or may signify an underlying pathologic condition. Most women experience variations in menstrual and perimenstrual bleeding in their lifetimes; therefore, the ability of the midwife to differentiate between normal and abnormal bleeding is a key diagnostic skill. A comprehensive history and use of the PALM-COEIN classification system will provide clear guidelines for clinical management, evidence-based treatment, and an individualized plan of care. The purpose of this Clinical Bulletin is to define and describe classifications of abnormal uterine bleeding, review updated terminology, and identify methods of assessment and treatment using a woman-centered approach. © 2016 by the American College of Nurse-Midwives.

  5. How cortical neurons help us see: visual recognition in the human brain

    PubMed Central

    Blumberg, Julie; Kreiman, Gabriel

    2010-01-01

    Through a series of complex transformations, the pixel-like input to the retina is converted into rich visual perceptions that constitute an integral part of visual recognition. Multiple visual problems arise due to damage or developmental abnormalities in the cortex of the brain. Here, we provide an overview of how visual information is processed along the ventral visual cortex in the human brain. We discuss how neurophysiological recordings in macaque monkeys and in humans can help us understand the computations performed by visual cortex. PMID:20811161

  6. Comparison of multifocal visual evoked potential, static automated perimetry, and optical coherence tomography findings for assessing visual pathways in patients with pituitary adenomas.

    PubMed

    Qiao, Nidan; Zhang, Yichao; Ye, Zhao; Shen, Ming; Shou, Xuefei; Wang, Yongfei; Li, Shiqi; Wang, Min; Zhao, Yao

    2015-10-01

    There have been no studies investigating the correlation between structural [thickness of the retinal nerve fiber layer (RNFL) as determined by optical coherence tomography (OCT)] and functional [Humphrey visual field (HVF) or visual evoked potential (VEP) amplitude] measures of optic nerve integrity in patients with pituitary adenomas (PA). Patients with PAs were recruited between September 2010 and September 2013. OCT, standard automated perimetry (SAP), and multifical VEP (mfVEP) were performed. Agreement between OCT, SAP, and mfVEP values in classifying eyes/quadrants was determined using AC1 statistics. Pearson's correlation was used to examine relationships between structural and functional data. In total, 88.7% of the eyes tested showed abnormal SAP findings and 93.7% showed abnormal mfVEP findings. Only 14.8% of the eyes showed abnormal OCT findings. The agreement between SAP and mfVEP findings was 88.9% (AC1 = 0.87). The agreement between OCT and mfVEP findings was 24.2% (AC1 = -0.52), and that between OCT and SAP findings was 21.5% (AC1 = -0.56). The correlation values between RNFL thickness and the functional measurements were -0.601 for the mfVEP score (P = 0.000) and -0.441 for the SAP score (P = 0.000). The correlation between the mfVEP and SAP scores was -0.617 (P = 0.000). mfVEP, SAP, and OCT provided complementary information for detecting visual pathway abnormalities in patients with PAs. Good agreement was demonstrated between SAP and mfVEP and quantitative analysis of structure-function measurements revealed a moderate correlation.

  7. Feedforward and feedback motor control abnormalities implicate cerebellar dysfunctions in autism spectrum disorder.

    PubMed

    Mosconi, Matthew W; Mohanty, Suman; Greene, Rachel K; Cook, Edwin H; Vaillancourt, David E; Sweeney, John A

    2015-02-04

    Sensorimotor abnormalities are common in autism spectrum disorder (ASD) and among the earliest manifestations of the disorder. They have been studied far less than the social-communication and cognitive deficits that define ASD, but a mechanistic understanding of sensorimotor abnormalities in ASD may provide key insights into the neural underpinnings of the disorder. In this human study, we examined rapid, precision grip force contractions to determine whether feedforward mechanisms supporting initial motor output before sensory feedback can be processed are disrupted in ASD. Sustained force contractions also were examined to determine whether reactive adjustments to ongoing motor behavior based on visual feedback are altered. Sustained force was studied across multiple force levels and visual gains to assess motor and visuomotor mechanisms, respectively. Primary force contractions of individuals with ASD showed greater peak rate of force increases and large transient overshoots. Individuals with ASD also showed increased sustained force variability that scaled with force level and was more severe when visual gain was highly amplified or highly degraded. When sustaining a constant force level, their reactive adjustments were more periodic than controls, and they showed increased reliance on slower feedback mechanisms. Feedforward and feedback mechanism alterations each were associated with more severe social-communication impairments in ASD. These findings implicate anterior cerebellar circuits involved in feedforward motor control and posterior cerebellar circuits involved in transforming visual feedback into precise motor adjustments in ASD. Copyright © 2015 the authors 0270-6474/15/352015-11$15.00/0.

  8. Feedforward and Feedback Motor Control Abnormalities Implicate Cerebellar Dysfunctions in Autism Spectrum Disorder

    PubMed Central

    Mohanty, Suman; Greene, Rachel K.; Cook, Edwin H.; Vaillancourt, David E.; Sweeney, John A.

    2015-01-01

    Sensorimotor abnormalities are common in autism spectrum disorder (ASD) and among the earliest manifestations of the disorder. They have been studied far less than the social-communication and cognitive deficits that define ASD, but a mechanistic understanding of sensorimotor abnormalities in ASD may provide key insights into the neural underpinnings of the disorder. In this human study, we examined rapid, precision grip force contractions to determine whether feedforward mechanisms supporting initial motor output before sensory feedback can be processed are disrupted in ASD. Sustained force contractions also were examined to determine whether reactive adjustments to ongoing motor behavior based on visual feedback are altered. Sustained force was studied across multiple force levels and visual gains to assess motor and visuomotor mechanisms, respectively. Primary force contractions of individuals with ASD showed greater peak rate of force increases and large transient overshoots. Individuals with ASD also showed increased sustained force variability that scaled with force level and was more severe when visual gain was highly amplified or highly degraded. When sustaining a constant force level, their reactive adjustments were more periodic than controls, and they showed increased reliance on slower feedback mechanisms. Feedforward and feedback mechanism alterations each were associated with more severe social-communication impairments in ASD. These findings implicate anterior cerebellar circuits involved in feedforward motor control and posterior cerebellar circuits involved in transforming visual feedback into precise motor adjustments in ASD. PMID:25653359

  9. Abnormal Size-Dependent Modulation of Motion Perception in Children with Autism Spectrum Disorder (ASD).

    PubMed

    Sysoeva, Olga V; Galuta, Ilia A; Davletshina, Maria S; Orekhova, Elena V; Stroganova, Tatiana A

    2017-01-01

    Excitation/Inhibition (E/I) imbalance in neural networks is now considered among the core neural underpinnings of autism psychopathology. In motion perception at least two phenomena critically depend on E/I balance in visual cortex: spatial suppression (SS), and spatial facilitation (SF) corresponding to impoverished or improved motion perception with increasing stimuli size, respectively. While SS is dominant at high contrast, SF is evident for low contrast stimuli, due to the prevalence of inhibitory contextual modulations in the former, and excitatory ones in the latter case. Only one previous study (Foss-Feig et al., 2013) investigated SS and SF in Autism Spectrum Disorder (ASD). Our study aimed to replicate previous findings, and to explore the putative contribution of deficient inhibitory influences into an enhanced SF index in ASD-a cornerstone for interpretation proposed by Foss-Feig et al. (2013). The SS and SF were examined in 40 boys with ASD, broad spectrum of intellectual abilities (63 < IQ < 127) and 44 typically developing (TD) boys, aged 6-15 years. The stimuli of small (1°) and large (12°) radius were presented under high (100%) and low (1%) contrast conditions. Social Responsiveness Scale and Sensory Profile Questionnaire were used to assess the autism severity and sensory processing abnormalities. We found that the SS index was atypically reduced, while SF index abnormally enhanced in children with ASD. The presence of abnormally enhanced SF in children with ASD was the only consistent finding between our study and that of Foss-Feig et al. While the SS and SF indexes were strongly interrelated in TD participants, this correlation was absent in their peers with ASD. In addition, the SF index but not the SS index correlated with the severity of autism and the poor registration abilities. The pattern of results is partially consistent with the idea of hypofunctional inhibitory transmission in visual areas in ASD. Nonetheless, the absence of

  10. Abnormal Size-Dependent Modulation of Motion Perception in Children with Autism Spectrum Disorder (ASD)

    PubMed Central

    Sysoeva, Olga V.; Galuta, Ilia A.; Davletshina, Maria S.; Orekhova, Elena V.; Stroganova, Tatiana A.

    2017-01-01

    Excitation/Inhibition (E/I) imbalance in neural networks is now considered among the core neural underpinnings of autism psychopathology. In motion perception at least two phenomena critically depend on E/I balance in visual cortex: spatial suppression (SS), and spatial facilitation (SF) corresponding to impoverished or improved motion perception with increasing stimuli size, respectively. While SS is dominant at high contrast, SF is evident for low contrast stimuli, due to the prevalence of inhibitory contextual modulations in the former, and excitatory ones in the latter case. Only one previous study (Foss-Feig et al., 2013) investigated SS and SF in Autism Spectrum Disorder (ASD). Our study aimed to replicate previous findings, and to explore the putative contribution of deficient inhibitory influences into an enhanced SF index in ASD—a cornerstone for interpretation proposed by Foss-Feig et al. (2013). The SS and SF were examined in 40 boys with ASD, broad spectrum of intellectual abilities (63 < IQ < 127) and 44 typically developing (TD) boys, aged 6–15 years. The stimuli of small (1°) and large (12°) radius were presented under high (100%) and low (1%) contrast conditions. Social Responsiveness Scale and Sensory Profile Questionnaire were used to assess the autism severity and sensory processing abnormalities. We found that the SS index was atypically reduced, while SF index abnormally enhanced in children with ASD. The presence of abnormally enhanced SF in children with ASD was the only consistent finding between our study and that of Foss-Feig et al. While the SS and SF indexes were strongly interrelated in TD participants, this correlation was absent in their peers with ASD. In addition, the SF index but not the SS index correlated with the severity of autism and the poor registration abilities. The pattern of results is partially consistent with the idea of hypofunctional inhibitory transmission in visual areas in ASD. Nonetheless, the absence of

  11. Relationship Between Rates of Binocular Visual Field Loss and Vision-Related Quality of Life in Glaucoma

    PubMed Central

    Lisboa, Renato; Chun, Yeoun Sook; Zangwill, Linda M.; Weinreb, Robert N.; Rosen, Peter N.; Liebmann, Jeffrey M.; Girkin, Christopher A.; Medeiros, Felipe A.

    2013-01-01

    Objective To evaluate the relationship between binocular rates of visual field change and vision-related quality of life (VRQOL) in glaucoma. Methods The study included 796 eyes of 398 participants that had diagnosed or suspected glaucoma followed for an average of 7.3 ± 2.0 years. Subjects were recruited from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES). VRQOL was evaluated using the National Eye Institute Visual Function Questionnaire (NEI VFQ-25) at the last follow-up visit. Integrated binocular visual fields (BVF) were calculated from the monocular fields of each patient. Linear regression of mean deviation (MD) values was used to evaluate rates of visual field change during the follow-up period. Logistic regression models were used to investigate the relationship between abnormal VRQOL and rates of visual field change, while adjusting for potentially confounding socio-economic and demographic variables. Results Thirty-two patients (8.0%) had abnormal VRQOL as determined by the results of the NEI VFQ-25 questionnaire. Subjects with abnormal VRQOL had significantly faster rates of BVF change than those with normal VRQOL (−0.18 db/year vs. −0.06 dB/year, respectively; P < 0.001). Rates of BVF change were significantly associated with abnormality in VRQOL (OR = 1.31 per 0.1dB/year faster; P = 0.038), after adjustment for confounding variables. Conclusions Patients with faster rates of BVF change were at higher risk of reporting abnormal VRQOL. Assessment of rates of BVF change may provide useful information in determining risk of functional impairment in glaucoma. PMID:23450425

  12. VISUAL ACUITY IN PSEUDOXANTHOMA ELASTICUM.

    PubMed

    Risseeuw, Sara; Ossewaarde-van Norel, Jeannette; Klaver, Caroline C W; Colijn, Johanna M; Imhof, Saskia M; van Leeuwen, Redmer

    2018-04-12

    To assess the age-specific proportion of visual impairment in patients with pseudoxanthoma elasticum (PXE) and to compare this with foveal abnormality and similar data of late age-related macular degeneration patients. Cross-sectional data of 195 patients with PXE were reviewed, including best-corrected visual acuity and imaging. The World Health Organisation criteria were used to categorize bilateral visual impairment. These results were compared with similar data of 131 patients with late age-related macular degeneration from the Rotterdam study. Overall, 50 PXE patients (26.0%) were visually impaired, including 21 (11%) with legal blindness. Visual functioning declined with increasing age. In patients older than 50 years, 37% was visually impaired and 15% legally blind. Foveal choroidal neovascularization was found in 84% of eyes with a best-corrected visual acuity lower than 20/70 (0.30) and macular atrophy in the fovea in 16%. In late age-related macular degeneration patients, 40% were visually impaired and 13% legally blind. Visual impairment started approximately 20 years later as compared with PXE patients. Visual impairment and blindness are frequent in PXE, particularly in patients older than 50 years. Although choroidal neovascularization is associated with the majority of vision loss, macular atrophy is also common. The proportion of visual impairment in PXE is comparable with late age-related macular degeneration but manifests earlier in life.

  13. Adult Visual Experience Promotes Recovery of Primary Visual Cortex from Long-Term Monocular Deprivation

    ERIC Educational Resources Information Center

    Fischer, Quentin S.; Aleem, Salman; Zhou, Hongyi; Pham, Tony A.

    2007-01-01

    Prolonged visual deprivation from early childhood to maturity is believed to cause permanent visual impairment. However, there have been case reports of substantial improvement of binocular vision in human adults following lifelong visual impairment or deprivation. These observations, together with recent findings of adult ocular dominance…

  14. Retinal detachment in hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome: Color vision abnormality as the first and predominant manifestation.

    PubMed

    Morisawa, Hiroyuki; Makino, Shinji; Takahashi, Hironori; Sorita, Mari; Matsubara, Shigeki

    2015-11-01

    Serous retinal detachment is sometimes caused by hypertensive disorders in pregnancy and its associated conditions, in which the predominant eye symptoms are blurred vision, distorted vision, and reduced visual acuity. To our best knowledge, this is the first report of a puerperal woman with hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome in whom color vision abnormality was the first and predominant manifestation of serous retinal detachment. At 32 weeks of gestation, the 34-year-old Japanese woman underwent cesarean section due to HELLP syndrome. She complained of color vision abnormality on day 1 post-partum and ophthalmological examination revealed serous retinal detachment of both eyes. The visual acuity was preserved. With supportive therapy, her color vision abnormality gradually ameliorated and retinal detachment completely resolved on day 34 post-partum without any sequelae. Obstetricians should be aware that color vision abnormality can be the first and predominant symptom of HELLP-related serous retinal detachment. © 2015 Japan Society of Obstetrics and Gynecology.

  15. Entwining Psychology and Visual Arts: A Classroom Experience

    ERIC Educational Resources Information Center

    Bahia, Sara; Trindade, Jose Pedro

    2012-01-01

    The purpose of this paper is to show how activating perception, imagery and creativity facilitate the mastery of specific skills of visual arts education. Specifically, the study aimed at answering two questions: How can teachers enhance visual and creative expression?; and What criteria should be used to evaluate specific learning of visual arts…

  16. Experience-Dependent Hemispheric Specialization of Letters and Numbers is Revealed in Early Visual Processing

    PubMed Central

    Park, Joonkoo; Chiang, Crystal; Brannon, Elizabeth M.; Woldorff, Marty G.

    2014-01-01

    Recent functional magnetic resonance imaging research has demonstrated that letters and numbers are preferentially processed in distinct regions and hemispheres in the visual cortex. In particular, the left visual cortex preferentially processes letters compared to numbers, while the right visual cortex preferentially processes numbers compared to letters. Because letters and numbers are cultural inventions and are otherwise physically arbitrary, such a double dissociation is strong evidence for experiential effects on neural architecture. Here, we use the high temporal resolution of event-related potentials (ERPs) to investigate the temporal dynamics of the neural dissociation between letters and numbers. We show that the divergence between ERP traces to letters and numbers emerges very early in processing. Letters evoked greater N1 waves (latencies 140–170 ms) than did numbers over left occipital channels, while numbers evoked greater N1s than letters over the right, suggesting letters and numbers are preferentially processed in opposite hemispheres early in visual encoding. Moreover, strings of letters, but not single letters, elicited greater P2 ERP waves, (starting around 250 ms) than numbers did over the left hemisphere, suggesting that the visual cortex is tuned to selectively process combinations of letters, but not numbers, further along in the visual processing stream. Additionally, the processing of both of these culturally defined stimulus types differentiated from similar but unfamiliar visual stimulus forms (false fonts) even earlier in the processing stream (the P1 at 100 ms). These findings imply major cortical specialization processes within the visual system driven by experience with reading and mathematics. PMID:24669789

  17. Experience-dependent hemispheric specialization of letters and numbers is revealed in early visual processing.

    PubMed

    Park, Joonkoo; Chiang, Crystal; Brannon, Elizabeth M; Woldorff, Marty G

    2014-10-01

    Recent fMRI research has demonstrated that letters and numbers are preferentially processed in distinct regions and hemispheres in the visual cortex. In particular, the left visual cortex preferentially processes letters compared with numbers, whereas the right visual cortex preferentially processes numbers compared with letters. Because letters and numbers are cultural inventions and are otherwise physically arbitrary, such a double dissociation is strong evidence for experiential effects on neural architecture. Here, we use the high temporal resolution of ERPs to investigate the temporal dynamics of the neural dissociation between letters and numbers. We show that the divergence between ERP traces to letters and numbers emerges very early in processing. Letters evoked greater N1 waves (latencies 140-170 msec) than did numbers over left occipital channels, whereas numbers evoked greater N1s than letters over the right, suggesting letters and numbers are preferentially processed in opposite hemispheres early in visual encoding. Moreover, strings of letters, but not single letters, elicited greater P2 ERP waves (starting around 250 msec) than numbers did over the left hemisphere, suggesting that the visual cortex is tuned to selectively process combinations of letters, but not numbers, further along in the visual processing stream. Additionally, the processing of both of these culturally defined stimulus types differentiated from similar but unfamiliar visual stimulus forms (false fonts) even earlier in the processing stream (the P1 at 100 msec). These findings imply major cortical specialization processes within the visual system driven by experience with reading and mathematics.

  18. The Effect of Visual Experience on Perceived Haptic Verticality When Tilted in the Roll Plane

    PubMed Central

    Cuturi, Luigi F.; Gori, Monica

    2017-01-01

    The orientation of the body in space can influence perception of verticality leading sometimes to biases consistent with priors peaked at the most common head and body orientation, that is upright. In this study, we investigate haptic perception of verticality in sighted individuals and early and late blind adults when tilted counterclockwise in the roll plane. Participants were asked to perform a stimulus orientation discrimination task with their body tilted to their left ear side 90° relative to gravity. Stimuli were presented by using a motorized haptic bar. In order to test whether different reference frames relative to the head influenced perception of verticality, we varied the position of the stimulus on the body longitudinal axis. Depending on the stimulus position sighted participants tended to have biases away or toward their body tilt. Visually impaired individuals instead show a different pattern of verticality estimations. A bias toward head and body tilt (i.e., Aubert effect) was observed in late blind individuals. Interestingly, no strong biases were observed in early blind individuals. Overall, these results posit visual sensory information to be fundamental in influencing the haptic readout of proprioceptive and vestibular information about body orientation relative to gravity. The acquisition of an idiotropic vector signaling the upright might take place through vision during development. Regarding early blind individuals, independent spatial navigation experience likely enhanced by echolocation behavior might have a role in such acquisition. In the case of participants with late onset blindness, early experience of vision might lead them to anchor their visually acquired priors to the haptic modality with no disambiguation between head and body references as observed in sighted individuals (Fraser et al., 2015). With our study, we aim to investigate haptic perception of gravity direction in unusual body tilts when vision is absent due to visual

  19. Replacement of the Faces subtest by Visual Reproductions within Wechsler Memory Scale-Third Edition (WMS-III) visual memory indexes: implications for discrepancy analysis.

    PubMed

    Hawkins, Keith A; Tulsky, David S

    2004-06-01

    Within discrepancy analysis differences between scores are examined for abnormality. Although larger differences are generally associated with rising impairment probabilities, the relationship between discrepancy size and abnormality varies across score pairs in relation to the correlation between the contrasted scores in normal subjects. Examinee ability level also affects the size of discrepancies observed normally. Wechsler Memory Scale-Third Edition (WMS-III) visual index scores correlate only modestly with other Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) and WMS-III index scores; consequently, differences between these scores and others have to be very large before they become unusual, especially for subjects of higher intelligence. The substitution of the Faces subtest by Visual Reproductions within visual memory indexes formed by the combination of WMS-III visual subtests (creating immediate recall, delayed recall, and combined immediate and delayed index scores) results in higher correlation coefficients, and a decline in the discrepancy size required to surpass base rate thresholds for probable impairment. This gain appears not to occur at the cost of a diminished sensitivity to diverse pathologies. New WMS-III discrepancy base rate data are supplied to complement those currently available to clinicians.

  20. High lifetime probability of screen-detected cervical abnormalities.

    PubMed

    Pankakoski, Maiju; Heinävaara, Sirpa; Sarkeala, Tytti; Anttila, Ahti

    2017-12-01

    Objective Regular screening and follow-up is an important key to cervical cancer prevention; however, screening inevitably detects mild or borderline abnormalities that would never progress to a more severe stage. We analysed the cumulative probability and recurrence of cervical abnormalities in the Finnish organized screening programme during a 22-year follow-up. Methods Screening histories were collected for 364,487 women born between 1950 and 1965. Data consisted of 1 207,017 routine screens and 88,143 follow-up screens between 1991 and 2012. Probabilities of cervical abnormalities by age were estimated using logistic regression and generalized estimating equations methodology. Results The probability of experiencing any abnormality at least once at ages 30-64 was 34.0% (95% confidence interval [CI]: 33.3-34.6%) . Probability was 5.4% (95% CI: 5.0-5.8%) for results warranting referral and 2.2% (95% CI: 2.0-2.4%) for results with histologically confirmed findings. Previous occurrences were associated with an increased risk of detecting new ones, specifically in older women. Conclusion A considerable proportion of women experience at least one abnormal screening result during their lifetime, and yet very few eventually develop an actual precancerous lesion. Re-evaluation of diagnostic criteria concerning mild abnormalities might improve the balance of harms and benefits of screening. Special monitoring of women with recurrent abnormalities especially at older ages may also be needed.

  1. A Qualitatively Different Experience: Mainstreaming Pupils with a Visual Impairment in Northern Ireland

    ERIC Educational Resources Information Center

    Gray, Colette

    2009-01-01

    This paper reports the experiences of special education needs co-ordinators (SENCOs) on the inclusion of pupils with a visual impairment (VI) in mainstream schools in Northern Ireland. A mixed method approach (postal questionnaire survey (n=113) and interviews (n=6)) was utilised to triangulate the findings. The results indicate an inverse…

  2. Visual Behaviors and Adaptations Associated with Cortical and Ocular Impairment in Children.

    ERIC Educational Resources Information Center

    Jan, J. E.; Groenveld, M.

    1993-01-01

    This article shows the usefulness of understanding visual behaviors in the diagnosis of various types of visual impairments that are due to ocular and cortical disorders. Behaviors discussed include nystagmus, ocular motor dyspraxia, head position, close viewing, field loss adaptations, mannerisms, photophobia, and abnormal color perception. (JDD)

  3. The Impact of a Visual Imagery Intervention on Army ROTC Cadets' Marksmanship Performance and Flow Experiences

    ERIC Educational Resources Information Center

    Rakes, Edward Lee

    2012-01-01

    This investigation used an experimental design to examine how a visual imagery intervention and two levels of challenge would affect the flow experiences and performance of cadets engaged in Army ROTC marksmanship training. I employed MANCOVA analyses, with gender and prior marksmanship training experience as covariates, to assess cadets' (n =…

  4. Nightmare and Abnormal Dreams: Rare Side Effects of Metformin?

    PubMed Central

    Yanto, Theo Audi; Kosasih, Felicia Nathania

    2018-01-01

    Background Metformin is widely known as an antidiabetic agent which has significant gastrointestinal side effects, but nightmares and abnormal dreams as its adverse reactions are not well reported. Case Presentation Herein we present a case of 56-year-old male patient with no known history of recurrent nightmares and sleep disorder, experiencing nightmare and abnormal dreams directly after consumption of 750 mg extended release metformin. He reported his dream as an unpleasant experience which awakened him at night with negative feelings. The nightmare only lasted for a night, but his dreams every night thereafter seemed abnormal. The dreams were vivid and indescribable. The disappearance and occurrence of abnormal dreams ensued soon after the drug was discontinued and rechallenged. The case was assessed using Naranjo Adverse Drug Reaction (ADR) probability scale and resulted as probable causality. Conclusion Metformin might be the underlying cause of nightmare and abnormal dreams in this patient. More studies are needed to confirm the association and causality of this findings. PMID:29581904

  5. Inter-Rater Reliability for Speech-Language Therapists' Judgement of Oesophageal Abnormality during Oesophageal Visualization

    ERIC Educational Resources Information Center

    Miles, Anna

    2017-01-01

    Background: Oesophageal abnormalities are common findings in a speech-language therapy videofluoroscopy clinic. Fluoroscopic screening involving oropharynx alone fails to identify these patients. Oesophageal screening as an adjunct to videofluoroscopy is gaining popularity. Yet currently, little is known about the reliability of speech and…

  6. Visual hallucinatory syndromes and the anatomy of the visual brain.

    PubMed

    Santhouse, A M; Howard, R J; ffytche, D H

    2000-10-01

    We have set out to identify phenomenological correlates of cerebral functional architecture within Charles Bonnet syndrome (CBS) hallucinations by looking for associations between specific hallucination categories. Thirty-four CBS patients were examined with a structured interview/questionnaire to establish the presence of 28 different pathological visual experiences. Associations between categories of pathological experience were investigated by an exploratory factor analysis. Twelve of the pathological experiences partitioned into three segregated syndromic clusters. The first cluster consisted of hallucinations of extended landscape scenes and small figures in costumes with hats; the second, hallucinations of grotesque, disembodied and distorted faces with prominent eyes and teeth; and the third, visual perseveration and delayed palinopsia. The three visual psycho-syndromes mirror the segregation of hierarchical visual pathways into streams and suggest a novel theoretical framework for future research into the pathophysiology of neuropsychiatric syndromes.

  7. How Visual Is the Visual Cortex? Comparing Connectional and Functional Fingerprints between Congenitally Blind and Sighted Individuals.

    PubMed

    Wang, Xiaoying; Peelen, Marius V; Han, Zaizhu; He, Chenxi; Caramazza, Alfonso; Bi, Yanchao

    2015-09-09

    Classical animal visual deprivation studies and human neuroimaging studies have shown that visual experience plays a critical role in shaping the functionality and connectivity of the visual cortex. Interestingly, recent studies have additionally reported circumscribed regions in the visual cortex in which functional selectivity was remarkably similar in individuals with and without visual experience. Here, by directly comparing resting-state and task-based fMRI data in congenitally blind and sighted human subjects, we obtained large-scale continuous maps of the degree to which connectional and functional "fingerprints" of ventral visual cortex depend on visual experience. We found a close agreement between connectional and functional maps, pointing to a strong interdependence of connectivity and function. Visual experience (or the absence thereof) had a pronounced effect on the resting-state connectivity and functional response profile of occipital cortex and the posterior lateral fusiform gyrus. By contrast, connectional and functional fingerprints in the anterior medial and posterior lateral parts of the ventral visual cortex were statistically indistinguishable between blind and sighted individuals. These results provide a large-scale mapping of the influence of visual experience on the development of both functional and connectivity properties of visual cortex, which serves as a basis for the formulation of new hypotheses regarding the functionality and plasticity of specific subregions. Significance statement: How is the functionality and connectivity of the visual cortex shaped by visual experience? By directly comparing resting-state and task-based fMRI data in congenitally blind and sighted subjects, we obtained large-scale continuous maps of the degree to which connectional and functional "fingerprints" of ventral visual cortex depend on visual experience. In addition to revealing regions that are strongly dependent on visual experience (early visual

  8. Experience-dependent emergence of beta and gamma band oscillations in the primary visual cortex during the critical period

    PubMed Central

    Chen, Guang; Rasch, Malte J.; Wang, Ran; Zhang, Xiao-hui

    2015-01-01

    Neural oscillatory activities have been shown to play important roles in neural information processing and the shaping of circuit connections during development. However, it remains unknown whether and how specific neural oscillations emerge during a postnatal critical period (CP), in which neuronal connections are most substantially modified by neural activity and experience. By recording local field potentials (LFPs) and single unit activity in developing primary visual cortex (V1) of head-fixed awake mice, we here demonstrate an emergence of characteristic oscillatory activities during the CP. From the pre-CP to CP, the peak frequency of spontaneous fast oscillatory activities shifts from the beta band (15–35 Hz) to the gamma band (40–70 Hz), accompanied by a decrease of cross-frequency coupling (CFC) and broadband spike-field coherence (SFC). Moreover, visual stimulation induced a large increase of beta-band activity but a reduction of gamma-band activity specifically from the CP onwards. Dark rearing of animals from the birth delayed this emergence of oscillatory activities during the CP, suggesting its dependence on early visual experience. These findings suggest that the characteristic neuronal oscillatory activities emerged specifically during the CP may represent as neural activity trait markers for the experience-dependent maturation of developing visual cortical circuits. PMID:26648548

  9. Visual function at 11 years of age in preterm-born children with and without fetal brain sparing.

    PubMed

    Kok, Joke H; Prick, Liesbeth; Merckel, Elly; Everhard, Yolande; Verkerk, Gijs J Q; Scherjon, Sicco A

    2007-06-01

    We have demonstrated earlier an accelerated maturation of the visual evoked potential in the first year of life in preterm infants with antenatal brain sparing. We have now assessed visual functioning at 11 years of age in the same cohort and compared the groups with and without brain sparing. One hundred sixteen survivors included in a study on the outcome of preterm infants born at <33 weeks' gestation with and without fetal brain sparing and admitted to the NICU were followed extensively. Ninety-eight infants (85%) were again assessed at 11 years of age. Data were available for fetal Doppler measurements indicating brain sparing, neonatal cerebral ultrasound scanning, and developmental outcome in the first 5 years. Mean birth weight was 1303 g; mean gestational age was 29.8 weeks. The infants were divided into 2 groups with and without brain sparing. Visual functioning was estimated by measuring visual acuity, visual fields, eye position, and binocular function and by visual motor tests. Six percent of the children were found to have a visual acuity of <0.8, 12% had strabismus, and 14% to 46% showed abnormal results on the visual motor tests. No statistical differences were found between the 2 groups. However, children with severe cerebral ultrasound diagnoses in the neonatal period were found to have significantly more abnormalities on visual functioning and lower scores on visual motor tests than children without these morbidities. Children with fetal brain sparing do not demonstrate a different development of their visual functioning at late school age. However, an abnormal cerebral ultrasound in the neonatal period is associated with impaired visual function in later life.

  10. Perceived functional impact of abnormal facial appearance.

    PubMed

    Rankin, Marlene; Borah, Gregory L

    2003-06-01

    Functional facial deformities are usually described as those that impair respiration, eating, hearing, or speech. Yet facial scars and cutaneous deformities have a significant negative effect on social functionality that has been poorly documented in the scientific literature. Insurance companies are declining payments for reconstructive surgical procedures for facial deformities caused by congenital disabilities and after cancer or trauma operations that do not affect mechanical facial activity. The purpose of this study was to establish a large, sample-based evaluation of the perceived social functioning, interpersonal characteristics, and employability indices for a range of facial appearances (normal and abnormal). Adult volunteer evaluators (n = 210) provided their subjective perceptions based on facial physical appearance, and an analysis of the consequences of facial deformity on parameters of preferential treatment was performed. A two-group comparative research design rated the differences among 10 examples of digitally altered facial photographs of actual patients among various age and ethnic groups with "normal" and "abnormal" congenital deformities or posttrauma scars. Photographs of adult patients with observable congenital and posttraumatic deformities (abnormal) were digitally retouched to eliminate the stigmatic defects (normal). The normal and abnormal photographs of identical patients were evaluated by the large sample study group on nine parameters of social functioning, such as honesty, employability, attractiveness, and effectiveness, using a visual analogue rating scale. Patients with abnormal facial characteristics were rated as significantly less honest (p = 0.007), less employable (p = 0.001), less trustworthy (p = 0.01), less optimistic (p = 0.001), less effective (p = 0.02), less capable (p = 0.002), less intelligent (p = 0.03), less popular (p = 0.001), and less attractive (p = 0.001) than were the same patients with normal facial

  11. Visualization and recommendation of large image collections toward effective sensemaking

    NASA Astrophysics Data System (ADS)

    Gu, Yi; Wang, Chaoli; Nemiroff, Robert; Kao, David; Parra, Denis

    2016-03-01

    In our daily lives, images are among the most commonly found data which we need to handle. We present iGraph, a graph-based approach for visual analytics of large image collections and their associated text information. Given such a collection, we compute the similarity between images, the distance between texts, and the connection between image and text to construct iGraph, a compound graph representation which encodes the underlying relationships among these images and texts. To enable effective visual navigation and comprehension of iGraph with tens of thousands of nodes and hundreds of millions of edges, we present a progressive solution that offers collection overview, node comparison, and visual recommendation. Our solution not only allows users to explore the entire collection with representative images and keywords but also supports detailed comparison for understanding and intuitive guidance for navigation. The visual exploration of iGraph is further enhanced with the implementation of bubble sets to highlight group memberships of nodes, suggestion of abnormal keywords or time periods based on text outlier detection, and comparison of four different recommendation solutions. For performance speedup, multiple graphics processing units and central processing units are utilized for processing and visualization in parallel. We experiment with two image collections and leverage a cluster driving a display wall of nearly 50 million pixels. We show the effectiveness of our approach by demonstrating experimental results and conducting a user study.

  12. Monitoring Processes in Visual Search Enhanced by Professional Experience: The Case of Orange Quality-Control Workers

    PubMed Central

    Visalli, Antonino; Vallesi, Antonino

    2018-01-01

    Visual search tasks have often been used to investigate how cognitive processes change with expertise. Several studies have shown visual experts' advantages in detecting objects related to their expertise. Here, we tried to extend these findings by investigating whether professional search experience could boost top-down monitoring processes involved in visual search, independently of advantages specific to objects of expertise. To this aim, we recruited a group of quality-control workers employed in citrus farms. Given the specific features of this type of job, we expected that the extensive employment of monitoring mechanisms during orange selection could enhance these mechanisms even in search situations in which orange-related expertise is not suitable. To test this hypothesis, we compared performance of our experimental group and of a well-matched control group on a computerized visual search task. In one block the target was an orange (expertise target) while in the other block the target was a Smurfette doll (neutral target). The a priori hypothesis was to find an advantage for quality-controllers in those situations in which monitoring was especially involved, that is, when deciding the presence/absence of the target required a more extensive inspection of the search array. Results were consistent with our hypothesis. Quality-controllers were faster in those conditions that extensively required monitoring processes, specifically, the Smurfette-present and both target-absent conditions. No differences emerged in the orange-present condition, which resulted to mainly rely on bottom-up processes. These results suggest that top-down processes in visual search can be enhanced through immersive real-life experience beyond visual expertise advantages. PMID:29497392

  13. Quantifying the abnormal hemodynamics of sickle cell anemia

    NASA Astrophysics Data System (ADS)

    Lei, Huan; Karniadakis, George

    2012-02-01

    Sickle red blood cells (SS-RBC) exhibit heterogeneous morphologies and abnormal hemodynamics in deoxygenated states. A multi-scale model for SS-RBC is developed based on the Dissipative Particle Dynamics (DPD) method. Different cell morphologies (sickle, granular, elongated shapes) typically observed in deoxygenated states are constructed and quantified by the Asphericity and Elliptical shape factors. The hemodynamics of SS-RBC suspensions is studied in both shear and pipe flow systems. The flow resistance obtained from both systems exhibits a larger value than the healthy blood flow due to the abnormal cell properties. Moreover, SS-RBCs exhibit abnormal adhesive interactions with both the vessel endothelium cells and the leukocytes. The effect of the abnormal adhesive interactions on the hemodynamics of sickle blood is investigated using the current model. It is found that both the SS-RBC - endothelium and the SS-RBC - leukocytes interactions, can potentially trigger the vicious ``sickling and entrapment'' cycles, resulting in vaso-occlusion phenomena widely observed in micro-circulation experiments.

  14. Neonatal Brain Abnormalities and Memory and Learning Outcomes at 7 Years in Children Born Very Preterm

    PubMed Central

    Omizzolo, Cristina; Scratch, Shannon E; Stargatt, Robyn; Kidokoro, Hiroyuki; Thompson, Deanne K; Lee, Katherine J; Cheong, Jeanie; Neil, Jeffrey; Inder, Terrie E; Doyle, Lex W; Anderson, Peter J

    2014-01-01

    Using prospective longitudinal data from 198 very preterm and 70 full term children, this study characterised the memory and learning abilities of very preterm children at 7 years of age in both verbal and visual domains. The relationship between the extent of brain abnormalities on neonatal magnetic resonance imaging (MRI) and memory and learning outcomes at 7 years of age in very preterm children was also investigated. Neonatal MRI scans were qualitatively assessed for global, white-matter, cortical grey-matter, deep grey-matter, and cerebellar abnormalities. Very preterm children performed less well on measures of immediate memory, working memory, long-term memory, and learning compared with term born controls. Neonatal brain abnormalities, and in particular deep grey matter abnormality, were associated with poorer memory and learning performance at 7 years in very preterm children, especially global, white-matter, grey-matter and cerebellar abnormalities. Findings support the importance of cerebral neonatal pathology for predicting later memory and learning function. PMID:23805915

  15. Color vision abnormality as an initial presentation of the complete type of congenital stationary night blindness.

    PubMed

    Tan, Xue; Aoki, Aya; Yanagi, Yasuo

    2013-01-01

    Patients with the complete form of congenital stationary night blindness (CSNB) often have reduced visual acuity, myopia, impaired night vision, and sometimes nystagmus and strabismus, however, they seldom complain of color vision abnormality. A 17-year-old male who was at technical school showed abnormalities in the color perception test for employment, and was referred to our hospital for a detailed examination. He had no family history of color vision deficiency and no other symptoms. During the initial examination, his best-corrected visual acuity was 1.2 in both eyes. His fundus showed no abnormalities except for somewhat yellowish reflex in the fovea of both eyes. Electroretinogram (ERG) showed a good response in cone ERG and 30 Hz flicker ERG, however, the bright flash, mixed rod and cone ERG showed a negative type with a reduced b-wave (positive deflection). There was no response in the rod ERG, either. From the findings of the typical ERG, the patient was diagnosed with complete congenital stationary night blindness. This case underscores the importance of ERG in order to diagnose the cause of a color vision anomaly.

  16. Factors Related to Impaired Visual Orienting Behavior in Children with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Boot, F. H.; Pel, J .J. M.; Evenhuis, H. M.; van der Steen, J.

    2012-01-01

    It is generally assumed that children with intellectual disabilities (ID) have an increased risk of impaired visual information processing due to brain damage or brain development disorder. So far little evidence has been presented to support this assumption. Abnormal visual orienting behavior is a sensitive tool to evaluate impaired visual…

  17. Abnormal Uterine Bleeding

    MedlinePlus

    ... abnormal uterine bleeding? Abnormal uterine bleeding is any heavy or unusual bleeding from the uterus (through your ... one symptom of abnormal uterine bleeding. Having extremely heavy bleeding during your period can also be considered ...

  18. The Importance of Visual Experience, Gender, and Emotion in the Assessment of an Assistive Tactile Mouse.

    PubMed

    Brayda, Luca; Campus, Claudio; Memeo, Mariacarla; Lucagrossi, Laura

    2015-01-01

    Tactile maps are efficient tools to improve spatial understanding and mobility skills of visually impaired people. Their limited adaptability can be compensated with haptic devices which display graphical information, but their assessment is frequently limited to performance-based metrics only which can hide potential spatial abilities in O&M protocols. We assess a low-tech tactile mouse able to deliver three-dimensional content considering how performance, mental workload, behavior, and anxiety status vary with task difficulty and gender in congenitally blind, late blind, and sighted subjects. Results show that task difficulty coherently modulates the efficiency and difficulty to build mental maps, regardless of visual experience. Although exhibiting attitudes that were similar and gender-independent, the females had lower performance and higher cognitive load, especially when congenitally blind. All groups showed a significant decrease in anxiety after using the device. Tactile graphics with our device seems therefore to be applicable with different visual experiences, with no negative emotional consequences of mentally demanding spatial tasks. Going beyond performance-based assessment, our methodology can help with better targeting technological solutions in orientation and mobility protocols.

  19. 3D PATTERN OF BRAIN ABNORMALITIES IN FRAGILE X SYNDROME VISUALIZED USING TENSOR-BASED MORPHOMETRY

    PubMed Central

    Lee, Agatha D.; Leow, Alex D.; Lu, Allen; Reiss, Allan L.; Hall, Scott; Chiang, Ming-Chang; Toga, Arthur W.; Thompson, Paul M.

    2007-01-01

    Fragile X syndrome (FraX), a genetic neurodevelopmental disorder, results in impaired cognition with particular deficits in executive function and visuo-spatial skills. Here we report the first detailed 3D maps of the effects of the Fragile X mutation on brain structure, using tensor-based morphometry. TBM visualizes structural brain deficits automatically, without time-consuming specification of regions-of-interest. We compared 36 subjects with FraX (age: 14.66+/−1.58SD, 18 females/18 males), and 33 age-matched healthy controls (age: 14.67+/−2.2SD, 17 females/16 males), using high-dimensional elastic image registration. All 69 subjects' 3D T1-weighted brain MRIs were spatially deformed to match a high-resolution single-subject average MRI scan in ICBM space, whose geometry was optimized to produce a minimal deformation target. Maps of the local Jacobian determinant (expansion factor) were computed from the deformation fields. Statistical maps showed increased caudate (10% higher; p=0.001) and lateral ventricle volumes (19% higher; p=0.003), and trend-level parietal and temporal white matter excesses (10% higher locally; p=0.04). In affected females, volume abnormalities correlated with reduction in systemically measured levels of the fragile X mental retardation protein (FMRP; Spearman's r<−0.5 locally). Decreased FMRP correlated with ventricular expansion (p=0.042; permutation test), and anterior cingulate tissue reductions (p=0.0026; permutation test) supporting theories that FMRP is required for normal dendritic pruning in fronto-striatal-limbic pathways. No sex differences were found; findings were confirmed using traditional volumetric measures in regions of interest. Deficit patterns were replicated using Lie group statistics optimized for tensor-valued data. Investigation of how these anomalies emerge over time will accelerate our understanding of FraX and its treatment. PMID:17161622

  20. A simple infrared-augmented digital photography technique for detection of pupillary abnormalities.

    PubMed

    Shazly, Tarek A; Bonhomme, G R

    2015-03-01

    The purpose of the study was to describe a simple infrared photography technique to aid in the diagnosis and documentation of pupillary abnormalities. An unmodified 12-megapixel "point and shoot" digital camera was used to obtain binocular still photos and videos under different light conditions with near-infrared illuminating frames. The near-infrared light of 850 nm allows the capture of clear pupil images in both dim and bright light conditions. It also allows easy visualization of the pupil despite pigmented irides by augmenting the contrast between the iris and the pupil. The photos and videos obtained illustrated a variety of pupillary abnormalities using the aforementioned technique. This infrared-augmented photography technique supplements medical education, and aids in the more rapid detection, diagnosis, and documentation of a wide spectrum of pupillary abnormalities. Its portability and ease of use with minimal training complements the education of trainees and facilitates the establishment of difficult diagnoses.

  1. Sleep abnormalities in children with Dravet syndrome.

    PubMed

    Dhamija, Radhika; Erickson, Maia K; St Louis, Erik K; Wirrell, Elaine; Kotagal, Suresh

    2014-05-01

    Mutations in the voltage-gated sodium channel SCN1A gene are responsible for the majority of Dravet syndrome cases. There is evidence that the Nav1.1 channel coded by the SCN1A gene is involved in sleep regulation. We evaluated sleep abnormalities in children with Dravet syndrome using nocturnal polysomnography. We identified six children at our institution with genetically confirmed Dravet syndrome who had also undergone formal sleep consultation with nocturnal polysomnography. Indications for polysomnography were parental concern of daytime fatigue or sleepiness, hyperactivity, inattention, disruptive behavior, nighttime awakenings, or nocturnal seizures. Sleep studies were scored according to guidelines of the American Academy of Sleep Medicine and non-rapid eye movement cyclic alternating pattern was visually identified and scored according to established methods. The mean age of the subjects at the time of polysomnography was 6 years. Standard polysomnography did not show any consistent abnormalities in the obstructive or central apnea index, arousal index, sleep efficiency, or architecture. Cyclic alternating pattern analysis on five patients showed an increased mean rate of 50.3% (vs 31% to 34% in neurological normal children) with a mild increase in A1 subtype of 89.4% (vs 84.5%). A2/A3 subtype (5.3% vs 7.3%) and B phase duration (22.4 vs 24.7 seconds) were similar to previously reported findings in neurologically normal children. Despite parental concerns for sleep disturbance in patients with Dravet syndrome, we could not identify abnormalities in sleep macroarchitecture. Non-rapid eye movement sleep microarchitecture was, however, abnormal, with increased A1 subtype, somewhat resembling a tracé alternant pattern of neonates and possibly suggestive of cortical synaptic immaturity in Dravet syndrome. Larger studies are needed to replicate these results. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. The Role of Visual Experience on the Representation and Updating of Novel Haptic Scenes

    ERIC Educational Resources Information Center

    Pasqualotto, Achille; Newell, Fiona N.

    2007-01-01

    We investigated the role of visual experience on the spatial representation and updating of haptic scenes by comparing recognition performance across sighted, congenitally and late blind participants. We first established that spatial updating occurs in sighted individuals to haptic scenes of novel objects. All participants were required to…

  3. Priming and the guidance by visual and categorical templates in visual search.

    PubMed

    Wilschut, Anna; Theeuwes, Jan; Olivers, Christian N L

    2014-01-01

    Visual search is thought to be guided by top-down templates that are held in visual working memory. Previous studies have shown that a search-guiding template can be rapidly and strongly implemented from a visual cue, whereas templates are less effective when based on categorical cues. Direct visual priming from cue to target may underlie this difference. In two experiments we first asked observers to remember two possible target colors. A postcue then indicated which of the two would be the relevant color. The task was to locate a briefly presented and masked target of the cued color among irrelevant distractor items. Experiment 1 showed that overall search accuracy improved more rapidly on the basis of a direct visual postcue that carried the target color, compared to a neutral postcue that pointed to the memorized color. However, selectivity toward the target feature, i.e., the extent to which observers searched selectively among items of the cued vs. uncued color, was found to be relatively unaffected by the presence of the visual signal. In Experiment 2 we compared search that was based on either visual or categorical information, but now controlled for direct visual priming. This resulted in no differences in overall performance nor selectivity. Altogether the results suggest that perceptual processing of visual search targets is facilitated by priming from visual cues, whereas attentional selectivity is enhanced by a working memory template that can formed from both visual and categorical input. Furthermore, if the priming is controlled for, categorical- and visual-based templates similarly enhance search guidance.

  4. Cross-species 3D virtual reality toolbox for visual and cognitive experiments.

    PubMed

    Doucet, Guillaume; Gulli, Roberto A; Martinez-Trujillo, Julio C

    2016-06-15

    Although simplified visual stimuli, such as dots or gratings presented on homogeneous backgrounds, provide strict control over the stimulus parameters during visual experiments, they fail to approximate visual stimulation in natural conditions. Adoption of virtual reality (VR) in neuroscience research has been proposed to circumvent this problem, by combining strict control of experimental variables and behavioral monitoring within complex and realistic environments. We have created a VR toolbox that maximizes experimental flexibility while minimizing implementation costs. A free VR engine (Unreal 3) has been customized to interface with any control software via text commands, allowing seamless introduction into pre-existing laboratory data acquisition frameworks. Furthermore, control functions are provided for the two most common programming languages used in visual neuroscience: Matlab and Python. The toolbox offers milliseconds time resolution necessary for electrophysiological recordings and is flexible enough to support cross-species usage across a wide range of paradigms. Unlike previously proposed VR solutions whose implementation is complex and time-consuming, our toolbox requires minimal customization or technical expertise to interface with pre-existing data acquisition frameworks as it relies on already familiar programming environments. Moreover, as it is compatible with a variety of display and input devices, identical VR testing paradigms can be used across species, from rodents to humans. This toolbox facilitates the addition of VR capabilities to any laboratory without perturbing pre-existing data acquisition frameworks, or requiring any major hardware changes. Copyright © 2016 Z. All rights reserved.

  5. Abnormal Magnetic Field Effects on Electrogenerated Chemiluminescence

    NASA Astrophysics Data System (ADS)

    Pan, Haiping; Shen, Yan; Wang, Hongfeng; He, Lei; Hu, Bin

    2015-03-01

    We report abnormal magnetic field effects on electrogenerated chemiluminescence (MFEECL) based on triplet emission from the Ru(bpy)3Cl2-TPrA electrochemical system: the appearance of MFEECL after magnetic field ceases. In early studies the normal MFEECL have been observed from electrochemical systems during the application of magnetic field. Here, the abnormal MFEECL suggest that the activated charge-transfer [Ru(bpy)33+ … TPrA•] complexes may become magnetized in magnetic field and experience a long magnetic relaxation after removing magnetic field. Our analysis indicates that the magnetic relaxation can gradually increase the density of charge-transfer complexes within reaction region due to decayed magnetic interactions, leading to a positive component in the abnormal MFEECL. On the other hand, the magnetic relaxation facilitates an inverse conversion from triplets to singlets within charge-transfer complexes. The inverse triplet --> singlet conversion reduces the density of triplet light-emitting states through charge-transfer complexes and gives rise to a negative component in the abnormal MFEECL. The combination of positive and negative components can essentially lead to a non-monotonic profile in the abnormal MFEECL after ceasing magnetic field. Nevertheless, our experimental studies may reveal un-usual magnetic behaviors with long magnetic relaxation from the activated charge-transfer [Ru(bpy)33+ … TPrA•] complexes in solution at room temperature.

  6. From genes to brain oscillations: is the visual pathway the epigenetic clue to schizophrenia?

    PubMed

    González-Hernández, J A; Pita-Alcorta, C; Cedeño, I R

    2006-01-01

    Molecular data and gene expression data and recently mitochondrial genes and possible epigenetic regulation by non-coding genes is revolutionizing our views on schizophrenia. Genes and epigenetic mechanisms are triggered by cell-cell interaction and by external stimuli. A number of recent clinical and molecular observations indicate that epigenetic factors may be operational in the origin of the illness. Based on the molecular insights, gene expression profiles and epigenetic regulation of gene, we went back to the neurophysiology (brain oscillations) and found a putative role of the visual experiences (i.e. visual stimuli) as epigenetic factor. The functional evidences provided here, establish a direct link between the striate and extrastriate unimodal visual cortex and the neurobiology of the schizophrenia. This result support the hypothesis that 'visual experience' has a potential role as epigenetic factor and contribute to trigger and/or to maintain the progression of the schizophrenia. In this case, candidate genes sensible for the visual 'insult' may be located within the visual cortex including associative areas, while the integrity of the visual pathway before reaching the primary visual cortex is preserved. The same effect can be perceived if target genes are localised within the visual pathway, which actually, is more sensitive for 'insult' during the early life than the cortex per se. If this process affects gene expression at these sites a stably sensory specific 'insult', i.e. distorted visual information, is entering the visual system and expanded to fronto-temporo-parietal multimodal areas even from early maturation periods. The difference in the timing of postnatal neuroanatomical events between such areas and the primary visual cortex in humans (with the formers reaching the same development landmarks later in life than the latter) is 'optimal' to establish an abnormal 'cell- communication' mediated by the visual system that may further interfere

  7. Basal Ganglia Shape Abnormalities in the Unaffected Siblings of Schizophrenia Patients

    PubMed Central

    Mamah, Daniel; Harms, Michael P.; Wang, Lei; Barch, Deanna; Thompson, Paul; Kim, Jaeyun; Miller, Michael I.; Csernansky, John G.

    2008-01-01

    Objective Abnormalities of basal ganglia structure in schizophrenia have been attributed to the effects of antipsychotic drugs. Our aim was to test the hypothesis that abnormalities of basal ganglia structure are intrinsic features of schizophrenia, by assessing basal ganglia volume and shape in the unaffected siblings of schizophrenia subjects. Method The study involved 25 pairs of schizophrenia subjects and their unaffected siblings and 40 pairs of healthy controls and their siblings. Large deformation, high-dimensional brain mapping was used to obtain surface representations of the caudate, putamen, and globus pallidus. Surfaces were derived from transformations of anatomical templates and shapes were analyzed using reduced-dimensional measures of surface variability (i.e. principal components and canonical analysis). Canonical functions were derived using schizophrenia and control groups, and were then used to compare shapes in the sibling groups. To visualize shape differences, maps of the estimated surface displacement between groups were created. Results In the caudate, putamen and globus pallidus, the degree of shape abnormality observed in the siblings of the schizophrenia subjects was intermediate between the schizophrenia subjects and the controls. In the schizophrenia subjects, significant correlations were observed between measures of caudate, putamen and globus pallidus structure and the selected measures of lifetime psychopathology. Conclusions Attenuated abnormalities of basal ganglia structure are present in the unaffected siblings of schizophrenia subjects. This finding implies that basal ganglia structural abnormalities observed in subjects with schizophrenia are at least in part an intrinsic feature of the illness. PMID:18295189

  8. Objective functional visual outcomes of cataract surgery in patients with good preoperative visual acuity

    PubMed Central

    Zhu, X; Ye, H; He, W; Yang, J; Dai, J; Lu, Y

    2017-01-01

    Purpose To explore the objective functional visual outcomes of cataract surgery in patients with good preoperative visual acuity. Methods We enrolled 130 cataract patients whose best-corrected visual acuity (BCVA) was 20/40 or better preoperatively. Objective visual functions were evaluated with a KR-1W analyzer before and at 1 month after cataract surgery. Results The nuclear (N), cortical (C), and N+C groups had very high preoperative ocular and internal total high-order aberrations (HOAs), coma, and abnormal spherical aberrations. At 1 month after cataract surgery, in addition to the remarkable increase of both uncorrected visual acuity and BCVA, both ocular and internal HOAs in the three groups decreased significantly after cataract surgery (all P<0.05). Point spread function and modulation transfer functions were also improved significantly in these patients (all P<0.05). Conclusions The objective functional vision of patients with 20/40 or better preoperative BCVA improved significantly after cataract surgery. This finding shows that the arbitrary threshold of BCVA worse than 20/40 in China cannot always be used to determine who will benefit from cataract surgery. PMID:27858933

  9. Simulated in vivo Electrophysiology Experiments Provide Previously Inaccessible Insights into Visual Physiology

    PubMed Central

    Quiroga, Maria del Mar; Price, Nicholas SC

    2016-01-01

    Lecture content and practical laboratory classes are ideally complementary. However, the types of experiments that have led to our detailed understanding of sensory neuroscience are often not amenable to classroom experimentation as they require expensive equipment, time-consuming surgeries, specialized experimental techniques, and the use of animals. While sometimes feasible in small group teaching, these experiments are not suitable for large cohorts of students. Previous attempts to expose students to sensory neuroscience experiments include: the use of electrophysiology preparations in invertebrates, data-driven simulations that do not replicate the experience of conducting an experiment, or simply observing an experiment in a research laboratory. We developed an online simulation of a visual neuroscience experiment in which extracellular recordings are made from a motion sensitive neuron. Students have control over stimulation parameters (direction and contrast) and can see and hear the action potential responses to stimuli as they are presented. The simulation provides an intuitive way for students to gain insight into neurophysiology, including experimental design, data collection and data analysis. Our simulation allows large cohorts of students to cost-effectively “experience” the results of animal research without ethical concerns, to be exposed to realistic data variability, and to develop their understanding of how sensory neuroscience experiments are conducted. PMID:27980465

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

    ERIC Educational Resources Information Center

    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…

  11. Sensitivity of visual evoked potentials and spectral domain optical coherence tomography in early relapsing remitting multiple sclerosis.

    PubMed

    Behbehani, Raed; Ahmed, Samar; Al-Hashel, Jasem; Rousseff, Rossen T; Alroughani, Raed

    2017-02-01

    Visual evoked potentials and spectral-domain optical coherence tomography are common ancillary studies that assess the visual pathways from a functional and structural aspect, respectively. To compare prevalence of abnormalities of Visual evoked potentials (VEP) and spectral-domain optical coherence tomography (SDOCT) in patients with relapsing remitting multiple sclerosis (RRMS). A cross-sectional study of 100 eyes with disease duration of less than 5 years since the diagnosis. Correlation between retinal nerve fiber layer and ganglion-cell/inner plexiform layer with pattern-reversal visual evoked potentials amplitude and latency and contrast sensitivity was performed. The prevalence of abnormalities in pattern-reversal visual VEP was 56% while that of SOCT was 48% in all eyes. There was significant negative correlations between the average RNFL (r=-0.34, p=0.001) and GCIPL (r=-0.39, p<0.001) with VEP latency. In eyes with prior optic neuritis, a significant negative correlation was seen between average RNFL (r=-0.33, p=0.037) and GCIPL (r=-0.40, p=0.010) with VEP latency. We have found higher prevalence of VEP abnormalities than SCOCT in early relapsing-remitting multiple sclerosis. This suggests that VEP has a higher sensitivity for detecting lesions of the visual pathway in patients with early RRMS. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. The role of visuohaptic experience in visually perceived depth.

    PubMed

    Ho, Yun-Xian; Serwe, Sascha; Trommershäuser, Julia; Maloney, Laurence T; Landy, Michael S

    2009-06-01

    Berkeley suggested that "touch educates vision," that is, haptic input may be used to calibrate visual cues to improve visual estimation of properties of the world. Here, we test whether haptic input may be used to "miseducate" vision, causing observers to rely more heavily on misleading visual cues. Human subjects compared the depth of two cylindrical bumps illuminated by light sources located at different positions relative to the surface. As in previous work using judgments of surface roughness, we find that observers judge bumps to have greater depth when the light source is located eccentric to the surface normal (i.e., when shadows are more salient). Following several sessions of visual judgments of depth, subjects then underwent visuohaptic training in which haptic feedback was artificially correlated with the "pseudocue" of shadow size and artificially decorrelated with disparity and texture. Although there were large individual differences, almost all observers demonstrated integration of haptic cues during visuohaptic training. For some observers, subsequent visual judgments of bump depth were unaffected by the training. However, for 5 of 12 observers, training significantly increased the weight given to pseudocues, causing subsequent visual estimates of shape to be less veridical. We conclude that haptic information can be used to reweight visual cues, putting more weight on misleading pseudocues, even when more trustworthy visual cues are available in the scene.

  13. Feature-Based Memory-Driven Attentional Capture: Visual Working Memory Content Affects Visual Attention

    ERIC Educational Resources Information Center

    Olivers, Christian N. L.; Meijer, Frank; Theeuwes, Jan

    2006-01-01

    In 7 experiments, the authors explored whether visual attention (the ability to select relevant visual information) and visual working memory (the ability to retain relevant visual information) share the same content representations. The presence of singleton distractors interfered more strongly with a visual search task when it was accompanied by…

  14. A novel computational model to probe visual search deficits during motor performance

    PubMed Central

    Singh, Tarkeshwar; Fridriksson, Julius; Perry, Christopher M.; Tryon, Sarah C.; Ross, Angela; Fritz, Stacy

    2016-01-01

    Successful execution of many motor skills relies on well-organized visual search (voluntary eye movements that actively scan the environment for task-relevant information). Although impairments of visual search that result from brain injuries are linked to diminished motor performance, the neural processes that guide visual search within this context remain largely unknown. The first objective of this study was to examine how visual search in healthy adults and stroke survivors is used to guide hand movements during the Trail Making Test (TMT), a neuropsychological task that is a strong predictor of visuomotor and cognitive deficits. Our second objective was to develop a novel computational model to investigate combinatorial interactions between three underlying processes of visual search (spatial planning, working memory, and peripheral visual processing). We predicted that stroke survivors would exhibit deficits in integrating the three underlying processes, resulting in deteriorated overall task performance. We found that normal TMT performance is associated with patterns of visual search that primarily rely on spatial planning and/or working memory (but not peripheral visual processing). Our computational model suggested that abnormal TMT performance following stroke is associated with impairments of visual search that are characterized by deficits integrating spatial planning and working memory. This innovative methodology provides a novel framework for studying how the neural processes underlying visual search interact combinatorially to guide motor performance. NEW & NOTEWORTHY Visual search has traditionally been studied in cognitive and perceptual paradigms, but little is known about how it contributes to visuomotor performance. We have developed a novel computational model to examine how three underlying processes of visual search (spatial planning, working memory, and peripheral visual processing) contribute to visual search during a visuomotor task. We

  15. Abnormal intrinsic functional hubs in alcohol dependence: evidence from a voxelwise degree centrality analysis.

    PubMed

    Luo, Xiaoping; Guo, Linghong; Dai, Xi-Jian; Wang, Qinglai; Zhu, Wenzhong; Miao, Xinjun; Gong, Honghan

    2017-01-01

    To explore the abnormal intrinsic functional hubs in alcohol dependence using voxelwise degree centrality analysis approach, and their relationships with clinical features. Twenty-four male alcohol dependence subjects free of medicine (mean age, 50.21±9.62 years) and 24 age- and education-matched male healthy controls (mean age, 50.29±8.92 years) were recruited. The alcohol use disorders identification test and the severity of alcohol dependence questionnaire (SADQ) were administered to assess the severity of alcohol craving. Voxelwise degree centrality approach was used to assess the abnormal intrinsic functional hubs features in alcohol dependence. Simple linear regression analysis was performed to investigate the relationships between the clinical features and abnormal intrinsic functional hubs. Compared with healthy controls, alcohol dependence subjects exhibited significantly different degree centrality values in widespread left lateralization brain areas, including higher degree centrality values in the left precentral gyrus (BA 6), right hippocampus (BA 35, 36), and left orbitofrontal cortex (BA 11) and lower degree centrality values in the left cerebellum posterior lobe, bilateral secondary visual network (BA 18), and left precuneus (BA 7, 19). SADQ revealed a negative linear correlation with the degree centrality value in the left precentral gyrus ( R 2 =0.296, P =0.006). The specific abnormal intrinsic functional hubs appear to be disrupted by alcohol intoxication, which implicates at least three principal neural systems: including cerebellar, executive control, and visual cortex, which may further affect the normal motor behavior such as an explicit type of impaired driving behavior. These findings expand our understanding of the functional characteristics of alcohol dependence and may provide a new insight into the understanding of the dysfunction and pathophysiology of alcohol dependence.

  16. Experience with Using Multiple Types of Visual Educational Tools during Problem-Based Learning.

    PubMed

    Kang, Bong Jin

    2012-06-01

    This study describes the experience of using multiple types of visual educational tools in the setting of problem-based learning (PBL). The author intends to demonstrate their roles in diverse and efficient ways of clinical reasoning and problem solving. Visual educational tools were introduced in a lecture that included their various types, possible benefits, and some examples. Each group made one mechanistic case diagram per week, and each student designed one diagnostic schema or therapeutic algorithm per week, based on their learning issues. The students were also told to provide commentary, which was intended to give insights into their truthfulness. Subsequently, the author administered a questionnaire about the usefulness and weakness of visual educational tools and the difficulties with performing the work. Also, the qualities of the products were assessed by the author. There were many complaints about the adequacy of the introduction of visual educational tools, also revealed by the many initial inappropriate types of products. However, the exercise presentation in the first week improved the level of understanding regarding their purposes and the method of design. In general, students agreed on the benefits of their help in providing a deep understanding of the cases and the possibility of solving clinical problems efficiently. The commentary was helpful in evaluating the truthfulness of their efforts. Students gave suggestions for increasing the percentage of their scores, considering the efforts. Using multiple types of visual educational tools during PBL can be useful in understanding the diverse routes of clinical reasoning and clinical features.

  17. Neonatal brain abnormalities and memory and learning outcomes at 7 years in children born very preterm.

    PubMed

    Omizzolo, Cristina; Scratch, Shannon E; Stargatt, Robyn; Kidokoro, Hiroyuki; Thompson, Deanne K; Lee, Katherine J; Cheong, Jeanie; Neil, Jeffrey; Inder, Terrie E; Doyle, Lex W; Anderson, Peter J

    2014-01-01

    Using prospective longitudinal data from 198 very preterm and 70 full term children, this study characterised the memory and learning abilities of very preterm children at 7 years of age in both verbal and visual domains. The relationship between the extent of brain abnormalities on neonatal magnetic resonance imaging (MRI) and memory and learning outcomes at 7 years of age in very preterm children was also investigated. Neonatal MRI scans were qualitatively assessed for global, white-matter, cortical grey-matter, deep grey-matter, and cerebellar abnormalities. Very preterm children performed less well on measures of immediate memory, working memory, long-term memory, and learning compared with term-born controls. Neonatal brain abnormalities, and in particular deep grey-matter abnormality, were associated with poorer memory and learning performance at 7 years in very preterm children. Findings support the importance of cerebral neonatal pathology for predicting later memory and learning function.

  18. Sensory experience ratings (SERs) for 1,659 French words: Relationships with other psycholinguistic variables and visual word recognition.

    PubMed

    Bonin, Patrick; Méot, Alain; Ferrand, Ludovic; Bugaïska, Aurélia

    2015-09-01

    We collected sensory experience ratings (SERs) for 1,659 French words in adults. Sensory experience for words is a recently introduced variable that corresponds to the degree to which words elicit sensory and perceptual experiences (Juhasz & Yap Behavior Research Methods, 45, 160-168, 2013; Juhasz, Yap, Dicke, Taylor, & Gullick Quarterly Journal of Experimental Psychology, 64, 1683-1691, 2011). The relationships of the sensory experience norms with other psycholinguistic variables (e.g., imageability and age of acquisition) were analyzed. We also investigated the degree to which SER predicted performance in visual word recognition tasks (lexical decision, word naming, and progressive demasking). The analyses indicated that SER reliably predicted response times in lexical decision, but not in word naming or progressive demasking. The findings are discussed in relation to the status of SER, the role of semantic code activation in visual word recognition, and the embodied view of cognition.

  19. Stroke survivors' views and experiences on impact of visual impairment.

    PubMed

    Rowe, Fiona J

    2017-09-01

    We sought to determine stroke survivors' views on impact of stroke-related visual impairment to quality of life. Stroke survivors with visual impairment, more than 1 year post stroke onset, were recruited. Semistructured biographical narrative interviews were audio-recorded and transcribed verbatim. A thematic approach to analysis of the qualitative data was adopted. Transcripts were systematically coded using NVivo10 software. Thirty-five stroke survivors were interviewed across the UK: 16 females, 19 males; aged 20-75 years at stroke onset. Five qualitative themes emerged: "Formal care," "Symptoms and self," "Adaptations," "Daily life," and "Information." Where visual problems existed, they were often not immediately recognized as part of the stroke syndrome and attributed to other causes such as migraine. Many participants did not receive early vision assessment or treatment for their visual problems. Visual problems included visual field loss, double vision, and perceptual problems. Impact of visual problems included loss in confidence, being a burden to others, increased collisions/accidents, and fear of falling. They made many self-identified adaptations to compensate for visual problems: magnifiers, large print, increased lighting, use of white sticks. There was a consistent lack of support and provision of information about visual problems. Poststroke visual impairment causes considerable impact to daily life which could be substantially improved by simple measures including early formal visual assessment, management and advice on adaptive strategies and self-management options. Improved education about poststroke visual impairment for the public and clinicians could aid earlier diagnosis of visual impairments.

  20. Nogo Receptor 1 Confines a Disinhibitory Microcircuit to the Critical Period in Visual Cortex.

    PubMed

    Stephany, Céleste-Élise; Ikrar, Taruna; Nguyen, Collins; Xu, Xiangmin; McGee, Aaron W

    2016-10-26

    A characteristic of the developing mammalian visual system is a brief interval of plasticity, termed the "critical period," when the circuitry of primary visual cortex is most sensitive to perturbation of visual experience. Depriving one eye of vision (monocular deprivation [MD]) during the critical period alters ocular dominance (OD) by shifting the responsiveness of neurons in visual cortex to favor the nondeprived eye. A disinhibitory microcircuit involving parvalbumin-expressing (PV) interneurons initiates this OD plasticity. The gene encoding the neuronal nogo-66-receptor 1 (ngr1/rtn4r) is required to close the critical period. Here we combined mouse genetics, electrophysiology, and circuit mapping with laser-scanning photostimulation to investigate whether disinhibition is confined to the critical period by ngr1 We demonstrate that ngr1 mutant mice retain plasticity characteristic of the critical period as adults, and that ngr1 operates within PV interneurons to restrict the loss of intracortical excitatory synaptic input following MD in adult mice, and this disinhibition induces a "lower PV network configuration" in both critical-period wild-type mice and adult ngr1 -/- mice. We propose that ngr1 limits disinhibition to close the critical period for OD plasticity and that a decrease in PV expression levels reports the diminished recent cumulative activity of these interneurons. Life experience refines brain circuits throughout development during specified critical periods. Abnormal experience during these critical periods can yield enduring maladaptive changes in neural circuits that impair brain function. In the developing visual system, visual deprivation early in life can result in amblyopia (lazy-eye), a prevalent childhood disorder comprising permanent deficits in spatial vision. Here we identify that the nogo-66 receptor 1 gene restricts an early and essential step in OD plasticity to the critical period. These findings link the emerging circuit

  1. Abnormal ventricular development in preterm neonates with visually normal MRIs

    NASA Astrophysics Data System (ADS)

    Shi, Jie; Wang, Yalin; Lao, Yi; Ceschin, Rafael; Mi, Liang; Nelson, Marvin D.; Panigrahy, Ashok; Leporé, Natasha

    2015-12-01

    Children born preterm are at risk for a wide range of neurocognitive and neurobehavioral disorders. Some of these may stem from early brain abnormalities at the neonatal age. Hence, a precise characterization of neonatal neuroanatomy may help inform treatment strategies. In particular, the ventricles are often enlarged in neurocognitive disorders, due to atrophy of surrounding tissues. Here we present a new pipeline for the detection of morphological and relative pose differences in the ventricles of premature neonates compared to controls. To this end, we use a new hyperbolic Ricci flow based mapping of the ventricular surfaces of each subjects to the Poincaré disk. Resulting surfaces are then registered to a template, and a between group comparison is performed using multivariate tensor-based morphometry. We also statistically compare the relative pose of the ventricles within the brain between the two groups, by performing a Procrustes alignment between each subject's ventricles and an average shape. For both types of analyses, differences were found in the left ventricles between the two groups.

  2. Using spectral imaging for the analysis of abnormalities for colorectal cancer: When is it helpful?

    PubMed

    Awan, Ruqayya; Al-Maadeed, Somaya; Al-Saady, Rafif

    2018-01-01

    The spectral imaging technique has been shown to provide more discriminative information than the RGB images and has been proposed for a range of problems. There are many studies demonstrating its potential for the analysis of histopathology images for abnormality detection but there have been discrepancies among previous studies as well. Many multispectral based methods have been proposed for histopathology images but the significance of the use of whole multispectral cube versus a subset of bands or a single band is still arguable. We performed comprehensive analysis using individual bands and different subsets of bands to determine the effectiveness of spectral information for determining the anomaly in colorectal images. Our multispectral colorectal dataset consists of four classes, each represented by infra-red spectrum bands in addition to the visual spectrum bands. We performed our analysis of spectral imaging by stratifying the abnormalities using both spatial and spectral information. For our experiments, we used a combination of texture descriptors with an ensemble classification approach that performed best on our dataset. We applied our method to another dataset and got comparable results with those obtained using the state-of-the-art method and convolutional neural network based method. Moreover, we explored the relationship of the number of bands with the problem complexity and found that higher number of bands is required for a complex task to achieve improved performance. Our results demonstrate a synergy between infra-red and visual spectrum by improving the classification accuracy (by 6%) on incorporating the infra-red representation. We also highlight the importance of how the dataset should be divided into training and testing set for evaluating the histopathology image-based approaches, which has not been considered in previous studies on multispectral histopathology images.

  3. Using spectral imaging for the analysis of abnormalities for colorectal cancer: When is it helpful?

    PubMed Central

    Al-Maadeed, Somaya; Al-Saady, Rafif

    2018-01-01

    The spectral imaging technique has been shown to provide more discriminative information than the RGB images and has been proposed for a range of problems. There are many studies demonstrating its potential for the analysis of histopathology images for abnormality detection but there have been discrepancies among previous studies as well. Many multispectral based methods have been proposed for histopathology images but the significance of the use of whole multispectral cube versus a subset of bands or a single band is still arguable. We performed comprehensive analysis using individual bands and different subsets of bands to determine the effectiveness of spectral information for determining the anomaly in colorectal images. Our multispectral colorectal dataset consists of four classes, each represented by infra-red spectrum bands in addition to the visual spectrum bands. We performed our analysis of spectral imaging by stratifying the abnormalities using both spatial and spectral information. For our experiments, we used a combination of texture descriptors with an ensemble classification approach that performed best on our dataset. We applied our method to another dataset and got comparable results with those obtained using the state-of-the-art method and convolutional neural network based method. Moreover, we explored the relationship of the number of bands with the problem complexity and found that higher number of bands is required for a complex task to achieve improved performance. Our results demonstrate a synergy between infra-red and visual spectrum by improving the classification accuracy (by 6%) on incorporating the infra-red representation. We also highlight the importance of how the dataset should be divided into training and testing set for evaluating the histopathology image-based approaches, which has not been considered in previous studies on multispectral histopathology images. PMID:29874262

  4. Wearable ultrasonic guiding device with white cane for the visually impaired: A preliminary verisimilitude experiment.

    PubMed

    Cheng, Po-Hsun

    2016-01-01

    Several assistive technologies are available to help visually impaired individuals avoid obstructions while walking. Unfortunately, white canes and medical walkers are unable to detect obstacles on the road or react to encumbrances located above the waist. In this study, I adopted the cyber-physical system approach in the development of a cap-connected device to compensate for gaps in detection associated with conventional aids for the visually impaired. I developed a verisimilar, experimental route involving the participation of seven individuals with visual impairment, including straight sections, left turns, right turns, curves, and suspended objects. My aim was to facilitate the collection of information required for the practical use of the device. My findings demonstrate the feasibility of the proposed guiding device in alerting walkers to the presence of some kinds of obstacles from the small number of subjects. That is, it shows promise for future work and research with the proposed device. My findings provide a valuable reference for the further improvement of these devices as well as the establishment of experiments involving the visually impaired.

  5. Allocentric but not egocentric visual memory difficulties in adults with ADHD may represent cognitive inefficiency.

    PubMed

    Brown, Franklin C; Roth, Robert M; Katz, Lynda J

    2015-08-30

    Attention Deficit Hyperactivity Disorder (ADHD) has often been conceptualized as arising executive dysfunctions (e.g., inattention, defective inhibition). However, recent studies suggested that cognitive inefficiency may underlie many ADHD symptoms, according to reaction time and processing speed abnormalities. This study explored whether a non-timed measure of cognitive inefficiency would also be abnormal. A sample of 23 ADHD subjects was compared to 23 controls on a test that included both egocentric and allocentric visual memory subtests. A factor analysis was used to determine which cognitive variables contributed to allocentric visual memory. The ADHD sample performed significantly lower on the allocentric but not egocentric conditions. Allocentric visual memory was not associated with timed, working memory, visual perception, or mental rotation variables. This paper concluded by discussing how these results supported a cognitive inefficiency explanation for some ADHD symptoms, and discussed future research directions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Healthcare experiences of women with visual impairment.

    PubMed

    Sharts-Hopko, Nancy C; Smeltzer, Suzanne; Ott, Barbara B; Zimmerman, Vanessa; Duffin, Janice

    2010-01-01

    This investigation was a secondary analysis of focus group transcripts to address the question of how women with low vision or blindness have experienced healthcare. Secondary analysis of qualitative data was performed on transcripts from 2 focus groups. These focus groups were conducted at an agency serving visually impaired people in Philadelphia. The 2 focus groups included 7 and 11 women, respectively, having low-vision or who are blind who had been part of an original study of reaching hard-to-reach women with disabilities. Content analysis for the identification of thematic clusters was performed on transcriptions of the focus group data. Findings are consistent with existing research on the health needs of women with disabilities but add specific understanding related to visual impairment. Six thematic categories were identified: health professionals' awareness, information access, healthcare access, isolation, the need for self-advocacy, and perception by others. Secondary analysis of qualitative data affords in-depth understanding of a particular subset of participants within a larger study. Clinical nurse specialists and other health professionals need to increase their sensitivity to the challenges faced by women with visual impairment, and plan and provide care accordingly. Health professions students need to be prepared to interact with people who are visually impaired and healthcare settings need to respond to their needs.

  7. Independent sources of anisotropy in visual orientation representation: a visual and a cognitive oblique effect.

    PubMed

    Balikou, Panagiota; Gourtzelidis, Pavlos; Mantas, Asimakis; Moutoussis, Konstantinos; Evdokimidis, Ioannis; Smyrnis, Nikolaos

    2015-11-01

    The representation of visual orientation is more accurate for cardinal orientations compared to oblique, and this anisotropy has been hypothesized to reflect a low-level visual process (visual, "class 1" oblique effect). The reproduction of directional and orientation information also leads to a mean error away from cardinal orientations or directions. This anisotropy has been hypothesized to reflect a high-level cognitive process of space categorization (cognitive, "class 2," oblique effect). This space categorization process would be more prominent when the visual representation of orientation degrades such as in the case of working memory with increasing cognitive load, leading to increasing magnitude of the "class 2" oblique effect, while the "class 1" oblique effect would remain unchanged. Two experiments were performed in which an array of orientation stimuli (1-4 items) was presented and then subjects had to realign a probe stimulus within the previously presented array. In the first experiment, the delay between stimulus presentation and probe varied, while in the second experiment, the stimulus presentation time varied. The variable error was larger for oblique compared to cardinal orientations in both experiments reproducing the visual "class 1" oblique effect. The mean error also reproduced the tendency away from cardinal and toward the oblique orientations in both experiments (cognitive "class 2" oblique effect). The accuracy or the reproduced orientation degraded (increasing variable error) and the cognitive "class 2" oblique effect increased with increasing memory load (number of items) in both experiments and presentation time in the second experiment. In contrast, the visual "class 1" oblique effect was not significantly modulated by any one of these experimental factors. These results confirmed the theoretical predictions for the two anisotropies in visual orientation reproduction and provided support for models proposing the categorization of

  8. Meiotic abnormalities

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1993-12-31

    Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

  9. Visual imagery without visual perception: lessons from blind subjects

    NASA Astrophysics Data System (ADS)

    Bértolo, Helder

    2014-08-01

    The question regarding visual imagery and visual perception remain an open issue. Many studies have tried to understand if the two processes share the same mechanisms or if they are independent, using different neural substrates. Most research has been directed towards the need of activation of primary visual areas during imagery. Here we review some of the works providing evidence for both claims. It seems that studying visual imagery in blind subjects can be used as a way of answering some of those questions, namely if it is possible to have visual imagery without visual perception. We present results from the work of our group using visual activation in dreams and its relation with EEG's spectral components, showing that congenitally blind have visual contents in their dreams and are able to draw them; furthermore their Visual Activation Index is negatively correlated with EEG alpha power. This study supports the hypothesis that it is possible to have visual imagery without visual experience.

  10. Abnormal grain growth in iron-silicon

    NASA Astrophysics Data System (ADS)

    Bennett, Tricia A.

    Abnormal grain growth (AGG) was studied in an Fe-1%Si alloy using automated Electron Backscattered Diffraction (EBSD) to determine the driving force for this phenomenon. Experiments were performed with the knowledge that there are several possible driving forces and, the intent to determine the true driving force by elimination of the other potential candidates. These potential candidates include surface energy anisotropy, anisotropic grain boundary properties and the stored energy of deformation. In this work, surface energy and grain boundary anisotropies as well as the stored energy of deformation were investigated as the possible driving forces for AGG. Accordingly, industrially processed samples that were temper rolled to 1.5% and 8% were annealed in air for various times followed by quenching in water. The results obtained were compared to those from heat treatments performed in wet 15%H2-85%N2 at a US Steel facility. In addition, for a more complete study of the effect of surface energy anisotropies on AGG, the 1.5% temper-rolled material was heat-treated in other atmospheres such as 5%H2-95%Ar, 98%H2-2%He, 98%H2-2%H 2S, and 98%H2-2%N2 for 1 hour followed by quenching in water. The character of the grain boundaries in the materials was also examined for each set of experiments conducted, while the influence of stored energy was evaluated by examining intragranular orientation gradients. AGG occurred regardless of annealing atmosphere though the most rapid progression was observed in samples annealed in air. In general, grains of varying orientations grew abnormally. One consistently observed trend in all the detailed studies was that the matrix grains remained essentially static and either did not grow or only grew very slowly. On the other hand, the abnormally large grains (ALG), on average, were approximately 10 times the size of the matrix. Analysis of the grain boundary character of the interfaces between abnormal grains and the matrix showed no

  11. Ego depletion in visual perception: Ego-depleted viewers experience less ambiguous figure reversal.

    PubMed

    Wimmer, Marina C; Stirk, Steven; Hancock, Peter J B

    2017-10-01

    This study examined the effects of ego depletion on ambiguous figure perception. Adults (N = 315) received an ego depletion task and were subsequently tested on their inhibitory control abilities that were indexed by the Stroop task (Experiment 1) and their ability to perceive both interpretations of ambiguous figures that was indexed by reversal (Experiment 2). Ego depletion had a very small effect on reducing inhibitory control (Cohen's d = .15) (Experiment 1). Ego-depleted participants had a tendency to take longer to respond in Stroop trials. In Experiment 2, ego depletion had small to medium effects on the experience of reversal. Ego-depleted viewers tended to take longer to reverse ambiguous figures (duration to first reversal) when naïve of the ambiguity and experienced less reversal both when naïve and informed of the ambiguity. Together, findings suggest that ego depletion has small effects on inhibitory control and small to medium effects on bottom-up and top-down perceptual processes. The depletion of cognitive resources can reduce our visual perceptual experience.

  12. Visual recognition and visually guided action after early bilateral lesion of occipital cortex: a behavioral study of a 4.6-year-old girl.

    PubMed

    Amicuzi, Ileana; Stortini, Massimo; Petrarca, Maurizio; Di Giulio, Paola; Di Rosa, Giuseppe; Fariello, Giuseppe; Longo, Daniela; Cannatà, Vittorio; Genovese, Elisabetta; Castelli, Enrico

    2006-10-01

    We report the case of a 4.6-year-old girl born pre-term with early bilateral occipital damage. It was revealed that the child had non-severely impaired basic visual abilities and ocular motility, a selective perceptual deficit of figure-ground segregation, impaired visual recognition and abnormal navigating through space. Even if the child's visual functioning was not optimal, this was the expression of adaptive anatomic and functional brain modifications that occurred following the early lesion. Anatomic brain structure was studied with anatomic MRI and Diffusor Tensor Imaging (DTI)-MRI. This behavioral study may provide an important contribution to understanding the impact of an early lesion of the visual system on the development of visual functions and on the immature brain's potential for reorganisation related to when the damage occurred.

  13. Aesthetic perception of visual textures: a holistic exploration using texture analysis, psychological experiment, and perception modeling.

    PubMed

    Liu, Jianli; Lughofer, Edwin; Zeng, Xianyi

    2015-01-01

    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 non-linear 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.

  14. Experiences in using DISCUS for visualizing human communication

    NASA Astrophysics Data System (ADS)

    Groehn, Matti; Nieminen, Marko; Haho, Paeivi; Smeds, Riitta

    2000-02-01

    In this paper, we present further improvement to the DISCUS software that can be used to record and analyze the flow and constants of business process simulation session discussion. The tool was initially introduced in 'visual data exploration and analysis IV' conference. The initial features of the tool enabled the visualization of discussion flow in business process simulation sessions and the creation of SOM analyses. The improvements of the tool consists of additional visualization possibilities that enable quick on-line analyses and improved graphical statistics. We have also created the very first interface to audio data and implemented two ways to visualize it. We also outline additional possibilities to use the tool in other application areas: these include usability testing and the possibility to use the tool for capturing design rationale in a product development process. The data gathered with DISCUS may be used in other applications, and further work may be done with data ming techniques.

  15. Hiding and finding: the relationship between visual concealment and visual search.

    PubMed

    Smilek, Daniel; Weinheimer, Laura; Kwan, Donna; Reynolds, Mike; Kingstone, Alan

    2009-11-01

    As an initial step toward developing a theory of visual concealment, we assessed whether people would use factors known to influence visual search difficulty when the degree of concealment of objects among distractors was varied. In Experiment 1, participants arranged search objects (shapes, emotional faces, and graphemes) to create displays in which the targets were in plain sight but were either easy or hard to find. Analyses of easy and hard displays created during Experiment 1 revealed that the participants reliably used factors known to influence search difficulty (e.g., eccentricity, target-distractor similarity, presence/absence of a feature) to vary the difficulty of search across displays. In Experiment 2, a new participant group searched for the targets in the displays created by the participants in Experiment 1. Results indicated that search was more difficult in the hard than in the easy condition. In Experiments 3 and 4, participants used presence versus absence of a feature to vary search difficulty with several novel stimulus sets. Taken together, the results reveal a close link between the factors that govern concealment and the factors known to influence search difficulty, suggesting that a visual search theory can be extended to form the basis of a theory of visual concealment.

  16. Do you see what I see? The difference between dog and human visual perception may affect the outcome of experiments.

    PubMed

    Pongrácz, Péter; Ujvári, Vera; Faragó, Tamás; Miklósi, Ádám; Péter, András

    2017-07-01

    The visual sense of dogs is in many aspects different than that of humans. Unfortunately, authors do not explicitly take into consideration dog-human differences in visual perception when designing their experiments. With an image manipulation program we altered stationary images, according to the present knowledge about dog-vision. Besides the effect of dogs' dichromatic vision, the software shows the effect of the lower visual acuity and brightness discrimination, too. Fifty adult humans were tested with pictures showing a female experimenter pointing, gazing or glancing to the left or right side. Half of the pictures were shown after they were altered to a setting that approximated dog vision. Participants had difficulty to find out the direction of glancing when the pictures were in dog-vision mode. Glances in dog-vision setting were followed less correctly and with a slower response time than other cues. Our results are the first that show the visual performance of humans under circumstances that model how dogs' weaker vision would affect their responses in an ethological experiment. We urge researchers to take into consideration the differences between perceptual abilities of dogs and humans, by developing visual stimuli that fit more appropriately to dogs' visual capabilities. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. H3 and H4 Lysine Acetylation Correlates with Developmental and Experimentally Induced Adult Experience-Dependent Plasticity in the Mouse Visual Cortex

    PubMed Central

    Vierci, Gabriela; Pannunzio, Bruno; Bornia, Natalia; Rossi, Francesco M.

    2016-01-01

    Histone posttranslational modifications play a fundamental role in orchestrating gene expression. In this work, we analyzed the acetylation of H3 and H4 histones (AcH3–AcH4) and its modulation by visual experience in the mouse visual cortex (VC) during normal development and in two experimental conditions that restore juvenile-like plasticity levels in adults (fluoxetine treatment and enriched environment). We found that AcH3–AcH4 declines with age and is upregulated by treatments restoring plasticity in the adult. We also found that visual experience modulates AcH3–AcH4 in young and adult plasticity-restored mice but not in untreated ones. Finally, we showed that the transporter vGAT is downregulated in adult plasticity-restored models. In summary, we identified a dynamic regulation of AcH3–AcH4, which is associated with high plasticity levels and enhanced by visual experience. These data, along with recent ones, indicate H3–H4 acetylation as a central hub in the control of experience-dependent plasticity in the VC. PMID:27891053

  18. The impact of facial abnormalities and their spatial position on perception of cuteness and attractiveness of infant faces

    PubMed Central

    Lewis, Jennifer; Roberson, Debi

    2017-01-01

    Research has demonstrated that how “cute” an infant is perceived to be has consequences for caregiving. Infants with facial abnormalities receive lower ratings of cuteness, but relatively little is known about how different abnormalities and their location affect these aesthetic judgements. The objective of the current study was to compare the impact of different abnormalities on the perception of infant faces, while controlling for infant identity. In two experiments, adult participants gave ratings of cuteness and attractiveness in response to face images that had been edited to introduce common facial abnormalities. Stimulus faces displayed either a haemangioma (a small, benign birth mark), strabismus (an abnormal alignment of the eyes) or a cleft lip (an abnormal opening in the upper lip). In Experiment 1, haemangioma had less of a detrimental effect on ratings than the more severe abnormalities. In Experiment 2, we manipulated the position of a haemangioma on the face. We found small but robust effects of this position, with abnormalities in the top and on the left of the face receiving lower cuteness ratings. This is consistent with previous research showing that people attend more to the top of the face (particularly the eyes) and to the left hemifield. PMID:28749958

  19. Single-Cell Analysis of Experience-Dependent Transcriptomic States in Mouse Visual Cortex

    PubMed Central

    Hrvatin, Sinisa; Hochbaum, Daniel R.; Nagy, M. Aurel; Cicconet, Marcelo; Robertson, Keiramarie; Cheadle, Lucas; Zilionis, Rapolas; Ratner, Alex; Borges-Monroy, Rebeca; Klein, Allon M.; Sabatini, Bernardo L.; Greenberg, Michael E.

    2017-01-01

    Activity-dependent transcriptional responses shape cortical function. However, we lack a comprehensive understanding of the diversity of these responses across the full range of cortical cell types, and how these changes contribute to neuronal plasticity and disease. Here we applied high-throughput single-cell RNA-sequencing to investigate the breadth of transcriptional changes that occur across cell types in mouse visual cortex following exposure to light. We identified significant and divergent transcriptional responses to stimulation in each of the 30 cell types characterized, revealing 611 stimulus-responsive genes. Excitatory pyramidal neurons exhibit inter- and intra-laminar heterogeneity in the induction of stimulus responsive genes. Non-neuronal cells demonstrated clear transcriptional responses that may regulate experience-dependent changes in neurovascular coupling and myelination. Together, these results reveal the dynamic landscape of stimulus-dependent transcriptional changes that occur across cell types in visual cortex, which are likely critical for cortical function and may be sites of de-regulation in developmental brain disorders. PMID:29230054

  20. Abnormal branching and regression of the notochord and its relationship to foregut abnormalities.

    PubMed

    Vleesch Dubois, V N; Quan Qi, B; Beasley, S W; Williams, A

    2002-04-01

    An abnormally positioned notochord has been reported in embryos that develop foregut abnormalities, vertebral defects and other abnormalities of the VATER association. This study examines the patterns of regression of the abnormal notochord in the rat model of the VATER association and investigates the relationship between developmental abnormalities of the notochord and those of the vertebra and foregut. Timed-pregnant Sprague-Dawley rats were given daily intraperitoneal injections of 1.75 mg/kg adriamycin on gestational days 6 - 9 inclusive. Rats were sacrificed between days 14 and 20 and their embryos harvested, histologically sectioned and stained and examined serially. The location and appearance of the degenerating notochord and its relationship to regional structural defects were analysed. All 26 embryos exposed to adriamycin developed foregut abnormalities and had an abnormal notochord. The notochord disappeared by a process of apoptotic degeneration that lagged behind that of the normal embryo: the notochord persisted in the abnormal embryo beyond day 17, whereas in the normal rat it had already disappeared. Similarly, formation of the nucleus pulposus was delayed. Vertebral abnormalities occurred when the notochord was ventrally-positioned. The notochord disappears during day 16 in the normal embryo whereas abnormal branches of the notochord persist until day 19 in the adriamycin-treated embryo. Degeneration of the notochord is dominated by apoptosis. An excessively ventrally-placed notochord is closely associated with abnormalities of the vertebral column, especially hemivertebrae.

  1. Causes and anatomical site of blindness and severe visual loss in Isfahan, Islamic Republic of Iran.

    PubMed

    Dehghan, A; Kianersi, F; Moazam, E; Ghanbari, H

    2010-02-01

    This study in 2005 evaluated the causes and major anatomical site of blindness and severe visual loss at a school for blind children in Isfahan province, Islamic Republic of Iran. All 211 students were examined according to the modified WHO/PBL eye examination record: 70.4% were blind, 24.3% had severe visual loss and 5.3% were visually impaired. The major causes of abnormality were hereditary factors (42.7%), prenatal/neonatal (18.5%) and unknown etiology (35.5%). The main sites of abnormality were the retina (62.6%), whole globe (17.5%), lens (7.1%) and optic nerve (7.1%). A high proportion of parents were in a consanguineous marriage (49.2%). The pattern of blindness in Isfahan encompasses characteristics of both developed and developing countries.

  2. pySeismicDQA: open source post experiment data quality assessment and processing

    NASA Astrophysics Data System (ADS)

    Polkowski, Marcin

    2017-04-01

    Seismic Data Quality Assessment is python based, open source set of tools dedicated for data processing after passive seismic experiments. Primary goal of this toolset is unification of data types and formats from different dataloggers necessary for further processing. This process requires additional data checks for errors, equipment malfunction, data format errors, abnormal noise levels, etc. In all such cases user needs to decide (manually or by automatic threshold) if data is removed from output dataset. Additionally, output dataset can be visualized in form of website with data availability charts and waveform visualization with earthquake catalog (external). Data processing can be extended with simple STA/LTA event detection. pySeismicDQA is designed and tested for two passive seismic experiments in central Europe: PASSEQ 2006-2008 and "13 BB Star" (2013-2016). National Science Centre Poland provided financial support for this work via NCN grant DEC-2011/02/A/ST10/00284.

  3. Improving visual observation skills through the arts to aid radiographic interpretation in veterinary practice: A pilot study.

    PubMed

    Beck, Cathy; Gaunt, Heather; Chiavaroli, Neville

    2017-09-01

    Radiographic interpretation is a perceptual and cognitive skill. Recently core veterinary radiology textbooks have focused on the cognitive (i.e., the clinical aspects of radiographic interpretation) rather than the features of visual observation that improve identification of abnormalities. As a result, the skill of visual observation is underemphasized and thus often underdeveloped by trainees. The study of the arts in medical education has been used to train and improve visual observation and empathy. The use of the arts to improve visual observation skills in Veterinary Science has not been previously described. Objectives of this pilot study were to adapt the existing Visual Arts in Health Education Program for medical and dental students at the University of Melbourne, Australia to third year Doctor of Veterinary Medicine students and evaluate their perceptions regarding the program's effects on visual observation skills and confidence with respect to radiographic interpretation. This adaptation took the form of a single seminar given to third year Doctor of Veterinary Medicine students. Following the seminar, students reported an improved approach to radiographic interpretation and felt they had gained skills which would assist them throughout their career. In the year following the seminar, written reports of the students who attended the seminar were compared with reports from a matched cohort of students who did not attend the seminar. This demonstrated increased identification of abnormalities and greater description of the abnormalities identified. Findings indicated that explicit training in visual observation may be a valuable adjunct to the radiology training of Doctor of Veterinary Medicine students. © 2017 American College of Veterinary Radiology.

  4. Role of Visual Feedback Treatment for Defective /s/ Sounds in Patients with Cleft Palate.

    ERIC Educational Resources Information Center

    Michi, Ken-ichi; And Others

    1993-01-01

    Six patients with cleft palate were provided treatment using either visual feedback for tongue placement and frication or no visual feedback. Results indicated the feedback was especially useful in the treatment of defective /s/ sounds in the patients who exhibited abnormal posterior tongue posturing during dental or alveolar sounds. (Author/DB)

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

    PubMed Central

    Alm, Magnus; Behne, Dawn

    2015-01-01

    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 toward more visually dominated responses. PMID:26236274

  6. Abnormal Sleep/Wake Dynamics in Orexin Knockout Mice

    PubMed Central

    Diniz Behn, Cecilia G.; Klerman, Elizabeth B.; Mochizuki, Takatoshi; Lin, Shih-Chieh; Scammell, Thomas E.

    2010-01-01

    Study Objectives: Narcolepsy with cataplexy is caused by a loss of orexin (hypocretin) signaling, but the physiologic mechanisms that result in poor maintenance of wakefulness and fragmented sleep remain unknown. Conventional scoring of sleep cannot reveal much about the process of transitioning between states or the variations within states. We developed an EEG spectral analysis technique to determine whether the state instability in a mouse model of narcolepsy reflects abnormal sleep or wake states, faster movements between states, or abnormal transitions between states. Design: We analyzed sleep recordings in orexin knockout (OXKO) mice and wild type (WT) littermates using a state space analysis technique. This non-categorical approach allows quantitative and unbiased examination of sleep/wake states and state transitions. Measurements and Results: OXKO mice spent less time in deep, delta-rich NREM sleep and in active, theta-rich wake and instead spent more time near the transition zones between states. In addition, while in the midst of what should be stable wake, OXKO mice initiated rapid changes into NREM sleep with high velocities normally seen only in transition regions. Consequently, state transitions were much more frequent and rapid even though the EEG progressions during state transitions were normal. Conclusions: State space analysis enables visualization of the boundaries between sleep and wake and shows that narcoleptic mice have less distinct and more labile states of sleep and wakefulness. These observations provide new perspectives on the abnormal state dynamics resulting from disrupted orexin signaling and highlight the usefulness of state space analysis in understanding narcolepsy and other sleep disorders. Citation: Diniz Behn CG; Klerman EB; Mochizuki T; Lin S; Scammell TE. Abnormal sleep/wake dynamics in orexin knockout mice. SLEEP 2010;33(3):297-306. PMID:20337187

  7. Experimenting with Visual Storytelling in Students' Portfolios: Narratives of Visual Pedagogy for Pre-Service Teacher Education

    ERIC Educational Resources Information Center

    Rifa-Valls, Montserrat

    2011-01-01

    This article interprets the repercussions of visual storytelling for art education and arts-based narrative research and, particularly, it approaches visual storytelling as a critical tool for pre-service teacher education. After reinterpreting storytelling from the perspective of visual critical pedagogy, I will narratively reconstruct the use of…

  8. Brain abnormality segmentation based on l1-norm minimization

    NASA Astrophysics Data System (ADS)

    Zeng, Ke; Erus, Guray; Tanwar, Manoj; Davatzikos, Christos

    2014-03-01

    We present a method that uses sparse representations to model the inter-individual variability of healthy anatomy from a limited number of normal medical images. Abnormalities in MR images are then defined as deviations from the normal variation. More precisely, we model an abnormal (pathological) signal y as the superposition of a normal part ~y that can be sparsely represented under an example-based dictionary, and an abnormal part r. Motivated by a dense error correction scheme recently proposed for sparse signal recovery, we use l1- norm minimization to separate ~y and r. We extend the existing framework, which was mainly used on robust face recognition in a discriminative setting, to address challenges of brain image analysis, particularly the high dimensionality and low sample size problem. The dictionary is constructed from local image patches extracted from training images aligned using smooth transformations, together with minor perturbations of those patches. A multi-scale sliding-window scheme is applied to capture anatomical variations ranging from fine and localized to coarser and more global. The statistical significance of the abnormality term r is obtained by comparison to its empirical distribution through cross-validation, and is used to assign an abnormality score to each voxel. In our validation experiments the method is applied for segmenting abnormalities on 2-D slices of FLAIR images, and we obtain segmentation results consistent with the expert-defined masks.

  9. The case of the missing visual details: Occlusion and long-term visual memory.

    PubMed

    Williams, Carrick C; Burkle, Kyle A

    2017-10-01

    To investigate the critical information in long-term visual memory representations of objects, we used occlusion to emphasize 1 type of information or another. By occluding 1 solid side of the object (e.g., top 50%) or by occluding 50% of the object with stripes (like a picket fence), we emphasized visible information about the object, processing the visible details in the former and the object's overall form in the latter. On a token discrimination test, surprisingly, memory for solid or stripe occluded objects at either encoding (Experiment 1) or test (Experiment 2) was the same. In contrast, when occluded objects matched at encoding and test (Experiment 3) or when the occlusion shifted, revealing the entire object piecemeal (Experiment 4), memory was better for solid compared with stripe occluded objects, indicating that objects are represented differently in long-term visual memory. Critically, we also found that when the task emphasized remembering exactly what was shown, memory performance in the more detailed solid occlusion condition exceeded that in the stripe condition (Experiment 5). However, when the task emphasized the whole object form, memory was better in the stripe condition (Experiment 6) than in the solid condition. We argue that long-term visual memory can represent objects flexibly, and task demands can interact with visual information, allowing the viewer to cope with changing real-world visual environments. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  10. Visual feature extraction and establishment of visual tags in the intelligent visual internet of things

    NASA Astrophysics Data System (ADS)

    Zhao, Yiqun; Wang, Zhihui

    2015-12-01

    The Internet of things (IOT) is a kind of intelligent networks which can be used to locate, track, identify and supervise people and objects. One of important core technologies of intelligent visual internet of things ( IVIOT) is the intelligent visual tag system. In this paper, a research is done into visual feature extraction and establishment of visual tags of the human face based on ORL face database. Firstly, we use the principal component analysis (PCA) algorithm for face feature extraction, then adopt the support vector machine (SVM) for classifying and face recognition, finally establish a visual tag for face which is already classified. We conducted a experiment focused on a group of people face images, the result show that the proposed algorithm have good performance, and can show the visual tag of objects conveniently.

  11. How visual working memory contents influence priming of visual attention.

    PubMed

    Carlisle, Nancy B; Kristjánsson, Árni

    2017-04-12

    Recent evidence shows that when the contents of visual working memory overlap with targets and distractors in a pop-out search task, intertrial priming is inhibited (Kristjánsson, Sævarsson & Driver, Psychon Bull Rev 20(3):514-521, 2013, Experiment 2, Psychonomic Bulletin and Review). This may reflect an interesting interaction between implicit short-term memory-thought to underlie intertrial priming-and explicit visual working memory. Evidence from a non-pop-out search task suggests that it may specifically be holding distractors in visual working memory that disrupts intertrial priming (Cunningham & Egeth, Psychol Sci 27(4):476-485, 2016, Experiment 2, Psychological Science). We examined whether the inhibition of priming depends on whether feature values in visual working memory overlap with targets or distractors in the pop-out search, and we found that the inhibition of priming resulted from holding distractors in visual working memory. These results are consistent with separate mechanisms of target and distractor effects in intertrial priming, and support the notion that the impact of implicit short-term memory and explicit visual working memory can interact when each provides conflicting attentional signals.

  12. Measuring Software Timing Errors in the Presentation of Visual Stimuli in Cognitive Neuroscience Experiments

    PubMed Central

    Garaizar, Pablo; Vadillo, Miguel A.; López-de-Ipiña, Diego; Matute, Helena

    2014-01-01

    Because of the features provided by an abundance of specialized experimental software packages, personal computers have become prominent and powerful tools in cognitive research. Most of these programs have mechanisms to control the precision and accuracy with which visual stimuli are presented as well as the response times. However, external factors, often related to the technology used to display the visual information, can have a noticeable impact on the actual performance and may be easily overlooked by researchers. The aim of this study is to measure the precision and accuracy of the timing mechanisms of some of the most popular software packages used in a typical laboratory scenario in order to assess whether presentation times configured by researchers do not differ from measured times more than what is expected due to the hardware limitations. Despite the apparent precision and accuracy of the results, important issues related to timing setups in the presentation of visual stimuli were found, and they should be taken into account by researchers in their experiments. PMID:24409318

  13. The accuracy of ultrasound in the diagnosis of congenital abnormalities.

    PubMed

    Munim, Shama; Nadeem, Salva; Khuwaja, Nadya Ali

    2006-01-01

    To determine the accuracy of ultrasound in the diagnosis of congenital abnormalities at the Aga Khan University Hospital, Karachi. The data of congenital abnormalities was obtained from the obstetrical database and medical records of all cases complicated by congenital abnormalities, delivering from January 2001 to December 2003 and was reviewed. Antenatal ultrasounds had been performed by operators with different level of experience. In addition this data was retrieved from the termination and Congenital anomaly register. A structured data collection form was used to collect information of different variables of interest. Congenital abnormalities, complicated 2.8% (n=170), of all deliveries, including all cases of termination of pregnancy, stillbirth and live births. Out of the total, 11.6% occurred in women above the age of 35 years. Consanguinity was found in 18.2% cases. Prenatal diagnosis was made in just under half of the cases (48.8%). Central nervous system and renal abnormalities were commonly diagnosed. However, facial defects, heart defects or skeletal defects were more commonly missed. Antenatal ultrasound successfully diagnosed foetal abnormalities in 48.8% of cases, and more than 90% Central Nervous system defects and renal abnormalities. In contrast about a quarter of Cardiac defects and none of the facial defects were detected. Based on these findings we recommend that the Sonologist should incorporate four chamber view of the heart and also look at the face carefully.

  14. Prenatal diagnosis of sex chromosome abnormalities: the 8-year experience of a single medical center.

    PubMed

    Vaknin, Zvi; Reish, Orit; Ben-Ami, Ido; Heyman, Eli; Herman, Arie; Maymon, Ron

    2008-01-01

    To assess the indications for prenatal karyotyping of sex chromosomal abnormalities (SCAs) during pregnancy. All singleton pregnancies interrupted in our institute because of SCAs (1998-2005) were categorized into subgroups of 45,XO (Turner syndrome), 47,XXY (Klinefelter syndrome), 47,XXX and 47,XYY. The indications for prenatal diagnostic testing were recorded. There were 67 SCAs pregnancies: 33% Turner syndrome, 28% Klinefelter syndrome, 21% 47,XXX and 18% 47,XYY. Maternal age was similar among the 4 groups (34 +/- 5, range 25-42 years). The main indications for fetal karyotyping were abnormal Down's syndrome (DS) screening or ultrasound findings, advanced maternal age (> or =35 years), and parental request. About 2/3 of the Turner and 47,XYY cases had either abnormal DS screening tests or sonographic findings, such as: increased nuchal translucency, mainly cystic hygroma and fetal hydrops. However, fetal karyotyping in more than 2/3 of the 47,XXX and 47,XXY cases was mainly performed because of advanced maternal age, and the diagnosis of fetal SCAs was coincidental (p <0.03). Our recent suggestion to expand the DS screening capacity to other chromosomal abnormalities including SCAs is further supported. Prenatal detection seems to be promising for Turner syndrome and possibly for 47,XYY syndrome, while other SCAs are less likely to be detected either by ultrasound or biochemical screening. (c) 2007 S. Karger AG, Basel

  15. Cocaine Self-Administration Experience Induces Pathological Phasic Accumbens Dopamine Signals and Abnormal Incentive Behaviors in Drug-Abstinent Rats.

    PubMed

    Saddoris, Michael P; Wang, Xuefei; Sugam, Jonathan A; Carelli, Regina M

    2016-01-06

    Chronic exposure to drugs of abuse is linked to long-lasting alterations in the function of limbic system structures, including the nucleus accumbens (NAc). Although cocaine acts via dopaminergic mechanisms within the NAc, less is known about whether phasic dopamine (DA) signaling in the NAc is altered in animals with cocaine self-administration experience or if these animals learn and interact normally with stimuli in their environment. Here, separate groups of rats self-administered either intravenous cocaine or water to a receptacle (controls), followed by 30 d of enforced abstinence. Next, all rats learned an appetitive Pavlovian discrimination and voltammetric recordings of real-time DA release were taken in either the NAc core or shell of cocaine and control subjects. Cocaine experience differentially impaired DA signaling in the core and shell relative to controls. Although phasic DA signals in the shell were essentially abolished for all stimuli, in the core, DA did not distinguish between cues and was abnormally biased toward reward delivery. Further, cocaine rats were unable to learn higher-order associations and even altered simple conditioned approach behaviors, displaying enhanced preoccupation with cue-associated stimuli (sign-tracking; ST) but diminished time at the food cup awaiting reward delivery (goal-tracking). Critically, whereas control DA signaling correlated with ST behaviors, cocaine experience abolished this relationship. These findings show that cocaine has persistent, differential, and pathological effects on both DA signaling and DA-dependent behaviors and suggest that psychostimulant experience may remodel the very circuits that bias organisms toward repeated relapse. Relapsing to drug abuse despite periods of abstinence and sincere attempts to quit is one of the most pernicious facets of addiction. Unfortunately, little is known about how the dopamine (DA) system functions after periods of drug abstinence, particularly its role in

  16. Cocaine Self-Administration Experience Induces Pathological Phasic Accumbens Dopamine Signals and Abnormal Incentive Behaviors in Drug-Abstinent Rats

    PubMed Central

    Wang, Xuefei; Sugam, Jonathan A.; Carelli, Regina M.

    2016-01-01

    Chronic exposure to drugs of abuse is linked to long-lasting alterations in the function of limbic system structures, including the nucleus accumbens (NAc). Although cocaine acts via dopaminergic mechanisms within the NAc, less is known about whether phasic dopamine (DA) signaling in the NAc is altered in animals with cocaine self-administration experience or if these animals learn and interact normally with stimuli in their environment. Here, separate groups of rats self-administered either intravenous cocaine or water to a receptacle (controls), followed by 30 d of enforced abstinence. Next, all rats learned an appetitive Pavlovian discrimination and voltammetric recordings of real-time DA release were taken in either the NAc core or shell of cocaine and control subjects. Cocaine experience differentially impaired DA signaling in the core and shell relative to controls. Although phasic DA signals in the shell were essentially abolished for all stimuli, in the core, DA did not distinguish between cues and was abnormally biased toward reward delivery. Further, cocaine rats were unable to learn higher-order associations and even altered simple conditioned approach behaviors, displaying enhanced preoccupation with cue-associated stimuli (sign-tracking; ST) but diminished time at the food cup awaiting reward delivery (goal-tracking). Critically, whereas control DA signaling correlated with ST behaviors, cocaine experience abolished this relationship. These findings show that cocaine has persistent, differential, and pathological effects on both DA signaling and DA-dependent behaviors and suggest that psychostimulant experience may remodel the very circuits that bias organisms toward repeated relapse. SIGNIFICANCE STATEMENT Relapsing to drug abuse despite periods of abstinence and sincere attempts to quit is one of the most pernicious facets of addiction. Unfortunately, little is known about how the dopamine (DA) system functions after periods of drug abstinence

  17. Visual mental image generation does not overlap with visual short-term memory: a dual-task interference study.

    PubMed

    Borst, Gregoire; Niven, Elaine; Logie, Robert H

    2012-04-01

    Visual mental imagery and working memory are often assumed to play similar roles in high-order functions, but little is known of their functional relationship. In this study, we investigated whether similar cognitive processes are involved in the generation of visual mental images, in short-term retention of those mental images, and in short-term retention of visual information. Participants encoded and recalled visually or aurally presented sequences of letters under two interference conditions: spatial tapping or irrelevant visual input (IVI). In Experiment 1, spatial tapping selectively interfered with the retention of sequences of letters when participants generated visual mental images from aural presentation of the letter names and when the letters were presented visually. In Experiment 2, encoding of the sequences was disrupted by both interference tasks. However, in Experiment 3, IVI interfered with the generation of the mental images, but not with their retention, whereas spatial tapping was more disruptive during retention than during encoding. Results suggest that the temporary retention of visual mental images and of visual information may be supported by the same visual short-term memory store but that this store is not involved in image generation.

  18. Prevalence of macular abnormalities assessed by optical coherence tomography in patients with Usher syndrome.

    PubMed

    Testa, Francesco; Melillo, Paolo; Rossi, Settimio; Marcelli, Vincenzo; de Benedictis, Antonella; Colucci, Raffaella; Gallo, Beatrice; Brunetti-Pierri, Raffaella; Donati, Simone; Azzolini, Claudio; Marciano, Elio; Simonelli, Francesca

    2018-01-01

    To investigate the prevalence of macular abnormalities in patients affected by Usher syndrome (USH), by comparing the clinical findings between two types (i.e., USH1 and USH2). A retrospective study was performed by reviewing optical coherence tomography (OCT) in 134 USH patients to determine the presence of macular abnormalities, including cystoid macular edema (CME), epiretinal membrane (ERM), vitreo-macular traction syndrome (VMT), and macular hole (MH). Macular abnormalities were observed in 126/268 (47.0%) examined eyes. The most frequent abnormality was ERM observed in 51 eyes (19%), followed by CME observed in 42 eyes (15.7%). Moreover, CME was significantly (p < 0.05) associated with younger age (CME: 30.1 ± 11.1 years; without CME: 36.9 ± 14.9 years), whereas VMT and full thickness MH were associated with older age (p < 0.05). Moreover, a significantly (p < 0.05) decreased best-corrected visual acuity was associated with MH compared to eyes without MH. Finally, CME was more frequent in USH1 compared to USH2. Our study, for the first time in the literature, showed the distribution of all macular abnormalities assessed by SD-OCT in a large USH cohort, comparing USH1 and USH2 patients. We observed that ocular abnormalities are highly prevalent in USH patients compared to general population, with ERM and CME being the most common alterations. Based on these findings, OCT screening in USH patients is recommended for early detection of macular changes and early treatment.

  19. Online Support: Impact on Anxiety in Women Who Experience an Abnormal Screening Mammogram

    PubMed Central

    Obadina, Eniola T.; Dubenske, Lori L.; McDowell, Helene E.; Atwood, Amy K.; Mayer, Deborah K.; Woods, Ryan W.; Gustafson, David H.; Burnside, Elizabeth S.

    2014-01-01

    OBJECTIVES To determine whether an online support tool can impact anxiety in women experiencing an abnormal mammogram. MATERIALS AND METHODS We developed an online support system using the Comprehensive Health Enhancement Support System (CHESS) designed for women experiencing an abnormal mammogram as a model. Our trial randomized 130 of these women to online support (the intervention group) or to a list of five commonly used Internet sites (the comparison group). Surveys assessed anxiety and breast cancer worry, and patient satisfaction at three important clinical time points: when women were notified of their abnormal mammogram, at the time of diagnostic imaging, and at the time of biopsy (if biopsy was recommended). RESULTS Study participants in the intervention group showed a significant decrease in anxiety at the time of biopsy compared to the comparison group (p=0.017). However, there was no significant difference in anxiety between the intervention group and the comparison group at the time of diagnostic work-up. We discontinued assessment of patient satisfaction after finding that many women had substantial difficulty answering the questions that referenced their physician, because they did not understand who their physician was for this process of care. CONCLUSION The combination of the inability to identify the physician providing care during the mammography work-up and anxiety effects seen only after an interaction with the breast imaging team may indicate that online support only decreases the anxiety of women in concert with direct interpersonal support from the healthcare team. PMID:25193424

  20. Online support: Impact on anxiety in women who experience an abnormal screening mammogram.

    PubMed

    Obadina, Eniola T; Dubenske, Lori L; McDowell, Helene E; Atwood, Amy K; Mayer, Deborah K; Woods, Ryan W; Gustafson, David H; Burnside, Elizabeth S

    2014-12-01

    To determine whether an online support tool can impact anxiety in women experiencing an abnormal mammogram. We developed an online support system using the Comprehensive Health Enhancement Support System (CHESS) designed for women experiencing an abnormal mammogram as a model. Our trial randomized 130 of these women to online support (the intervention group) or to a list of five commonly used Internet sites (the comparison group). Surveys assessed anxiety and breast cancer worry, and patient satisfaction at three important clinical time points: when women were notified of their abnormal mammogram, at the time of diagnostic imaging, and at the time of biopsy (if biopsy was recommended). Study participants in the intervention group showed a significant decrease in anxiety at the time of biopsy compared to the comparison group (p = 0.017). However, there was no significant difference in anxiety between the intervention group and the comparison group at the time of diagnostic work-up. We discontinued assessment of patient satisfaction after finding that many women had substantial difficulty answering the questions that referenced their physician, because they did not understand who their physician was for this process of care. The combination of the inability to identify the physician providing care during the mammography work-up and anxiety effects seen only after an interaction with the breast imaging team may indicate that online support only decreases the anxiety of women in concert with direct interpersonal support from the healthcare team. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Abnormal functional motor lateralization in healthy siblings of patients with schizophrenia.

    PubMed

    Altamura, Mario; Fazio, Leonardo; De Salvia, Michela; Petito, Annamaria; Blasi, Giuseppe; Taurisano, Paolo; Romano, Raffaella; Gelao, Barbara; Bellomo, Antonello; Bertolino, Alessandro

    2012-07-30

    Earlier neuroimaging studies of motor function in schizophrenia have demonstrated reduced functional lateralization in the motor network during motor tasks. Here, we used event-related functional magnetic resonance imaging during a visually guided motor task in 18 clinically unaffected siblings of patients with schizophrenia and 24 matched controls to investigate if abnormal functional lateralization is related to genetic risk for this brain disorder. Whereas activity associated with motor task performance was mainly contralateral with only a marginal ipsilateral component in healthy participants, unaffected siblings had strong bilateral activity with significantly greater response in ipsilateral and contralateral premotor areas as well as in contralateral subcortical motor regions relative to controls. Reduced lateralization in siblings was also identified with a measure of laterality quotient. These findings suggest that abnormal functional lateralization of motor circuitry is related to genetic risk of schizophrenia. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  2. Abnormal Uterine Bleeding FAQ

    MedlinePlus

    ... Abnormal Uterine Bleeding • What is a normal menstrual cycle? • When is bleeding abnormal? • At what ages is ... abnormal bleeding? •Glossary What is a normal menstrual cycle? The normal length of the menstrual cycle is ...

  3. Translating the Verbal to the Visual

    ERIC Educational Resources Information Center

    Engbers, Susanna Kelly

    2012-01-01

    Communication has always been at least partly a visual experience--insofar as the speaker's appearance on a stage or the text's appearance on the page. Certainly, however, the experience is becoming more and more visual. Thus, equipping students with the tools necessary to analyze and evaluate the visual rhetoric that surrounds everyone is a task…

  4. Cortical thickness abnormalities associated with dyslexia, independent of remediation status.

    PubMed

    Ma, Yizhou; Koyama, Maki S; Milham, Michael P; Castellanos, F Xavier; Quinn, Brian T; Pardoe, Heath; Wang, Xiuyuan; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas; Blackmon, Karen

    2015-01-01

    Abnormalities in cortical structure are commonly observed in children with dyslexia in key regions of the "reading network." Whether alteration in cortical features reflects pathology inherent to dyslexia or environmental influence (e.g., impoverished reading experience) remains unclear. To address this question, we compared MRI-derived metrics of cortical thickness (CT), surface area (SA), gray matter volume (GMV), and their lateralization across three different groups of children with a historical diagnosis of dyslexia, who varied in current reading level. We compared three dyslexia subgroups with: (1) persistent reading and spelling impairment; (2) remediated reading impairment (normal reading scores), and (3) remediated reading and spelling impairments (normal reading and spelling scores); and a control group of (4) typically developing children. All groups were matched for age, gender, handedness, and IQ. We hypothesized that the dyslexia group would show cortical abnormalities in regions of the reading network relative to controls, irrespective of remediation status. Such a finding would support that cortical abnormalities are inherent to dyslexia and are not a consequence of abnormal reading experience. Results revealed increased CT of the left fusiform gyrus in the dyslexia group relative to controls. Similarly, the dyslexia group showed CT increase of the right superior temporal gyrus, extending into the planum temporale, which resulted in a rightward CT asymmetry on lateralization indices. There were no group differences in SA, GMV, or their lateralization. These findings held true regardless of remediation status. Each reading level group showed the same "double hit" of atypically increased left fusiform CT and rightward superior temporal CT asymmetry. Thus, findings provide evidence that a developmental history of dyslexia is associated with CT abnormalities, independent of remediation status.

  5. Multisensory training can promote or impede visual perceptual learning of speech stimuli: visual-tactile vs. visual-auditory training.

    PubMed

    Eberhardt, Silvio P; Auer, Edward T; Bernstein, Lynne E

    2014-01-01

    In a series of studies we have been investigating how multisensory training affects unisensory perceptual learning with speech stimuli. Previously, we reported that audiovisual (AV) training with speech stimuli can promote auditory-only (AO) perceptual learning in normal-hearing adults but can impede learning in congenitally deaf adults with late-acquired cochlear implants. Here, impeder and promoter effects were sought in normal-hearing adults who participated in lipreading training. In Experiment 1, visual-only (VO) training on paired associations between CVCVC nonsense word videos and nonsense pictures demonstrated that VO words could be learned to a high level of accuracy even by poor lipreaders. In Experiment 2, visual-auditory (VA) training in the same paradigm but with the addition of synchronous vocoded acoustic speech impeded VO learning of the stimuli in the paired-associates paradigm. In Experiment 3, the vocoded AO stimuli were shown to be less informative than the VO speech. Experiment 4 combined vibrotactile speech stimuli with the visual stimuli during training. Vibrotactile stimuli were shown to promote visual perceptual learning. In Experiment 5, no-training controls were used to show that training with visual speech carried over to consonant identification of untrained CVCVC stimuli but not to lipreading words in sentences. Across this and previous studies, multisensory training effects depended on the functional relationship between pathways engaged during training. Two principles are proposed to account for stimulus effects: (1) Stimuli presented to the trainee's primary perceptual pathway will impede learning by a lower-rank pathway. (2) Stimuli presented to the trainee's lower rank perceptual pathway will promote learning by a higher-rank pathway. The mechanisms supporting these principles are discussed in light of multisensory reverse hierarchy theory (RHT).

  6. Multisensory training can promote or impede visual perceptual learning of speech stimuli: visual-tactile vs. visual-auditory training

    PubMed Central

    Eberhardt, Silvio P.; Auer Jr., Edward T.; Bernstein, Lynne E.

    2014-01-01

    In a series of studies we have been investigating how multisensory training affects unisensory perceptual learning with speech stimuli. Previously, we reported that audiovisual (AV) training with speech stimuli can promote auditory-only (AO) perceptual learning in normal-hearing adults but can impede learning in congenitally deaf adults with late-acquired cochlear implants. Here, impeder and promoter effects were sought in normal-hearing adults who participated in lipreading training. In Experiment 1, visual-only (VO) training on paired associations between CVCVC nonsense word videos and nonsense pictures demonstrated that VO words could be learned to a high level of accuracy even by poor lipreaders. In Experiment 2, visual-auditory (VA) training in the same paradigm but with the addition of synchronous vocoded acoustic speech impeded VO learning of the stimuli in the paired-associates paradigm. In Experiment 3, the vocoded AO stimuli were shown to be less informative than the VO speech. Experiment 4 combined vibrotactile speech stimuli with the visual stimuli during training. Vibrotactile stimuli were shown to promote visual perceptual learning. In Experiment 5, no-training controls were used to show that training with visual speech carried over to consonant identification of untrained CVCVC stimuli but not to lipreading words in sentences. Across this and previous studies, multisensory training effects depended on the functional relationship between pathways engaged during training. Two principles are proposed to account for stimulus effects: (1) Stimuli presented to the trainee’s primary perceptual pathway will impede learning by a lower-rank pathway. (2) Stimuli presented to the trainee’s lower rank perceptual pathway will promote learning by a higher-rank pathway. The mechanisms supporting these principles are discussed in light of multisensory reverse hierarchy theory (RHT). PMID:25400566

  7. Abnormal GABAergic function and face processing in schizophrenia: A pharmacologic-fMRI study.

    PubMed

    Tso, Ivy F; Fang, Yu; Phan, K Luan; Welsh, Robert C; Taylor, Stephan F

    2015-10-01

    The involvement of the gamma-aminobutyric acid (GABA) system in schizophrenia is suggested by postmortem studies and the common use of GABA receptor-potentiating agents in treatment. In a recent study, we used a benzodiazepine challenge to demonstrate abnormal GABAergic function during processing of negative visual stimuli in schizophrenia. This study extended this investigation by mapping GABAergic mechanisms associated with face processing and social appraisal in schizophrenia using a benzodiazepine challenge. Fourteen stable, medicated schizophrenia/schizoaffective patients (SZ) and 13 healthy controls (HC) underwent functional MRI using the blood oxygenation level-dependent (BOLD) technique while they performed the Socio-emotional Preference Task (SePT) on emotional face stimuli ("Do you like this face?"). Participants received single-blinded intravenous saline and lorazepam (LRZ) in two separate sessions separated by 1-3weeks. Both SZ and HC recruited medial prefrontal cortex/anterior cingulate during the SePT, relative to gender identification. A significant drug by group interaction was observed in the medial occipital cortex, such that SZ showed increased BOLD signal to LRZ challenge, while HC showed an expected decrease of signal; the interaction did not vary by task. The altered BOLD response to LRZ challenge in SZ was significantly correlated with increased negative affect across multiple measures. The altered response to LRZ challenge suggests that abnormal face processing and negative affect in SZ are associated with altered GABAergic function in the visual cortex, underscoring the role of impaired visual processing in socio-emotional deficits in schizophrenia. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Abnormal tuning of saccade-related cells in pontine reticular formation of strabismic monkeys.

    PubMed

    Walton, Mark M G; Mustari, Michael J

    2015-08-01

    Strabismus is a common disorder, characterized by a chronic misalignment of the eyes and numerous visual and oculomotor abnormalities. For example, saccades are often highly disconjugate. For humans with pattern strabismus, the horizontal and vertical disconjugacies vary with eye position. In monkeys, manipulations that disturb binocular vision during the first several weeks of life result in a chronic strabismus with characteristics that closely match those in human patients. Early onset strabismus is associated with altered binocular sensitivity of neurons in visual cortex. Here we test the hypothesis that brain stem circuits specific to saccadic eye movements are abnormal. We targeted the pontine paramedian reticular formation, a structure that directly projects to the ipsilateral abducens nucleus. In normal animals, neurons in this structure are characterized by a high-frequency burst of spikes associated with ipsiversive saccades. We recorded single-unit activity from 84 neurons from four monkeys (two normal, one exotrope, and one esotrope), while they made saccades to a visual target on a tangent screen. All 24 neurons recorded from the normal animals had preferred directions within 30° of pure horizontal. For the strabismic animals, the distribution of preferred directions was normal on one side of the brain, but highly variable on the other. In fact, 12/60 neurons recorded from the strabismic animals preferred vertical saccades. Many also had unusually weak or strong bursts. These data suggest that the loss of corresponding binocular vision during infancy impairs the development of normal tuning characteristics for saccade-related neurons in brain stem. Copyright © 2015 the American Physiological Society.

  9. Effect of abnormal notochord delamination on hindgut development in the Adriamycin mouse model.

    PubMed

    Sato, Hideaki; Hajduk, Piotr; Furuta, Shigeyuki; Wakisaka, Munechika; Murphy, Paula; Puri, Prem; Kitagawa, Hiroaki

    2013-11-01

    Adriamycin mouse model (AMM) is a model of VACTERL anomalies. Sonic hedgehog (Shh) pathway, sourced by the notochord, is implicated of anorectal malformations. We hypothesized hindgut anomalies observed in the AMM are the result of abnormal effect of the notochord. Time-mated CBA/Ca mice received two intraperitoneal injections of Adriamycin (6 mg/kg) or saline as control on embryonic day (E) 7 and 8. Fetuses were harvested from E9 to E11, stained following whole mount in situ hybridization with labeled RNA probes to detect Shh and Fork head box F1(Foxf1) transcripts. Immunolocalization with endoderm marker Hnf3β was used to visualize morphology. Embryos were scanned by OPT to obtain 3D representations of expressions. In AMM, the notochord was abnormally displaced ventrally with attachment to the hindgut endoderm in 71 % of the specimens. In 32 % of the treated embryos abnormal hindgut ended blindly in a cystic structure, and both of types were remarked in 29 % of treated embryos. Endodermal Shh and mesenchymal Foxf1 genes expression were preserved around the hindgut cystic malformation. The delamination of the developing notochord in the AMM is disrupted, which may influence signaling mechanisms from the notochord to the hindgut resulting in abnormal patterning of the hindgut.

  10. Temporal lobe developmental malformations and epilepsy: dual pathology and bilateral hippocampal abnormalities.

    PubMed

    Ho, S S; Kuzniecky, R I; Gilliam, F; Faught, E; Morawetz, R

    1998-03-01

    Temporal lobe developmental malformations (TLDM) with focal cortical dysplasia and balloon cells may coexist with mesial temporal sclerosis. The true incidence of this dual pathology is unknown. Our aim was to assess the frequency of amygdala (AM)-hippocampal abnormality in a homogeneous population with this specific developmental malformation. MRI-based volumetry of the AM and hippocampal formation (HF) in 30 patients with unilateral TLDM and intractable partial epilepsy was performed. A volume normalization process defined a normal range of HF and AM volumes in control subjects, and enabled the detection of bilateral volume loss. Normalized volumes detected HF atrophy in 26 patients (nine unilateral and 17 bilateral) and AM atrophy in 18 patients (three unilateral and 15 bilateral). Visual analysis detected unilateral HF abnormality in 21 patients and bilateral abnormality in two. When compared with a group of patients with temporal lobe epilepsy and pure hippocampal sclerosis (N = 92), where volumetry revealed bilateral HF atrophy in 18%, a significant difference in the frequency of bilateral HF atrophy was found (p < 0.0001). Dual pathology is frequent in patients with TLDM (87%), and the AM-HF abnormality is often bilateral (57%). Our data suggest that more widespread and potentially epileptogenic lesions coexist with visibly detectable unilateral TLDM. This has implications for the selection of patients for temporal lobe surgery and may influence surgical strategies.

  11. Urine - abnormal color

    MedlinePlus

    ... medlineplus.gov/ency/article/003139.htm Urine - abnormal color To use the sharing features on this page, please enable JavaScript. The usual color of urine is straw-yellow. Abnormally colored urine ...

  12. The Efficiency of a Visual Skills Training Program on Visual Search Performance

    PubMed Central

    Krzepota, Justyna; Zwierko, Teresa; Puchalska-Niedbał, Lidia; Markiewicz, Mikołaj; Florkiewicz, Beata; Lubiński, Wojciech

    2015-01-01

    In this study, we conducted an experiment in which we analyzed the possibilities to develop visual skills by specifically targeted training of visual search. The aim of our study was to investigate whether, for how long and to what extent a training program for visual functions could improve visual search. The study involved 24 healthy students from the Szczecin University who were divided into two groups: experimental (12) and control (12). In addition to regular sports and recreational activities of the curriculum, the subjects of the experimental group also participated in 8-week long training with visual functions, 3 times a week for 45 min. The Signal Test of the Vienna Test System was performed four times: before entering the study, after first 4 weeks of the experiment, immediately after its completion and 4 weeks after the study terminated. The results of this experiment proved that an 8-week long perceptual training program significantly differentiated the plot of visual detecting time. For the visual detecting time changes, the first factor, Group, was significant as a main effect (F(1,22)=6.49, p<0.05) as well as the second factor, Training (F(3,66)=5.06, p<0.01). The interaction between the two factors (Group vs. Training) of perceptual training was F(3,66)=6.82 (p<0.001). Similarly, for the number of correct reactions, there was a main effect of a Group factor (F(1,22)=23.40, p<0.001), a main effect of a Training factor (F(3,66)=11.60, p<0.001) and a significant interaction between factors (Group vs. Training) (F(3,66)=10.33, p<0.001). Our study suggests that 8-week training of visual functions can improve visual search performance. PMID:26240666

  13. Scanning laser polarimetry, but not optical coherence tomography predicts permanent visual field loss in acute nonarteritic anterior ischemic optic neuropathy.

    PubMed

    Kupersmith, Mark J; Anderson, Susan; Durbin, Mary; Kardon, Randy

    2013-08-15

    Scanning laser polarimetry (SLP) reveals abnormal retardance of birefringence in locations of the edematous peripapillary retinal nerve fiber layer (RNFL), which appear thickened by optical coherence tomography (OCT), in nonarteritic anterior ischemic optic neuropathy (NAION). We hypothesize initial sector SLP RNFL abnormalities will correlate with long-term regional visual field loss due to ischemic injury. We prospectively performed automated perimetry, SLP, and high definition OCT (HD-OCT) of the RNFL in 25 eyes with acute NAION. We grouped visual field threshold and RNFL values into Garway-Heath inferior/superior disc sectors and corresponding superior/inferior field regions. We compared sector SLP RNFL thickness with corresponding visual field values at presentation and at >3 months. At presentation, 12 eyes had superior sector SLP reduction, 11 of which had inferior field loss. Six eyes, all with superior field loss, had inferior sector SLP reduction. No eyes had reduced OCT-derived RNFL acutely. Eyes with abnormal field regions had corresponding SLP sectors thinner (P = 0.003) than for sectors with normal field regions. During the acute phase, the SLP-derived sector correlated with presentation (r = 0.59, P = 0.02) and with >3-month after presentation (r = 0.44, P = 0.02) corresponding superior and inferior field thresholds. Abnormal RNFL birefringence occurs in sectors corresponding to regional visual field loss during acute NAION when OCT-derived RNFL shows thickening. Since the visual field deficits show no significant recovery, SLP can be an early marker for axonal injury, which may be used to assess recovery potential at RNFL locations with respect to new treatments for acute NAION.

  14. Abnormal sleep/wake dynamics in orexin knockout mice.

    PubMed

    Diniz Behn, Cecilia G; Klerman, Elizabeth B; Mochizuki, Takatoshi; Lin, Shih-Chieh; Scammell, Thomas E

    2010-03-01

    Narcolepsy with cataplexy is caused by a loss of orexin (hypocretin) signaling, but the physiologic mechanisms that result in poor maintenance of wakefulness and fragmented sleep remain unknown. Conventional scoring of sleep cannot reveal much about the process of transitioning between states or the variations within states. We developed an EEG spectral analysis technique to determine whether the state instability in a mouse model of narcolepsy reflects abnormal sleep or wake states, faster movements between states, or abnormal transitions between states. We analyzed sleep recordings in orexin knockout (OXKO) mice and wild type (WT) littermates using a state space analysis technique. This non-categorical approach allows quantitative and unbiased examination of sleep/wake states and state transitions. OXKO mice spent less time in deep, delta-rich NREM sleep and in active, theta-rich wake and instead spent more time near the transition zones between states. In addition, while in the midst of what should be stable wake, OXKO mice initiated rapid changes into NREM sleep with high velocities normally seen only in transition regions. Consequently, state transitions were much more frequent and rapid even though the EEG progressions during state transitions were normal. State space analysis enables visualization of the boundaries between sleep and wake and shows that narcoleptic mice have less distinct and more labile states of sleep and wakefulness. These observations provide new perspectives on the abnormal state dynamics resulting from disrupted orexin signaling and highlight the usefulness of state space analysis in understanding narcolepsy and other sleep disorders.

  15. A Robotics-Based Approach to Modeling of Choice Reaching Experiments on Visual Attention

    PubMed Central

    Strauss, Soeren; Heinke, Dietmar

    2012-01-01

    The paper presents a robotics-based model for choice reaching experiments on visual attention. In these experiments participants were asked to make rapid reach movements toward a target in an odd-color search task, i.e., reaching for a green square among red squares and vice versa (e.g., Song and Nakayama, 2008). Interestingly these studies found that in a high number of trials movements were initially directed toward a distractor and only later were adjusted toward the target. These “curved” trajectories occurred particularly frequently when the target in the directly preceding trial had a different color (priming effect). Our model is embedded in a closed-loop control of a LEGO robot arm aiming to mimic these reach movements. The model is based on our earlier work which suggests that target selection in visual search is implemented through parallel interactions between competitive and cooperative processes in the brain (Heinke and Humphreys, 2003; Heinke and Backhaus, 2011). To link this model with the control of the robot arm we implemented a topological representation of movement parameters following the dynamic field theory (Erlhagen and Schoener, 2002). The robot arm is able to mimic the results of the odd-color search task including the priming effect and also generates human-like trajectories with a bell-shaped velocity profile. Theoretical implications and predictions are discussed in the paper. PMID:22529827

  16. Effects of abnormal light-rearing conditions on retinal physiology in larvae zebrafish.

    PubMed

    Saszik, S; Bilotta, J

    1999-11-01

    Anatomic studies have found that zebrafish retinal neurons develop in a sequential fashion. In addition, exposure to abnormal light-rearing conditions produces deficits in visual behavior of larvae zebrafish, even though there appears to be little effect of the light-rearing conditions on the gross morphology of the retina. The purpose of this study was to assess the effects of abnormal light-rearing conditions on larvae zebrafish retinal physiology. Larvae zebrafish (Danio rerio) were exposed to constant light (LL), constant dark (DD), or normal cyclic light (LD) from fertilization to 6 days postfertilization (dpf). After 6 days, the animals were placed into normal cyclic light and tested at 6 to 8, 13 to 15, and 21 to 24 dpf. Electroretinogram (ERG) responses to visual stimuli, consisting of various wavelengths and irradiances, were recorded. Comparisons were made across the three age groups and the three light-rearing conditions. Deficits from the light-rearing conditions were seen immediately after exposure (6 8 dpf). The LL-condition subjects showed the greatest deficit in the UV and short-wavelength areas and the DD-condition subjects showed a slight deficit across the entire spectrum. At 13 to 15 dpf, the LL and DD groups showed an increase in sensitivity and by 21 to 24 dpf, the groups no longer differed from controls. Abnormal lighting environments can adversely influence the physiological development of the larvae zebrafish retina. The pattern of damage that was seen in zebrafish is similar to that found in other vertebrates, including higher vertebrates. However, unlike higher vertebrates, the zebrafish appears to be capable of regeneration. This suggests that the zebrafish would be a viable model for light environment effects and neural regeneration.

  17. Experiences of Students with Visual Impairments in Adoption of Digital Talking Textbooks: An Interpretative Phenomenological Analysis

    ERIC Educational Resources Information Center

    Hussin, Ahamad; Folkestad, James E.; Makela, Carole

    2013-01-01

    This study was conducted to explore the experiences of Malaysian secondary students with visual impairments in using digital talking textbooks (DTTs) to assist their learning. Data were obtained from individual in-depth interviews. An interpretative phenomenological analysis (IPA) was used to understand the findings and confirm the emergent…

  18. Experiences of Students with Visual Impairments in Adoption of Digital Talking Textbooks: An Interpretative Phenomenological Analysis

    ERIC Educational Resources Information Center

    Hussin, Ahamad

    2013-01-01

    Assistive technology devices have become essential tools for students with visual impairments. In 2009, the Malaysian Ministry of Education introduced Digital Talking Textbooks (DTTs) for selected subjects to facilitate learning. The purpose of this qualitative study was to explore, describe, and interpret the experiences of students with visual…

  19. VISUAL3D - An EIT network on visualization of geomodels

    NASA Astrophysics Data System (ADS)

    Bauer, Tobias

    2017-04-01

    When it comes to interpretation of data and understanding of deep geological structures and bodies at different scales then modelling tools and modelling experience is vital for deep exploration. Geomodelling provides a platform for integration of different types of data, including new kinds of information (e.g., new improved measuring methods). EIT Raw Materials, initiated by the EIT (European Institute of Innovation and Technology) and funded by the European Commission, is the largest and strongest consortium in the raw materials sector worldwide. The VISUAL3D network of infrastructure is an initiative by EIT Raw Materials and aims at bringing together partners with 3D-4D-visualisation infrastructure and 3D-4D-modelling experience. The recently formed network collaboration interlinks hardware, software and expert knowledge in modelling visualization and output. A special focus will be the linking of research, education and industry and integrating multi-disciplinary data and to visualize the data in three and four dimensions. By aiding network collaborations we aim at improving the combination of geomodels with differing file formats and data characteristics. This will create an increased competency in modelling visualization and the ability to interchange and communicate models more easily. By combining knowledge and experience in geomodelling with expertise in Virtual Reality visualization partners of EIT Raw Materials but also external parties will have the possibility to visualize, analyze and validate their geomodels in immersive VR-environments. The current network combines partners from universities, research institutes, geological surveys and industry with a strong background in geological 3D-modelling and 3D visualization and comprises: Luleå University of Technology, Geological Survey of Finland, Geological Survey of Denmark and Greenland, TUBA Freiberg, Uppsala University, Geological Survey of France, RWTH Aachen, DMT, KGHM Cuprum, Boliden, Montan

  20. CAFE: an R package for the detection of gross chromosomal abnormalities from gene expression microarray data.

    PubMed

    Bollen, Sander; Leddin, Mathias; Andrade-Navarro, Miguel A; Mah, Nancy

    2014-05-15

    The current methods available to detect chromosomal abnormalities from DNA microarray expression data are cumbersome and inflexible. CAFE has been developed to alleviate these issues. It is implemented as an R package that analyzes Affymetrix *.CEL files and comes with flexible plotting functions, easing visualization of chromosomal abnormalities. CAFE is available from https://bitbucket.org/cob87icW6z/cafe/ as both source and compiled packages for Linux and Windows. It is released under the GPL version 3 license. CAFE will also be freely available from Bioconductor. sander.h.bollen@gmail.com or nancy.mah@mdc-berlin.de Supplementary data are available at Bioinformatics online.

  1. Changes of Visual Pathway and Brain Connectivity in Glaucoma: A Systematic Review

    PubMed Central

    Nuzzi, Raffaele; Dallorto, Laura; Rolle, Teresa

    2018-01-01

    Background: Glaucoma is a leading cause of irreversible blindness worldwide. The increasing interest in the involvement of the cortical visual pathway in glaucomatous patients is due to the implications in recent therapies, such as neuroprotection and neuroregeneration. Objective: In this review, we outline the current understanding of brain structural, functional, and metabolic changes detected with the modern techniques of neuroimaging in glaucomatous subjects. Methods: We screened MEDLINE, EMBASE, CINAHL, CENTRAL, LILACS, Trip Database, and NICE for original contributions published until 31 October 2017. Studies with at least six patients affected by any type of glaucoma were considered. We included studies using the following neuroimaging techniques: functional Magnetic Resonance Imaging (fMRI), resting-state fMRI (rs-fMRI), magnetic resonance spectroscopy (MRS), voxel- based Morphometry (VBM), surface-based Morphometry (SBM), diffusion tensor MRI (DTI). Results: Over a total of 1,901 studies, 56 case series with a total of 2,381 patients were included. Evidence of neurodegenerative process in glaucomatous patients was found both within and beyond the visual system. Structural alterations in visual cortex (mainly reduced cortex thickness and volume) have been demonstrated with SBM and VBM; these changes were not limited to primary visual cortex but also involved association visual areas. Other brain regions, associated with visual function, demonstrated a certain grade of increased or decreased gray matter volume. Functional and metabolic abnormalities resulted within primary visual cortex in all studies with fMRI and MRS. Studies with rs-fMRI found disrupted connectivity between the primary and higher visual cortex and between visual cortex and associative visual areas in the task-free state of glaucomatous patients. Conclusions: This review contributes to the better understanding of brain abnormalities in glaucoma. It may stimulate further speculation about

  2. Trained Eyes: Experience Promotes Adaptive Gaze Control in Dynamic and Uncertain Visual Environments

    PubMed Central

    Taya, Shuichiro; Windridge, David; Osman, Magda

    2013-01-01

    Current eye-tracking research suggests that our eyes make anticipatory movements to a location that is relevant for a forthcoming task. Moreover, there is evidence to suggest that with more practice anticipatory gaze control can improve. However, these findings are largely limited to situations where participants are actively engaged in a task. We ask: does experience modulate anticipative gaze control while passively observing a visual scene? To tackle this we tested people with varying degrees of experience of tennis, in order to uncover potential associations between experience and eye movement behaviour while they watched tennis videos. The number, size, and accuracy of saccades (rapid eye-movements) made around ‘events,’ which is critical for the scene context (i.e. hit and bounce) were analysed. Overall, we found that experience improved anticipatory eye-movements while watching tennis clips. In general, those with extensive experience showed greater accuracy of saccades to upcoming event locations; this was particularly prevalent for events in the scene that carried high uncertainty (i.e. ball bounces). The results indicate that, even when passively observing, our gaze control system utilizes prior relevant knowledge in order to anticipate upcoming uncertain event locations. PMID:23951147

  3. Normal Visual Acuity and Electrophysiological Contrast Gain in Adults with High-Functioning Autism Spectrum Disorder.

    PubMed

    Tebartz van Elst, Ludger; Bach, Michael; Blessing, Julia; Riedel, Andreas; Bubl, Emanuel

    2015-01-01

    A common neurodevelopmental disorder, autism spectrum disorder (ASD), is defined by specific patterns in social perception, social competence, communication, highly circumscribed interests, and a strong subjective need for behavioral routines. Furthermore, distinctive features of visual perception, such as markedly reduced eye contact and a tendency to focus more on small, visual items than on holistic perception, have long been recognized as typical ASD characteristics. Recent debate in the scientific community discusses whether the physiology of low-level visual perception might explain such higher visual abnormalities. While reports of this enhanced, "eagle-like" visual acuity contained methodological errors and could not be substantiated, several authors have reported alterations in even earlier stages of visual processing, such as contrast perception and motion perception at the occipital cortex level. Therefore, in this project, we have investigated the electrophysiology of very early visual processing by analyzing the pattern electroretinogram-based contrast gain, the background noise amplitude, and the psychophysical visual acuities of participants with high-functioning ASD and controls with equal education. Based on earlier findings, we hypothesized that alterations in early vision would be present in ASD participants. This study included 33 individuals with ASD (11 female) and 33 control individuals (12 female). The groups were matched in terms of age, gender, and education level. We found no evidence of altered electrophysiological retinal contrast processing or psychophysical measured visual acuities. There appears to be no evidence for abnormalities in retinal visual processing in ASD patients, at least with respect to contrast detection.

  4. Beauty and the beholder: the role of visual sensitivity in visual preference

    PubMed Central

    Spehar, Branka; Wong, Solomon; van de Klundert, Sarah; Lui, Jessie; Clifford, Colin W. G.; Taylor, Richard P.

    2015-01-01

    For centuries, the essence of aesthetic experience has remained one of the most intriguing mysteries for philosophers, artists, art historians and scientists alike. Recently, views emphasizing the link between aesthetics, perception and brain function have become increasingly prevalent (Ramachandran and Hirstein, 1999; Zeki, 1999; Livingstone, 2002; Ishizu and Zeki, 2013). The link between art and the fractal-like structure of natural images has also been highlighted (Spehar et al., 2003; Graham and Field, 2007; Graham and Redies, 2010). Motivated by these claims and our previous findings that humans display a consistent preference across various images with fractal-like statistics, here we explore the possibility that observers’ preference for visual patterns might be related to their sensitivity for such patterns. We measure sensitivity to simple visual patterns (sine-wave gratings varying in spatial frequency and random textures with varying scaling exponent) and find that they are highly correlated with visual preferences exhibited by the same observers. Although we do not attempt to offer a comprehensive neural model of aesthetic experience, we demonstrate a strong relationship between visual sensitivity and preference for simple visual patterns. Broadly speaking, our results support assertions that there is a close relationship between aesthetic experience and the sensory coding of natural stimuli. PMID:26441611

  5. Ophthalmological, Cognitive, Electrophysiological and MRI Assessment of Visual Processing in Preterm Children without Major Neuromotor Impairment

    ERIC Educational Resources Information Center

    O'Reilly, Michelle; Vollmer, Brigitte; Vargha-Khadem, Faraneh; Neville, Brian; Connelly, Alan; Wyatt, John; Timms, Chris; De Haan, Michelle

    2010-01-01

    Many studies report chronic deficits in visual processing in children born preterm. We investigated whether functional abnormalities in visual processing exist in children born preterm but without major neuromotor impairment (i.e. cerebral palsy). Twelve such children (less than 33 weeks gestation or birthweight less than 1000 g) without major…

  6. CompGO: an R package for comparing and visualizing Gene Ontology enrichment differences between DNA binding experiments.

    PubMed

    Waardenberg, Ashley J; Basset, Samuel D; Bouveret, Romaric; Harvey, Richard P

    2015-09-02

    Gene ontology (GO) enrichment is commonly used for inferring biological meaning from systems biology experiments. However, determining differential GO and pathway enrichment between DNA-binding experiments or using the GO structure to classify experiments has received little attention. Herein, we present a bioinformatics tool, CompGO, for identifying Differentially Enriched Gene Ontologies, called DiEGOs, and pathways, through the use of a z-score derivation of log odds ratios, and visualizing these differences at GO and pathway level. Through public experimental data focused on the cardiac transcription factor NKX2-5, we illustrate the problems associated with comparing GO enrichments between experiments using a simple overlap approach. We have developed an R/Bioconductor package, CompGO, which implements a new statistic normally used in epidemiological studies for performing comparative GO analyses and visualizing comparisons from . BED data containing genomic coordinates as well as gene lists as inputs. We justify the statistic through inclusion of experimental data and compare to the commonly used overlap method. CompGO is freely available as a R/Bioconductor package enabling easy integration into existing pipelines and is available at: http://www.bioconductor.org/packages/release/bioc/html/CompGO.html packages/release/bioc/html/CompGO.html.

  7. Hemispheric Specialization for Language According to Grapho-Phonemic Transformation and Gender. A Divided Visual Field Experiment

    ERIC Educational Resources Information Center

    Cousin, Emilie; Perrone, Marcela; Baciu, Monica

    2009-01-01

    This behavioral study aimed at assessing the effect of two variables on the degree of hemispheric specialization for language. One of them was the "grapho-phonemic translation (transformation)" (letter-sound mapping) and the other was the participants' "gender". The experiment was conducted with healthy volunteers. A divided visual field procedure…

  8. Cortical thickness abnormalities associated with dyslexia, independent of remediation status

    PubMed Central

    Ma, Yizhou; Koyama, Maki S.; Milham, Michael P.; Castellanos, F. Xavier; Quinn, Brian T.; Pardoe, Heath; Wang, Xiuyuan; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas; Blackmon, Karen

    2014-01-01

    Abnormalities in cortical structure are commonly observed in children with dyslexia in key regions of the “reading network.” Whether alteration in cortical features reflects pathology inherent to dyslexia or environmental influence (e.g., impoverished reading experience) remains unclear. To address this question, we compared MRI-derived metrics of cortical thickness (CT), surface area (SA), gray matter volume (GMV), and their lateralization across three different groups of children with a historical diagnosis of dyslexia, who varied in current reading level. We compared three dyslexia subgroups with: (1) persistent reading and spelling impairment; (2) remediated reading impairment (normal reading scores), and (3) remediated reading and spelling impairments (normal reading and spelling scores); and a control group of (4) typically developing children. All groups were matched for age, gender, handedness, and IQ. We hypothesized that the dyslexia group would show cortical abnormalities in regions of the reading network relative to controls, irrespective of remediation status. Such a finding would support that cortical abnormalities are inherent to dyslexia and are not a consequence of abnormal reading experience. Results revealed increased CT of the left fusiform gyrus in the dyslexia group relative to controls. Similarly, the dyslexia group showed CT increase of the right superior temporal gyrus, extending into the planum temporale, which resulted in a rightward CT asymmetry on lateralization indices. There were no group differences in SA, GMV, or their lateralization. These findings held true regardless of remediation status. Each reading level group showed the same “double hit” of atypically increased left fusiform CT and rightward superior temporal CT asymmetry. Thus, findings provide evidence that a developmental history of dyslexia is associated with CT abnormalities, independent of remediation status. PMID:25610779

  9. Fifteen-minute consultation-the child with a developmental disability: is there an ocular or visual abnormality?

    PubMed

    Salt, Alison; Sargent, Jenefer

    2017-12-01

    To present a structured approach for an outpatient consultation for a child with developmental disability who may have an ocular or visual disorder. Review of relevant literature and description of the approach to ocular and visual assessment which could be used by any paediatrician. A systematic approach to history, observation and examination of a child with a developmental disability will assist in identifying a possible visual problem. A structured referral letter will ensure that the child will receive the most appropriate assessment to clarify the problem and appropriate management in the eye clinic. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  10. Normal or abnormal? 'Normative uncertainty' in psychiatric practice.

    PubMed

    Bassett, Andrew M; Baker, Charley

    2015-06-01

    The 'multicultural clinical interaction' presents itself as a dilemma for the mental health practitioner. Literature describes two problematic areas where this issues emerges--how to make an adequate distinction between religious rituals and the rituals that may be symptomatic of 'obsessive compulsive disorder' (OCD), and how to differentiate 'normative' religious or spiritual beliefs, behaviours, and experiences from 'psychotic' illnesses. When it comes to understanding service user's 'idioms of distress', beliefs about how culture influences behaviour can create considerable confusion and 'normative uncertainty' for mental health practitioners. In the absence of clear diagnostic and assessment criteria on distinguishing between 'culture' and 'psychopathology', practitioners have had to rely on their own intuition and seek out possible 'strategies' or 'procedures' from a contradictory and cross-disciplinary evidence base. Decontextualisation of service users' experiences may result in the pathologisation of culturally 'normative' phenomenon, 'category fallacy' errors, and poor health care experiences and outcomes for service users.This paper situates this dilemma within a wider debate that has concerned both the biomedical and social sciences, namely, the unresolved question of 'normality' or 'abnormality'. Indeed, issues that arise from dilemmas surrounding the question of 'culture' or 'psychopathology' are intimately tied to wider cultural ideas about what is considered 'normal'. The disciplines of psychiatry, psychology, and medical anthropology have struggled to establish workable criteria against which to judge behaviour as 'normal', 'abnormal', or 'pathological'. Three models for understanding mental 'abnormality' are evident in 'transcultural psychiatry' (what is now commonly known as 'cultural psychiatry'), and these models have corresponded closely to the interpretive models used by anthropologists attempting to make sense of the apparent diversity of

  11. Abnormal pressures as hydrodynamic phenomena

    USGS Publications Warehouse

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  12. Promoting Visual Literacy among Undergraduate Students in Geography: Teaching a Visualized Latin America

    ERIC Educational Resources Information Center

    Hollman, Verónica

    2014-01-01

    This study offers a discussion of the role of the visual in the professional training of geographers arguing that visual literacy is not necessarily promoted during geography undergraduate studies. It then analyzes an experience of teaching a visualized Latin America developed in Argentina, as an illustrative example: on the one hand, it reveals…

  13. Genome image programs: visualization and interpretation of Escherichia coli microarray experiments.

    PubMed

    Zimmer, Daniel P; Paliy, Oleg; Thomas, Brian; Gyaneshwar, Prasad; Kustu, Sydney

    2004-08-01

    We have developed programs to facilitate analysis of microarray data in Escherichia coli. They fall into two categories: manipulation of microarray images and identification of known biological relationships among lists of genes. A program in the first category arranges spots from glass-slide DNA microarrays according to their position in the E. coli genome and displays them compactly in genome order. The resulting genome image is presented in a web browser with an image map that allows the user to identify genes in the reordered image. Another program in the first category aligns genome images from two or more experiments. These images assist in visualizing regions of the genome with common transcriptional control. Such regions include multigene operons and clusters of operons, which are easily identified as strings of adjacent, similarly colored spots. The images are also useful for assessing the overall quality of experiments. The second category of programs includes a database and a number of tools for displaying biological information about many E. coli genes simultaneously rather than one gene at a time, which facilitates identifying relationships among them. These programs have accelerated and enhanced our interpretation of results from E. coli DNA microarray experiments. Examples are given. Copyright 2004 Genetics Society of America

  14. Fusing visual and behavioral cues for modeling user experience in games.

    PubMed

    Shaker, Noor; Asteriadis, Stylianos; Yannakakis, Georgios N; Karpouzis, Kostas

    2013-12-01

    Estimating affective and cognitive states in conditions of rich human-computer interaction, such as in games, is a field of growing academic and commercial interest. Entertainment and serious games can benefit from recent advances in the field as, having access to predictors of the current state of the player (or learner) can provide useful information for feeding adaptation mechanisms that aim to maximize engagement or learning effects. In this paper, we introduce a large data corpus derived from 58 participants that play the popular Super Mario Bros platform game and attempt to create accurate models of player experience for this game genre. Within the view of the current research, features extracted both from player gameplay behavior and game levels, and player visual characteristics have been used as potential indicators of reported affect expressed as pairwise preferences between different game sessions. Using neuroevolutionary preference learning and automatic feature selection, highly accurate models of reported engagement, frustration, and challenge are constructed (model accuracies reach 91%, 92%, and 88% for engagement, frustration, and challenge, respectively). As a step further, the derived player experience models can be used to personalize the game level to desired levels of engagement, frustration, and challenge as game content is mapped to player experience through the behavioral and expressivity patterns of each player.

  15. Caries experience and oral hygiene status of a group of visually impaired children in Istanbul, Turkey.

    PubMed

    Bekiroglu, Nural; Acar, Nihan; Kargul, Betul

    2012-01-01

    To evaluate the caries experience, oral hygiene status and oral health knowledge of a group of visually impaired students. The study was conducted at one of the largest visually impaired children's schools among students aged between 7 and 16 years (n = 178) in Istanbul, Turkey. A 16-item questionnaire was asked in addition to a clinical tooth examination. The 16-item verbal questionnaire was developed to record the students' general health, impairment, the socioeconomic profile and education level of their parents, oral health knowledge, sources of information about oral health and oral hygiene habits. Oral hygiene was assessed according to Greene and Vermillion's Simplified Oral Hygiene Index (OHI-S). To measure the oral hygiene status, OHI-S index scores were recorded. Additionally, DMFT and dft indices were documented. Only 26.40% of children were caries free, and only 2.2% of students had good oral hygiene. A total of 3.3% of these students were mildly retarded and 2.8% of them had a developmental disability. Visually impaired children exhibited a fair-to-poor level of oral hygiene. Maintenance of oral hygiene remains the greatest challenge in the care of visually impaired children.

  16. Using Experience Language (LEA Variation) to Teach an Autistic-Like Child with a Visual Disorder to Read (and Write and Talk).

    ERIC Educational Resources Information Center

    Shepherd, Terry R.

    The author, a university professor, describes his experiences in teaching language to his autistic-like son who also has visual impairments. "Experience Language," an adaptation of Language Experience Approach (LEA) is described, and its contributions to the child's reading, writing, and talking are noted. Suggestions are made on the importance of…

  17. Using Correlative Properties of Neighboring Pixels to Enhance Contrast-to-Noise Ratio of Abnormal Hippocampus in Patients With Intractable Epilepsy and Mesial Temporal Sclerosis.

    PubMed

    Parsons, Matthew S; Sharma, Aseem; Hildebolt, Charles

    2018-06-12

    To test whether an image-processing algorithm can aid in visualization of mesial temporal sclerosis on magnetic resonance imaging by selectively increasing contrast-to-noise ratio (CNR) between abnormal hippocampus and normal brain. In this Institutional Review Board-approved and Health Insurance Portability and Accountability Act-compliant study, baseline coronal fluid-attenuated inversion recovery images of 18 adults (10 females, eight males; mean age 41.2 years) with proven mesial temporal sclerosis were processed using a custom algorithm to produce corresponding enhanced images. Average (Hmean) and maximum (Hmax) CNR for abnormal hippocampus were calculated relative to normal ipsilateral white matter. CNR values for normal gray matter (GM) were similarly calculated using ipsilateral cingulate gyrus as the internal control. To evaluate effect of image processing on visual conspicuity of hippocampal signal alteration, a neuroradiologist masked to the side of hippocampal abnormality rated signal intensity (SI) of hippocampi on baseline and enhanced images using a five-point scale (definitely abnormal to definitely normal). Differences in Hmean, Hmax, GM, and SI ratings for abnormal hippocampi on baseline and enhanced images were assessed for statistical significance. Both Hmean and Hmax were significantly higher in enhanced images as compared to baseline images (p < 0.0001 for both). There was no significant difference in the GM between baseline and enhanced images (p = 0.9375). SI ratings showed a more confident identification of abnormality on enhanced images (p = 0.0001). Image-processing resulted in increased CNR of abnormal hippocampus without affecting the CNR of normal gray matter. This selective increase in conspicuity of abnormal hippocampus was associated with more confident identification of hippocampal signal alteration. Copyright © 2018 Academic Radiology. Published by Elsevier Inc. All rights reserved.

  18. Object representations in visual memory: evidence from visual illusions.

    PubMed

    Ben-Shalom, Asaf; Ganel, Tzvi

    2012-07-26

    Human visual memory is considered to contain different levels of object representations. Representations in visual working memory (VWM) are thought to contain relatively elaborated information about object structure. Conversely, representations in iconic memory are thought to be more perceptual in nature. In four experiments, we tested the effects of two different categories of visual illusions on representations in VWM and in iconic memory. Unlike VWM that was affected by both types of illusions, iconic memory was immune to the effects of within-object contextual illusions and was affected only by illusions driven by between-objects contextual properties. These results show that iconic and visual working memory contain dissociable representations of object shape. These findings suggest that the global properties of the visual scene are processed prior to the processing of specific elements.

  19. Language identification from visual-only speech signals

    PubMed Central

    Ronquest, Rebecca E.; Levi, Susannah V.; Pisoni, David B.

    2010-01-01

    Our goal in the present study was to examine how observers identify English and Spanish from visual-only displays of speech. First, we replicated the recent findings of Soto-Faraco et al. (2007) with Spanish and English bilingual and monolingual observers using different languages and a different experimental paradigm (identification). We found that prior linguistic experience affected response bias but not sensitivity (Experiment 1). In two additional experiments, we investigated the visual cues that observers use to complete the language-identification task. The results of Experiment 2 indicate that some lexical information is available in the visual signal but that it is limited. Acoustic analyses confirmed that our Spanish and English stimuli differed acoustically with respect to linguistic rhythmic categories. In Experiment 3, we tested whether this rhythmic difference could be used by observers to identify the language when the visual stimuli is temporally reversed, thereby eliminating lexical information but retaining rhythmic differences. The participants performed above chance even in the backward condition, suggesting that the rhythmic differences between the two languages may aid language identification in visual-only speech signals. The results of Experiments 3A and 3B also confirm previous findings that increased stimulus length facilitates language identification. Taken together, the results of these three experiments replicate earlier findings and also show that prior linguistic experience, lexical information, rhythmic structure, and utterance length influence visual-only language identification. PMID:20675804

  20. Peripheral visual response time and visual display layout

    NASA Technical Reports Server (NTRS)

    Haines, R. F.

    1974-01-01

    Experiments were performed on a group of 42 subjects in a study of their peripheral visual response time to visual signals under positive acceleration, during prolonged bedrest, at passive 70 deg headup body lift, under exposures to high air temperatures and high luminance levels, and under normal stress-free laboratory conditions. Diagrams are plotted for mean response times to white, red, yellow, green, and blue stimuli under different conditions.

  1. Visual Impairment Screening at the Geriatric Frailty Clinic for Assessment of Frailty and Prevention of Disability at the Gérontopôle.

    PubMed

    Soler, V; Sourdet, S; Balardy, L; Abellan van Kan, G; Brechemier, D; Rougé-Bugat, M E; Tavassoli, N; Cassagne, M; Malecaze, F; Nourhashémi, F; Vellas, B

    2016-01-01

    To evaluate visual performance and factors associated with abnormal vision in patients screened for frailty at the Geriatric Frailty Clinic (GFC) for Assessment of Frailty and Prevention of Disability at Toulouse University Hospital. Retrospective, observational cross-sectional, single-centre study. Institutional practice. Patients were screened for frailty during a single-day hospital stay between October 2011 and October 2014 (n = 1648). Collected medical records included sociodemographic data (including living environment and educational level), anthropometric data, and clinical data. The general evaluation included the patient's functional status using the Activities of Daily Living (ADL) scale and the Instrumental Activity of Daily Living (IADL) scale, the Mini-Mental State Examination (MMSE) for cognition testing, and the Short Physical Performance Battery (SPPB) for physical performance. We also examined Body Mass Index (BMI), the Mini-Nutritional Assessment (MNA), and the Hearing Handicap Inventory for the Elderly Screening (HHIE-S) tool. The ophthalmologic evaluation included assessing visual acuity using the Snellen decimal chart for distant vision, and the Parinaud chart for near vision. Patients were divided into groups based on normal distant/near vision (NDV and NNV groups) and abnormal distant/near vision (ADV and ANV groups). Abnormal distant or near vision was defined as visual acuity inferior to 20/40 or superior to a Parinaud score of 2, in at least one eye. Associations with frailty-associated factors were evaluated in both groups. The mean age of the population was 82.6 ± 6.2 years. The gender distribution was 1,061 females (64.4%) and 587 males (35.6%). According to the Fried criteria, 619 patients (41.1%) were pre-frail and 771 (51.1%) were frail. Distant and near vision data were available for 1425 and 1426 patients, respectively. Distant vision was abnormal for 437 patients (30.7%). Near vision was abnormal for 199 patients (14%). Multiple

  2. Salient sounds activate human visual cortex automatically.

    PubMed

    McDonald, John J; Störmer, Viola S; Martinez, Antigona; Feng, Wenfeng; Hillyard, Steven A

    2013-05-22

    Sudden changes in the acoustic environment enhance perceptual processing of subsequent visual stimuli that appear in close spatial proximity. Little is known, however, about the neural mechanisms by which salient sounds affect visual processing. In particular, it is unclear whether such sounds automatically activate visual cortex. To shed light on this issue, this study examined event-related brain potentials (ERPs) that were triggered either by peripheral sounds that preceded task-relevant visual targets (Experiment 1) or were presented during purely auditory tasks (Experiments 2-4). In all experiments the sounds elicited a contralateral ERP over the occipital scalp that was localized to neural generators in extrastriate visual cortex of the ventral occipital lobe. The amplitude of this cross-modal ERP was predictive of perceptual judgments about the contrast of colocalized visual targets. These findings demonstrate that sudden, intrusive sounds reflexively activate human visual cortex in a spatially specific manner, even during purely auditory tasks when the sounds are not relevant to the ongoing task.

  3. Application Of Empirical Phase Diagrams For Multidimensional Data Visualization Of High Throughput Microbatch Crystallization Experiments.

    PubMed

    Klijn, Marieke E; Hubbuch, Jürgen

    2018-04-27

    Protein phase diagrams are a tool to investigate cause and consequence of solution conditions on protein phase behavior. The effects are scored according to aggregation morphologies such as crystals or amorphous precipitates. Solution conditions affect morphological features, such as crystal size, as well as kinetic features, such as crystal growth time. Common used data visualization techniques include individual line graphs or symbols-based phase diagrams. These techniques have limitations in terms of handling large datasets, comprehensiveness or completeness. To eliminate these limitations, morphological and kinetic features obtained from crystallization images generated with high throughput microbatch experiments have been visualized with radar charts in combination with the empirical phase diagram (EPD) method. Morphological features (crystal size, shape, and number, as well as precipitate size) and kinetic features (crystal and precipitate onset and growth time) are extracted for 768 solutions with varying chicken egg white lysozyme concentration, salt type, ionic strength and pH. Image-based aggregation morphology and kinetic features were compiled into a single and easily interpretable figure, thereby showing that the EPD method can support high throughput crystallization experiments in its data amount as well as its data complexity. Copyright © 2018. Published by Elsevier Inc.

  4. Postdictive modulation of visual orientation.

    PubMed

    Kawabe, Takahiro

    2012-01-01

    The present study investigated how visual orientation is modulated by subsequent orientation inputs. Observers were presented a near-vertical Gabor patch as a target, followed by a left- or right-tilted second Gabor patch as a distracter in the spatial vicinity of the target. The task of the observers was to judge whether the target was right- or left-tilted (Experiment 1) or whether the target was vertical or not (Supplementary experiment). The judgment was biased toward the orientation of the distracter (the postdictive modulation of visual orientation). The judgment bias peaked when the target and distracter were temporally separated by 100 ms, indicating a specific temporal mechanism for this phenomenon. However, when the visibility of the distracter was reduced via backward masking, the judgment bias disappeared. On the other hand, the low-visibility distracter could still cause a simultaneous orientation contrast, indicating that the distracter orientation is still processed in the visual system (Experiment 2). Our results suggest that the postdictive modulation of visual orientation stems from spatiotemporal integration of visual orientation on the basis of a slow feature matching process.

  5. Creativity, visualization abilities, and visual cognitive style.

    PubMed

    Kozhevnikov, Maria; Kozhevnikov, Michael; Yu, Chen Jiao; Blazhenkova, Olesya

    2013-06-01

    Despite the recent evidence for a multi-component nature of both visual imagery and creativity, there have been no systematic studies on how the different dimensions of creativity and imagery might interrelate. The main goal of this study was to investigate the relationship between different dimensions of creativity (artistic and scientific) and dimensions of visualization abilities and styles (object and spatial). In addition, we compared the contributions of object and spatial visualization abilities versus corresponding styles to scientific and artistic dimensions of creativity. Twenty-four undergraduate students (12 females) were recruited for the first study, and 75 additional participants (36 females) were recruited for an additional experiment. Participants were administered a number of object and spatial visualization abilities and style assessments as well as a number of artistic and scientific creativity tests. The results show that object visualization relates to artistic creativity and spatial visualization relates to scientific creativity, while both are distinct from verbal creativity. Furthermore, our findings demonstrate that style predicts corresponding dimension of creativity even after removing shared variance between style and visualization ability. The results suggest that styles might be a more ecologically valid construct in predicting real-life creative behaviour, such as performance in different professional domains. © 2013 The British Psychological Society.

  6. Cervical cancer prevention knowledge and abnormal Pap test experiences among women living with HIV/AIDS

    PubMed Central

    Wigfall, Lisa T.; Bynum, Shalanda A; Brandt, Heather M.; Friedman, Daniela B.; Bond, Sharon M.; Lazenby, Gweneth B.; Richter, Donna L.; Glover, Saundra H.; Hébert, James R.

    2014-01-01

    Background Cervical cancer prevention knowledge deficits persist among women living with HIV/AIDS (WLHA) despite increased risk of developing cervical dysplasia/cancer. We examined associations between WLHA’s cervical cancer prevention knowledge and abnormal Pap test history. Methods We recruited 145 urban and rural WLHA from Ryan White-funded clinics and AIDS service organizations located in the southeastern United States between March 2011 and April 2012. For this analysis, women who reported a history of cervical cancer (n=3) or had a complete hysterectomy (n=14), and observations with missing data (n=22) were excluded. Stata/IC 13 was used to perform cross-tabulations and chi-squared tests. Results Our sample included 106 predominantly non-Hispanic Black (92%) WLHA. Mean age was 46.3±10.9 years. Half (50%) had ≤ high school education. One-third (37%) had low health literacy. The majority (83%) had a Pap test <1 year ago and 84% knew that WLHA should have a Pap test every year, once two tests are normal. Many (68%) have had an abnormal Pap test. Abnormal Pap test follow-up care knowledge varied. While 86% knew follow-up care could include a repeat Pap test, only 56% knew this could also include an HPV test. Significantly more women who had an abnormal Pap test knew follow-up care could include a biopsy (p=0.001). Conclusions For WLHA to make informed/shared decisions about their cervical health, they need to be knowledgeable about cervical cancer care options across the cancer control continuum. Providing WLHA with prevention knowledge beyond screening recommendations seems warranted given their increased risk of developing cervical dysplasia/neoplasia. PMID:24928481

  7. Subjective evaluation of two stereoscopic imaging systems exploiting visual attention to improve 3D quality of experience

    NASA Astrophysics Data System (ADS)

    Hanhart, Philippe; Ebrahimi, Touradj

    2014-03-01

    Crosstalk and vergence-accommodation rivalry negatively impact the quality of experience (QoE) provided by stereoscopic displays. However, exploiting visual attention and adapting the 3D rendering process on the fly can reduce these drawbacks. In this paper, we propose and evaluate two different approaches that exploit visual attention to improve 3D QoE on stereoscopic displays: an offline system, which uses a saliency map to predict gaze position, and an online system, which uses a remote eye tracking system to measure real time gaze positions. The gaze points were used in conjunction with the disparity map to extract the disparity of the object-of-interest. Horizontal image translation was performed to bring the fixated object on the screen plane. The user preference between standard 3D mode and the two proposed systems was evaluated through a subjective evaluation. Results show that exploiting visual attention significantly improves image quality and visual comfort, with a slight advantage for real time gaze determination. Depth quality is also improved, but the difference is not significant.

  8. Outcome of chromosomally abnormal pregnancies in Lebanon: obstetricians' roles during and after prenatal diagnosis.

    PubMed

    Eldahdah, Lama T; Ormond, Kelly E; Nassar, Anwar H; Khalil, Tayma; Zahed, Laila F

    2007-06-01

    To better understand obstetrician experiences in Lebanon when disclosing abnormal amniocentesis results. Structured interviews with 38 obstetricians identified as caregivers from the American University of Beirut Medical Center Cytogenetics Laboratory database of patients with abnormal amniocentesis results between 1999 and 2005. Obstetricians were primarily male, Christian, and with an average of 14 years of experience. They reported doing most pre-amniocentesis counseling, including discussion of risk for common autosomal aneuplodies (95%), and procedure-related risk (95%). Obstetricians reported that 80% of patients at risk for aneuploidy underwent amniocentesis. The study population reported on 143 abnormal test results (124 autosomal abnormalities). When disclosing results, obstetricians reportedly discussed primarily physical and cognitive features of the diagnosis. They varied in levels of directiveness and comfort in providing information. Our records showed that 59% of pregnancies with sex chromosome abnormalities were terminated compared to 90% of those with autosomal aneuploidies; various reasons were proposed by obstetricians. This study is among the few to assess prenatal diagnosis practices in the Middle East, with a focus on the role of the obstetrician. Given the influence of culture and social norms on prenatal decision-making, it remains important to understand the various impacts on clinical practice in many nations. (c) 2007 John Wiley & Sons, Ltd.

  9. Hallucinatory experiences in visually impaired individuals: Charles Bonnet syndrome - implications for research and clinical practice.

    PubMed

    Jurišić, Darija; Sesar, Irena; Ćavar, Ivan; Sesar, Antonio; Živković, Maja; Ćurković, Marko

    2018-06-01

    Charles Bonnet syndrome (CBS) refers to visual hallucinations that occur in individuals with preserved cognitive functions associated with visual impairment. This article reviews occurence of visual hallucinations in subjects with CBS by journals published in English in the Pubmed database in the period 1992-2018. Criteria for selection of appropriate papers were sufficient information and perspicuous view on pathogenesis, epidemiology, clinical presentation and treatment possibilities of CBS. Most commonly, visual hallucinations in patients with CBS are complex, repetitive and stereotyped. Such individuals have preserved insight that those percepts are not real, and there is an absence of secondary explanatory delusions and hallucinations within other modalities. Seeing as the aforementioned percepts do not share all the characteristics of hallucinations, it remains unresolved how they should be referred to. Terms as release hallucinations, one that is reflecting its underlying pathogenesis, or confabulatory hallucinatory experiences have been proposed. Moreover, CBS has also been referred to as phantom vision syndrome and may occur in any ophthalmological disease. It is not particularly connected with loss of function along any level of the visual pathway. Although this syndrome is mostly associated with age-related macular degeneration, glaucoma and cataract, it could be related to almost any other ophthalmological conditions. The incidence of CBS alongside with mostly other ocular pathology is rising as population is ageing. Nonetheless, CBS remains commonly underreported, under recognized and/or misrecognized. Albeit the treatment recommendations and guidelines are not yet fully established, it is important to raise awareness of this specific and distinct condition, which inevitably implicates many differential diagnostic deliberations.

  10. Symptoms related to glaucomatous visual field abnormalities among male Japanese workers in a population-based setting.

    PubMed

    Tatemichi, Masayuki; Nakano, Tadashi; Hayashi, Takeshi; Tanaka, Katsutoshi; Hiro, Hisanori; Miyamoto, Toshiaki; Aratake, Miho; Nishinoue, Norihide; Yamazaki, Akira; Nakadate, Toshio; Sugita, Minoru

    2012-09-01

    To identify symptoms potentially related to glaucomatous visual field abnormalities (VFAs) in a population-based setting, and to assess the applicability of using these symptoms to identify persons at risk of developing glaucoma. In this study, 10,214 Japanese male general workers (mean age, 45.3±8.8 years) filled out a self-administered questionnaire and underwent frequency doubling technology (FDT) perimetry testing. The questionnaire inquired about whether the participant was suffering from any of nine symptoms, with scores for each response graded on a four-item Likert scale: 0 (none), 1 (rarely), 2 (sometimes), and 3 (always). Results from the questionnaire were compared among three groups: participants without any VFAs (9767), participants with VFAs as determined by the FDT test (FDT-VFA; 447), and 227 participants (of the 447 FDT-VFA participants) with glaucomatous VFAs who were newly diagnosed by ophthalmologic examinations. The mean summed scores for the total items were significantly (p<0.01) higher in FDT- and glaucomatous VFA groups than in normal subjects. In particular, responses citing the symptoms 'feeling of something in the front of the eye' and 'feeling of hardness to see in dark places' were significantly (p<0.05) more frequent in subjects with FDT- and glaucomatous VFAs than among normal participants. However, the respective areas under the receiver operating characteristic curve of summed scores for the nine total items and for the two items which showed significant differences for the glaucoma groups were 0.57 (95% confidence interval=0.53-0.60) and 0.58 (95% confidence interval=0.54-0.61). Although the symptoms 'feeling of hardness to see in dark places' and 'feeling of something in the front of the eye' could be associated with glaucomatous VFA in a population-based setting, inquiring about symptoms is of little aid in identifying subjects with glaucomatous VFA as a strategy for public health. © 2010 The Authors. Journal compilation

  11. AODA Training Experiences of Blindness and Visual Impairment Professionals

    ERIC Educational Resources Information Center

    Davis, S. J.; Koch, D. Shane; McKee, Marissa F.; Nelipovich, Michael

    2009-01-01

    Co-existing alcohol and other drug abuse (AODA) and blindness or visually impairment may complicate the delivery of rehabilitation services. Professionals working with individuals who are blind or visually impaired need to be aware of unique issues facing those with co-existing disabilities. This study sought to examine the AODA training needs,…

  12. Abnormal brain activation in neurofibromatosis type 1: a link between visual processing and the default mode network.

    PubMed

    Violante, Inês R; Ribeiro, Maria J; Cunha, Gil; Bernardino, Inês; Duarte, João V; Ramos, Fabiana; Saraiva, Jorge; Silva, Eduardo; Castelo-Branco, Miguel

    2012-01-01

    Neurofibromatosis type 1 (NF1) is one of the most common single gene disorders affecting the human nervous system with a high incidence of cognitive deficits, particularly visuospatial. Nevertheless, neurophysiological alterations in low-level visual processing that could be relevant to explain the cognitive phenotype are poorly understood. Here we used functional magnetic resonance imaging (fMRI) to study early cortical visual pathways in children and adults with NF1. We employed two distinct stimulus types differing in contrast and spatial and temporal frequencies to evoke relatively different activation of the magnocellular (M) and parvocellular (P) pathways. Hemodynamic responses were investigated in retinotopically-defined regions V1, V2 and V3 and then over the acquired cortical volume. Relative to matched control subjects, patients with NF1 showed deficient activation of the low-level visual cortex to both stimulus types. Importantly, this finding was observed for children and adults with NF1, indicating that low-level visual processing deficits do not ameliorate with age. Moreover, only during M-biased stimulation patients with NF1 failed to deactivate or even activated anterior and posterior midline regions of the default mode network. The observation that the magnocellular visual pathway is impaired in NF1 in early visual processing and is specifically associated with a deficient deactivation of the default mode network may provide a neural explanation for high-order cognitive deficits present in NF1, particularly visuospatial and attentional. A link between magnocellular and default mode network processing may generalize to neuropsychiatric disorders where such deficits have been separately identified.

  13. Visual and Non-Visual Contributions to the Perception of Object Motion during Self-Motion

    PubMed Central

    Fajen, Brett R.; Matthis, Jonathan S.

    2013-01-01

    Many locomotor tasks involve interactions with moving objects. When observer (i.e., self-)motion is accompanied by object motion, the optic flow field includes a component due to self-motion and a component due to object motion. For moving observers to perceive the movement of other objects relative to the stationary environment, the visual system could recover the object-motion component – that is, it could factor out the influence of self-motion. In principle, this could be achieved using visual self-motion information, non-visual self-motion information, or a combination of both. In this study, we report evidence that visual information about the speed (Experiment 1) and direction (Experiment 2) of self-motion plays a role in recovering the object-motion component even when non-visual self-motion information is also available. However, the magnitude of the effect was less than one would expect if subjects relied entirely on visual self-motion information. Taken together with previous studies, we conclude that when self-motion is real and actively generated, both visual and non-visual self-motion information contribute to the perception of object motion. We also consider the possible role of this process in visually guided interception and avoidance of moving objects. PMID:23408983

  14. Optimization of Visual Information Presentation for Visual Prosthesis.

    PubMed

    Guo, Fei; Yang, Yuan; Gao, Yong

    2018-01-01

    Visual prosthesis applying electrical stimulation to restore visual function for the blind has promising prospects. However, due to the low resolution, limited visual field, and the low dynamic range of the visual perception, huge loss of information occurred when presenting daily scenes. The ability of object recognition in real-life scenarios is severely restricted for prosthetic users. To overcome the limitations, optimizing the visual information in the simulated prosthetic vision has been the focus of research. This paper proposes two image processing strategies based on a salient object detection technique. The two processing strategies enable the prosthetic implants to focus on the object of interest and suppress the background clutter. Psychophysical experiments show that techniques such as foreground zooming with background clutter removal and foreground edge detection with background reduction have positive impacts on the task of object recognition in simulated prosthetic vision. By using edge detection and zooming technique, the two processing strategies significantly improve the recognition accuracy of objects. We can conclude that the visual prosthesis using our proposed strategy can assist the blind to improve their ability to recognize objects. The results will provide effective solutions for the further development of visual prosthesis.

  15. Optimization of Visual Information Presentation for Visual Prosthesis

    PubMed Central

    Gao, Yong

    2018-01-01

    Visual prosthesis applying electrical stimulation to restore visual function for the blind has promising prospects. However, due to the low resolution, limited visual field, and the low dynamic range of the visual perception, huge loss of information occurred when presenting daily scenes. The ability of object recognition in real-life scenarios is severely restricted for prosthetic users. To overcome the limitations, optimizing the visual information in the simulated prosthetic vision has been the focus of research. This paper proposes two image processing strategies based on a salient object detection technique. The two processing strategies enable the prosthetic implants to focus on the object of interest and suppress the background clutter. Psychophysical experiments show that techniques such as foreground zooming with background clutter removal and foreground edge detection with background reduction have positive impacts on the task of object recognition in simulated prosthetic vision. By using edge detection and zooming technique, the two processing strategies significantly improve the recognition accuracy of objects. We can conclude that the visual prosthesis using our proposed strategy can assist the blind to improve their ability to recognize objects. The results will provide effective solutions for the further development of visual prosthesis. PMID:29731769

  16. Why are there eccentricity effects in visual search? Visual and attentional hypotheses.

    PubMed

    Wolfe, J M; O'Neill, P; Bennett, S C

    1998-01-01

    In standard visual search experiments, observers search for a target item among distracting items. The locations of target items are generally random within the display and ignored as a factor in data analysis. Previous work has shown that targets presented near fixation are, in fact, found more efficiently than are targets presented at more peripheral locations. This paper proposes that the primary cause of this "eccentricity effect" (Carrasco, Evert, Chang, & Katz, 1995) is an attentional bias that allocates attention preferentially to central items. The first four experiments dealt with the possibility that visual, and not attentional, factors underlie the eccentricity effect. They showed that the eccentricity effect cannot be accounted for by the peripheral reduction in visual sensitivity, peripheral crowding, or cortical magnification. Experiment 5 tested the attention allocation model and also showed that RT x set size effects can be independent of eccentricity effects. Experiment 6 showed that the effective set size in a search task depends, in part, on the eccentricity of the target because observers search from fixation outward.

  17. Drivers' Visual Search Behavior Toward Vulnerable Road Users at Junctions as a Function of Cycling Experience.

    PubMed

    Robbins, Chloe Jade; Chapman, Peter

    2018-06-01

    The current study investigated the behavior and visual attention of two groups of drivers with differing pedal cycling experience (pedal cyclists and nonpedal cyclists) towards vulnerable road users at junctions in a driving simulator. Pedal cyclists and motorcyclists are involved in a disproportionate number of crashes given the distance they travel, with a high proportion of these crashes occurring at junctions. Many studies have found that car drivers who also hold a motorcycle license have increased awareness towards motorcycles. The task involved approaching a T-junction and turning right when it was deemed to be safe. In Study 1, the junction was controlled by a give way sign, and in Study 2, the junction was controlled by a stop sign. Each T-junction contained a target vehicle (car, motorcycle, or pedal cycle), approaching from a near, medium, or far distance from the junction. Participants did not look at pedal cycles approaching from a far distance for as long as they looked at approaching motorcycles and cars, despite all vehicles travelling at identical speeds. No differences were found between pedal cyclists and nonpedal cyclists on any visual attention measures, indicating that pedal cycling experience was not associated with differences in drivers' attention toward pedal cycles. Findings have implications for road safety, demonstrating subtle differences in drivers' everyday visual attention toward differing vehicle types. This research has the potential to inform the development of in-car technical assistive systems, improving the safety of vulnerable road users at junctions.

  18. Visual observing reports

    NASA Astrophysics Data System (ADS)

    Roggemans, Paul

    2016-01-01

    In this overview we summarize reports published by visual observers shortly after the field work has been done and first impressions and memories of the real meteor observing experiences are fresh in mind. March-April being silent months meteor wise and the weather circumstances in 2016 having been rather unfavorable almost no visual observing efforts have been reported. Long term visual observer, Koen Miskotte could observe in this rather poorly known period and reported his data in MeteorNews.org. The Eta Aquariids 2016 provided a surprising nice display well covered by fellow visual observer Paul Jones in Florida.

  19. Abnormal pressure in hydrocarbon environments

    USGS Publications Warehouse

    Law, B.E.; Spencer, C.W.

    1998-01-01

    Abnormal pressures, pressures above or below hydrostatic pressures, occur on all continents in a wide range of geological conditions. According to a survey of published literature on abnormal pressures, compaction disequilibrium and hydrocarbon generation are the two most commonly cited causes of abnormally high pressure in petroleum provinces. In young (Tertiary) deltaic sequences, compaction disequilibrium is the dominant cause of abnormal pressure. In older (pre-Tertiary) lithified rocks, hydrocarbon generation, aquathermal expansion, and tectonics are most often cited as the causes of abnormal pressure. The association of abnormal pressures with hydrocarbon accumulations is statistically significant. Within abnormally pressured reservoirs, empirical evidence indicates that the bulk of economically recoverable oil and gas occurs in reservoirs with pressure gradients less than 0.75 psi/ft (17.4 kPa/m) and there is very little production potential from reservoirs that exceed 0.85 psi/ft (19.6 kPa/m). Abnormally pressured rocks are also commonly associated with unconventional gas accumulations where the pressuring phase is gas of either a thermal or microbial origin. In underpressured, thermally mature rocks, the affected reservoirs have most often experienced a significant cooling history and probably evolved from an originally overpressured system.

  20. Splitting attention across the two visual fields in visual short-term memory.

    PubMed

    Delvenne, Jean-Francois; Holt, Jessica L

    2012-02-01

    Humans have the ability to attentionally select the most relevant visual information from their extrapersonal world and to retain it in a temporary buffer, known as visual short-term memory (VSTM). Research suggests that at least two non-contiguous items can be selected simultaneously when they are distributed across the two visual hemifields. In two experiments, we show that attention can also be split between the left and right sides of internal representations held in VSTM. Participants were asked to remember several colors, while cues presented during the delay instructed them to orient their attention to a subset of memorized colors. Experiment 1 revealed that orienting attention to one or two colors strengthened equally participants' memory for those colors, but only when they were from separate hemifields. Experiment 2 showed that in the absence of attentional cues the distribution of the items in the visual field per se had no effect on memory. These findings strongly suggest the existence of independent attentional resources in the two hemifields for selecting and/or consolidating information in VSTM. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Spent fuel behavior under abnormal thermal transients during dry storage

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stahl, D.; Landow, M.P.; Burian, R.J.

    1986-01-01

    This study was performed to determine the effects of abnormally high temperatures on spent fuel behavior. Prior to testing, calculations using the CIRFI3 code were used to determine the steady-state fuel and cask component temperatures. The TRUMP code was used to determine transient heating rates under postulated abnormal events during which convection cooling of the cask surfaces was obstructed by a debris bed covering the cask. The peak rate of temperature rise during the first 6 h was calculated to be about 15/sup 0/C/h, followed by a rate of about 1/sup 0/C/h. A Turkey Point spent fuel rod segment wasmore » heated to approx. 800/sup 0/C. The segment deformed uniformly with an average strain of 17% at failure and a local strain of 60%. Pretest characterization of the spent fuel consisted of visual examination, profilometry, eddy-current examination, gamma scanning, fission gas collection, void volume measurement, fission gas analysis, hydrogen analysis of the cladding, burnup analysis, cladding metallography, and fuel ceramography. Post-test characterization showed that the failure was a pinhole cladding breach. The results of the tests showed that spent fuel temperatures in excess of 700/sup 0/C are required to produce a cladding breach in fuel rods pressurized to 500 psing (3.45 MPa) under postulated abnormal thermal transient cask conditions. The pinhole cladding breach that developed would be too small to compromise the confinement of spent fuel particles during an abnormal event or after normal cooling conditions are restored. This behavior is similar to that found in other slow ramp tests with irradiated and nonirradiated rod sections and nonirradiated whole rods under conditions that bracketed postulated abnormal heating rates. This similarity is attributed to annealing of the irradiation-strengthened Zircaloy cladding during heating. In both cases, the failure was a benign, ductile pinhole rupture.« less

  2. Visual Function in Carriers of X-linked Retinitis Pigmentosa

    PubMed Central

    Comander, Jason; Weigel-DiFranco, Carol; Sandberg, Michael A.; Berson, Eliot L.

    2015-01-01

    Purpose To determine the frequency and severity of visual function loss in female carriers of X-linked retinitis pigmentosa (XLRP). Design Case series. Participants XLRP carriers with cross-sectional data (n = 242) and longitudinal data (n = 34, median follow-up: 16 years, follow-up range: 3–37 years). Half of the carriers were from RPGR- or RP2-genotyped families. Methods Retrospective medical records review. Main Outcome Measures Visual acuities, visual field areas, final dark adaptation thresholds, and full-field ERGs to 0.5 Hz and 30 Hz flashes. Results In genotyped families, 40% of carriers showed a baseline abnormality on at least one of the three psychophysical tests. There was a wide range of function among carriers; for example 3 of 121 (2%) of genotyped carriers were legally blind due to poor visual acuity, some as young as 35 years of age. Visual fields were less affected than visual acuity. In all carriers, the average ERG amplitude to 30 Hz flashes was about 50% of normal, and the average exponential rate of amplitude loss over time was half that of XLRP males (3.7%/year vs 7.4%/year, respectively). Among obligate carriers with affected fathers and/or sons, 53 of 55 (96%) had abnormal baseline ERGs. Some carriers who initially had completely normal fundi in both eyes went on to develop moderately decreased vision, though not legal blindness. Among carriers with RPGR mutations, those with mutations in ORF15, compared to those in exons 1–14, had worse final dark adaptation thresholds and lower 0.5 Hz and 30 Hz ERG amplitudes. Conclusions Most carriers of XLRP had mildly or moderately reduced visual function but rarely became legally blind. In most cases, obligate carriers could be identified by ERG testing. Carriers of RPGR ORF15 mutations tended to have worse visual function than carriers of RPGR exon 1–14 mutations. Since XLRP carrier ERG amplitudes and decay rates over time were on average half of those of affected males, these observations were

  3. Abnormal Circulation Changes in the Winter Stratosphere, Detected Through Variations of D Region Ionospheric Absorption

    NASA Technical Reports Server (NTRS)

    Delamorena, B. A.

    1984-01-01

    A method to detect stratospheric warmings using ionospheric absorption records obtained by an Absorption Meter (method A3) is introduced. The activity of the stratospheric circulation and the D region ionospheric absorption as well as other atmospheric parameters during the winter anomaly experience an abnormal variation. A simultaneity was found in the beginning of abnormal variation in the mentioned parameters, using the absorption records for detecting the initiation of the stratospheric warming. Results of this scientific experience of forecasting in the El Arenosillo Range, are presented.

  4. Causes of severe visual impairment and blindness in children attending schools for the visually handicapped in the Czech Republic.

    PubMed

    Kocur, I; Kuchynka, P; Rodný, S; Baráková, D; Schwartz, E C

    2001-10-01

    To describe the causes of severe visual impairment and blindness in children in schools for the visually handicapped in the Czech Republic in 1998. Pupils attending all 10 primary schools for the visually handicapped were examined. A modified WHO/PBL eye examination record for children with blindness and low vision was used. 229 children (146 males and 83 females) aged 6-15 years were included in the study: 47 children had severe visual impairment (20.5%) (visual acuity in their better eye less than 6/60), and 159 were blind (69.5%) (visual acuity in their better eye less than 3/60). Anatomically, the most affected parts of the eye were the retina (124, 54.2%), optic nerve (35, 15.3%), whole globe (25, 10.9%), lens (20, 8.7%), and uvea (12, 5.2%). Aetiologically (timing of insult leading to visual loss), the major cause of visual impairment was retinopathy of prematurity (ROP) (96, 41.9 %), followed by abnormalities of unknown timing of insult (97, 42.4%), and hereditary disease (21, 9.2%). In 90 children (40%), additional disabilities were present: mental disability (36, 16%), physical handicap (16, 7%), and/or a combination of both (19, 8%). It was estimated that 127 children (56%) suffer from visual impairment caused by potentially preventable and/or treatable conditions (for example, ROP, cataract, glaucoma). Establishing a study group for comprehensive evaluation of causes of visual handicap in children in the Czech Republic, as well as for detailed analysis of present practice of screening for ROP was recommended.

  5. Top-Down and Bottom-Up Visual Information Processing of Non-Social Stimuli in High-Functioning Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Maekawa, Toshihiko; Tobimatsu, Shozo; Inada, Naoko; Oribe, Naoya; Onitsuka, Toshiaki; Kanba, Shigenobu; Kamio, Yoko

    2011-01-01

    Individuals with high-functioning autism spectrum disorder (HF-ASD) often show superior performance in simple visual tasks, despite difficulties in the perception of socially important information such as facial expression. The neural basis of visual perception abnormalities associated with HF-ASD is currently unclear. We sought to elucidate the…

  6. Varenicline and Abnormal Sleep Related Events

    PubMed Central

    Savage, Ruth L.; Zekarias, Alem; Caduff-Janosa, Pia

    2015-01-01

    Study Objectives: To assess adverse drug reaction reports of “abnormal sleep related events” associated with varenicline, a partial agonist to the α4β2 subtype of nicotinic acetylcholine receptors on neurones, indicated for smoking cessation. Design: Twenty-seven reports of “abnormal sleep related events” often associated with abnormal dreams, nightmares, or somnambulism, which are known to be associated with varenicline use, were identified in the World Health Organisation (WHO) Global Individual Case Safety Reports Database. Original anonymous reports were obtained from the four national pharmacovigilance centers that submitted these reports and assessed for reaction description and causality. Measurements and Results: These 27 reports include 10 of aggressive activity occurring during sleep and seven of other sleep related harmful or potentially harmful activities, such as apparently deliberate self-harm, moving a child or a car, or lighting a stove or a cigarette. Assessment of these 17 reports of aggression or other actual or potential harm showed that nine patients recovered or were recovering on varenicline withdrawal and there were no consistent alternative explanations. Thirteen patients experienced single events, and two had multiple events. Frequency was not stated for the remaining two patients. Conclusions: The descriptions of the reports of aggression during sleep with violent dreaming are similar to those of rapid eye movement sleep behavior disorder and also nonrapid eye movement (NREM) sleep parasomnias in some adults. Patients who experience somnambulism or dreams of a violent nature while taking varenicline should be advised to consult their health providers. Consideration should be given to clarifying the term sleep disorders in varenicline product information and including sleep related harmful and potentially harmful events. Citation: Savage RL, Zekarias A, Caduff-Janosa P. Varenicline and abnormal sleep related events. SLEEP 2015

  7. The Automatic Recognition of the Abnormal Sky-subtraction Spectra Based on Hadoop

    NASA Astrophysics Data System (ADS)

    An, An; Pan, Jingchang

    2017-10-01

    The skylines, superimposing on the target spectrum as a main noise, If the spectrum still contains a large number of high strength skylight residuals after sky-subtraction processing, it will not be conducive to the follow-up analysis of the target spectrum. At the same time, the LAMOST can observe a quantity of spectroscopic data in every night. We need an efficient platform to proceed the recognition of the larger numbers of abnormal sky-subtraction spectra quickly. Hadoop, as a distributed parallel data computing platform, can deal with large amounts of data effectively. In this paper, we conduct the continuum normalization firstly and then a simple and effective method will be presented to automatic recognize the abnormal sky-subtraction spectra based on Hadoop platform. Obtain through the experiment, the Hadoop platform can implement the recognition with more speed and efficiency, and the simple method can recognize the abnormal sky-subtraction spectra and find the abnormal skyline positions of different residual strength effectively, can be applied to the automatic detection of abnormal sky-subtraction of large number of spectra.

  8. Abnormalities in early visual processes are linked to hypersociability and atypical evaluation of facial trustworthiness: An ERP study with Williams syndrome.

    PubMed

    Shore, Danielle M; Ng, Rowena; Bellugi, Ursula; Mills, Debra L

    2017-10-01

    Accurate assessment of trustworthiness is fundamental to successful and adaptive social behavior. Initially, people assess trustworthiness from facial appearance alone. These assessments then inform critical approach or avoid decisions. Individuals with Williams syndrome (WS) exhibit a heightened social drive, especially toward strangers. This study investigated the temporal dynamics of facial trustworthiness evaluation in neurotypic adults (TD) and individuals with WS. We examined whether differences in neural activity during trustworthiness evaluation may explain increased approach motivation in WS compared to TD individuals. Event-related potentials were recorded while participants appraised faces previously rated as trustworthy or untrustworthy. TD participants showed increased sensitivity to untrustworthy faces within the first 65-90 ms, indexed by the negative-going rise of the P1 onset (oP1). The amplitude of the oP1 difference to untrustworthy minus trustworthy faces was correlated with lower approachability scores. In contrast, participants with WS showed increased N170 amplitudes to trustworthy faces. The N170 difference to low-high-trust faces was correlated with low approachability in TD and high approachability in WS. The findings suggest that hypersociability associated with WS may arise from abnormalities in the timing and organization of early visual brain activity during trustworthiness evaluation. More generally, the study provides support for the hypothesis that impairments in low-level perceptual processes can have a cascading effect on social cognition.

  9. Cluster structure in the correlation coefficient matrix can be characterized by abnormal eigenvalues

    NASA Astrophysics Data System (ADS)

    Nie, Chun-Xiao

    2018-02-01

    In a large number of previous studies, the researchers found that some of the eigenvalues of the financial correlation matrix were greater than the predicted values of the random matrix theory (RMT). Here, we call these eigenvalues as abnormal eigenvalues. In order to reveal the hidden meaning of these abnormal eigenvalues, we study the toy model with cluster structure and find that these eigenvalues are related to the cluster structure of the correlation coefficient matrix. In this paper, model-based experiments show that in most cases, the number of abnormal eigenvalues of the correlation matrix is equal to the number of clusters. In addition, empirical studies show that the sum of the abnormal eigenvalues is related to the clarity of the cluster structure and is negatively correlated with the correlation dimension.

  10. The predictive mind and the experience of visual art work

    PubMed Central

    Kesner, Ladislav

    2014-01-01

    Among the main challenges of the predictive brain/mind concept is how to link prediction at the neural level to prediction at the cognitive-psychological level and finding conceptually robust and empirically verifiable ways to harness this theoretical framework toward explaining higher-order mental and cognitive phenomena, including the subjective experience of aesthetic and symbolic forms. Building on the tentative prediction error account of visual art, this article extends the application of the predictive coding framework to the visual arts. It does so by linking this theoretical discussion to a subjective, phenomenological account of how a work of art is experienced. In order to engage more deeply with a work of art, viewers must be able to tune or adapt their prediction mechanism to recognize art as a specific class of objects whose ontological nature defies predictability, and they must be able to sustain a productive flow of predictions from low-level sensory, recognitional to abstract semantic, conceptual, and affective inferences. The affective component of the process of predictive error optimization that occurs when a viewer enters into dialog with a painting is constituted both by activating the affective affordances within the image and by the affective consequences of prediction error minimization itself. The predictive coding framework also has implications for the problem of the culturality of vision. A person’s mindset, which determines what top–down expectations and predictions are generated, is co-constituted by culture-relative skills and knowledge, which form hyperpriors that operate in the perception of art. PMID:25566111

  11. The predictive mind and the experience of visual art work.

    PubMed

    Kesner, Ladislav

    2014-01-01

    Among the main challenges of the predictive brain/mind concept is how to link prediction at the neural level to prediction at the cognitive-psychological level and finding conceptually robust and empirically verifiable ways to harness this theoretical framework toward explaining higher-order mental and cognitive phenomena, including the subjective experience of aesthetic and symbolic forms. Building on the tentative prediction error account of visual art, this article extends the application of the predictive coding framework to the visual arts. It does so by linking this theoretical discussion to a subjective, phenomenological account of how a work of art is experienced. In order to engage more deeply with a work of art, viewers must be able to tune or adapt their prediction mechanism to recognize art as a specific class of objects whose ontological nature defies predictability, and they must be able to sustain a productive flow of predictions from low-level sensory, recognitional to abstract semantic, conceptual, and affective inferences. The affective component of the process of predictive error optimization that occurs when a viewer enters into dialog with a painting is constituted both by activating the affective affordances within the image and by the affective consequences of prediction error minimization itself. The predictive coding framework also has implications for the problem of the culturality of vision. A person's mindset, which determines what top-down expectations and predictions are generated, is co-constituted by culture-relative skills and knowledge, which form hyperpriors that operate in the perception of art.

  12. Salient sounds activate human visual cortex automatically

    PubMed Central

    McDonald, John J.; Störmer, Viola S.; Martinez, Antigona; Feng, Wenfeng; Hillyard, Steven A.

    2013-01-01

    Sudden changes in the acoustic environment enhance perceptual processing of subsequent visual stimuli that appear in close spatial proximity. Little is known, however, about the neural mechanisms by which salient sounds affect visual processing. In particular, it is unclear whether such sounds automatically activate visual cortex. To shed light on this issue, the present study examined event-related brain potentials (ERPs) that were triggered either by peripheral sounds that preceded task-relevant visual targets (Experiment 1) or were presented during purely auditory tasks (Experiments 2, 3, and 4). In all experiments the sounds elicited a contralateral ERP over the occipital scalp that was localized to neural generators in extrastriate visual cortex of the ventral occipital lobe. The amplitude of this cross-modal ERP was predictive of perceptual judgments about the contrast of co-localized visual targets. These findings demonstrate that sudden, intrusive sounds reflexively activate human visual cortex in a spatially specific manner, even during purely auditory tasks when the sounds are not relevant to the ongoing task. PMID:23699530

  13. PALM-COEIN Nomenclature for Abnormal Uterine Bleeding.

    PubMed

    Deneris, Angela

    2016-05-01

    Approximately 30% of women will experience abnormal uterine bleeding (AUB) during their life time. Previous terms defining AUB have been confusing and imprecisely applied. As a consequence, both clinical management and research on this common problem have been negatively impacted. In 2011, the International Federation of Gynecology and Obstetrics (FIGO) Menstrual Disorders Group (FMDG) published PALM-COEIN, a new classification system for abnormal bleeding in the reproductive years. Terms such as menorrhagia, menometrorrhagia, metrorrhagia, dysfunctional uterine bleeding, polymenorrhea, oligomenorrhea, and uterine hemorrhage are no longer recommended. The PALM-COEIN system was developed to standardize nomenclature to describe the etiology and severity of AUB. A brief description of the PALM-COEIN nomenclature is presented as well as treatment options for each etiology. Clinicians will frequently encounter women with AUB and should report findings utilizing the PALM-COEIN system. © 2016 by the American College of Nurse-Midwives.

  14. Visual affective classification by combining visual and text features.

    PubMed

    Liu, Ningning; Wang, Kai; Jin, Xin; Gao, Boyang; Dellandréa, Emmanuel; Chen, Liming

    2017-01-01

    Affective analysis of images in social networks has drawn much attention, and the texts surrounding images are proven to provide valuable semantic meanings about image content, which can hardly be represented by low-level visual features. In this paper, we propose a novel approach for visual affective classification (VAC) task. This approach combines visual representations along with novel text features through a fusion scheme based on Dempster-Shafer (D-S) Evidence Theory. Specifically, we not only investigate different types of visual features and fusion methods for VAC, but also propose textual features to effectively capture emotional semantics from the short text associated to images based on word similarity. Experiments are conducted on three public available databases: the International Affective Picture System (IAPS), the Artistic Photos and the MirFlickr Affect set. The results demonstrate that the proposed approach combining visual and textual features provides promising results for VAC task.

  15. Visual affective classification by combining visual and text features

    PubMed Central

    Liu, Ningning; Wang, Kai; Jin, Xin; Gao, Boyang; Dellandréa, Emmanuel; Chen, Liming

    2017-01-01

    Affective analysis of images in social networks has drawn much attention, and the texts surrounding images are proven to provide valuable semantic meanings about image content, which can hardly be represented by low-level visual features. In this paper, we propose a novel approach for visual affective classification (VAC) task. This approach combines visual representations along with novel text features through a fusion scheme based on Dempster-Shafer (D-S) Evidence Theory. Specifically, we not only investigate different types of visual features and fusion methods for VAC, but also propose textual features to effectively capture emotional semantics from the short text associated to images based on word similarity. Experiments are conducted on three public available databases: the International Affective Picture System (IAPS), the Artistic Photos and the MirFlickr Affect set. The results demonstrate that the proposed approach combining visual and textual features provides promising results for VAC task. PMID:28850566

  16. Visual discrimination in an orangutan (Pongo pygmaeus): measuring visual preference.

    PubMed

    Hanazuka, Yuki; Kurotori, Hidetoshi; Shimizu, Mika; Midorikawa, Akira

    2012-04-01

    Although previous studies have confirmed that trained orangutans visually discriminate between mammals and artificial objects, whether orangutans without operant conditioning can discriminate remains unknown. The visual discrimination ability in an orangutan (Pongo pygmaeus) with no experience in operant learning was examined using measures of visual preference. Sixteen color photographs of inanimate objects and of mammals with four legs were randomly presented to an orangutan. The results showed that the mean looking time at photographs of mammals with four legs was longer than that for inanimate objects, suggesting that the orangutan discriminated mammals with four legs from inanimate objects. The results implied that orangutans who have not experienced operant conditioning may possess the ability to discriminate visually.

  17. Visual function among commercial vehicle drivers in the central region of Ghana.

    PubMed

    Boadi-Kusi, Samuel Bert; Kyei, Samuel; Asare, Frederick Afum; Owusu-Ansah, Andrew; Awuah, Agnes; Darko-Takyi, Charles

    2016-01-01

    To determine the relationship between some visual functions: colour vision defects, abnormal stereopsis, visual acuity and the occurrence of road traffic accident (RTAs) among commercial vehicle drivers in the central region of Ghana, and to assess their knowledge of these anomalies. A descriptive cross-sectional study employing a multi-stage random sampling approach was conducted in the major commercial towns within the central region of Ghana. Participants were taken through a comprehensive eye examination after the administration of a structured questionnaire. 520 male commercial vehicle drivers were enrolled for this study with a mean age of 39.23 years ±10.96 years and mean visual acuity of 0.02±0.08 logMAR. Protans were more likely to be involved in RTAs (χ(2)=6.194, p=0.034). However, there was no statistically significant association between abnormal stereopsis (OR=0.89 95% CI: 0.44-1.80, p=0.56), poor vision due to refractive error (χ(2)=3.090, p=0.388) and the occurrence of RTAs. While 86.9% were aware of abnormal stereopsis, only 45% were aware of colour vision defects. There was a statistically significant association between stereopsis anomaly and colour vision defect (r=0.371, p<0.005). The study found an association between protanopia and RTAs but none between stereopsis anomalies, refractive errors and the occurrence of RTAs. Drivers were less knowledgeable on colour vision defects as compared to stereopsis anomalies. Copyright © 2015 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  18. The mere exposure effect for visual image.

    PubMed

    Inoue, Kazuya; Yagi, Yoshihiko; Sato, Nobuya

    2018-02-01

    Mere exposure effect refers to a phenomenon in which repeated stimuli are evaluated more positively than novel stimuli. We investigated whether this effect occurs for internally generated visual representations (i.e., visual images). In an exposure phase, a 5 × 5 dot array was presented, and a pair of dots corresponding to the neighboring vertices of an invisible polygon was sequentially flashed (in red), creating an invisible polygon. In Experiments 1, 2, and 4, participants visualized and memorized the shapes of invisible polygons based on different sequences of flashed dots, whereas in Experiment 3, participants only memorized positions of these dots. In a subsequent rating phase, participants visualized the shape of the invisible polygon from allocations of numerical characters on its vertices, and then rated their preference for invisible polygons (Experiments 1, 2, and 3). In contrast, in Experiment 4, participants rated the preference for visible polygons. Results showed that the mere exposure effect appeared only when participants visualized the shape of invisible polygons in both the exposure and rating phases (Experiments 1 and 2), suggesting that the mere exposure effect occurred for internalized visual images. This implies that the sensory inputs from repeated stimuli play a minor role in the mere exposure effect. Absence of the mere exposure effect in Experiment 4 suggests that the consistency of processing between exposure and rating phases plays an important role in the mere exposure effect.

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

    PubMed

    Sikl, Radovan; Simeček, Michal

    2014-02-01

    People confined to a closed space live in a visual environment that differs from a natural open-space environment in several respects. The view is restricted to no more than a few meters, and nearby objects cannot be perceived relative to the position of a horizon. Thus, one might expect to find changes in visual space perception as a consequence of the prolonged experience of confinement. The subjects in our experimental study were participants of the Mars-500 project and spent nearly a year and a half isolated from the outside world during a simulated mission to Mars. The participants were presented with a battery of computer-based psychophysical tests examining their performance on various 3-D perception tasks, and we monitored changes in their perceptual performance throughout their confinement. Contrary to our expectations, no serious effect of the confinement on the crewmembers' 3-D perception was observed in any experiment. Several interpretations of these findings are discussed, including the possibilities that (1) the crewmembers' 3-D perception really did not change significantly, (2) changes in 3-D perception were manifested in the precision rather than the accuracy of perceptual judgments, and/or (3) the experimental conditions and the group sample were problematic.

  20. The visual analysis of emotional actions.

    PubMed

    Chouchourelou, Arieta; Matsuka, Toshihiko; Harber, Kent; Shiffrar, Maggie

    2006-01-01

    Is the visual analysis of human actions modulated by the emotional content of those actions? This question is motivated by a consideration of the neuroanatomical connections between visual and emotional areas. Specifically, the superior temporal sulcus (STS), known to play a critical role in the visual detection of action, is extensively interconnected with the amygdala, a center for emotion processing. To the extent that amygdala activity influences STS activity, one would expect to find systematic differences in the visual detection of emotional actions. A series of psychophysical studies tested this prediction. Experiment 1 identified point-light walker movies that convincingly depicted five different emotional states: happiness, sadness, neutral, anger, and fear. In Experiment 2, participants performed a walker detection task with these movies. Detection performance was systematically modulated by the emotional content of the gaits. Participants demonstrated the greatest visual sensitivity to angry walkers. The results of Experiment 3 suggest that local velocity cues to anger may account for high false alarm rates to the presence of angry gaits. These results support the hypothesis that the visual analysis of human action depends upon emotion processes.

  1. Visualizing speciation in artificial cichlid fish.

    PubMed

    Clement, Ross

    2006-01-01

    The Cichlid Speciation Project (CSP) is an ALife simulation system for investigating open problems in the speciation of African cichlid fish. The CSP can be used to perform a wide range of experiments that show that speciation is a natural consequence of certain biological systems. A visualization system capable of extracting the history of speciation from low-level trace data and creating a phylogenetic tree has been implemented. Unlike previous approaches, this visualization system presents a concrete trace of speciation, rather than a summary of low-level information from which the viewer can make subjective decisions on how speciation progressed. The phylogenetic trees are a more objective visualization of speciation, and enable automated collection and summarization of the results of experiments. The visualization system is used to create a phylogenetic tree from an experiment that models sympatric speciation.

  2. Living Independently: Exploring the Experiences of Visually Impaired People Living in Age-Related and Lifetime Housing Through Qualitative Synthesis.

    PubMed

    Rooney, Clíona; Hadjri, Karim; Faith, Verity; Rooney, Máirin; McAllister, Keith; Craig, Cathy

    2017-01-01

    The aim of this study is to gain a deeper understanding of the experiences of visually impaired older people living independently at home. As populations are aging globally, there is now an increase in the prevalence of visual impairment. That means for ongoing and future aging-in-place strategies that seek to enable older people to remain independent for longer, more attention needs to be given to the needs of those with visual impairment. As people develop visual impairment, they use adaptive strategies including modifying long-term homes or relocating to more suitable accommodation. In the United Kingdom, aging-in-place strategies include employing statutory lifetime home standards (LTHS) in the home or relocating to sheltered housing to live independently with support available if required. To get a better understanding of the needs of the visually impaired in the home, 12 interviews with six visually impaired occupants of LTHS homes and six from sheltered accommodation were analyzed separately using interpretative phenomenological analysis. Secondly, qualitative synthesis was used to further analyze themes generated from both samples before interview results were conceptualized in two superordinate concepts, namely, "negotiating priorities" and "understanding visual impairment." Participants from both groups had similar needs and were willing to compromise by living with some negative features. Those who coped well with moving utilized various resources. These findings will shed more understanding on providing good quality housing for those with visual impairment wanting to live either independently or within healthcare home environments.

  3. A Phenomenological Study Exploring the Educational, Vocational and Social Experiences of College Educated Individuals Who Are Visually Impaired

    ERIC Educational Resources Information Center

    Joseph, Mary-Anne M.

    2010-01-01

    Students who are visually impaired have significantly lower educational and vocational success rates than their nondisabled peers (Hasazi, Johnson, Hasazi, Gordon, & Hull, 1989; Nagle, 2001). A qualitative phenomenological study was conducted to explore the educational, vocational and social experiences of college educated individuals who were…

  4. A Model of Successful Work Experience for Employees Who Are Visually Impaired: The Results of a Study

    ERIC Educational Resources Information Center

    Golub, Dawn B.

    2006-01-01

    This study explored the factors that contribute to a successful work experience for employees who are visually impaired from the perspective of employers. The employers who were interviewed emphasized the dual responsibility that employees have to empower their own success and that employers have to enable the employees' success. In addition, an…

  5. Early visual experience and the recognition of basic facial expressions: involvement of the middle temporal and inferior frontal gyri during haptic identification by the early blind.

    PubMed

    Kitada, Ryo; Okamoto, Yuko; Sasaki, Akihiro T; Kochiyama, Takanori; Miyahara, Motohide; Lederman, Susan J; Sadato, Norihiro

    2013-01-01

    Face perception is critical for social communication. Given its fundamental importance in the course of evolution, the innate neural mechanisms can anticipate the computations necessary for representing faces. However, the effect of visual deprivation on the formation of neural mechanisms that underlie face perception is largely unknown. We previously showed that sighted individuals can recognize basic facial expressions by haptics surprisingly well. Moreover, the inferior frontal gyrus (IFG) and posterior superior temporal sulcus (pSTS) in the sighted subjects are involved in haptic and visual recognition of facial expressions. Here, we conducted both psychophysical and functional magnetic-resonance imaging (fMRI) experiments to determine the nature of the neural representation that subserves the recognition of basic facial expressions in early blind individuals. In a psychophysical experiment, both early blind and sighted subjects haptically identified basic facial expressions at levels well above chance. In the subsequent fMRI experiment, both groups haptically identified facial expressions and shoe types (control). The sighted subjects then completed the same task visually. Within brain regions activated by the visual and haptic identification of facial expressions (relative to that of shoes) in the sighted group, corresponding haptic identification in the early blind activated regions in the inferior frontal and middle temporal gyri. These results suggest that the neural system that underlies the recognition of basic facial expressions develops supramodally even in the absence of early visual experience.

  6. Effects of Fluoxetine and Visual Experience on Glutamatergic and GABAergic Synaptic Proteins in Adult Rat Visual Cortex123

    PubMed Central

    Beshara, Simon; Beston, Brett R.; Pinto, Joshua G. A.

    2015-01-01

    Abstract Fluoxetine has emerged as a novel treatment for persistent amblyopia because in adult animals it reinstates critical period-like ocular dominance plasticity and promotes recovery of visual acuity. Translation of these results from animal models to the clinic, however, has been challenging because of the lack of understanding of how this selective serotonin reuptake inhibitor affects glutamatergic and GABAergic synaptic mechanisms that are essential for experience-dependent plasticity. An appealing hypothesis is that fluoxetine recreates a critical period (CP)-like state by shifting synaptic mechanisms to be more juvenile. To test this we studied the effect of fluoxetine treatment in adult rats, alone or in combination with visual deprivation [monocular deprivation (MD)], on a set of highly conserved presynaptic and postsynaptic proteins (synapsin, synaptophysin, VGLUT1, VGAT, PSD-95, gephyrin, GluN1, GluA2, GluN2B, GluN2A, GABAAα1, GABAAα3). We did not find evidence that fluoxetine shifted the protein amounts or balances to a CP-like state. Instead, it drove the balances in favor of the more mature subunits (GluN2A, GABAAα1). In addition, when fluoxetine was paired with MD it created a neuroprotective-like environment by normalizing the glutamatergic gain found in adult MDs. Together, our results suggest that fluoxetine treatment creates a novel synaptic environment dominated by GluN2A- and GABAAα1-dependent plasticity. PMID:26730408

  7. How (and why) the visual control of action differs from visual perception

    PubMed Central

    Goodale, Melvyn A.

    2014-01-01

    Vision not only provides us with detailed knowledge of the world beyond our bodies, but it also guides our actions with respect to objects and events in that world. The computations required for vision-for-perception are quite different from those required for vision-for-action. The former uses relational metrics and scene-based frames of reference while the latter uses absolute metrics and effector-based frames of reference. These competing demands on vision have shaped the organization of the visual pathways in the primate brain, particularly within the visual areas of the cerebral cortex. The ventral ‘perceptual’ stream, projecting from early visual areas to inferior temporal cortex, helps to construct the rich and detailed visual representations of the world that allow us to identify objects and events, attach meaning and significance to them and establish their causal relations. By contrast, the dorsal ‘action’ stream, projecting from early visual areas to the posterior parietal cortex, plays a critical role in the real-time control of action, transforming information about the location and disposition of goal objects into the coordinate frames of the effectors being used to perform the action. The idea of two visual systems in a single brain might seem initially counterintuitive. Our visual experience of the world is so compelling that it is hard to believe that some other quite independent visual signal—one that we are unaware of—is guiding our movements. But evidence from a broad range of studies from neuropsychology to neuroimaging has shown that the visual signals that give us our experience of objects and events in the world are not the same ones that control our actions. PMID:24789899

  8. Temporal Structure and Complexity Affect Audio-Visual Correspondence Detection

    PubMed Central

    Denison, Rachel N.; Driver, Jon; Ruff, Christian C.

    2013-01-01

    Synchrony between events in different senses has long been considered the critical temporal cue for multisensory integration. Here, using rapid streams of auditory and visual events, we demonstrate how humans can use temporal structure (rather than mere temporal coincidence) to detect multisensory relatedness. We find psychophysically that participants can detect matching auditory and visual streams via shared temporal structure for crossmodal lags of up to 200 ms. Performance on this task reproduced features of past findings based on explicit timing judgments but did not show any special advantage for perfectly synchronous streams. Importantly, the complexity of temporal patterns influences sensitivity to correspondence. Stochastic, irregular streams – with richer temporal pattern information – led to higher audio-visual matching sensitivity than predictable, rhythmic streams. Our results reveal that temporal structure and its complexity are key determinants for human detection of audio-visual correspondence. The distinctive emphasis of our new paradigms on temporal patterning could be useful for studying special populations with suspected abnormalities in audio-visual temporal perception and multisensory integration. PMID:23346067

  9. Detecting Visually Observable Disease Symptoms from Faces.

    PubMed

    Wang, Kuan; Luo, Jiebo

    2016-12-01

    Recent years have witnessed an increasing interest in the application of machine learning to clinical informatics and healthcare systems. A significant amount of research has been done on healthcare systems based on supervised learning. In this study, we present a generalized solution to detect visually observable symptoms on faces using semi-supervised anomaly detection combined with machine vision algorithms. We rely on the disease-related statistical facts to detect abnormalities and classify them into multiple categories to narrow down the possible medical reasons of detecting. Our method is in contrast with most existing approaches, which are limited by the availability of labeled training data required for supervised learning, and therefore offers the major advantage of flagging any unusual and visually observable symptoms.

  10. Detection of Cardiac Abnormalities from Multilead ECG using Multiscale Phase Alternation Features.

    PubMed

    Tripathy, R K; Dandapat, S

    2016-06-01

    The cardiac activities such as the depolarization and the relaxation of atria and ventricles are observed in electrocardiogram (ECG). The changes in the morphological features of ECG are the symptoms of particular heart pathology. It is a cumbersome task for medical experts to visually identify any subtle changes in the morphological features during 24 hours of ECG recording. Therefore, the automated analysis of ECG signal is a need for accurate detection of cardiac abnormalities. In this paper, a novel method for automated detection of cardiac abnormalities from multilead ECG is proposed. The method uses multiscale phase alternation (PA) features of multilead ECG and two classifiers, k-nearest neighbor (KNN) and fuzzy KNN for classification of bundle branch block (BBB), myocardial infarction (MI), heart muscle defect (HMD) and healthy control (HC). The dual tree complex wavelet transform (DTCWT) is used to decompose the ECG signal of each lead into complex wavelet coefficients at different scales. The phase of the complex wavelet coefficients is computed and the PA values at each wavelet scale are used as features for detection and classification of cardiac abnormalities. A publicly available multilead ECG database (PTB database) is used for testing of the proposed method. The experimental results show that, the proposed multiscale PA features and the fuzzy KNN classifier have better performance for detection of cardiac abnormalities with sensitivity values of 78.12 %, 80.90 % and 94.31 % for BBB, HMD and MI classes. The sensitivity value of proposed method for MI class is compared with the state-of-art techniques from multilead ECG.

  11. Periventricular Nodular Heterotopia: Detection of Abnormal Microanatomic Fiber Structures with Whole-Brain Diffusion MR Imaging Tractography.

    PubMed

    Farquharson, Shawna; Tournier, J-Donald; Calamante, Fernando; Mandelstam, Simone; Burgess, Rosemary; Schneider, Michal E; Berkovic, Samuel F; Scheffer, Ingrid E; Jackson, Graeme D; Connelly, Alan

    2016-12-01

    Purpose To investigate whether it is possible in patients with periventricular nodular heterotopia (PVNH) to detect abnormal fiber projections that have only previously been reported in the histopathology literature. Materials and Methods Whole-brain diffusion-weighted (DW) imaging data from 14 patients with bilateral PVNH and 14 age- and sex-matched healthy control subjects were prospectively acquired by using 3.0-T magnetic resonance (MR) imaging between August 1, 2008, and December 5, 2012. All participants provided written informed consent. The DW imaging data were processed to generate whole-brain constrained spherical deconvolution (CSD)-based tractography data and super-resolution track-density imaging (TDI) maps. The tractography data were overlaid on coregistered three-dimensional T1-weighted images to visually assess regions of heterotopia. A panel of MR imaging researchers independently assessed each case and indicated numerically (no = 1, yes = 2) as to the presence of abnormal fiber tracks in nodular tissue. The Fleiss κ statistical measure was applied to assess the reader agreement. Results Abnormal fiber tracks emanating from one or more regions of heterotopia were reported by all four readers in all 14 patients with PVNH (Fleiss κ = 1). These abnormal structures were not visible on the tractography data from any of the control subjects and were not discernable on the conventional T1-weighted images of the patients with PVNH. Conclusion Whole-brain CSD-based fiber tractography and super-resolution TDI mapping reveals abnormal fiber projections in nodular tissue suggestive of abnormal organization of white matter (with abnormal fibers both within nodules and projecting to the surrounding white matter) in patients with bilateral PVNH. © RSNA, 2016.

  12. Visual-motor recalibration in geographical slant perception

    NASA Technical Reports Server (NTRS)

    Bhalla, M.; Proffitt, D. R.; Kaiser, M. K. (Principal Investigator)

    1999-01-01

    In 4 experiments, it was shown that hills appear steeper to people who are encumbered by wearing a heavy backpack (Experiment 1), are fatigued (Experiment 2), are of low physical fitness (Experiment 3), or are elderly and/or in declining health (Experiment 4). Visually guided actions are unaffected by these manipulations of physiological potential. Although dissociable, the awareness and action systems were also shown to be interconnected. Recalibration of the transformation relating awareness and actions was found to occur over long-term changes in physiological potential (fitness level, age, and health) but not with transitory changes (fatigue and load). Findings are discussed in terms of a time-dependent coordination between the separate systems that control explicit visual awareness and visually guided action.

  13. Neurofeedback in Learning Disabled Children: Visual versus Auditory Reinforcement.

    PubMed

    Fernández, Thalía; Bosch-Bayard, Jorge; Harmony, Thalía; Caballero, María I; Díaz-Comas, Lourdes; Galán, Lídice; Ricardo-Garcell, Josefina; Aubert, Eduardo; Otero-Ojeda, Gloria

    2016-03-01

    Children with learning disabilities (LD) frequently have an EEG characterized by an excess of theta and a deficit of alpha activities. NFB using an auditory stimulus as reinforcer has proven to be a useful tool to treat LD children by positively reinforcing decreases of the theta/alpha ratio. The aim of the present study was to optimize the NFB procedure by comparing the efficacy of visual (with eyes open) versus auditory (with eyes closed) reinforcers. Twenty LD children with an abnormally high theta/alpha ratio were randomly assigned to the Auditory or the Visual group, where a 500 Hz tone or a visual stimulus (a white square), respectively, was used as a positive reinforcer when the value of the theta/alpha ratio was reduced. Both groups had signs consistent with EEG maturation, but only the Auditory Group showed behavioral/cognitive improvements. In conclusion, the auditory reinforcer was more efficacious in reducing the theta/alpha ratio, and it improved the cognitive abilities more than the visual reinforcer.

  14. The experience of reading.

    PubMed

    Moore, Alan Tonnies; Schwitzgebel, Eric

    2018-05-03

    What do people consciously experience when they read? There has been almost no rigorous research on this question, and opinions diverge radically among both philosophers and psychologists. We describe three studies of the phenomenology of reading and its relationship to memory of textual detail and general cognitive abilities. We find three main results. First, there is substantial variability in reports about reading experience, both within and between participants. Second, reported reading experience varies with passage type: passages with dialogue prompted increased reports of inner speech, while passages with vivid visual detail prompted increased reports of visual imagery. Third, reports of visual imagery experiences, inner speech experiences, and experiences of conscious visual perception of the words on the page were at best weakly related to general cognitive abilities and memory of visual and auditory details. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Food shopping, sensory determinants of food choice and meal preparation by visually impaired people. Obstacles and expectations in daily food experiences.

    PubMed

    Kostyra, Eliza; Żakowska-Biemans, Sylwia; Śniegocka, Katarzyna; Piotrowska, Anna

    2017-06-01

    The number of visually impaired and blind people is rising worldwide due to ageing of the global population, but research regarding the impact of visual impairment on the ability of a person to choose food and to prepare meals is scarce. The aim of this study was threefold: to investigate factors determining the choices of food products in people with various levels of impaired vision; to identify obstacles they face while purchasing food, preparing meals and eating out; and to determine what would help them in the areas of food shopping and meal preparation. The data was collected from 250 blind and visually impaired subjects, recruited with the support of the National Association of the Blind. The study revealed that majority of the visually impaired make food purchases at a supermarket or local grocery and they tend to favour shopping for food via the Internet. Direct sale channels like farmers markets were rarely used by the visually impaired. The most frequently mentioned factors that facilitated their food shopping decisions were the assistance of salespersons, product labelling in Braille, scanners that enable the reading of labels and a permanent place for products on the shop shelves. Meal preparation, particularly peeling, slicing and frying, posed many challenges to the visually impaired. More than half of the respondents ate meals outside the home, mainly with family or friends. The helpfulness of the staff and a menu in Braille were crucial for them to have a positive dining out experience. The results of the study provide valuable insights into the food choices and eating experiences of visually impaired people, and also suggest some practical implications to improve their independence and quality of life. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    PubMed

    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.

  17. Inter- and intra-observer agreement of BI-RADS-based subjective visual estimation of amount of fibroglandular breast tissue with magnetic resonance imaging: comparison to automated quantitative assessment.

    PubMed

    Wengert, G J; Helbich, T H; Woitek, R; Kapetas, P; Clauser, P; Baltzer, P A; Vogl, W-D; Weber, M; Meyer-Baese, A; Pinker, Katja

    2016-11-01

    To evaluate the inter-/intra-observer agreement of BI-RADS-based subjective visual estimation of the amount of fibroglandular tissue (FGT) with magnetic resonance imaging (MRI), and to investigate whether FGT assessment benefits from an automated, observer-independent, quantitative MRI measurement by comparing both approaches. Eighty women with no imaging abnormalities (BI-RADS 1 and 2) were included in this institutional review board (IRB)-approved prospective study. All women underwent un-enhanced breast MRI. Four radiologists independently assessed FGT with MRI by subjective visual estimation according to BI-RADS. Automated observer-independent quantitative measurement of FGT with MRI was performed using a previously described measurement system. Inter-/intra-observer agreements of qualitative and quantitative FGT measurements were assessed using Cohen's kappa (k). Inexperienced readers achieved moderate inter-/intra-observer agreement and experienced readers a substantial inter- and perfect intra-observer agreement for subjective visual estimation of FGT. Practice and experience reduced observer-dependency. Automated observer-independent quantitative measurement of FGT was successfully performed and revealed only fair to moderate agreement (k = 0.209-0.497) with subjective visual estimations of FGT. Subjective visual estimation of FGT with MRI shows moderate intra-/inter-observer agreement, which can be improved by practice and experience. Automated observer-independent quantitative measurements of FGT are necessary to allow a standardized risk evaluation. • Subjective FGT estimation with MRI shows moderate intra-/inter-observer agreement in inexperienced readers. • Inter-observer agreement can be improved by practice and experience. • Automated observer-independent quantitative measurements can provide reliable and standardized assessment of FGT with MRI.

  18. Stimulation from Cochlear Implant Electrodes Assists with Recovery from Asymmetric Perceptual Tilt: Evidence from the Subjective Visual Vertical Test

    PubMed Central

    Gnanasegaram, Joshua J.; Parkes, William J.; Cushing, Sharon L.; McKnight, Carmen L.; Papsin, Blake C.; Gordon, Karen A.

    2016-01-01

    Vestibular end organ impairment is highly prevalent in children who have sensorineural hearing loss (SNHL) rehabilitated with cochlear implants (CIs). As a result, spatial perception is likely to be impacted in this population. Of particular interest is the perception of visual vertical because it reflects a perceptual tilt in the roll axis and is sensitive to an imbalance in otolith function. The objectives of the present study were thus to identify abnormalities in perception of the vertical plane in children with SNHL and determine whether such abnormalities could be resolved with stimulation from the CI. Participants included 53 children (15.2 ± 4.0 years of age) with SNHL and vestibular loss, confirmed with vestibular evoked myogenic potential (VEMP) testing. Testing protocol was validated in a sample of nine young adults with normal hearing (28.8 ± 7.7 years). Perception of visual vertical was assessed using the static Subjective Visual Vertical (SVV) test performed with and without stimulation in the participants with cochleovestibular loss. Trains of electrical pulses were delivered by an electrode in the left and/or right ear. Asymmetric spatial orientation deficits were found in nearly half of the participants with CIs (24/53 [45%]). The abnormal perception in this cohort was exacerbated by visual tilts in the direction of their deficit. Electric pulse trains delivered using the CI shifted this abnormal perception towards center (i.e., normal; p = 0.007). Importantly, this benefit was realized regardless of which ear was stimulated. These results suggest a role for CI stimulation beyond the auditory system, in particular, for improving vestibular/balance function. PMID:27679562

  19. A survey on the knowledge and attitudes of anaesthesia providers in the United States of America, United Kingdom and Singapore on visual experiences during cataract surgery.

    PubMed

    Tan, C S H; Kumar, C M; Fanning, G L; Lai, Y C; Au Eong, K G

    2006-04-01

    To assess the knowledge, beliefs and attitudes of anaesthesia providers on the patients' possible intraoperative visual experiences during cataract surgery under local anaesthesia. Anaesthesia providers from the Ophthalmic Anaesthesia Society (USA); British Ophthalmic Anaesthesia Society (UK); Alexandra Hospital, National University Hospital, Tan Tock Seng Hospital, Singapore General Hospital and Changi General Hospital (Singapore) were surveyed using a structured questionnaire. A total of 146 anaesthesiologists (81.6%), 10 ophthalmologists (5.6%) and 23 nurse anaesthetists (12.8%) responded to the survey. Most respondents believed that patients would experience light perception and many also felt that patients might encounter other visual sensations such as movements, flashes, colours, surgical instruments, hands/fingers and the surgeon during the surgery. A significantly higher proportion of anaesthesia providers with previous experience of monitoring patients under topical anaesthesia believed that patients might experience the various visual sensations compared to those who have not previously monitored. For both topical and regional anaesthesia, anaesthesia providers who routinely counsel their patients are (1) more likely to believe that preoperative counselling helps or (2) were previously told by patients that they could see intraoperatively and/or that they were frightened by their visual sensations. These findings were statistically significant. The majority of anaesthesia providers in the USA, UK and Singapore are aware that patients may experience a variety of visual sensations during cataract surgery under regional or topical anaesthesia. Those who have previously managed patients undergoing cataract surgery under topical anaesthesia are more likely to believe this compared to those who have not.

  20. How the mechanisms of long-term synaptic potentiation and depression serve experience-dependent plasticity in primary visual cortex

    PubMed Central

    Cooke, Sam F.; Bear, Mark F.

    2014-01-01

    Donald Hebb chose visual learning in primary visual cortex (V1) of the rodent to exemplify his theories of how the brain stores information through long-lasting homosynaptic plasticity. Here, we revisit V1 to consider roles for bidirectional ‘Hebbian’ plasticity in the modification of vision through experience. First, we discuss the consequences of monocular deprivation (MD) in the mouse, which have been studied by many laboratories over many years, and the evidence that synaptic depression of excitatory input from the thalamus is a primary contributor to the loss of visual cortical responsiveness to stimuli viewed through the deprived eye. Second, we describe a less studied, but no less interesting form of plasticity in the visual cortex known as stimulus-selective response potentiation (SRP). SRP results in increases in the response of V1 to a visual stimulus through repeated viewing and bears all the hallmarks of perceptual learning. We describe evidence implicating an important role for potentiation of thalamo-cortical synapses in SRP. In addition, we present new data indicating that there are some features of this form of plasticity that cannot be fully accounted for by such feed-forward Hebbian plasticity, suggesting contributions from intra-cortical circuit components. PMID:24298166

  1. Visual Field Asymmetry in Attentional Capture

    ERIC Educational Resources Information Center

    Du, Feng; Abrams, Richard A.

    2010-01-01

    The present study examined the spatial distribution of involuntary attentional capture over the two visual hemi-fields. A new experiment, and an analysis of three previous experiments showed that distractors in the left visual field that matched a sought-for target in color produced a much larger capture effect than identical distractors in the…

  2. Induced Abnormality In Mir- and Earth-Grown Super Dwarf Wheat

    NASA Technical Reports Server (NTRS)

    Bubenheim, David L.; Stieber, Joseph; Campbell, William F.; Salisbury, Frank B.; Levinski, Margarita; Sytchev, Vladimir; Podolsky, Igor; Chernova, Lola; Ivanova, Irene; Kliss, Mark (Technical Monitor)

    1998-01-01

    Super-dwarf wheat grown on the Mir space station using the Svet "Greenhouse" exhibited morphological, metabolic and reproductive abnormalities compared with normal wheat. Of prominent importance were the abnormalities associated with reproductive ontogeny and the total absence of seed formation on Mir. Changes in the apical meristem associated with transition from the vegetative phase to floral initiation and development of the reproductive spike were all typical of 'Super Dwarf' wheat up to the point of anthesis. Observation of ruptured anthers from the Mir-grown plants revealed what appeared to be normally developed pollen. These pollen grains however, contain only one nucleus, while normal viable pollen is trinucleate. A potentially important difference in the flight experiment, compared with ground reference studies, was identified - a high level of atmospheric ethylene (1200 ppb). Ground studies conducted exposing "Super-dwarf" wheat to ethylene at just prior to anthesis resulted in manifestation of the same abnormalities observed in the space flight samples.

  3. Visual form-processing deficits: a global clinical classification.

    PubMed

    Unzueta-Arce, J; García-García, R; Ladera-Fernández, V; Perea-Bartolomé, M V; Mora-Simón, S; Cacho-Gutiérrez, J

    2014-10-01

    Patients who have difficulties recognising visual form stimuli are usually labelled as having visual agnosia. However, recent studies let us identify different clinical manifestations corresponding to discrete diagnostic entities which reflect a variety of deficits along the continuum of cortical visual processing. We reviewed different clinical cases published in medical literature as well as proposals for classifying deficits in order to provide a global perspective of the subject. Here, we present the main findings on the neuroanatomical basis of visual form processing and discuss the criteria for evaluating processing which may be abnormal. We also include an inclusive diagram of visual form processing deficits which represents the different clinical cases described in the literature. Lastly, we propose a boosted decision tree to serve as a guide in the process of diagnosing such cases. Although the medical community largely agrees on which cortical areas and neuronal circuits are involved in visual processing, future studies making use of new functional neuroimaging techniques will provide more in-depth information. A well-structured and exhaustive assessment of the different stages of visual processing, designed with a global view of the deficit in mind, will give a better idea of the prognosis and serve as a basis for planning personalised psychostimulation and rehabilitation strategies. Copyright © 2011 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

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

    PubMed

    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.

  5. Visual experience and subsequent sleep induce sequential plastic changes in putative inhibitory and excitatory cortical neurons

    PubMed Central

    Aton, Sara J.; Broussard, Christopher; Dumoulin, Michelle; Seibt, Julie; Watson, Adam; Coleman, Tammi; Frank, Marcos G.

    2013-01-01

    Ocular dominance plasticity in the developing primary visual cortex is initiated by monocular deprivation (MD) and consolidated during subsequent sleep. To clarify how visual experience and sleep affect neuronal activity and plasticity, we continuously recorded extragranular visual cortex fast-spiking (FS) interneurons and putative principal (i.e., excitatory) neurons in freely behaving cats across periods of waking MD and post-MD sleep. Consistent with previous reports in mice, MD induces two related changes in FS interneurons: a response shift in favor of the closed eye and depression of firing. Spike-timing–dependent depression of open-eye–biased principal neuron inputs to FS interneurons may mediate these effects. During post-MD nonrapid eye movement sleep, principal neuron firing increases and becomes more phase-locked to slow wave and spindle oscillations. Ocular dominance (OD) shifts in favor of open-eye stimulation—evident only after post-MD sleep—are proportional to MD-induced changes in FS interneuron activity and to subsequent sleep-associated changes in principal neuron activity. OD shifts are greatest in principal neurons that fire 40–300 ms after neighboring FS interneurons during post-MD slow waves. Based on these data, we propose that MD-induced changes in FS interneurons play an instructive role in ocular dominance plasticity, causing disinhibition among open-eye–biased principal neurons, which drive plasticity throughout the visual cortex during subsequent sleep. PMID:23300282

  6. Early detection of subclinical visual damage after blast-mediated TBI enables prevention of chronic visual deficit by treatment with P7C3-S243.

    PubMed

    Dutca, Laura M; Stasheff, Steven F; Hedberg-Buenz, Adam; Rudd, Danielle S; Batra, Nikhil; Blodi, Frederick R; Yorek, Matthew S; Yin, Terry; Shankar, Malini; Herlein, Judith A; Naidoo, Jacinth; Morlock, Lorraine; Williams, Noelle; Kardon, Randy H; Anderson, Michael G; Pieper, Andrew A; Harper, Matthew M

    2014-12-02

    Traumatic brain injury (TBI) frequently leads to chronic visual dysfunction. The purpose of this study was to investigate the effect of TBI on retinal ganglion cells (RGCs), and to test whether treatment with the novel neuroprotective compound P7C3-S243 could prevent in vivo functional deficits in the visual system. Blast-mediated TBI was modeled using an enclosed over-pressure blast chamber. The RGC physiology was evaluated using a multielectrode array and pattern electroretinogram (PERG). Histological analysis of RGC dendritic field and cell number were evaluated at the end of the study. Visual outcome measures also were evaluated based on treatment of mice with P7C3-S243 or vehicle control. We show that deficits in neutral position PERG after blast-mediated TBI occur in a temporally bimodal fashion, with temporary recovery 4 weeks after injury followed by chronically persistent dysfunction 12 weeks later. This later time point is associated with development of dendritic abnormalities and irreversible death of RGCs. We also demonstrate that ongoing pathologic processes during the temporary recovery latent period (including abnormalities of RGC physiology) lead to future dysfunction of the visual system. We report that modification of PERG to provocative postural tilt testing elicits changes in PERG measurements that correlate with a key in vitro measures of damage: the spontaneous and light-evoked activity of RGCs. Treatment with P7C3-S243 immediately after injury and throughout the temporary recovery latent period protects mice from developing chronic visual system dysfunction. Provocative PERG testing serves as a noninvasive test in the living organism to identify early damage to the visual system, which may reflect corresponding damage in the brain that is not otherwise detectable by noninvasive means. This provides the basis for developing an earlier diagnostic test to identify patients at risk for developing chronic CNS and visual system damage after TBI at

  7. Early Detection of Subclinical Visual Damage After Blast-Mediated TBI Enables Prevention of Chronic Visual Deficit by Treatment With P7C3-S243

    PubMed Central

    Dutca, Laura M.; Stasheff, Steven F.; Hedberg-Buenz, Adam; Rudd, Danielle S.; Batra, Nikhil; Blodi, Frederick R.; Yorek, Matthew S.; Yin, Terry; Shankar, Malini; Herlein, Judith A.; Naidoo, Jacinth; Morlock, Lorraine; Williams, Noelle; Kardon, Randy H.; Anderson, Michael G.; Pieper, Andrew A.; Harper, Matthew M.

    2014-01-01

    Purpose. Traumatic brain injury (TBI) frequently leads to chronic visual dysfunction. The purpose of this study was to investigate the effect of TBI on retinal ganglion cells (RGCs), and to test whether treatment with the novel neuroprotective compound P7C3-S243 could prevent in vivo functional deficits in the visual system. Methods. Blast-mediated TBI was modeled using an enclosed over-pressure blast chamber. The RGC physiology was evaluated using a multielectrode array and pattern electroretinogram (PERG). Histological analysis of RGC dendritic field and cell number were evaluated at the end of the study. Visual outcome measures also were evaluated based on treatment of mice with P7C3-S243 or vehicle control. Results. We show that deficits in neutral position PERG after blast-mediated TBI occur in a temporally bimodal fashion, with temporary recovery 4 weeks after injury followed by chronically persistent dysfunction 12 weeks later. This later time point is associated with development of dendritic abnormalities and irreversible death of RGCs. We also demonstrate that ongoing pathologic processes during the temporary recovery latent period (including abnormalities of RGC physiology) lead to future dysfunction of the visual system. We report that modification of PERG to provocative postural tilt testing elicits changes in PERG measurements that correlate with a key in vitro measures of damage: the spontaneous and light-evoked activity of RGCs. Treatment with P7C3-S243 immediately after injury and throughout the temporary recovery latent period protects mice from developing chronic visual system dysfunction. Conclusions. Provocative PERG testing serves as a noninvasive test in the living organism to identify early damage to the visual system, which may reflect corresponding damage in the brain that is not otherwise detectable by noninvasive means. This provides the basis for developing an earlier diagnostic test to identify patients at risk for developing chronic

  8. Pediatric Patients Discharged from the Emergency Department with Abnormal Vital Signs.

    PubMed

    Winter, Josephine; Waxman, Michael J; Waterman, George; Ata, Ashar; Frisch, Adam; Collins, Kevin P; King, Christopher

    2017-08-01

    Children often present to the emergency department (ED) with minor conditions such as fever and have persistently abnormal vital signs. We hypothesized that a significant portion of children discharged from the ED would have abnormal vital signs and that those discharged with abnormal vital signs would experience very few adverse events. We performed a retrospective chart review encompassing a 44-month period of all pediatric patients (aged two months to 17 years) who were discharged from the ED with an abnormal pulse rate, respiratory rate, temperature, or oxygen saturation. We used a local quality assurance database to identify pre-defined adverse events after discharge in this population. Our primary aim was to determine the proportion of children discharged with abnormal vital signs and the frequency and nature of adverse events. Additionally, we performed a sub-analysis comparing the rate of adverse events in children discharged with normal vs. abnormal vital signs, as well as a standardized review of the nature of each adverse event. Of 33,185 children discharged during the study period, 5,540 (17%) of these patients had at least one abnormal vital sign. There were 24/5,540 (0.43%) adverse events in the children with at least one abnormal vital sign vs. 47/27,645 (0.17%) adverse events in the children with normal vital signs [relative risk = 2.5 (95% confidence interval, 1.6 to 2.4)].However, upon review of each adverse event we found only one case that was related to the index visit, was potentially preventable by a 23-hour hospital observation, and caused permanent disability. In our study population, 17% of the children were discharged with at least one abnormal vital sign, and there were very few adverse (0.43%) events associated with this practice. Heart rate was the most common abnormal vital sign leading to an adverse event. Severe adverse events that were potentially related to the abnormal vital sign(s) were exceedingly rare. Additional research is

  9. Electrocardiographic abnormalities in opiate addicts.

    PubMed

    Wallner, Christina; Stöllberger, Claudia; Hlavin, Anton; Finsterer, Josef; Hager, Isabella; Hermann, Peter

    2008-12-01

    To determine in a cross-sectional study the prevalence of electrocardiographic (ECG) abnormalities in opiate addicts who were therapy-seeking and its association with demographic, clinical and drug-specific parameters. In consecutive therapy-seeking opiate addicts, a 12-lead ECG was registered within 24 hours after admission and evaluated according to a pre-set protocol between October 2004 and August 2006. Additionally, demographic, clinical and drug-specific parameters were recorded. Included were 511 opiate-addicts, 25% female, with a mean age of 29 years (range 17-59 years). One or more ECG abnormalities were found in 314 patients (61%). In the 511 patients we found most commonly ST abnormalities (19%), QTc prolongation (13%), tall R- and/or S-waves (11%) and missing R progression (10%). ECG abnormalities were more common in males than in females (64 versus 54%, P < 0.05), and in patients with positive than negative urine findings for cannabis (68 versus 57%, P < 0.05). Patients with ST abnormalities were more often males than females (21 versus 11%, P < 0.05), had a history of seizures less often (16 versus 27%, P < 0.05), had positive than negative urine findings for cannabis more often (26 versus 15%, P < 0.01) and had negative than positive urine findings for methadone more often (21 versus 11%, P < 0.05). QTc prolongation was more frequent in patients with high dosages of maintenance drugs than in patients with medium or low dosages (27 versus 12 versus 10%, P < 0.05) and in patients whose urine findings were positive than negative for methadone (23 versus 11%, P < 0.001) as well as for benzodiazepines (17 versus 9%, P < 0.05). Limitations of the data are that in most cases other risk factors for the cardiac abnormalities were not known. ECG abnormalities are frequent in opiate addicts. The most frequent ECG abnormalities are ST abnormalities, QTc prolongation and tall R- and/or S-waves. ST abnormalities are associated with cannabis, and QTc prolongation

  10. Abnormalities of the erythrocyte membrane.

    PubMed

    Gallagher, Patrick G

    2013-12-01

    Primary abnormalities of the erythrocyte membrane are characterized by clinical, laboratory, and genetic heterogeneity. Among this group, hereditary spherocytosis patients are more likely to experience symptomatic anemia. Treatment of hereditary spherocytosis with splenectomy is curative in most patients. Growing recognition of the long-term risks of splenectomy has led to re-evaluation of the role of splenectomy. Management guidelines acknowledge these considerations and recommend discussion between health care providers, patient, and family. The hereditary elliptocytosis syndromes are the most common primary disorders of erythrocyte membrane proteins. However, most elliptocytosis patients are asymptomatic and do not require therapy. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Visual and vestibular components of motion sickness.

    PubMed

    Eyeson-Annan, M; Peterken, C; Brown, B; Atchison, D

    1996-10-01

    The relative importance of visual and vestibular information in the etiology of motion sickness (MS) is not well understood, but these factors can be manipulated by inducing Coriolis and pseudo-Coriolis effects in experimental subjects. We hypothesized that visual and vestibular information are equivalent in producing MS. The experiments reported here aim, in part, to examine the relative influence of Coriolis and pseudo-Coriolis effects in inducing MS. We induced MS symptoms by combinations of whole body rotation and tilt, and environment rotation and tilt, in 22 volunteer subjects. Subjects participated in all of the experiments with at least 2 d between each experiment to dissipate after-effects. We recorded MS signs and symptoms when only visual stimulation was applied, when only vestibular stimulation was applied, and when both visual and vestibular stimulation were applied under specific conditions of whole body and environmental tilt. Visual stimuli produced more symptoms of MS than vestibular stimuli when only visual or vestibular stimuli were used (ANOVA F = 7.94, df = 1, 21 p = 0.01), but there was no significant difference in MS production when combined visual and vestibular stimulation were used to produce the Coriolis effect or pseudo-Coriolis effect (ANOVA: F = 0.40, df = 1, 21 p = 0.53). This was further confirmed by examination of the order in which the symptoms occurred and the lack of a correlation between previous experience and visually induced MS. Visual information is more important than vestibular input in causing MS when these stimuli are presented in isolation. In conditions where both visual and vestibular information are present, cross-coupling appears to occur between the pseudo-Coriolis effect and the Coriolis effect, as these two conditions are not significantly different in producing MS symptoms.

  12. Reading in the dark: neural correlates and cross-modal plasticity for learning to read entire words without visual experience.

    PubMed

    Sigalov, Nadine; Maidenbaum, Shachar; Amedi, Amir

    2016-03-01

    Cognitive neuroscience has long attempted to determine the ways in which cortical selectivity develops, and the impact of nature vs. nurture on it. Congenital blindness (CB) offers a unique opportunity to test this question as the brains of blind individuals develop without visual experience. Here we approach this question through the reading network. Several areas in the visual cortex have been implicated as part of the reading network, and one of the main ones among them is the VWFA, which is selective to the form of letters and words. But what happens in the CB brain? On the one hand, it has been shown that cross-modal plasticity leads to the recruitment of occipital areas, including the VWFA, for linguistic tasks. On the other hand, we have recently demonstrated VWFA activity for letters in contrast to other visual categories when the information is provided via other senses such as touch or audition. Which of these tasks is more dominant? By which mechanism does the CB brain process reading? Using fMRI and visual-to-auditory sensory substitution which transfers the topographical features of the letters we compare reading with semantic and scrambled conditions in a group of CB. We found activation in early auditory and visual cortices during the early processing phase (letter), while the later phase (word) showed VWFA and bilateral dorsal-intraparietal activations for words. This further supports the notion that many visual regions in general, even early visual areas, also maintain a predilection for task processing even when the modality is variable and in spite of putative lifelong linguistic cross-modal plasticity. Furthermore, we find that the VWFA is recruited preferentially for letter and word form, while it was not recruited, and even exhibited deactivation, for an immediately subsequent semantic task suggesting that despite only short sensory substitution experience orthographic task processing can dominate semantic processing in the VWFA. On a wider

  13. Predictive value of background experiences and visual spatial ability testing on laparoscopic baseline performance among residents entering postgraduate surgical training.

    PubMed

    Louridas, Marisa; Quinn, Lauren E; Grantcharov, Teodor P

    2016-03-01

    Emerging evidence suggests that despite dedicated practice, not all surgical trainees have the ability to reach technical competency in minimally invasive techniques. While selecting residents that have the ability to reach technical competence is important, evidence to guide the incorporation of technical ability into selection processes is limited. Therefore, the purpose of the present study was to evaluate whether background experiences and 2D-3D visual spatial test results are predictive of baseline laparoscopic skill for the novice surgical trainee. First-year residents were studied. Demographic data and background surgical and non-surgical experiences were obtained using a questionnaire. Visual spatial ability was evaluated using the PicSOr, cube comparison (CC) and card rotation (CR) tests. Technical skill was assessed using the camera navigation (LCN) task and laparoscopic circle cut (LCC) task. Resident performance on these technical tasks was compared and correlated with the questionnaire and visual spatial findings. Previous experience in observing laparoscopic procedures was associated with significantly better LCN performance, and experience in navigating the laparoscopic camera was associated with significantly better LCC task results. Residents who scored higher on the CC test demonstrated a more accurate LCN path length score (r s(PL) = -0.36, p = 0.03) and angle path (r s(AP) = -0.426, p = 0.01) score when completing the LCN task. No other significant correlations were found between the visual spatial tests (PicSOr, CC or CR) and LCC performance. While identifying selection tests for incoming surgical trainees that predict technical skill performance is appealing, the surrogate markers evaluated correlate with specific metrics of surgical performance related to a single task but do not appear to reliably predict technical performance of different laparoscopic tasks. Predicting the acquisition of technical skills will require the development

  14. The Effects of Realism in Learning with Dynamic Visualizations

    ERIC Educational Resources Information Center

    Scheiter, Katharina; Gerjets, Peter; Huk, Thomas; Imhof, Birgit; Kammerer, Yvonne

    2009-01-01

    Two experiments are reported that investigated the relative effectiveness of a realistic dynamic visualization as opposed to a schematic visualization for learning about cell replication (mitosis). In Experiment 1, 37 university students watched either realistic or schematic visualizations. Students' subjective task demands ratings as well as…

  15. Visual cognition

    PubMed Central

    Cavanagh, Patrick

    2011-01-01

    Visual cognition, high-level vision, mid-level vision and top-down processing all refer to decision-based scene analyses that combine prior knowledge with retinal input to generate representations. The label “visual cognition” is little used at present, but research and experiments on mid- and high-level, inference-based vision have flourished, becoming in the 21st century a significant, if often understated part, of current vision research. How does visual cognition work? What are its moving parts? This paper reviews the origins and architecture of visual cognition and briefly describes some work in the areas of routines, attention, surfaces, objects, and events (motion, causality, and agency). Most vision scientists avoid being too explicit when presenting concepts about visual cognition, having learned that explicit models invite easy criticism. What we see in the literature is ample evidence for visual cognition, but few or only cautious attempts to detail how it might work. This is the great unfinished business of vision research: at some point we will be done with characterizing how the visual system measures the world and we will have to return to the question of how vision constructs models of objects, surfaces, scenes, and events. PMID:21329719

  16. Biochemical abnormalities in neonatal seizures.

    PubMed

    Sood, Arvind; Grover, Neelam; Sharma, Roshan

    2003-03-01

    The presence of seizure does not constitute a diagnoses but it is a symptom of an underlying central nervous system disorder due to systemic or biochemical disturbances. Biochemical disturbances occur frequently in the neonatal seizures either as an underlying cause or as an associated abnormality. In their presence, it is difficult to control seizure and there is a risk of further brain damage. Early recognition and treatment of biochemical disturbances is essential for optimal management and satisfactory long term outcome. The present study was conducted in the department of pediatrics in IGMC Shimla on 59 neonates. Biochemical abnormalities were detected in 29 (49.15%) of cases. Primary metabolic abnormalities occurred in 10(16.94%) cases of neonatal seizures, most common being hypocalcaemia followed by hypoglycemia, other metabolic abnormalities include hypomagnesaemia and hyponateremia. Biochemical abnormalities were seen in 19(38.77%) cases of non metabolic seizure in neonates. Associated metabolic abnormalities were observed more often with Hypoxic-ischemic-encephalopathy (11 out of 19) cases and hypoglycemia was most common in this group. No infant had hyponateremia, hyperkelemia or low zinc level.

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

    NASA Technical Reports Server (NTRS)

    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).

  18. Visual impairment in FOXG1-mutated individuals and mice.

    PubMed

    Boggio, E M; Pancrazi, L; Gennaro, M; Lo Rizzo, C; Mari, F; Meloni, I; Ariani, F; Panighini, A; Novelli, E; Biagioni, M; Strettoi, E; Hayek, J; Rufa, A; Pizzorusso, T; Renieri, A; Costa, M

    2016-06-02

    The Forkead Box G1 (FOXG1 in humans, Foxg1 in mice) gene encodes for a DNA-binding transcription factor, essential for the development of the telencephalon in mammalian forebrain. Mutations in FOXG1 have been reported to be involved in the onset of Rett Syndrome, for which sequence alterations of MECP2 and CDKL5 are known. While visual alterations are not classical hallmarks of Rett syndrome, an increasing body of evidence shows visual impairment in patients and in MeCP2 and CDKL5 animal models. Herein we focused on the functional role of FOXG1 in the visual system of animal models (Foxg1(+/Cre) mice) and of a cohort of subjects carrying FOXG1 mutations or deletions. Visual physiology of Foxg1(+/Cre) mice was assessed by visually evoked potentials, which revealed a significant reduction in response amplitude and visual acuity with respect to wild-type littermates. Morphological investigation showed abnormalities in the organization of excitatory/inhibitory circuits in the visual cortex. No alterations were observed in retinal structure. By examining a cohort of FOXG1-mutated individuals with a panel of neuro-ophthalmological assessments, we found that all of them exhibited visual alterations compatible with high-level visual dysfunctions. In conclusion our data show that Foxg1 haploinsufficiency results in an impairment of mouse and human visual cortical function. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  19. SeeDB: Efficient Data-Driven Visualization Recommendations to Support Visual Analytics

    PubMed Central

    Vartak, Manasi; Rahman, Sajjadur; Madden, Samuel; Parameswaran, Aditya; Polyzotis, Neoklis

    2015-01-01

    Data analysts often build visualizations as the first step in their analytical workflow. However, when working with high-dimensional datasets, identifying visualizations that show relevant or desired trends in data can be laborious. We propose SeeDB, a visualization recommendation engine to facilitate fast visual analysis: given a subset of data to be studied, SeeDB intelligently explores the space of visualizations, evaluates promising visualizations for trends, and recommends those it deems most “useful” or “interesting”. The two major obstacles in recommending interesting visualizations are (a) scale: evaluating a large number of candidate visualizations while responding within interactive time scales, and (b) utility: identifying an appropriate metric for assessing interestingness of visualizations. For the former, SeeDB introduces pruning optimizations to quickly identify high-utility visualizations and sharing optimizations to maximize sharing of computation across visualizations. For the latter, as a first step, we adopt a deviation-based metric for visualization utility, while indicating how we may be able to generalize it to other factors influencing utility. We implement SeeDB as a middleware layer that can run on top of any DBMS. Our experiments show that our framework can identify interesting visualizations with high accuracy. Our optimizations lead to multiple orders of magnitude speedup on relational row and column stores and provide recommendations at interactive time scales. Finally, we demonstrate via a user study the effectiveness of our deviation-based utility metric and the value of recommendations in supporting visual analytics. PMID:26779379

  20. SeeDB: Efficient Data-Driven Visualization Recommendations to Support Visual Analytics.

    PubMed

    Vartak, Manasi; Rahman, Sajjadur; Madden, Samuel; Parameswaran, Aditya; Polyzotis, Neoklis

    2015-09-01

    Data analysts often build visualizations as the first step in their analytical workflow. However, when working with high-dimensional datasets, identifying visualizations that show relevant or desired trends in data can be laborious. We propose SeeDB, a visualization recommendation engine to facilitate fast visual analysis: given a subset of data to be studied, SeeDB intelligently explores the space of visualizations, evaluates promising visualizations for trends, and recommends those it deems most "useful" or "interesting". The two major obstacles in recommending interesting visualizations are (a) scale : evaluating a large number of candidate visualizations while responding within interactive time scales, and (b) utility : identifying an appropriate metric for assessing interestingness of visualizations. For the former, SeeDB introduces pruning optimizations to quickly identify high-utility visualizations and sharing optimizations to maximize sharing of computation across visualizations. For the latter, as a first step, we adopt a deviation-based metric for visualization utility, while indicating how we may be able to generalize it to other factors influencing utility. We implement SeeDB as a middleware layer that can run on top of any DBMS. Our experiments show that our framework can identify interesting visualizations with high accuracy. Our optimizations lead to multiple orders of magnitude speedup on relational row and column stores and provide recommendations at interactive time scales. Finally, we demonstrate via a user study the effectiveness of our deviation-based utility metric and the value of recommendations in supporting visual analytics.

  1. Early visual experience and the recognition of basic facial expressions: involvement of the middle temporal and inferior frontal gyri during haptic identification by the early blind

    PubMed Central

    Kitada, Ryo; Okamoto, Yuko; Sasaki, Akihiro T.; Kochiyama, Takanori; Miyahara, Motohide; Lederman, Susan J.; Sadato, Norihiro

    2012-01-01

    Face perception is critical for social communication. Given its fundamental importance in the course of evolution, the innate neural mechanisms can anticipate the computations necessary for representing faces. However, the effect of visual deprivation on the formation of neural mechanisms that underlie face perception is largely unknown. We previously showed that sighted individuals can recognize basic facial expressions by haptics surprisingly well. Moreover, the inferior frontal gyrus (IFG) and posterior superior temporal sulcus (pSTS) in the sighted subjects are involved in haptic and visual recognition of facial expressions. Here, we conducted both psychophysical and functional magnetic-resonance imaging (fMRI) experiments to determine the nature of the neural representation that subserves the recognition of basic facial expressions in early blind individuals. In a psychophysical experiment, both early blind and sighted subjects haptically identified basic facial expressions at levels well above chance. In the subsequent fMRI experiment, both groups haptically identified facial expressions and shoe types (control). The sighted subjects then completed the same task visually. Within brain regions activated by the visual and haptic identification of facial expressions (relative to that of shoes) in the sighted group, corresponding haptic identification in the early blind activated regions in the inferior frontal and middle temporal gyri. These results suggest that the neural system that underlies the recognition of basic facial expressions develops supramodally even in the absence of early visual experience. PMID:23372547

  2. Disentangling How the Brain is "Wired" in Cortical (Cerebral) Visual Impairment.

    PubMed

    Merabet, Lotfi B; Mayer, D Luisa; Bauer, Corinna M; Wright, Darick; Kran, Barry S

    2017-05-01

    Cortical (cerebral) visual impairment (CVI) results from perinatal injury to visual processing structures and pathways of the brain and is the most common cause of severe visual impairment or blindness in children in developed countries. Children with CVI display a wide range of visual deficits including decreased visual acuity, impaired visual field function, as well as impairments in higher-order visual processing and attention. Together, these visual impairments can dramatically influence a child's development and well-being. Given the complex neurologic underpinnings of this condition, CVI is often undiagnosed by eye care practitioners. Furthermore, the neurophysiological basis of CVI in relation to observed visual processing deficits remains poorly understood. Here, we present some of the challenges associated with the clinical assessment and management of individuals with CVI. We discuss how advances in brain imaging are likely to help uncover the underlying neurophysiology of this condition. In particular, we demonstrate how structural and functional neuroimaging approaches can help gain insight into abnormalities of white matter connectivity and cortical activation patterns, respectively. Establishing a connection between how changes within the brain relate to visual impairments in CVI will be important for developing effective rehabilitative and education strategies for individuals living with this condition. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Ophthalmologic abnormalities among students with cognitive impairment in eastern Taiwan: The special group with undetected visual impairment.

    PubMed

    Tsao, Wei-Shan; Hsieh, Hsi-Pao; Chuang, Yi-Ting; Sheu, Min-Muh

    2017-05-01

    Students with cognitive impairment are at increased risk of suffering from visual impairment due to refractive errors and ocular disease, which can adversely influence learning and daily activities. The purpose of this study was to evaluate the ocular and visual status among students at the special education school in Hualien. All students at the National Hualien Special Education School were evaluated. Full eye examinations were conducted by a skilled ophthalmologist. The students' medical records and disability types were reviewed. A total of 241 students, aged 7-18 years, were examined. Visual acuity could be assessed in 138 students. A total of 169/477 (35.4%) eyes were found to suffer from refractive errors, including 20 eyes with high myopia (≤-6.0 D) and 16 eyes with moderate hypermetropia (+3.0 D to +5.0 D). A total of 84/241 (34.8%) students needed spectacles to correct their vision, thus improving their daily activities and learning process, but only 15/241 (6.2%) students were wearing suitable corrective spectacles. A total of 55/241 students (22.8%) had ocular disorders, which influenced their visual function. The multiple disability group had a statistically significant higher prevalence of ocular disorders (32.9%) than the simple intellectual disability group (19.6%). Students with cognitive impairment in eastern Taiwan have a high risk of visual impairment due to refractive errors and ocular disorders. Importantly, many students have unrecognized correctable refractive errors. Regular ophthalmic examination should be administered to address this issue and prevent further disability in this already handicapped group. Copyright © 2016. Published by Elsevier B.V.

  4. Ipsilateral visual illusion after unilateral posterior cerebral artery infarction: a report of two cases.

    PubMed

    Hong, Yoon Hee; Lim, Tae-Sung; Yong, Suk Woo; Moon, So Young

    2010-08-15

    In cases of unilateral posterior cerebral artery (PCA) infarction, abnormal visual perception in the ipsilateral visual field, which is usually believed to be intact, is not met frequently and may confuse doctors during evaluation. Recently, we observed two patients who presented with contralateral hemianopsia accompanied by ipsilateral visual illusions after acute unilateral PCA infarctions. Their visual illusion was characterized by zooming in, macropsia or micropsia. These symptoms appeared to be related to deficits in size constancy. Lesions of both patients commonly involved the ipsilateral forceps major. The consistent presentation observed in these two patients suggests that dominance of size constancy can be located in the left hemisphere in some individuals. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  5. Visual short-term memory guides infants' visual attention.

    PubMed

    Mitsven, Samantha G; Cantrell, Lisa M; Luck, Steven J; Oakes, Lisa M

    2018-08-01

    Adults' visual attention is guided by the contents of visual short-term memory (VSTM). Here we asked whether 10-month-old infants' (N = 41) visual attention is also guided by the information stored in VSTM. In two experiments, we modified the one-shot change detection task (Oakes, Baumgartner, Barrett, Messenger, & Luck, 2013) to create a simplified cued visual search task to ask how information stored in VSTM influences where infants look. A single sample item (e.g., a colored circle) was presented at fixation for 500 ms, followed by a brief (300 ms) retention interval and then a test array consisting of two items, one on each side of fixation. One item in the test array matched the sample stimulus and the other did not. Infants were more likely to look at the non-matching item than at the matching item, demonstrating that the information stored rapidly in VSTM guided subsequent looking behavior. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Self-consciousness of disproportionate breast size: a primary psychological reaction to abnormal appearance.

    PubMed

    Harris, D L

    1983-04-01

    An hypothesis is proposed to answer two questions: "How do the symptoms that are the experience of subjects who are self-conscious of abnormal appearance develop?" and "Why do they develop in some people and not others?" The hypothesis is explained using the typical experiences of patients with disproportionate breast size as examples.

  7. Centrifuge in space fluid flow visualization experiment

    NASA Technical Reports Server (NTRS)

    Arnold, William A.; Wilcox, William R.; Regel, Liya L.; Dunbar, Bonnie J.

    1993-01-01

    A prototype flow visualization system is constructed to examine buoyancy driven flows during centrifugation in space. An axial density gradient is formed by imposing a thermal gradient between the two ends of the test cell. Numerical computations for this geometry showed that the Prandtl number plays a limited part in determining the flow.

  8. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy.

    PubMed

    Shakespeare, Timothy J; Kaski, Diego; Yong, Keir X X; Paterson, Ross W; Slattery, Catherine F; Ryan, Natalie S; Schott, Jonathan M; Crutch, Sebastian J

    2015-07-01

    The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal 'visual dementia' and most common atypical Alzheimer's disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation and basic visual phenomena (e.g. visual crowding). Given the extensive attention paid to patients' (higher order) perceptual function, it is surprising that there have been no systematic analyses of basic oculomotor function in this population. Here 20 patients with posterior cortical atrophy, 17 patients with typical Alzheimer's disease and 22 healthy controls completed tests of fixation, saccade (including fixation/target gap and overlap conditions) and smooth pursuit eye movements using an infrared pupil-tracking system. Participants underwent detailed neuropsychological and neurological examinations, with a proportion also undertaking brain imaging and analysis of molecular pathology. In contrast to informal clinical evaluations of oculomotor dysfunction frequency (previous studies: 38%, current clinical examination: 33%), detailed eyetracking investigations revealed eye movement abnormalities in 80% of patients with posterior cortical atrophy (compared to 17% typical Alzheimer's disease, 5% controls). The greatest differences between posterior cortical atrophy and typical Alzheimer's disease were seen in saccadic performance. Patients with posterior cortical atrophy made significantly shorter saccades especially for distant targets. They also exhibited a significant exacerbation of the normal gap/overlap effect, consistent with 'sticky fixation'. Time to reach saccadic targets was significantly associated with parietal and occipital cortical thickness measures. On fixation stability tasks, patients with typical Alzheimer's disease showed more square wave jerks whose frequency was associated with lower cerebellar grey matter volume, while patients with posterior cortical atrophy showed large saccadic intrusions

  9. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy

    PubMed Central

    Kaski, Diego; Yong, Keir X. X.; Paterson, Ross W.; Slattery, Catherine F.; Ryan, Natalie S.; Schott, Jonathan M.; Crutch, Sebastian J.

    2015-01-01

    The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal ‘visual dementia’ and most common atypical Alzheimer’s disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation and basic visual phenomena (e.g. visual crowding). Given the extensive attention paid to patients’ (higher order) perceptual function, it is surprising that there have been no systematic analyses of basic oculomotor function in this population. Here 20 patients with posterior cortical atrophy, 17 patients with typical Alzheimer’s disease and 22 healthy controls completed tests of fixation, saccade (including fixation/target gap and overlap conditions) and smooth pursuit eye movements using an infrared pupil-tracking system. Participants underwent detailed neuropsychological and neurological examinations, with a proportion also undertaking brain imaging and analysis of molecular pathology. In contrast to informal clinical evaluations of oculomotor dysfunction frequency (previous studies: 38%, current clinical examination: 33%), detailed eyetracking investigations revealed eye movement abnormalities in 80% of patients with posterior cortical atrophy (compared to 17% typical Alzheimer’s disease, 5% controls). The greatest differences between posterior cortical atrophy and typical Alzheimer’s disease were seen in saccadic performance. Patients with posterior cortical atrophy made significantly shorter saccades especially for distant targets. They also exhibited a significant exacerbation of the normal gap/overlap effect, consistent with ‘sticky fixation’. Time to reach saccadic targets was significantly associated with parietal and occipital cortical thickness measures. On fixation stability tasks, patients with typical Alzheimer’s disease showed more square wave jerks whose frequency was associated with lower cerebellar grey matter volume, while patients with posterior cortical atrophy showed large

  10. Chorionic villus sampling for abnormal screening compared to historical indications: prevalence of abnormal karyotypes.

    PubMed

    Marshall, Nicole E; Fraley, Gwen; Feist, Cori; Burns, Michael J; Pereira, Leonardo

    2012-08-01

    To determine the prevalence of abnormal karyotype results in women undergoing chorionic villus sampling (CVS) for abnormal first trimester screening compared to CVS for historical indications (advanced maternal age (AMA) or prior aneuploidy). Retrospective cohort of all patients undergoing CVS at Oregon Health & Science University from January 2006 to June 2010. Patients were separated based on CVS indication: (1) positive ultrasound (U/S) or serum screening; or (2) AMA or prior aneuploidy with normal or no screening. Prevalence of abnormal karyotype results were compared between groups. Fetal karyotyping was successful in 500 of 506 CVS procedures performed. 203 CVS were performed for positive screening with 69 abnormal karyotypes (34.0%). 264 CVS were performed for historical indications with 11 abnormal karyotypes (4.2%). This difference was statistically significant (χ(2) 71.9, p < 0.001; OR 11.8 [95% CI 5.8, 24.6]). There were two age-related aneuplodies in AMA women without positive screening. 42 out of 44 AMA women diagnosed with aneuploidy (95.5%) had abnormal U/S and/or serum screening (35 U/S, 4 serum, 3 U/S and serum). Combined ultrasound and serum screening should be recommended to all women, including AMA women, prior to undergoing invasive testing to improve risk-based counseling and minimize morbidity.

  11. Visual function among commercial vehicle drivers in the central region of Ghana

    PubMed Central

    Boadi-Kusi, Samuel Bert; Kyei, Samuel; Asare, Frederick Afum; Owusu-Ansah, Andrew; Awuah, Agnes; Darko-Takyi, Charles

    2015-01-01

    Aim To determine the relationship between some visual functions: colour vision defects, abnormal stereopsis, visual acuity and the occurrence of road traffic accident (RTAs) among commercial vehicle drivers in the central region of Ghana, and to assess their knowledge of these anomalies. Method A descriptive cross-sectional study employing a multi-stage random sampling approach was conducted in the major commercial towns within the central region of Ghana. Participants were taken through a comprehensive eye examination after the administration of a structured questionnaire. Results 520 male commercial vehicle drivers were enrolled for this study with a mean age of 39.23 years ±10.96 years and mean visual acuity of 0.02 ± 0.08 logMAR. Protans were more likely to be involved in RTAs (χ2 = 6.194, p = 0.034). However, there was no statistically significant association between abnormal stereopsis (OR = 0.89 95% CI: 0.44–1.80, p = 0.56), poor vision due to refractive error (χ2 = 3.090, p = 0.388) and the occurrence of RTAs. While 86.9% were aware of abnormal stereopsis, only 45% were aware of colour vision defects. There was a statistically significant association between stereopsis anomaly and colour vision defect (r = 0.371, p < 0.005). Conclusion The study found an association between protanopia and RTAs but none between stereopsis anomalies, refractive errors and the occurrence of RTAs. Drivers were less knowledgeable on colour vision defects as compared to stereopsis anomalies. PMID:26364760

  12. Controlling the spotlight of attention: visual span size and flexibility in schizophrenia.

    PubMed

    Elahipanah, Ava; Christensen, Bruce K; Reingold, Eyal M

    2011-10-01

    The current study investigated the size and flexible control of visual span among patients with schizophrenia during visual search performance. Visual span is the region of the visual field from which one extracts information during a single eye fixation, and a larger visual span size is linked to more efficient search performance. Therefore, a reduced visual span may explain patients' impaired performance on search tasks. The gaze-contingent moving window paradigm was used to estimate the visual span size of patients and healthy participants while they performed two different search tasks. In addition, changes in visual span size were measured as a function of two manipulations of task difficulty: target-distractor similarity and stimulus familiarity. Patients with schizophrenia searched more slowly across both tasks and conditions. Patients also demonstrated smaller visual span sizes on the easier search condition in each task. Moreover, healthy controls' visual span size increased as target discriminability or distractor familiarity increased. This modulation of visual span size, however, was reduced or not observed among patients. The implications of the present findings, with regard to previously reported visual search deficits, and other functional and structural abnormalities associated with schizophrenia, are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Experiences of Visually Impaired Students in Community College Math Courses

    ERIC Educational Resources Information Center

    Swan, S. Tomeka

    2017-01-01

    Blind and visually impaired students who attend community colleges face challenges in learning mathematics (Forrest, 2010). Scoy, McLaughlin, Walls, and Zuppuhaur (2006) claim these students are at a disadvantage in studying mathematics due to the visual and interactive nature of the subject, and by the way mathematics is taught. In this…

  14. Abnormal functional connectivity density in children with anisometropic amblyopia at resting-state.

    PubMed

    Wang, Tianyue; Li, Qian; Guo, Mingxia; Peng, Yanmin; Li, Qingji; Qin, Wen; Yu, Chunshui

    2014-05-14

    Amblyopia is a developmental disorder resulting from anomalous binocular visual input in early life. Task-based neuroimaging studies have widely investigated cortical functional impairments in amblyopia, but changes in spontaneous neuronal functional activities in amblyopia remain largely unknown. In the present study, functional connectivity density (FCD) mapping, an ultrafast data-driven method based on fMRI, was applied for the first time to investigate changes in cortical functional connectivities in amblyopia during the resting-state. We quantified and compared both short- and long-range FCD in both the brains of children with anisometropic amblyopia (AAC) and normal sighted children (NSC). In contrast to the NSC, the AAC showed significantly decreased short-range FCD in the inferior temporal/fusiform gyri, parieto-occipital and rostrolateral prefrontal cortices, as well as decreased long-range FCD in the premotor cortex, dorsal inferior parietal lobule, frontal-insular and dorsal prefrontal cortices. Furthermore, most regions with reduced long-range FCD in the AAC showed decreased functional connectivity with occipital and posterior parietal cortices in the AAC. The results suggest that chronically poor visual input in amblyopia not only impairs the brain's short-range functional connections in visual pathways and in the frontal cortex, which is important for cognitive control, but also affects long-range functional connections among the visual areas, posterior parietal and frontal cortices that subserve visuomotor and visual-guided actions, visuospatial attention modulation and the integration of salient information. This study provides evidence for abnormal spontaneous brain activities in amblyopia. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Representation of the visual field in the striate cortex: comparison of MR findings with visual field deficits in organic mercury poisoning (Minamata disease).

    PubMed

    Korogi, Y; Takahashi, M; Hirai, T; Ikushima, I; Kitajima, M; Sugahara, T; Shigematsu, Y; Okajima, T; Mukuno, K

    1997-01-01

    To compare MR imaging findings of the striate cortex with visual field deficits in patients with Minamata disease and to reestimate the classical Holmes retinotopic map by using the data obtained from comparing visual field abnormalities with degree of visual cortex atrophy. MR imaging was performed in eight patients with Minamata disease who had been given a full neuroophthalmic examination, including Goldmann dynamic perimetry. The atrophic portions of the calcarine area were measured in the sagittal plane next to the midsagittal image and represented as a percentage of atrophy of the total length of the calcarine fissure. MR findings were compared with results of a visual field test. The visual field test revealed moderate to severe concentric constriction of the visual fields, with central vision ranging from 7 degrees to 42 degrees (mean, 19 degrees). The ventral portion of the calcarine sulcus was significantly dilated on MR images in all patients. A logarithmic correlation was found between the visual field defect and the extent of dilatation of the calcarine fissure. The central 10 degrees and 30 degrees of vision seemed to fill about 20% and 50% of the total surface area of the calcarine cortex, respectively. Visual field deficits in patients with Minamata disease correlated well with MR findings of the striate cortex. Our data were consistent with the classical Holmes retinotopic map.

  16. Development of Abnormality Detection System for Bathers using Ultrasonic Sensors

    NASA Astrophysics Data System (ADS)

    Ohnishi, Yosuke; Abe, Takehiko; Nambo, Hidetaka; Kimura, Haruhiko; Ogoshi, Yasuhiro

    This paper proposes an abnormality detection system for bather sitting in bathtub. Increasing number of in-bathtub drowning accidents in Japan draws attention. Behind this large number of bathing accidents, Japan's unique social and cultural background come surface. For majority of people in Japan, bathing serves purpose in deep warming up of body, relax and enjoyable time. Therefore it is the custom for the Japanese to soak in bathtub. However overexposure to hot water may cause dizziness or fainting, which is possible to cause in-bathtub drowning. For drowning prevention, the system detects bather's abnormal state using an ultrasonic sensor array. The array, which has many ultrasonic sensors, is installed on the ceiling of bathroom above bathtub. The abnormality detection system uses the following two methods: posture detection and behavior detection. The function of posture detection is to estimate the risk of drowning by monitoring bather's posture. Meanwhile, the function of behavior detection is to estimate the risk of drowning by monitoring bather's behavior. By using these methods, the system detects bathers' different state from normal. As a result of experiment with a subject in the bathtub, the system was possible to detect abnormal state using subject's posture and behavior. Therefore the system is useful for monitoring bather to prevent drowning in bathtub.

  17. Experience improves feature extraction in Drosophila.

    PubMed

    Peng, Yueqing; Xi, Wang; Zhang, Wei; Zhang, Ke; Guo, Aike

    2007-05-09

    Previous exposure to a pattern in the visual scene can enhance subsequent recognition of that pattern in many species from honeybees to humans. However, whether previous experience with a visual feature of an object, such as color or shape, can also facilitate later recognition of that particular feature from multiple visual features is largely unknown. Visual feature extraction is the ability to select the key component from multiple visual features. Using a visual flight simulator, we designed a novel protocol for visual feature extraction to investigate the effects of previous experience on visual reinforcement learning in Drosophila. We found that, after conditioning with a visual feature of objects among combinatorial shape-color features, wild-type flies exhibited poor ability to extract the correct visual feature. However, the ability for visual feature extraction was greatly enhanced in flies trained previously with that visual feature alone. Moreover, we demonstrated that flies might possess the ability to extract the abstract category of "shape" but not a particular shape. Finally, this experience-dependent feature extraction is absent in flies with defective MBs, one of the central brain structures in Drosophila. Our results indicate that previous experience can enhance visual feature extraction in Drosophila and that MBs are required for this experience-dependent visual cognition.

  18. Language experience shapes early electrophysiological responses to visual stimuli: the effects of writing system, stimulus length, and presentation duration.

    PubMed

    Xue, Gui; Jiang, Ting; Chen, Chuansheng; Dong, Qi

    2008-02-15

    How language experience affects visual word recognition has been a topic of intense interest. Using event-related potentials (ERPs), the present study compared the early electrophysiological responses (i.e., N1) to familiar and unfamiliar writings under different conditions. Thirteen native Chinese speakers (with English as their second language) were recruited to passively view four types of scripts: Chinese (familiar logographic writings), English (familiar alphabetic writings), Korean Hangul (unfamiliar logographic writings), and Tibetan (unfamiliar alphabetic writings). Stimuli also differed in lexicality (words vs. non-words, for familiar writings only), length (characters/letters vs. words), and presentation duration (100 ms vs. 750 ms). We found no significant differences between words and non-words, and the effect of language experience (familiar vs. unfamiliar) was significantly modulated by stimulus length and writing system, and to a less degree, by presentation duration. That is, the language experience effect (i.e., a stronger N1 response to familiar writings than to unfamiliar writings) was significant only for alphabetic letters, but not for alphabetic and logographic words. The difference between Chinese characters and unfamiliar logographic characters was significant under the condition of short presentation duration, but not under the condition of long presentation duration. Long stimuli elicited a stronger N1 response than did short stimuli, but this effect was significantly attenuated for familiar writings. These results suggest that N1 response might not reliably differentiate familiar and unfamiliar writings. More importantly, our results suggest that N1 is modulated by visual, linguistic, and task factors, which has important implications for the visual expertise hypothesis.

  19. Temporal properties of material categorization and material rating: visual vs non-visual material features.

    PubMed

    Nagai, Takehiro; Matsushima, Toshiki; Koida, Kowa; Tani, Yusuke; Kitazaki, Michiteru; Nakauchi, Shigeki

    2015-10-01

    Humans can visually recognize material categories of objects, such as glass, stone, and plastic, easily. However, little is known about the kinds of surface quality features that contribute to such material class recognition. In this paper, we examine the relationship between perceptual surface features and material category discrimination performance for pictures of materials, focusing on temporal aspects, including reaction time and effects of stimulus duration. The stimuli were pictures of objects with an identical shape but made of different materials that could be categorized into seven classes (glass, plastic, metal, stone, wood, leather, and fabric). In a pre-experiment, observers rated the pictures on nine surface features, including visual (e.g., glossiness and transparency) and non-visual features (e.g., heaviness and warmness), on a 7-point scale. In the main experiments, observers judged whether two simultaneously presented pictures were classified as the same or different material category. Reaction times and effects of stimulus duration were measured. The results showed that visual feature ratings were correlated with material discrimination performance for short reaction times or short stimulus durations, while non-visual feature ratings were correlated only with performance for long reaction times or long stimulus durations. These results suggest that the mechanisms underlying visual and non-visual feature processing may differ in terms of processing time, although the cause is unclear. Visual surface features may mainly contribute to material recognition in daily life, while non-visual features may contribute only weakly, if at all. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Multidimensional analysis of the abnormal neural oscillations associated with lexical processing in schizophrenia.

    PubMed

    Xu, Tingting; Stephane, Massoud; Parhi, Keshab K

    2013-04-01

    The neural mechanisms of language abnormalities, the core symptoms in schizophrenia, remain unclear. In this study, a new experimental paradigm, combining magnetoencephalography (MEG) techniques and machine intelligence methodologies, was designed to gain knowledge about the frequency, brain location, and time of occurrence of the neural oscillations that are associated with lexical processing in schizophrenia. The 248-channel MEG recordings were obtained from 12 patients with schizophrenia and 10 healthy controls, during a lexical processing task, where the patients discriminated correct from incorrect lexical stimuli that were visually presented. Event-related desynchronization/synchronization (ERD/ERS) was computed along the frequency, time, and space dimensions combined, that resulted in a large spectral-spatial-temporal ERD/ERS feature set. Machine intelligence techniques were then applied to select a small subset of oscillation patterns that are abnormal in patients with schizophrenia, according to their discriminating power in patient and control classification. Patients with schizophrenia showed abnormal ERD/ERS patterns during both lexical encoding and post-encoding periods. The top-ranked features were located at the occipital and left frontal-temporal areas, and covered a wide frequency range, including δ (1-4 Hz), α (8-12 Hz), β (12-32 Hz), and γ (32-48 Hz) bands. These top features could discriminate the patient group from the control group with 90.91% high accuracy, which demonstrates significant brain oscillation abnormalities in patients with schizophrenia at the specific frequency, time, and brain location indicated by these top features. As neural oscillation abnormality may be due to the mechanisms of the disease, the spectral, spatial, and temporal content of the discriminating features can offer useful information for helping understand the physiological basis of the language disorder in schizophrenia, as well as the pathology of the