Science.gov

Sample records for abnormal visual experience

  1. Abnormal visual experience during development alters the early stages of visual-tactile integration.

    PubMed

    Niechwiej-Szwedo, Ewa; Chin, Jessica; Wolfe, Paul J; Popovich, Christina; Staines, W Richard

    2016-05-01

    Visual experience during the critical periods in early postnatal life is necessary for the normal development of the visual system. Disruption of visual input during this period results in amblyopia, which is associated with reduced activation of the striate and extrastriate cortices. It is well known that visual input converges with other sensory signals and exerts a significant influence on cortical processing in multiple association areas. Recent work in healthy adults has also shown that task-relevant visual input can modulate neural excitability at very early stages of information processing in the primary somatosensory cortex. Here we used electroencephalography to investigate visual-tactile interactions in adults with abnormal binocular vision due to amblyopia and strabismus. Results showed three main findings. First, in comparison to a visually normal control group, participants with abnormal vision had a significantly lower amplitude of the P50 somatosensory event related potential (ERP) when visual and tactile stimuli were presented concurrently. Second, the amplitude of the P100 somatosensory ERP was significantly greater in participants with abnormal vision. These results indicate that task relevant visual input does not significantly influence the excitability of the primary somatosensory cortex, instead, the excitability of the secondary somatosensory cortex is increased. Third, participants with abnormal vision had a higher amplitude of the P1 visual ERP when a tactile stimulus was presented concurrently. Importantly, these results were not modulated by viewing condition, which indicates that the impact of amblyopia on crossmodal interactions is not simply related to the reduced visual acuity as it was evident when viewing with the unaffected eye and binocularly. These results indicate that the consequences of abnormal visual experience on neurophysiological processing extend beyond the primary and secondary visual areas to other modality

  2. Electrophysiological Evidence that Abnormal Early Visual Experience Can Modify the Human Brain.

    PubMed

    Freeman, R D; Thibos, L N

    1973-06-15

    In the caption of the cover photograph for 25 May 1973, the word "below" is misplaced; it should be deleted from the first sentence, and the second sentence should read: "(Below) Same view taken through a cylindrical lens . . ." Two errors occurred in the report by Freeman and Thibos in the same issue, p. 876: in column 2, line 4, "Freeman and co-workers" should be changed to "Freeman et al." in column 3, line 44, "the visual resolution" should be changed to "visual resolution"-Ed. PMID:17743606

  3. Effects of Normal and Abnormal Visual Experience on the Development of Opposing Aftereffects for Upright and Inverted Faces

    ERIC Educational Resources Information Center

    Robbins, Rachel A.; Maurer, Daphne; Hatry, Alexandra; Anzures, Gizelle; Mondloch, Catherine J.

    2012-01-01

    We used opposing figural aftereffects to investigate whether there are at least partially separable representations of upright and inverted faces in patients who missed early visual experience because of bilateral congenital cataracts (mean age at test 19.5 years). Visually normal adults and 10-year-olds were tested for comparison. Adults showed…

  4. Visual Experiences during Paralysis

    PubMed Central

    Whitham, Emma M.; Fitzgibbon, Sean P.; Lewis, Trent W.; Pope, Kenneth J.; DeLosAngeles, Dylan; Clark, C. Richard; Lillie, Peter; Hardy, Andrew; Gandevia, Simon C.; Willoughby, John O.

    2011-01-01

    Rationale: Paralyzed human volunteers (n = 6) participated in several studies the primary one of which required full neuromuscular paralysis while awake. After the primary experiment, while still paralyzed and awake, subjects undertook studies of humor and of attempted eye-movement. The attempted eye-movements tested a central, intentional component to one’s internal visual model and are the subject of this report. Methods: Subjects reclined in a supportive chair and were ventilated after paralysis (cisatracurium, 20 mg intravenously). In illumination, subjects were requested to focus alternately on the faces of investigators standing on the left and the right within peripheral vision. In darkness, subjects were instructed to look away from a point source of light. Subjects were to report their experiences after reversal of paralysis. Results: During attempted eye-movement in illumination, one subject had an illusion of environmental movement but four subjects perceived faces as clearly as if they were in central vision. In darkness, four subjects reported movement of the target light in the direction of attempted eye-movements and three could control the movement of the light at will. Conclusion: The hypothesis that internal visual models receive intended ocular-movement-information directly from oculomotor centers is strengthened by this evidence. PMID:22162967

  5. Reversible visual evoked potential abnormalities in uremic children.

    PubMed

    Ethier, Audrey-Anne; Lippé, Sarah; Mérouani, Aicha; Lassonde, Maryse; Saint-Amour, Dave

    2012-06-01

    In this case study, two cystinosis-related uremic children were followed at the Department of Nephrology, University of Montreal Hospital Center Sainte-Justine. Pattern-reversal visual evoked potentials were recorded at two time points, during dialysis treatment (time 1) and after renal transplant (time 2). Data were compared with those obtained from a control group (n = 6). The P1 component was selected and analyzed as the electrophysiologic marker of interest. At time 1, P1 latency was delayed, and P1 amplitude was reduced compared with control subjects. Both responses fell within normal range after kidney transplantation. These results indicate that renal failure and dialysis are associated with abnormal visual evoked potentials in children with chronic renal failure, but such alterations of visual processing are reversible after kidney transplant. PMID:22633636

  6. 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. PMID:26412383

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

    PubMed Central

    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. PMID:27152128

  8. 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. PMID:27152128

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

    Beilharz, Francesca L; Atkins, Kelly J; Duncum, Anna J F; Mundy, Matthew E

    2016-01-01

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

  11. Abnormalities in visual processing amongst students with body image concerns

    PubMed Central

    Mundy E., Matthew; Sadusky, Andrea

    2014-01-01

    Individuals with body dysmorphic disorder (BDD) appear to possess abnormalities in the way they observe and discriminate visual information. A pre-occupation with perceived defects in appearance has been attributed to a local visual processing bias. We studied the nature of visual bias in individuals who may be at risk of developing BDD – those with high body image concerns (BICs) – by using inverted stimulus discrimination. Inversion disrupts global, configural information in favor of local, feature-based processing. 40 individuals with high BIC and 40 low BIC controls performed a discrimination task with upright and inverted faces, bodies, and scenes. Individuals with high BIC discriminated inverted faces and bodies faster than controls, and were also more accurate when discriminating inverted bodies and scenes. This reduction in inversion effect for high BIC individuals may be due to a stimulus-general local, detail-focused processing bias, which may be associated with maladaptive fixation on small features in their appearance. PMID:25157299

  12. 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

  13. 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. PMID:20155554

  14. Abnormal visual gain control in a Parkinson's disease model

    PubMed Central

    Afsari, Farinaz; Christensen, Kenneth V.; Smith, Garrick Paul; Hentzer, Morten; Nippe, Olivia M.; Elliott, Christopher J. H.; Wade, Alex R.

    2014-01-01

    Our understanding of Parkinson's disease (PD) has been revolutionized by the discovery of disease-causing genetic mutations. The most common of these is the G2019S mutation in the LRRK2 kinase gene, which leads to increased kinase activity. However, the link between increased kinase activity and PD is unclear. Previously, we showed that dopaminergic expression of the human LRRK2-G2019S transgene in flies led to an activity-dependent loss of vision in older animals and we hypothesized that this may have been preceded by a failure to regulate neuronal activity correctly in younger animals. To test this hypothesis, we used a sensitive measure of visual function based on frequency-tagged steady-state visually evoked potentials. Spectral analysis allowed us to identify signals from multiple levels of the fly visual system and wild-type visual response curves were qualitatively similar to those from human cortex. Dopaminergic expression of hLRRK2-G2019S increased contrast sensitivity throughout the retinal network. To test whether this was due to increased kinase activity, we fed Drosophila with kinase inhibitors targeted at LRRK2. Contrast sensitivity in both day 1 and day 14 flies was normalized by a novel LRRK2 kinase inhibitor ‘BMPPB-32’. Biochemical and cellular assays suggested that BMPPB-32 would be a more specific kinase inhibitor than LRRK2-IN-1. We confirmed this in vivo, finding that dLRRK− null flies show large off-target effects with LRRK2-IN-1 but not BMPPB-32. Our data link the increased Kinase activity of the G2019S-LRRK2 mutation to neuronal dysfunction and demonstrate the power of the Drosophila visual system in assaying the neurological effects of genetic diseases and therapies. PMID:24718285

  15. Abnormal visual field maps in human cortex: a mini-review and a case report.

    PubMed

    Haak, Koen V; Langers, Dave R M; Renken, Remco; van Dijk, Pim; Borgstein, Johannes; Cornelissen, Frans W

    2014-07-01

    Human visual cortex contains maps of the visual field. Much research has been dedicated to answering whether and when these visual field maps change if critical components of the visual circuitry are damaged. Here, we first provide a focused mini-review of the functional magnetic resonance imaging (fMRI) studies that have evaluated the human cortical visual field maps in the face of retinal lesions, brain injury, and atypical retinocortical projections. We find that there is a fair body of research that has found abnormal fMRI activity, but also that this abnormal activity does not necessarily stem from cortical remapping. The abnormal fMRI activity can often be explained in terms of task effects and/or the uncovering of normally hidden system dynamics. We then present the case of a 16-year-old patient who lost the entire left cerebral hemisphere at age three for treatment of chronic focal encephalitis (Rasmussen syndrome) and intractable epilepsy. Using an fMRI retinotopic mapping procedure and population receptive field (pRF) modeling, we found that (1) despite the long period since the hemispherectomy, the retinotopic organization of early visual cortex remained unaffected by the removal of an entire cerebral hemisphere, and (2) the intact lateral occipital cortex contained an exceptionally large representation of the center of the visual field. The same method also indicates that the neuronal receptive fields in these lateral occipital brain regions are extraordinarily small. These features are clearly abnormal, but again they do not necessarily stem from cortical remapping. For example, the abnormal features can also be explained by the notion that the hemispherectomy took place during a critical period in the development of the lateral occipital cortex and therefore arrested its normal development. Thus, caution should be exercised when interpreting abnormal fMRI activity as a marker of cortical remapping; there are often other explanations. PMID:23347557

  16. 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

  17. 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.

  18. Macaque monkeys experience visual crowding

    PubMed Central

    Crowder, Erin A.; Olson, Carl R.

    2015-01-01

    In peripheral vision, objects that are easily discriminated on their own become less discriminable in the presence of surrounding clutter. This phenomenon is known as crowding.The neural mechanisms underlying crowding are not well understood. Better insight might come from single-neuron recording in nonhuman primates, provided they exhibit crowding; however, previous demonstrations of crowding have been confined to humans. In the present study, we set out to determine whether crowding occurs in rhesus macaque monkeys. We found that animals trained to identify a target letter among flankers displayed three hallmarks of crowding as established in humans. First, at a given eccentricity, increasing the spacing between the target and the flankers improved recognition accuracy. Second, the critical spacing, defined as the minimal spacing at which target discrimination was reliable, was proportional to eccentricity. Third, the critical spacing was largely unaffected by object size. We conclude that monkeys, like humans, experience crowding. These findings open the door to studies of crowding at the neuronal level in the monkey visual system. PMID:26067532

  19. Anorexia Nervosa and Body Dysmorphic Disorder are Associated with Abnormalities in Processing Visual Information

    PubMed Central

    Li, Wei; Lai, Tsz Man; Bohon, Cara; Loo, Sandra K; McCurdy, Danyale; Strober, Michael; Bookheimer, Susan; Feusner, Jamie

    2016-01-01

    Background Anorexia nervosa (AN) and body dysmorphic disorder (BDD) are characterized by distorted body image and are frequently comorbid 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 (ERP) and fMRI – to test for abnormal activity associated with early visual signaling. Methods 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. Results 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. Conclusions Results provide preliminary evidence of similar abnormal spatio-temporal activation in AN and BDD for configural/holistic information for appearance- and nonappearance-related stimuli. This suggests a common phenotype of abnormal early visual system functioning, which may contribute to perceptual distortions. PMID:25652023

  20. Abnormal bodily experiences may be a marker of early schizophrenia?

    PubMed

    Stanghellini, Giovanni; Ballerini, Massimo; Fusar Poli, Paolo; Cutting, John

    2012-01-01

    The purpose of this study is to answer the following question: What are the typical features of abnormal bodily experiences (ABEs) in persons affected by acute first-episode schizophrenia? Our overall objective is to contribute to enhance early diagnosis of schizophrenia, and providing supplementary diagnostic criteria especially for ultra-high risk patients. In a group of 39 patients with first-episode schizophrenia selected from a sample of 393 psychotic patients, 30 (76.9 %) reported ABEs. By means of a phenomenologically-based qualitative method of inquiry, we recognized four subtypes of ABEs whose main characteristics are dynamization of bodily boundaries and construction, morbid objectivization/devitalization, dysmorphic experiences and pain-like experiences. These four typologies of ABEs are documented through the patients' first-person self-descriptions, and then operationally defined. Two main properties emerge as tentative eidetic (defining) cores of ABEs in early schizophrenia: dynamization of bodily boundaries and construction, and morbid objectivization/devitalization. Sharpening the diagnostic sensibility for typically schizophrenic ABEs can help improve differential diagnosis between schizophrenia and other disorders entailing other types of anomalies of lived corporeality. Also, studying possible transitions from schizophrenic cenesthopathies to bodily delusions in persons with schizophrenia may refine the concept of bizarre delusions by improving its validity. Furthermore, our knowledge about the pathogenesis of schizophrenia may profit from an in-depth assessment of ABEs and their relationship with an abnormal sense of selfhood, especially in early schizophrenia. PMID:22239570

  1. 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. PMID:23558712

  2. Mathematical impairment associated with high-contrast abnormalities in change detection and magnocellular visual evoked response.

    PubMed

    Jastrzebski, Nicola R; Crewther, Sheila G; Crewther, David P

    2015-10-01

    The cause of developmental dyscalculia, a specific deficit in acquisition of arithmetic skills, particularly of enumeration, has never been investigated with respect to the patency of the visual magnocellular system. Here, the question of dysfunction of the afferent magnocellular cortical input and its dorsal stream projections was tested directly using nonlinear analysis of the visual evoked potential (VEP) and through the psychophysical ability to rapidly detect visual change. A group of young adults with self-reported deficiencies of arithmetical ability, showed marked impairment in magnitude estimation and enumeration performance-though not in lexical decision reaction times when compared with an arithmetically capable group controlled for age and handedness. Multifocal nonlinear VEPs were recorded at low (24 %) and high (96 %) contrast. First- and second-order VEP kernels were comparable between groups at low contrast, but not at high contrast. The mathematically impaired group showed an abnormal lack of contrast saturation in the shortest latency first-order peak (N60) and a delayed P100 positivity in the first slice of the second-order kernel. Both features have previously been argued to be physiological markers of magnocellular function. Mathematically impaired participants also performed worse on a gap paradigm change detection for digit task showing increased reaction times for high-contrast stimuli but not for low-contrast stimuli compared with controls. The VEP results give direct evidence of abnormality in the occipital processing of magnocellular information in those with mathematical impairment. The anomalous high visual contrast physiological and psychophysical performance suggests an abnormality in the inhibitory processes that normally result in saturation of contrast gain in the magnocellular system. PMID:26195163

  3. A ventral visual stream reading center independent of visual experience.

    PubMed

    Reich, Lior; Szwed, Marcin; Cohen, Laurent; Amedi, Amir

    2011-03-01

    The visual word form area (VWFA) is a ventral stream visual area that develops expertise for visual reading. It is activated across writing systems and scripts and encodes letter strings irrespective of case, font, or location in the visual field with striking anatomical reproducibility across individuals. In the blind, comparable reading expertise can be achieved using Braille. This study investigated which area plays the role of the VWFA in the blind. One would expect this area to be at either parietal or bilateral occipital cortex, reflecting the tactile nature of the task and crossmodal plasticity, respectively. However, according to the metamodal theory, which suggests that brain areas are responsive to a specific representation or computation regardless of their input sensory modality, we predicted recruitment of the left-hemispheric VWFA, identically to the sighted. Using functional magnetic resonance imaging, we show that activation during Braille reading in blind individuals peaks in the VWFA, with striking anatomical consistency within and between blind and sighted. Furthermore, the VWFA is reading selective when contrasted to high-level language and low-level sensory controls. Thus, we propose that the VWFA is a metamodal reading area that develops specialization for reading regardless of visual experience. PMID:21333539

  4. 196 Million Pixels: An Immersive Visualization Experience

    NASA Astrophysics Data System (ADS)

    Reed, P. J.; Vandenberg, A.; Wang, G.

    2011-12-01

    Georgia State University (GSU) has recently implemented one of the world's largest high-resolution, tiled visualization walls specifically designed for researcher accessibility and display of data in an interactive, immersive, exploratory and collaborative experience. The Visualization Wall, comprised of 48 individual high-resolution monitors, is able to analyze, evaluate, and present data using the latest earth science research software packages. Multi-core processing and 24 graphical processing units (GPU's) allow the system to process and view data using research software applications at high resolution (+196 million pixels), while maintaining an interactive experience for the user. A Windows platform solves many application compatibility obstacles but also presents a new host of problems when scaling applications across multiple monitors. Continuous data set visualization, frame rate slowing, and graphic performance have been a challenge with the Visualization Wall. To overcome these obstacles, GSU has implemented several innovative solutions including Google Code projects, hardware accelerated browsers, and open-source software such as SAGE.

  5. Prenatal Diagnosis of Chromosome Abnormalities: A 13-Year Institution Experience

    PubMed Central

    Comas, Carmen; Echevarria, Mónica; Rodríguez, María Ángeles; Rodríguez, Ignacio; Serra, Bernat; Cirigliano, Vincenzo

    2012-01-01

    Objective: To analyze trends in screening and invasive prenatal diagnosis of chromosome abnormalities (CA) over a 13-year period and correlate them to changes in the national prenatal screening policy. Methods: We retrospectively reviewed Down syndrome (DS) screening tests and fetal karyotypes obtained by prenatal invasive testing (IT) in our fetal medicine unit between January 1999 and December 2011. Results: A total of 24,226 prenatal screening tests for DS and 11,045 invasive procedures have been analyzed. Over a 13-year period, utilization of non-invasive screening methods has significantly increased from 57% to 89%. The percentage of invasive procedures has declined from 49% to 12%, although the percentage of IT performed for maternal anxiety has increased from 22% to 55%. The percentage of detected CA increased from 2.5% to 5.9%. Overall, 31 invasive procedures are needed to diagnose 1 abnormal case, being 23 procedures in medical indications and 241 procedures in non-medical indications. Conclusions: Our experience on screening and invasive prenatal diagnostic practice shows a decrease of the number of IT, with a parallel decline in medical indications. There is an increasing efficiency of prenatal screening program to detect CA. Despite the increasing screening policies, our population shows a growing request for prenatal IT. The a priori low risk population shows a not negligible residual risk for relevant CA. This observation challenges the current prenatal screening strategy focused on DS; showing that the residual risk is higher than the current cut-off used to indicate an invasive technique. PMID:26859399

  6. Serendipity in Technetium-99m dimethyl iminodiacetic acid cholescintigraphy. [Visualization of nonbiliary incidental abnormalities

    SciTech Connect

    Weissmann, H.S.; Sugarman, L.A.; Frank, M.S.; Freeman, L.M.

    1980-05-01

    Technetium-99m dimethyl iminodiacetic acid cholescintigraphy has contributed significantly to the diagnosis of acute and chronic biliary tract disorders. Yet attention should also be focused on the other structres visualized during the blood pool, hepatocyte, renal excretory, and intestinal phases of the study. Nonbiliary pathology was detected in 42 of 294 patients (14.3%) studied for suspected acute cholecystitis. The serendipitous detection of previously unsuspected abnormalities assisted in directing further work-up away from suspected biliary disease and towards the real source of the patient's acute problem in 28 cases (9.5%).

  7. Behavioral Objectives for Classroom Experiences in Visual Literacy.

    ERIC Educational Resources Information Center

    Barley, Steven D.

    Behavioral objectives for visual literacy experiences are briefly delineated. The objectives concern skills related to: informative visual communication, persuasive and/or visual communication, general visual communication, visual concepts, and reading visual materials, as well as aesthetic and/or recreational skills. For example, the behavioral…

  8. 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.

  9. Experiences of patients with abnormal extubation of PICC tubes: a qualitative study

    PubMed Central

    Gao, Wei; Luan, Xiao-Rong; Sun, Yuan-Yuan; Zhang, Ming; Li, Kan; Li, Qiu-Huan; Zhang, Hong; Liu, De-Shan

    2015-01-01

    Objective: To explore the experiences of patients with abnormal extubation of PICC tubes. Methods: Using phenomenological research methods, 15 cases of patients with abnormal extubation of PICC tubes were enrolled in semi-structured interviews. Data were analyzed by Nancy’s phenomenological procedure. Results: After abnormal extubation, patients exhibited conflicting complicated mood which combined negative experience and positive experience. Negative experience was mainly for complaint, helpless, worry and fear. Positive experience was mainly for relief and peace of mind. Conclusions: Patients with abnormal extubation often possessed negative experience. So nursing staff should be suggested to communicate with patients before extubation in order to reduce the dispute between nurses and patients. At the same time, we should summarize and analyze the reasons and factors for abnormal extubation, and take targeted intervention measures in clinical to ensure the safety and effectiveness of PICC extubation. PMID:26770567

  10. 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…

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. Subjective Visual Vertical and Horizontal Abnormalities in a Patient with Lateral Medullary Syndrome-A Case Report

    PubMed Central

    Tyagi, Amit Kumar; Ashish, Gaurav; Lepcha, Anjali; Balraj, Achamma

    2015-01-01

    Introduction: Evaluation of persistent vertigo in post infarct patients is very important as the management depends on whether the cause is purely of central origin or due to associated vestibular affliction. Case Report: A patient with left sided dorsolateral medullary syndrome and persistent vestibular symptoms was evaluated. Vestibular test battery showed abnormal smooth pursuit, bilateral hyperactive caloric responses, and abnormal dynamic subjective visual vertical and dynamic subjective visual horizontal tests. Conclusion: Dorsolateral medullary infarctions (Wallenberg’s syndrome) typically cause a central vestibular tonus imbalance in the roll plane with ipsilateral deviations of perceived vertical orientation. The SVV and SVH tests may have a role in localizing the pathology in a patient with lateral medullary syndrome. PMID:25745615

  16. 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…

  17. 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…

  18. Detecting Visual Function Abnormality with a Contrast-Dependent Visual Test in Patients with Type 2 Diabetes.

    PubMed

    Tsai, Li-Ting; Liao, Kuo-Meng; Jang, Yuh; Hu, Fu-Chang; Wu, Wei-Chi

    2016-01-01

    In addition to diabetic retinopathy, diabetes also causes early retinal neurodegeneration and other eye problems, which cause various types of visual deficits. This study used a computer-based visual test (Macular Multi-Function Assessment (MMFA)) to assess contrast-dependent macular visual function in patients with type 2 diabetes to collect more visual information than possible with only the visual acuity test. Because the MMFA is a newly developed test, this study first compared the agreement and discriminative ability of the MMFA and the Early Treatment Diabetic Retinopathy Study (ETDRS) contrast acuity charts. Then symbol discrimination performances of diabetic patients and controls were evaluated at 4 contrast levels using the MMFA. Seventy-seven patients and 45 controls participated. The agreement between MMFA and ETDRS scores was examined by fitting three-level linear mixed-effect models to estimate the intraclass correlation coefficients (ICCs). The estimated areas under the receiver operating characteristic (ROC) curve were used to compare the discriminative ability of diseased versus non-diseased participants between the two tests. The MMFA scores of patients and controls were compared with multiple linear regression analysis after adjusting the effects of age, sex, hypertension and cataract. Results showed that the scores of the MMFA and ETDRS tests displayed high levels of agreement and acceptable and similar discriminative ability. The MMFA performance was correlated with the severity of diabetic retinopathy. Most of the MMFA scores differed significantly between the diabetic patients and controls. In the low contrast condition, the MMFA scores were significantly lower for 006Eon-DR patients than for controls. The potential utility of the MMFA as an easy screening tool for contrast-dependent visual function and for detecting early functional visual change in patients with type 2 diabetes is discussed. PMID:27611680

  19. Effects of attention on visual experience during monocular rivalry

    PubMed Central

    Reavis, Eric A.; Kohler, Peter J.; Caplovitz, Gideon P.; Wheatley, Thalia P.; Tse, Peter U.

    2013-01-01

    There is a long-running debate over the extent to which volitional attention can modulate the appearance of visual stimuli. Here we use monocular rivalry between afterimages to explore the effects of attention on the contents of visual experience. In three experiments, we demonstrate that attended afterimages are seen for longer periods, on average, than unattended afterimages. This occurs both when a feature of the afterimage is attended directly and when a frame surrounding the afterimage is attended. The results of these experiments show that volitional attention can dramatically influence the contents of visual experience. PMID:23499978

  20. Sensory deprivation: visual experience alters the mental number line.

    PubMed

    Pasqualotto, Achille; Taya, Shuichiro; Proulx, Michael J

    2014-03-15

    Early studies on numeric cognition reported that numbers are spatially organised according to a left-to-right small-to-large 'number line'. We investigated whether this spatial-number organisation is dictated by visual experience. We tested congenitally and late blind, and blindfolded sighted participants in a random number generation task where in one block their heads were alternately turned left or right before uttering the number. We found that the 'random' number generation was biased according to the side where the head was turned to. Consistent with the standard number line, participants with visual experience generated smaller numbers for left turns, and larger numbers for right turns. In contrast, participants without any visual experience showed the opposite pattern of results. These results suggest a role for visual experience in the development of spatial and numerical representations, which is supported by cultural differences in number representation, and provide converging evidence for visually driven organisation of the parietal cortex. PMID:24355751

  1. 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. PMID:25555776

  2. Experience-Dependent Changes in Excitatory and Inhibitory Receptor Subunit Expression in Visual Cortex

    PubMed Central

    Beston, Brett R.; Jones, David G.; Murphy, Kathryn M.

    2010-01-01

    Experience-dependent development of visual cortex depends on the balance between excitatory and inhibitory activity. This activity is regulated by key excitatory (NMDA, AMPA) and inhibitory (GABAA) receptors. The composition of these receptors changes developmentally, affecting the excitatory–inhibitory (E/I) balance and synaptic plasticity. Until now, it has been unclear how abnormal visual experience affects this balance. To examine this question, we measured developmental changes in excitatory and inhibitory receptor subunits in visual cortex following normal visual experience and monocular deprivation. We used Western blot analysis to quantify expression of excitatory (NR1, NR2A, NR2B, GluR2) and inhibitory (GABAAα1, GABAAα3) receptor subunits. Monocular deprivation promoted a complex pattern of changes in receptor subunit expression that varied with age and was most severe in the region of visual cortex representing the central visual field. To characterize the multidimensional pattern of experience-dependent change in these synaptic mechanisms, we applied a neuroinformatics approach using principal component analysis. We found that monocular deprivation (i) causes a large portion of the normal developmental trajectory to be bypassed, (ii) shifts the E/I balance in favor of more inhibition, and (iii) accelerates the maturation of receptor subunits. Taken together, these results show that monocularly deprived animals have an abnormal balance of the synaptic machinery needed for functional maturation of cortical circuits and for developmental plasticity. This raises the possibility that interventions intended to treat amblyopia may need to address multiple synaptic mechanisms to produce optimal recovery. PMID:21423524

  3. 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.

  4. [Lived experience of women with fetal chromosomal abnormality receiving termination at second trimester].

    PubMed

    Hsu, Chin-Mei; Su, Tsann-Juu; Chen, Yueh-Chih; Hwang, Jiann-Lonng

    2007-12-01

    Fetal chromosomal examination helps screen fetal chromosomal abnormalities prenatally. Diagnosis of such anomalies allows pregnancy termination, but causes tremendous trauma during pregnancy. The purpose of this study was to explore the lived experience of women suffering from fetal chromosomal abnormalities who are urgently required to terminate their pregnancy. The qualitative field study was conducted at a medical center in Taipei. The researcher, a primary nurse, conducted interviews with five women face to face or over the phone to collect the data. The period of care lasted for two weeks, beginning with confirmed diagnosis of fetal chromosomal abnormalities, followed by the subjects' decision on pregnancy termination, and ending up with their discharge from the hospital. The study is presented in narrative form and the data analyzed using interpretive research strategies of phenomenology. Three categories of lived experience emerged from the data: (1) recurring nightmares, (2) the torment from making the decision of pregnancy termination, and (3) frustration or sadness afterwards. The results illustrated that the lived experience of the women suffering from fetal chromosomal abnormalities and receiving termination was a continuous process. We suggest that medical staff concern themselves with the issue and provide humanistic caring for patients during the various different phases. PMID:18098106

  5. 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. PMID:27578350

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

    PubMed

    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

  7. 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.

  8. 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'…

  9. Sharing visualization experiences among remote virtual environments

    SciTech Connect

    Disz, T.L.; Papka, M.E.; Pellegrino, M.; Stevens, R.

    1995-12-31

    Virtual reality has become an increasingly familiar part of the science of visualization and communication of information. This, combined with the increase in connectivity of remote sites via high-speed networks, allows for the development of a collaborative distributed virtual environment. Such an environment enables the development of supercomputer simulations with virtual reality visualizations that can be displayed at multiple sites, with each site interacting, viewing, and communicating about the results being discovered. The early results of an experimental collaborative virtual reality environment are discussed in this paper. The issues that need to be addressed in the implementation, as well as preliminary results are covered. Also provided are a discussion of plans and a generalized application programmers interface for CAVE to CAVE will be provided.

  10. Type 2 blindsight and the nature of visual experience.

    PubMed

    Brogaard, Berit

    2015-03-01

    Blindsight is a kind of residual vision found in people with lesions to V1. Subjects with blindsight typically report no visual awareness, but they are nonetheless able to make above-chance guesses about the shape, location, color and movement of visual stimuli presented to them in their blind field. A different kind of blindsight, sometimes called type 2 blindsight, is a kind of residual vision found in patients with V1 lesions in the presence of some residual awareness. Type 2 blindsight differs from ordinary visual experience in lacking the particularity, transparency and fine-grainedness often taken to be essential to visual experience, at least in veridical cases. I argue that the case of type 2 blindsight provides a counterexample to the view that these characteristics are essential to veridical visual experience and that this gives us reason to resist the view that visual experience is essentially a perceptual relation to external objects. In the second part of the paper I argue that the case of type 2 blindsight yields important insights into the effects of attentional modulation on perceptual content and that cases of attentional modulation of appearance are not at odds with the view that the phenomenology of visual experience flows from its content. PMID:25456073

  11. Flow visualization experiments in a porous nozzle

    NASA Technical Reports Server (NTRS)

    Cielak, Z.; Kinney, R. B.; Perkins, H. C.

    1973-01-01

    An experimental approach is described for the study of nozzle flows with large wall-transpiration rates. Emphasizing a qualitative understanding of the flow, the technique uses the hydraulic analogy, whereby a compressible gas flow is simulated by a water flow having a free surface. For simplicity, the simulated gas flow is taken to be two-dimensional. A nozzle with porous walls in the throat region has been developed for use on a water table. A technique for visualizing the transpired fluid has also been devised. These are discussed, and preliminary results are presented which illustrate the success of the experimental approach.

  12. Experience Rate of Elbow Pain and Morphological Abnormality of Humeral Medial Epicondyle among Youth Baseball Players

    PubMed Central

    Kotoura, Yoshihiro; Morihara, Toru; Kida, Yoshikazu; Sukenari, Tsuyoshi; Furukawa, Ryuhei; Kabuto, Yukichi; MInami, Masataka; Onishi, Okihiro; Tsujihara, Takashi; Hojo, Tatsuya; Fujiwara, Hiroyoshi; Kubo, Toshikazu

    2016-01-01

    Objectives: The aim of this study was to investigate the experience rate of elbow pain and to clarify the relationship between morphological abnormality of the humeral medial epicondyle and positions among baseball players in elementary school (ES), junior high school (JHS) and high school (HS). Methods: In this study, 4353 baseball players who participated in our medical screening (2008-2015) were enrolled. There were 1545 players from ES, 1934 players from JHS, and 874 players from HS. We asked them to answer the questionnaire to investigate the experience of elbow pain, and the position they played. Ultrasonography of the humeral medial epicondyle was examined and irregularity, fragmentation, and malunion of the humeral medial epicondyle. The results were analyzed statistically. P < 0.05 was considered significant for all statistical analyses. Results: The experience rates of elbow pain among players in ES, JHS, and HS were 26.0%, 27.0%, and 68.3%. The rates of abnormality of humeral medial epicondyle among players in ES, JHS, and HS were 18.2%, 36.3%, and 39.9% (Table 1). The experience rate of elbow pain among pitchers and catchers was significantly higher than the fielders in ES (Table 2), however, there were no significant differences between positions in JHS and HS (Table 3,4). According to the rate of morphological abnormalities of humeral medial epicondyle, pitchers and catchers were significantly higher than fielders in ES, while only pitchers were significantly higher than the fielders in JHS and HS (Table 2,3,4). Conclusion: The experience rate of elbow pain among baseball players rose as the age increased, and the rate in HS was almost 70%. The rates of morphological abnormality of humeral medial epicondyle among pitchers and catchers were high and the tendency was observed from a young age. The primary prevention of elbow injuries in youth baseball players of all ages should be considered.

  13. Abnormal Attention in Autism Shown by Steady-State Visual Evoked Potentials.

    ERIC Educational Resources Information Center

    Belmonte, Matthew

    2000-01-01

    Eight males with autism were required to shift attention between rapidly flashed targets alternating between left and right visual hemifields. When targets were separated by less than 700 ms, steady-state brain electrical response in both hemispheres was augmented and background EEG decreased for rightward shifts as compared with leftward shifts.…

  14. Cortical stimulation consolidates and reactivates visual experience: neural plasticity from magnetic entrainment of visual activity.

    PubMed

    Liao, Hsin-I; Wu, Daw-An; Halelamien, Neil; Shimojo, Shinsuke

    2013-01-01

    Delivering transcranial magnetic stimulation (TMS) shortly after the end of a visual stimulus can cause a TMS-induced 'replay' or 'visual echo' of the visual percept. In the current study, we find an entrainment effect that after repeated elicitations of TMS-induced replay with the same visual stimulus, the replay can be induced by TMS alone, without the need for the physical visual stimulus. In Experiment 1, we used a subjective rating task to examine the phenomenal aspects of TMS-entrained replays. In Experiment 2, we used an objective masking paradigm to quantitatively validate the phenomenon and to examine the involvement of low-level mechanisms. Results showed that the TMS-entrained replay was not only phenomenally experienced (Exp.1), but also able to hamper letter identification (Exp.2). The findings have implications in several directions: (1) the visual cortical representation and iconic memory, (2) experience-based plasticity in the visual cortex, and (3) their relationship to visual awareness. PMID:23863977

  15. Sensory experience modifies feature map relationships in visual cortex.

    PubMed

    Cloherty, Shaun L; Hughes, Nicholas J; Hietanen, Markus A; Bhagavatula, Partha S; Goodhill, Geoffrey J; Ibbotson, Michael R

    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. PMID:27310531

  16. 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

  17. 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.

  18. 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…

  19. Collaborative Graphic Rendering for Improving Visual Experience

    NASA Astrophysics Data System (ADS)

    Wu, Xiaoxin; Pei, Guodong

    Handheld devices such as UMPC, though convenient, bear weakness of size constraint for display. To mitigate such a problem and enhance user experience for owners of small devices, in this paper we design a collaborative rendering platform. When running game graphic applications at a handheld, the generated OpenGL graphic commands are intercepted and then delivered to a device with a larger display. The graphics are rendered and displayed at that device. The performance of the collaborative rendering platform is determined by graphic computing resources and network bandwidth. Analysis and simulation prove that other than providing a better display, the collaborative system can improve game experience also by increasing frame rates. In particular, at a low computing cost, a further collaboration between GPUs of collaborators can improve frame rate by eliminating the negative impact from network delay on applications that require GPU feedback.

  20. A Simple Experiment for Visualizing Diffusion

    ERIC Educational Resources Information Center

    Helseth, L. E.

    2011-01-01

    We propose a simple and fascinating experiment for studying diffusion in gels using a pH-sensitive dye. By doping agar with methyl red, we obtain a gel which rapidly reacts to changes in pH by changing its absorption spectrum. The pH gradients can be followed using a digital camera, and we demonstrate here that the pH-sensitive colour changes can…

  1. Abnormal visual-evoked potentials in leukemic children after cranial radiation

    SciTech Connect

    Russo, A.; Tomarchio, S.; Pero, G.; Consoli, G.; Marina, R.; Rizzari, C.; Schiliro, G.

    1985-01-01

    Visual-evoked potentials (VEPs) were studied in 55 asymptomatic children with leukemia or solid tumors in remission in order to detect subclinical demyelination of the optic pathway after CNS prophylaxis. In group I (11 patients with ALL studied prospectively), VEP latency was increased in ten after cranial radiation (CR) as compared with previous values. Group II (18 patients with ALL in maintenance) and group III (16 patients with ALL off therapy) were studied retrospectively and VEP latency was found above normal limits in 33 and 31%, respectively. In group IV (four patients with solid tumors and six with leukemia, all of whom received no CR), VEP latency was normal despite periodical intrathecal methotrexate administrations to five of them. The authors conclude that CR determines a slowing of conduction on VEP test, probably due to demyelination of the optic pathway, in a high proportion of patients. The future clinical significance of these findings must be established throughout a prolonged follow-up period.

  2. 3D PATTERN OF BRAIN ABNORMALITIES IN WILLIAMS SYNDROME VISUALIZED USING TENSOR-BASED MORPHOMETRY

    PubMed Central

    Chiang, Ming-Chang; Reiss, Allan L.; Lee, Agatha D.; Bellugi, Ursula; Galaburda, Albert M.; Korenberg, Julie R.; Mills, Debra L.; Toga, Arthur W.; Thompson, Paul M.

    2009-01-01

    Williams syndrome (WS) is a neurodevelopmental disorder associated with deletion of ~20 contiguous genes in chromosome band 7q11.23. Individuals with WS exhibit mild to moderate mental retardation, but are relatively more proficient in specific language and musical abilities. We used tensor-based morphometry (TBM) to visualize the complex pattern of gray/white matter reductions in WS, based on fluid registration of structural brain images. Methods 3D T1-weighted brain MRIs of 41 WS subjects (age: 29.2±9.2SD years; 23F/18M) and 39 age-matched healthy controls (age: 27.5±7.4 years; 23F/16M) were fluidly registered to a minimum deformation target. Fine-scale volumetric differences were mapped between diagnostic groups. Local regions were identified where regional structure volumes were associated with diagnosis, and with intelligence quotient (IQ) scores. Brain asymmetry was also mapped and compared between diagnostic groups. Results WS subjects exhibited widely distributed brain volume reductions (~10–15% reduction; P < 0.0002, permutation test). After adjusting for total brain volume, the frontal lobes, anterior cingulate, superior temporal gyrus, amygdala, fusiform gyrus and cerebellum were found to be relatively preserved in WS, but parietal and occipital lobes, thalamus and basal ganglia, and midbrain were disproportionally decreased in volume (P < 0.0002). These regional volumes also correlated positively with performance IQ in adult WS subjects (age ≥ 30 years, P = 0.038). Conclusion TBM facilitates 3D visualization of brain volume reductions in WS. Reduced parietal/occipital volumes may be associated with visuospatial deficits in WS. By contrast, frontal lobes, amygdala, and cingulate gyrus are relatively preserved or even enlarged, consistent with unusual affect regulation and language production in WS. PMID:17512756

  3. Does bilingual experience affect early visual perceptual development?

    PubMed Central

    Schonberg, Christina; Sandhofer, Catherine M.; Tsang, Tawny; Johnson, Scott P.

    2014-01-01

    Visual attention and perception develop rapidly during the first few months after birth, and these behaviors are critical components in the development of language and cognitive abilities. Here we ask how early bilingual experiences might lead to differences in visual attention and perception. Experiments 1–3 investigated the looking behavior of monolingual and bilingual infants when presented with social (Experiment 1), mixed (Experiment 2), or non-social (Experiment 3) stimuli. In each of these experiments, infants' dwell times (DT) and number of fixations to areas of interest (AOIs) were analyzed, giving a sense of where the infants looked. To examine how the infants looked at the stimuli in a more global sense, Experiment 4 combined and analyzed the saccade data collected in Experiments 1–3. There were no significant differences between monolingual and bilingual infants' DTs, AOI fixations, or saccade characteristics (specifically, frequency, and amplitude) in any of the experiments. These results suggest that monolingual and bilingual infants process their visual environments similarly, supporting the idea that the substantial cognitive differences between monolinguals and bilinguals in early childhood are more related to active vocabulary production than perception of the environment. PMID:25566116

  4. Face to face: visual scanpath evidence for abnormal processing of facial expressions in social phobia.

    PubMed

    Horley, Kaye; Williams, Leanne M; Gonsalvez, Craig; Gordon, Evian

    2004-06-30

    Cognitive models of social phobia propose that cognitive biases and fears regarding negative evaluation by others result in preferential attention to interpersonal sources of threat. These fears may account for the hypervigilance and avoidance of eye contact commonly reported by clinicians. This study provides the first objective examination of threat-related processing in social phobia. It was predicted that hyperscanning (hypervigilance) and eye avoidance would be most apparent in social phobia for overt expressions of threat. An infrared corneal reflection technique was used to record visual scanpaths in response to angry, sad, and happy vs. neutral facial expressions. Twenty-two subjects with social phobia were compared with age- and sex-matched normal controls. As predicted, social phobia subjects displayed hyperscanning, (increased scanpath length) and avoidance (reduced foveal fixations) of the eyes, particularly evident for angry faces. The results could not be explained by either medication or co-morbid depression. These findings are consistent with theories emphasising the role of information processing biases in social phobia, and show promise in the application to treatment evaluation in this disorder. PMID:15261704

  5. Object-based attention benefits reveal selective abnormalities of visual integration in autism.

    PubMed

    Falter, Christine M; Grant, Kate C Plaisted; Davis, Greg

    2010-06-01

    A pervasive integration deficit could provide a powerful and elegant account of cognitive processing in autism spectrum disorders (ASD). However, in the case of visual Gestalt grouping, typically assessed by tasks that require participants explicitly to introspect on their own grouping perception, clear evidence for such a deficit remains elusive. To resolve this issue, we adopt an index of Gestalt grouping from the object-based attention literature that does not require participants to assess their own grouping perception. Children with ASD and mental- and chronological-age matched typically developing children (TD) performed speeded orientation discriminations of two diagonal lines. The lines were superimposed on circles that were either grouped together or segmented on the basis of color, proximity or these two dimensions in competition. The magnitude of performance benefits evident for grouped circles, relative to ungrouped circles, provided an index of grouping under various conditions. Children with ASD showed comparable grouping by proximity to the TD group, but reduced grouping by similarity. ASD seems characterized by a selective bias away from grouping by similarity combined with typical levels of grouping by proximity, rather than by a pervasive integration deficit. PMID:20578070

  6. Early Visual Mechanisms Do Not Contribute to Synesthetic Color Experience

    PubMed Central

    Hong, Sang Wook; Blake, Randolph

    2008-01-01

    Color-graphemic synesthetes perceive colors when viewing alphanumeric characters. Theories of color-graphemic synesthesia posit that synesthetic color experience arises from activation of neural mechanisms also involved in ordinary color vision. To learn how early in visual processing those mechanisms exist, we performed several experiments. In one experiment, real colors were altered in appearance by the lightness of their backgrounds, but the appearance of synesthetic colors was immune to surrounding light levels. In the second experiment using a hue cancellation technique, adaptation to synesthetic color had no subsequent effect on the amount of canceling light to achieve equilibrium yellow, whereas adaptation to real colors did. In the third experiment, vivid synesthetic color had no influence on equilibrium yellow settings of the actual color of the characters evoking synesthesia. Because brightness contrast and chromatic adaptation are putatively mediated by neural mechanisms early in visual processing including retina and primary visual cortex, our results imply that neural events responsible for synesthetic color emerge subsequent to these early visual stages. PMID:18316107

  7. Abnormal brain activation and connectivity to standardized disorder-related visual scenes in social anxiety disorder.

    PubMed

    Heitmann, Carina Yvonne; Feldker, Katharina; Neumeister, Paula; Zepp, Britta Maria; Peterburs, Jutta; Zwitserlood, Pienie; Straube, Thomas

    2016-04-01

    Our understanding of altered emotional processing in social anxiety disorder (SAD) is hampered by a heterogeneity of findings, which is probably due to the vastly different methods and materials used so far. This is why the present functional magnetic resonance imaging (fMRI) study investigated immediate disorder-related threat processing in 30 SAD patients and 30 healthy controls (HC) with a novel, standardized set of highly ecologically valid, disorder-related complex visual scenes. SAD patients rated disorder-related as compared with neutral scenes as more unpleasant, arousing and anxiety-inducing than HC. On the neural level, disorder-related as compared with neutral scenes evoked differential responses in SAD patients in a widespread emotion processing network including (para-)limbic structures (e.g. amygdala, insula, thalamus, globus pallidus) and cortical regions (e.g. dorsomedial prefrontal cortex (dmPFC), posterior cingulate cortex (PCC), and precuneus). Functional connectivity analysis yielded an altered interplay between PCC/precuneus and paralimbic (insula) as well as cortical regions (dmPFC, precuneus) in SAD patients, which emphasizes a central role for PCC/precuneus in disorder-related scene processing. Hyperconnectivity of globus pallidus with amygdala, anterior cingulate cortex (ACC) and medial prefrontal cortex (mPFC) additionally underlines the relevance of this region in socially anxious threat processing. Our findings stress the importance of specific disorder-related stimuli for the investigation of altered emotion processing in SAD. Disorder-related threat processing in SAD reveals anomalies at multiple stages of emotion processing which may be linked to increased anxiety and to dysfunctionally elevated levels of self-referential processing reported in previous studies. PMID:26806013

  8. 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

  9. Visual Experience Modulates Spatio-Temporal Dynamics of Circuit Activation

    PubMed Central

    Wang, Lang; Fontanini, Alfredo; Maffei, Arianna

    2011-01-01

    Persistent reduction in sensory drive in early development results in multiple plastic changes of different cortical synapses. How these experience-dependent modifications affect the spatio-temporal dynamics of signal propagation in neocortical circuits is poorly understood. Here we demonstrate that brief visual deprivation significantly affects the propagation of electrical signals in the primary visual cortex. The spatio-temporal spread of circuit activation upon direct stimulation of its input layer (Layer 4) is reduced, as is the activation of L2/3 – the main recipient of the output from L4. Our data suggest that the decrease in spatio-temporal activation of L2/3 depends on reduced L4 output, and is not intrinsically generated within L2/3. The data shown here suggest that changes in the synaptic components of the visual cortical circuit result not only in alteration of local integration of excitatory and inhibitory inputs, but also in a significant decrease in overall circuit activation. Furthermore, our data indicate a differential effect of visual deprivation on L4 and L2/3, suggesting that while feedforward activation of L2/3 is reduced, its activation by long range, within layer inputs is unaltered. Thus, brief visual deprivation induces experience-dependent circuit re-organization by modulating not only circuit excitability, but also the spatio-temporal patterns of cortical activation within and between layers. PMID:21743804

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

    SciTech Connect

    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.

  11. Increased apoptosis and abnormal visual behavior by histone modifications with exposure to para-xylene in developing Xenopus.

    PubMed

    Gao, Juanmei; Ruan, Hangze; Qi, Xianjie; Guo, Xia; Zheng, Jingna; Liu, Cong; Fang, Yanxiao; Huang, Minjiao; Xu, Miao; Shen, Wanhua

    2016-09-01

    Xylene and its derivatives are raw materials widely used in industry and known to be toxic to animals. However, the mechanism underlying the neurotoxicity of para-xylene (PX) to the central nervous system (CNS) in vivo is less clear. Here, we exposed Xenopus laevis tadpoles to sub-lethal concentrations of PX during the critical period of brain development to determine the effects of PX on Xenopus development and visual behavior. We found that the abnormality rate was significantly increased with exposure to increasing concentrations of PX. In particular, the number of apoptotic cells in the optic tectum was dramatically increased with exposure to PX at 2mM. Long-term PX exposure also resulted in significant deficits in visually guided avoidance behavior. Strikingly, co-incubation with PX and d-glucuronolactone (GA) decreased the number of apoptotic cells and rescued the avoidance behavior. Furthermore, we found that the acetylation of H4K12 (H4K12ac) and the dimethylation of H3K9 (H3K9me2) in the optic tectum were significantly increased in PX-treated animals, and these effects were suppressed by GA treatment. In particular, the increase in apoptotic cells in PX-treated brains was also inhibited by GA treatment. These effects indicate that epigenetic regulation plays a key role in PX-induced apoptosis and animal behavior. In an effort to characterize the neurotoxic effects of PX on brain development and behavior, these results suggest that the neurotoxicity of PX requires further evaluation regarding the safety of commercial and industrial uses. PMID:27343828

  12. Gap Effect Abnormalities during a Visually Guided Pro-Saccade Task in Children with Attention Deficit Hyperactivity Disorder

    PubMed Central

    Taniike, Masako; Mohri, Ikuko; Kobashi, Syoji; Tachibana, Masaya; Kobayashi, Yasushi; Kitamura, Yuri

    2015-01-01

    Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that starts in early childhood and has a comprehensive impact on psychosocial activity and education as well as general health across the lifespan. Despite its prevalence, the current diagnostic criteria for ADHD are debated. Saccadic eye movements are easy to quantify and may be a quantitative biomarker for a wide variety of neurological and psychiatric disorders, including ADHD. The goal of this study was to examine whether children with ADHD exhibit abnormalities during a visually guided pro-saccadic eye-movement and to clarify the neurophysiological mechanisms associated with their behavioral impairments. Thirty-seven children with ADHD (aged 5–11 years) and 88 typically developing (TD) children (aged 5–11 years) were asked to perform a simple saccadic eye-movement task in which step and gap conditions were randomly interleaved. We evaluated the gap effect, which is the difference in the reaction time between the two conditions. Children with ADHD had a significantly longer reaction time than TD children (p < 0.01) and the gap effect was markedly attenuated (p < 0.01). These results suggest that the measurement of saccadic eye movements may provide a novel method for evaluating the behavioral symptoms and clinical features of ADHD, and that the gap effect is a potential biomarker for the diagnosis of ADHD in early childhood. PMID:26018057

  13. 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. PMID:25943123

  14. Visual experience induces long-term potentiation (LTP) in the primary visual cortex

    PubMed Central

    Cooke, Sam F.; Bear, Mark F.

    2010-01-01

    Stimulus-specific response potentiation (SRP) is a robust form of experience-dependent plasticity that occurs in primary visual cortex. In awake mice, visual evoked potentials (VEPs) recorded in layer 4 of binocular visual cortex undergo increases in amplitude with repeated presentation of a sinusoidal grating stimulus over days. This effect is highly specific to the experienced stimulus. Here, we test whether the mechanisms of thalamocortical LTP, induced with a theta-burst electrical stimulation (TBS) of the dorsal lateral geniculate nucleus (dLGN), are sufficient to account for SRP. First, we demonstrate that LTP similarly enhances the amplitude of VEPs, but in a way that generalizes across multiple stimuli, spatial frequencies, and contrasts. Second, we show that LTP occludes the subsequent expression of SRP. Third, we reveal that prior SRP occludes TBS-induced LTP of the VEP evoked by the experienced stimulus, but not by unfamiliar stimuli. Finally, we show that SRP is rapidly and selectively reversed by local cortical infusion of a peptide that inhibits PKMζ, a constitutively active kinase known to maintain NMDA receptor-dependent LTP and memory. Thus, SRP is expressed by the same core mechanisms as LTP. SRP therefore provides a simple assay to assess the integrity of LTP in the intact nervous system. Moreover, the results suggest that LTP of visual cortex, like SRP, can potentially be exploited to improve vision. PMID:21123576

  15. Cryogenic Fracturing: Laboratory Visualization Experiments and Numerical Simulations Using Peridynamics

    NASA Astrophysics Data System (ADS)

    Martin-Short, R.; Edmiston, J. K.

    2015-12-01

    Typical hydraulic fracturing operations involve the use of a large quantity of water, which can be problematic for several reasons including possible formation (permeability) damage, disposal of waste water, and the use of precious local water resource. An alternate reservoir permeability enhancing technology not requiring water is cryogenic fracturing. This method induces controlled fracturing of rock formations by thermal shock and has potentially important applications in the geothermal and hydrocarbon industries. In this process, cryogenic fluid—such as liquid nitrogen—is injected into the subsurface, causing fracturing due to thermal gradients. These fractures may improve the formation permeability relative to that achievable by hydraulic fracturing alone. We conducted combined laboratory visualization and numerical simulations studies of thermal-shock-induced fracture initiation and propagation resulting from liquid nitrogen injection in rock and analog materials. The experiment used transparent soda-lime glass cubes to facilitate real-time visualization of fracture growth and the fracture network geometry. In this contribution, we report the effect of overall temperature difference between cryogenic fluid and solid material on the produced fracture network, by pre-heating the glass cubes to several temperatures and injecting liquid nitrogen. Temperatures are monitored at several points by thermocouple and the fracture evolution is captured visually by camera. The experiment was modeled using a customized, thermoelastic, fracture-capable numerical simulation code based on peridynamics. The performance of the numerical code was validated by the results of the laboratory experiments, and then the code was used to study the different factors affecting a cryogenic fracturing operation, including the evolution of residual stresses and constitutive relationships for material failure. In complex rock such as shale, understanding the process of cryogenic

  16. Photochromic flow visualization in silicone oil for demonstrations and experiments

    NASA Astrophysics Data System (ADS)

    Fonda, Enrico; Johnston, Stephen R.; Ranjan, Devesh; Sreenivasan, Katepalli R.

    2015-11-01

    Photochromic dyes change color when illuminated, usually with UV light. As tracers for flow visualization they are non-intrusive, can selectively color the fluid, and are suitable for complex and confided flows. Availability of cheap 405nm high-power lasers combined with advances in image acquisition and image-processing technology, make these tracers particularly effective in creating convenient and engaging educational demonstrations as well as in qualitatively exploring flow structures. We present two low-cost demonstrations: laminar-flow reversibility using a Taylor-Couette device and a thermal convection flow. We also report our experience in studying large scales in high Prandtl numbers Rayleigh-Bénard convection.

  17. Exposure to traumatic experiences is associated with abnormal neural mechanism during charitable donation.

    PubMed

    Wei, Dongtao; Wang, Kangcheng; Shen, Yimo; Du, Xue; Li, Wenfu; Dupuis-Roy, Nicolas; Qiu, Jiang; Zhang, Qinglin

    2013-10-30

    Previous studies suggested that posttraumatic stress disorder (PTSD) might be associated with dysfunctional reward processing. At present, little is known about the neural mechanisms of reward-related processing during a charitable donation task in trauma survivors who do not go on to develop PTSD. We used functional magnetic resonance imaging (fMRI) to investigate the neural basis of charitable donation in non-PTSD survivors of the Sichuan earthquake. Results showed that activations in the striatum of trauma survivors were reduced in both the low donation (donated a small amount to the Red Cross) and the high donation conditions (donated a large amount to the Red Cross) compared with the healthy controls. Furthermore, the trauma survivors also exhibited less activity in the insula than the healthy controls in the high donation condition. These findings suggest that abnormal reward-related activations might be associated with dysfunctions in the reward pathway of trauma survivors. Also, we discuss the possibility that traumatic experiences attenuate the reactivity of reward-related brain areas to positive emotions (as induced by advantageous donations). PMID:23920149

  18. Experience-dependent gene expression in adult visual cortex.

    PubMed

    Chen, Jiabin; Yamahachi, Homare; Gilbert, Charles D

    2010-03-01

    Experience-dependent plasticity of the adult visual cortex underlies perceptual learning and recovery of function following central nervous system lesions. To reveal the signal transduction cascades involved in adult cortical plasticity, we utilized a model of remapping of cortical topography following binocular retinal lesions. In this model, the lesion projection zone (LPZ) of primary visual cortex (V1) recovers visually driven activity by the sprouting of horizontal axonal connections originating from the cells in the surrounding region. To explore the molecular mechanism underlying this process, we used gene microarrays from an expression library prepared from Macaque V1. By microarray analysis of gene expression levels in the LPZ and the surrounding region, and subsequent confirmation with Quantitative Real-Time polymerase chain reaction and in situ hybridization, the participation of a number of genes was observed, including the Rho GTPase family. Its role in regulation of cytoskeleton assembly provides a possible link between the alteration of neural activity and cortical functional reorganization. PMID:19571270

  19. 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. PMID:27427382

  20. 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. PMID:26619232

  1. Maintaining the cornea and the general physiological environment in visual neurophysiology experiments.

    PubMed

    Metha, A B; Crane, A M; Rylander, H G; Thomsen, S L; Albrecht, D G

    2001-08-30

    Neurophysiologists have been investigating the responses of neurons in the visual system for the past half-century using monkeys and cats that are anesthetized and paralyzed, with the non-blinking eyelids open for prolonged periods of time. Impermeable plastic contact lenses have been used to prevent dehydration of the corneal epithelium, which would otherwise occur in minutes. Unfortunately, such lenses rapidly introduce a variety of abnormal states that lead to clouding of the cornea, degradation of the retinal image, and premature termination of the experiment. To extend the viability of such preparations, a new protocol for maintenance of corneal health has been developed. The protocol uses rigid gas permeable contact lenses designed to maximize gas transmission, rigorous sterile methods, and a variety of methods for sustaining and monitoring the overall physiology of the animal. The effectiveness of the protocol was evaluated clinically by ophthalmoscopy before, during, and after the experiments, which lasted 8-10 days. Histopathology and quantitative histology were performed on the corneas following the experiment. Our observations showed that this protocol permits continuous contact lens wear without adversely affecting the corneas. Thus, it is possible to collect data 24 h each day, for the entire duration of the experiment. PMID:11513950

  2. 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

  3. Proton Radiography Experiment to Visualize Gas Bubbles in Mercury

    SciTech Connect

    Riemer, Bernie; Felde, David K; Wendel, Mark W; Mariam, Fesseha G; Merrill, Frank E

    2007-01-01

    An experiment to visualize small gas bubbles injected into mercury flowing in a test loop using proton radiography was conducted at the Los Alamos Neutron Science Center (LANSCE) in December 2006. Radiograph images of bubbles were obtained through two mercury thicknesses: 22 mm and 6 mm. Two jet bubblers and two needle bubblers were operated individually over a range of mercury flow speeds (0 - 1 m/s) and gas injection rates (0.1 - 500 sccm). Helium was most commonly used but Argon and Xenon were injected for limited test conditions. The smallest discernable bubbles were about 0.24 mm in diameter. Resolution was limited by image contrast which was notably improved with 6 mm of mercury thickness. Analysis of the radiograph images from jet bubbler conditions provided data on bubble size distribution and total bubble void fraction. In a few cases radiographs captured a large fraction of the injected gas, but generally 20 to 90% of injected gas was not captured in the images. In all more than 400 radiographs were made during the experiment in addition to several movies. Sound recordings of needle bubbler operation were also made and used to quantify bubble formation rate and size; these results are compared to theoretical predictions. This paper describes the experiment goals, scope and equipment; key results are presented and discussed.

  4. Neurocognitive deficits and neuroimaging abnormalities are prevalent in children with lupus: clinical and research experiences at a US pediatric institution.

    PubMed

    Muscal, E; Bloom, D R; Hunter, J V; Myones, B L

    2010-03-01

    Neurocognitive impairments and neuroimaging abnormalities are frequently observed in adults with systemic lupus erythematosus. There is a paucity of similar data in childhood-onset disease. We hypothesized that neurocognitive and neuroimaging abnormalities would be prevalent in children undergoing neuropsychological evaluations. We reviewed patient neurocognitive evaluations performed at a large United States pediatric institution during the period 2001 to 2008. Records were retrieved from 24 children referred to neuropsychology due to clinical indications. Data from 15 children enrolled in a prospective structure-function association study were also analyzed. Subjects were predominantly African-American and Hispanic adolescent girls of average intelligence. aPL positivity and aspirin use was prevalent. Neurocognitive impairment was designated in 70.8% of retrospective, and 46.7% of prospective cohort patients. Deficits were seen at times of wellness, without previous neuropsychiatric lupus, and early in disease courses. Scores >1.5 standard deviations below published age-matched norms were common in tests of executive functioning, visual memory and visual-spatial planning. Features of depression were seen in 33.3% of the children in the retrospective cohort (clinical referrals). Cerebral and cerebellar volume loss was observed in a majority of blinded prospective cohort research magnetic resonance images (73.3% and 67.7% respectively). White matter hyperintensities were observed in retrospective and prospective cohort magnetic resonance images (36.6% and 46.7% respectively). Larger prospective studies that elucidate structure-function associations in children with systemic lupus erythematosus are planned. PMID:20026519

  5. 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

  6. 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…

  7. 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…

  8. 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

  9. Cervical Cancer Prevention Knowledge and Abnormal Pap Test Experiences Among Women Living with HIV/AIDS.

    PubMed

    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

    2015-06-01

    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. We recruited 145 urban and rural WLHA from Ryan White-funded clinics and AIDS service organizations located in the southeastern USA 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. 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). 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

  10. A clinical algorithm for the management of abnormal mammograms. A community hospital's experience.

    PubMed Central

    Gist, D; Llorente, J; Mayer, J

    1997-01-01

    Mammography is an important tool in the early detection of breast cancer, but its use has been criticized for stimulating the performance of unnecessary breast biopsies. We retrospectively reviewed the results of breast biopsies preceded by abnormal mammograms at a community hospital for three 5-month periods--baseline, postintervention, and follow-up--to determine the effectiveness of algorithm-based care for patients with an abnormal mammogram. Cases in which there was a definite or implied recommendation for biopsy by a radiologist revealed a baseline positive predictive value of 4% (2/45), a postintervention positive predictive value of 21% (9/42), and a follow-up phase positive predictive value of 18% (5/28). A Fisher's exact test of the preintervention and postintervention positive predictive values after an abnormal mammogram with a "recommendation for biopsy" was significant (n = 87, P = .023). A Kruskal-Wallis analysis of variance to determine if there had been an increase in the mean lesion size of breast cancers detected over the 3 study periods was not significant. The results of this study suggest that developing a clinical algorithm under the leadership of an opinion leader combined with continuing medical education efforts may be efficacious in reducing the incidence of unnecessary surgical procedures. PMID:9074335

  11. 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

  12. Abnormal Brain Activation in Neurofibromatosis Type 1: A Link between Visual Processing and the Default Mode Network

    PubMed Central

    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. PMID:22723888

  13. Dense gas boundary layer experiments: Visualization, pressure measurements, concentration evaluation

    SciTech Connect

    Reichenbach, H.; Neuwald, P.; Kuhl, A.L.

    1992-11-01

    This technical report describes methods that were applied to investigate turbulent boundary layers generated by inviscid, baroclinic effects. The Cranz-Schardin 24-sparks camera was used to visualize the interactions of a planar shock wave with a Freon R12-layer. The shock propagates more slowly in the Freon layer than in air because of its smaller sound speed. This causes the shock front to be curved and to be reflected between the wall and the layer interface. As a consequence of the reflection process, a series of compression and expansion waves radiate from the layer. Large fluctuations in the streamwise velocity and in pressure develop for about 1 ms. These waves strongly perturb the interface shear layer, which rapidly transitions to a turbulent boundary flow. Pressure measurements showed that the fluctuations in the Freon layer reach a peak pressure 4 times higher than in the turbulent boundary flow. To characterize the preshock Freon boundary layer, concentration measurements were performed with a differential interferometry technique. The refraction index of Freon R12 is so high that Mach-Zehnder interferometry was not successful in these experiments. The evaluation of the concentration profile is described here in detail. Method and results of corresponding LDV measurements under the same conditions are presented in a different report, EMI Report T 9/92. The authors plan to continue the dense gas layer investigations with the gas combination helium/Freon.

  14. Does visual experience influence the spatial distribution of auditory attention?

    PubMed

    Lerens, Elodie; Renier, Laurent

    2014-02-01

    Sighted individuals are less accurate and slower to localize sounds coming from the peripheral space than sounds coming from the frontal space. This specific bias in favour of the frontal auditory space seems reduced in early blind individuals, who are particularly better than sighted individuals at localizing sounds coming from the peripheral space. Currently, it is not clear to what extent this bias in the auditory space is a general phenomenon or if it applies only to spatial processing (i.e. sound localization). In our approach we compared the performance of early blind participants with that of sighted subjects during a frequency discrimination task with sounds originating either from frontal or peripheral locations. Results showed that early blind participants discriminated faster than sighted subjects both peripheral and frontal sounds. In addition, sighted subjects were faster at discriminating frontal sounds than peripheral ones, whereas early blind participants showed equal discrimination speed for frontal and peripheral sounds. We conclude that the spatial bias observed in sighted subjects reflects an unbalance in the spatial distribution of auditory attention resources that is induced by visual experience. PMID:24378238

  15. A Contaminant Ice Visualization Experiment in a Glass Pulse Tube

    NASA Technical Reports Server (NTRS)

    Hall, J. L.; Ross, R. G., Jr.; Le, A. K.

    2000-01-01

    Results are presented from pulse tube experiments designed to investigate the effect of 400 parts per million water vapor contamination of the helium working gas. The experiments were conducted in a glass pulse tube to enable visualization of ice formation on internal surfaces. Photographs of this ice formation were taken along with simultaneous coldtip temperature and compressor power measurements. Four types of regenerator elements were tested in various combinations: 200- and 400-mesh stainless steel screens, 1.6 mm diameter glass beads, and 1.6 mm thick perforated plastic plates. Internal spacers were also used to provide clear fields of view into the regenerator stack. Substantial water-ice formation was observed at the cold end of the regenerator and on the inside wall of pulse tube; it appeared to be highly porous, like snow, and was seen to accumulate only in a very localized region at the coldest end, despite changing the cold tip temperature across a range of 150 to 235 K. Ice formation degraded pulse tube thermal performance only in cases where screen regenerators were used at the regenerator cold end. It was concluded that flow blockage was the mechanism by which contaminants affected performance; coarse regenerator elements were largely immune over the tested time scale of a few days. Substantially reduced ice formation and minimal performance loss were also observed in repeated tests where the contaminated gas was reused after warming up and melting of the accumulated internal ice. Significant adsorption of the liquid water onto the regenerator was inferred, a process that depleted the gas phase concentration of water.

  16. 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,…

  17. Tobias Mayer--experiments on visual acuity (1755).

    PubMed

    Scheerer, E

    1987-01-01

    The pioneering experimental work of Tobias Mayer (1723-1762) on visual acuity, published in 1755 in Latin, is presented in English translation. Mayer distinguished between two kinds of visual acuity, the one (30 arc sec) for single objects seen against a uniform background, the other (1 arc min) for more complex objects such as gratings, grids, or checkerboards. Strong illumination did not improve visual acuity. For targets seen in the light of a candle, the visual angle needed for resolution was inversely proportional to the cube root of the distance of the candle and therefore to the sixth root of 'brightness'. The historical significance of Mayer's work on visual acuity is briefly outlined. PMID:3154942

  18. How personal experiences feature in women's accounts of use of information for decisions about antenatal diagnostic testing for foetal abnormality.

    PubMed

    France, Emma F; Wyke, Sally; Ziebland, Sue; Entwistle, Vikki A; Hunt, Kate

    2011-03-01

    There has been a striking growth in the availability of health-related information based on personal experience in recent years and internet users are often drawn towards other people's stories about their health. Accounts of other people's experiences might convey social and emotional information that is not otherwise available but little is known about how it is used or the implications of its use in practice. This paper examines how people refer to information about other people's experiences when accounting for decisions about antenatal diagnostic testing for foetal abnormality. We conducted a secondary analysis of 37 qualitative interviews undertaken across the UK with 36 women and nine of their male partners (eight couples were interviewed together) who talked about diagnostic testing for foetal abnormality in 55 pregnancies. When describing their decisions, respondents referred to examples of knowledge gleaned from their own and other individuals' experiences as well as information based on biomedical or clinical-epidemiological research (usually about the probabilities of having a child affected by health problems or the probability of diagnostic tests causing miscarriage). Both forms of knowledge were employed in people's accounts to illustrate the legitimacy and internal coherence of decisions taken. The analysis demonstrates the personally idiosyncratic ways that people reflect on and incorporate different types of information to add meaning to abstract ideas about risk, to imagine the consequences for their own lives and to help them to make sense of the decisions they faced. PMID:21257248

  19. Effect of visual experience on tubulin synthesis during a critical period of visual cortex development in the hooded rat.

    PubMed

    Cronly-Dillon, J; Perry, G W

    1979-08-01

    1. In some species, restriction of visual experience in early life may affect normal functional development of visual cortical cells. The purpose of the present study was to determine if visual deprivation during post-natal development in the hooded rat also affects the production in brain cells of certain molecular components such as tubulin, that are needed for growth and maintenance of synapses and neurites. 2. Norwegian black hooded rats were reared under a variety of conditions of visual deprivation. At various stages of development the animals were killed and the rate of synthesis of tubulin in visual and motor cortex determined. Tritiated colchicine was used to assay tubulin and L-[14C]leucine injected into the brain ventricles 2 hr before death was used to measure rate of tubulin synthesis. 3. In rats reared in normal light there is a marked elevation in visual cortex tubulin synthesis that spans the period from eye-opening (13 days) until approximately 35 days. This elevation in tubulin synthesis is absent in animals reared in darkness from birth or deprived of pattern vision by eyelid suture. Also the effect of visual deprivation on tubulin synthesis was specifically confined to visual cortex and was not found for the motor cortex. Similarly, the incorporation of L-[14C]leucine into total protein in visual cortex was unaffected by dark rearing. Hence the stimulation of tubulin synthesis by visual experience in rat visual cortex is not attributable to a general non-specific stimulation of protein synthesis. 4. Rats that were dark-reared from birth and then exposed to a lighted environment for 24 hr during a certain critical period that extends from eye-opening (13 days) until approximately 35 days, displayed a significant increase in visual cortex tubulin rats that were brought into the light later than 35 days showed no significant increase in tubulin synthesis when compared with their continuously dark-rearer controls. 5. It is suggested that the number

  20. Visual scanpath abnormalities in 22q11.2 deletion syndrome: is this a face specific deficit?

    PubMed

    McCabe, Kathryn; Rich, Dominique; Loughland, Carmel Maree; Schall, Ulrich; Campbell, Linda Elisabet

    2011-09-30

    People with 22q11.2 deletion syndrome (22q11DS) have deficits in face emotion recognition. However, it is not known whether this is a deficit specific to faces, or represents maladaptive information processing strategies to complex stimuli in general. This study examined the specificity of face emotion processing deficits in 22q11DS by exploring recognition accuracy and visual scanpath performance to a Faces task compared to a Weather Scene task. Seventeen adolescents with 22q11DS (11=females, age=17.4) and 18 healthy controls (11=females, age=17.7) participated in the study. People with 22q11DS displayed an overall impoverished scanning strategy to face and weather stimuli alike, resulting in poorer accuracy across all stimuli for the 22q11DS participants compared to controls. While the control subjects altered their information processing in response to faces, a similar change was not present in the 22q11DS group indicating different visual scanpath strategies to identify category within each of the tasks, of which faces appear to represent a particularly difficult subcategory. To conclude, while this study indicates that people with 22q11DS have a general visual processing deficit, the lack of strategic change between tasks suggest that the 22q11DS group did not adapt to the change in stimuli content as well as the controls, indicative of cognitive inflexibility rather than a face specific deficit. PMID:21831452

  1. RESEARCH PROJECT -- UNIVERSITY OF TEXAS FLOW VISUALIZATION EXPERIMENTS (SUBSURFACE PROTECTION AND REMEDIATION DIVISION, NRMRL)

    EPA Science Inventory

    A set of flow visualization experiments were conducted to support work on the development of Version 2.0 of the Hydrocarbon Spill Screening Model (HSSM). The two-dimensional flow visualization experiments indicate how the oil is distributed in the vadose zone and capillary fring...

  2. 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…

  3. 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…

  4. 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.…

  5. Abnormal development of sensory-motor, visual temporal and parahippocampal cortex in children with learning disabilities and borderline intellectual functioning

    PubMed Central

    Baglio, Francesca; Cabinio, Monia; Ricci, Cristian; Baglio, Gisella; Lipari, Susanna; Griffanti, Ludovica; Preti, Maria G.; Nemni, Raffaello; Clerici, Mario; Zanette, Michela; Blasi, Valeria

    2014-01-01

    Borderline intellectual functioning (BIF) is a condition characterized by an intelligence quotient (IQ) between 70 and 85. BIF children present with cognitive, motor, social, and adaptive limitations that result in learning disabilities and are more likely to develop psychiatric disorders later in life. The aim of this study was to investigate brain morphometry and its relation to IQ level in BIF children. Thirteen children with BIF and 14 age- and sex-matched typically developing (TD) children were enrolled. All children underwent a full IQ assessment (WISC-III scale) and a magnetic resonance (MR) examination including conventional sequences to assess brain structural abnormalities and high resolution 3D images for voxel-based morphometry analysis. To investigate to what extent the group influenced gray matter (GM) volumes, both univariate and multivariate generalized linear model analysis of variance were used, and the varimax factor analysis was used to explore variable correlations and clusters among subjects. Results showed that BIF children, compared to controls have increased regional GM volume in bilateral sensorimotor and right posterior temporal cortices and decreased GM volume in the right parahippocampal gyrus. GM volumes were highly correlated with IQ indices. The present work is a case study of a group of BIF children showing that BIF is associated with abnormal cortical development in brain areas that have a pivotal role in motor, learning, and behavioral processes. Our findings, although allowing for little generalization to the general population, contribute to the very limited knowledge in this field. Future longitudinal MR studies will be useful in verifying whether cortical features can be modified over time even in association with rehabilitative intervention. PMID:25360097

  6. Abnormal eating attitudes and sexual abuse experiences in Turkish university women.

    PubMed

    Elal, G; Sabol, E; Slade, P

    2004-09-01

    The aim of this study was to examine the direct and indirect relationship between abnormal eating attitudes and sexual abuse. The subject sample comprised 532 female Turkish undergraduate and nursing students in Istanbul. The Eating Attitudes Test (EAT), Sexual Abuse Questionnaire, the Setting Conditions for Anorexia Nervosa Scale, the Positive and Negative Perfectionism Scale and the Need for Control Scale (NCS) were the instruments of the study. The results showed that sexual abuse has a direct effect on EAT-Bulimia but not on EAT-Dieting. It also has some indirect effects on both of these through its effects on family functioning. Perfectionism, on the other hand, was independently linked with both EAT-Dieting and EAT-Bulimia but was not associated with sexual abuse. PMID:15656010

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

    PubMed

    Ohshiro, Tomokazu; Hussain, Shaista; Weliky, Michael

    2011-10-01

    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

  8. 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

  9. Visual Experience Shapes Orthographic Representations in the Visual Word Form Area.

    PubMed

    Wimmer, Heinz; Ludersdorfer, Philipp; Richlan, Fabio; Kronbichler, Martin

    2016-09-01

    Current neurocognitive research suggests that the efficiency of visual word recognition rests on abstract memory representations of written letters and words stored in the visual word form area (VWFA) in the left ventral occipitotemporal cortex. These representations are assumed to be invariant to visual characteristics such as font and case. In the present functional MRI study, we tested this assumption by presenting written words and varying the case format of the initial letter of German nouns (which are always capitalized) as well as German adjectives and adverbs (both usually in lowercase). As evident from a Word Type × Case Format interaction, activation in the VWFA was greater to words presented in unfamiliar case formats relative to familiar case formats. Our results suggest that neural representations of written words in the VWFA are not fully abstract and still contain information about the visual format in which words are most frequently perceived. PMID:27435995

  10. Visual Experience Shapes Orthographic Representations in the Visual Word Form Area

    PubMed Central

    Wimmer, Heinz; Ludersdorfer, Philipp; Richlan, Fabio; Kronbichler, Martin

    2016-01-01

    Current neurocognitive research suggests that the efficiency of visual word recognition rests on abstract memory representations of written letters and words stored in the visual word form area (VWFA) in the left ventral occipitotemporal cortex. These representations are assumed to be invariant to visual characteristics such as font and case. In the present functional MRI study, we tested this assumption by presenting written words and varying the case format of the initial letter of German nouns (which are always capitalized) as well as German adjectives and adverbs (both usually in lowercase). As evident from a Word Type × Case Format interaction, activation in the VWFA was greater to words presented in unfamiliar case formats relative to familiar case formats. Our results suggest that neural representations of written words in the VWFA are not fully abstract and still contain information about the visual format in which words are most frequently perceived. PMID:27435995

  11. Women with abnormal screening mammography lost to follow-up: An experience from Taiwan.

    PubMed

    Kuo, Chia-Sheng; Chen, Guan-Ru; Hung, Shou-Hung; Liu, Yi-Lien; Huang, Kuo-Chin; Cheng, Shao-Yi

    2016-06-01

    Breast cancer has the highest incidence among all cancers for women in Taiwan. The current screening policy in Taiwan suggested a biennial mammography for all women 40 to 69 years of age. A recommendation for additional testing is recommended for women with a BI-RADS result of 0 or 4; a request made via postal mail. Approximately 20% of high-risk patients do not receive additional follow-up. Therefore, we aimed to explore the causes of these patients being lost to follow-up, despite an abnormal mammogram. Two questionnaires were designed separately according to the conceptual framework of the Health Belief Model. Study participants, women who received a screening mammography at the National Taiwan University Hospital in 2011 with a BI-RAD of 0 or 4, were interviewed via telephone. The dependent variable was receipt of follow-up or not. The analyses were performed by using χ tests and logistic regression models. In total, 528 women were enrolled in the study: 51.2% in BI-RADS 0 group and 56.6% in BI-RADS 4, respectively. In the BI-RADS 0 group, those patients who received a follow-up examination cited the most likely causes to be physician suggestion, health implications, and concerns regarding breast cancer. Patients who did not receive a follow-up examination cited a lack of time and a perception of good personal health as primary reasons. In the BI-RADS 4 group, those patients who received a follow-up examination cited the physician's recommendation and a recognition of the importance of follow-up examinations. Patients who did not receive a follow-up examination cited having received follow-up at another hospital and a desire for a second opinion. In the BI-RADS 0 group, multivariate analysis showed that patients with higher scores in the "perceived benefits" domain were statistically more likely to receive a follow-up examination. There was no significant difference in perceived threats, perceived barriers, action cues, or self-efficacy between groups. We

  12. Auditory processing abnormalities in schizotypal personality disorder: An fMRI experiment using tones of deviant pitch and duration

    PubMed Central

    Dickey, Chandlee C.; Morocz, Istvan A.; Niznikiewicz, Margaret A.; Voglmaier, Martina; Toner, Sarah; Khan, Usman; Dreusicke, Mark; Yoo, Seung-Schik; Shenton, Martha E.; McCarley, Robert W.

    2011-01-01

    Background One of the cardinal features of schizotypal personality disorder (SPD) is language abnormalities. The focus of this study was to determine whether or not there are also processing abnormalities of pure tones differing in pitch and duration in SPD. Methods Thirteen neuroleptic-naïve male subjects met full criteria for SPD and were group-matched on age and parental socioeconomic status to 13 comparison subjects. Verbal learning was measured with the California Verbal Learning Test. Heschl’s gyrus volumes were measured using structural MRI. Whole-brain fMRI activation patterns in an auditory task of listening to tones including pitch and duration deviants were compared between SPD and control subjects. In a second and separate ROI analysis we found that peak activation in superior temporal gyrus (STG), Brodmann Areas 41 and 42, was correlated with verbal learning and clinical measures derived from the SCID-II interview. Results In the region of the STG, SPD subjects demonstrated more activation to pitch deviants bilaterally (p<0.001); and to duration deviants in the left hemisphere (p=0.005) (two-sample t). SPD subjects also showed more bilateral parietal cortex activation to duration deviants. In no region did comparison subjects activate more than SPD subjects in either experiment. Exploratory correlations for SPD subjects suggest a relationship between peak activation on the right for deviant tones in the pitch experiment with odd speech and impaired verbal learning. There was no difference between groups on Heschl’s gyrus volume. Conclusions These data suggest that SPD subjects have inefficient or hyper-responsive processing of pure tones both in terms of pitch and duration deviance that is not attributable to smaller Heschl’s gyrus volumes. Finally, these auditory processing abnormalities may have significance for the odd speech heard in some SPD subjects and downstream language and verbal learning deficits. PMID:18555666

  13. Experience-dependent emergence of fine-scale networks in visual cortex.

    PubMed

    Ishikawa, Ayako Wendy; Komatsu, Yukio; Yoshimura, Yumiko

    2014-09-10

    Visual cortical neurons selectively respond to particular features of visual stimuli and this selective responsiveness emerges from specific connectivity in the cortex. Most visual response properties are basically established by eye opening and are thereafter modified or refined by visual experience based on activity-dependent synaptic modifications during an early postnatal period. Visual deprivation during this period impairs development of visual functions, such as visual acuity. We previously demonstrated that fine-scale networks composed of a population of interconnected layer 2/3 (L2/3) pyramidal neurons receiving common inputs from adjacent neurons are embedded in a small area in rat visual cortex. We suggested that this network could be a functional unit for visual information processing. In this study, we investigated the effects of early visual experience on the development of fine-scale networks and individual synaptic connections in rat visual cortical slices. We used two kinds of deprivation, binocular deprivation and dark rearing, which allowed visual inputs with only diffuse light and no visual input, respectively. The probability and strength of excitatory connections to L2/3 pyramidal cells increased during the 2 weeks after eye opening, and these changes were prevented by dark rearing, but not binocular deprivation. Fine-scale networks were absent just after eye opening and established during the following 2 weeks in rats reared with normal visual experience, but not with either type of deprivation. These results indicate that patterned vision is required for the emergence of the fine-scale network, whereas diffuse light stimulation is sufficient for the maturation of individual synapses. PMID:25209295

  14. Combination of blood oxygen level–dependent functional magnetic resonance imaging and visual evoked potential recordings for abnormal visual cortex in two types of amblyopia

    PubMed Central

    Wang, Xinmei; Cui, Dongmei; Zheng, Ling; Yang, Xiao; Yang, Hui

    2012-01-01

    Purpose To elucidate the different neuromechanisms of subjects with strabismic and anisometropic amblyopia compared with normal vision subjects using blood oxygen level–dependent functional magnetic resonance imaging (BOLD-fMRI) and pattern-reversal visual evoked potential (PR-VEP). Methods Fifty-three subjects, age range seven to 12 years, diagnosed with strabismic amblyopia (17 cases), anisometropic amblyopia (20 cases), and normal vision (16 cases), were examined using the BOLD-fMRI and PR-VEP of UTAS-E3000 techniques. Cortical activation by binocular viewing of reversal checkerboard patterns was examined in terms of the calcarine region of interest (ROI)-based and spatial frequency–dependent analysis. The correlation of cortical activation in fMRI and the P100 amplitude in VEP were analyzed using the SPSS 12.0 software package. Results In the BOLD-fMRI procedure, reduced areas and decreased activation levels were found in Brodmann area (BA) 17 and other extrastriate areas in subjects with amblyopia compared with the normal vision group. In general, the reduced areas mainly resided in the striate visual cortex in subjects with anisometropic amblyopia. In subjects with strabismic amblyopia, a more significant cortical impairment was found in bilateral BA 18 and BA 19 than that in subjects with anisometropic amblyopia. The activation by high-spatial-frequency stimuli was reduced in bilateral BA 18 and 19 as well as BA 17 in subjects with anisometropic amblyopia, whereas the activation was mainly reduced in BA 18 and BA 19 in subjects with strabismic amblyopia. These findings were further confirmed by the ROI-based analysis of BA 17. During spatial frequency–dependent VEP detection, subjects with anisometropic amblyopia had reduced sensitivity for high spatial frequency compared to subjects with strabismic amblyopia. The cortical activation in fMRI with the calcarine ROI-based analysis of BA 17 was significantly correlated with the P100 amplitude in VEP

  15. 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. PMID:26162617

  16. Not Your Mother's View: The Dynamics of Toddler Visual Experience

    ERIC Educational Resources Information Center

    Smith, Linda B.; Yu, Chen; Pereira, Alfredo F.

    2011-01-01

    Human toddlers learn about objects through second-by-second, minute-by-minute sensory-motor interactions. In an effort to understand how toddlers' bodily actions structure the visual learning environment, mini-video cameras were placed low on the foreheads of toddlers, and for comparison also on the foreheads of their parents, as they jointly…

  17. Varieties of Visual Experience; Art as Image and Idea.

    ERIC Educational Resources Information Center

    Feldman, Edmund Burke, Ed.

    Beginning with a discussion of the functions of art, the author traces the various connections between visual forms and the personal, social, and physical dimensions of everyday life. These are examined in the light of the impact art has on psychological expression, social description, the communication of ideology, the design of useful objects,…

  18. The Dynamic Discourse of Visual Literacy in Experience Design

    ERIC Educational Resources Information Center

    Search, Patricia

    2009-01-01

    Traditionally, people have used perspectives of space and time to define a sense of place and personal identity. Western cultures interpret place and time as static entities. In interactive multimedia computing, visual literacy defines new dimensions in communication that are reshaping traditional Western concepts of place and time. Experience…

  19. Our Experiences with Using Visualization Tools in Teaching Calculus.

    ERIC Educational Resources Information Center

    Kowalczyk, Robert E.; Hausknecht, Adam O.

    This paper describes two uses of the software package TEMATH (Tools for Exploring Mathematics) with calculus students: (1) as a demonstration tool in the classroom to visually explore with students the many mathematical models introduced in a first year calculus course; and (2) as a part of a lab where students use a set of laboratory explorations…

  20. Wearing weighted backpack dilates subjective visual duration: the role of functional linkage between weight experience and visual timing.

    PubMed

    Jia, Lina; Shi, Zhuanghua; Feng, Wenfeng

    2015-01-01

    Bodily state plays a critical role in our perception. In the present study, we asked the question whether and how bodily experience of weights influences time perception. Participants judged durations of a picture (a backpack or a trolley bag) presented on the screen, while wearing different weight backpacks or without backpack. The results showed that the subjective duration of the backpack picture was dilated when participants wore a medium weighted backpack relative to an empty backpack or without backpack, regardless of identity (e.g., color) of the visual backpack. However, the duration dilation was not manifested for the picture of trolley bag. These findings suggest that weight experience modulates visual duration estimation through the linkage between the wore backpack and to-be-estimated visual target. The congruent action affordance between the wore backpack and visual inputs plays a critical role in the functional linkage between inner experience and time perception. We interpreted our findings within the framework of embodied time perception. PMID:26441748

  1. Wearing weighted backpack dilates subjective visual duration: the role of functional linkage between weight experience and visual timing

    PubMed Central

    Jia, Lina; Shi, Zhuanghua; Feng, Wenfeng

    2015-01-01

    Bodily state plays a critical role in our perception. In the present study, we asked the question whether and how bodily experience of weights influences time perception. Participants judged durations of a picture (a backpack or a trolley bag) presented on the screen, while wearing different weight backpacks or without backpack. The results showed that the subjective duration of the backpack picture was dilated when participants wore a medium weighted backpack relative to an empty backpack or without backpack, regardless of identity (e.g., color) of the visual backpack. However, the duration dilation was not manifested for the picture of trolley bag. These findings suggest that weight experience modulates visual duration estimation through the linkage between the wore backpack and to-be-estimated visual target. The congruent action affordance between the wore backpack and visual inputs plays a critical role in the functional linkage between inner experience and time perception. We interpreted our findings within the framework of embodied time perception. PMID:26441748

  2. '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

  3. Effects of Prematurity on the Development of Contrast Sensitivity: Testing the Visual Experience Hypothesis

    PubMed Central

    Bosworth, Rain G.; Dobkins, Karen R.

    2013-01-01

    In order to investigate the effects of visual experience on early visual development, the current study compared contrast sensitivity across infants born with different levels of moderate-to-late prematurity. Here the logic is that at any given postterm age, the most premature infants will have the oldest postnatal age. Given that postnatal age is a proxy for visual experience, the visual experience hypothesis predicts that infants who are more premature, yet healthy, should have higher sensitivity. Luminance (light/dark) and chromatic (red/green) contrast sensitivities (CS) were measured in 236 healthy infants (born −10 to +2 weeks relative to due date) between 5 and 32 weeks postterm age from due date and 8 to 38 weeks postnatal from birth date. For chromatic CS, we found clear evidence that infants who were most premature within our sample had the highest sensitivity. Specifically, 4 to 10 additional weeks of visual experience, by virtue of being born early, enhanced chromatic CS. For luminance CS, similar but weaker results were seen. Here, only infants with an additional 6 to 10 weeks of visual experience, and only at later age points in development, showed enhanced sensitivity. However, CS in preterm infants was still below that of fullterm infants with equivalent postnatal age. In sum, these results suggest that chromatic CS is influenced more by prematurity (and possibly visual experience) than is luminance CS, which has implications for differential development of Parvocellular and Magnocellular pathways. PMID:23485427

  4. Transcranial Direct Current Stimulation (tDCS) of the visual cortex: a proof-of-concept study based on interictal electrophysiological abnormalities in migraine

    PubMed Central

    2013-01-01

    Background Preventive pharmacotherapy for migraine is not satisfactory because of the low efficacy/tolerability ratio of many available drugs. Novel and more efficient preventive strategies are therefore warranted. Abnormal excitability of cortical areas appears to play a pivotal role in migraine pathophysiology. Transcranial direct current stimulation (tDCS) is a non-invasive and safe technique that is able to durably modulate the activity of the underlying cerebral cortex, and is being tested in various medical indications. The results of small open studies using tDCS in migraine prophylaxis are conflicting, possibly because the optimal stimulation settings and the brain targets were not well chosen. We have previously shown that the cerebral cortex, especially the visual cortex, is hyperresponsive in migraine patients between attacks and provided evidence from evoked potential studies that this is due to a decreased cortical preactivation level. If one accepts this concept, anodal tDCS over the visual cortex may have therapeutic potentials in migraine prevention, as it is able to increase neuronal firing. Objective To study the effects of anodal tDCS on visual cortex activity in healthy volunteers (HV) and episodic migraine without aura patients (MoA), and its potentials for migraine prevention. Methods We recorded pattern-reversal visual evoked potentials (VEP) before and after a 15-min session of anodal tDCS over the visual cortex in 11 HV and 13 MoA interictally. Then 10 MoA patients reporting at least 4 attacks/month subsequently participated in a therapeutic study, and received 2 similar sessions of tDCS per week for 8 weeks as migraine preventive therapy. Results In HV as well as in MoA, anodal tDCS transiently increased habituation of the VEP N1P1 component. VEP amplitudes were not modified by tDCS. Preventive treatment with anodal tDCS turned out to be beneficial in MoA: migraine attack frequency, migraine days, attack duration and acute medication

  5. 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.

  6. Emergence of Feature-Specific Connectivity in Cortical Microcircuits in the Absence of Visual Experience

    PubMed Central

    Ko, Ho; Mrsic-Flogel, Thomas D.

    2014-01-01

    In primary visual cortex (V1), connectivity between layer 2/3 (L2/3) excitatory neurons undergoes extensive reorganization after the onset of visual experience whereby neurons with similar feature selectivity form functional microcircuits (Ko et al., 2011, 2013). It remains unknown whether visual experience is required for the developmental refinement of intracortical circuitry or whether this maturation is guided intrinsically. Here, we correlated the connectivity between V1 L2/3 neurons assayed by simultaneous whole-cell recordings in vitro to their response properties measured by two-photon calcium imaging in vivo in dark-reared mice. We found that neurons with similar responses to oriented gratings or natural movies became preferentially connected in the absence of visual experience. However, the relationship between connectivity and similarity of visual responses to natural movies was not as strong in dark-reared as in normally reared mice. Moreover, dark rearing prevented the normally occurring loss of connections between visually nonresponsive neurons after eye opening (Ko et al., 2013). Therefore, our data suggest that the absence of visual input does not prevent the emergence of functionally specific recurrent connectivity in cortical circuits; however, visual experience is required for complete microcircuit maturation. PMID:25031418

  7. Older Adults with Visual Impairment: Lived Experiences and a Walking Group

    ERIC Educational Resources Information Center

    Green, Clare; Miyahara, Motohide

    2007-01-01

    The authors investigated past and present physical activities of 6 older individuals with diverse types of visual impairment who participated in a walking group. The authors identified the participants' lived experiences of visual impairment and physical activity through interviews and assessed their current activity levels by using pedometers.…

  8. Shape Recovery: A Visual Method for Evaluation of Information Retrieval Experiments.

    ERIC Educational Resources Information Center

    Rorvig, Mark; Fitzpatrick, Steven

    2000-01-01

    The method described permits visual analysis of information retrieval (IR) experiment results in classic control and treatment group protocols. It is an additional analysis technique for the evaluation of IR procedures that may be conducted within the rich terrain of human visual acuity, supported by two well-known statistical measures. (Contains…

  9. Subjective evaluation of user experience in interactive 3D visualization in a medical context

    NASA Astrophysics Data System (ADS)

    Tourancheau, Sylvain; Sjöström, Mårten; Olsson, Roger; Persson, Anders; Ericson, Thomas; Rudling, Johan; Norén, Bengt

    2012-02-01

    New display technologies enable the usage of 3D-visualization in a medical context. Even though user performance seems to be enhanced with respect to 2D thanks to the addition of recreated depth cues, human factors, and more particularly visual comfort and visual fatigue can still be a bridle to the widespread use of these systems. This study aimed at evaluating and comparing two different 3D visualization systems (a market stereoscopic display, and a state-of-the-art multi-view display) in terms of quality of experience (QoE), in the context of interactive medical visualization. An adapted methodology was designed in order to subjectively evaluate the experience of users. 14 medical doctors and 15 medical students took part in the experiment. After solving different tasks using the 3D reconstruction of a phantom object, they were asked to judge their quality of the experience, according to specific features. They were also asked to give their opinion about the influence of 3D-systems on their work conditions. Results suggest that medical doctors are opened to 3D-visualization techniques and are confident concerning their beneficial influence on their work. However, visual comfort and visual fatigue are still an issue of 3D-displays. Results obtained with the multi-view display suggest that the use of continuous horizontal parallax might be the future response to these current limitations.

  10. Emergence of feature-specific connectivity in cortical microcircuits in the absence of visual experience.

    PubMed

    Ko, Ho; Mrsic-Flogel, Thomas D; Hofer, Sonja B

    2014-07-16

    In primary visual cortex (V1), connectivity between layer 2/3 (L2/3) excitatory neurons undergoes extensive reorganization after the onset of visual experience whereby neurons with similar feature selectivity form functional microcircuits (Ko et al., 2011, 2013). It remains unknown whether visual experience is required for the developmental refinement of intracortical circuitry or whether this maturation is guided intrinsically. Here, we correlated the connectivity between V1 L2/3 neurons assayed by simultaneous whole-cell recordings in vitro to their response properties measured by two-photon calcium imaging in vivo in dark-reared mice. We found that neurons with similar responses to oriented gratings or natural movies became preferentially connected in the absence of visual experience. However, the relationship between connectivity and similarity of visual responses to natural movies was not as strong in dark-reared as in normally reared mice. Moreover, dark rearing prevented the normally occurring loss of connections between visually nonresponsive neurons after eye opening (Ko et al., 2013). Therefore, our data suggest that the absence of visual input does not prevent the emergence of functionally specific recurrent connectivity in cortical circuits; however, visual experience is required for complete microcircuit maturation. PMID:25031418

  11. GABAA agonist reduces visual awareness: a masking-EEG experiment.

    PubMed

    van Loon, Anouk M; Scholte, H Steven; van Gaal, Simon; van der Hoort, Björn J J; Lamme, Victor A F

    2012-04-01

    Consciousness can be manipulated in many ways. Here, we seek to understand whether two such ways, visual masking and pharmacological intervention, share a common pathway in manipulating visual consciousness. We recorded EEG from human participants who performed a backward-masking task in which they had to detect a masked figure form its background (masking strength was varied across trials). In a within-subject design, participants received dextromethorphan (a N-methyl-d-aspartate receptor antagonist), lorazepam (LZP; a GABA(A) receptor agonist), scopolamine (a muscarine receptor antagonist), or placebo. The behavioral results show that detection rate decreased with increasing masking strength and that of all the drugs, only LZP induced a further decrease in detection rate. Figure-related ERP signals showed three neural events of interest: (1) an early posterior occipital and temporal generator (94-121 msec) that was not influenced by any pharmacological manipulation nor by masking, (2) a later bilateral perioccipital generator (156-211 msec) that was reduced by masking as well as LZP (but not by any other drugs), and (3) a late bilateral occipital temporal generator (293-387 msec) that was mainly affected by masking. Crucially, only the intermediate neural event correlated with detection performance. In combination with previous findings, these results suggest that LZP and masking both reduce visual awareness by means of modulating late activity in the visual cortex but leave early activation intact. These findings provide the first evidence for a common mechanism for these two distinct ways of manipulating consciousness. PMID:22264199

  12. 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

  13. TallyHO obese female mice experience poor reproductive outcomes and abnormal blastocyst metabolism which is reversed by metformin

    PubMed Central

    Louden, Erica D.; Luzzo, Kerri M.; Jimenez, Patricia T.; Chi, Tiffany; Chi, Maggie; Moley, Kelle H.

    2015-01-01

    Objective Obese women experience worse reproductive outcomes compared to normal weight women, specifically infertility, pregnancy loss, fetal malformations and developmental delay. The objective of this study was to use a genetic mouse model of obesity in order to recapitulate the human reproductive phenotype and further examine potential mechanisms and therapies. Methods New inbred, polygenic Type 2 diabetic TallyHO mice and age matched control C57BL/6 mice were superovulated to obtain morulae or blastocysts stage embryos which were cultured in human tubal fluid media. Deoxyglucose uptake was performed on insulin-stimulated individual blastocysts. Apoptosis was detected by confocal microscopy using TUNEL assay and Topro-3 nuclear dye. Embryos were scored for %TUNEL positive/total nuclei. AMPK activation, TNFα expression, and adiponectin expression were analyzed by western immunoblot and confocal immunofluorescent microscopy. Lipid accumulation was assayed by Bodipy. Finally all measured parameters were compared between TallyHO mice in morulaes cultured to blastocyst embryos in either human tubal fluid (HTF) media or HTF with 25ug/ml metformin added. Results TallyHo mice developed whole body abnormal insulin tolerance, decreased litter number and increased NEFA. Blastocysts demonstrated increased apoptosis, decreased insulin sensitivity, and decreased activation of AMP activated protein-kinase (AMPK). As a possible cause of the insulin resistance/abnormal P-AMPK, we found that Tumor necrosis Factor (TNFα) expression and lipid accumulation as detected by BODIPY were increased in TallyHO blastocysts and adiponectin was decreased. Culturing TallyHO morulae with the AMPK activator, metformin lead to a reversal of all abnormal findings, including increased p-AMPK, improved insulin-stimulated glucose uptake and normalization of lipid accumulation. Conclusions Women with obesity and insulin resistance experience poor pregnancy outcomes. Previously we have shown in mouse

  14. Seeing the World Dimly: The Impact of Early Visual Deficits on Visual Experience in Schizophrenia

    PubMed Central

    Kantrowitz, Joshua T.; Butler, Pamela D.; Schecter, Isaac; Silipo, Gail; Javitt, Daniel C.

    2009-01-01

    Deficits in early visual processing are well documented in schizophrenia, using methods such as contrast sensitivity. Higher, integrative stages of functioning, such as susceptibility to visual illusions, have been evaluated less extensively. For example, patients show increased susceptibility to (ie, are more easily affected by) the Muller-Lyer illusion but decreased susceptibility (ie, are less easily affected by) to stereopsis based upon binocular disparity. The basis for pattern of illusion response and interaction between sensory and integrative stages of processing, however, is unclear. We tested a group of 38 patients and 28 control subjects in contrast sensitivity, the Muller-Lyer and Poggendorff illusions, as well as a subgroup in stereopsis and the Ponzo illusion, Sander parallelogram, and Hermann grid illusions. We predicted that patients would be more susceptible to tests that become more apparent with increased contrast (Muller-Lyer illusion), less susceptible to tests that become less apparent with increased contrast (stereopsis, Ponzo illusion, Hermann grid), and equally susceptible to contrast-insensitive tests (Poggendorff illusion). Additionally, the Hermann grid was tested at varying levels of contrast. Patients demonstrated significant deficits in contrast sensitivity, especially to brief, low spatial frequency stimuli, and the predicted differential response to the tested illusions. Additionally, poor performance on stereopsis and the Hermann grid significantly correlated with decreased contrast sensitivity (all P’s <.01). Muller-Lyer illusion and stereopsis performance were also inversely related (P < .01). This study replicates and expands upon previous findings with visual illusions. Our results offer a unifying explanation for disparate studies and suggest that deficits in early sensory gain affect subsequent integrative processes. PMID:19793795

  15. Early visual experience influences behavioral lateralization in the guppy.

    PubMed

    Dadda, Marco; Bisazza, Angelo

    2016-09-01

    Individual differences in lateralization of cognitive functions characterize both humans and non-human species. Genetic factors can account for only a fraction of the variance observed and the source of individual variation in laterality remains in large part elusive. Various environmental factors have been suggested to modulate the development of lateralization, including asymmetrical stimulation of the sensory system during ontogeny. In this study, we raised newborn guppies in an asymmetric environment to test the hypothesis that early left-right asymmetries in visual input may affect the development of cerebral asymmetries. Each fish was raised in an impoverished environment but could voluntarily observe a complex scene in a nearby compartment containing a group of conspecifics. Using asymmetric structures, we allowed some subjects to observe the complex scene with the right eye, others with the left eye, and control fish with both eyes. Among asymmetrically stimulated fish, the mirror test revealed eye dominance congruent with the direction of asymmetric stimulation, while controls showed no left-right laterality bias. Interestingly, asymmetric exposure to social stimuli also affected another aspect of visual lateralization-eye preference for scrutinizing a potential predator-but did not influence a measure of motor asymmetry. As the natural environment of guppies is fundamentally asymmetrical, we suggest that unequal left-right stimulation is a common occurrence in developing guppies and may represent a primary source of individual variation in lateralization as well as an efficient mechanism for producing laterality phenotypes that are adapted to local environmental conditions. PMID:27215573

  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. 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. PMID:26183014

  18. 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

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

    PubMed

    Bock, Andrew S; Binda, Paola; Benson, Noah C; Bridge, Holly; Watkins, Kate E; Fine, Ione

    2015-09-01

    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

  20. Visualization of Growth Curve Data from Phenotype MicroarrayExperiments

    SciTech Connect

    Jacobsen, Janet S.; Joyner, Dominique C.; Borglin, Sharon E.; Hazen, Terry C.; Arkin, Adam P.; Bethel, E. Wes

    2007-04-19

    Phenotype microarrays provide a technology to simultaneouslysurvey the response of an organism to nearly 2,000 substrates, includingcarbon, nitrogen and potassium sources; varying pH; varying saltconcentrations; and antibiotics. In order to more quickly and easily viewand compare the large number of growth curves produced by phenotypemicroarray experiments, we have developed software to produce and displaycolor images, each of which corresponds to a set of 96 growth curves.Using color images to represent growth curves data has proven to be avaluable way to assess experiment quality, compare replicates, facilitatecomparison of the responses of different organisms, and identifysignificant phenotypes. The color images are linked to traditional plotsof growth versus time, as well as to information about the experiment,organism, and substrate. In order to share and view information and dataproject-wide, all information, plots, and data are accessible using onlya Web browser.

  1. The structure of experience, the nature of the visual, and type 2 blindsight.

    PubMed

    Macpherson, Fiona

    2015-03-01

    Unlike those with type 1 blindsight, people who have type 2 blindsight have some sort of consciousness of the stimuli in their blind field. What is the nature of that consciousness? Is it visual experience? I address these questions by considering whether we can establish the existence of any structural-necessary-features of visual experience. I argue that it is very difficult to establish the existence of any such features. In particular, I investigate whether it is possible to visually, or more generally perceptually, experience form or movement at a distance from our body, without experiencing colour. The traditional answer, advocated by Aristotle, and some other philosophers, up to and including the present day, is that it is not and hence colour is a structural feature of visual experience. I argue that there is no good reason to think that this is impossible, and provide evidence from four cases-sensory substitution, achomatopsia, phantom contours and amodal completion-in favour of the idea that it is possible. If it is possible then one important reason for rejecting the idea that people with type 2 blindsight do not have visual experiences is undermined. I suggest further experiments that could be done to help settle the matter. PMID:25481513

  2. Mountain Plains Learning Experience Guide: Marketing. Course: Visual Merchandising.

    ERIC Educational Resources Information Center

    Preston, T.; Egan, B.

    One of thirteen individualized courses included in a marketing curriculum, this course covers the steps to be followed in planning, constructing, and evaluating the effectiveness of merchandise displays. The course is comprised of one unit, General Merchandise Displays. The unit begins with a Unit Learning Experience Guide that gives directions…

  3. Leading and Learning as a Transcultural Experience: A Visual Account

    ERIC Educational Resources Information Center

    Schratz, Michael

    2009-01-01

    Leaving one's own territory in research by taking part in an international project is like learning a new language: it's not just learning a new vocabulary and grammar, but is a total human experience which is best learnt in everyday activity. Social scientists like Jean Lave argued that "knowledge-in-practice, constituted in the settings of…

  4. What Do We See?: Extending Understanding of Visual Experience in the Art Therapy Encounter

    ERIC Educational Resources Information Center

    Fenner, Patricia

    2012-01-01

    Visual experience and meaning making in art therapy constitute more than looking at the image created. Clients and therapists utilize the environment of therapy in ways that have been hitherto unrecognized. This article presents a key finding from an art-based study of the experience of the art therapy room from the perspectives of client and…

  5. 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…

  6. Designing, Visualizing, and Discussing Algorithms within a CS 1 Studio Experience: An Empirical Study

    ERIC Educational Resources Information Center

    Hundhausen, Christopher D.; Brown, Jonathan L.

    2008-01-01

    Within the context of an introductory CS1 unit on algorithmic problem-solving, we are exploring the pedagogical value of a novel active learning activity--the "studio experience"--that actively engages learners with algorithm visualization technology. In a studio experience, student pairs are tasked with (a) developing a solution to an algorithm…

  7. 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 =…

  8. Creating and Using Tactile Experience Books for Young Children with Visual Impairments.

    ERIC Educational Resources Information Center

    Lewis, Sandra; Tolla, Joan

    2003-01-01

    This article explores how tactile experience books can be used to ensure that young children with visual impairments learn to read. It discusses making tactile experience books by collecting artifacts and gluing them to cardboard pages, and the benefits of tactile books. Descriptions of two tactile books are provided. (Contains references.) (CR)

  9. Experiments at Scale with In-Situ Visualization Using ParaView/Catalyst in RAGE

    SciTech Connect

    Kares, Robert John

    2014-10-31

    In this paper I describe 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 on the Cielo supercomputer at Los Alamos. The detailed procedures for the creation of the visualizations using ParaView/Catalyst are discussed and several images sequences from the ICF simulation problem produced with the in-situ method are presented. My impressions and conclusions concerning the use of the in-situ visualization method in RAGE are discussed.

  10. Evaluation of quality of experience in interactive 3D visualization: methodology and results

    NASA Astrophysics Data System (ADS)

    Tourancheau, Sylvain; Sjöström, Mårten; Olsson, Roger; Persson, Anders; Ericson, Thomas

    2012-03-01

    Human factors are of high importance in 3D visualization, but subjective evaluation of 3D displays is not easy because of a high variability among users. This study aimed to evaluate and compare two different 3D visualization systems (a market stereoscopic display, and a state-of-the-art multi-view display) in terms of user performance and quality of experience (QoE), in the context of interactive visualization. An adapted methodology has been designed in order to focus on 3D differences and to reduce the influence of all other factors. Thirty-six subjects took part in an experiment during which they were asked to judge the quality of their experience, according to specific features. Results showed that a scene understanding and precision was significantly better on the multi-view display. Concerning the quality of experience, visual comfort was judged significantly better on the multi-view display and visual fatigue was reported by 52% of the subjects on the stereoscopic display. This study has permitted to identify some factors influencing QoE such as prior experience and stereopsis threshold.

  11. Brain responses to repeated visual experience among low and high sensation seekers: role of boredom susceptibility

    PubMed Central

    Jiang, Yang; Lianekhammy, Joann; Lawson, Adam; Guo, Chunyan; ynam, Donald; Joseph, Jane E.; Gold, Brian T.; Kelly, Thomas H.

    2009-01-01

    To better understand individual differences in sensation seeking and its components, including boredom susceptibility and experience seeking, we examined brain responses of high and low sensation seekers during repeated visual experience. Individuals scoring in the top and bottom quartiles from a college-aged population on the Brief Sensation-Seeking Scale (BSSS) participated in an event-related potentials (ERPs) experiment. Line drawings of common objects were randomly intermixed and presented 1–3 times. Sixty-four channel ERP responses were recorded while participants classified items as “man-made” or “not man-made” in a repetition priming task. The two groups showed different ERP responses at frontal electrode sites after seeing a visual stimulus for 400–800 ms. The frontal late positive components (LPC) showed different habituation of ERP responses to new and studied repeated objects between high and low sensation seekers. Source localization analysis (LORETA) indicated that during visual stimulus adaptation the left ventral pre-frontal cortex showed lack of frontal involvement among high sensation seekers. Furthermore, frontal LPC latencies during repeated visual exposure correlated with boredom susceptibility and experience seeking subscales. The distinct profiles of brain responses to repeated visual experience in high and low sensation seekers provide evidence that individual differences in neural adaptation can be linked to personality dimensions. PMID:19560906

  12. Mobility Experience of Persons with Visual Impairments in Indian Railway Station Environments.

    PubMed

    Raheja, Gaurav; Tyagi, Megha

    2016-01-01

    Mobility for persons with visual impairments in Indian railway stations poses multidimensional challenges for access to an inclusive travel experience. India is a home to about twenty million persons with diverse disabilities out of which about five million are persons with visual impairments. Diversity of passenger movements on a railway station including persons with visual impairments requires a Universal Design approach to respond to the accessibility issues in these contexts. This research study is based on a series of live on-site experiences conducted along with persons with visual impairments at New Delhi Railway Station. It also includes the generic studies carried out with other diversities of railway passengers including aging, gender and diverse physical abilities. It employs research methods like ethnography, focus group interactions and trace study to develop a deeper understanding of human and spatial parameters of mobility in railway station environments. A Universal Design perspective with a holistic understanding remains critical to the foundation of this research study. While it deals in specific requirements of persons with visual impairments, it also brings an illustration of handling diversity on a railway station from a unique Indian perspective. It concludes by highlighting and reinterpreting the Universal Design India Principles integrating the needs of persons with visual impairments in railway station environments. Brief recommendation for an inclusive mobility experience on railway station forms a vital part of this grounded research study. PMID:27534355

  13. Focus of attention in systems for visual monitoring of experiments

    NASA Technical Reports Server (NTRS)

    Blank, G. E.; Martin, W. N.

    1987-01-01

    The problem of designing a computerized experiment monitoring system for use in a space station or elsewhere is examined. It is shown that the essential challenge of such a system - attaining a reasonable expected running time - can be attacked using the concept of focus of attention and by exploiting parallelism. The use of the Contract Net Protocol for the latter purpose is discussed. The use of ideas from information science to help focus a programs's efforts on those computations likely to bring results is addressed, and the incorporation of those ideas into a design in order to aid the system in deciding upon the best course of action is considered.

  14. 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.…

  15. Metacognitive sensitivity of subjective reports of decisional confidence and visual experience.

    PubMed

    Rausch, Manuel; Müller, Hermann J; Zehetleitner, Michael

    2015-09-01

    Previous studies provided contradicting results regarding metacognitive sensitivity estimated from subjective reports of confidence in comparison to subjective reports of visual experience. We investigated whether this effect of content of subjective reports is influenced by the statistical method to quantify metacognitive sensitivity. Comparing logistic regression and meta-d in a masked orientation task, a masked shape task, and a random-dot motion task, we observed metacognitive sensitivity of reports regarding decisional confidence was greater than of reports about visual experience irrespective of mathematical procedures. However, the relationship between subjective reports and the logistic transform of accuracy was often not linear, implying that logistic regression is not a consistent measure of metacognitive sensitivity. We argue that a science of consciousness would benefit from the assessment of both visual experience and decisional confidence, and recommend meta-d as measure of metacognitive sensitivity for future studies. PMID:25758187

  16. Seeing The "New Forest": A Visual Curricular Experiment

    NASA Astrophysics Data System (ADS)

    Garramone, Pariss Nicola

    In contemporary Western contexts, human interaction with and interpretation of nature is a perpetually mediated process. Understandings and engagements with natural environments are informed by and often overlaid with meanings derived from representations. In other words, representations help constitute human relationships with nature. Thus learning how representations shape human understandings and experiences of nature and the resulting social, political, and ecological impact of these mediated relationships has emerged as an important field of inquiry within environmental education. This dissertation examines how a critical, self-reflexive act of looking at photographs can challenge an individual's concepts of nature/culture, real/imaginary, and self/other. The project engages in a curricular experiment where the researcher explores how photography meditates her abstract and embodied understandings of specific natural environments. A critical, self-reflexive approach to aesthetic engagement with photographs moves beyond simply deciphering or decoding representations; it incorporates the learner's own narrative and embodied responses to the photographic representations being explored. This approach also recognizes that pedagogy has a transformative effect; both the learner and the representations being explored are transformed through the process of engagement. In this dissertation, a selection of iconic photographs of Canadian tree planting from the collection of the National Gallery of Canada are looked at: Lorraine Gilbert's (1987-2004) series "Shaping the New Forest" and Sarah Anne Johnson's (2005) work "The Tree Planting Project." The aim of this project is twofold: to unravel how these photographs construct and transform knowledge of and relationships with the environment in Canada, and to demonstrate a model of environmental inquiry that can be integrated into critical environmental education curricula.

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

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-47 Payload Specialist Mamoru Mohri, using the light impulse stimulation experiment hardware, conducts Comparative Measurement of Visual Stability in Earth and Cosmic Space (VISUAL STABILITY). The hardware is set up in the forward section of the Spacelab Japan (SLJ) science module aboard the Earth-orbiting Endeavour, Orbiter Vehicle (OV) 105. The experiment will investigate the lack of eye, head, and body coordination as a possible contributor to space adaptation syndrome (SAS). Electrodes attached to Mohri record his eye movements and neck tension as he tracks a flickering light while he is at a 45-degree angle. Mohri represents Japan's National Space Development Agency (NASDA).

  18. Beyond colour perception: auditory-visual synaesthesia induces experiences of geometric objects in specific locations.

    PubMed

    Chiou, Rocco; Stelter, Marleen; Rich, Anina N

    2013-06-01

    Our brain constantly integrates signals across different senses. Auditory-visual synaesthesia is an unusual form of cross-modal integration in which sounds evoke involuntary visual experiences. Previous research primarily focuses on synaesthetic colour, but little is known about non-colour synaesthetic visual features. Here we studied a group of synaesthetes for whom sounds elicit consistent visual experiences of coloured 'geometric objects' located at specific spatial location. Changes in auditory pitch alter the brightness, size, and spatial height of synaesthetic experiences in a systematic manner resembling the cross-modal correspondences of non-synaesthetes, implying synaesthesia may recruit cognitive/neural mechanisms for 'normal' cross-modal processes. To objectively assess the impact of synaesthetic objects on behaviour, we devised a multi-feature cross-modal synaesthetic congruency paradigm and asked participants to perform speeded colour or shape discrimination. We found irrelevant sounds influenced performance, as quantified by congruency effects, demonstrating that synaesthetes were not able to suppress their synaesthetic experiences even when these were irrelevant for the task. Furthermore, we found some evidence for task-specific effects consistent with feature-based attention acting on the constituent features of synaesthetic objects: synaesthetic colours appeared to have a stronger impact on performance than synaesthetic shapes when synaesthetes attended to colour, and vice versa when they attended to shape. We provide the first objective evidence that visual synaesthetic experience can involve multiple features forming object-like percepts and suggest that each feature can be selected by attention despite it being internally generated. These findings suggest theories of the brain mechanisms of synaesthesia need to incorporate a broader neural network underpinning multiple visual features, perceptual knowledge, and feature integration, rather than

  19. Early-onset binocularity in preterm infants reveals experience-dependent visual development in humans

    PubMed Central

    Jandó, Gábor; Mikó-Baráth, Eszter; Markó, Katalin; Hollódy, Katalin; Török, Béla; Kovacs, Ilona

    2012-01-01

    Although there is a great deal of knowledge regarding the phylo- and ontogenetic plasticity of the neocortex, the precise nature of environmental impact on the newborn human brain is still one of the most controversial issues of neuroscience. The leading model–system of experience-dependent brain development is binocular vision, also called stereopsis. Here, we show that extra postnatal visual experience in preterm human neonates leads to a change in the developmental timing of binocular vision. The onset age of binocular function, as measured by the visual evoked response to dynamic random dot correlograms (DRDC-VEP), appears to be at around the same time after birth in preterm (4.07 mo) and full-term (3.78 mo) infants. To assess the integrity of the visual pathway in the studied infants, we also measured the latency of the visual-evoked response to pattern reversal stimuli (PR-VEP). PR-VEP latency is not affected by premature birth, demonstrating that the maturation of the visual pathway follows a preprogrammed developmental course. Despite the immaturity of the visual pathway, clearly demonstrated by the PR-VEP latencies, our DRCD-VEP data show that the visual cortex is remarkably ready to accept environmental stimulation right after birth. This early plasticity makes full use of the available extra stimulation time in preterm human infants and results in an early onset of cortical binocularity. According to our data, the developmental processes preceding the onset of binocular function are not preprogrammed, and the mechanisms turning on stereopsis are extremely experience-dependent in humans. PMID:22711824

  20. 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. PMID:25413274

  1. Meiotic abnormalities

    SciTech Connect

    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.

  2. Personal experience with narrated events modulates functional connectivity within visual and motor systems during story comprehension.

    PubMed

    Chow, Ho Ming; Mar, Raymond A; Xu, Yisheng; Liu, Siyuan; Wagage, Suraji; Braun, Allen R

    2015-04-01

    Past experience of everyday life activities, which forms the basis of our knowledge about the world, greatly affects how we understand stories. Yet, little is known about how this influence is instantiated in the human brain. Here, we used functional magnetic resonance imaging to investigate how past experience facilitates functional connectivity during the comprehension of stories rich in perceptual and motor details. We found that comprehenders' past experience with the scenes and actions described in the narratives selectively modulated functional connectivity between lower- and higher-level areas within the neural systems for visual and motor processing, respectively. These intramodal interactions may play an important role in integrating personal knowledge about a narrated situation with an evolving discourse representation. This study provides empirical evidence consistent with the idea that regions related to visual and motor processing are involved in the reenactment of experience as proposed by theories of embodied cognition. PMID:25545633

  3. 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…

  4. Relative Roles of Experience/Learning and Visual Factors on Radiographic Inspector Performance.

    ERIC Educational Resources Information Center

    Megling, Robert C.; Abrams, Macy L.

    The purpose of this research was to determine the relative roles of experience/learning and selected visual aptitude factors on the ability to detect and identify indications of defects in X-ray film of welds and other materials. Penetrameter Detection and Defect Identification Tests were developed to measure the ability of radiographic film…

  5. 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 used to…

  6. 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…

  7. 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…

  8. The Dynamics of Visual Art Dialogues: Experiences to Be Used in Hospital Settings with Visual Art Enrichment

    PubMed Central

    Wikström, Britt-Maj

    2011-01-01

    Objectives. Given that hospitals have environmental enrichment with paintings and visual art arrangement, it would be meaningful to develop and document how hospital art could be used by health professionals. Methods. The study was undertaken at an art site in Sweden. During 1-hour sessions, participants (n = 20) get together in an art gallery every second week five times. Results. According to the participants a new value was perceived. From qualitative analyses, three themes appear: raise association, mentally present, and door-opener. In addition 72% of the participants reported makes me happy and gives energy and inspiration, and 52% reported that dialogues increase inspiration, make you involved, and stimulate curiosity. Conclusion. The present study supported the view that visual art dialogue could be used by health care professionals in a structured manner and that meaningful art stimulation, related to a person's experiences, could be of importance for the patients. Implementing art dialogues in hospital settings could be a fruitful working tool for nurses, a complementary manner of patient communication. PMID:22242200

  9. Effects of Fluoxetine and Visual Experience on Glutamatergic and GABAergic Synaptic Proteins in Adult Rat Visual Cortex.

    PubMed

    Beshara, Simon; Beston, Brett R; Pinto, Joshua G A; Murphy, Kathryn M

    2015-01-01

    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

  10. Subjective time dilation: spatially local, object-based, or a global visual experience?

    PubMed

    New, Joshua J; Scholl, Brian J

    2009-01-01

    Time can appear to slow down in certain brief real-life events-e.g. during car accidents or critical moments of athletes' performances. Such time dilation can also be produced to a smaller degree in the laboratory by 'oddballs' presented in series of otherwise identical stimuli. We explored the spatial distribution of subjective time dilation: Does time expand only for the oddball objects themselves, only for the local spatial region including the oddball, or for the entire visual field? Because real-life traumatic events provoke an apparently global visual experience of time expansion, we predicted-and observed-that a locally discrete oddball would also dilate the apparent duration of other concurrent events in other parts of the visual field. This 'dilation at a distance' was not diminished by increasing spatial separation between the oddball and target events, and was not influenced by manipulations of objecthood that drive object-based attention. In addition, behaviorally 'urgent' oddballs (looming objects) yielded time dilation, but visually similar receding objects did not. We interpret these results in terms of the influence of attention on time perception-where attention reflects general arousal and faster internal pacing rather than spatial or object-based selection, per se. As a result, attention influences subjective time dilation as a global visual experience. PMID:19271914

  11. Functional binocular vision is not dependent on visual experience in the praying mantis.

    PubMed

    Mathis, U; Eschbach, S; Rossel, S

    1992-08-01

    In vertebrates, it has been shown that binocular visual experience is necessary to develop normal spatial vision. We have investigated whether this is also true for an invertebrate, the praying mantis. The praying mantis is a predatory insect in which prey localization involves the use of binocular disparities. We raised mantids which had one eye occluded throughout development and tested monocular visual fixation and binocular distance estimation in the adult animals. The results revealed that both fixation and prey catching behavior were normally functional in the monocularly reared animals. Thus we conclude that, in mantids, binocular vision is based on a fixed mode of development. PMID:1504028

  12. Dual-monitor deterministic hardware for visual stimuli generation in neuroscience experiments.

    PubMed

    Gazziro, Mario; Almeida, Lirio

    2010-01-01

    This article describes the development of a dual-monitor visual stimulus generator that is used in neuroscience experiments with invertebrates such as flies. The experiment consists in the visualization of two fixed images that are displaced horizontally according to the stimulus data. The system was developed using off-the-shelf FPGA kits and it is capable of displaying 640x480 pixels with 256 intensity levels at 200 frames per second (FPS) on each monitor. A Raster plot of the experiment with the superimposed stimuli was generated as the result of this work. A novel architecture was developed, using the same DOT Clock for both monitors, and its implementation generates a perfect synchronism in both devices. PMID:21096378

  13. Congenital Abnormalities

    MedlinePlus

    ... serious health problems (e.g. Down syndrome ). Single-Gene Abnormalities Sometimes the chromosomes are normal in number, ... blood flow to the fetus impair fetal growth. Alcohol consumption and certain drugs during pregnancy significantly increase ...

  14. Craniofacial Abnormalities

    MedlinePlus

    ... of the skull and face. Craniofacial abnormalities are birth defects of the face or head. Some, like cleft ... palate, are among the most common of all birth defects. Others are very rare. Most of them affect ...

  15. Walking abnormalities

    MedlinePlus

    ... include: Arthritis of the leg or foot joints Conversion disorder (a psychological disorder) Foot problems (such as a ... injuries. For an abnormal gait that occurs with conversion disorder, counseling and support from family members are strongly ...

  16. Chromosome Abnormalities

    MedlinePlus

    ... decade, newer techniques have been developed that allow scientists and doctors to screen for chromosomal abnormalities without using a microscope. These newer methods compare the patient's DNA to a normal DNA ...

  17. Nail abnormalities

    MedlinePlus

    Nail abnormalities are problems with the color, shape, texture, or thickness of the fingernails or toenails. ... Fungus or yeast cause changes in the color, texture, and shape of the nails. Bacterial infection may ...

  18. Segmentation of dance movement: effects of expertise, visual familiarity, motor experience and music

    PubMed Central

    Bläsing, Bettina E.

    2015-01-01

    According to event segmentation theory, action perception depends on sensory cues and prior knowledge, and the segmentation of observed actions is crucial for understanding and memorizing these actions. While most activities in everyday life are characterized by external goals and interaction with objects or persons, this does not necessarily apply to dance-like actions. We investigated to what extent visual familiarity of the observed movement and accompanying music influence the segmentation of a dance phrase in dancers of different skill level and non-dancers. In Experiment 1, dancers and non-dancers repeatedly watched a video clip showing a dancer performing a choreographed dance phrase and indicated segment boundaries by key press. Dancers generally defined less segment boundaries than non-dancers, specifically in the first trials in which visual familiarity with the phrase was low. Music increased the number of segment boundaries in the non-dancers and decreased it in the dancers. The results suggest that dance expertise reduces the number of perceived segment boundaries in an observed dance phrase, and that the ways visual familiarity and music affect movement segmentation are modulated by dance expertise. In a second experiment, motor experience was added as factor, based on empirical evidence suggesting that action perception is modified by visual and motor expertise in different ways. In Experiment 2, the same task as in Experiment 1 was performed by dance amateurs, and was repeated by the same participants after they had learned to dance the presented dance phrase. Less segment boundaries were defined in the middle trials after participants had learned to dance the phrase, and music reduced the number of segment boundaries before learning. The results suggest that specific motor experience of the observed movement influences its perception and anticipation and makes segmentation broader, but not to the same degree as dance expertise on a professional

  19. 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…

  20. 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,…

  1. 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. PMID:25834984

  2. A desert ant's memory of recent visual experience and the control of route guidance

    PubMed Central

    Collett, Matthew

    2014-01-01

    Insects such as desert ants learn stereotyped visual routes between their nests and reliable food sites. Studies here reveal an important control element for ensuring that the route memories are used appropriately. They find that visual route memories can be disengaged, so that they do not provide guidance, even when all appropriate visual cues are present and when there are no competing guidance cues. Ants were trained along a simple route dominated by a single isolated landmark. If returning ants were caught just before entering the nest and replaced at the feeder, then they often interrupted the recapitulation of their homeward route with a period of apparent confusion during which the route memories were ignored. A series of experiments showed that this confusion occurred in response to the repetition of the route, and that the ants must therefore maintain some kind of a memory of their visual experience on the current trip home. A conceptual model of route guidance is offered to explain the results here. It proposes how the memory might act and suggests a general role for disengagement in regulating route guidance. PMID:24870046

  3. Hypersonic Nozzle/Afterbody Experiment: Flow Visualization and Boundary Layer Experiments

    NASA Technical Reports Server (NTRS)

    Keener, Earl R.; Spaid, Frank W.; Arnold, James O. (Technical Monitor)

    1994-01-01

    This study was conducted to experimentally characterize the flow field created by the interaction of a single-expansion-ramp-nozzle (SERN) flow with a hypersonic external stream Data were obtained from a generic nozzle/afterbody model in the 3.5-Foot Hypersonic Wind Tunnel of the NASA Ames Research Center in a cooperative experimental program involving Ames and the McDonnell Douglas Aerospace. The model design and test planning were performed in close cooperation with members of the Ames computational fluid dynamics (CFD) team for the National Aero-Space Plane (NASP) program. This paper presents experimental results consisting of oil-flow and shadowgraph flow-visualization photographs, afterbody surface-pressure distributions, boundary-layer rake measurements, and Preston-tube skin-friction measurements.

  4. 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. PMID:26582987

  5. Aesthetic perception of visual textures: a holistic exploration using texture analysis, psychological experiment, and perception modeling

    PubMed Central

    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. PMID:26582987

  6. 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. PMID:26488641

  7. EXPERIENCE-DEPENDENT REGULATION OF TRKB ISOFORMS IN RODENT VISUAL CORTEX

    PubMed Central

    Bracken, Bethany K.; Turrigiano, Gina G.

    2010-01-01

    Within primary visual cortex (V1), BDNF signaling through its high affinity receptor TrkB is important for normal development and experience-dependent plasticity. TrkB is expressed in several alternatively spliced isoforms, including full length TrkB (TrkB.FL), and several truncated isoforms (TrkB.T1, TrkB.T2 and TrkB.T4) that lack the intracellular tyrosine kinase domain. These isoforms are important components of BDNF signaling, yet little is known about the developmental or experience-dependent regulation of their expression. Using immunohistochemistry, we found TrkB.FL and TrkB.T1 expressed in interneurons and pyramidal neurons within V1, but not in cortical astrocytes. We used real-time PCR to quantify changes in mRNA expression of BDNF, the four TrkB isoforms, and the low affinity receptor P75NTR during normal development, and in response to visual deprivation at two different ages. BDNF expression increased between postnatal days 10 (P10) and P30, and was rapidly down-regulated by 3 days of visual deprivation during both the pre-critical period (P14–P17) and the critical period (P18–P21). Over the same developmental period expression of each TrkB isoform was regulated independently; TrkB.T1 increased, TrkB.FL and TrkB.T2 decreased, and TrkB.T4 showed transient changes. Neither brief visual deprivation nor prolonged dark-rearing induced changes in TrkB.FL or TrkB.T1 expression. However, TrkB.T4 expression was reduced by brief visual deprivation, while TrkB.T4, TrkB.T2 and P75NTR were up-regulated by prolonged dark-rearing into the critical period. Our data indicate that TrkB isoform expression can be selectively regulated by visual experience, and may contribute to experience-dependent cortical plasticity. PMID:19224567

  8. Auditory-visual aversive stimuli modulate the conscious experience of fear.

    PubMed

    Taffou, Marine; Guerchouche, Rachid; Drettakis, George; Viaud-Delmon, Isabelle

    2013-01-01

    In a natural environment, affective information is perceived via multiple senses, mostly audition and vision. However, the impact of multisensory information on affect remains relatively undiscovered. In this study, we investigated whether the auditory-visual presentation of aversive stimuli influences the experience of fear. We used the advantages of virtual reality to manipulate multisensory presentation and to display potentially fearful dog stimuli embedded in a natural context. We manipulated the affective reactions evoked by the dog stimuli by recruiting two groups of participants: dog-fearful and non-fearful participants. The sensitivity to dog fear was assessed psychometrically by a questionnaire and also at behavioral and subjective levels using a Behavioral Avoidance Test (BAT). Participants navigated in virtual environments, in which they encountered virtual dog stimuli presented through the auditory channel, the visual channel or both. They were asked to report their fear using Subjective Units of Distress. We compared the fear for unimodal (visual or auditory) and bimodal (auditory-visual) dog stimuli. Dog-fearful participants as well as non-fearful participants reported more fear in response to bimodal audiovisual compared to unimodal presentation of dog stimuli. These results suggest that fear is more intense when the affective information is processed via multiple sensory pathways, which might be due to a cross-modal potentiation. Our findings have implications for the field of virtual reality-based therapy of phobias. Therapies could be refined and improved by implicating and manipulating the multisensory presentation of the feared situations. PMID:24319928

  9. 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. PMID:26853050

  10. Coexpression of two visual pigments in a photoreceptor causes an abnormally broad spectral sensitivity in the eye of the butterfly Papilio xuthus.

    PubMed

    Arikawa, Kentaro; Mizuno, Shin; Kinoshita, Michiyo; Stavenga, Doekele G

    2003-06-01

    The compound eye of the butterfly Papilio xuthus consists of three different types of ommatidia, each containing nine photoreceptor cells (R1-R9). We have found previously that the R5-R8 photoreceptors of type II ommatidia coexpress two different mRNAs, encoding opsins of green- and orange-red-absorbing visual pigments (Kitamoto et al., 1998). Do these cells contain two functionally distinct visual pigments? First, we identified the sensitivity spectrum of these photoreceptors by using combined intracellular recording and dye injection. We thus found that the R5-R8 of type II ommatidia have a characteristic sensitivity spectrum extending over an excessively broad spectral range, from the violet to the red region; the photoreceptors are therefore termed broadband photoreceptors. The spectral shape was interpreted with a computational model for type II ommatidia, containing a UV visual pigment in cells R1 and R2, two green visual pigments in cells R3 and R4, a far-UV-absorbing screening pigment (3-hydroxyretinol) in the distal part of the ommatidium, and a red-screening pigment that surrounds the rhabdom. The modeling suggests that both visual pigments in the R5-R8 photoreceptors participate in phototransduction. This work provides the first compelling evidence that multiple visual pigments participate in phototransduction in single invertebrate photoreceptors. PMID:12805293

  11. 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

  12. 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

  13. The effects of age and experience on memory for visually presented music.

    PubMed

    Meinz, E J; Salthouse, T A

    1998-01-01

    Increased age is often associated with lower levels of performance in tests of memory for spatial information. The primary question in the current study was whether this relationship could be moderated as a function of one's relevant experience and/or knowledge. Stimulus materials consisted of short (7-11 note), visually presented musical melodies and structurally equivalent nonmusical stimuli. Participants (N = 128) were recruited from a wide range of age and experience levels. Although there were strong main effects of age and experience on memory for music, there was no evidence that the age-related differences in memory for these stimuli were smaller for individuals with moderate to large amounts of experience with music. PMID:9469173

  14. Bouncing droplets: a classroom experiment to visualize wave-particle duality on the macroscopic level

    NASA Astrophysics Data System (ADS)

    Sleutel, Pascal; Dietrich, Erik; Van der Veen, Jan T.; van Joolingen, Wouter R.

    2016-09-01

    This study brings a recently discovered macroscopic phenomenon with wave-particle characteristics into the classroom. The system consists of a liquid droplet levitating over a vertically shaken liquid pool. The droplets allow visualization of a wave–particle system in a directly observable way. We show how to interpret this macroscopic phenomenon and how to set up and carry out this experiment. A class of students performed single slit diffraction experiments with droplets. By scoring individual droplet trajectories students find a diffraction pattern. This pilot application in the classroom shows that students can study and discuss the wave–particle nature of the bouncing droplet experiment. The experiment therefore provides a useful opportunity to show wave–particle behavior on the macroscopic level.

  15. Association of interatrial septal abnormalities with cardiac impulse conduction disorders in adult patients: experience from a tertiary center in Kosovo

    PubMed Central

    Bakalli, Aurora; Pllana, Ejup; Koçinaj, Dardan; Bekteshi, Tefik; Dragusha, Gani; Gashi, Masar; Musliu, Nebih; Gashi, Zaim

    2011-01-01

    Interatrial septal disorders, which include: atrial septal defect, patent foramen ovale and atrial septal aneurysm, are frequent congenital anomalies found in adult patients. Early detection of these anomalies is important to prevent their hemodynamic and/or thromboembolic consequences. The aims of this study were: to assess the association between impulse conduction disorders and anomalies of interatrial septum; to determine the prevalence of different types of interatrial septum abnormalities; to assess anatomic, hemodynamic, and clinical consequences of interatrial septal pathologies. Fifty-three adult patients with impulse conduction disorders and patients without ECG changes but with signs of interatrial septal abnormalities, who were referred to our center for echocardiography, were included in a prospective transesophageal echocardiography study. Interatrial septal anomalies were detected in around 85% of the examined patients. Patent foramen ovale was encountered in 32% of the patients, and in combination with atrial septal aneurysm in an additional 11.3% of cases. Atrial septal aneurysm and atrial septal defect were diagnosed with equal frequency in 20.7% of our study population. Impulse conduction disorders were significantly more suggestive of interatrial septal anomalies than clinical signs and symptoms observed in our patients (84.91% vs 30.19%, P=0.002). Right bundle branch block was the most frequent impulse conduction disorder, found in 41 (77.36%) cases. We conclude that interatrial septal anomalies are highly associated with impulse conduction disorders, particularly with right bundle branch block. Impulse conduction disorders are more indicative of interatrial septal abnormalities in earlier stages than can be understood from the patient’s clinical condition. PMID:21977304

  16. Association of interatrial septal abnormalities with cardiac impulse conduction disorders in adult patients: experience from a tertiary center in Kosovo.

    PubMed

    Bakalli, Aurora; Pllana, Ejup; Koçinaj, Dardan; Bekteshi, Tefik; Dragusha, Gani; Gashi, Masar; Musliu, Nebih; Gashi, Zaim

    2011-01-01

    INTERATRIAL SEPTAL DISORDERS, WHICH INCLUDE: atrial septal defect, patent foramen ovale and atrial septal aneurysm, are frequent congenital anomalies found in adult patients. Early detection of these anomalies is important to prevent their hemodynamic and/or thromboembolic consequences. The aims of this study were: to assess the association between impulse conduction disorders and anomalies of interatrial septum; to determine the prevalence of different types of interatrial septum abnormalities; to assess anatomic, hemodynamic, and clinical consequences of interatrial septal pathologies. Fifty-three adult patients with impulse conduction disorders and patients without ECG changes but with signs of interatrial septal abnormalities, who were referred to our center for echocardiography, were included in a prospective transesophageal echocardiography study. Interatrial septal anomalies were detected in around 85% of the examined patients. Patent foramen ovale was encountered in 32% of the patients, and in combination with atrial septal aneurysm in an additional 11.3% of cases. Atrial septal aneurysm and atrial septal defect were diagnosed with equal frequency in 20.7% of our study population. Impulse conduction disorders were significantly more suggestive of interatrial septal anomalies than clinical signs and symptoms observed in our patients (84.91% vs 30.19%, P=0.002). Right bundle branch block was the most frequent impulse conduction disorder, found in 41 (77.36%) cases. We conclude that interatrial septal anomalies are highly associated with impulse conduction disorders, particularly with right bundle branch block. Impulse conduction disorders are more indicative of interatrial septal abnormalities in earlier stages than can be understood from the patient's clinical condition. PMID:21977304

  17. Experience-Dependent and Independent Binocular Correspondence of Receptive Field Subregions in Mouse Visual Cortex

    PubMed Central

    Sarnaik, Rashmi; Wang, Bor-Shuen; Cang, Jianhua

    2014-01-01

    The convergence of eye-specific thalamic inputs to visual cortical neurons forms the basis of binocular vision. Inputs from the same eye that signal light increment (On) and decrement (Off) are spatially segregated into subregions, giving rise to cortical receptive fields (RFs) that are selective for stimulus orientation. Here we map RFs of binocular neurons in the mouse primary visual cortex using spike-triggered average. We find that subregions of the same sign (On–On and Off–Off) preferentially overlap between the 2 monocular RFs, leading to binocularly matched orientation tuning. We further demonstrate that such subregion correspondence and the consequent matching of RF orientation are disrupted in mice reared in darkness during development. Surprisingly, despite the lack of all postnatal visual experience, a substantial degree of subregion correspondence still remains. In addition, dark-reared mice show normal monocular RF structures and binocular overlap. These results thus reveal the specific roles of experience-dependent and -independent processes in binocular convergence and refinement of On and Off inputs onto single cortical neurons. PMID:23389996

  18. Combining Real World Experiences with WorldWide Telescope Visualization to Build a Better Parallax Lab

    NASA Astrophysics Data System (ADS)

    Ladd, E. F.; Gingrich, E. C.; Nottis, K. E. K.; Udomprasert, P.; Goodman, A. A.

    2015-11-01

    We present a lab activity designed to help students understand the concept of parallax in both astronomical and non-astronomical contexts. In an outdoor setting, students learn the methodology of distance determination via parallax. They identify a distant landmark to establish a reference of direction, and then measure the change in apparent direction for more nearby objects as they change position in a 2 meter radius “orbit” around the “Sun.” This hands-on activity involves large, visually-discernable angles so that students can internalize the concept of parallax from everyday experience. However, students often have difficulty transferring this experience to the astronomical realm, so we pair this hands-on activity with a more explicitly astronomically-based activity using the WorldWide Telescope visualization environment. Students apply the same methodology in this environment and learn how the apparent motion of stars is related to their distance from Earth. The combination of hands-on activity and computer-aided visualization is designed to produce a deeper understanding of parallax in the astronomical environment, and an improved understanding of the inherently three-dimensional distribution of objects in our universe. More formal assessment is underway.

  19. 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. PMID:25935047

  20. Sensory experience shapes the development of the visual system's first synapse.

    PubMed

    Dunn, Felice A; Della Santina, Luca; Parker, Edward D; Wong, Rachel O L

    2013-12-01

    Specific connectivity patterns among neurons create the basic architecture underlying parallel processing in our nervous system. Here we focus on the visual system's first synapse to examine the structural and functional consequences of sensory deprivation on the establishment of parallel circuits. Dark rearing reduces synaptic strength between cones and cone bipolar cells, a previously unappreciated effect of sensory deprivation. In contrast, rod bipolar cells, which utilize the same glutamate receptor to contact rods, are unaffected by dark rearing. Underlying the physiological changes, we find the localization of metabotropic glutamate receptors within cone bipolar, but not rod bipolar, cell dendrites is a light-dependent process. Furthermore, although cone bipolar cells share common cone partners, each bipolar cell type that we examined depends differentially on sensory input to achieve mature connectivity. Thus, visual experience differentially affects maturation of rod versus cone pathways and of cell types within the cone pathway. PMID:24314727

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

    SciTech Connect

    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 at 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.

  2. Miscible and immiscible experiments on the Rayleigh-Taylor instability using planar laser induced fluorescence visualization

    NASA Astrophysics Data System (ADS)

    Mokler, Matthew; Roberts, Michael; Jacobs, Jeffrey

    2013-11-01

    Incompressible Rayleigh-Taylor instability experiments are presented in which two stratified liquids having Atwood number of 0.2 are accelerated in a vertical linear induction motor driven drop tower. A test sled having only vertical freedom of motion contains the experiment tank and visualization equipment. The sled is positioned at the top of the tower within the linear induction motors and accelerated downward causing the initially stable interface to be unstable and allowing the Rayleigh-Taylor instability to develop. Forced and unforced experiments are conducted using both immiscible and miscible liquid combinations. Forced initial perturbations are produced by vertically oscillating the test sled prior to the start of acceleration. The interface is visualized using a 445 nm laser light source that illuminates a fluorescent dye mixed in one of the fluids. The resulting fluorescent images are recorded using a monochromatic high speed video camera. The laser beam is synchronously swept across the fluorescent fluid, at the frame rate of the camera, exposing a single plane of the interface allowing for the measurement of spike and bubble growth. Comparisons between miscible and immiscible mixing layer distributions are made from the resulting interface concentration profiles.

  3. Visualization experiments of biodegradation in porous media and calculation of the biodegradation rate

    NASA Astrophysics Data System (ADS)

    Vayenas, D. V.; Michalopoulou, E.; Constantinides, G. N.; Pavlou, S.; Payatakes, A. C.

    Biodegradation in porous media is studied with carefully controlled and well-characterized experiments in model porous media constructed of etched glass. Porous media of this type allow visual observation of the phenomena that take place at pore scale. An aqueous solution of five organic pollutants (toluene, phenol, o-cresol, naphthalene and 1,2,3-trimethylbenzene) was used as a model NAPL (representing creosote). The bacteria used were Pseudomonas fluorescens, which are indigenous (even predominant) in many contaminated soils. The maximum aqueous concentrations of the specific organic substances, below which biodegradation becomes possible, were determined as a function of temperature from toxicity experiments. Visualization experiments were made under various flow velocities and organic loadings to study the morphology and thickness of the biofilm as a function of the pore size and the distance from the entrance, and the efficiency of biodegradation. The efficiency of biodegradation decreased as the aqueous concentration of NAPL at the inlet increased and/or as the flow velocity increased. The thickness of biofilm decreased as the distance from the inlet increased and/or the pore diameter decreased. A quasi-steady-state theoretical model of biodegradation was used to calculate the values of the mesoscopic biochemical rates and to predict the profile of NAPL concentration in the porous medium and the thickness of biofilm in pores. The agreement between experimental data and model predictions is quite satisfactory.

  4. Towards a comprehensive model for predicting the quality of individual visual experience

    NASA Astrophysics Data System (ADS)

    Zhu, Yi; Heynderickx, Ingrid; Hanjalic, Alan; Redi, Judith A.

    2015-03-01

    Recently, a lot of effort has been devoted to estimating the Quality of Visual Experience (QoVE) in order to optimize video delivery to the user. For many decades, existing objective metrics mainly focused on estimating the perceived quality of a video, i.e., the extent to which artifacts due to e.g. compression disrupt the appearance of the video. Other aspects of the visual experience, such as enjoyment of the video content, were, however, neglected. In addition, typically Mean Opinion Scores were targeted, deeming the prediction of individual quality preferences too hard of a problem. In this paper, we propose a paradigm shift, and evaluate the opportunity of predicting individual QoVE preferences, in terms of video enjoyment as well as perceived quality. To do so, we explore the potential of features of different nature to be predictive for a user's specific experience with a video. We consider thus not only features related to the perceptual characteristics of a video, but also to its affective content. Furthermore, we also integrate in our framework the information about the user and use context. The results show that effective feature combinations can be identified to estimate the QoVE from the perspective of both the enjoyment and perceived quality.

  5. Visual Experience Determines the Use of External Reference Frames in Joint Action Control

    PubMed Central

    Dolk, Thomas; Liepelt, Roman; Prinz, Wolfgang; Fiehler, Katja

    2013-01-01

    Vision plays a crucial role in human interaction by facilitating the coordination of one's own actions with those of others in space and time. While previous findings have demonstrated that vision determines the default use of reference frames, little is known about the role of visual experience in coding action-space during joint action. Here, we tested if and how visual experience influences the use of reference frames in joint action control. Dyads of congenitally-blind, blindfolded-sighted, and seeing individuals took part in an auditory version of the social Simon task, which required each participant to respond to one of two sounds presented to the left or right of both participants. To disentangle the contribution of external—agent-based and response-based—reference frames during joint action, participants performed the task with their respective response (right) hands uncrossed or crossed over one another. Although the location of the auditory stimulus was completely task-irrelevant, participants responded overall faster when the stimulus location spatially corresponded to the required response side than when they were spatially non-corresponding: a phenomenon known as the social Simon effect (SSE). In sighted participants, the SSE occurred irrespective of whether hands were crossed or uncrossed, suggesting the use of external, response-based reference frames. Congenitally-blind participants also showed an SSE, but only with uncrossed hands. We argue that congenitally-blind people use both agent-based and response-based reference frames resulting in conflicting spatial information when hands are crossed and, thus, canceling out the SSE. These results imply that joint action control functions on the basis of external reference frames independent of the presence or (transient/permanent) absence of vision. However, the type of external reference frames used for organizing motor control in joint action seems to be determined by visual experience. PMID

  6. Gene Expression Browser: large-scale and cross-experiment microarray data integration, management, search & visualization

    PubMed Central

    2010-01-01

    Background In the last decade, a large amount of microarray gene expression data has been accumulated in public repositories. Integrating and analyzing high-throughput gene expression data have become key activities for exploring gene functions, gene networks and biological pathways. Effectively utilizing these invaluable microarray data remains challenging due to a lack of powerful tools to integrate large-scale gene-expression information across diverse experiments and to search and visualize a large number of gene-expression data points. Results Gene Expression Browser is a microarray data integration, management and processing system with web-based search and visualization functions. An innovative method has been developed to define a treatment over a control for every microarray experiment to standardize and make microarray data from different experiments homogeneous. In the browser, data are pre-processed offline and the resulting data points are visualized online with a 2-layer dynamic web display. Users can view all treatments over control that affect the expression of a selected gene via Gene View, and view all genes that change in a selected treatment over control via treatment over control View. Users can also check the changes of expression profiles of a set of either the treatments over control or genes via Slide View. In addition, the relationships between genes and treatments over control are computed according to gene expression ratio and are shown as co-responsive genes and co-regulation treatments over control. Conclusion Gene Expression Browser is composed of a set of software tools, including a data extraction tool, a microarray data-management system, a data-annotation tool, a microarray data-processing pipeline, and a data search & visualization tool. The browser is deployed as a free public web service (http://www.ExpressionBrowser.com) that integrates 301 ATH1 gene microarray experiments from public data repositories (viz. the Gene

  7. Visualizing the Impact of Art: An Update and Comparison of Current Psychological Models of Art Experience.

    PubMed

    Pelowski, Matthew; Markey, Patrick S; Lauring, Jon O; Leder, Helmut

    2016-01-01

    The last decade has witnessed a renaissance of empirical and psychological approaches to art study, especially regarding cognitive models of art processing experience. This new emphasis on modeling has often become the basis for our theoretical understanding of human interaction with art. Models also often define areas of focus and hypotheses for new empirical research, and are increasingly important for connecting psychological theory to discussions of the brain. However, models are often made by different researchers, with quite different emphases or visual styles. Inputs and psychological outcomes may be differently considered, or can be under-reported with regards to key functional components. Thus, we may lose the major theoretical improvements and ability for comparison that can be had with models. To begin addressing this, this paper presents a theoretical assessment, comparison, and new articulation of a selection of key contemporary cognitive or information-processing-based approaches detailing the mechanisms underlying the viewing of art. We review six major models in contemporary psychological aesthetics. We in turn present redesigns of these models using a unified visual form, in some cases making additions or creating new models where none had previously existed. We also frame these approaches in respect to their targeted outputs (e.g., emotion, appraisal, physiological reaction) and their strengths within a more general framework of early, intermediate, and later processing stages. This is used as a basis for general comparison and discussion of implications and future directions for modeling, and for theoretically understanding our engagement with visual art. PMID:27199697

  8. Visualizing the Impact of Art: An Update and Comparison of Current Psychological Models of Art Experience

    PubMed Central

    Pelowski, Matthew; Markey, Patrick S.; Lauring, Jon O.; Leder, Helmut

    2016-01-01

    The last decade has witnessed a renaissance of empirical and psychological approaches to art study, especially regarding cognitive models of art processing experience. This new emphasis on modeling has often become the basis for our theoretical understanding of human interaction with art. Models also often define areas of focus and hypotheses for new empirical research, and are increasingly important for connecting psychological theory to discussions of the brain. However, models are often made by different researchers, with quite different emphases or visual styles. Inputs and psychological outcomes may be differently considered, or can be under-reported with regards to key functional components. Thus, we may lose the major theoretical improvements and ability for comparison that can be had with models. To begin addressing this, this paper presents a theoretical assessment, comparison, and new articulation of a selection of key contemporary cognitive or information-processing-based approaches detailing the mechanisms underlying the viewing of art. We review six major models in contemporary psychological aesthetics. We in turn present redesigns of these models using a unified visual form, in some cases making additions or creating new models where none had previously existed. We also frame these approaches in respect to their targeted outputs (e.g., emotion, appraisal, physiological reaction) and their strengths within a more general framework of early, intermediate, and later processing stages. This is used as a basis for general comparison and discussion of implications and future directions for modeling, and for theoretically understanding our engagement with visual art. PMID:27199697

  9. Inversion of the anatomical lateralization of chick thalamofugal visual pathway by light experience.

    PubMed

    Koshiba, Mamiko; Kikuchi, Tateki; Yohda, Masafumi; Nakamura, Shun

    2002-02-01

    It has been reported that light exposure to one eye induces functional lateralization, which can be inverted by exposing the opposite eye to the light. However, the anatomical basis of the functional inversion by the light has not been shown. To address this issue, we labeled cells in the dorsolateral anterior thalamus (DLA) using retrograde fluorescent tracers injected into visual Wulst, counted the labeled cell number, and compared the anatomical asymmetry of DLA between the left eye occluded and the right eye occluded chickens. We found that a rostral part of DLA (DLAda) and a lateral/ventral part of DLA differentially projected to the visual cortex ipsilaterally and contralaterally, respectively. These regions showed anatomical asymmetry that was inverted by the light. An antibody against a nicotinic acetylcholine receptor subunit more intensively and widely stained the side of DLA receiving the light stimulation and the cell labeled by the tracers co-localized with the immunoreactive neuropil. These results indicated that the light experience induced the anatomical lateralization of thalamofugal visual pathway. PMID:11803112

  10. Enhanced prenatal auditory experience facilitates species-specific visual responsiveness in bobwhite quail chicks (Colinus virginianus).

    PubMed

    Lickliter, R; Stoumbos, J

    1991-03-01

    Premature stimulation of a later developing sensory system is known to impact the functioning of earlier developing sensory systems. For example, exposure to premature (prenatal) visual experience results in a decline in species-typical auditory responsiveness in several precocial bird species. The present study examined the influence of experiential enhancement of an earlier developing sensory system on a later developing modality. Specifically, the influence of enhanced prenatal auditory stimulation on subsequent postnatal auditory and visual functioning of bobwhite quail (Colinus virginianus) chicks was assessed. Results indicate that birds receiving exposure to increased amounts of unaltered, species-typical embryonic vocalizations before hatching show species-typical auditory responsiveness at both 12 hr and 24 hr after hatching, but exhibit an accelerated pattern of species-typical visual responsiveness by 24 hr of age. These findings suggest that enhancement of an earlier developing sensory system can facilitate the development of a later developing sensory system and serve to demonstrate the dynamic nature of early perceptual organization. PMID:2032460

  11. Experience of Multisensory Environments in Public Space among People with Visual Impairment.

    PubMed

    Jenkins, Gavin R; Yuen, Hon K; Vogtle, Laura K

    2015-08-01

    This qualitative study explored the role of sensory characteristics embedded in the built environment and whether they support or hinder people with visual impairment in their use of public spaces. An online survey link was e-mailed to the presidents and committee members of each state's chapters and associations of the National Federation of the Blind in the United States, resulting in 451 direct invitations to participate. Written responses of the survey questions from 48 respondents with visual impairment were analyzed. Three main themes: Barriers, Supporters, and Context-Dependence emerged from the respondents' experience of multisensory characteristics within the built environment. The four subthemes subsumed in Barriers were: (1) Population specific design, (2) Extreme sensory backgrounds, (3) Uneven ground surfaces and objects, and (4) Inconsistent lighting. For Supporters, respondents provided specific examples of various sensory characteristics in built environments, including audible cues and echoes, smells, tactile quality of the ground surface, and temperature. Context-Dependence referred to the effects of sensory characteristics embedded in public spaces depending on one's vision condition, the proximity to the sensory cues and the purpose of the activities one was performing at that moment. Findings provide occupational therapy practitioners an in-depth understanding of the transactional relationship between embedded sensory characteristics in the built environment, occupations, and people with visual impairment in order to make appropriate modifications or removal of barriers that affect occupational performance and engagement. Suggestions for occupational therapists as well as architects, designers, planners, policy makers/legislators related to functional sensory cues in the design of built environments were provided to increase accessibility in the use of public spaces by people with visual impairment. PMID:26213952

  12. Experience of Multisensory Environments in Public Space among People with Visual Impairment

    PubMed Central

    Jenkins, Gavin R.; Yuen, Hon K.; Vogtle, Laura K.

    2015-01-01

    This qualitative study explored the role of sensory characteristics embedded in the built environment and whether they support or hinder people with visual impairment in their use of public spaces. An online survey link was e-mailed to the presidents and committee members of each state’s chapters and associations of the National Federation of the Blind in the United States, resulting in 451 direct invitations to participate. Written responses of the survey questions from 48 respondents with visual impairment were analyzed. Three main themes: Barriers, Supporters, and Context-Dependence emerged from the respondents’ experience of multisensory characteristics within the built environment. The four subthemes subsumed in Barriers were: (1) Population specific design, (2) Extreme sensory backgrounds, (3) Uneven ground surfaces and objects, and (4) Inconsistent lighting. For Supporters, respondents provided specific examples of various sensory characteristics in built environments, including audible cues and echoes, smells, tactile quality of the ground surface, and temperature. Context-Dependence referred to the effects of sensory characteristics embedded in public spaces depending on one’s vision condition, the proximity to the sensory cues and the purpose of the activities one was performing at that moment. Findings provide occupational therapy practitioners an in-depth understanding of the transactional relationship between embedded sensory characteristics in the built environment, occupations, and people with visual impairment in order to make appropriate modifications or removal of barriers that affect occupational performance and engagement. Suggestions for occupational therapists as well as architects, designers, planners, policy makers/legislators related to functional sensory cues in the design of built environments were provided to increase accessibility in the use of public spaces by people with visual impairment. PMID:26213952

  13. Lateral spike conduction velocity in the visual cortex affects spatial range of synchronization and receptive field size without visual experience: a learning model with spiking neurons.

    PubMed

    Saam, M; Eckhorn, R

    2000-07-01

    Classical receptive fields (cRF) increase in size from the retina to higher visual centers. The present work shows how temporal properties, in particular lateral spike velocity and spike input correlation, can affect cRF size and position without visual experience. We demonstrate how these properties are related to the spatial range of cortical synchronization if Hebbian learning dominates early development. For this, a largely reduced model of two successive levels of the visual cortex is developed (e.g., areas V1 and V2). It consists of retinotopic networks of spiking neurons with constant spike velocity in lateral connections. Feedforward connections between level 1 and 2 are additive and determine cRF size and shape, while lateral connections within level 1 are modulatory and affect the cortical range of synchronization. Input during development is mimicked by spike trains with spatially homogeneous properties and a confined temporal correlation width. During learning, the homogeneous lateral coupling shrinks to limited coupling structures defining synchronization and related association fields (AF). The size of level-1 synchronization fields determines the lateral coupling range of developing level-1-to-2 connections and, thus, the size of level-2 cRFs, even if the feedforward connections have distance-independent delays. AFs and cRFs increase with spike velocity in the lateral network and temporal correlation width of the input. Our results suggest that AF size of V1 and cRF size of V2 neurons are confined during learning by the temporal width of input correlations and the spike velocity in lateral connections without the need of visual experience. During learning from visual experience, a similar influence of AF size on the cRF size may be operative at successive levels of processing, including other parts of the visual system. PMID:10933233

  14. 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. PMID:24288139

  15. Genome-Wide Screening of Cytogenetic Abnormalities in Multiple Myeloma Patients Using Array-CGH Technique: A Czech Multicenter Experience

    PubMed Central

    Frohlich, Jan; Vallova, Vladimira; Greslikova, Henrieta; Kupska, Renata; Nemec, Pavel; Mikulasova, Aneta; Almasi, Martina; Pour, Ludek; Adam, Zdenek; Sandecka, Viera; Zahradová, Lenka; Hajek, Roman; Kuglik, Petr

    2014-01-01

    Characteristic recurrent copy number aberrations (CNAs) play a key role in multiple myeloma (MM) pathogenesis and have important prognostic significance for MM patients. Array-based comparative genomic hybridization (aCGH) provides a powerful tool for genome-wide classification of CNAs and thus should be implemented into MM routine diagnostics. We demonstrate the possibility of effective utilization of oligonucleotide-based aCGH in 91 MM patients. Chromosomal aberrations associated with effect on the prognosis of MM were initially evaluated by I-FISH and were found in 93.4% (85/91). Incidence of hyperdiploidy was 49.5% (45/91); del(13)(q14) was detected in 57.1% (52/91); gain(1)(q21) occurred in 58.2% (53/91); del(17)(p13) was observed in 15.4% (14/91); and t(4;14)(p16;q32) was found in 18.6% (16/86). Genome-wide screening using Agilent 44K aCGH microarrays revealed copy number alterations in 100% (91/91). Most common deletions were found at 13q (58.9%), 1p (39.6%), and 8p (31.1%), whereas gain of whole 1q was the most often duplicated region (50.6%). Furthermore, frequent homozygous deletions of genes playing important role in myeloma biology such as TRAF3, BIRC1/BIRC2, RB1, or CDKN2C were observed. Taken together, we demonstrated the utilization of aCGH technique in clinical diagnostics as powerful tool for identification of unbalanced genomic abnormalities with prognostic significance for MM patients. PMID:24987674

  16. Uncertainty analysis of thermocouple measurements used in normal and abnormal thermal environment experiments at Sandia's Radiant Heat Facility and Lurance Canyon Burn Site.

    SciTech Connect

    Nakos, James Thomas

    2004-04-01

    It would not be possible to confidently qualify weapon systems performance or validate computer codes without knowing the uncertainty of the experimental data used. This report provides uncertainty estimates associated with thermocouple data for temperature measurements from two of Sandia's large-scale thermal facilities. These two facilities (the Radiant Heat Facility (RHF) and the Lurance Canyon Burn Site (LCBS)) routinely gather data from normal and abnormal thermal environment experiments. They are managed by Fire Science & Technology Department 09132. Uncertainty analyses were performed for several thermocouple (TC) data acquisition systems (DASs) used at the RHF and LCBS. These analyses apply to Type K, chromel-alumel thermocouples of various types: fiberglass sheathed TC wire, mineral-insulated, metal-sheathed (MIMS) TC assemblies, and are easily extended to other TC materials (e.g., copper-constantan). Several DASs were analyzed: (1) A Hewlett-Packard (HP) 3852A system, and (2) several National Instrument (NI) systems. The uncertainty analyses were performed on the entire system from the TC to the DAS output file. Uncertainty sources include TC mounting errors, ANSI standard calibration uncertainty for Type K TC wire, potential errors due to temperature gradients inside connectors, extension wire uncertainty, DAS hardware uncertainties including noise, common mode rejection ratio, digital voltmeter accuracy, mV to temperature conversion, analog to digital conversion, and other possible sources. Typical results for 'normal' environments (e.g., maximum of 300-400 K) showed the total uncertainty to be about {+-}1% of the reading in absolute temperature. In high temperature or high heat flux ('abnormal') thermal environments, total uncertainties range up to {+-}2-3% of the reading (maximum of 1300 K). The higher uncertainties in abnormal thermal environments are caused by increased errors due to the effects of imperfect TC attachment to the test item. 'Best

  17. Experiments on the Fehrer-Raab effect and the 'Weather Station Model' of visual backward masking.

    PubMed

    Neumann, Odmar; Scharlau, Ingrid

    2007-11-01

    The Fehrer-Raab effect (simple reaction time is unaffected by metacontrast masking of the test stimulus) seems to imply that a stimulus can trigger a voluntary reaction without reaching a conscious representation. However, it is also possible that the mask triggers the reaction, and that the masked test stimulus causes a focussing of attention from which processing of the mask profits, thus reaching conscious representation earlier. This is predicted by the Weather Station Model of visual masking. Three experiments tested this explanation. Experiment 1 showed that the masked test stimulus caused a temporal shift of the mask. Experiment 2 showed that the reaction in the Fehrer-Raab effect was not exclusively triggered by a conscious representation of the test stimulus: the mask was involved in evoking the reaction. Experiment 3 again revealed a temporal shift of the mask. However, the shift was only about half as large as the Fehrer-Raab effect. The psychometric functions suggested that the observers used two different cues for their temporal order judgments. The results cast doubts on whether judged temporal order yields a direct estimate of the time of conscious perception. Some methodological alternatives are discussed. PMID:16715303

  18. Psychophysical measures of visual function and everyday perceptual experience in a case of congenital stationary night blindness

    PubMed Central

    Cammack, Jocelyn; Whight, John; Cross, Vinette; Rider, Andrew T; Webster, Andrew R; Stockman, Andrew

    2016-01-01

    An appreciation of the relation between laboratory measures of visual deficit and everyday perceptual experience is fundamental to understanding the impact of a visual condition on patients and so to a fuller characterization of the disorder. This study aims to understand better the interpretative processes by which modified sensory information is perceived by a patient with congenital stationary night blindness and the adaptive strategies that are devised to deal with their measurable visual loss. Psychophysical measurements of temporal resolution, spectral sensitivity, and color discrimination were conducted on a 78-year-old male patient with the condition, who was also interviewed at length about the ways in which his diagnosis affected his daily life. Narrative analysis was employed to identify the relation between his subjective perceptual experiences and functional deficits in identifiable components of the visual system. Psychophysical measurements indicated a complete lack of rod perception and substantially reduced cone sensitivity. Two particular effects of this visual loss emerged during interviews: 1) the development of navigational techniques that relied on light reflections and point sources of light and 2) a reluctance to disclose the extent of visual loss and resulting lifelong psychosocial consequences. This study demonstrates the valuable complementary role that rich descriptive patient testimony can play, in conjunction with laboratory and clinical measurements, in more fully characterizing a disorder and in reaching a more complete understanding of the experience of vision loss. It also evidences the particular suitability of filmmaking techniques as a means of accessing and communicating subjective patient experience. PMID:27601873

  19. Psychophysical measures of visual function and everyday perceptual experience in a case of congenital stationary night blindness.

    PubMed

    Cammack, Jocelyn; Whight, John; Cross, Vinette; Rider, Andrew T; Webster, Andrew R; Stockman, Andrew

    2016-01-01

    An appreciation of the relation between laboratory measures of visual deficit and everyday perceptual experience is fundamental to understanding the impact of a visual condition on patients and so to a fuller characterization of the disorder. This study aims to understand better the interpretative processes by which modified sensory information is perceived by a patient with congenital stationary night blindness and the adaptive strategies that are devised to deal with their measurable visual loss. Psychophysical measurements of temporal resolution, spectral sensitivity, and color discrimination were conducted on a 78-year-old male patient with the condition, who was also interviewed at length about the ways in which his diagnosis affected his daily life. Narrative analysis was employed to identify the relation between his subjective perceptual experiences and functional deficits in identifiable components of the visual system. Psychophysical measurements indicated a complete lack of rod perception and substantially reduced cone sensitivity. Two particular effects of this visual loss emerged during interviews: 1) the development of navigational techniques that relied on light reflections and point sources of light and 2) a reluctance to disclose the extent of visual loss and resulting lifelong psychosocial consequences. This study demonstrates the valuable complementary role that rich descriptive patient testimony can play, in conjunction with laboratory and clinical measurements, in more fully characterizing a disorder and in reaching a more complete understanding of the experience of vision loss. It also evidences the particular suitability of filmmaking techniques as a means of accessing and communicating subjective patient experience. PMID:27601873

  20. Visualizing characteristics of ocean data collected during the Shuttle Imaging Radar-B experiment

    NASA Technical Reports Server (NTRS)

    Tilley, David G.

    1991-01-01

    Topographic measurements of sea surface elevation collected by the Surface Contour Radar (SCR) during NASA's Shuttle Imaging Radar (SIR-B) experiment are plotted as three dimensional surface plots to observe wave height variance along the track of a P-3 aircraft. Ocean wave spectra were computed from rotating altimeter measurements acquired by the Radar Ocean Wave Spectrometer (ROWS). Fourier power spectra computed from SIR-B synthetic aperture radar (SAR) images of the ocean are compared to ROWS surface wave spectra. Fourier inversion of SAR spectra, after subtraction of spectral noise and modeling of wave height modulation, yields topography similar to direct measurements made by SCR. Visual perspectives on the SCR and SAR ocean data are compared. Threshold distinctions between surface elevation and texture modulations of SAR data are considered within the context of a dynamic statistical model of rough surface scattering. The result of these endeavors is insight as to the physical mechanism governing the imaging of ocean waves with SAR.

  1. 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. PMID:24273140

  2. Genome image programs: visualization and interpretation of Escherichia coli microarray experiments.

    PubMed Central

    Zimmer, Daniel P; Paliy, Oleg; Thomas, Brian; Gyaneshwar, Prasad; Kustu, Sydney

    2004-01-01

    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. PMID:15342544

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

    PubMed

    Zold, Camila L; Hussain Shuler, Marshall G

    2015-07-01

    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

  4. 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

  5. LCD Monitors as an Alternative for Precision Demanding Visual Psychophysical Experiments.

    PubMed

    Bognár, Anna; Csibri, Péter; András, Csaba Márk; Sáry, Gyula

    2016-09-01

    Precise timing and presentation of stimuli is critical in vision research, still, the limiting factor in successful recognition is often the monitor itself that is used to present the stimuli. The most widespread method is the use of monitors controlled by personal computers. Traditionally, most experiments used cathode-ray tubes but they are more and more difficult to access, and instead, liquid-crystal displays are getting more and more popular. The two types have fundamentally different working principles and limitations in displaying the stimulus.In our experiments, the temporal precision of the stimulus presentation was in focus. We investigated whether liquid-crystal displays, which are not considered to be fit to display fast successive stimuli, can represent an alternative choice for cathode-ray tubes. We used the double flash and the flicker illusion to compare the technical capabilities of the two monitor types. These illusions not only do require a precise timing but also a very short exposure to the stimuli. At the same time, the interstimulus interval is also of extreme importance. In addition, these illusions require peripheral stimulation of the retina, which is more sensitive to the temporal aspects of the visual stimulus. On the basis of previous studies and our own psychophysical results, we suggest that liquid-crystal displays might be a good alternative for precise, frame-to-frame stimulus presentation even if parts of the stimuli are projected on the peripheral retina. PMID:27271338

  6. Visualization experiment to investigate capillary barrier performance in the context of a Yucca Mountain emplacement drift.

    PubMed

    Tidwell, Vincent C; Glass, Robert J; Chocas, Connie; Barker, Glenn; Orear, Lee

    2003-01-01

    The use of capillary barriers as engineered backfill systems to divert water away from radioactive waste potentially stored in a Yucca Mountain emplacement drift is investigated. We designed and conducted a flow visualization experiment to investigate capillary barrier performance in this context. A two-dimensional, thin slab, test system replicated the physical emplacement drift to one-quarter scale (1.4-m diameter) and included the simulated drift wall, waste canister, pedestal, capillary barrier backfill, and host-rock fracture system. Water was supplied at the top of the simulated drift and allowed to discharge by way of wicks located along the left wall of the cell (simulated fractures) or by a gravity drain at the bottom of the right side (simulated impermeable rock with floor drain). Photographs captured the migration of water and a blue dye tracer within the system, analytical balances measured the mass balance of water, while tensiometers measured the capillary pressure at numerous locations. Of particular concern to this test was the drainage of the capillary barrier, which terminates against the drift wall. We found that while the simulated fractures (left side) and drain (right side) each influenced the performance of the capillary barrier at early time, they had little differential affect at later times. Also of concern was the small disparity in capillary properties between the fine and coarse layer (limited by the need of a fine-grained material that would not filter into the coarse layer under dry conditions). While the capillary barrier was able to divert the majority of flow toward the edges of the system and away from the simulated waste canister, the barrier did not preclude flow in the coarse layer, which was noted to be visually wet next to the waste canister on day 92 and was continuing to take on water at termination on day 112. PMID:12714296

  7. Visualization experiment to investigate capillary barrier performance in the context of a Yucca Mountain emplacement drift

    NASA Astrophysics Data System (ADS)

    Tidwell, Vincent C.; Glass, Robert J.; Chocas, Connie; Barker, Glenn; Orear, Lee

    2003-05-01

    The use of capillary barriers as engineered backfill systems to divert water away from radioactive waste potentially stored in a Yucca Mountain emplacement drift is investigated. We designed and conducted a flow visualization experiment to investigate capillary barrier performance in this context. A two-dimensional, thin slab, test system replicated the physical emplacement drift to one-quarter scale (1.4-m diameter) and included the simulated drift wall, waste canister, pedestal, capillary barrier backfill, and host-rock fracture system. Water was supplied at the top of the simulated drift and allowed to discharge by way of wicks located along the left wall of the cell (simulated fractures) or by a gravity drain at the bottom of the right side (simulated impermeable rock with floor drain). Photographs captured the migration of water and a blue dye tracer within the system, analytical balances measured the mass balance of water, while tensiometers measured the capillary pressure at numerous locations. Of particular concern to this test was the drainage of the capillary barrier, which terminates against the drift wall. We found that while the simulated fractures (left side) and drain (right side) each influenced the performance of the capillary barrier at early time, they had little differential affect at later times. Also of concern was the small disparity in capillary properties between the fine and coarse layer (limited by the need of a fine-grained material that would not filter into the coarse layer under dry conditions). While the capillary barrier was able to divert the majority of flow toward the edges of the system and away from the simulated waste canister, the barrier did not preclude flow in the coarse layer, which was noted to be visually wet next to the waste canister on day 92 and was continuing to take on water at termination on day 112.

  8. 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.

    2001-05-01

    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.

  9. Visualization tools for model/data comparisons and decision making during the Monterey Bay 2006 experiment.

    NASA Astrophysics Data System (ADS)

    Pawlowski, L.; Kolber, D.; Godin, M.; Chavez, F. P.

    2006-12-01

    During summer 2006, almost 100 different oceanographic sensors have captured for more than one month the properties of the waters of the Californian Central Coast. Data were assimilated in quasi-real time by three hydrodynamical models to forecast the evolution of the local conditions such as currents, sea water temperature, salinity and to adapt accordingly the sampling strategy of the involved unmanned vehicles (AUV, gliders). Due to the high diversity of data and models (sources, file structures, time and spatial coverage, periodicity of sampling), the collected informations were first converted into a standardized format which allows one to quickly find and extract the relevant variables from the main data server of the experiment. Visualization softwares were developed to provide live maps of the latest locations of instruments, surface plots and vertical transects of currents, temperature and salinity from data and models. These products were mainly used for decision making, for model intercomparison and to evaluate the quality of the data assimilation process for each model. Plots were updated several times a day and automatically posted on an internet collaborative portal. Softwares were adaptive in regards of the availability of simulations and datasets from satellite, aircraft, robotic vehicles, research vessels, moorings, drifters Their modular structures allowed a quick implementation of new instruments during the experiment. Profiles from gliders and AUV served as references for intercomparisons between models for salinity and temperature. As simulations were not synchronized between models, the involved algorithm selected, for all gliders, relevant portions of their tracks to serve as references for model intercomparison. These portions were delimited to prioritize the comparison for each model between observations and nowcasts/hindcasts and also to evaluate the loss of forecasting capabilities with time. We provide here several examples of these

  10. A Small Motor Cortex Lesion Abolished Ocular Dominance Plasticity in the Adult Mouse Primary Visual Cortex and Impaired Experience-Dependent Visual Improvements

    PubMed Central

    Pielecka-Fortuna, Justyna; Kalogeraki, Evgenia; Greifzu, Franziska; Löwel, Siegrid

    2015-01-01

    It was previously shown that a small lesion in the primary somatosensory cortex (S1) prevented both cortical plasticity and sensory learning in the adult mouse visual system: While 3-month-old control mice continued to show ocular dominance (OD) plasticity in their primary visual cortex (V1) after monocular deprivation (MD), age-matched mice with a small photothrombotically induced (PT) stroke lesion in S1, positioned at least 1 mm anterior to the anterior border of V1, no longer expressed OD-plasticity. In addition, in the S1-lesioned mice, neither the experience-dependent increase of the spatial frequency threshold (“visual acuity”) nor of the contrast threshold (“contrast sensitivity”) of the optomotor reflex through the open eye was present. To assess whether these plasticity impairments can also occur if a lesion is placed more distant from V1, we tested the effect of a PT-lesion in the secondary motor cortex (M2). We observed that mice with a small M2-lesion restricted to the superficial cortical layers no longer expressed an OD-shift towards the open eye after 7 days of MD in V1 of the lesioned hemisphere. Consistent with previous findings about the consequences of an S1-lesion, OD-plasticity in V1 of the nonlesioned hemisphere of the M2-lesioned mice was still present. In addition, the experience-dependent improvements of both visual acuity and contrast sensitivity of the open eye were severely reduced. In contrast, sham-lesioned mice displayed both an OD-shift and improvements of visual capabilities of their open eye. To summarize, our data indicate that even a very small lesion restricted to the superficial cortical layers and more than 3mm anterior to the anterior border of V1 compromised V1-plasticity and impaired learning-induced visual improvements in adult mice. Thus both plasticity phenomena cannot only depend on modality-specific and local nerve cell networks but are clearly influenced by long-range interactions even from distant brain

  11. Impact of Surface Roughness on Capillary Trapping Using 2D-Micromodel Visualization Experiments

    NASA Astrophysics Data System (ADS)

    Geistlinger, Helmut; Attaei-Dadavi, Iman; Vogel, Hans-Jörg

    2016-04-01

    According to experimental observations, capillary trapping is strongly dependent on the roughness of the pore-solid interface. We performed imbibition experiments in the range of capillary numbers (Ca) from 10^-6 to 5x10^-5 using 2D-micromodels, which exhibit a rough surface. The microstructure comprises a double-porosity structure with pronounced macropores. The dynamics of precursor thin-film flow and its importance for capillary trapping is studied. For the first time Thin-Film Dynamics and the Complex Interplay of Thin Film- and Corner Flow for Snap-off Trapping is visualized using fluorescence microscopy. The experimental data for thin-film flow advancement show a square-root time dependence. Contrary to smooth surfaces, we prove by strict thermodynamical arguments that complete wetting is possible in a broad range of contact angles (0 - 90°). We develop a pore-scale model, which describes the front dynamics of thin-film flow on rough surfaces. Furthermore, contact angle hysteresis is considered for rough surfaces. We conduct a comprehensive cluster analysis, studying the influence of viscous forces (capillary number) and buoyancy forces (bond number) on cluster size distribution and comparing the results with predictions from percolation theory. We found that our experimental results agree with theoretical results of percolation theory for Ca = 10^-6: (i) a universal power-like cluster size distribution, (ii) the linear surface-volume relationship of trapped clusters, and (iii) the existence of the cut-off correlation length for the maximal cluster height. The good agreement is a strong argument that the experimental cluster size distribution is caused by a percolation-like trapping process (Ordinary Percolation). [1] H. Geistlinger, I. Ataei-Dadavi, S. Mohammadian, and H.-J. Vogel (2015) The Impact of Pore structure and Surface Roughness on Capillary Trapping for 2D- and 3D-porous media: Comparison with Percolation theory. Special issue: Applications of

  12. Experience-dependent development of perineuronal nets and chondroitin sulfate proteoglycan receptors in mouse visual cortex.

    PubMed

    Ye, Qian; Miao, Qing-Long

    2013-08-01

    Perineuronal nets (PNNs) are extracellular matrix structures consisting of chondroitin sulfate proteoglycans (CSPGs), hyaluronan, link proteins and tenascin-R (Tn-R). They enwrap a subset of GABAergic inhibitory interneurons in the cerebral cortex and restrict experience-dependent cortical plasticity. While the expression profile of PNN components has been widely studied in many areas of the central nervous system of various animal species, it remains unclear how these components are expressed during the postnatal development of mouse primary visual cortex (V1). In the present study, we characterized the developmental time course of the formation of PNNs in the mouse primary visual cortex, using the specific antibodies against the two PNN component proteins aggrecan and tenascin-R, or the lectin Wisteria floribunda agglutinin (WFA) that directly binds to glycosaminoglycan chains of chondroitin sulfate proteoglycans (CSPGs). We found that the fluorescence staining signals of both the WFA staining and the antibody against aggrecan rapidly increased in cortical neurons across layers 2-6 during postnatal days (PD) 10-28 and reached a plateau around PD42, suggesting a full construction of PNNs by the end of the critical period. Co-staining with antibodies to Ca(2+) binding protein parvalbumin (PV) demonstrated that the majority of PNN-surrounding cortical neurons are immunoreactive to PV. Similar expression profile of another PNN component tenascin-R was observed in the development of V1. Dark rearing of mice from birth significantly reduced the density of PNN-surrounding neurons. In addition, the expression of two recently identified CSPG receptors - Nogo receptor (NgR) and leukocyte common antigen-related phosphatase (LAR), showed significant increases from PD14 to PD70 in layer 2-6 of cortical PV-positive interneurons in normal reared mice, but decreased significantly in dark-reared ones. Taken together, these results suggest that PNNs form preferentially in cortical

  13. The Importance of Art Viewing Experiences in Early Childhood Visual Arts: The Exploration of a Master Art Teacher's Strategies for Meaningful Early Arts Experiences

    ERIC Educational Resources Information Center

    Eckhoff, Angela

    2008-01-01

    The visual arts can be an important and rich domain of learning for young children. In PreK education, The Task Force on Children's Learning and the Arts: Birth to Age Eight ("Young children and the arts: Making creative connections", Washington, DC: Arts Education Partnership, 1998) recommends that art experiences for young children include…

  14. 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…

  15. 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. PMID:24993636

  16. Sleep and Sex: What Can Go Wrong? A Review of the Literature on Sleep Related Disorders and Abnormal Sexual Behaviors and Experiences

    PubMed Central

    Schenck, Carlos H.; Arnulf, Isabelle; Mahowald, Mark W.

    2007-01-01

    Study Objectives: To formulate the first classification of sleep related disorders and abnormal sexual behaviors and experiences. Design: A computerized literature search was conducted, and other sources, such as textbooks, were searched. Results: Many categories of sleep related disorders were represented in the classification: parasomnias (confusional arousals/sleepwalking, with or without obstructive sleep apnea; REM sleep behavior disorder); sleep related seizures; Kleine-Levin syndrome (KLS); severe chronic insomnia; restless legs syndrome; narcolepsy; sleep exacerbation of persistent sexual arousal syndrome; sleep related painful erections; sleep related dissociative disorders; nocturnal psychotic disorders; miscellaneous states. Kleine-Levin syndrome (78 cases) and parasomnias (31 cases) were most frequently reported. Parasomnias and sleep related seizures had overlapping and divergent clinical features. Thirty-one cases of parasomnias (25 males; mean age, 32 years) and 7 cases of sleep related seizures (4 males; mean age, 38 years) were identified. A full range of sleep related sexual behaviors with self and/or bed partners or others were reported, including masturbation, sexual vocalizations, fondling, sexual intercourse with climax, sexual assault/rape, ictal sexual hyperarousal, ictal orgasm, and ictal automatism. Adverse physical and/or psychosocial effects from the sleepsex were present in all parasomnia and sleep related seizure cases, but pleasurable effects were reported by 5 bed partners and by 3 patients with sleep related seizures. Forensic consequences were common, occurring in 35.5% (11/31) of parasomnia cases, with most (9/11) involving minors. All parasomnias cases reported amnesia for the sleepsex, in contrast to 28.6% (2/7) of sleep related seizure cases. Polysomnography (without penile tumescence monitoring), performed in 26 of 31 parasomnia cases, documented sexual moaning from slow wave sleep in 3 cases and sexual intercourse during

  17. The Influence of Visual Experience on the Ability to Form Spatial Mental Models Based on Route and Survey Descriptions

    ERIC Educational Resources Information Center

    Noordzij, Matthijs L.; Zuidhoek, Sander; Postma, Albert

    2006-01-01

    The purpose of the present study is twofold: the first objective is to evaluate the importance of visual experience for the ability to form a spatial representation (spatial mental model) of fairly elaborate spatial descriptions. Secondly, we examine whether blind people exhibit the same preferences (i.e. level of performance on spatial tasks) as…

  18. 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…

  19. EXEL; Experience for Children in Learning. Parent-Directed Activities to Develop: Oral Expression, Visual Discrimination, Auditory Discrimination, Motor Coordination.

    ERIC Educational Resources Information Center

    Behrmann, Polly; Millman, Joan

    The activities collected in this handbook are planned for parents to use with their children in a learning experience. They can also be used in the classroom. Sections contain games designed to develop visual discrimination, auditory discrimination, motor coordination and oral expression. An objective is given for each game, and directions for…

  20. 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…

  1. The Effects of Visual Experience and Training in Raised-Line Materials on the Mental Spatial Imagery of Blind Persons

    ERIC Educational Resources Information Center

    Dulin, David; Hatwell, Yvette

    2006-01-01

    Visual experience improved performances of blind adults in mental rotation and mental representation of the path of a spot. Congenitally blind participants with high expertise in graphic material performed better than two categories of nonexpert participants--those who became blind early in their lives versus those who became blind later in their…

  2. Using ICT at an Open Distance Learning (ODL) Institution in South Africa: The Learning Experiences of Students with Visual Impairments

    ERIC Educational Resources Information Center

    Mokiwa, S. A.; Phasha, T. N.

    2012-01-01

    For students with visual impairments, Information and Communication Technology (ICT) has become an important means through which they can learn and access learning materials at various levels of education. However, their learning experiences in using such form of technologies have been rarely documented, thus suggests society's lack of…

  3. Experiences using Visualization Techniques to Present Requirements, Risks to Them, and Options for Risk Mitigation

    NASA Technical Reports Server (NTRS)

    Feather, Martin S.; Cornford, Steven L.; Kiper, James D.; Menzies, Tim

    2006-01-01

    For several years we have been employing a risk-based decision process to guide development and application of advanced technologies, and for research and technology portfolio planning. The process is supported by custom software, in which visualization plays an important role. During requirements gathering, visualization is used to help scrutinize the status (completeness, extent) of the information. During decision making based on the gathered information, visualization is used to help decisionmakers understand the space of options and their consequences. In this paper we summarize the visualization capabilities that we have employed, indicating when and how they have proven useful.

  4. Visualizing skin effects in conductors with MRI: (7)Li MRI experiments and calculations.

    PubMed

    Ilott, Andrew J; Chandrashekar, S; Klöckner, Andreas; Chang, Hee Jung; Trease, Nicole M; Grey, Clare P; Greengard, Leslie; Jerschow, Alexej

    2014-08-01

    While experiments on metals have been performed since the early days of NMR (and DNP), the use of bulk metal is normally avoided. Instead, often powders have been used in combination with low fields, so that skin depth effects could be neglected. Another complicating factor of acquiring NMR spectra or MRI images of bulk metal is the strong signal dependence on the orientation between the sample and the radio frequency (rf) coil, leading to non-intuitive image distortions and inaccurate quantification. Such factors are particularly important for NMR and MRI of batteries and other electrochemical devices. Here, we show results from a systematic study combining rf field calculations with experimental MRI of (7)Li metal to visualize skin depth effects directly and to analyze the rf field orientation effect on MRI of bulk metal. It is shown that a certain degree of selectivity can be achieved for particular faces of the metal, simply based on the orientation of the sample. By combining rf field calculations with bulk magnetic susceptibility calculations accurate NMR spectra can be obtained from first principles. Such analyses will become valuable in many applications involving battery systems, but also metals, in general. PMID:25036296

  5. Numerical Experiments and Flow Visualization of Drag Reduction using EMHD Control

    NASA Astrophysics Data System (ADS)

    O'Sullivan, Peter; Biringen, Sedat

    1998-11-01

    Turbulent channel flow of saltwater is studied numerically with the aim of achieving drag reduction via EMHD control using the Lorentz force of flush-mounted microtiles similar to those developed by Bandyopadhyay at NUWC. Our prior numerical simulations indicated significant local spatial deviations on the time-average skin friction (± 10%) in the vicinity of the control actuators. However, there was negligible net viscous drag reduction (<1%). To better understand the physics of the interaction of the controlling Lorentz force with the passage of advecting burst events we have performed short-duration simulations. We implement a burst detection scheme based on that of Alfredsson and Johansson (1984) in order to locate and track the strongest Q2 events in the flow. Subsequently, we compare the evolution of these structures, both with and without EMHD control. We find that the specific designs we have studied do not succeed in reducing the primary Reynolds stress as a burst advects above an actuator. Via flow visualization of large-scale coherent structures we find that the classic hairpin vortices which populate the boundary layer are not significantly affected by the applied control - apart from a temporary spatial phase shift. We will present our findings of these numerical experiments and discuss the prospects for a more successful design and control strategy.

  6. Numerical Experiments and Flow Visualization of Drag Reduction using EMHD Control

    NASA Astrophysics Data System (ADS)

    O'Sullivan, Peter; Biringen, Sedat

    1997-11-01

    Turbulent channel flow of saltwater is studied numerically with the aim of achieving drag reduction via EMHD control using the Lorentz force of flush-mounted microtiles developed by Bandyopadhyay at NUWC. Previous numerical simulations have indicated significant local spatial deviations on the time-average skin friction (± 10%) in the vicinity of the control actuators. However, there was only negligible net viscous drag reduction (<2%). In an attempt to better understand the physics of the interaction of the controlling Lorentz force with the passage of an advecting incipient burst we have performed numerous short simulations. We scanned a wide variety of archival data from our previous simulations and extracted a good sample of burst ``candidate'' initial conditions. We then advanced these flows forward in time both with and without control. We studied the resulting burst/control dynamics with respect to control strength, duration, temporal frequency, spanwise offset and streamwise spacing of the microtiles. The spatio-temporal response of the burst and sweep structures is crucial to a successful drag reduction strategy. By identifying the key parameters in the control space we aim to narrow the focus of the design problem. We will present our findings of these numerical experiments which are based on data analysis together with flow visualization.

  7. Visualization experiments of biofilm growth in the presence of carbon dioxide

    NASA Astrophysics Data System (ADS)

    Manariotis, I. D.; Sygouni, V.; Chrysikopoulos, C. V.

    2013-12-01

    Capturing and storing CO2 emissions in properly selected deep geologic formations is considered a promising solution for the reduction of CO2 in the atmosphere. However, CO2 leakage may potentially occur from the storage geologic formation. Partition of CO2 in water may result in pH decrease. This change in aqueous phase may contribute to solubilization of undesired heavy metals from the solid matrix. In this work we investigate experimentally the impact of CO2 to shallow groundwater systems. A series of visualization experiments in a glass-etched micromodel were performed in order to estimate the effect of CO2 on biofilm formation. Biofilms were developed using Pseudomonas putida. Nutrient saturated with CO2 was injected in the micromodel through an inlet port, and fluid samples were collected at the outlet port. The transient growth of the biofilm was monitored by taking high-resolution digital photographs at various times, and the effect of CO2 on biofilm growth was estimated.

  8. Visualization of the meridian of traditional Chinese medicine with electrical impedance tomography: An initial experience

    NASA Astrophysics Data System (ADS)

    Cao, Yanli; Lu, Xiaozuo; Wang, Xuemin

    2010-04-01

    The meridian is a concept central to traditional Chinese medical techniques such as acupuncture. There is no physically verifiable anatomical or histological basis for the existence of meridians. In Chinese medicine, the meridians are channels along which the energy of the psychological system is considered to flow. It has been proven that the resistance along the meridian channels is lower compared to other paths. Based on this knowledge, we proposed using electrical impedance tomography (EIT) to visualize the meridians of human being. A simplified three dimensional (3D) mathematical model of the forearm developed. Current was injected in the direction perpendicular to the cross-section where eight electrodes were equally placed around the surface of the forearm for the voltage measurements. The model was solved using Finite Element Method (FEM) and dynamic image was reconstructed using truncated singular value decomposition (TSVD) regularization method. The conductivity distributions were compared with different current injections, along the meridian channel and channels around respectively. We also conducted experiments on models and the meridians were shown in final reconstructed images.

  9. Visualizing skin effects in conductors with MRI: 7Li MRI experiments and calculations

    NASA Astrophysics Data System (ADS)

    Ilott, Andrew J.; Chandrashekar, S.; Klöckner, Andreas; Chang, Hee Jung; Trease, Nicole M.; Grey, Clare P.; Greengard, Leslie; Jerschow, Alexej

    2014-08-01

    While experiments on metals have been performed since the early days of NMR (and DNP), the use of bulk metal is normally avoided. Instead, often powders have been used in combination with low fields, so that skin depth effects could be neglected. Another complicating factor of acquiring NMR spectra or MRI images of bulk metal is the strong signal dependence on the orientation between the sample and the radio frequency (rf) coil, leading to non-intuitive image distortions and inaccurate quantification. Such factors are particularly important for NMR and MRI of batteries and other electrochemical devices. Here, we show results from a systematic study combining rf field calculations with experimental MRI of 7Li metal to visualize skin depth effects directly and to analyze the rf field orientation effect on MRI of bulk metal. It is shown that a certain degree of selectivity can be achieved for particular faces of the metal, simply based on the orientation of the sample. By combining rf field calculations with bulk magnetic susceptibility calculations accurate NMR spectra can be obtained from first principles. Such analyses will become valuable in many applications involving battery systems, but also metals, in general.

  10. Laboratory flow experiments for visualizing carbon dioxide-induced, density-driven brine convection

    SciTech Connect

    Kneafsey, T.; Pruess, K.

    2009-09-01

    Injection of carbon dioxide (CO{sub 2}) into saline aquifers confined by low-permeability cap rock will result in a layer of CO{sub 2} overlying the brine. Dissolution of CO{sub 2} into the brine increases the brine density, resulting in an unstable situation in which more-dense brine overlies less-dense brine. This gravitational instability could give rise to density-driven convection of the fluid, which is a favorable process of practical interest for CO{sub 2} storage security because it accelerates the transfer of buoyant CO{sub 2} into the aqueous phase, where it is no longer subject to an upward buoyant drive. Laboratory flow visualization tests in transparent Hele-Shaw cells have been performed to elucidate the processes and rates of this CO{sub 2} solute-driven convection (CSC). Upon introduction of CO{sub 2} into the system, a layer of CO{sub 2}-laden brine forms at the CO{sub 2}-water interface. Subsequently, small convective fingers form, which coalesce, broaden, and penetrate into the test cell. Images and time-series data of finger lengths and wavelengths are presented. Observed CO{sub 2} uptake of the convection system indicates that the CO{sub 2} dissolution rate is approximately constant for each test and is far greater than expected for a diffusion-only scenario. Numerical simulations of our system show good agreement with the experiments for onset time of convection and advancement of convective fingers. There are differences as well, the most prominent being the absence of cell-scale convection in the numerical simulations. This cell-scale convection observed in the experiments is probably initiated by a small temperature gradient induced by the cell illumination.

  11. The Efficacy of Family Camp Experience for Families Who Have Children with Visual Impairments. Research Report

    ERIC Educational Resources Information Center

    Day, Janice Neibaur; Kleinschmidt, Julia

    2005-01-01

    This study was designed to address the paucity of research on the efficacy of camps for children with visual impairments and their families. The study evaluated the performance of a two-day camp for families with young visually impaired children at the Utah Schools for the Deaf and the Blind whose program was based on perceived family needs and…

  12. The Nature of Experience Determines Object Representations in the Visual System

    ERIC Educational Resources Information Center

    Wong, Yetta K.; Folstein, Jonathan R.; Gauthier, Isabel

    2012-01-01

    Visual perceptual learning (PL) and perceptual expertise (PE) traditionally lead to different training effects and recruit different brain areas, but reasons for these differences are largely unknown. Here, we tested how the learning history influences visual object representations. Two groups were trained with tasks typically used in PL or PE…

  13. English Language Learners: Experiences of Teachers of Students with Visual Impairments Who Work with This Population

    ERIC Educational Resources Information Center

    Topor, Irene; Rosenblum, L. Penny

    2013-01-01

    Introduction: This article presents a study that gathered data from 66 teachers of students with visual impairments about their preparation to work with children who are visually impaired and are learning English, and their knowledge of instructional strategies and methods of instruction. Methods: An online five-part survey was available to…

  14. 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

  15. 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.

  16. Visual scoring of clots in foremilk.

    PubMed

    Rasmussen, Morten D

    2005-11-01

    The necessary unequivocal and generally accepted definitions of normal and abnormal milk are not available. A precise definition is needed in order for companies to develop sensors to detect and sort abnormal milk at the time of milking. Experts at a workshop defined abnormal milk to be that from cows whose foremilk had changed in homogeneity or was coloured by blood. The objectives of this paper were: firstly, to explore how different groups of people scored the appearance of foremilk; and secondly, to develop a method suitable as an objective reference for testing of manual and automatic detection systems. Consumers, farmers and advisors did not agree on the visual appearance of normal, watery, clotty milk, or milk with blood, and experience is needed to score the visual appearance of foremilk correctly. It seems reasonable to expect a sensitivity of at least 70% for detection of abnormal milk during foremilking. Filter sizes 0.05, 0.07, 0.1, 0.2, 0.5, 1.0, and 2.0 mm were used to filter milk from cows with visually abnormal foremilk. If clots appeared in the foremilk, clots appeared on all size filters, but the filter with pore size 0.1 mm was the easiest to read and work with. The filter method is not reliable in identifying quarters with watery, yellowish, or bloody milk, whereas the method seems consistent, and at least as good as scoring of visual appearance in finding clots in the milk. Clots should show clearly on the filter to be counted as abnormal milk. All clinical cases with clots in the foremilk can be found on the filter and such cases have high somatic cell count (SCC). Both trained and untrained persons using the filter method can score normal and abnormal foremilk with a high specificity (>90%) and a high sensitivity (>80%). The filter method is recommended as a reference for scoring the homogeneity of foremilk. PMID:16223455

  17. The suspended sediment boundary condition: new insight from high-speed visualization experiments

    NASA Astrophysics Data System (ADS)

    Schmeeckle, M. W.

    2001-12-01

    Considerable attention has been given to correctly calculating the interior portion of suspended sediment concentration profiles by including such effects as separation-generated turbulence structures and density stratification. Yet, because the sediment concentration is generally highest near the bed, prediction of the suspended sediment flux is only as good as the near-bed suspended sediment boundary condition. However, current knowledge of the physical process of suspended sediment entrainment and disentrainment is very poor. In order to obtain a basic understanding of this process, near-bed visualization experiments of combined bedload and suspended load transport were performed in a laboratory flume. Video sequences of the 1mm bedload and 0.1mm suspended load grains were taken at a rate of 250 frames per second and a shutter speed of 0.1msec. Illumination was provided by a 50W near-infrared laser diode sheet having a thickness of 1mm. Individual bedload and suspended load particles could be tracked in the video images. For hydraulically-smooth flows it has been shown that suspended sediment entrainment is primarily associated with the turbulent ejection events at the downstream ends of low-speed streaks. Ejections are characterized by vertical motion of fluid having smaller than average downstream momentum. By contrast, in hydraulically-rough flows with bedload motion, the low-speed streak-ejection structure has not been found. The high-speed video experiments reveal that higher than average near-bed concentrations of suspended sediment are correlated with higher than average fluxes of bedload. This suggests that suspended sediment entrainment results from the entrainment of bedload, and is not result of ejection events. Indeed, high rates of bedload entrainment are predominantly associated with higher than average downstream velocity. Thus, suspended sediment entrainment in the presence of bedload appears to occur by the exhumation of suspended-size grains as

  18. Miscible and immiscible experiments on the Rayleigh-Taylor instability using simultaneous planar laser induced fluorescence and backlight visualization.

    NASA Astrophysics Data System (ADS)

    Mokler, Matthew; Roberts, Michael; Jacobs, Jeffrey

    2012-11-01

    Incompressible Rayleigh-Taylor instability experiments are presented in which two stratified liquids having Atwood number of 0.2 are accelerated in a vertical linear induction motor driven drop tower. A test sled having only vertical freedom of motion contains the experiment tank and visualization equipment. The sled is positioned at the top of the tower within the linear motors and accelerated downward causing the initially stable interface to be unstable and allowing the Rayleigh-Taylor instability to develop. Experiments are presented with and without forced initial perturbations produced by vertically oscillating the test sled prior to the start of acceleration. Half of the experimental tank is visualized using a 445nm laser light source that illuminates a fluorescent dye mixed in one of the fluids. The other half is illuminated with a white backlight. The resulting images are recorded using a monochromatic high speed video camera allowing for the measurement of spike and bubble mixing layer growth rates for both visualization techniques in a single experiment.

  19. Changes in and Efficacies of Indications for Invasive Prenatal Diagnosis of Cytogenomic Abnormalities: 13 Years of Experience in a Single Center

    PubMed Central

    Meng, Jinlai; Matarese, Chelsea; Crivello, Julianna; Wilcox, Katherine; Wang, Dongmei; DiAdamo, Autumn; Xu, Fang; Li, Peining

    2015-01-01

    Background Because the future application of cell-free fetal DNA screening is expected to dramatically improve the diagnostic yield and reduce unnecessary invasive procedures, it is time to summarize the indications of invasive prenatal diagnosis. This retrospective study was performed to evaluate the changes and efficacies of indications of invasive procedures for detecting cytogenomic abnormalities from 2000 to 2012. Material/Methods From our regional obstetric unit, 7818 invasive procedures were referred by indications of advance maternal age (AMA), abnormal ultrasound findings (aUS), abnormal maternal serum screening (aMSS), and family history (FH). Chromosome, fluorescence in situ hybridization (FISH), and array comparative genomic hybridization (aCGH) analyses were performed on chorionic villus sampling (CVS) and amniotic fluid (AF) specimens at the Yale Cytogenetics Laboratory. The abnormal findings from single or combined indications were compared to evaluate the diagnostic yield. Results The annual caseload declined by 57.2% but the diagnostic yield increased from 7.2% to 13.4%. Chromosomal and genomic abnormalities were detected in 752 cases (9.6%, 752/7818) and 12 cases (4%, 12/303), respectively. Significantly decreased AMA referrals and increased aUS and aMSS referrals were noted. The top 3 indications by diagnostic yield were AMA/aUS (51.4% for CVS, 24.2% for AF), aUS (34.7% for CVS, 14.5% for AF), and AMA/aMSS (17.8% for CVS, 9.9% for AF). Conclusions Over a period of 13 years, the indication of aMSS and aUS were increasing while AMA was decreasing for prenatal diagnosis of cytogenomic abnormalities, and there was a continuous trend of reduced invasive procedures. Prenatal evaluation using AMA/aUS was the most effective in detecting chromosomal abnormalities, but better indications for genomic abnormalities are needed. PMID:26143093

  20. Dysregulation of synaptic proteins, dendritic spine abnormalities and pathological plasticity of synapses as experience-dependent mediators of cognitive and psychiatric symptoms in Huntington's disease.

    PubMed

    Nithianantharajah, J; Hannan, A J

    2013-10-22

    Huntington's disease (HD) is an autosomal dominant tandem repeat expansion disorder involving cognitive, psychiatric and motor symptoms. The expanded trinucleotide (CAG) repeat leads to an extended polyglutamine tract in the huntingtin protein and a subsequent cascade of molecular and cellular pathogenesis. One of the key features of neuropathology, which has been shown to precede the eventual loss of neurons in the cerebral cortex, striatum and other areas, are changes to synapses, including the dendritic protrusions known as spines. In this review we will focus on synapse and spine pathology in HD, including molecular and experience-dependent aspects of pathogenesis. Dendritic spine pathology has been found in both the human HD brain at post mortem as well as various transgenic and knock-in animal models. These changes may help explain the symptoms in HD, and synaptopathy within the cerebral cortex may be particularly important in mediating the psychiatric and cognitive manifestations of this disease. The earliest stages of synaptic dysfunction in HD, as assayed in various mouse models, appears to involve changes in synaptic proteins and associated physiological abnormalities such as synaptic plasticity deficits. In mouse models, synaptic and cortical plasticity deficits have been directly correlated with the onset of cognitive deficits, implying a causal link. Furthermore, following the discovery that environmental enrichment can delay onset of affective, cognitive and motor deficits in HD transgenic mice, specific synaptic molecules shown to be dysregulated by the polyglutamine-induced toxicity were also found to be beneficially modulated by environmental stimulation. This identifies potential molecular targets for future therapeutic developments to treat this devastating disease. PMID:22633949

  1. Effects of Fluoxetine and Visual Experience on Glutamatergic and GABAergic Synaptic Proteins in Adult Rat Visual Cortex1,2,3

    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

  2. Comparing distances in mental images constructed from visual experience or verbal descriptions: the impact of survey versus route perspective.

    PubMed

    Péruch, Patrick; Chabanne, Vanessa; Nesa, Marie-Pascale; Thinus-Blanc, Catherine; Denis, Michel

    2006-11-01

    Mental images constructed after visual examination of a spatial configuration or after processing a verbal description of that configuration have been shown to share similar properties, in particular the capacity to preserve metric information contained in the configuration represented. In the present study, we investigated the properties of mental images constructed under learning conditions resulting from the combination of a visual or a verbal mode of acquisition and a survey or route perspective. Participants memorized a virtual environment (a garden containing six objects) under one of four learning conditions: (a) viewing a map of the garden (visual-survey); (b) viewing a video presentation of a journey along the path around the garden (visual-route); (c) listening to a verbal description of the map of the garden (verbal-survey); and (d) listening to a verbal description of the journey around the garden (verbal-route). The participants were then invited to compare the distances separating objects in the garden mentally. Experiment 1, where the pairs of distances to be compared had a common starting point, revealed that the frequency of correct responses was higher, and response times were shorter when participants had learned about the environment visually rather than by a verbal description. The conditions involving a survey perspective resulted in a higher frequency of correct responses and shorter response times than those involving a route perspective. Lastly, a symbolic distance effect was obtained in the first three conditions, in that the greater the difference between the two distances being compared, the higher the frequency of correct responses, and the shorter the response times. Experiment 2, where the pairs of distances had different starting points, replicated these results, although longer response times revealed that the comparison process was more costly. Taken together, these findings support the view that mental spatial representations

  3. Science for all: Experiences and outcomes of students with visual impairment in a guided inquiry-based classroom

    NASA Astrophysics Data System (ADS)

    Rooks, Deborah L.

    The purpose of this study was to examine instructional experiences of students with visual impairment in an guided inquiry-based science classroom. Drawing from social constructive perspectives about teaching and learning, I focused on the initial attempts of students to participate fully in an inquiry-based astronomy unit. The astronomy unit incorporated features of project-based science inquiry and aligned with national standards. This study described the opportunities provided to and challenges faced by students with visual impairment as they participated in the guided inquiry-based learning environment. Additionally, discursive practices of students including student-generated questions, student discussions, and students' science notebook writing were examined. Also, students' alternative conceptions about scientific phenomena and changes in students' thinking during the course of instruction, if any, were described. Methods of data collection included classroom observations, video records, pre- and post-curriculum assessments, attitudes toward science measurement, student interviews, and student artifacts (i.e., science notebook entries, student-constructed models). Findings showed that student learning was enhanced when the instructor-researcher guided students in accomplishing inquiry tasks and in making sense of their inquiry experiences. Additionally, the use of appropriate reflective prompts assisted students with visual impairment to fully participate in the writing tasks of the inquiry-based learning environment. Results suggested that the quantity and quality of student-generated questions increased with extended inquiry instruction. Also, students used questions to not only establish verbal communication, but to elaborate on their own thinking and expand or explain the thinking of others. Findings suggested also that students with visual impairment have similar alternative frameworks about scientific phenomena (i.e., causes of lunar phases, reason for

  4. 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

  5. Visual experience prevents dysregulation of GABAB receptor-dependent short-term depression in adult superior colliculus

    PubMed Central

    Balmer, Timothy S.

    2015-01-01

    Progressive loss of plasticity during development prevents refined circuits from regressing to an immature state and is thought to depend on maturation of GABAergic inhibition. For example, a gradual reduction in size of visual receptive fields (RFs) occurs in the superior colliculus (SC) during development. Maintenance of the refined state throughout adulthood requires early light exposure. Here we investigate the potential role of changes in long- or short-term plasticity in experience-dependent maintenance of refined RFs. Using an acute SC slice preparation, we found that long-term plasticity was not affected by visual deprivation, indicating that it does not underlie deprivation-induced RF enlargement. In contrast, visual deprivation altered short-term plasticity in an unexpected way. Specifically, GABAB receptor (GABABR)-mediated paired pulse depression was increased in slices from dark-reared animals. This increase was mimicked by GABAAR blockade in slices from normally reared animals, suggesting that experience-dependent maintenance of GABAAR function prevents an increase in probability of neurotransmitter release. GABABR-mediated short-term depression in response to strong stimulation (such as occurs during vision) was reduced in slices from dark-reared animals. This change was mimicked in slices from normal animals by reducing GABA release. These results are consistent with the hypothesis that early visual experience maintains GABAergic inhibition and prevents later deprivation-induced alterations of short-term depression in SC. Identifying how plasticity is restricted in mature circuits could guide therapies to enhance recovery of function in adults. PMID:25568162

  6. 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. PMID:26325202

  7. Visualization and the Experience of Poetry: A Study of Selected Variables in Reader Response.

    ERIC Educational Resources Information Center

    Dilworth, Collett Broyles

    This study is designed to investigate the relationship between the extent of visualization of poetically elicited mental images (V) and five other variables involved in response to poetry: extent of verbal interpretation of the meaning of poetry; extent of recall of poetry; accuracy of recall of poetry; extent of liking of poetry; and level of…

  8. Engaging the Unengaged: Using Visual Images to Enhance Students' "Poli Sci 101" Experience

    ERIC Educational Resources Information Center

    Ulbig, Stacy

    2009-01-01

    As the nation witnesses a distinct decline in civic engagement among young adults, political science instructors across the nation face the formidable task of engaging students in lower-level, general education courses outside students' primary domain of interest. The research presented here seeks to understand if visually enhanced lecture…

  9. Mantid-Data analysis and visualization package for neutron scattering and μ SR experiments

    NASA Astrophysics Data System (ADS)

    Arnold, O.; Bilheux, J. C.; Borreguero, J. M.; Buts, A.; Campbell, S. I.; Chapon, L.; Doucet, M.; Draper, N.; Ferraz Leal, R.; Gigg, M. A.; Lynch, V. E.; Markvardsen, A.; Mikkelson, D. J.; Mikkelson, R. L.; Miller, R.; Palmen, K.; Parker, P.; Passos, G.; Perring, T. G.; Peterson, P. F.; Ren, S.; Reuter, M. A.; Savici, A. T.; Taylor, J. W.; Taylor, R. J.; Tolchenov, R.; Zhou, W.; Zikovsky, J.

    2014-11-01

    The Mantid framework is a software solution developed for the analysis and visualization of neutron scattering and muon spin measurements. The framework is jointly developed by software engineers and scientists at the ISIS Neutron and Muon Facility and the Oak Ridge National Laboratory. The objectives, functionality and novel design aspects of Mantid are described.

  10. Family Voices at Mealtime: Experiences with Young Children with Visual Impairment

    ERIC Educational Resources Information Center

    Smyth, Catherine A.; Spicer, Carol L.; Morgese, Zoe L.

    2014-01-01

    Infants with visual impairment often require additional interaction from adults to reinforce behaviors that lead to competency at mealtimes, but parental and professional confidence in teaching these skills is often limited. In the following collective case study, the authors, a speech/language pathologist (S/LP), occupational therapist (OT), and…

  11. On the delights of being an ex-cataract patient: Visual experiences before and after cataract operations; what they indicate

    NASA Astrophysics Data System (ADS)

    van Nes, Floris L.

    2014-02-01

    This paper is about changes in the author's visual perception over most of his lifetime, but in particular in the period before and after cataract operations. The author was myopic (-3D) until the operations, and emmetropic afterwards - with mild astigmatic aberrations that can be compensated with cylindrical spectacles, but in his case rarely are, because of the convenience of not needing to wear distance glasses in daily life anymore. The perceptual changes concern color vision, stereopsis and visual acuity. The post-cataract changes were partly expected, for example less yellow and more blue images, but partly wholly unexpected, and accompanied by feelings of excitement and pleasure; even delight. These unexpected changes were a sudden, strongly increased depth vision and the sensation of seeing suddenly sharper than ever before, mainly at intermediate viewing distances. The visual acuity changes occur after, exceptionally, his distance glasses are put on. All these sensations lasted or last only for a short time. Those concerning stereopsis were dubbed 'super depth', and were confined to the first two months after the second cataract operation. Those concerning acuity were termed 'super-sharpness impression'; SSI. These can be elicited more or less at will, by putting on the spectacles described; but will then disappear again, although the spectacles are kept on. Ten other ex-cataract patients have been interviewed on their post-operation experiences. The 'super-depth' and SSI experiences may be linked to assumed neurophysiological mechanisms such as the concept of Bayesian reweighting of perceptual criteria.

  12. Abnormal Head Position

    MedlinePlus

    ... cause. Can a longstanding head turn lead to any permanent problems? Yes, a significant abnormal head posture could cause permanent ... occipitocervical synostosis and unilateral hearing loss. Are there any ... postures? Yes. Abnormal head postures can usually be improved depending ...

  13. Urine - abnormal color

    MedlinePlus

    ... straw-yellow. Abnormally colored urine may be cloudy, dark, or blood-colored. Causes Abnormal urine color may ... red blood cells, or mucus in the urine. Dark brown but clear urine is a sign of ...

  14. Impact of a visual programming experience on the attitude toward programming of introductory undergraduate students

    NASA Astrophysics Data System (ADS)

    Godbole, Saurabh

    Traditionally, textual tools have been utilized to teach basic programming languages and paradigms. Research has shown that students tend to be visual learners. Using flowcharts, students can quickly understand the logic of their programs and visualize the flow of commands in the algorithm. Moreover, applying programming to physical systems through the use of a microcontroller to facilitate this type of learning can spark an interest in students to advance their programming knowledge to create novel applications. This study examined if freshmen college students' attitudes towards programming changed after completing a graphical programming lesson. Various attributes about students' attitudes were examined including confidence, interest, stereotypes, and their belief in the usefulness of acquiring programming skills. The study found that there were no statistically significant differences in attitudes either immediately following the session or after a period of four weeks.

  15. Visual Outcomes after Endoscopic Endonasal Approach for Craniopharyngioma: The Pittsburgh Experience.

    PubMed

    Stefko, S Tonya; Snyderman, Carl; Fernandez-Miranda, Juan; Tyler-Kabara, Elizabeth; Wang, Eric; Bodily, Lance; Bilonick, Richard A; Gardner, Paul A

    2016-08-01

    This series of patients has been published in the neurosurgical literature earlier this year, detailing multiple aspects of both the surgical technique and postoperative outcomes. Our aim in this series is not to revisit all the aspects of this publication, but rather to analyze more specifically the benefits of this procedure as it pertains to the preservation of neurological structures of vision-specifically the optic chiasm-and provide a more detailed analysis of visual outcomes in these patients. PMID:27441158

  16. The Dynamics of Visual Experience, an EEG Study of Subjective Pattern Formation

    PubMed Central

    Elliott, Mark A.; Twomey, Deirdre; Glennon, Mark

    2012-01-01

    Background Since the origin of psychological science a number of studies have reported visual pattern formation in the absence of either physiological stimulation or direct visual-spatial references. Subjective patterns range from simple phosphenes to complex patterns but are highly specific and reported reliably across studies. Methodology/Principal Findings Using independent-component analysis (ICA) we report a reduction in amplitude variance consistent with subjective-pattern formation in ventral posterior areas of the electroencephalogram (EEG). The EEG exhibits significantly increased power at delta/theta and gamma-frequencies (point and circle patterns) or a series of high-frequency harmonics of a delta oscillation (spiral patterns). Conclusions/Significance Subjective-pattern formation may be described in a way entirely consistent with identical pattern formation in fluids or granular flows. In this manner, we propose subjective-pattern structure to be represented within a spatio-temporal lattice of harmonic oscillations which bind topographically organized visual-neuronal assemblies by virtue of low frequency modulation. PMID:22292053

  17. Decoding the future from past experience: learning shapes predictions in early visual cortex

    PubMed Central

    Luft, Caroline D. B.; Meeson, Alan; Welchman, Andrew E.

    2015-01-01

    Learning the structure of the environment is critical for interpreting the current scene and predicting upcoming events. However, the brain mechanisms that support our ability to translate knowledge about scene statistics to sensory predictions remain largely unknown. Here we provide evidence that learning of temporal regularities shapes representations in early visual cortex that relate to our ability to predict sensory events. We tested the participants' ability to predict the orientation of a test stimulus after exposure to sequences of leftward- or rightward-oriented gratings. Using fMRI decoding, we identified brain patterns related to the observers' visual predictions rather than stimulus-driven activity. Decoding of predicted orientations following structured sequences was enhanced after training, while decoding of cued orientations following exposure to random sequences did not change. These predictive representations appear to be driven by the same large-scale neural populations that encode actual stimulus orientation and to be specific to the learned sequence structure. Thus our findings provide evidence that learning temporal structures supports our ability to predict future events by reactivating selective sensory representations as early as in primary visual cortex. PMID:25744884

  18. Drosophila-inspired visual orientation model on the Eye-RIS platform: experiments on a roving robot

    NASA Astrophysics Data System (ADS)

    Arena, P.; De Fiore, S.; Patané, L.; Alba, L.; Strauss, R.

    2011-05-01

    Behavioral experiments on fruit flies had shown that they are attracted by near objects and they prefer front-to-back motion. In this paper a visual orientation model is implemented on the Eye-Ris vision system and tested using a roving platform. Robotic experiments are used to collect statistical data regarding the system behaviour: followed trajectories, dwelling time, distribution of gaze direction and others strictly resembling the biological experimental setup on the flies. The statistical analysis has been performed in different scenarios where the robot faces with different object distribution in the arena. The acquired data has been used to validate the proposed model making a comparison with the fruit fly experiments.

  19. Early visual experience shapes the representation of auditory space in the forebrain gaze fields of the barn owl.

    PubMed

    Miller, G L; Knudsen, E I

    1999-03-15

    Auditory spatial information is processed in parallel forebrain and midbrain pathways. Sensory experience early in life has been shown to exert a powerful influence on the representation of auditory space in the midbrain space-processing pathway. The goal of this study was to determine whether early experience also shapes the representation of auditory space in the forebrain. Owls were raised wearing prismatic spectacles that shifted the visual field in the horizontal plane. This manipulation altered the relationship between interaural time differences (ITDs), the principal cue used for azimuthal localization, and locations of auditory stimuli in the visual field. Extracellular recordings were used to characterize ITD tuning in the auditory archistriatum (AAr), a subdivision of the forebrain gaze fields, in normal and prism-reared owls. Prism rearing altered the representation of ITD in the AAr. In prism-reared owls, unit tuning for ITD was shifted in the adaptive direction, according to the direction of the optical displacement imposed by the spectacles. Changes in ITD tuning involved the acquisition of unit responses to adaptive ITD values and, to a lesser extent, the elimination of responses to nonadaptive (previously normal) ITD values. Shifts in ITD tuning in the AAr were similar to shifts in ITD tuning observed in the optic tectum of the same owls. This experience-based adjustment of binaural tuning in the AAr helps to maintain mutual registry between the forebrain and midbrain representations of auditory space and may help to ensure consistent behavioral responses to auditory stimuli. PMID:10066282

  20. 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. PMID:18053744

  1. Birds of a Feather Flock Together: Experience-Driven Formation of Visual Object Categories in Human Ventral Temporal Cortex

    PubMed Central

    van der Linden, Marieke; Murre, Jaap M. J.; van Turennout, Miranda

    2008-01-01

    The present functional magnetic resonance imaging study provides direct evidence on visual object-category formation in the human brain. Although brain imaging has demonstrated object-category specific representations in the occipitotemporal cortex, the crucial question of how the brain acquires this knowledge has remained unresolved. We designed a stimulus set consisting of six highly similar bird types that can hardly be distinguished without training. All bird types were morphed with one another to create different exemplars of each category. After visual training, fMRI showed that responses in the right fusiform gyrus were larger for bird types for which a discrete category-boundary was established as compared with not-trained bird types. Importantly, compared with not-trained bird types, right fusiform responses were smaller for visually similar birds to which subjects were exposed during training but for which no category-boundary was learned. These data provide evidence for experience-induced shaping of occipitotemporal responses that are involved in category learning in the human brain. PMID:19107187

  2. When imagining yourself in pain, visual perspective matters: the neural and behavioral correlates of simulated sensory experiences.

    PubMed

    Christian, Brittany M; Parkinson, Carolyn; Macrae, C Neil; Miles, Lynden K; Wheatley, Thalia

    2015-05-01

    Via mental simulation, imagined events faithfully reproduce the neural and behavioral activities that accompany their actual occurrence. However, little is known about how fundamental characteristics of mental imagery-notably perspectives of self-shape neurocognitive processes. To address this issue, we used fMRI to explore the impact that vantage point exerts on the neural and behavioral correlates of imaginary sensory experiences (i.e., pain). Participants imagined painful scenarios from three distinct visual perspectives: first-person self (1PS), third-person self (3PS), and third-person other (3PO). Corroborating increased ratings of pain and embodiment, 1PS (cf. 3PS) simulations elicited greater activity in the right anterior insula, a brain area that supports interoceptive and emotional awareness. Additionally, 1PS simulations evoked greater activity in brain areas associated with visual imagery and the sense of body ownership. Interestingly, no differences were observed between 3PS and 3PO imagery. Taken together, these findings reveal the neural and behavioral correlates of visual perspective during mental simulation. PMID:25390204

  3. Psychophysical experiments on visual performance with an ocular adaptive optics system - Oral Paper

    NASA Astrophysics Data System (ADS)

    Dalimier, E.; Dainty, J. C.; Barbur, J. L.

    2008-01-01

    An ocular adaptive optics system was used to investigate the effects of higher-order ocular aberrations on everyday functional vision. The system comprised a Shack-Hartmann wavefront sensor, a Badal optometer and cylindrical lenses to statically pre-correct refractive errors, and a 35 element bimorph mirror from AOptix to dynamically compensate for higher-order aberrations. Measurements of contrast acuity with and without correction of higher-order aberrations were performed in a large range of light levels and pupil sizes. The results showed that the visual benefit is limited at all light levels due to the combined effects of light level on pupil size and neural sensitivity.

  4. Mantid - Data Analysis and Visualization Package for Neutron Scattering and $\\mu SR$ Experiments

    SciTech Connect

    Arnold, Owen; Bilheux, Jean-Christophe; Borreguero Calvo, Jose M; Buts, Alex; Campbell, Stuart I; Doucet, Mathieu; Draper, Nicholas J; Ferraz Leal, Ricardo F; Gigg, Martyn; Lynch, Vickie E; Mikkelson, Dennis J; Mikkelson, Ruth L; Miller, Ross G; Perring, Toby G; Peterson, Peter F; Ren, Shelly; Reuter, Michael A; Savici, Andrei T; Taylor, Jonathan W; Taylor, Russell J; Zhou, Wenduo; Zikovsky, Janik L

    2014-11-01

    The Mantid framework is a software solution developed for the analysis and visualization of neutron scattering and muon spin measurements. The framework is jointly developed by a large team of software engineers and scientists at the ISIS Neutron and Muon Facility and the Oak Ridge National Laboratory. The objective of the development is to improve software quality, both in terms of performance and ease of use, for the the user community of large scale facilities. The functionality and novel design aspects of the framework are described.

  5. Behavioral evidence for inter-hemispheric cooperation during a lexical decision task: a divided visual field experiment

    PubMed Central

    Perrone-Bertolotti, Marcela; Lemonnier, Sophie; Baciu, Monica

    2013-01-01

    HIGHLIGHTS The redundant bilateral visual presentation of verbal stimuli decreases asymmetry and increases the cooperation between the two hemispheres.The increased cooperation between the hemispheres is related to semantic information during lexical processing.The inter-hemispheric interaction is represented by both inhibition and cooperation. This study explores inter-hemispheric interaction (IHI) during a lexical decision task by using a behavioral approach, the bilateral presentation of stimuli within a divided visual field experiment. Previous studies have shown that compared to unilateral presentation, the bilateral redundant (BR) presentation decreases the inter-hemispheric asymmetry and facilitates the cooperation between hemispheres. However, it is still poorly understood which type of information facilitates this cooperation. In the present study, verbal stimuli were presented unilaterally (left or right visual hemi-field successively) and bilaterally (left and right visual hemi-field simultaneously). Moreover, during the bilateral presentation of stimuli, we manipulated the relationship between target and distractors in order to specify the type of information which modulates the IHI. Thus, three types of information were manipulated: perceptual, semantic, and decisional, respectively named pre-lexical, lexical and post-lexical processing. Our results revealed left hemisphere (LH) lateralization during the lexical decision task. In terms of inter-hemisphere interaction, the perceptual and decision-making information increased the inter-hemispheric asymmetry, suggesting the inhibition of one hemisphere upon the other. In contrast, semantic information decreased the inter-hemispheric asymmetry, suggesting cooperation between the hemispheres. We discussed our results according to current models of IHI and concluded that cerebral hemispheres interact and communicate according to various excitatory and inhibitory mechanisms, all which depend on specific

  6. Real-time analysis, visualization, and steering of microtomography experiments at photon sources

    SciTech Connect

    von Laszeski, G.; Insley, J. A.; Foster, I.; Bresnahan, J.; Kesselman, C.; Su, M.; Thiebaux, M.; Rivers, M. L.; Wang, S.; Tieman, B., McNulty, I.

    2000-02-29

    A new generation of specialized scientific instruments called synchrotron light sources allow the imaging of materials at very fine scales. However, in contrast to a traditional microscope, interactive use has not previously been possible because of the large amounts of data generated and the considerable computation required translating this data into a useful image. The authors describe a new software architecture that uses high-speed networks and supercomputers to enable quasi-real-time and hence interactive analysis of synchrotron light source data. This architecture uses technologies provided by the Globus computational grid toolkit to allow dynamic creation of a reconstruction pipeline that transfers data from a synchrotron source beamline to a preprocessing station, next to a parallel reconstruction system, and then to multiple visualization stations. Collaborative analysis tools allow multiple users to control data visualization. As a result, local and remote scientists can see and discuss preliminary results just minutes after data collection starts. The implications for more efficient use of this scarce resource and for more effective science appear tremendous.

  7. Comparison between numerical simulation and visualization experiment on water behavior in single straight flow channel polymer electrolyte fuel cells

    NASA Astrophysics Data System (ADS)

    Masuda, Hiromitsu; Ito, Kohei; Oshima, Toshihiro; Sasaki, Kazunari

    A relationship between a flooding and a cell voltage drop for polymer electrolyte fuel cell was investigated experimentally and numerically. A visualization cell, which has single straight gas flow channel (GFC) and observation window, was fabricated to visualize the flooding in GFC. We ran the cell with changing operation condition, and measured the time evolution of cell voltage and took the images of cathode GFC. Considering the operation condition, we executed a developed numerical simulation, which is based on multiphase mixture model with a formulation on water transport through the surface of polymer electrolyte membrane and the interface of gas diffusion layer/GFC. As a result in experiment, we found that the cell voltage decreased with time and this decrease was accelerated by larger current and smaller air flow rate. Our simulation succeeded to demonstrate this trend of cell voltage. In experiment, we also found that the water flushing in GFC caused an immediate voltage change, resulting in voltage recovery or electricity generation stop. Although our simulation could not replicate this immediate voltage change, the supersaturated area obtained by our simulation well corresponded to fogging area appeared on the window surface in the GFC.

  8. Abnormal Saccadic Eye Movements in Autistic Children.

    ERIC Educational Resources Information Center

    Kemner, C.; Verbaten, M. N.; Cuperus, J. M.; Camfferman, G.; van Engeland, H.

    1998-01-01

    The saccadic eye movements, generated during a visual oddball task, were compared for 10 autistic children, 10 children with attention deficit hyperactivity disorder, 10 dyslexic children, and 10 typically developing children. Several abnormal patterns of saccades were found in the autistic group. (DB)

  9. Motion perception: a review of developmental changes and the role of early visual experience

    PubMed Central

    Hadad, Batsheva; Schwartz, Sivan; Maurer, Daphne; Lewis, Terri L.

    2015-01-01

    Significant controversies have arisen over the developmental trajectory for the perception of global motion. Studies diverge on the age at which it becomes adult-like, with estimates ranging from as young as 3 years to as old as 16. In this article, we review these apparently conflicting results and suggest a potentially unifying hypothesis that may also account for the contradictory literature in neurodevelopmental disorders, such as Autism Spectrum Disorder (ASD). We also discuss the extent to which patterned visual input during this period is necessary for the later development of motion perception. We conclude by addressing recent studies directly comparing different types of motion integration, both in typical and atypical development, and suggest areas ripe for future research. PMID:26441564

  10. Labyrinth seal leakage resistance and visualization experiments in a novel, variable-configuration facility

    NASA Astrophysics Data System (ADS)

    Rhode, D. L.; Broussard, D. H.; Veldanda, S. B.

    1993-04-01

    The present experimental investigation is concerned with measuring and understanding the variation of leakage resistance of stepped labyrinth seals over a wide range of geometries. Important details of the novel test facility design and operation are discussed. It was observed that several of the geometrical dimensions are often coupled in a complicated way, which produces a significant and unexpected variation in leakage resistance for a slight change in geometry. Both flow visualization and leakage resistance data were taken and analyzed in an integrated fashion. The result was an improved understanding of the mainstream path and turbulence resulting from the cavity geometry. Each of the three values of radial clearance considered here resulted in a generally different relationship between cavity configuration and leakage resistance.

  11. Visualization and experiment of tip vortex phenomenon in cooling fan using digital particle image velocimetry

    NASA Astrophysics Data System (ADS)

    Xie, Junlong; Wang, Xuejun; Wu, Guanghui; Wu, Keqi

    2004-11-01

    The Digital Particle Image Velocimetry (DPIV) is an efficient method for measuring the internal flow field of a low-speed cooling fan. This paper studied the velocity field by means of PIV technology for a leading edge swept axial-flow fan without casing, and the tip vortex phenomenon was observed. Time-averaged velocity measurements were taken near the pressure surface, the suction surface and the tip of blade, etc. Moreover, the flow characteristics were visualized using numerical techniques. Experimental results showed that this tip vortex existed at the leading edge of the blade. The generating, developing and dissipating evolvement process of the tip vortex from the blade leading edge to downstream were discussed in detail. In addition, by comparing DPIV results and numerical results, a good agreement between them indicated a possibility to predict flow field using CFD tools. The experimental data provided in this paper are reliable for improving the aerodynamic characteristics of the open axial fan.

  12. Motion perception: a review of developmental changes and the role of early visual experience.

    PubMed

    Hadad, Batsheva; Schwartz, Sivan; Maurer, Daphne; Lewis, Terri L

    2015-01-01

    Significant controversies have arisen over the developmental trajectory for the perception of global motion. Studies diverge on the age at which it becomes adult-like, with estimates ranging from as young as 3 years to as old as 16. In this article, we review these apparently conflicting results and suggest a potentially unifying hypothesis that may also account for the contradictory literature in neurodevelopmental disorders, such as Autism Spectrum Disorder (ASD). We also discuss the extent to which patterned visual input during this period is necessary for the later development of motion perception. We conclude by addressing recent studies directly comparing different types of motion integration, both in typical and atypical development, and suggest areas ripe for future research. PMID:26441564

  13. Perceptual assimilation of lexical tone: the roles of language experience and visual information.

    PubMed

    Reid, Amanda; Burnham, Denis; Kasisopa, Benjawan; Reilly, Ronan; Attina, Virginie; Rattanasone, Nan Xu; Best, Catherine T

    2015-02-01

    Using Best's (1995) perceptual assimilation model (PAM), we investigated auditory-visual (AV), auditory-only (AO), and visual-only (VO) perception of Thai tones. Mandarin and Cantonese (tone-language) speakers were asked to categorize Thai tones according to their own native tone categories, and Australian English (non-tone-language) speakers to categorize Thai tones into their native intonation categories-for instance, question or statement. As comparisons, Thai participants completed a straightforward identification task, and another Australian English group identified the Thai tones using simple symbols. All of the groups also completed an AX discrimination task. Both the Mandarin and Cantonese groups categorized AO and AV Thai falling tones as their native level tones, and Thai rising tones as their native rising tones, although the Mandarin participants found it easier to categorize Thai level tones than did the Cantonese participants. VO information led to very poor categorization for all groups, and AO and AV information also led to very poor categorizations for the English intonation categorization group. PAM's predictions regarding tone discriminability based on these category assimilation patterns were borne out for the Mandarin group's AO and AV discriminations, providing support for the applicability of the PAM to lexical tones. For the Cantonese group, however, PAM was unable to account for one specific discrimination pattern-namely, their relatively good performance on the Thai high-rising contrast in the auditory conditions-and no predictions could be derived for the English groups. A full account of tone assimilation will likely need to incorporate considerations of phonetic, and even acoustic, similarity and overlap between nonnative and native tone categories. PMID:25465395

  14. Art Experiences for Young Children with Severe Visual Imapairments: Report from the Field.

    ERIC Educational Resources Information Center

    Swenson, Anna M.

    1987-01-01

    Ten guidelines are offered for providing art experiences for blind young children include adding sound, smell, or taste whenever possible. Suggested activities include making styrofoam-toothpick sculptures, box sculptures, tape and feather collages, torn paper collages, and fingerpaintings. (DB)

  15. The usefulness of computed tomography in detecting asbestos-related pleural abnormalities in people who had indeterminate chest radiographs: the Libby, MT, experience.

    PubMed

    Muravov, Oleg I; Kaye, Wendy E; Lewin, Michael; Berkowitz, Zahava; Lybarger, Jeffrey A; Campolucci, Sharon S; Parker, John E

    2005-01-01

    This epidemiological study was conducted to determine whether high-resolution computed tomography (HRCT) is useful to screen for pulmonary abnormalities in people exposed to vermiculite containing asbestos. During June-September 2001, we evaluated HRCT of 353 people in Libby, MT, who had been exposed to asbestiform minerals associated with vermiculite. Of these, 334 participants of the summer 2000 medical testing program underwent HRCT of the chest at St. John's Lutheran Hospital and 19 eligible people who recently had undergone an HRCT scan at the same facility and under the same testing protocol allowed the study reviewers to use that scan. All 353 study participants were former vermiculite mine/mill workers (n = 55), their household contacts (n = 99), and people exposed to vermiculite through recreational or other activities (n = 199). Participants' 2000 medical testing results indicated only one of the three B-reader chest radiograph reviewers had reported a pleural abnormality (indeterminate chest radiograph). Three expert computer tomography (CT) scan evaluators reviewed the HRCT scans and identified pleural abnormalities in 98 (27.8%) of the 353 participants whose previous chest radiographs were classified indeterminate. Of these 98 people, 69 (70.4%) were either former vermiculite mine/mill workers or household contacts, and 40 (40.8%) showed pleural calcification on HRCT. Thirty out of the 40 people with pleural calcification reported having no occupational exposure to either Libby vermiculite or asbestos. Our findings indicate that low-dose HRCT can be considered for screening certain former vermiculite mine/mill workers and their household contacts who have indeterminate chest radiographs and may be useful for diagnosing a suspicious finding on a chest radiograph, particularly in a high-risk person. PMID:15881982

  16. Tooth - abnormal shape

    MedlinePlus

    Hutchinson incisors; Abnormal tooth shape; Peg teeth; Mulberry teeth; Conical teeth ... The appearance of normal teeth varies, especially the molars. ... conditions. Specific diseases can affect tooth shape, tooth ...

  17. Tooth - abnormal shape

    MedlinePlus

    Hutchinson incisors; Abnormal tooth shape; Peg teeth; Mulberry teeth; Conical teeth ... from many different conditions. Specific diseases can affect tooth shape, tooth color, time of appearance, or absence ...

  18. Visual Earth observation performance in the space environment. Human performance measurement 4: Flight experiments

    NASA Technical Reports Server (NTRS)

    Huth, John F.; Whiteley, James D.; Hawker, John E.

    1993-01-01

    A wide variety of secondary payloads have flown on the Space Transportation System (STS) since its first flight in the 1980's. These experiments have typically addressed specific issues unique to the zero-gravity environment. Additionally, the experiments use the experience and skills of the mission and payload specialist crew members to facilitate data collection and ensure successful completion. This paper presents the results of the Terra Scout experiment, which flew aboard STS-44 in November 1991. This unique Earth Observation experiment specifically required a career imagery analyst to operate the Spaceborne Direct-View Optical System (SpaDVOS), a folded optical path telescope system designed to mount inside the shuttle on the overhead aft flight deck windows. Binoculars and a small telescope were used as backup optics. Using his imagery background, coupled with extensive target and equipment training, the payload specialist was tasked with documenting the following: (1) the utility of the equipment; (2) his ability to acquire and track ground targets; (3) the level of detail he could discern; (4) the atmospheric conditions; and (5) other in-situ elements which contributed to or detracted from his ability to analyze targets. Special emphasis was placed on the utility of a manned platform for research and development of future spaceborne sensors. The results and lessons learned from Terra Scout will be addressed including human performance and equipment design issues.

  19. Collaborative WorkBench (cwb): Enabling Experiment Execution, Analysis and Visualization with Increased Scientific Productivity

    NASA Astrophysics Data System (ADS)

    Maskey, Manil; Ramachandran, Rahul; Kuo, Kwo-Sen

    2015-04-01

    The Collaborative WorkBench (CWB) has been successfully developed to support collaborative science algorithm development. It incorporates many features that enable and enhance science collaboration, including the support for both asynchronous and synchronous modes of interactions in collaborations. With the former, members in a team can share a full range of research artifacts, e.g. data, code, visualizations, and even virtual machine images. With the latter, they can engage in dynamic interactions such as notification, instant messaging, file exchange, and, most notably, collaborative programming. CWB also implements behind-the-scene provenance capture as well as version control to relieve scientists of these chores. Furthermore, it has achieved a seamless integration between researchers' local compute environments and those of the Cloud. CWB has also been successfully extended to support instrument verification and validation. Adopted by almost every researcher, the current practice of downloading data to local compute resources for analysis results in much duplication and inefficiency. CWB leverages Cloud infrastructure to provide a central location for data used by an entire science team, thereby eliminating much of this duplication and waste. Furthermore, use of CWB in concert with this same Cloud infrastructure enables co-located analysis with data where opportunities of data-parallelism can be better exploited, thereby further improving efficiency. With its collaboration-enabling features apposite to steps throughout the scientific process, we expect CWB to fundamentally transform research collaboration and realize maximum science productivity.

  20. Recognition of simple visual images using a sparse distributed memory: Some implementations and experiments

    NASA Technical Reports Server (NTRS)

    Jaeckel, Louis A.

    1990-01-01

    Previously, a method was described of representing a class of simple visual images so that they could be used with a Sparse Distributed Memory (SDM). Herein, two possible implementations are described of a SDM, for which these images, suitably encoded, will serve both as addresses to the memory and as data to be stored in the memory. A key feature of both implementations is that a pattern that is represented as an unordered set with a variable number of members can be used as an address to the memory. In the 1st model, an image is encoded as a 9072 bit string to be used as a read or write address; the bit string may also be used as data to be stored in the memory. Another representation, in which an image is encoded as a 256 bit string, may be used with either model as data to be stored in the memory, but not as an address. In the 2nd model, an image is not represented as a vector of fixed length to be used as an address. Instead, a rule is given for determining which memory locations are to be activated in response to an encoded image. This activation rule treats the pieces of an image as an unordered set. With this model, the memory can be simulated, based on a method of computing the approximate result of a read operation.

  1. A technique for preparing in vitro slices of cat's visual cortex for electrophysiological experiments.

    PubMed

    Kato, H; Ogawa, T

    1981-06-01

    A technique for the preparation and in vitro maintenance of slices of neocortex from cats anesthetized with Nembutal has been described in detail. The visual cortex (posterior lateral gyrus) was cut in slices in situ using a knife consisting of two razor blades with separation of 0.7--1.0 mm. An artificially-defined medium was sprayed abundantly over the brain throughout the slicing procedures. Slices thus obtained were immediately placed between nylon meshes and incubated in a well-oxygenated medium. For recording, one of the slices was transferred to an experimental chamber in which a medium was bubbled and circulated with a gas mixture (5% CO2 in O2) introduced through a glass filter fitted at the bottom. Slices thus treated gave large evoked potentials in response to stimulation of the white matter and high-frequency injury discharges as a macroelectrode was inserted into the tissue. They also allowed stable and high-quality intracellular recordings from single neurons. PMID:7253698

  2. Visual laser ablation of prostate (VLAP) for patients with retention of urine: personal experience

    NASA Astrophysics Data System (ADS)

    Bhatta, Krishna M.

    1994-05-01

    A total of 21 consecutive patients with retention of urine underwent visual laser ablation of prostate. Twelve of these had spinal anesthesia, eight had local anesthesia and one had general anesthesia. Seventeen had acute retention; 13 from BPH, 1 due to carcinoma of prostate and three were due to Bladder Neck Stenosis (BNS). Four had chronic retention; three due to BPH and one due to BNS. A Nd:YAG/KTP laser was used and the laser was delivered via Angle Delivery Device. All 13 patients in acute retention due to BPH became catheter free after a mean catheter time of 8 days (range 1 - 22 days), the three patients with acute retention due to BNS were catheter free the next day after the laser incision of the BNS and the patient with acute retention from carcinoma of prostate required a TURP after 45 days of initial laser irradiation. Of the four patients with chronic retention, three with BPH required a TURP procedure after waiting over a month. The patient with chronic retention with BNS was catheter free after 7 days of his laser procedure. We conclude that laser prostatectomy using a side firing laser probe is effective in patients with acute retention but did not work well in our hands for chronic retention patients.

  3. Understanding Student Experiences: A Case Study in Scientific Visualization and Civics and Economics

    ERIC Educational Resources Information Center

    Jessee, Emily George

    2012-01-01

    This research study provides the finding of a qualitative case study in Technology, Engineering, and Design Education as well as Social Studies Education. The purpose of this study was to describe the role of graphics within a social studies lesson by examining a student's experience when a new lesson is implemented in class. The participants…

  4. FLOW VISUALIZATION EXPERIMENTS ON STABLY STRATIFIED FLOW OVER RIDGES AND VALLEYS

    EPA Science Inventory

    The objective of the experiments was to define the flow over a simple cosine-shaped ridge and within a valley formed by a pair of such ridges when there is a stable ambient flow normal to the ridge. Three experimental parameters were varied during the study: the Froude number, th...

  5. Visual Data Collection Methods for Research on the Affective Dimensions of Children's Personal Experiences of PE

    ERIC Educational Resources Information Center

    Georgakis, Steve; Light, Richard

    2009-01-01

    The rapid growth of research on Teaching Games for Understanding (TGfU) over the past decade has paid little attention to research methodology. This paper redresses this lack of attention to research methods and reports on a study conducted on children's personal experiences of Game Sense. The study focuses on the use of year six students'…

  6. Including Visually Impaired Students in Physical Education Lessons: A Case Study of Teacher and Pupil Experiences

    ERIC Educational Resources Information Center

    Herold, Frank; Dandolo, Jack

    2009-01-01

    Following recent education policy and curriculum changes in England, the notion of inclusion of children with special educational needs in physical education has increasingly become a topic of research interest and concern. It was the aim of this study to explore personal experiences and perspectives of inclusion in physical education. To this end…

  7. Hemispheric Predominance Assessment of Phonology and Semantics: A Divided Visual Field Experiment

    ERIC Educational Resources Information Center

    Cousin, Emilie; Peyrin, Carole; Baciu, Monica

    2006-01-01

    The aim of the present behavioural experiment was to evaluate the most lateralized among two phonological (phoneme vs. rhyme detection) and the most lateralized among two semantic ("living" vs. "edible" categorization) tasks, within the dominant hemisphere for language. The reason of addressing this question was a practical one: to evaluate the…

  8. Oscillating Droplets and Incompressible Liquids: Slow-Motion Visualization of Experiments with Fluids

    ERIC Educational Resources Information Center

    Vollmer, Michael; Mollmann, Klaus-Peter

    2012-01-01

    We present fascinating simple demonstration experiments recorded with high-speed cameras in the field of fluid dynamics. Examples include oscillations of falling droplets, effects happening upon impact of a liquid droplet into a liquid, the disintegration of extremely large droplets in free fall and the consequences of incompressibility. (Contains…

  9. Structurally abnormal human autosomes

    SciTech Connect

    1993-12-31

    Chapter 25, discusses structurally abnormal human autosomes. This discussion includes: structurally abnormal chromosomes, chromosomal polymorphisms, pericentric inversions, paracentric inversions, deletions or partial monosomies, cri du chat (cat cry) syndrome, ring chromosomes, insertions, duplication or pure partial trisomy and mosaicism. 71 refs., 8 figs.

  10. Early Experience with Hyaluronic Acid Instillation to Assist with Visual Internal Urethrotomy for Urethral Stricture

    PubMed Central

    Kim, Hak Min; Kang, Dong Il; Shim, Bong Suk

    2010-01-01

    Purpose The clinical usefulness of hyaluronic acid (HA) instillation during visual internal urethrotomy (VIU) for decreasing the incidence of recurrent urethral stricture was assessed. Materials and Methods Twenty-eight patients were treated by VIU with HA instillation between May 2007 and June 2009. After insertion of a Foley catheter following urethrotomy, HA was instilled via an 18-gauge tube catheter between the urethral lumen and Foley catheter. Seventeen cases were analyzed retrospectively 12 months postoperatively. We evaluated the success rate of this procedure by comparing retrograde urethrography (RGU) results, maximum flow rates, and postvoid residual urine volumes preoperatively and 3 and 12 months postoperatively. Success was defined as either a maximum flow rate of at least 15 ml/s or no visible urethral stricture on RGU at 12 months postoperatively. Results Total success rates were 76.5% (13/17) and 52.9% (9/17) at 3 and 12 months postoperatively, respectively. By etiology, success rates at 3 and 12 months postoperatively, respectively, were 66.7% and 33.3% for inflammation, 66.7% and 50.0% for trauma, and 83.3% and 66.7% for unknown causes. Success rates were 63.6% for strictures less than 10 mm in length and 33.3% for strictures of 10 mm or more in length at 12 months postoperatively. Success rates were 61.5% for single strictures and 25% for multiple strictures at 12 months postoperatively. Conclusions The success rate of VIU with HA instillation was not better than that observed in the literature for conventional VIU. PMID:21221206

  11. Ground-based PIV and numerical flow visualization results from the Surface Tension Driven Convection Experiment

    NASA Technical Reports Server (NTRS)

    Pline, Alexander D.; Werner, Mark P.; Hsieh, Kwang-Chung

    1991-01-01

    The Surface Tension Driven Convection Experiment (STDCE) is a Space Transportation System flight experiment to study both transient and steady thermocapillary fluid flows aboard the United States Microgravity Laboratory-1 (USML-1) Spacelab mission planned for June, 1992. One of the components of data collected during the experiment is a video record of the flow field. This qualitative data is then quantified using an all electric, two dimensional Particle Image Velocimetry (PIV) technique called Particle Displacement Tracking (PDT), which uses a simple space domain particle tracking algorithm. Results using the ground based STDCE hardware, with a radiant flux heating mode, and the PDT system are compared to numerical solutions obtained by solving the axisymmetric Navier Stokes equations with a deformable free surface. The PDT technique is successful in producing a velocity vector field and corresponding stream function from the raw video data which satisfactorily represents the physical flow. A numerical program is used to compute the velocity field and corresponding stream function under identical conditions. Both the PDT system and numerical results were compared to a streak photograph, used as a benchmark, with good correlation.

  12. Ground-based PIV and numerical flow visualization results from the surface tension driven convection experiment

    NASA Technical Reports Server (NTRS)

    Pline, Alexander D.; Wernet, Mark P.; Hsieh, Kwang-Chung

    1991-01-01

    The Surface Tension Driven Convection Experiment (STDCE) is a Space Transportation System flight experiment to study both transient and steady thermocapillary fluid flows aboard the United States Microgravity Laboratory-1 (USML-1) Spacelab mission planned for June, 1992. One of the components of data collected during the experiment is a video record of the flow field. This qualitative data is then quantified using an all electric, two dimensional Particle Image Velocimetry (PIV) technique called Particle Displacement Tracking (PDT), which uses a simple space domain particle tracking algorithm. Results using the ground based STDCE hardware, with a radiant flux heating mode, and the PDT system are compared to numerical solutions obtained by solving the axisymmetric Navier Stokes equations with a deformable free surface. The PDT technique is successful in producing a velocity vector field and corresponding stream function from the raw video data which satisfactorily represents the physical flow. A numerical program is used to compute the velocity field and corresponding stream function under identical conditions. Both the PDT system and numerical results were compared to a streak photograph, used as a benchmark, with good correlation.

  13. Visualization of micro-scale phase displacement processes in retention and outflow experiments: Non-uniqueness of unsaturated flow properties

    SciTech Connect

    MORTENSEN,ANNETTE P.; GLASS JR.,ROBERT J.; HOLLENBECK,KARL; JENSEN,KARSTEN H.

    2000-03-09

    Methods to determine unsaturated hydraulic properties can exhibit random and non-unique behavior. The authors assess the causes for these behaviors by visualizing micro-scale phase displacement processes during equilibrium retention and transient outflow experiments. They observe that the drainage process is composed of a fast fingering followed by a slower backfilling. The influence of each these processes is controlled by the size and the speed of the applied boundary step, the initial saturation and its structure and by small-scale heterogeneities. Because the mixture of these micro-scale processes yields macro-scale effective behavior, measured unsaturated flow properties are also a function of these controls. These results suggest limitations on the current definitions and uniqueness of unsaturated hydraulic properties.

  14. Social responses without early experience: Australian brush-turkey chicks use specific visual cues to aggregate with conspecifics.

    PubMed

    Göth, Ann; Evans, Christopher S

    2004-06-01

    Almost all birds depend upon early experience with adults and siblings to learn recognition cues. Megapodes, such as the Australian brush-turkey (Alectura lathami), have evolved a very different life history. Eggs are incubated in mounds of decaying organic material. Chicks hatch asynchronously and receive no parental care, so imprinting cannot occur. Nevertheless, chicks subsequently form groups with similar-aged conspecifics. We explored the perceptual basis of this aggregation response, focussing on likely visual cues, such as pecking movements and body colour. Experiments were conducted under naturalistic conditions in a large aviary, using realistic robot models and colour filters. The robots successfully evoked a range of social responses resembling those of a live companion. Aggregation depended upon both behaviour and morphology. Simultaneous choice tests revealed that brush-turkey chicks preferred a pecking robot over either a static model or a scanning robot, suggesting that responsiveness depends upon particular movement patterns. In addition, chicks were sensitive to changes in appearance but only those that affected radiance at short wavelengths. The mechanism underlying social aggregation after hatching hence involves relatively specific cues. This perceptual bias seems to be largely experience independent and may exploit attributes to which potential predators are insensitive. PMID:15159424

  15. Investigation of NAA and NAAG dynamics underlying visual stimulation using MEGA-PRESS in a functional MRS experiment.

    PubMed

    Landim, Ricardo C G; Edden, Richard A E; Foerster, Bernd; Li, Li Min; Covolan, Roberto J M; Castellano, Gabriela

    2016-04-01

    N-acetyl-aspartate (NAA) is responsible for the majority of the most prominent peak in (1)H-MR spectra, and has been used as diagnostic marker for several pathologies. However, ~10% of this peak can be attributed to N-acetyl-aspartyl-glutamate (NAAG), a neuropeptide whose release may be triggered by intense neuronal activation. Separate measurement of NAA and NAAG using MRS is difficult due to large superposition of their spectra. Specifically, in functional MRS (fMRS) experiments, most work has evaluated the sum NAA+NAAG, which does not appear to change during experiments. The aim of this work was to design and perform an fMRS experiment using visual stimulation and a spectral editing sequence, MEGA-PRESS, to further evaluate the individual dynamics of NAA and NAAG during brain activation. The functional paradigm used consisted of three blocks, starting with a rest (baseline) block of 320 s, followed by a stimulus block (640 s) and a rest block (640 s). Twenty healthy subjects participated in this study. On average, subjects followed a pattern of NAA decrease and NAAG increase during stimulation, with a tendency to return to basal levels at the end of the paradigm, with a peak NAA decrease of -(21±19)% and a peak NAAG increase of (64±62)% (Wilcoxon test, p<0.05). These results may relate to: 1) the only known NAAG synthesis pathway is from NAA and glutamate; 2) a relationship between NAAG and the BOLD response. PMID:26656908

  16. Fluctuations in Neuronal Synchronization in Brain Activity Correlate with the Subjective Experience of Visual Recognition

    PubMed Central

    Dominguez, Luis Garcia; Erra, Ramon Guevara

    2007-01-01

    The scientific study of subjective experience is a current major research area in the neurosciences. Coordination patterns of brain activity are being studied to address the question of how brain function relates to behaviour, and particularly methods to estimate neuronal synchronization can unravel the spatio-temporal dynamics of the transient formation of neuronal assemblies. We report here a biophysical correlate of subjective experience. Subjects visualised figures with different levels of noise, while their brain activity was recorded using magnetoencephalography (MEG), and reported the moment in time (corresponding to a noise level) of figure recognition, which varied between individuals, as well as the moment when they saw the figure more clearly, which was mostly common among the participants (thus less subjective). This latter moment is considered to represent psychophysical stochastic resonance (PSR). Fluctuations in neuronal synchronization, quantified using a diffusion coefficient, were lower in occipital cortex when subjects recognised the figure, for a certain noise level, but did not correlate with the moment of PSR. A different pattern was observed in frontal cortex, where lower values of the diffusion coefficient in neuronal synchronization was maintained from the moment of recognition to the moment of PSR. No specific pattern was found analysing signals from temporal or parietal cortical areas. These observations provide support for distinct synchronization patterns in different cortical areas, and represent another demonstration that the subjective, first-person perspective is accessible to scientific methods. PMID:19669552

  17. 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. PMID:23372547

  18. OH PLIF Visualization of the UVa Supersonic Combustion Experiment: Configuration A

    NASA Technical Reports Server (NTRS)

    Johansen, Craig T.; McRae, Colin D.; Danehy, Paul M.; Gallo, Emanuela C. A.; Cantu, Luca M. L.; Magnotti, Gaetano; Cutler, Andrew D.; Rockwell, Robert D., Jr.; Goyne, Chris P.; McDaniel, James C.

    2013-01-01

    Hydroxyl radical (OH) planar laser-induced fluorescence (PLIF) measurements were performed in the University of Virginia supersonic combustion experiment. The test section was set up in configuration A, which includes a Mach 2 nozzle, combustor, and extender section. Hydrogen fuel was injected through an unswept compression ramp at two different equivalence ratios. Through the translation of the optical system and the use of two separate camera views, the entire optically accessible range of the combustor was imaged. Single-shot, average, and standard deviation images of the OH PLIF signal are presented at several streamwise locations. The results show the development of a highly turbulent flame structure and provide an experimental database to be used for numerical model assessment.

  19. OH PLIF Visualization of the UVa Supersonic Combustion Experiment: Configuration A

    NASA Technical Reports Server (NTRS)

    Johansen, Craig T.; McRae, Colin D.; Danehy, Paul M.; Gallo, Emanuela; Cantu, Luca Maria Luigi; Magnotti, Gaetano; Cutler, Andrew D.; Rockwell, Robert D.; Goyne, Christopher P.; McDaniel, James C.

    2012-01-01

    Hydroxyl radical (OH) planar laser-induced fluorescence (PLIF) measurements were performed in the University of Virginia s dual-mode scramjet experiment. The test section was set up in configuration A, which includes a Mach 2 nozzle, combustor, and extender section. Hydrogen fuel was injected through an unswept compression ramp at two different equivalence ratios. Through the translation of the optical system and the use of two separate camera views, the entire optical range of the combustor was accessed. Single-shot, average, and standard deviation images of the OH PLIF signal are presented at several streamwise locations. The results show the development of a highly turbulent flame structure and provide an experimental database to be used for numerical model assessment.

  20. Abnormal cubic-tetragonal phase transition of barium strontium titanate nanoparticles studied by in situ Raman spectroscopy and transmission electron microscopy heating experiments

    SciTech Connect

    Zhang, Yin; Chen, Chen; Gao, Ran; Xia, Feng; Li, YueSheng; Che, Renchao

    2015-11-02

    Phase stability of the ferroelectric materials at high temperature is extremely important to their device performance. Ba{sub x}Sr{sub 1−x}TiO{sub 3} (BST) nanoparticles with different Sr contents (x = 1, 0.91, 0.65, 0.4, and 0) are prepared by a facile hydrothermal method. Using Raman spectroscopy and transmission electron microscopy (TEM) analyses under in situ heating conditions (up to 300 °C), the phase transitions of BST nanoparticles between 25 °C and 280 °C are comprehensively investigated. The original Curie temperature of BST nanoparticles decreases abruptly with the increase in Sr content, which is more obvious than in the bulk or film material. Besides, an abnormal phase transition from cubic to tetragonal structure is observed from BST nanoparticles and the transition temperature rises along with the increase in Sr content. Direct TEM evidences including a slight lattice distortion have been provided. Differently, BaTiO{sub 3} nanoparticles remained in the tetragonal phase during the above temperature ranges.

  1. OH PLIF Visualization of the UVa Supersonic Combustion Experiment: Configuration C

    NASA Technical Reports Server (NTRS)

    McRae, Colin D.; Johansen, Craig T.; Danehy, Paul M.; Gallo, Emanuela C. A.; Cantu, Luca M. L.; Magnotti, Gaetano; Cutler, Andrew D.; Rockwell, Robert D., Jr.; Goyne, Christopher P.; McDnaiel, James C.

    2013-01-01

    Non-intrusive hydroxyl radical (OH) planar laser-induced fluorescence (PLIF) measurements were obtained in configuration C of the University of Virginia supersonic combustion experiment. The combustion of hydrogen fuel injected through an unswept compression ramp into a supersonic cross-flow was imaged over a range of streamwise positions. Images were corrected for optical distortion, variations in the laser sheet profile, and different camera views. Results indicate an effect of fuel equivalence ratio on combustion zone shape and local turbulence length scale. The streamwise location of the reaction zone relative to the fuel injector was also found to be sensitive to the fuel equivalence ratio. The flow boundary conditions in the combustor section, which are sensitive to the fuel flow rate, are believed to have caused this effect. A combination of laser absorption and radiative trapping effects are proposed to have caused asymmetry observed in the images. The results complement previously published OH PLIF data obtained for configuration A along with other non-intrusive measurements to form a database for computational fluid dynamics (CFD) model validation.

  2. "Jeopardy" in Abnormal Psychology.

    ERIC Educational Resources Information Center

    Keutzer, Carolin S.

    1993-01-01

    Describes the use of the board game, Jeopardy, in a college level abnormal psychology course. Finds increased student interaction and improved application of information. Reports generally favorable student evaluation of the technique. (CFR)

  3. Abnormal Uterine Bleeding

    MedlinePlus

    ... Abnormal uterine bleeding is any bleeding from the uterus (through your vagina) other than your normal monthly ... or fibroids (small and large growths) in the uterus can also cause bleeding. Rarely, a thyroid problem, ...

  4. Abnormal Uterine Bleeding FAQ

    MedlinePlus

    ... as cancer of the uterus, cervix, or vagina • Polycystic ovary syndrome How is abnormal bleeding diagnosed? Your health care ... before the fetus can survive outside the uterus. Polycystic Ovary Syndrome: A condition characterized by two of the following ...

  5. Spectrum of visual disorders in children with cerebral visual impairment.

    PubMed

    Fazzi, Elisa; Signorini, Sabrina Giovanna; Bova, Stefania Maria; La Piana, Roberta; Ondei, Paola; Bertone, Chiara; Misefari, Walter; Bianchi, Paolo Emilio

    2007-03-01

    Cerebral visual impairment is a visual function deficit caused by damage to the retrogeniculate visual pathways in the absence of any major ocular disease. It is the main visual deficit in children in the developed world. Preperinatal hypoxic-ischemic damage is the most frequent cause of cerebral visual impairment, but the etiology is variable. The authors set out to evaluate the presence of visual disorders not attributable to any major ocular pathology in a sample of children with central nervous system disease and to describe the clinical picture of cerebral visual impairment in this cohort. One hundred twenty-one patients with central nervous system damage and visual impairment underwent a protocol developed at the authors' center that included neurologic, neurophthalmologic, and neuroradiologic assessments (brain magnetic resonance imaging). Reduced visual acuity was found in 105 of 121 patients, reduced contrast sensitivity in 58, abnormal optokinetic nystagmus in 88, and visual field deficit in 7. Fixation was altered in 58 patients, smooth pursuit in 95, and saccadic movements in 41. Strabismus was present in 88 patients, and abnormal ocular movements were found in 43 patients. Of the 27 patients in whom they could be assessed, visual-perceptual abilities were found to be impaired in 24. Fundus oculi abnormalities and refractive errors were frequently associated findings. This study confirms that the clinical expression of cerebral visual impairment can be variable and that, in addition to already well-documented symptoms (such as reduced visual acuity, visual field deficits, reduced contrast sensitivity), the clinical picture can also be characterized by oculomotor or visual-cognitive disorders. Cerebral visual impairment is often associated with ophthalmologic abnormalities, and these should be carefully sought. Early and careful assessment, taking into account both the neurophthalmologic and the ophthalmologic aspects, is essential for a correct

  6. Chromosomal Abnormalities and Schizophrenia

    PubMed Central

    BASSETT, ANNE S.; CHOW, EVA W.C.; WEKSBERG, ROSANNA

    2011-01-01

    Schizophrenia is a common and serious psychiatric illness with strong evidence for genetic causation, but no specific loci yet identified. Chromosomal abnormalities associated with schizophrenia may help to understand the genetic complexity of the illness. This paper reviews the evidence for associations between chromosomal abnormalities and schizophrenia and related disorders. The results indicate that 22q11.2 microdeletions detected by fluorescence in-situ hybridization (FISH) are significantly associated with schizophrenia. Sex chromosome abnormalities seem to be increased in schizophrenia but insufficient data are available to indicate whether schizophrenia or related disorders are increased in patients with sex chromosome aneuploidies. Other reports of chromosomal abnormalities associated with schizophrenia have the potential to be important adjuncts to linkage studies in gene localization. Advances in molecular cytogenetic techniques (i.e., FISH) have produced significant increases in rates of identified abnormalities in schizophrenia, particularly in patients with very early age at onset, learning difficulties or mental retardation, or dysmorphic features. The results emphasize the importance of considering behavioral phenotypes, including adult onset psychiatric illnesses, in genetic syndromes and the need for clinicians to actively consider identifying chromosomal abnormalities and genetic syndromes in selected psychiatric patients. PMID:10813803

  7. 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

  8. Sleep physiology, abnormal States, and therapeutic interventions.

    PubMed

    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

  9. 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

  10. Detection experiments with humans implicate visual predation as a driver of colour polymorphism dynamics in pygmy grasshoppers

    PubMed Central

    2013-01-01

    Background Animal colour patterns offer good model systems for studies of biodiversity and evolution of local adaptations. An increasingly popular approach to study the role of selection for camouflage for evolutionary trajectories of animal colour patterns is to present images of prey on paper or computer screens to human ‘predators’. Yet, few attempts have been made to confirm that rates of detection by humans can predict patterns of selection and evolutionary modifications of prey colour patterns in nature. In this study, we first analyzed encounters between human ‘predators’ and images of natural black, grey and striped colour morphs of the polymorphic Tetrix subulata pygmy grasshoppers presented on background images of unburnt, intermediate or completely burnt natural habitats. Next, we compared detection rates with estimates of capture probabilities and survival of free-ranging grasshoppers, and with estimates of relative morph frequencies in natural populations. Results The proportion of grasshoppers that were detected and time to detection depended on both the colour pattern of the prey and on the type of visual background. Grasshoppers were detected more often and faster on unburnt backgrounds than on 50% and 100% burnt backgrounds. Striped prey were detected less often than grey or black prey on unburnt backgrounds; grey prey were detected more often than black or striped prey on 50% burnt backgrounds; and black prey were detected less often than grey prey on 100% burnt backgrounds. Rates of detection mirrored previously reported rates of capture by humans of free-ranging grasshoppers, as well as morph specific survival in the wild. Rates of detection were also correlated with frequencies of striped, black and grey morphs in samples of T. subulata from natural populations that occupied the three habitat types used for the detection experiment. Conclusions Our findings demonstrate that crypsis is background-dependent, and implicate visual predation

  11. M.I.T./Canadian vestibular experiments on the Spacelab-1 mission: 2. Visual vestibular tilt interaction in weightlessness

    NASA Technical Reports Server (NTRS)

    Young, L. R.; Shelhamer, M.; Modestino, S.

    1986-01-01

    Adaptation to weightlessness includes the substitution of other sensory signals for the no longer appropriate graviceptor information concerning static spatial orientation. Visual-vestibular interaction producing roll circularvection was studied in weightlessness to assess the influence of otolith cues on spatial orientation. Preliminary results from four subjects tested on Spacelab-1 indicate that visual orientation effects were stronger in weightlessness than pre-flight. The rod and frame test of visual field dependence showed a weak post-flight increase in visual influence. Localized tactile cues applied to the feet in space reduced subjective vection strength.

  12. Spatially resolved, diffuse reflectance imaging for subsurface pattern visualization toward development of a lensless imaging platform: phantom experiments

    NASA Astrophysics Data System (ADS)

    Schelkanova, Irina; Pandya, Aditya; Saiko, Guennadi; Nacy, Lidia; Babar, Hannan; Shah, Duoaud; Lilge, Lothar; Douplik, Alexandre

    2016-01-01

    A portable, spatially resolved, diffuse reflectance lensless imaging technique based on the charge-coupled device or complementary metal-oxide semiconductor sensor directly coupled to the fiber optic bundle is proposed for visualization of subsurface structures such as superficial microvasculature in the epithelium. We discuss an experimental method for emulating a lensless imaging setup via raster scanning a single fiber-optic cable over a microfluidic phantom containing periodic hemoglobin absorption contrast. To evaluate the ability of the technique to recover information about the subsurface linear structures, scattering layers formed of the Sylgard® 184 Silicone Elastomer and titanium dioxide were placed atop the microfluidic phantom. Thickness of the layers ranged from 0.2 to 0.7 mm, and the values of the reduced scattering coefficient (μs‧) were between 0.85 and 4.25 mm-1. The results demonstrate that fiber-optic, lensless platform can be used for two-dimensional imaging of absorbing inclusions in diffuse reflectance mode. In these experiments, it was shown that diffuse reflectance imaging can provide sufficient spatial sampling of the phantom for differentiation of 30 μm structural features of the embedded absorbing pattern inside the scattering media.

  13. Preliminary experiments on surface flow visualization in the cryogenic wind tunnel by use of condensing or freezing gases

    NASA Technical Reports Server (NTRS)

    Goodyer, M. J.

    1988-01-01

    Cryogenic wind tunnel users must have available surface flow visualization techniques to satisfy a variety of needs. While the ideal from an aerodynamic stand would be non-intrusive, until an economical technique is developed there will be occasions when the user will be prepared to resort to an intrusive method. One such method is proposed, followed by preliminary evaluation experiments carried out in environments representative of the cryogenic nitrogen tunnel. The technique uses substances which are gases at normal temperature and pressure but liquid or solid at cryogenic temperatures. These are deposited on the model in localized regions, the patterns of the deposits and their subsequent melting or evaporation revealing details of the surface flow. The gases were chosen because of the likelihood that they will not permanently contaminate the model or tunnel. Twenty-four gases were identified as possibly suitable and four of these were tested from which it was concluded that surface flow direction can be shown by the method. Other flow details might also be detectable. The cryogenic wind tunnel used was insulated on the outside and did not show signs of contamination.

  14. Laboratory Visualization Experiments of Temperature-induced Fractures Around a Borehole (Cryogenic Fracturing) in Shale and Analogue Rock Samples

    NASA Astrophysics Data System (ADS)

    Kneafsey, T. J.; Nakagawa, S.; Wu, Y. S.; Mukhopadhyay, S.

    2014-12-01

    In tight shales, hydraulic fracturing is the dominant method for improving reservoir permeability. However, injecting water-based liquids can induce formation damage and disposal problems, thus other techniques are being sought. One alternative to hydraulic fracturing is producing fractures thermally, using low-temperature fluids (cryogens). The primary consequence of thermal stimulation is that shrinkage fractures are produced around the borehole wall. Recently, cryogenic stimulation produced some promising results when the cryogen (typically liquid nitrogen and cold nitrogen gas) could be brought to reservoir depth. Numerical modeling also showed possible significant increases in gas production from a shale reservoir after cryogenic stimulation. However, geometry and the dynamic behavior of these thermally induced fractures under different stress regimes and rock anisotropy and heterogeneity is not yet well understood.Currently, we are conducting a series of laboratory thermal fracturing experiments on Mancos Shale and transparent glass blocks, by injecting liquid nitrogen under atmospheric pressure into room temperature blocks under various anisotropic stress states. The glass blocks allow clear optical visualization of fracture development and final fracturing patterns. For the shale blocks, X-ray CT is used to image both pre-existing and induced fractures. Also, the effect of borehole orientation with respect to the bedding planes and aligned preexisting fractures is examined. Our initial experiment on a uniaxially compressed glass block showed fracturing behavior which was distinctly different from conventional hydraulic fracturing. In addition to tensile fractures in the maximum principal stress directions, the thermal contraction by the cryogen induced (1) chaotic, spalling fractures around the borehole wall, and (2) a series of disk-shaped annular fractures perpendicular to the borehole. When applied to a horizontal borehole, the propagation plane of the

  15. Effects of Visual Experience on the Human MT+ Functional Connectivity Networks: An fMRI Study of Motion Perception in Sighted and Congenitally Blind Individuals

    PubMed Central

    Sani, Lorenzo; Ricciardi, Emiliano; Gentili, Claudio; Vanello, Nicola; Haxby, James V.; Pietrini, Pietro

    2010-01-01

    Human middle temporal complex (hMT+) responds also to the perception of non-visual motion in both sighted and early blind individuals, indicating a supramodal organization. Visual experience, however, leads to a segregation of hMT+ into a more anterior subregion, involved in the supramodal representation of motion, and a posterior subregion that processes visual motion only. In contrast, in congenitally blind subjects tactile motion activates the full extent of hMT+. Here, we used fMRI to investigate brain areas functionally connected with the two hMT+ subregions (seeds) during visual and tactile motion in sighted and blind individuals. A common functional connectivity network for motion processing, including bilateral ventral and dorsal extrastriate, inferior frontal, middle and inferior temporal areas, correlated with the two hMT+ seeds both in sighted and blind individuals during either visual or tactile motion, independently from the sensory modality through which the information was acquired. Moreover, ventral premotor, somatosensory, and posterior parietal areas correlated only with the anterior but not with the posterior portion of hMT+ in sighted subjects, and with both hMT+ seeds in blind subjects. Furthermore, a correlation between middle temporal and occipital areas with primary somatosensory seeds was demonstrated across conditions in both sighted and blind individuals, suggesting a cortico-cortical pathway that conveys non-visual information from somatosensory cortex, through posterior parietal regions, to ventral extrastriate cortex. These findings expand our knowledge about the development of the functional organization within hMT+ by showing that distinct patterns of brain functional correlations originate from the anterior and posterior hMT+ subregions as a result of visual experience. PMID:21191477

  16. Visual processing deficits in dyslexia: receptors or neural mechanisms?

    PubMed

    Stuart, G W; Lovegrove, W J

    1992-02-01

    In 1989 and 1990 Grosser and Spafford attributed abnormalities in the peripheral vision of dyslexic subjects to an anomalous distribution of rods and cones. We argue that at the light levels used in these experiments cone responses should dominate both central and peripheral vision. A more likely explanation of their findings is that there is a postreceptoral deficit in the transient visual channel. This hypothesis is supported by independent anatomical, physiological, and psychophysical evidence. PMID:1561023

  17. 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. PMID:25199609

  18. Major challenges to scale up of visual inspection-based cervical cancer prevention programs: the experience of Guatemalan NGOs

    PubMed Central

    Chary, Anita Nandkumar; Rohloff, Peter J

    2014-01-01

    ABSTRACT Background: Like many other low- and middle-income countries, Guatemala has adopted visual inspection with acetic acid (VIA) as a low-resource alternative to the Pap smear for cervical cancer screening. Nongovernmental organizations (NGOs) introduced VIA to Guatemala in 2004, and a growing number of NGOs, working both independently and in collaboration with the Guatemalan Ministry of Health, employ VIA in cervical cancer prevention programs today. While much research describes VIA efficacy and feasibility in Latin America, little is known about NGO involvement with VIA programming or experiences with VIA outside the context of clinical trials and pilot projects in the region. Methods: To explore challenges faced by NGOs implementing VIA programs in Guatemala, we conducted semi-structured interviews with 36 NGO staff members involved with 20 VIA programs as direct service providers, program administrators, and training course instructors. Additionally, we collected data through observation at 30 NGO-sponsored cervical cancer screening campaigns, 8 cervical cancer prevention conferences, and 1 week-long NGO-sponsored VIA training course. Results: Frequently highlighted challenges included staff turnover, concerns over training quality, a need for opportunities for continued supervision, and problems with cryotherapy referrals when immediate treatment for VIA-positive women was unavailable. Conclusions: Reducing staff turnover, budgeting to train replacement providers, standardizing training curricula, and offering continued supervision are key strategies to improve VIA service quality and program sustainability. Alternative training methods, such as on-the-job mentoring and course prerequisites of online learning, could help increase training time available for clinical supervision. Efforts should be made to ensure that VIA testing is coupled with immediate cryotherapy, that providers trained in VIA are also trained in cryotherapy, and that cryotherapy

  19. Vapor-screen flow-visualization experiments in the NASA Langley 0.3-m transonic cryogenic tunnel

    NASA Technical Reports Server (NTRS)

    Selby, G. V.

    1986-01-01

    The vortical flow on the leeward side of a delta-wing model has been visualized at several different tunnel conditions in the NASA Langley 0.3-Meter Transonic Cryogenic Tunnel using a vapor-screen flow-visualization technique. Vapor-screen photographs of the subject flow field are presented and interpreted relative to phenomenological implications. Results indicate that the use of nitrogen fog in conjunction with the vapor-screen technique is feasibile.

  20. KENeV: A web-application for the automated reconstruction and visualization of the enriched metabolic and signaling super-pathways deriving from genomic experiments.

    PubMed

    Pilalis, Eleftherios; Koutsandreas, Theodoros; Valavanis, Ioannis; Athanasiadis, Emmanouil; Spyrou, George; Chatziioannou, Aristotelis

    2015-01-01

    Gene expression analysis, using high throughput genomic technologies,has become an indispensable step for the meaningful interpretation of the underlying molecular complexity, which shapes the phenotypic manifestation of the investigated biological mechanism. The modularity of the cellular response to different experimental conditions can be comprehended through the exploitation of molecular pathway databases, which offer a controlled, curated background for statistical enrichment analysis. Existing tools enable pathway analysis, visualization, or pathway merging but none integrates a fully automated workflow, combining all above-mentioned modules and destined to non-programmer users. We introduce an online web application, named KEGG Enriched Network Visualizer (KENeV), which enables a fully automated workflow starting from a list of differentially expressed genes and deriving the enriched KEGG metabolic and signaling pathways, merged into two respective, non-redundant super-networks. The final networks can be downloaded as SBML files, for further analysis, or instantly visualized through an interactive visualization module. In conclusion, KENeV (available online at http://www.grissom.gr/kenev) provides an integrative tool, suitable for users with no programming experience, for the functional interpretation, at both the metabolic and signaling level, of differentially expressed gene subsets deriving from genomic experiments. PMID:26925206

  1. KENeV: A web-application for the automated reconstruction and visualization of the enriched metabolic and signaling super-pathways deriving from genomic experiments

    PubMed Central

    Pilalis, Eleftherios; Koutsandreas, Theodoros; Valavanis, Ioannis; Athanasiadis, Emmanouil; Spyrou, George; Chatziioannou, Aristotelis

    2015-01-01

    Gene expression analysis, using high throughput genomic technologies,has become an indispensable step for the meaningful interpretation of the underlying molecular complexity, which shapes the phenotypic manifestation of the investigated biological mechanism. The modularity of the cellular response to different experimental conditions can be comprehended through the exploitation of molecular pathway databases, which offer a controlled, curated background for statistical enrichment analysis. Existing tools enable pathway analysis, visualization, or pathway merging but none integrates a fully automated workflow, combining all above-mentioned modules and destined to non-programmer users. We introduce an online web application, named KEGG Enriched Network Visualizer (KENeV), which enables a fully automated workflow starting from a list of differentially expressed genes and deriving the enriched KEGG metabolic and signaling pathways, merged into two respective, non-redundant super-networks. The final networks can be downloaded as SBML files, for further analysis, or instantly visualized through an interactive visualization module. In conclusion, KENeV (available online at http://www.grissom.gr/kenev) provides an integrative tool, suitable for users with no programming experience, for the functional interpretation, at both the metabolic and signaling level, of differentially expressed gene subsets deriving from genomic experiments. PMID:26925206

  2. Morphological abnormalities in elasmobranchs.

    PubMed

    Moore, A B M

    2015-08-01

    A total of 10 abnormal free-swimming (i.e., post-birth) elasmobranchs are reported from The (Persian-Arabian) Gulf, encompassing five species and including deformed heads, snouts, caudal fins and claspers. The complete absence of pelvic fins in a milk shark Rhizoprionodon acutus may be the first record in any elasmobranch. Possible causes, including the extreme environmental conditions and the high level of anthropogenic pollution particular to The Gulf, are briefly discussed. PMID:25903257

  3. Chromosome abnormalities in glioma

    SciTech Connect

    Li, Y.S.; Ramsay, D.A.; Fan, Y.S.

    1994-09-01

    Cytogenetic studies were performed in 25 patients with gliomas. An interesting finding was a seemingly identical abnormality, an extra band on the tip of the short arm of chromosome 1, add(1)(p36), in two cases. The abnormality was present in all cells from a patient with a glioblastoma and in 27% of the tumor cells from a patient with a recurrent irradiated anaplastic astrocytoma; in the latter case, 7 unrelated abnormal clones were identified except 4 of those clones shared a common change, -Y. Three similar cases have been described previously. In a patient with pleomorphic astrocytoma, the band 1q42 in both homologues of chromosome 1 was involved in two different rearrangements. A review of the literature revealed that deletion of the long arm of chromosome 1 including 1q42 often occurs in glioma. This may indicate a possible tumor suppressor gene in this region. Cytogenetic follow-up studies were carried out in two patients and emergence of unrelated clones were noted in both. A total of 124 clonal breakpoints were identified in the 25 patients. The breakpoints which occurred three times or more were: 1p36, 1p22, 1q21, 1q25, 3q21, 7q32, 8q22, 9q22, 16q22, and 22q13.

  4. [Congenital foot abnormalities].

    PubMed

    Delpont, M; Lafosse, T; Bachy, M; Mary, P; Alves, A; Vialle, R

    2015-03-01

    The foot may be the site of birth defects. These abnormalities are sometimes suspected prenatally. Final diagnosis depends on clinical examination at birth. These deformations can be simple malpositions: metatarsus adductus, talipes calcaneovalgus and pes supinatus. The prognosis is excellent spontaneously or with a simple orthopedic treatment. Surgery remains outstanding. The use of a pediatric orthopedist will be considered if malposition does not relax after several weeks. Malformations (clubfoot, vertical talus and skew foot) require specialized care early. Clubfoot is characterized by an equine and varus hindfoot, an adducted and supine forefoot, not reducible. Vertical talus combines equine hindfoot and dorsiflexion of the forefoot, which is performed in the midfoot instead of the ankle. Skew foot is suspected when a metatarsus adductus is resistant to conservative treatment. Early treatment is primarily orthopedic at birth. Surgical treatment begins to be considered after walking age. Keep in mind that an abnormality of the foot may be associated with other conditions: malposition with congenital hip, malformations with syndromes, neurological and genetic abnormalities. PMID:25524290

  5. Electroencephalographic Abnormalities in Clozapine-Treated Patients: A Cross-Sectional Study

    PubMed Central

    Goyal, Nishant; Desarkar, Pushpal; Nizamie, Haque

    2011-01-01

    The objective of our study was to examine the electroencephalogram (EEG) abnormalities associated with clozapine treatment. It was a cross-sectional study on 87 psychiatric patients on clozapine treatment. 32 channel digital EEG was recorded and analysed visually for abnormalities. EEG abnormalities were observed in 63.2% of patients. Both slowing and epileptiform activities were noted in 41.4% of patients. The EEG abnormalities were not associated with dose or duration of clozapine exposure. PMID:22216049

  6. 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

  7. 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.

  8. ["...cause in such a big hospital ... visually impaired persons like me, alone, can't get anywhere"--the experience of visually impaired people of the in-patient care--an empirical, explorative study].

    PubMed

    Golde, Christian

    2007-02-01

    The aim of this study is to explore the experiences of people with visual impairment within in-patient care. Actually, in nursing literature, no similar research is known in the German speaking area. Therefore, an qualitative research framework was used. By using a convenience sampling eight participants have been chosen. Mainly, the thematic content analysis of Burnard has been applied to the analysis of the empirical data. Mental spatial concepts for orientation, primarily acoustically made communicative resonance fields, and Action techniques constitute three major topics, which have been categorised in this study. These concepts are discussed in the cause of the research with respect to their implications on nursing care. PMID:17294372

  9. Abnormal human sex chromosome constitutions

    SciTech Connect

    1993-12-31

    Chapter 22, discusses abnormal human sex chromosome constitution. Aneuploidy of X chromosomes with a female phenotype, sex chromosome aneuploidy with a male phenotype, and various abnormalities in X chromosome behavior are described. 31 refs., 2 figs.

  10. Exercises to Improve Gait Abnormalities

    MedlinePlus

    ... Home About iChip Articles Directories Videos Resources Contact Exercises to Improve Gait Abnormalities Home » Article Categories » Exercise and Fitness Font Size: A A A A Exercises to Improve Gait Abnormalities Next Page The manner ...

  11. A conceptual model for facilitating learning from physics tasks using visual cueing and outcome feedback: Theory and experiments

    NASA Astrophysics Data System (ADS)

    Agra, Elise Stacey Garasi

    This dissertation investigates the effects of visual cueing and outcome feedback on students' performance, confidence, and visual attention as they solve conceptual physics problems that contain diagrams. The research investigation had two parts. In the first part of the study, participants solved four sets of conceptual physics problems that contain diagrams; each set contained an initial problem, four isomorphic training problems, a near transfer problem (with a slightly different surface feature as the training problems), and a far transfer problem (with considerably different surface feature as the training problems). Participants in the cued conditions saw visual cues overlaid on the training problem diagrams, while those in the feedback conditions were told if their responses were correct or incorrect. In the second part of the study, the same students solved the near and far transfer problems from the first study two weeks later. We found that the combination of visual cueing and outcome feedback improved performance on the near transfer and delayed near transfer problems compared to the initial problem, with no significant difference between them. Thus, the combination of visual cueing and outcome feedback can promote immediate learning and retention. For students who demonstrated immediate learning and retention on the near and far transfer problems, visual cues improved the automaticity of extracting relevant information from the transfer and delayed transfer problem diagrams, while outcome feedback helped automatize the extraction of problem-relevant information on the delayed far transfer problem diagram only. We also showed that students' reported confidence in solving a problem is positively related to their correctness on the problem, and their visual attention to the relevant information on the problem diagram. The most interesting thing was how changes in confidence occurred due to outcome feedback, which were also related to changes in accuracy

  12. Abnormalities of the Erythrocyte Membrane

    PubMed Central

    Gallagher, Patrick G.

    2014-01-01

    Synopsis Primary abnormalities of the erythrocyte membrane, including the hereditary spherocytosis and hereditary elliptocytosis syndromes, are an important group of inherited hemolytic anemias. Classified by distinctive morphology on peripheral blood smear, these disorders 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. Once considered routine, growing recognition of the longterm risks of splenectomy, including cardiovascular disease, thrombotic disorders, and pulmonary hypertension, as well as the emergence of penicillin-resistant pneumococci, a concern for infection in overwhelming postsplenectomy infection, have led to re-evaluation of the role of splenectomy. Current management guidelines acknowledge these important considerations when entertaining splenectomy and recommend detailed 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. PMID:24237975

  13. Using Virtual Microscopy to Scaffold Learning of Pathology: A Naturalistic Experiment on the Role of Visual and Conceptual Cues

    ERIC Educational Resources Information Center

    Nivala, Markus; Saljo, Roger; Rystedt, Hans; Kronqvist, Pauliina; Lehtinen, Erno

    2012-01-01

    New representational technologies, such as virtual microscopy, create new affordances for medical education. In the article, a study on the following two issues is reported: (a) How does collaborative use of virtual microscopy shape students' engagement with and learning from virtual slides of tissue specimen? (b) How do visual and conceptual cues…

  14. An Investigation of the Effectiveness of Visual-Motor Experiences in the Development of the Ability to Conserve Mass.

    ERIC Educational Resources Information Center

    Champagne, Audrey Ann Briggs

    Based on the work of Bruner, Piaget and others that indicates that the child's attention to misleading visual clues is an important factor in his lack of ability to conserve, this study is an attempt to demonstrate the effects of instruction in drawing two-dimensional figures on the ability of children (22 kindergarten children from middle class…

  15. Spirometric abnormalities among welders

    SciTech Connect

    Rastogi, S.K.; Gupta, B.N.; Husain, T.; Mathur, N.; Srivastava, S. )

    1991-10-01

    A group of manual welders age group 13-60 years having a mean exposure period of 12.4 {plus minus} 1.12 years were subjected to spirometry to evaluate the prevalence of spirometric abnormalities. The welders showed a significantly higher prevalence of respiratory impairment than that observed among the unexposed controls as a result of exposure to welding gases which comprised fine particles of lead, zinc, chromium, and manganese. This occurred despite the lower concentration of the pollutants at the work place. In the expose group, the smoking welders showed a prevalence of respiratory impairment significantly higher than that observed in the nonsmoking welders. The results of the pulmonary function tests showed a predominantly restrictive type of pulmonary impairment followed by a mixed ventilatory defect among the welders. The effect of age on pulmonary impairment was not discernible. Welders exposed for over 10 years showed a prevalence of respiratory abnormalities significantly higher than those exposed for less than 10 years. Smoking also had a contributory role.

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

    PubMed

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

    2013-10-01

    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

  17. 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

  18. Development of a magnetic resonance imaging protocol to visualize encapsulated contrast agent markers in prostate brachytherapy recipients: initial patient experience

    PubMed Central

    Lim, Tze Yee; Wang, Jihong; Bathala, Tharakeswara; Szklaruk, Janio; Pugh, Thomas J.; Mahmood, Usama; Ibbott, Geoffrey S.; Frank, Steven J.

    2016-01-01

    Purpose Computed tomography (CT)-based prostate post-implant dosimetry allows for definitive seed localization but is associated with high interobserver variation in prostate contouring. Currently, magnetic resonance imaging (MRI)-based post-implant dosimetry allows for accurate anatomical delineation but is limited due to inconsistent seed localization. Encapsulated contrast agent markers were previously proposed to overcome the seed localization limitation on MRI images by placing hyperintense markers adjacent to hypointense seeds. The aim of this study was to assess the appearance of these markers in prostatic tissue, and develop an MRI protocol to enable marker visualization. Material and methods We acquired MRI scans in prostate implant patients (n = 10) on day 0 (day of implant) and day 30 (month after implant). Before implantation of the markers, the routine post-implant MRI protocol included a 3D T2-weighted fast-spin-echo (FSE) sequence with which markers and seeds could not be clearly visualized. To visualize the MRI markers, a 3D fast radiofrequency-spoiled gradient-recalled echo (FSPGR) sequence was evaluated for marker and seed visibility, as well as prostate boundary definitions. Results The 3D FSPGR sequence allowed for the visualization of markers in the prostate, enabling the distinction of signal voids as seeds versus needle tracks. The updated post-implant MRI protocol consists of this 3D FSPGR scan and an optional 3D T2-weighted FSE scan. The optional 3D T2-weighted FSE sequence may be employed to better visualize intraprostatic detail. We also described the observed image artifacts, including seed susceptibility, marker chemical shift, partial volume averaging, motion, and wraparound artifacts. Conclusions We have demonstrated an MRI protocol for use with hyperintense encapsulated contrast agent markers to assist in the identification of hypointense seeds. PMID:27504133

  19. Visual field

    MedlinePlus

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam : This is a quick and basic check of the visual field. The health care provider ...

  20. Visual Learning.

    ERIC Educational Resources Information Center

    Kirrane, Diane E.

    1992-01-01

    An increasingly visual culture is affecting work and training. Achievement of visual literacy means acquiring competence in critical analysis of visual images and in communicating through visual media. (SK)

  1. Visual field

    MedlinePlus

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam : This is a quick and basic check of the visual field. The health care provider sits directly in front ...

  2. Parsing abnormal grain growth in specialty aluminas

    NASA Astrophysics Data System (ADS)

    Lawrence, Abigail Kremer

    Grain growth in alumina is strongly affected by the impurities present in the material. Certain impurity elements are known to have characteristic effects on abnormal grain growth in alumina. Specialty alumina powders contain multiple impurity species including MgO, CaO, SiO2, and Na 2O. In this work, sintered samples made from alumina powders containing various amounts of the impurities in question were characterized by their grain size and aspect ratio distributions. Multiple quantitative methods were used to characterize and classify samples with varying microstructures. The grain size distributions were used to partition the grain size population into subpopulations depending on the observed deviation from normal behavior. Using both grain size and aspect ratio a new visual representation for a microstructure was introduced called a morphology frequency map that gives a fingerprint for the material. The number of subpopulations within a sample and the shape of the distribution on the morphology map provided the basis for a classification scheme for different types of microstructures. Also using the two parameters a series of five metrics were calculated that describe the character of the abnormal grains in the sample, these were called abnormal character values. The abnormal character values describe the fraction of grains that are considered abnormal, the average magnitude of abnormality (including both grain size and aspect ratio), the average size, and variance in size. The final metric is the correlation between grain size and aspect ratio for the entire population of grains. The abnormal character values give a sense of how different from "normal" the sample is, given the assumption that a normal sample has a lognormal distribution of grain size and a Gaussian distribution of aspect ratios. In the second part of the work the quantified measures of abnormality were correlated with processing parameters such as composition and heat treatment conditions. A

  3. [Investigation of the threshold characteristics of visual information perception by operator controlling the illumination parameters in the 105-day experiment in isolation].

    PubMed

    Bogatova, R I; Gvozdev, S M; Sal'nitskiĭ, V P; Kutina, I V; Sadovnikova, N D; Artiukhova, A E; Liventsova, A A; Tiatykh, I V

    2011-01-01

    The investigations of threshold frequency characteristics (TFC) of the visual analyzer and labor productivity were carried out during 105-d isolation of volunteers in an airtight module illuminated by LED lamps adjustable to personal psychophysiological needs. Software and calculation procedure were devised to assist the chromatic TFC-based determination of photometric parameters. Data of analysis of actual mood and vision contrast sensitivity when looking at a three-color image suggested that visual performance could be improved by achieving light color adequacy to TFC of individual vision. The results of experimental investigations showed once again efficiency of the proposed methods and their relevance to the objectives of the extended ground-based experiment simulating an exploration mission to Mars. PMID:21916248

  4. Visual disorders in children with brain lesions: 2. Visual impairment associated with cerebral palsy.

    PubMed

    Guzzetta, A; Mercuri, E; Cioni, G

    2001-01-01

    Disorders of visual function are a common finding in children with cerebral palsy. In some cases they are secondary to ophthalmologic abnormalities such as cataract or retinopathy, but more often they are due to damage of the central visual pathway. We review the literature on the prevalence and distribution of visual abnormalities in children with cerebral palsy and their relation to cognitive, motor and emotional development. PMID:11589165

  5. Experience-dependent plasticity in the inferior colliculus: a site for visual calibration of the neural representation of auditory space in the barn owl.

    PubMed

    Brainard, M S; Knudsen, E I

    1993-11-01

    The optic tectum (homolog of the superior colliculus) contains mutually aligned neural maps of auditory and visual space. During development, the organization of the auditory map is guided by spatial information provided by vision: barn owls raised wearing prismatic spectacles, which optically shift the visual field and the visual map in the optic tectum, develop an auditory map that is shifted by an approximately equivalent amount, such that alignment between the two maps is preserved (Knudsen and Brainard, 1991). In this study we investigated whether this shift in the auditory map is intrinsic to the optic tectum or whether it reflects plasticity at an earlier stage in the auditory pathway. Owls were raised wearing prismatic spectacles that displaced the visual field by 23 degrees to the left or right. This manipulation alters the normal correspondence between locations in the visual field and interaural time difference (ITD), the primary cue for the azimuth of a sound source. In normal owls and in owls with at least 150 d of prism experience, extracellular unit recordings were used to assess the representations of ITD at anatomically and physiologically defined sites in the optic tectum and in the two prior stages of the auditory pathway, the external and central nuclei of the inferior colliculus (ICx and ICc). In the optic tectum of normal owls, the values of ITD to which units responded most strongly (best ITDs) varied systematically with the azimuths of unit visual receptive fields (VRFs). In the prism-reared owls, best ITDs were shifted from normal toward the values of ITD produced by sounds at the locations of the units' optically displaced VRFs. In the ICx of prism-reared owls, the representation of ITD also was shifted from normal, by an amount and in a direction that could completely account for the shift in ITD measured in the optic tectum. At some sites in the ICx, the shift in ITD tuning was apparent within the first 7-8 msec of the response; shifted

  6. Eye movement abnormalities.

    PubMed

    Moncayo, Jorge; Bogousslavsky, Julien

    2012-01-01

    Generation and control of eye movements requires the participation of the cortex, basal ganglia, cerebellum and brainstem. The signals of this complex neural network finally converge on the ocular motoneurons of the brainstem. Infarct or hemorrhage at any level of the oculomotor system (though more frequent in the brain-stem) may give rise to a broad spectrum of eye movement abnormalities (EMAs). Consequently, neurologists and particularly stroke neurologists are routinely confronted with EMAs, some of which may be overlooked in the acute stroke setting and others that, when recognized, may have a high localizing value. The most complex EMAs are due to midbrain stroke. Horizontal gaze disorders, some of them manifesting unusual patterns, may occur in pontine stroke. Distinct varieties of nystagmus occur in cerebellar and medullary stroke. This review summarizes the most representative EMAs from the supratentorial level to the brainstem. PMID:22377853

  7. 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.

  8. Abnormal magnetic field effects on electrogenerated chemiluminescence.

    PubMed

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

    2015-01-01

    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)3(3+) … 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)3(3+) … TPrA(•)] complexes in solution at room temperature. PMID:25772580

  9. Abnormal Magnetic Field Effects on Electrogenerated Chemiluminescence

    PubMed Central

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

    2015-01-01

    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. PMID:25772580

  10. 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

  11. Declarative Visualization Queries

    NASA Astrophysics Data System (ADS)

    Pinheiro da Silva, P.; Del Rio, N.; Leptoukh, G. G.

    2011-12-01

    In an ideal interaction with machines, scientists may prefer to write declarative queries saying "what" they want from a machine than to write code stating "how" the machine is going to address the user request. For example, in relational database, users have long relied on specifying queries using Structured Query Language (SQL), a declarative language to request data results from a database management system. In the context of visualizations, we see that users are still writing code based on complex visualization toolkit APIs. With the goal of improving the scientists' experience of using visualization technology, we have applied this query-answering pattern to a visualization setting, where scientists specify what visualizations they want generated using a declarative SQL-like notation. A knowledge enhanced management system ingests the query and knows the following: (1) know how to translate the query into visualization pipelines; and (2) how to execute the visualization pipelines to generate the requested visualization. We define visualization queries as declarative requests for visualizations specified in an SQL like language. Visualization queries specify what category of visualization to generate (e.g., volumes, contours, surfaces) as well as associated display attributes (e.g., color and opacity), without any regards for implementation, thus allowing scientists to remain partially unaware of a wide range of visualization toolkit (e.g., Generic Mapping Tools and Visualization Toolkit) specific implementation details. Implementation details are only a concern for our knowledge-based visualization management system, which uses both the information specified in the query and knowledge about visualization toolkit functions to construct visualization pipelines. Knowledge about the use of visualization toolkits includes what data formats the toolkit operates on, what formats they output, and what views they can generate. Visualization knowledge, which is not

  12. 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

  13. Ictal Cardiac Ryhthym Abnormalities

    PubMed Central

    Ali, Rushna

    2016-01-01

    Cardiac rhythm abnormalities in the context of epilepsy are a well-known phenomenon. However, they are under-recognized and often missed. The pathophysiology of these events is unclear. Bradycardia and asystole are preceded by seizure onset suggesting ictal propagation into the cortex impacting cardiac autonomic function, and the insula and amygdala being possible culprits. Sudden unexpected death in epilepsy (SUDEP) refers to the unanticipated death of a patient with epilepsy not related to status epilepticus, trauma, drowning, or suicide. Frequent refractory generalized tonic-clonic seizures, anti-epileptic polytherapy, and prolonged duration of epilepsy are some of the commonly identified risk factors for SUDEP. However, the most consistent risk factor out of these is an increased frequency of generalized tonic–clonic seizures (GTC). Prevention of SUDEP is extremely important in patients with chronic, generalized epilepsy. Since increased frequency of GTCS is the most consistently reported risk factor for SUDEP, effective seizure control is the most important preventive strategy. PMID:27347227

  14. Abnormal uterine bleeding.

    PubMed

    Whitaker, Lucy; Critchley, Hilary O D

    2016-07-01

    Abnormal uterine bleeding (AUB) is a common and debilitating condition with high direct and indirect costs. AUB frequently co-exists with fibroids, but the relationship between the two remains incompletely understood and in many women the identification of fibroids may be incidental to a menstrual bleeding complaint. A structured approach for establishing the cause using the Fédération International de Gynécologie et d'Obstétrique (FIGO) PALM-COEIN (Polyp, Adenomyosis, Leiomyoma, Malignancy (and hyperplasia), Coagulopathy, Ovulatory disorders, Endometrial, Iatrogenic and Not otherwise classified) classification system will facilitate accurate diagnosis and inform treatment options. Office hysteroscopy and increasing sophisticated imaging will assist provision of robust evidence for the underlying cause. Increased availability of medical options has expanded the choice for women and many will no longer need to recourse to potentially complicated surgery. Treatment must remain individualised and encompass the impact of pressure symptoms, desire for retention of fertility and contraceptive needs, as well as address the management of AUB in order to achieve improved quality of life. PMID:26803558

  15. Do you see what I hear: experiments in multi-channel sound and 3D visualization for network monitoring?

    NASA Astrophysics Data System (ADS)

    Ballora, Mark; Hall, David L.

    2010-04-01

    Detection of intrusions is a continuing problem in network security. Due to the large volumes of data recorded in Web server logs, analysis is typically forensic, taking place only after a problem has occurred. This paper describes a novel method of representing Web log information through multi-channel sound, while simultaneously visualizing network activity using a 3-D immersive environment. We are exploring the detection of intrusion signatures and patterns, utilizing human aural and visual pattern recognition ability to detect intrusions as they occur. IP addresses and return codes are mapped to an informative and unobtrusive listening environment to act as a situational sound track of Web traffic. Web log data is parsed and formatted using Python, then read as a data array by the synthesis language SuperCollider [1], which renders it as a sonification. This can be done either for the study of pre-existing data sets or in monitoring Web traffic in real time. Components rendered aurally include IP address, geographical information, and server Return Codes. Users can interact with the data, speeding or slowing the speed of representation (for pre-existing data sets) or "mixing" sound components to optimize intelligibility for tracking suspicious activity.

  16. The Experience of Force: The Role of Haptic Experience of Forces in Visual Perception of Object Motion and Interactions, Mental Simulation, and Motion-Related Judgments

    ERIC Educational Resources Information Center

    White, Peter A.

    2012-01-01

    Forces are experienced in actions on objects. The mechanoreceptor system is stimulated by proximal forces in interactions with objects, and experiences of force occur in a context of information yielded by other sensory modalities, principally vision. These experiences are registered and stored as episodic traces in the brain. These stored…

  17. Imagine that: elevated sensory strength of mental imagery in individuals with Parkinson's disease and visual hallucinations

    PubMed Central

    Shine, James M.; Keogh, Rebecca; O'Callaghan, Claire; Muller, Alana J.; Lewis, Simon J. G.; Pearson, Joel

    2015-01-01

    Visual hallucinations occur when our conscious experience does not accurately reflect external reality. However, these dissociations also regularly occur when we imagine the world around us in the absence of visual stimulation. We used two novel behavioural paradigms to objectively measure visual hallucinations and voluntary mental imagery in 19 individuals with Parkinson's disease (ten with visual hallucinations; nine without) and ten healthy, age-matched controls. We then used this behavioural overlap to interrogate the connectivity both within and between the major attentional control networks using resting-state functional magnetic resonance imaging. Patients with visual hallucinations had elevated mental imagery strength compared with patients without hallucinations and controls. Specifically, the sensory strength of imagery predicted the frequency of visual hallucinations. Together, hallucinations and mental imagery predicted multiple abnormalities in functional connectivity both within and between the attentional control networks, as measured with resting-state functional magnetic resonance imaging. However, the two phenomena were also dissociable at the neural level, with both mental imagery and visual misperceptions associated with specific abnormalities in attentional network connectivity. Our results provide the first evidence of both the shared and unique neural correlates of these two similar, yet distinct phenomena. PMID:25429016

  18. 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. PMID:2461390

  19. Electrocardiograph abnormalities revealed during laparoscopy

    PubMed Central

    Nijjer, Sukhjinder; Dubrey, Simon William

    2010-01-01

    This brief case presents a well patient in whom an electrocardiograph abnormality consistent with an accessory pathway was found during a routine procedure. We present the electrocardiographs, explain the underlying condition, and consider why the abnormality was revealed in this manner. PMID:22419949

  20. 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.

  1. Haem degradation in abnormal haemoglobins.

    PubMed Central

    Brown, S B; Docherty, J C

    1978-01-01

    The coupled oxidation of certain abnormal haemoglobins leads to different bile-pigment isomer distributions from that of normal haemoglobin. The isomer pattern may be correlated with the structure of the abnormal haemoglobin in the neighbourhood of the haem pocket. This is support for haem degradation by an intramolecular reaction. PMID:708385

  2. Automatic classification of squamosal abnormality in micro-CT images for the evaluation of rabbit fetal skull defects using active shape models

    NASA Astrophysics Data System (ADS)

    Chen, Antong; Dogdas, Belma; Mehta, Saurin; Bagchi, Ansuman; Wise, L. David; Winkelmann, Christopher

    2014-03-01

    High-throughput micro-CT imaging has been used in our laboratory to evaluate fetal skeletal morphology in developmental toxicology studies. Currently, the volume-rendered skeletal images are visually inspected and observed abnormalities are reported for compounds in development. To improve the efficiency and reduce human error of the evaluation, we implemented a framework to automate the evaluation process. The framework starts by dividing the skull into regions of interest and then measuring various geometrical characteristics. Normal/abnormal classification on the bone segments is performed based on identifying statistical outliers. In pilot experiments using rabbit fetal skulls, the majority of the skeletal abnormalities can be detected successfully in this manner. However, there are shape-based abnormalities that are relatively subtle and thereby difficult to identify using the geometrical features. To address this problem, we introduced a model-based approach and applied this strategy on the squamosal bone. We will provide details on this active shape model (ASM) strategy for the identification of squamosal abnormalities and show that this method improved the sensitivity of detecting squamosal-related abnormalities from 0.48 to 0.92.

  3. Behavioral abnormalities in captive nonhuman primates.

    PubMed

    Mallapur, Avanti; Choudhury, B C

    2003-01-01

    In this study, we dealt with 11 species of nonhuman primates across 10 zoos in India. We recorded behavior as instantaneous scans between 9 a.m. and 5 p.m. In the study, we segregated behaviors for analyses into abnormal, undesirable, active, and resting. The 4 types of abnormal behavior exhibited included floating limb, self-biting, self-clasping, and stereotypic pacing. In the study, we recorded 2 types of undesirable behavior: autoerotic stimulation and begging. Langurs and group-housed macaques did not exhibit undesirable behaviors. A male lion-tailed macaque and a male gibbon exhibited begging behavior. autoerotic stimulation and self-biting occurred rarely. Males exhibited higher levels of undesirable behavior than did females. Animals confiscated from touring zoos, circuses, and animal traders exhibited higher levels of abnormal behaviors than did animals reared in larger, recognized zoos. The stump-tailed macaque was the only species to exhibit floating limb, autoerotic stimulation, self-biting, and self-clasping. Our results show that rearing experience and group composition influence the proportions of abnormal behavior exhibited by nonhuman primates in captivity. The history of early social and environmental deprivation in these species of captive nonhuman primates probably is critical in the development of behavioral pathologies. Establishing this will require further research. PMID:14965782

  4. 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. PMID:26209358

  5. Selective fovea-related deprived activation in retinotopic and high-order visual cortex of human amblyopes.

    PubMed

    Lerner, Y; Hendler, T; Malach, R; Harel, M; Leiba, H; Stolovitch, C; Pianka, P

    2006-10-15

    Amblyopia is a visual disorder starting at early childhood and characterized by reduced visual acuity not of optical origin or due to any eye disease. One expression of such an anomalous early visual experience is abnormal foveal vision. In a previous fMRI study, faces that were presented to amblyopic eyes evoked little response compared to houses in high-order visual areas. Patients also demonstrated reduced recognition of facial expression, raising the possibility that these face-selective abnormalities are related to foveal vision deficit. Whether this deficit originates in low-level processing or is mediated by compromised activation in high-order visual areas is unresolved. In the present functional magnetic resonance imaging (fMRI) study, we explored the impact of amblyopia on the representation of object images presented in foveally biased central versus peripheral retinotopic eccentricities through manipulation of object size. Small and large pictures were correlated to visual acuities of 6/6 and 6/60, respectively. In low-level visual areas, the amblyopic eye showed significantly reduced activation for centrally placed, small pictures than the sound eye, while activation to large pictures was only slightly reduced. Similarly, in high-order visual areas, the amblyopic eye showed marked reduction in activation in the fusiform gyrus, with normal activation in the collateral sulcus. The center/periphery size-related amblyopic outcomes of this study support a "bottom-up" nature of the center-periphery effect observed in high-order visual areas. Taken together, these findings point to the regional extent and functional selectivity of fovea-related cortical reorganization that is related to abnormal visual development of one eye. PMID:16919483

  6. Electroencephalographic abnormalities in antisocial personality disorder.

    PubMed

    Calzada-Reyes, Ana; Alvarez-Amador, Alfredo; Galán-García, Lídice; Valdés-Sosa, Mitchell

    2012-01-01

    The presence of brain dysfunction in violent offenders has been frequently examined with inconsistent results. The aim of the study was to assess the EEG of 84 violent offenders by visual inspection and frequency-domain quantitative analysis in 84 violent prisoners. Low-resolution electromagnetic tomography (LORETA) was also employed for theta band of the EEG spectra. Antisocial personality disorder (ASPD) was present in 50 of the offenders and it was absent in the remaining 34. The prevalence of EEG abnormalities, by visual inspection, was similar for both the ASPD group (82%) and non-ASPD group (79%). The brain topography of these anomalies also did not differ between groups, in contrast to results of the EEG quantitative analysis (QEEG) and LORETA that showed remarkable regional differences between both groups. QEEG analysis showed a pattern of excess of theta-delta activities and decrease of alpha band on the right fronto-temporal and left temporo-parietal regions in the ASPD group. LORETA signified an increase of theta activity (5.08 Hz) in ASPD group relative to non-ASPD group within left temporal and parietal regions. Findings indicate that QEEG analysis and techniques of source localization may reveal differences in brain electrical activity among offenders with ASPD, which was not obvious to visual inspection. PMID:22152445

  7. Multidimensional Visual Statistical Learning

    ERIC Educational Resources Information Center

    Turk-Browne, Nicholas B.; Isola, Phillip J.; Scholl, Brian J.; Treat, Teresa A.

    2008-01-01

    Recent studies of visual statistical learning (VSL) have demonstrated that statistical regularities in sequences of visual stimuli can be automatically extracted, even without intent or awareness. Despite much work on this topic, however, several fundamental questions remain about the nature of VSL. In particular, previous experiments have not…

  8. Design for Visual Arts.

    ERIC Educational Resources Information Center

    Skeries, Larry

    Experiences suggested within this visual arts packet provide high school students with awareness of visual expression in graphic design, product design, architecture, and crafts. The unit may be used in whole or in part and includes information about art careers and art-related jobs found in major occupational fields. Specific lesson topics…

  9. Visualization of relaminarizing flows

    NASA Technical Reports Server (NTRS)

    Viswanath, P. R.; Narasimha, R.; Prabhu, A.

    1978-01-01

    The experiments described in the present paper provided conclusive evidence for the feasibility of achieving reverse transition by several different mechanisms. Turbulent-to-laminar transition in water was visualized by injection of purple and green dyes. Air flows were visualized by colored schlieren photography.

  10. Chromosomal abnormalities in human sperm

    SciTech Connect

    Martin, R.H.

    1985-01-01

    The ability to analyze human sperm chromosome complements after penetration of zona pellucida-free hamster eggs provides the first opportunity to study the frequency and type of chromosomal abnormalities in human gametes. Two large-scale studies have provided information on normal men. We have studied 1,426 sperm complements from 45 normal men and found an abnormality rate of 8.9%. Brandriff et al. (5) found 8.1% abnormal complements in 909 sperm from 4 men. The distribution of numerical and structural abnormalities was markedly dissimilar in the 2 studies. The frequency of aneuploidy was 5% in our sample and only 1.6% in Brandriff's, perhaps reflecting individual variability among donors. The frequency of 24,YY sperm was low: 0/1,426 and 1/909. This suggests that the estimates of nondisjunction based on fluorescent Y body data (1% to 5%) are not accurate. We have also studied men at increased risk of sperm chromosomal abnormalities. The frequency of chromosomally unbalanced sperm in 6 men heterozygous for structural abnormalities varied dramatically: 77% for t11;22, 32% for t6;14, 19% for t5;18, 13% for t14;21, and 0% for inv 3 and 7. We have also studied 13 cancer patients before and after radiotherapy and demonstrated a significant dose-dependent increase of sperm chromosome abnormalities (numerical and structural) 36 months after radiation treatment.

  11. A ballistic compressor-based experiment for the visualization of liquid propellant jet combustion above 100 MPa

    NASA Astrophysics Data System (ADS)

    Birk, A.; Kooker, D. E.

    This paper describes the components and operation of an experimental setup for the visualization of liquid propellant (LP) jet combustion at pressures above 100 MPa. The apparatus consists of an in-line ballistic compressor and LP injector. The ballistic compressor, based on a modified 76 mm gun, provides high-pressure (ca. 55 MPa) clear hot gas for the jet ignition. A piston (projectile) is fired toward a test chamber beyond the barrel's end, and its rebound is arrested in a transition section that seals the test chamber to the barrel. The LP jet is injected once the piston is restrained, and combustion of the jet further elevates the pressure. At a preset pressure, a disc in the piston ruptures and the combustion gas vents sonically into the barrel. If a monopropellant is used, the jet injection-combustion process then resembles liquid rocket combustion but at very high pressures (ca. 140 MPa). This paper discusses the ballistics of the compression and compares experimental results to those predicted by a numerical model of the apparatus. Experimentally, a pressure of 70 MPa was achieved upon a 12.5 volumetric compression factor by firing a 10 kg piston into 1.04 MPa argon using a charge of 75 g of small-grain M1 propellant.

  12. Haematological abnormalities in mitochondrial disorders

    PubMed Central

    Finsterer, Josef; Frank, Marlies

    2015-01-01

    INTRODUCTION This study aimed to assess the kind of haematological abnormalities that are present in patients with mitochondrial disorders (MIDs) and the frequency of their occurrence. METHODS The blood cell counts of a cohort of patients with syndromic and non-syndromic MIDs were retrospectively reviewed. MIDs were classified as ‘definite’, ‘probable’ or ‘possible’ according to clinical presentation, instrumental findings, immunohistological findings on muscle biopsy, biochemical abnormalities of the respiratory chain and/or the results of genetic studies. Patients who had medical conditions other than MID that account for the haematological abnormalities were excluded. RESULTS A total of 46 patients (‘definite’ = 5; ‘probable’ = 9; ‘possible’ = 32) had haematological abnormalities attributable to MIDs. The most frequent haematological abnormality in patients with MIDs was anaemia. 27 patients had anaemia as their sole haematological problem. Anaemia was associated with thrombopenia (n = 4), thrombocytosis (n = 2), leucopenia (n = 2), and eosinophilia (n = 1). Anaemia was hypochromic and normocytic in 27 patients, hypochromic and microcytic in six patients, hyperchromic and macrocytic in two patients, and normochromic and microcytic in one patient. Among the 46 patients with a mitochondrial haematological abnormality, 78.3% had anaemia, 13.0% had thrombopenia, 8.7% had leucopenia and 8.7% had eosinophilia, alone or in combination with other haematological abnormalities. CONCLUSION MID should be considered if a patient’s abnormal blood cell counts (particularly those associated with anaemia, thrombopenia, leucopenia or eosinophilia) cannot be explained by established causes. Abnormal blood cell counts may be the sole manifestation of MID or a collateral feature of a multisystem problem. PMID:26243978

  13. Estimating Synaphobranchus kaupii densities: Contribution of fish behaviour to differences between bait experiments and visual strip transects

    NASA Astrophysics Data System (ADS)

    Trenkel, Verena M.; Lorance, Pascal

    2011-01-01

    Kaup's arrowtooth eel Synaphobranchus kaupii is a small-bodied fish and an abundant inhabitant of the European continental slope. To estimate its local density video information using the remotely operated vehicle (ROV) Victor 6000 were collected at three locations in the Bay of Biscay slope. Two methods for estimating local densities were tested: strip transect counts and bait experiments. For bait experiments three behaviour types were observed in about equal proportions for individuals arriving near the seafloor: moving up the current towards the ROV, moving across the current and drifting with the current. Visible attraction towards the bait was the highest for individuals swimming against the current (80%) and about equally low for the other two types (around 30%); it did not depend on current speed nor temperature. Three main innovations were introduced for estimating population densities from bait experiments: (i) inclusion of an additional behaviour category—that of passively drifting individuals, (ii) inclusion of reaction behaviour for actively swimming individuals and (iii) a hierarchical Bayesian estimation framework. The results indicated that about half of individuals were foraging actively of which less than one third reacted on encountering the bait plume and the other half were drifting with the current. Taking account of drifting individuals and the reaction probability made density estimates from bait experiments and strip transects more similar.

  14. Destination Raval Sud: A Visual Ethnography on Pedagogy, Aesthetics, and the Spatial Experience of Growing Up Urban

    ERIC Educational Resources Information Center

    Trafi-Prats, Laura

    2009-01-01

    This article focuses on issues of childhood identity and urban environment. It discusses how a performance art pedagogy inspired by nomadic and relational aesthetics can provide a framework to promote creative learning experiences that address migratory conditions and forms of public alienation lived by young people today. As Lefebvre (1991)…

  15. Visual agnosia.

    PubMed

    Álvarez, R; Masjuan, J

    2016-03-01

    Visual agnosia is defined as an impairment of object recognition, in the absence of visual acuity or cognitive dysfunction that would explain this impairment. This condition is caused by lesions in the visual association cortex, sparing primary visual cortex. There are 2 main pathways that process visual information: the ventral stream, tasked with object recognition, and the dorsal stream, in charge of locating objects in space. Visual agnosia can therefore be divided into 2 major groups depending on which of the two streams is damaged. The aim of this article is to conduct a narrative review of the various visual agnosia syndromes, including recent developments in a number of these syndromes. PMID:26358494

  16. 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

  17. Visual capture and the experience of having two bodies – Evidence from two different virtual reality techniques

    PubMed Central

    Heydrich, Lukas; Dodds, Trevor J.; Aspell, Jane E.; Herbelin, Bruno; Bülthoff, Heinrich H.; Mohler, Betty J.; Blanke, Olaf

    2013-01-01

    In neurology and psychiatry the detailed study of illusory own body perceptions has suggested close links between bodily processing and self-consciousness. One such illusory own body perception is heautoscopy where patients have the sensation of being reduplicated and to exist at two or even more locations. In previous experiments, using a video head-mounted display, self-location and self-identification were manipulated by applying conflicting visuo-tactile information. Yet the experienced singularity of the self was not affected, i.e., participants did not experience having multiple bodies or selves. In two experiments presented in this paper, we investigated self-location and self-identification while participants saw two virtual bodies (video-generated in study 1 and 3D computer generated in study 2) that were stroked either synchronously or asynchronously with their own body. In both experiments, we report that self-identification with two virtual bodies was stronger during synchronous stroking. Furthermore, in the video generated setup with synchronous stroking participants reported a greater feeling of having multiple bodies than in the control conditions. In study 1, but not in study 2, we report that self-location – measured by anterior posterior drift – was significantly shifted towards the two bodies in the synchronous condition only. Self-identification with two bodies, the sensation of having multiple bodies, and the changes in self-location show that the experienced singularity of the self can be studied experimentally. We discuss our data with respect to ownership for supernumerary hands and heautoscopy. We finally compare the effects of the video and 3D computer generated head-mounted display technology and discuss the possible benefits of using either technology to induce changes in illusory self-identification with a virtual body. PMID:24385970

  18. 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…

  19. The effects of fixation and restricted visual field on vection-induced motion sickness

    NASA Technical Reports Server (NTRS)

    Stern, Robert M.; Hu, Senqi; Anderson, Richard B.; Leibowitz, Herschel W.; Koch, Kenneth L.

    1990-01-01

    Approximately 60 percent of healthy human subjects experience motion sickness when exposed to a rotating optokinetic drum. Here, the effects of certain visual factors on susceptibility to motion sickness were determined. Vection data (illusory self-motion), horizontal eye movement recordings, subjective motion sickness report, and a measure of gastric myoelectric activity were obtained from 45 subjects, who were randomly divided into the following three groups: a control group that observed the entire visual field with no fixation, a group that fixated on a central target, and a third group that had a visual field restricted to 15 deg. The experimental session was divided into three 12-min periods: baseline, drum rotation, and recovery. The results showed that fixation greatly reduced nystagmus and slightly reduced vection. The restricted visual field slightly reduced nystagmus and greatly reduced vection. Both of these manipulations significantly reduced symptoms of motion sickness and abnormal gastric myoelectric activity.

  20. 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

  1. Visualizing electromagnetic fields in laser-produced counter-streaming plasma experiments for collisionless shock laboratory astrophysics

    SciTech Connect

    Kugland, N. L.; Ross, J. S.; Glenzer, S. H.; Huntington, C.; Martinez, D.; Plechaty, C.; Remington, B. A.; Ryutov, D. D.; Park, H.-S.; Chang, P.-Y.; Fiksel, G.; Froula, D. H.; Drake, R. P.; Grosskopf, M.; Kuranz, C.; Gregori, G.; Meinecke, J.; Reville, B.; Koenig, M.; Pelka, A.; and others

    2013-05-15

    Collisionless shocks are often observed in fast-moving astrophysical plasmas, formed by non-classical viscosity that is believed to originate from collective electromagnetic fields driven by kinetic plasma instabilities. However, the development of small-scale plasma processes into large-scale structures, such as a collisionless shock, is not well understood. It is also unknown to what extent collisionless shocks contain macroscopic fields with a long coherence length. For these reasons, it is valuable to explore collisionless shock formation, including the growth and self-organization of fields, in laboratory plasmas. The experimental results presented here show at a glance with proton imaging how macroscopic fields can emerge from a system of supersonic counter-streaming plasmas produced at the OMEGA EP laser. Interpretation of these results, plans for additional measurements, and the difficulty of achieving truly collisionless conditions are discussed. Future experiments at the National Ignition Facility are expected to create fully formed collisionless shocks in plasmas with no pre-imposed magnetic field.

  2. Visualizing electromagnetic fields in laser-produced counter-streaming plasma experiments for collisionless shock laboratory astrophysicsa)

    NASA Astrophysics Data System (ADS)

    Kugland, N. L.; Ross, J. S.; Chang, P.-Y.; Drake, R. P.; Fiksel, G.; Froula, D. H.; Glenzer, S. H.; Gregori, G.; Grosskopf, M.; Huntington, C.; Koenig, M.; Kuramitsu, Y.; Kuranz, C.; Levy, M. C.; Liang, E.; Martinez, D.; Meinecke, J.; Miniati, F.; Morita, T.; Pelka, A.; Plechaty, C.; Presura, R.; Ravasio, A.; Remington, B. A.; Reville, B.; Ryutov, D. D.; Sakawa, Y.; Spitkovsky, A.; Takabe, H.; Park, H.-S.

    2013-05-01

    Collisionless shocks are often observed in fast-moving astrophysical plasmas, formed by non-classical viscosity that is believed to originate from collective electromagnetic fields driven by kinetic plasma instabilities. However, the development of small-scale plasma processes into large-scale structures, such as a collisionless shock, is not well understood. It is also unknown to what extent collisionless shocks contain macroscopic fields with a long coherence length. For these reasons, it is valuable to explore collisionless shock formation, including the growth and self-organization of fields, in laboratory plasmas. The experimental results presented here show at a glance with proton imaging how macroscopic fields can emerge from a system of supersonic counter-streaming plasmas produced at the OMEGA EP laser. Interpretation of these results, plans for additional measurements, and the difficulty of achieving truly collisionless conditions are discussed. Future experiments at the National Ignition Facility are expected to create fully formed collisionless shocks in plasmas with no pre-imposed magnetic field.

  3. Abnormal Activity Detection Using Pyroelectric Infrared Sensors

    PubMed Central

    Luo, Xiaomu; Tan, Huoyuan; Guan, Qiuju; Liu, Tong; Zhuo, Hankz Hankui; Shen, Baihua

    2016-01-01

    Healthy aging is one of the most important social issues. In this paper, we propose a method for abnormal activity detection without any manual labeling of the training samples. By leveraging the Field of View (FOV) modulation, the spatio-temporal characteristic of human activity is encoded into low-dimension data stream generated by the ceiling-mounted Pyroelectric Infrared (PIR) sensors. The similarity between normal training samples are measured based on Kullback-Leibler (KL) divergence of each pair of them. The natural clustering of normal activities is discovered through a self-tuning spectral clustering algorithm with unsupervised model selection on the eigenvectors of a modified similarity matrix. Hidden Markov Models (HMMs) are employed to model each cluster of normal activities and form feature vectors. One-Class Support Vector Machines (OSVMs) are used to profile the normal activities and detect abnormal activities. To validate the efficacy of our method, we conducted experiments in real indoor environments. The encouraging results show that our method is able to detect abnormal activities given only the normal training samples, which aims to avoid the laborious and inconsistent data labeling process. PMID:27271632

  4. Abnormal Activity Detection Using Pyroelectric Infrared Sensors.

    PubMed

    Luo, Xiaomu; Tan, Huoyuan; Guan, Qiuju; Liu, Tong; Zhuo, Hankz Hankui; Shen, Baihua

    2016-01-01

    Healthy aging is one of the most important social issues. In this paper, we propose a method for abnormal activity detection without any manual labeling of the training samples. By leveraging the Field of View (FOV) modulation, the spatio-temporal characteristic of human activity is encoded into low-dimension data stream generated by the ceiling-mounted Pyroelectric Infrared (PIR) sensors. The similarity between normal training samples are measured based on Kullback-Leibler (KL) divergence of each pair of them. The natural clustering of normal activities is discovered through a self-tuning spectral clustering algorithm with unsupervised model selection on the eigenvectors of a modified similarity matrix. Hidden Markov Models (HMMs) are employed to model each cluster of normal activities and form feature vectors. One-Class Support Vector Machines (OSVMs) are used to profile the normal activities and detect abnormal activities. To validate the efficacy of our method, we conducted experiments in real indoor environments. The encouraging results show that our method is able to detect abnormal activities given only the normal training samples, which aims to avoid the laborious and inconsistent data labeling process. PMID:27271632

  5. Molecular abnormalities in Ewing's sarcoma.

    PubMed

    Burchill, Susan Ann

    2008-10-01

    Ewing's sarcoma is one of the few solid tumors for which the underlying molecular genetic abnormality has been described: rearrangement of the EWS gene on chromosome 22q12 with an ETS gene family member. These translocations define the Ewing's sarcoma family of tumors (ESFT) and provide a valuable tool for their accurate and unequivocal diagnosis. They also represent ideal targets for the development of tumor-specific therapeutics. Although secondary abnormalities occur in over 80% of primary ESFT the clinical utility of these is currently unclear. However, abnormalities in genes that regulate the G(1)/S checkpoint are frequently described and may be important in predicting outcome and response. Increased understanding of the molecular events that arise in ESFT and their role in the development and maintenance of the malignant phenotype will inform the improved stratification of patients for therapy and identify targets and pathways for the design of more effective cancer therapeutics. PMID:18925858

  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. Visual Scripting.

    ERIC Educational Resources Information Center

    Halas, John

    Visual scripting is the coordination of words with pictures in sequence. This book presents the methods and viewpoints on visual scripting of fourteen film makers, from nine countries, who are involved in animated cinema; it contains concise examples of how a storybook and preproduction script can be prepared in visual terms; and it includes a…

  8. 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

    2015-01-01

    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

  9. 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

  10. [Emotion Disorders and Abnormal Perspiration].

    PubMed

    Umeda, Satoshi

    2016-08-01

    This article reviewed the relationship between emotional disorders and abnormal perspiration. First, I focused on local brain areas related to emotional processing, and summarized the functions of the emotional network involving those local areas. Functional disorders followed by the damage in the amygdala, orbitofrontal cortex, and insular cortex were reviewed, including related abnormal perspiration. I then addressed the mechanisms of how autonomic disorders influence emotional processing. Finally, possible future directions for integrated understanding of the connection between neural activities and bodily reactions were discussed. PMID:27503817

  11. Ultrasonographic assessment of abnormal pregnancy.

    PubMed

    England, G C

    1998-07-01

    Ultrasonographic imaging is widely used in small animal practice for the diagnosis of pregnancy and the determination of fetal number. Ultrasonography can also be used to monitor abnormal pregnancies, for example, conceptuses that are poorly developed for their gestational age (and therefore are likely to fail), and pregnancies in which there is embryonic resorption or fetal abortion. An ultrasound examination may reveal fetal abnormalities and therefore alter the management of the pregnant bitch or queen prior to parturition. There are, however, a number of ultrasonographic features of normal pregnancies that may mimic disease, and these must be recognized. PMID:9698618

  12. 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…

  13. N1 enhancement in synesthesia during visual and audio–visual perception in semantic cross-modal conflict situations: an ERP study

    PubMed Central

    Sinke, Christopher; Neufeld, Janina; Wiswede, Daniel; Emrich, Hinderk M.; Bleich, Stefan; Münte, Thomas F.; Szycik, Gregor R.

    2014-01-01

    Synesthesia entails a special kind of sensory perception, where stimulation in one sensory modality leads to an internally generated perceptual experience of another, not stimulated sensory modality. This phenomenon can be viewed as an abnormal multisensory integration process as here the synesthetic percept is aberrantly fused with the stimulated modality. Indeed, recent synesthesia research has focused on multimodal processing even outside of the specific synesthesia-inducing context and has revealed changed multimodal integration, thus suggesting perceptual alterations at a global level. Here, we focused on audio–visual processing in synesthesia using a semantic classification task in combination with visually or auditory–visually presented animated and in animated objects in an audio–visual congruent and incongruent manner. Fourteen subjects with auditory-visual and/or grapheme-color synesthesia and 14 control subjects participated in the experiment. During presentation of the stimuli, event-related potentials were recorded from 32 electrodes. The analysis of reaction times and error rates revealed no group differences with best performance for audio-visually congruent stimulation indicating the well-known multimodal facilitation effect. We found enhanced amplitude of the N1 component over occipital electrode sites for synesthetes compared to controls. The differences occurred irrespective of the experimental condition and therefore suggest a global influence on early sensory processing in synesthetes. PMID:24523689

  14. Visual Imagery without Visual Perception?

    ERIC Educational Resources Information Center

    Bertolo, Helder

    2005-01-01

    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…

  15. Extracellular Matrix Abnormalities in Schizophrenia

    PubMed Central

    Berretta, Sabina

    2011-01-01

    Emerging evidence points to the involvement of the brain extracellular matrix (ECM) in the pathophysiology of schizophrenia (SZ). Abnormalities affecting several ECM components, including Reelin and chondroitin sulfate proteoglycans (CSPGs), have been described in subjects with this disease. Solid evidence supports the involvement of Reelin, an ECM glycoprotein involved in corticogenesis, synaptic functions and glutamate NMDA receptor regulation, expressed prevalently in distinct populations of GABAergic neurons, which secrete it into the ECM. Marked changes of Reelin expression in SZ have typically been reported in association with GABA-related abnormalities in subjects with SZ and bipolar disorder. Recent findings from our group point to substantial abnormalities affecting CSPGs, a main ECM component, in the amygdala and entorhinal cortex of subjects with schizophrenia, but not bipolar disorder. Striking increases of glial cells expressing CSPGs were accompanied by reductions of perineuronal nets, CSPG- and Reelin-enriched ECM aggregates enveloping distinct neuronal populations. CSPGs developmental and adult functions, including neuronal migration, axon guidance, synaptic and neurotransmission regulation are highly relevant to the pathophysiology of SZ. Together with reports of anomalies affecting several other ECM components, these findings point to the ECM as a key component of the pathology of SZ. We propose that ECM abnormalities may contribute to several aspects of the pathophysiology of this disease, including disrupted connectivity and neuronal migration, synaptic anomalies and altered GABAergic, glutamatergic and dopaminergic neurotransmission. PMID:21856318

  16. FAITH Water Channel Flow Visualization

    NASA Video Gallery

    Water channel flow visualization experiments are performed on a three dimensional model of a small hill. This experiment was part of a series of measurements of the complex fluid flow around the hi...

  17. 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…

  18. Visual Recognition Memory across Contexts

    ERIC Educational Resources Information Center

    Jones, Emily J. H.; Pascalis, Olivier; Eacott, Madeline J.; Herbert, Jane S.

    2011-01-01

    In two experiments, we investigated the development of representational flexibility in visual recognition memory during infancy using the Visual Paired Comparison (VPC) task. In Experiment 1, 6- and 9-month-old infants exhibited recognition when familiarization and test occurred in the same room, but showed no evidence of recognition when…

  19. Visual Cortex Plasticity Following Peripheral Damage To The Visual System: fMRI Evidence.

    PubMed

    Lemos, João; Pereira, Daniela; Castelo-Branco, Miguel

    2016-10-01

    Over the last two decades, functional magnetic resonance imaging (fMRI) has become a powerful research method to investigate cortical visual plasticity. Abnormal fMRI response patterns have been occasionally detected in the visually deprived cortex of patients with bilateral retinal diseases. Controversy remains whether these observations indicate structural reorganization of the visual cortex or unmasking of previously silent cortico-cortical connections. In optic nerve diseases, there is weak evidence showing that early visual cortex seems to lack reorganization, while higher-order visual areas undergo plastic changes which may contribute to optimise visual function. There is however accumulating imaging evidence demonstrating trans-synaptic degeneration of the visual cortex in patients with disease of the anterior visual pathways. This may preclude the use of restorative treatments in these patients. Here, we review and update the body of fMRI evidence on visual cortical plasticity. PMID:27542799

  20. Identification of abnormal operating conditions and intelligent decision system

    NASA Astrophysics Data System (ADS)

    Li, Xiuliang; Jiang, Junjie; Su, Hongye; Chu, Jian

    2011-12-01

    In earth pressure balance (EPB) shield construction, the "plastic flow state" is difficult to form using the soil dug in the capsule because it can cause three abnormal operating conditions, including occlusion, caking in the capsule, and spewing at the outlet of the dump device. These abnormal operating conditions can, in turn, trigger failure in tunneling, cutter-device damage, and even catastrophic incidents, such as ground settlement. This present paper effectively integrates the mechanism of abnormal operating conditions and knowledge of soil conditioning, and establishes a uniform model of identifying abnormal conditions and intelligent decision support system based on the belief rule-base system. The model maximizes knowledge in improving the soil, construction experience, and data to optimize the model online. Finally, a numerical simulation with specific construction data is presented to illustrate the effectiveness of the algorithm.

  1. 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)

  2. GLIAL ABNORMALITIES IN MOOD DISORDERS

    PubMed Central

    Öngür, Dost; Bechtholt, Anita J.; Carlezon, William A.; Cohen, Bruce M.

    2015-01-01

    Multiple lines of evidence indicate that mood disorders are associated with abnormalities in the brain's cellular composition, especially in glial cells. Considered inert support cells in the past, glial cells are now known to be important for brain function. Treatments for mood disorders enhance glial cell proliferation, and experimental stimulation of cell growth has antidepressant effects in animal models of mood disorders. These findings suggest that the proliferation and survival of glial cells may be important in the pathogenesis of mood disorders and may be possible targets for the development of new treatments. In this chapter, we will review the evidence for glial abnormalities in mood disorders. We will discuss glial cell biology and evidence from postmortem studies of mood disorders. This is not carry out a comprehensive review; rather we selectively discuss existing evidence in building an argument for the role of glial cells in mood disorders. PMID:25377605

  3. Spreading photoparoxysmal EEG response is associated with an abnormal cortical excitability pattern.

    PubMed

    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 with occipital spikes only) or spread to anterior non-visual cortical regions (i.e. PPR with propagation). The mechanisms underlying the PPR and causing its spread remain to be clarified. In unmedicated PPR-positive individuals and PPR-negative control participants without any history of previous seizures, we used focal transcranial magnetic stimulation (TMS) to investigate the excitability of the visual or primary motor cortex (M1). In the first experiment [18 healthy control subjects (i.e. without PPR in electroencephalography: 6 females, mean age 26.5 +/- 7.34 years) and 17 healthy participants with PPR (7 females, mean age 25.18 +/- 12.2 years) were studied], occipital TMS was used to elicit phosphenes or to suppress the visual perception of letter trigrams. PPR-positive individuals with propagation had lower phosphene thresholds and steeper stimulus-response curves than individuals without PPR or with occipital spikes only. Occipital TMS also induced a stronger suppression of visual perception in PPR-positive subjects with propagation relative to subjects without PPR or with occipital spikes. In the second experiment, we applied TMS over the right M1 without concurrent IPS and measured the motor threshold, the stimulus response curve, and the duration of the cortical silent period (CSP) in PPR positive individuals with propagation and in PPR-negative control participants [15 right-handed healthy subjects without PPR (3 males, mean age 17.7 +/- 3.6 years) and 14 right-handed healthy individuals showing a PPR with propagation (3 males, mean age 17.4 +/- 3.9 years)]. PPR-positive individuals showed no changes in these

  4. A new user-friendly experiment visual database system application to the gas migration test (GMT) at the Grimsel test site

    SciTech Connect

    Shimura, Tomoyuki; Asano, Hidekazu; Ando, Kenichi; Okuma, Fumiko; Yamamoto, Shuichi; Vomvoris, Stratis

    2007-07-01

    Available in abstract form only. Full text of publication follows: Long-term integrated field investigations combine information from different groups (laboratory, modeling, experimental) often working in different locations and on different time scales. The results of these different groups are evaluated and integrated for decision making during the experiment execution, but at the end of the experiment a huge database exists, which may be difficult to use at a later stage - for example, for further modeling, benchmarking etc. How can one preserve the information obtained and present it in a transparent and user-friendly manner? A new visual database system developed is presented and its application to the 'Gas Migration in-situ Test (GMT)' is described. The GMT project has been conducted to assess the gas migration (for example from TRU waste) through the engineered barrier system and the adjacent geosphere. The experiment was initiated in 1997 under the auspices of RWMC and with primary funding by the Japanese Ministry of Economy, Trade and Industry. The project consists of a large-scale in-situ test, laboratory tests and numerical modeling. The in-situ test has been performed at the Grimsel Test Site (GTS) in Switzerland operated by NAGRA (National cooperative for the disposal of radioactive waste, Switzerland). Laboratory tests have been performed in facilities in Japan, Germany, Spain and Switzerland. Finally, the modeling activities, performed within the modeling group, have included teams from the US, Spain, France, Japan, Germany and Switzerland with support from organizations BGR, ENRESA, ANDRA, and RWMC. More than 250 reports document the various data and analyses. The database developed uses a three layered framework. The first (or bottom) layer is the data storage which contains all reports, publications as well as the raw data; the second layer is a data flow diagram - from material data, generation of input data to the model and output to the end

  5. Mathematical Visualization

    ERIC Educational Resources Information Center

    Rogness, Jonathan

    2011-01-01

    Advances in computer graphics have provided mathematicians with the ability to create stunning visualizations, both to gain insight and to help demonstrate the beauty of mathematics to others. As educators these tools can be particularly important as we search for ways to work with students raised with constant visual stimulation, from video games…

  6. Visual Literacy

    ERIC Educational Resources Information Center

    Felten, Peter

    2008-01-01

    Living in an image-rich world does not mean students (or faculty and administrators) naturally possess sophisticated visual literacy skills, just as continually listening to an iPod does not teach a person to critically analyze or create music. Instead, "visual literacy involves the ability to understand, produce, and use culturally significant…

  7. Visual Literacy.

    ERIC Educational Resources Information Center

    Lamberski, Richard J.

    A series of articles examines visual literacy from the perspectives of definition, research, curriculum, and resources. Articles examining the definition of visual literacy approach it in terms of semantics, techniques, and exploratory definition areas. There are surveys of present and potential research, and a discussion of the problem of…

  8. Visual Closure.

    ERIC Educational Resources Information Center

    Groffman, Sidney

    An experimental test of visual closure based on an information-theory concept of perception was devised to test the ability to discriminate visual stimuli with reduced cues. The test is to be administered in a timed individual situation in which the subject is presented with sets of incomplete drawings of simple objects that he is required to name…

  9. Visual Thinking.

    ERIC Educational Resources Information Center

    Arnheim, Rudolf

    Based on the more general principle that all thinking (including reasoning) is basically perceptual in nature, the author proposes that visual perception is not a passive recording of stimulus material but an active concern of the mind. He delineates the task of visually distinguishing changes in size, shape, and position and points out the…

  10. 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.

  11. 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…

  12. Validation, Verification and Evaluation of Visualization Software: Position Statement

    NASA Technical Reports Server (NTRS)

    Globus, Al; Kutler, Paul (Technical Monitor)

    1998-01-01

    Visualization software needs rigorous verification in the form of much better testing, and experiments with human subjects are essential to scientifically validate and evaluate visualization techniques.

  13. Abnormal Functional Connectivity Density in Post-traumatic Stress Disorder.

    PubMed

    Zhang, Youxue; Xie, Bing; Chen, Heng; Li, Meiling; Liu, Feng; Chen, Huafu

    2016-05-01

    Post-traumatic stress disorder (PTSD) is a psychiatric disorder that occurs in individuals who have experienced life-threatening mental traumas. Previous neuroimaging studies have indicated that the pathology of PTSD may be associated with the abnormal functional integration among brain regions. In the current study, we used functional connectivity density (FCD) mapping, a novel voxel-wise data-driven approach based on graph theory, to explore aberrant FC through the resting-state functional magnetic resonance imaging of the PTSD. We calculated both short- and long-range FCD in PTSD patients and healthy controls (HCs). Compared with HCs, PTSD patients showed significantly increased long-range FCD in the left dorsolateral prefrontal cortex (DLPFC), but no abnormal short-range FCD was found in PTSD. Furthermore, seed-based FC analysis of the left DLPFC showed increased connectivity in the left superior parietal lobe and visual cortex of PTSD patients. The results suggested that PTSD patients experienced a disruption of intrinsic long-range functional connections in the fronto-parietal network and visual cortex, which are associated with attention control and visual information processing. PMID:26830769

  14. Giant axonal neuropathy: visual and oculomotor deficits.

    PubMed

    Kirkham, T H; Guitton, D; Coupland, S G

    1980-08-01

    Giant axonal neuropathy, a generalised disorder or neurofilaments, presents as a chronic, progressive peripheral neuropathy in childhood. Evidence for central nervous system involvement is demonstrated in this study of four male patients with giant axonal neuropathy who had defective visual function and abnormal ocular motility. The visual system was studied by electroretinography, which showed normal retinal function, and by visual evoked potentials, which showed disease of both optic nerves and retrochiasmal visual pathways. The ocular motility disorder, studied by electrooculography, comprised defective pursuit, inability to maintain eccentric gaze with gaze paretic and rebound nystagmus, abnormal optokinetic responses and failure of suppression of the vestibulo-ocular reflex by fixation. These findings suggested involvement by giant axonal neuropathy of the cerebellar and brain stem pathways important in the control of ocular motility. PMID:7192592

  15. Making chromosome abnormalities treatable conditions.

    PubMed

    Cody, Jannine DeMars; Hale, Daniel Esten

    2015-09-01

    Individuals affected by the classic chromosome deletion syndromes which were first identified at the beginning of the genetic age, are now positioned to benefit from genomic advances. This issue highlights five of these conditions (4p-, 5p-, 11q-, 18p-, and 18q-). It focuses on the increased in understanding of the molecular underpinnings and envisions how these can be transformed into effective treatments. While it is scientifically exciting to see the phenotypic manifestations of hemizygosity being increasingly understood at the molecular and cellular level, it is even more amazing to consider that we are now on the road to making chromosome abnormalities treatable conditions. PMID:26351122

  16. Foot abnormalities of wild birds

    USGS Publications Warehouse

    Herman, C.M.; Locke, L.N.; Clark, G.M.

    1962-01-01

    The various foot abnormalities that occur in birds, including pox, scaly-leg, bumble-foot, ergotism and freezing are reviewed. In addition, our findings at the Patuxent Wildlife Research Center include pox from dove, mockingbird, cowbird, grackle and several species of sparrows. Scaly-leg has been particularly prevalent on icterids. Bumble foot has been observed in a whistling swan and in a group of captive woodcock. Ergotism is reported from a series of captive Canada geese from North Dakota. Several drug treatments recommended by others are presented.

  17. Visual hallucinations.

    PubMed

    Collerton, Daniel; Mosimann, Urs Peter

    2010-11-01

    Understanding of visual hallucinations is developing rapidly. Single-factor explanations based on specific pathologies have given way to complex multifactor models with wide potential applicability. Clinical studies of disorders with frequent hallucinations-dementia, delirium, eye disease and psychosis-show that dysfunction within many parts of the distributed ventral object perception system is associated with a range of perceptions from simple flashes and dots to complex formed figures and landscapes. Dissociations between these simple and complex hallucinations indicate at least two hallucinatory syndromes, though exact boundaries need clarification. Neural models of hallucinations variably emphasize the importance of constraints from top down dorsolateral frontal systems, bottom up occipital systems, interconnecting tracts, and thalamic and brainstem regulatory systems. No model has yet gained general acceptance. Both qualitative (a small number of necessary and sufficient constraints) and quantitative explanations (an accumulation of many nonspecific factors) fit existing data. Variable associations of hallucinations with emotional distress and thought disorders across and within pathologies may reflect the roles of cognitive and regulatory systems outside of the purely perceptual. Functional imaging demonstrates that hallucinations and veridical perceptions occur in the same brain areas, intimating a key role for the negotiating interface between top down and bottom up processes. Thus, hallucinations occur when a perception that incorporates a hallucinatory element can provide a better match between predicted and actual sensory input than does a purely veridical experience. Translational research that integrates understandings from clinical hallucinations and basic vision science is likely to be the key to better treatments. WIREs Cogn Sci 2010 1 781-786 For further resources related to this article, please visit the WIREs website. PMID:26271777

  18. Visual impairment.

    PubMed

    Ellenberger, Carl

    2016-01-01

    This chapter can guide the use of imaging in the evaluation of common visual syndromes: transient visual disturbance, including migraine and amaurosis fugax; acute optic neuropathy complicating multiple sclerosis, neuromyelitis optica spectrum disorder, Leber hereditary optic neuropathy, and Susac syndrome; papilledema and pseudotumor cerebri syndrome; cerebral disturbances of vision, including posterior cerebral arterial occlusion, posterior reversible encephalopathy, hemianopia after anterior temporal lobe resection, posterior cortical atrophy, and conversion blindness. Finally, practical efforts in visual rehabilitation by sensory substitution for blind patients can improve their lives and disclose new information about the brain. PMID:27430448

  19. HEP visualization and video technology

    SciTech Connect

    Lebrun, P.; Swoboda, D.

    1994-12-31

    The use of scientific visualization for HEP analysis is briefly reviewed. The applications are highly interactive and very dynamical in nature. At Fermilab, E687, in collaboration with Visual Media Services, has produced a 1/2 hour video tape demonstrating the capability of SGI-EXPLORER applied to a Dalitz Analysis of Charm decay. This short contribution describes the authors experience with visualization and video technologies.

  20. Computed tomography of the abnormal thymus

    SciTech Connect

    Baron, R.L.; Lee, J.K.T.; Sagel, S.S.; Levitt, R.G.

    1982-01-01

    Computed tomography (CT) should be the imaging method of choice following plain chest radiographs when a suspected thymic abnormality requires further evaluation. Based upon a six-year experience, including the evaluation of 25 patients with thymic pathology, CT was found useful in suggesting or excluding a diagnosis of thymoma and in distinguishing thymic hyperplasis from thymoma in patients with myasthenia gravis. The thickness of the thymic lobes determined by CT was found to be a more accurate indicator of infiltrative disease (thymic hyperplasia and lymphoma) than the width. CT was helpful in differentiating benign thymic cysts from solid tumors, and in defining the extent of a thymic neoplasms. On occasion, CT may suggest the specific histologic nature of a thymic lesion.

  1. Ocular abnormalities in multi-transfused beta-thalassemia patients

    PubMed Central

    Jafari, Reza; Heydarian, Samira; Karami, Hosein; Shektaei, Mohammad Momeni; Dailami, Kiumars Noruzpour; Amiri, Ahmad Ahmadzadeh; Rezaee, Majid Reza Sheikh; Far, Asad Allah Farrokh

    2015-01-01

    Aims: The aim of this study was to assess ocular changes in thalassemia patients who have received multiple transfusions and chelate binding therapy in order to avoid iron accumulation. Settings and Design: A cross-sectional study. Subjects and Methods: A total of 54 thalassemia major patients were selected as case group, and 54 age- and sex-matched healthy subjects were regarded as a control group. Ocular examination included visual acuity, refraction testing, slit lamp examination, funduscopy, tonometry, perimetry, tear break-up time test, and color vision testing were performed for all the participants. We computed the frequency and duration of blood transfusion, the mean serum ferritin level, pretransfusion hemoglobin concentration, and type, duration, and daily dose of chelation therapy for thalassemia patients based on their records. Statistical Analysis Used: All data analysis was performed using SPSS, version 19. Results: All the thalassemic patients were asymptomatic, but abnormal ocular findings (dry eye (33.3%), cataract (10.2%), retinal pigment epithelium degeneration (16.7%), color vision deficiency (3.7%), and visual field defects (33.7%)) were seen in 68.5% of thalassemic group. The prevalence of ocular abnormalities in normal group was 19.4%, which was significantly lower than that in thalassemia patients (P = 0.000). No significant correlation was found between ocular abnormalities and mean serum ferritin level (P = 0.627) and mean hemoglobin concentration (P = 0.143). Correlation of number of blood transfusion with the presence of ocular abnormalities was found to be statistically significant (P = 0.005). Conclusions: As life expectancy for beta-thalassemia patients extends, regular ophthalmological evaluation to detect early changes in their ocular system is recommended. PMID:26632126

  2. Abnormality on Liver Function Test

    PubMed Central

    2013-01-01

    Children with abnormal liver function can often be seen in outpatient clinics or inpatients wards. Most of them have respiratory disease, or gastroenteritis by virus infection, accompanying fever. Occasionally, hepatitis by the viruses causing systemic infection may occur, and screening tests are required. In patients with jaundice, the tests for differential diagnosis and appropriate treatment are important. In the case of a child with hepatitis B virus infection vertically from a hepatitis B surface antigen positive mother, the importance of the recognition of immune clearance can't be overstressed, for the decision of time to begin treatment. Early diagnosis changes the fate of a child with Wilson disease. So, screening test for the disease should not be omitted. Non-alcoholic fatty liver disease, which is mainly discovered in obese children, is a new strong candidate triggering abnormal liver function. Muscular dystrophy is a representative disease mimicking liver dysfunction. Although muscular dystrophy is a progressive disorder, and early diagnosis can't change the fate of patients, it will be better to avoid parent's blame for delayed diagnosis. PMID:24511518

  3. Medical management of abnormal pregnancy.

    PubMed

    Ratnam, S S; Prasad, R N

    1990-06-01

    Medical termination of abnormal pregnancy requires specific techniques since some conditions make therapy more effective, e.g., missed abortion intrauterine death and molar pregnancy, and others less so, e.g. anencephalic pregnancy. In all cases it is best to terminate the pregnancy as soon as possible to reduce anguish and risks of complications such as consumptive coagulopathy. Oxytocin is not consistently effective, but intraamniotic rivanol has oxytocic properties, and prostaglandins (PGs) are effective by several routes. Surgical methods are more popular in Japan and the US. A diagnostic flow chart is included and described. For missed abortion and fetal death vacuum aspiration or dilatation and evacuation are appropriate for early pregnancy, or PGs are used for later pregnancy, unless there are medical contraindications. Anencephalic pregnancy, usually diagnoses in 2nd or 3rd trimester, is resistant to medical therapy and must often be terminated by cesarean section. Molar pregnancy can be managed with vacuum aspiration at any length of gestation, but must be completed by curettage. Intraamniotic PGs are not advised for mole or fetal death. PG analogs can be administered intramuscularly, or vaginally in gel form. Other types of abnormal pregnancy that can be managed with PGs are spina bifida, hydrocephalus, hydrops fetalis, Dandy-Walker syndrome and Down's syndrome. Tubal pregnancy can be evacuated with intratubally administered PGs under laparoscopic control, thereby preserving tubal integrity. PMID:2225605

  4. Visualizing quantitative microscopy data: History and challenges

    PubMed Central

    Sailem, Heba Z.; Cooper, Sam; Bakal, Chris

    2016-01-01

    Abstract Data visualization is a fundamental aspect of science. In the context of microscopy-based studies, visualization typically involves presentation of the images themselves. However, data visualization is challenging when microscopy experiments entail imaging of millions of cells, and complex cellular phenotypes are quantified in a high-content manner. Most well-established visualization tools are inappropriate for displaying high-content data, which has driven the development of new visualization methodology. In this review, we discuss how data has been visualized in both classical and high-content microscopy studies; as well as the advantages, and disadvantages, of different visualization methods. PMID:26906253

  5. Visualizing quantitative microscopy data: History and challenges.

    PubMed

    Sailem, Heba Z; Cooper, Sam; Bakal, Chris

    2016-01-01

    Data visualization is a fundamental aspect of science. In the context of microscopy-based studies, visualization typically involves presentation of the images themselves. However, data visualization is challenging when microscopy experiments entail imaging of millions of cells, and complex cellular phenotypes are quantified in a high-content manner. Most well-established visualization tools are inappropriate for displaying high-content data, which has driven the development of new visualization methodology. In this review, we discuss how data has been visualized in both classical and high-content microscopy studies; as well as the advantages, and disadvantages, of different visualization methods. PMID:26906253

  6. From Visuals to Words.

    ERIC Educational Resources Information Center

    Stewig, John Warren

    This speech indicates how teachers can use visual materials in classrooms to promote writing by children in primary school. Five classroom tested motivating experiences discussed are: (1) adding words to wordless picture books, (2) writing about artist's paintings, (3) writing story lines from films, (4) comparing variant editions of the same…

  7. Visual cognition

    SciTech Connect

    Pinker, S.

    1985-01-01

    This book consists of essays covering issues in visual cognition presenting experimental techniques from cognitive psychology, methods of modeling cognitive processes on computers from artificial intelligence, and methods of studying brain organization from neuropsychology. Topics considered include: parts of recognition; visual routines; upward direction; mental rotation, and discrimination of left and right turns in maps; individual differences in mental imagery, computational analysis and the neurological basis of mental imagery: componental analysis.

  8. Abnormal Grain Growth in M-252 and S-816 Alloys

    NASA Technical Reports Server (NTRS)

    Decker, R F; Rush, A I; Dano, A G; Freeman, J W

    1957-01-01

    An experimental investigation was carried out on air- and vacuum-melted M-252 and S-816 alloys to find conditions of heating and hot-working which resulted in abnormal grain growth. The experiments were mainly limited to normal conditions of heating for hot-working and heat treatment and normal temperatures of solution treatment were used to allow grain growth after susceptibility to abnormal grain growth was developed by various experimental conditions. Results indicated that small reductions of essentially strain-free metal were the basic cause of such grain growth.

  9. Visual-Motor Localizations in Normal and Subnormal Development.

    ERIC Educational Resources Information Center

    Anwar, Feriha

    1981-01-01

    Reports four experiments comparing the visual target localization performance of severely subnormal, moderately subnormal, and normal preschoolers, of like mental age, under conditions of visually guided or visually directed feedback. (SJL)

  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. Vection and induced visual motion

    NASA Astrophysics Data System (ADS)

    Howard, Ian P.

    1991-12-01

    When exposed to a large moving visual display, a person experiences illusory self motion (vection). Specialized devices were used to investigate the relation between illusory visual motion of stationary objects and illusory self motion induced by motion of a visual scene. In a first set of experiments, two distinct components of induced visual motion were measured: exocentric induced motion which causes a stationary object to appear to move with the self, and egocentric induced motion which causes an object to seem to move relative to the self. Another set of experiments was designed to reveal the extent to which vection depends on the presence of stationary objects in the field of view and to explore what types of relative motion between the moving display and the stationary objects most strongly induce vection. It was observed that when all stationary objects were removed, vection had a long latency and was very weak when it occurred. A third set of experiments was designed to reveal the extent to which illusory body tilt induced by viewing a tilted or rotating scene depends on the motion of a visual stimulus and on the geometrical features of the stimulus. The results reveal the relative contributions of visual polarity and visual motion to illusory body tilt and the extent to which visual stimuli can override conflicting stimuli arising from the otolith organs.

  12. Visual Marking Inhibits Singleton Capture

    ERIC Educational Resources Information Center

    Olivers, Christian N. L.; Humphreys, Glyn W.

    2003-01-01

    This paper is concerned with how we prioritize the selection of new objects in visual scenes. We present four experiments investigating the effects of distractor previews on visual search through new objects. Participants viewed a set of to-be-ignored nontargets, with the task being to search for a target in a second set, added to the first after…

  13. Quantized visual awareness

    PubMed Central

    Escobar, W. A.

    2013-01-01

    The proposed model holds that, at its most fundamental level, visual awareness is quantized. That is to say that visual awareness arises as individual bits of awareness through the action of neural circuits with hundreds to thousands of neurons in at least the human striate cortex. Circuits with specific topologies will reproducibly result in visual awareness that correspond to basic aspects of vision like color, motion, and depth. These quanta of awareness (qualia) are produced by the feedforward sweep that occurs through the geniculocortical pathway but are not integrated into a conscious experience until recurrent processing from centers like V4 or V5 select the appropriate qualia being produced in V1 to create a percept. The model proposed here has the potential to shift the focus of the search for visual awareness to the level of microcircuits and these likely exist across the kingdom Animalia. Thus establishing qualia as the fundamental nature of visual awareness will not only provide a deeper understanding of awareness, but also allow for a more quantitative understanding of the evolution of visual awareness throughout the animal kingdom. PMID:24319436

  14. Contrast Sensitivity versus Visual Evoked Potentials in Multiple Sclerosis

    PubMed Central

    Shandiz, Javad Heravian; Nourian, Abbas; Hossaini, Mercedeh Bahr; Moghaddam, Hadi Ostadi; yekta, Abbas-Ali; Sharifzadeh, Laleh; Marouzi, Parviz

    2010-01-01

    Purpose To compare the Cambridge contrast sensitivity (CS) test and visual evoked potentials (VEP) in detecting visual impairment in a population of visually symptomatic and asymptomatic patients affected by clinically definite multiple sclerosis (MS). Methods Fifty patients (100 eyes) presenting with MS and 25 healthy subjects (50 eyes) with normal corrected visual acuity were included in this study. CS was determined using the Cambridge Low Contrast Grating test and VEP was obtained in all eyes. Findings were evaluated in two age strata of 10–29 and 30–49 years. Results Of the 42 eyes in the 10–29 year age group, CS was abnormal in 22 (52%), VEP was also abnormal in 22 (52%), but only 12 eyes (28%) had visual symptoms. Of the 58 eyes in the 30–49 year group, CS was abnormal in 7 (12%), VEP was abnormal in 34 (58%), while only 11 eyes were symptomatic. No single test could detect all of the abnormal eyes. Conclusion The Cambridge Low Contrast Grating test is useful for detection of clinical and subclinical visual dysfunction especially in young patients with multiple sclerosis. Nevertheless, only a combination of CS and VEP tests can detect most cases of visual dysfunction associated with MS. PMID:22737353

  15. Visual function and perinatal focal cerebral infarction.

    PubMed Central

    Mercuri, E; Atkinson, J; Braddick, O; Anker, S; Nokes, L; Cowan, F; Rutherford, M; Pennock, J; Dubowitz, L

    1996-01-01

    AIMS: To evaluate the visual function of infants with perinatal cerebral infarction in whom the site and size of the lesion has been determined using magnetic resonance imaging (MRI). METHODS: Twelve infants with cerebral infarction on MRI were studied with a battery of tests specifically designed to evaluate visual function in infancy. This included tests: for visual attention (fixation shifts); of cerebral asymmetry (optokinetic nystagmus, visual fields); for assessment of acuity (forced choice preferential looking); and neurophysiological measures of vision (phase reversal and orientation reversal visual evoked potential). RESULTS: A considerable incidence of abnormalities on at least one of the tests for visual function used was observed. The presence or severity of visual abnormalities could not always be predicted by the site and extent of the lesion seen on imaging. CONCLUSIONS: Early focal lesions affecting the visual pathway can, to some extent, be compensated for by the immature developing brain. These data suggest that all the infants presenting with focal lesions need to be investigated with a detailed assessment of various aspects of vision. Images PMID:8949687

  16. 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

  17. Spent fuel behavior under abnormal thermal transients during dry storage

    SciTech Connect

    Stahl, D.; Landow, M.P.; Burian, R.J.; Pasupathi, V.

    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 was 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.

  18. Adults with Chromosome 18 Abnormalities.

    PubMed

    Soileau, Bridgette; Hasi, Minire; Sebold, Courtney; Hill, Annice; O'Donnell, Louise; Hale, Daniel E; Cody, Jannine D

    2015-08-01

    The identification of an underlying chromosome abnormality frequently marks the endpoint of a diagnostic odyssey. However, families are frequently left with more questions than answers as they consider their child's future. In the case of rare chromosome conditions, a lack of longitudinal data often makes it difficult to provide anticipatory guidance to these families. The objective of this study is to describe the lifespan, educational attainment, living situation, and behavioral phenotype of adults with chromosome 18 abnormalities. The Chromosome 18 Clinical Research Center has enrolled 483 individuals with one of the following conditions: 18q-, 18p-, Tetrasomy 18p, and Ring 18. As a part of the ongoing longitudinal study, we collect data on living arrangements, educational level attained, and employment status as well as data on executive functioning and behavioral skills on an annual basis. Within our cohort, 28 of the 483 participants have died, the majority of whom have deletions encompassing the TCF4 gene or who have unbalanced rearrangement involving other chromosomes. Data regarding the cause of and age at death are presented. We also report on the living situation, educational attainment, and behavioral phenotype of the 151 participants over the age of 18. In general, educational level is higher for people with all these conditions than implied by the early literature, including some that received post-high school education. In addition, some individuals are able to live independently, though at this point they represent a minority of patients. Data on executive function and behavioral phenotype are also presented. Taken together, these data provide insight into the long-term outcome for individuals with a chromosome 18 condition. This information is critical in counseling families on the range of potential outcomes for their child. PMID:25403900

  19. The Statistics of Visual Representation

    NASA Technical Reports Server (NTRS)

    Jobson, Daniel J.; Rahman, Zia-Ur; Woodell, Glenn A.

    2002-01-01

    The experience of retinex image processing has prompted us to reconsider fundamental aspects of imaging and image processing. Foremost is the idea that a good visual representation requires a non-linear transformation of the recorded (approximately linear) image data. Further, this transformation appears to converge on a specific distribution. Here we investigate the connection between numerical and visual phenomena. Specifically the questions explored are: (1) Is there a well-defined consistent statistical character associated with good visual representations? (2) Does there exist an ideal visual image? And (3) what are its statistical properties?

  20. Visual outcome in children with congenital hemiplegia: correlation with MRI findings.

    PubMed

    Mercuri, E; Spanò, M; Bruccini, G; Frisone, M F; Trombetta, J C; Blandino, A; Longo, M; Guzzetta, F

    1996-08-01

    Fourteen children with congenital hemiplegia were studied with a detailed assessment of various aspects of vision (linear acuity, stereopsis, visual fields) and MRI. The aim of this study was to evaluate the effect of a congenital lesion on visual function. The results showed a very high incidence (78%) of children who had abnormal results on at least one of the visual tests. Visual abnormalities were not correlated with the clinical severity of hemiplegia or with a specific pattern of lesion on MRI. Similarly no constant association could be found between visual structures (optic radiations and primary visual cortex) and visual function. Finally, our results would suggest that all the children with congenital hemiplegia need to be investigated irrespective of the clinical severity or of the type or the extent of the lesion. This would help to identify children with minor visual abnormalities which can affect everyday life performance. PMID:8892366

  1. CMS tracker visualization tools

    NASA Astrophysics Data System (ADS)

    Mennea, M. S.; Osborne, I.; Regano, A.; Zito, G.

    2005-08-01

    This document will review the design considerations, implementations and performance of the CMS Tracker Visualization tools. In view of the great complexity of this sub-detector (more than 50 millions channels organized in 16540 modules each one of these being a complete detector), the standard CMS visualization tools (IGUANA and IGUANACMS) that provide basic 3D capabilities and integration within CMS framework, respectively, have been complemented with additional 2D graphics objects. Based on the experience acquired using this software to debug and understand both hardware and software during the construction phase, we propose possible future improvements to cope with online monitoring and event analysis during data taking.

  2. Visual Prosthesis

    PubMed Central

    Schiller, Peter H.; Tehovnik, Edward J.

    2009-01-01

    There are more than 40 million blind individuals in the world whose plight would be greatly ameliorated by creating a visual prosthetic. We begin by outlining the basic operational characteristics of the visual system as this knowledge is essential for producing a prosthetic device based on electrical stimulation through arrays of implanted electrodes. We then list a series of tenets that we believe need to be followed in this effort. Central among these is our belief that the initial research in this area, which is in its infancy, should first be carried out in animals. We suggest that implantation of area V1 holds high promise as the area is of a large volume and can therefore accommodate extensive electrode arrays. We then proceed to consider coding operations that can effectively convert visual images viewed by a camera to stimulate electrode arrays to yield visual impressions that can provide shape, motion and depth information. We advocate experimental work that mimics electrical stimulation effects non-invasively in sighted human subjects using a camera from which visual images are converted into displays on a monitor akin to those created by electrical stimulation. PMID:19065857

  3. Visual stability

    PubMed Central

    Melcher, David

    2011-01-01

    Our vision remains stable even though the movements of our eyes, head and bodies create a motion pattern on the retina. One of the most important, yet basic, feats of the visual system is to correctly determine whether this retinal motion is owing to real movement in the world or rather our own self-movement. This problem has occupied many great thinkers, such as Descartes and Helmholtz, at least since the time of Alhazen. This theme issue brings together leading researchers from animal neurophysiology, clinical neurology, psychophysics and cognitive neuroscience to summarize the state of the art in the study of visual stability. Recently, there has been significant progress in understanding the limits of visual stability in humans and in identifying many of the brain circuits involved in maintaining a stable percept of the world. Clinical studies and new experimental methods, such as transcranial magnetic stimulation, now make it possible to test the causal role of different brain regions in creating visual stability and also allow us to measure the consequences when the mechanisms of visual stability break down. PMID:21242136

  4. Inguinal Abnormalities in Male Patients with Acetabular Fractures Treated Using an Ilioinguinal Exposure

    PubMed Central

    Firoozabadi, Reza; Stafford, Paul; Routt, Milton

    2015-01-01

    Background: Surgeons performing an ilioinguinal exposure for acetabular fracture surgery need to be aware of aberrant findings such as inguinal hernias and spermatic cord lesions. The purpose of this study is to report these occurrences in a clinical series of adult males undergoing acetabular fracture fixation and a series of adult male cadavers. The secondary aim is to characterize these abnormalities to aid surgeons in detecting these abnormalities preoperatively and coordinating a surgical plan with a general surgeon. Methods: Clinical study- Retrospective review of treated acetabular fractures through an ilioinguinal approach. Incidence of inguinal canal and spermatic cord abnormalities requiring general surgery consultation were identified. Corresponding CT scans were reviewed and radiographic characteristics of the spermatic cord abnormalities and/or hernias were noted. Cadaveric study- 18 male cadavers dissected bilaterally using an ilioinguinal exposure. The inguinal canal and the contents of the spermatic cord were identified and characterized. Results: Clinical Study- 5.7% (5/87) of patients had spermatic cord lesion and/or inguinal hernia requiring general surgical intervention. Preoperative pelvic CT scan review identified abnormalities noted intraoperatively in four of the five patients. Cord lipomas visualized as enlargements of the spermatic cord with homogeneous density. Hernias visualized as enlarged spermatic cords with heterogeneous density. Cadaver Study- 31% (11/36) of cadavers studied had spermatic cord and/or inguinal canal abnormalities. Average cord diameter in those with abnormalities was 24.9 mm (15-28) compared to 16 mm (11-22) in normal cords, which was statistically significant. Discussion: The clinical and cadaveric findings emphasize the importance of understanding inguinal abnormalities and the value of detecting them preoperatively. The preoperative pelvic CT scans were highly sensitive in detecting inguinal abnormalities. PMID

  5. Breathing abnormalities in sleep in achondroplasia.

    PubMed Central

    Waters, K A; Everett, F; Sillence, D; Fagan, E; Sullivan, C E

    1993-01-01

    Overnight sleep studies were performed in 20 subjects with achondroplasia to document further the respiratory abnormalities present in this group. Somatosensory evoked potentials (SEPs) were recorded in 19 of the subjects to screen for the presence of brainstem abnormalities, which are one of the potential aetiological mechanisms. Fifteen children aged 1 to 14 years, and five young adults, aged 20 to 31 years were included. All had upper airway obstruction and 15 (75%) had a pathological apnoea index (greater than five per hour). Other sleep associated respiratory abnormalities, including partial obstruction, central apnoea, and abnormal electromyographic activity of accessory muscles of respiration, also showed a high prevalence. SEPs were abnormal in eight (42%), but there was no correlation between abnormal SEPs and apnoea during sleep, either qualitatively or quantitatively. A high prevalence of both sleep related respiratory abnormalities and abnormal SEPs in young subjects with achondroplasia was demonstrated. However, the sleep related respiratory abnormalities do not always result in significant blood gas disturbances or correlate with abnormal SEPs in this group. PMID:8215519

  6. Assessing Attainment of Competency and Program Characteristics of a Distance Preparation Program for Teachers of Students with Visual Impairments: One University's Experience

    ERIC Educational Resources Information Center

    Bickford, James O.

    2006-01-01

    As distance education becomes a more common practice in teacher preparation, it is critical that students completing these programs be held to the same standards as students completing traditional university-based programs. The author examined the achievements of students in a preparation program for teachers of children with visual impairments in…

  7. The Role of the WHO ICF as a Framework to Interpret Barriers and to Inclusion: Visually Impaired People's Views and Experiences of Personal Computers

    ERIC Educational Resources Information Center

    Douglas, Graeme; Corcoran, Christine; Pavey, Sue

    2007-01-01

    This article describes how the World Health Organisation's International Classification of Functioning, Disability, and Health (ICF), 2001, was used as a framework for the design of the interview schedule used in the Network 1000 project. It is argued that the ICF offers a vocabulary to enable visually impaired participants to describe their lives…

  8. Getting in and Getting On? The Experiences of Young People with Visual Impairments and Hearing Impairments in Third-Level Education

    ERIC Educational Resources Information Center

    Byrne, Bronagh

    2014-01-01

    Young disabled people continue to be under-represented throughout further and higher education settings. Drawing on Pierre Bourdieu's social theory of habitus, capital and field, this paper explores the practices of domination and oppression that have made it difficult for young people with visual impairments and hearing impairments to…

  9. 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…

  10. 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. PMID:25961587

  11. LogViewer: A Software Tool to Visualize Quality Control Parameters to Optimize Proteomics Experiments using Orbitrap and LTQ-FT Mass Spectrometers

    PubMed Central

    Sweredoski, Michael J.; Smith, Geoffrey T.; Kalli, Anastasia; Graham, Robert L. J.; Hess, Sonja

    2011-01-01

    Visualization tools that allow both optimization of instrument's parameters for data acquisition and specific quality control (QC) for a given sample prior to time-consuming database searches have been scarce until recently and are currently still not freely available. To address this need, we have developed the visualization tool LogViewer, which uses diagnostic data from the RAW files of the Thermo Orbitrap and linear trap quadrupole-Fourier transform (LTQ-FT) mass spectrometers to monitor relevant metrics. To summarize and visualize the performance on our test samples, log files from RawXtract are imported and displayed. LogViewer is a visualization tool that allows a specific and fast QC for a given sample without time-consuming database searches. QC metrics displayed include: mass spectrometry (MS) ion-injection time histograms, MS ion-injection time versus retention time, MS2 ion-injection time histograms, MS2 ion-injection time versus retention time, dependent scan histograms, charge-state histograms, mass-to-charge ratio (M/Z) distributions, M/Z histograms, mass histograms, mass distribution, summary, repeat analyses, Raw MS, and Raw MS2. Systematically optimizing all metrics allowed us to increase our protein identification rates from 600 proteins to routinely determine up to 1400 proteins in any 160-min analysis of a complex mixture (e.g., yeast lysate) at a false discovery rate of <1%. Visualization tools, such as LogViewer, make QC of complex liquid chromotography (LC)-MS and LC-MS/MS data and optimization of the instrument's parameters accessible to users. PMID:22131886

  12. 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…

  13. Executive function abnormalities in pathological gamblers

    PubMed Central

    2008-01-01

    Background Pathological gambling (PG) is an impulse control disorder characterized by persistent and maladaptive gambling behaviors with disruptive consequences for familial, occupational and social functions. The pathophysiology of PG is still unclear, but it is hypothesized that it might include environmental factors coupled with a genetic vulnerability and dysfunctions of different neurotransmitters and selected brain areas. Our study aimed to evaluate a group of patients suffering from PG by means of some neuropsychological tests in order to explore the brain areas related to the disorder. Methods Twenty outpatients (15 men, 5 women), with a diagnosis of PG according to DSM-IV criteria, were included in the study and evaluated with a battery of neuropsychological tests: the Wisconsin Card Sorting Test (WCST), the Wechsler Memory Scale revised (WMS-R) and the Verbal Associative Fluency Test (FAS). The results obtained in the patients were compared with normative values of matched healthy control subjects. Results The PG patients showed alterations at the WCST only, in particular they had a great difficulty in finding alternative methods of problem-solving and showed a decrease, rather than an increase, in efficiency, as they progressed through the consecutive phases of the test. The mean scores of the other tests were within the normal range. Conclusion Our findings showed that patients affected by PG, in spite of normal intellectual, linguistic and visual-spatial abilities, had abnormalities emerging from the WCST, in particular they could not learn from their mistakes and look for alternative solutions. Our results would seem to confirm an altered functioning of the prefrontal areas which might provoke a sort of cognitive "rigidity" that might predispose to the development of impulsive and/or compulsive behaviors, such as those typical of PG. PMID:18371193

  14. The Temporal Dynamics of Visual Processing in Multiple Sclerosis.

    PubMed

    Lopes Costa, Silvana; Gonçalves, Oscar F; DeLuca, John; Chiaravalloti, Nancy; Chakravarthi, Ramakrishna; Almeida, Jorge

    2016-01-01

    Although the integrity of the visual system is often affected in multiple sclerosis (MS), the potential relationship between the temporal dynamics of visual processing and performance on neuropsychological tests assessing processing speed (PS) remains relatively unexplored. Here, we test if a PS deficit is related to abnormalities within the visual system, rather than impaired higher-level cognitive function. Two groups of participants with MS (1 group with PS deficits and another without) and a healthy control group, matched for age and education, were included. To explore the temporal dynamics of visual processing, we used 2 psychophysical paradigms: attention enhancement/prioritization and rapid serial visual presentation. Visual PS deficits were associated with a decreased capability to detect visual stimuli and a higher limitation in visual temporal-processing capacity. These results suggest that a latent sensorial temporal limitation of the visual system is significantly associated to PS deficits in MS. PMID:26508328

  15. Transient uniocular visual loss on deviation of the eye in association with intraorbital tumours.

    PubMed

    Bradbury, P G; Levy, I S; McDonald, W I

    1987-05-01

    Five patients with unilateral orbital tumours are described in whom transient loss of vision occurred on deviation of the affected eye from the primary position. Other presenting features were diplopia, proptosis, poor visual acuity, visual field defects, pupillary abnormalities, fundal changes and altered colour vision. Abnormalities on fluorescein angiography suggest that the visual loss is due to transient ischaemia. Temporary uniocular loss of vision on eye movement may be an early sign of an intra-orbital mass. PMID:3035104

  16. Transient uniocular visual loss on deviation of the eye in association with intraorbital tumours.

    PubMed Central

    Bradbury, P G; Levy, I S; McDonald, W I

    1987-01-01

    Five patients with unilateral orbital tumours are described in whom transient loss of vision occurred on deviation of the affected eye from the primary position. Other presenting features were diplopia, proptosis, poor visual acuity, visual field defects, pupillary abnormalities, fundal changes and altered colour vision. Abnormalities on fluorescein angiography suggest that the visual loss is due to transient ischaemia. Temporary uniocular loss of vision on eye movement may be an early sign of an intra-orbital mass. Images PMID:3035104

  17. 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.

  18. Visual evoked potentials in infants and children.

    PubMed

    Taylor, M J; McCulloch, D L

    1992-07-01

    Visual evoked potential (VEP) studies are of great value in a wide variety of pediatric patients, including those with disorders of the sensory visual pathway and those at risk for visual pathway damage. VEPs are simple, non-invasive, and are particularly appropriate for infants and young children who cannot communicate visual symptoms or cooperate for standard vision assessment. VEPs in pediatric patients have the following main purposes: (1) detecting lesions causing dysfunction of the sensory visual pathways (the VEP is a sensitive indicator of subclinical lesions and can be used to differentiate visual impairment from visual inattention in young infants); (2) confirming functional loss when disorders of the visual system are present; (3) quantifying visual impairment in patients with known visual disorders, accomplished either empirically by noting the severity of the VEP abnormality to flash and pattern stimuli or by visual acuity estimation studies (early quantification of vision loss allows referral to early intervention programs, which can ameliorate the long-term consequences of the disability); (4) monitoring patients who are at risk for visual complications either from diseases (such as hydrocephalus or neurofibromatosis) or as a complication of therapeutic intervention (e.g., neurosurgery, chemotherapy) to help detect and avoid long-term sequelae of such therapies on the developing nervous system; (5) establishing prognosis for visual and systemic recovery based on flash VEPs for specific pediatric disorders including perinatal asphyxia in full-term neonates, acute-onset cortical blindness, and, to a fair extent, in comatose children; and (6) in some cases, contributing to the differential diagnosis. Abnormalities of flash and/or pattern VEPs are generally nonspecific to the type of exact location of the lesion, except in distinguishing prefrom postchiasmal lesions. However, in certain conditions, such as the hereditary ataxias of childhood, VEP

  19. Visualizing inequality

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2016-07-01

    The study of socioeconomic inequality is of substantial importance, scientific and general alike. The graphic visualization of inequality is commonly conveyed by Lorenz curves. While Lorenz curves are a highly effective statistical tool for quantifying the distribution of wealth in human societies, they are less effective a tool for the visual depiction of socioeconomic inequality. This paper introduces an alternative to Lorenz curves-the hill curves. On the one hand, the hill curves are a potent scientific tool: they provide detailed scans of the rich-poor gaps in human societies under consideration, and are capable of accommodating infinitely many degrees of freedom. On the other hand, the hill curves are a powerful infographic tool: they visualize inequality in a most vivid and tangible way, with no quantitative skills that are required in order to grasp the visualization. The application of hill curves extends far beyond socioeconomic inequality. Indeed, the hill curves are highly effective 'hyperspectral' measures of statistical variability that are applicable in the context of size distributions at large. This paper establishes the notion of hill curves, analyzes them, and describes their application in the context of general size distributions.

  20. Biochemical abnormalities in Pearson syndrome.

    PubMed

    Crippa, Beatrice Letizia; Leon, Eyby; Calhoun, Amy; Lowichik, Amy; Pasquali, Marzia; Longo, Nicola

    2015-03-01

    Pearson marrow-pancreas syndrome is a multisystem mitochondrial disorder characterized by bone marrow failure and pancreatic insufficiency. Children who survive the severe bone marrow dysfunction in childhood develop Kearns-Sayre syndrome later in life. Here we report on four new cases with this condition and define their biochemical abnormalities. Three out of four patients presented with failure to thrive, with most of them having normal development and head size. All patients had evidence of bone marrow involvement that spontaneously improved in three out of four patients. Unique findings in our patients were acute pancreatitis (one out of four), renal Fanconi syndrome (present in all patients, but symptomatic only in one), and an unusual organic aciduria with 3-hydroxyisobutyric aciduria in one patient. Biochemical analysis indicated low levels of plasma citrulline and arginine, despite low-normal ammonia levels. Regression analysis indicated a significant correlation between each intermediate of the urea cycle and the next, except between ornithine and citrulline. This suggested that the reaction catalyzed by ornithine transcarbamylase (that converts ornithine to citrulline) might not be very efficient in patients with Pearson syndrome. In view of low-normal ammonia levels, we hypothesize that ammonia and carbamylphosphate could be diverted from the urea cycle to the synthesis of nucleotides in patients with Pearson syndrome and possibly other mitochondrial disorders. PMID:25691415

  1. Semen abnormalities with SSRI antidepressants.

    PubMed

    2015-01-01

    Despite decades of widespread use, the adverse effect profile of "selective" serotonin reuptake inhibitor (SSRI) antidepressants has still not been fully elucidated. Studies in male animals have shown delayed sexual development and reduced fertility. Three prospective cohort studies conducted in over one hundred patients exposed to an SSRI for periods ranging from 5 weeks to 24 months found altered semen param-eters after as little as 3 months of exposure: reduced sperm concentration, reduced sperm motility, a higher percentage of abnormal spermatozoa, and increased levels of sperm DNA fragmentation. One clinical trial showed growth retardation in children considered depressed who were exposed to SSRls. SSRls may have endocrine disrupting properties. Dapoxetine is a short-acting serotonin reuptake inhibitor that is chemically related to fluoxetine and marketed in the European Union for men complaining of premature ejaculation. But the corresponding European summary of product characteristics does not mention any effects on fertility. In practice, based on the data available as of mid-2014, the effects of SSRI exposure on male fertility are unclear. However, it is a risk that should be taken into account and pointed out to male patients who would like to father a child or who are experiencing fertility problems. PMID:25729824

  2. The XXXXY Sex Chromosome Abnormality

    PubMed Central

    Barr, M. L.; Carr, D. H.; Pozsonyi, J.; Wilson, R. A.; Dunn, H. G.; Jacobson, T. S.; Miller, J. R.; Chown, B.

    1962-01-01

    The most common sex chromosome complex in sex chromatin-positive males with Klinefelter's syndrome is XXY. When the complex is XXYY or XXXY, the clinical findings do not seem to differ materially from those seen in XXY subjects, although more patients with these intersexual chromosome complements need to be studied to establish possible phenotypical expressions of the chromosomal variants. Two male children with an XXXXY sex chromosome abnormality are described. The data obtained from the study of these cases and five others described in the literature suggest that the XXXXY patient is likely to have congenital defects not usually seen in the common form of the Klinefelter syndrome. These include a triad of (1) skeletal anomalies (including radioulnar synostosis), (2) hypogenitalism (hypoplasia of penis and scrotum, incomplete descent of testes and defective prepubertal development of seminiferous tubules), and (3) greater risk of severe mental deficiency. That the conclusions are based on data from a small number of patients is emphasized, together with the need for a cytogenetic survey of a large control or unselected population. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7Fig. 8Fig. 9Fig. 10 PMID:13969480

  3. Abnormal Mitochondrial Dynamics and Neurodegenerative Diseases

    PubMed Central

    Su, Bo; Wang, Xinglong; Zheng, Ling; Perry, George; Smith, Mark A.; Zhu, Xiongwei

    2009-01-01

    Mitochondrial dysfunction is a prominent feature of various neurodegenerative diseases. A deeper understanding of the remarkably dynamic nature of mitochondria, characterized by a delicate balance of fission and fusion, has helped to fertilize a recent wave of new studies demonstrating abnormal mitochondrial dynamics in neurodegenerative diseases. This review highlights mitochondrial dysfunction and abnormal mitochondrial dynamics in Alzheimer disease, Parkinson disease, amyotrophic lateral sclerosis, and Huntington disease and discusses how these abnormal mitochondrial dynamics may contribute to mitochondrial and neuronal dysfunction. We propose that abnormal mitochondrial dynamics represents a key common pathway that mediates or amplifies mitochondrial dysfunction and neuronal dysfunction during the course of neurodegeneration. PMID:19799998

  4. Chromosomal abnormalities in child psychiatric patients.

    PubMed

    Hong, K E; Kim, J H; Moon, S Y; Oh, S K

    1999-08-01

    To determine the frequency of chromosomal abnormalities in a child psychiatric population, and to evaluate possible associations between types of abnormalities and patient's clinical characteristics, cytogenetic examination was performed on 604 patients. Demographic data, reasons for karyotyping, clinical signs, and other patient characteristics were assessed and correlated with the results from karyotyping. Chromosomal abnormalities were found in 69 patients (11.3%); these were structural in 49 cases and numerical in 20. Inversion of chromosome nine was found in 15 subjects, trisomy of chromosome 21 in 11, and fragile X in five patients. When karyotyping was performed because of intellectual impairment or multiple developmental delay, significantly more abnormalities were found than average; when performed because autistic disorder was suspected, the number of abnormalities was significantly fewer. There were no differences in clinical variables between structural and numerical abnormalities, nor among nine types of chromosomal abnormalities, except that numerical abnormalities and polymorphism were found at a later age, and that walking was more delayed and IQ was lower in patients with Down syndrome. Clinicians should be aware of the possible presence of chromosomal abnormalities in child psychiatric populations; the close collaboration with geneticists and the use of more defined guidelines for cytogenetic investigation are important. PMID:10485616

  5. Radiologic atlas of pulmonary abnormalities in children

    SciTech Connect

    Singleton, E.B.; Wagner, M.L.; Dutton, R.V.

    1988-01-01

    This book is an atlas about thoracic abnormalities in infants and children. The authors include computed tomographic, digital subtraction angiographic, ultrasonographic, and a few magnetic resonance (MR) images. They recognize and discuss how changes in the medical treatment of premature infants and the management of infection and pediatric tumors have altered some of the appearances and considerations in these diseases. Oriented toward all aspects of pulmonary abnormalities, the book starts with radiographic techniques and then discusses the normal chest, the newborn, infections, tumors, and pulmonary vascular diseases. There is comprehensive treatment of mediastinal abnormalities and a discussion of airway abnormalities.

  6. Computerised Screening for Visual Stress in Reading

    ERIC Educational Resources Information Center

    Singleton, Chris; Henderson, Lisa-Marie

    2007-01-01

    Visual stress is the experience of unpleasant visual symptoms when engaged in reading and some other visual tasks. There is currently no objective diagnostic test for this condition, which affects a substantial proportion of the population and which can disrupt development of reading skills. The reliability of subjective reports of symptoms has…

  7. Audio-Visual Aids: Historians in Blunderland.

    ERIC Educational Resources Information Center

    Decarie, Graeme

    1988-01-01

    A history professor relates his experiences producing and using audio-visual material and warns teachers not to rely on audio-visual aids for classroom presentations. Includes examples of popular audio-visual aids on Canada that communicate unintended, inaccurate, or unclear ideas. Urges teachers to exercise caution in the selection and use of…

  8. The Automaticity of Visual Statistical Learning

    ERIC Educational Resources Information Center

    Turk-Browne, Nicholas B.; Junge, Justin; Scholl, Brian J.

    2005-01-01

    The visual environment contains massive amounts of information involving the relations between objects in space and time, and recent studies of visual statistical learning (VSL) have suggested that this information can be automatically extracted by the visual system. The experiments reported in this article explore the automaticity of VSL in…

  9. Personalized visual aesthetics

    NASA Astrophysics Data System (ADS)

    Vessel, Edward A.; Stahl, Jonathan; Maurer, Natalia; Denker, Alexander; Starr, G. G.

    2014-02-01

    How is visual information linked to aesthetic experience, and what factors determine whether an individual finds a particular visual experience pleasing? We have previously shown that individuals' aesthetic responses are not determined by objective image features but are instead a function of internal, subjective factors that are shaped by a viewers' personal experience. Yet for many classes of stimuli, culturally shared semantic associations give rise to similar aesthetic taste across people. In this paper, we investigated factors that govern whether a set of observers will agree in which images are preferred, or will instead exhibit more "personalized" aesthetic preferences. In a series of experiments, observers were asked to make aesthetic judgments for different categories of visual stimuli that are commonly evaluated in an aesthetic manner (faces, natural landscapes, architecture or artwork). By measuring agreement across observers, this method was able to reveal instances of highly individualistic preferences. We found that observers showed high agreement on their preferences for images of faces and landscapes, but much lower agreement for images of artwork and architecture. In addition, we found higher agreement for heterosexual males making judgments of beautiful female faces than of beautiful male faces. These results suggest that preferences for stimulus categories that carry evolutionary significance (landscapes and faces) come to rely on similar information across individuals, whereas preferences for artifacts of human culture such as architecture and artwork, which have fewer basic-level category distinctions and reduced behavioral relevance, rely on a more personalized set of attributes.

  10. Dynamics of visually guided auditory plasticity in the optic tectum of the barn owl.

    PubMed

    Brainard, M S; Knudsen, E I

    1995-02-01

    1. In the optic tectum of normal barn owls, bimodal (auditory-visual) neurons are tuned to the values of interaural time difference (ITD) that are produced by sounds at the locations of their visual receptive fields (VRFs). The auditory tuning of tectal neurons is actively guided by visual experience during development: in the tectum of adult owls reared with an optically displaced visual field, neurons are tuned to abnormal values of ITD that are close to the values produced by sounds at the locations of their optically displaced VRFs. In this study we investigated the dynamics of this experience-dependent plasticity. 2. Owls were raised from shortly after eye-opening (14-22 days of age) with prismatic spectacles that displaced the visual field to the right or left. Starting at approximately 60 days of age, multiunit recordings were made to assess the tuning of tectal neurons to ITD presented via earphones. In the earliest recording sessions (ages 60-80 days), ITD tuning was often close to normal, even though the majority of the owls' previous experience was with an altered correspondence between ITD values and VRF locations. Subsequently, over a period of weeks, responses to the normal range of ITDs were gradually eliminated while responses to values of ITD corresponding with the optically displaced VRF were acquired. 3. At intermediate stages in this process, the ITD tuning at many sites became abnormally broad, so that responses were simultaneously present to both normal values of ITD and to values corresponding with the optically displaced VRF. At this stage the latencies and durations of newly acquired responses systematically exceeded the latencies and durations of the responses to normal values of ITD. 4. Dynamic changes in ITD tuning similar to those recorded in the optic tectum also occurred in the external nucleus of the inferior colliculus (ICX), which provides the major source of ascending auditory input to the tectum. 5. These results suggest the

  11. Snowflake Visualization

    NASA Astrophysics Data System (ADS)

    Bliven, L. F.; Kucera, P. A.; Rodriguez, P.

    2010-12-01

    NASA Snowflake Video Imagers (SVIs) enable snowflake visualization at diverse field sites. The natural variability of frozen precipitation is a complicating factor for remote sensing retrievals in high latitude regions. Particle classification is important for understanding snow/ice physics, remote sensing polarimetry, bulk radiative properties, surface emissivity, and ultimately, precipitation rates and accumulations. Yet intermittent storms, low temperatures, high winds, remote locations and complex terrain can impede us from observing falling snow in situ. SVI hardware and software have some special features. The standard camera and optics yield 8-bit gray-scale images with resolution of 0.05 x 0.1 mm, at 60 frames per second. Gray-scale images are highly desirable because they display contrast that aids particle classification. Black and white (1-bit) systems display no contrast, so there is less information to recognize particle types, which is particularly burdensome for aggregates. Data are analyzed at one-minute intervals using NASA's Precipitation Link Software that produces (a) Particle Catalogs and (b) Particle Size Distributions (PSDs). SVIs can operate nearly continuously for long periods (e.g., an entire winter season), so natural variability can be documented. Let’s summarize results from field studies this past winter and review some recent SVI enhancements. During the winter of 2009-2010, SVIs were deployed at two sites. One SVI supported weather observations during the 2010 Winter Olympics and Paralympics. It was located close to the summit (Roundhouse) of Whistler Mountain, near the town of Whistler, British Columbia, Canada. In addition, two SVIs were located at the King City Weather Radar Station (WKR) near Toronto, Ontario, Canada. Access was prohibited to the SVI on Whistler Mountain during the Olympics due to security concerns. So to meet the schedule for daily data products, we operated the SVI by remote control. We also upgraded the

  12. 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

  13. The effects of anatomical information and observer expertise on abnormality detection task

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Cavaro-Ménard, C.; Le Callet, P.; Cooper, L. H. K.; Hunault, G.; Tanguy, J.-Y.

    2011-03-01

    This paper presents a novel study investigating the influences of Magnetic Resonance (MR) image anatomical information and observer expertise on an abnormality detection task. MRI is exquisitely sensitive for detecting brain abnormalities, particularly in the evaluation of white matter diseases, e.g. multiple sclerosis (MS). For this reason, MS lesions are simulated as the target stimuli for detection in the present study. Two different image backgrounds are used in the following experiments: a) homogeneous region of white matter tissue, and b) one slice of a healthy brain MR image. One expert radiologist (more than 10 years' experience), three radiologists (less than 5 years' experience) and eight naïve observers (without any prior medical knowledge) have performed these experiments, during which they have been asked different questions dependent upon level of experience; the three radiologists and eight naïve observers were asked if they were aware of any hyper-signal, likely to represent an MS lesion, while the most experienced consultant was asked if a clinically significant sign was present. With the percentages of response "yes" displayed on the y-axis and the lesion intensity contrasts on the x-axis, psychometric function is generated from the observer' responses. Results of psychometric functions and calculated thresholds indicate that radiologists have better hyper-signal detection ability than naïve observers, which is intuitively shown by the lower simple visibility thresholds of radiologists. However, when radiologists perform a task with clinical implications, e.g. to detect a clinically significant sign, their detection thresholds are elevated. Moreover, the study indicates that for the radiologists, the simple visibility thresholds remain the same with and without the anatomical information, which reduces the threshold for the clinically significant sign detection task. Findings provide further insight into human visual system processing for this

  14. An Abnormal Psychology Community Based Interview Assignment

    ERIC Educational Resources Information Center

    White, Geoffry D.

    1977-01-01

    A course option in abnormal psychology involves students in interviewing and observing the activities of individuals in the off-campus community who are concerned with some aspect of abnormal psychology. The technique generates student interest in the field when they interview people about topics such as drug abuse, transsexualism, and abuse of…

  15. Detection of Structural Abnormalities Using Neural Nets

    NASA Technical Reports Server (NTRS)

    Zak, M.; Maccalla, A.; Daggumati, V.; Gulati, S.; Toomarian, N.

    1996-01-01

    This paper describes a feed-forward neural net approach for detection of abnormal system behavior based upon sensor data analyses. A new dynamical invariant representing structural parameters of the system is introduced in such a way that any structural abnormalities in the system behavior are detected from the corresponding changes to the invariant.

  16. Immune Abnormalities in Patients with Autism.

    ERIC Educational Resources Information Center

    Warren, Reed P.; And Others

    1986-01-01

    A study of 31 autistic patients (3-28 years old) has revealed several immune-system abnormalities, including decreased numbers of T lymphocytes and an altered ratio of helper-to-suppressor T cells. Immune-system abnormalities may be directly related to underlying biologic processes of autism or an indirect reflection of the actual pathologic…

  17. Nail abnormalities in patients with vitiligo*

    PubMed Central

    Topal, Ilteris Oguz; Gungor, Sule; Kocaturk, Ozgur Emek; Duman, Hatice; Durmuscan, Mustafa

    2016-01-01

    Background Vitiligo is an acquired pigmentary skin disorder affecting 0.1-4% of the general population. The nails may be affected in patients with an autoimmune disease such as psoriasis, and in those with alopecia areata. It has been suggested that nail abnormalities should be apparent in vitiligo patients. Objective We sought to document the frequency and clinical presentation of nail abnormalities in vitiligo patients compared to healthy volunteers. We also examined the correlations between nail abnormalities and various clinical parameters. Methods This study included 100 vitiligo patients and 100 healthy subjects. Full medical histories were collected from the subjects, who underwent thorough general and nail examinations. All nail changes were noted. In the event of clinical suspicion of a fungal infection, additional mycological investigations were performed. Results Nail abnormalities were more prevalent in the patients (78%) than in the controls (55%) (p=0.001). Longitudinal ridging was the most common finding (42%), followed by (in descending order): leukonychia, an absent lunula, onycholysis, nail bed pallor, onychomycosis, splinter hemorrhage and nail plate thinning. The frequency of longitudinal ridging was significantly higher in patients than in controls (p<0.001). Conclusions Nail abnormalities were more prevalent in vitiligo patients than in controls. Systematic examination of the nails in such patients is useful because nail abnormalities are frequent. However, the causes of such abnormalities require further study. Longitudinal ridging and leukonychia were the most common abnormalities observed in this study. PMID:27579738

  18. 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).

  19. Visualization on fish's wake

    NASA Astrophysics Data System (ADS)

    Li, Xuemin; Lu, Xiyun; Yin, Xiezhen

    2002-05-01

    In this paper an experiment on wake of Goldfish swimming unrestricted was conducted in a water tunnel. Method of color liquid was used to visualize the wake. Results show that there is reverse Karman vortex street in symmetrical plane of the wake and the Strouhal frequency of the fish is in the range 0.25-0.35. A 3D vortex ring chain model was presented.

  20. F-106 Flow Visualization

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Convair F-106B Delta Dart: As the last piloted Convair F-106 anywhere, NASA 816 saw service at Langley researching storm hazards, experimenting with an Off-Surface flow visualization system and testing a vortex flap. The Delta Dart was not turned over for target drone duty as were the vast majority of F-106s, but retired to the Virginia Air & Space Center in Hampton, Virginia.