I'll take the low road: the evolutionary underpinnings of visually triggered fear

PubMed Central

Carr, James A.

2015-01-01

Although there is general agreement that the central nucleus of the amygdala (CeA) is critical for triggering the neuroendocrine response to visual threats, there is uncertainty about the role of subcortical visual pathways in this process. Primates in general appear to depend less on subcortical visual pathways than other mammals. Yet, imaging studies continue to indicate a role for the superior colliculus and pulvinar nucleus in fear activation, despite disconnects in how these brain structures communicate not only with each other but with the amygdala. Studies in fish and amphibians suggest that the neuroendocrine response to visual threats has remained relatively unchanged for hundreds of millions of years, yet there are still significant data gaps with respect to how visual information is relayed to telencephalic areas homologous to the CeA, particularly in fish. In fact ray finned fishes may have evolved an entirely different mechanism for relaying visual information to the telencephalon. In part because they lack a pathway homologous to the lateral geniculate-striate cortex pathway of mammals, amphibians continue to be an excellent model for studying how stress hormones in turn modulate fear activating visual pathways. Glucocorticoids, melanocortin peptides, and CRF all appear to play some role in modulating sensorimotor processing in the optic tectum. These observations, coupled with data showing control of the hypothalamus-pituitary-adrenal axis by the superior colliculus, suggest a fear/stress/anxiety neuroendocrine circuit that begins with first order synapses in subcortical visual pathways. Thus, comparative studies shed light not only on how fear triggering visual pathways came to be, but how hormones released as a result of this activation modulate these pathways. PMID:26578871

Task relevance predicts gaze in videos of real moving scenes.

PubMed

Howard, Christina J; Gilchrist, Iain D; Troscianko, Tom; Behera, Ardhendu; Hogg, David C

2011-09-01

Low-level stimulus salience and task relevance together determine the human fixation priority assigned to scene locations (Fecteau and Munoz in Trends Cogn Sci 10(8):382-390, 2006). However, surprisingly little is known about the contribution of task relevance to eye movements during real-world visual search where stimuli are in constant motion and where the 'target' for the visual search is abstract and semantic in nature. Here, we investigate this issue when participants continuously search an array of four closed-circuit television (CCTV) screens for suspicious events. We recorded eye movements whilst participants watched real CCTV footage and moved a joystick to continuously indicate perceived suspiciousness. We find that when multiple areas of a display compete for attention, gaze is allocated according to relative levels of reported suspiciousness. Furthermore, this measure of task relevance accounted for twice the amount of variance in gaze likelihood as the amount of low-level visual changes over time in the video stimuli.

47 CFR 78.51 - Remote control operation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... control system shall be installed and protected in a manner designed to prevent tampering or operation by... transmissions and a carrier operated device which will give a continuous visual indication whenever the... necessary to insure proper operation. (4) The control circuits shall be so designed and installed that short...

47 CFR 78.51 - Remote control operation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... control system shall be installed and protected in a manner designed to prevent tampering or operation by... transmissions and a carrier operated device which will give a continuous visual indication whenever the... necessary to insure proper operation. (4) The control circuits shall be so designed and installed that short...

An approach to instrument qualified visual range

NASA Astrophysics Data System (ADS)

Courtade, Benoît; Bonnet, Jordan; Woodruff, Chris; Larson, Josiah; Giles, Andrew; Sonde, Nikhil; Moore, C. J.; Schimon, David; Harris, David Money; Pond, Duane; Way, Scott

2008-04-01

This paper describes a system that calculates aircraft visual range with instrumentation alone. A unique message is encoded using modified binary phase shift keying and continuously flashed at high speed by ALSF-II runway approach lights. The message is sampled at 400 frames per second by an aircraft borne high-speed camera. The encoding is designed to avoid visible flicker and minimize frame rate. Instrument qualified visual range is identified as the largest distance at which the aircraft system can acquire and verify the correct, runway-specific signal. Scaled testing indicates that if the system were implemented on one full ALSF-II fixture, instrument qualified range could be established at 5 miles in clear weather conditions.

Hazardous Continuation Backward in Time in Nonlinear Parabolic Equations, and an Experiment in Deblurring Nonlinearly Blurred Imagery

PubMed Central

Carasso, Alfred S

2013-01-01

Identifying sources of ground water pollution, and deblurring nanoscale imagery as well as astronomical galaxy images, are two important applications involving numerical computation of parabolic equations backward in time. Surprisingly, very little is known about backward continuation in nonlinear parabolic equations. In this paper, an iterative procedure originating in spectroscopy in the 1930’s, is adapted into a useful tool for solving a wide class of 2D nonlinear backward parabolic equations. In addition, previously unsuspected difficulties are uncovered that may preclude useful backward continuation in parabolic equations deviating too strongly from the linear, autonomous, self adjoint, canonical model. This paper explores backward continuation in selected 2D nonlinear equations, by creating fictitious blurred images obtained by using several sharp images as initial data in these equations, and capturing the corresponding solutions at some positive time T. Successful backward continuation from t=T to t = 0, would recover the original sharp image. Visual recognition provides meaningful evaluation of the degree of success or failure in the reconstructed solutions. Instructive examples are developed, illustrating the unexpected influence of certain types of nonlinearities. Visually and statistically indistinguishable blurred images are presented, with vastly different deblurring results. These examples indicate that how an image is nonlinearly blurred is critical, in addition to the amount of blur. The equations studied represent nonlinear generalizations of Brownian motion, and the blurred images may be interpreted as visually expressing the results of novel stochastic processes. PMID:26401430

Continued use of an interactive computer game-based visual perception learning system in children with developmental delay.

PubMed

Lin, Hsien-Cheng; Chiu, Yu-Hsien; Chen, Yenming J; Wuang, Yee-Pay; Chen, Chiu-Ping; Wang, Chih-Chung; Huang, Chien-Ling; Wu, Tang-Meng; Ho, Wen-Hsien

2017-11-01

This study developed an interactive computer game-based visual perception learning system for special education children with developmental delay. To investigate whether perceived interactivity affects continued use of the system, this study developed a theoretical model of the process in which learners decide whether to continue using an interactive computer game-based visual perception learning system. The technology acceptance model, which considers perceived ease of use, perceived usefulness, and perceived playfulness, was extended by integrating perceived interaction (i.e., learner-instructor interaction and learner-system interaction) and then analyzing the effects of these perceptions on satisfaction and continued use. Data were collected from 150 participants (rehabilitation therapists, medical paraprofessionals, and parents of children with developmental delay) recruited from a single medical center in Taiwan. Structural equation modeling and partial-least-squares techniques were used to evaluate relationships within the model. The modeling results indicated that both perceived ease of use and perceived usefulness were positively associated with both learner-instructor interaction and learner-system interaction. However, perceived playfulness only had a positive association with learner-system interaction and not with learner-instructor interaction. Moreover, satisfaction was positively affected by perceived ease of use, perceived usefulness, and perceived playfulness. Thus, satisfaction positively affects continued use of the system. The data obtained by this study can be applied by researchers, designers of computer game-based learning systems, special education workers, and medical professionals. Copyright © 2017 Elsevier B.V. All rights reserved.

Hazardous Continuation Backward in Time in Nonlinear Parabolic Equations, and an Experiment in Deblurring Nonlinearly Blurred Imagery.

PubMed

Carasso, Alfred S

2013-01-01

Identifying sources of ground water pollution, and deblurring nanoscale imagery as well as astronomical galaxy images, are two important applications involving numerical computation of parabolic equations backward in time. Surprisingly, very little is known about backward continuation in nonlinear parabolic equations. In this paper, an iterative procedure originating in spectroscopy in the 1930's, is adapted into a useful tool for solving a wide class of 2D nonlinear backward parabolic equations. In addition, previously unsuspected difficulties are uncovered that may preclude useful backward continuation in parabolic equations deviating too strongly from the linear, autonomous, self adjoint, canonical model. This paper explores backward continuation in selected 2D nonlinear equations, by creating fictitious blurred images obtained by using several sharp images as initial data in these equations, and capturing the corresponding solutions at some positive time T. Successful backward continuation from t=T to t = 0, would recover the original sharp image. Visual recognition provides meaningful evaluation of the degree of success or failure in the reconstructed solutions. Instructive examples are developed, illustrating the unexpected influence of certain types of nonlinearities. Visually and statistically indistinguishable blurred images are presented, with vastly different deblurring results. These examples indicate that how an image is nonlinearly blurred is critical, in addition to the amount of blur. The equations studied represent nonlinear generalizations of Brownian motion, and the blurred images may be interpreted as visually expressing the results of novel stochastic processes.

Blindness and Severe Visual Impairment in Pupils at Schools for the Blind in Burundi

PubMed Central

Ruhagaze, Patrick; Njuguna, Kahaki Kimani Margaret; Kandeke, Lévi; Courtright, Paul

2013-01-01

Purpose: To determine the causes of childhood blindness and severe visual impairment in pupils attending schools for the blind in Burundi in order to assist planning for services in the country. Materials and Methods: All pupils attending three schools for the blind in Burundi were examined. A modified WHO/PBL eye examination record form for children with blindness and low vision was used to record the findings. Data was analyzed for those who became blind or severely visually impaired before the age of 16 years. Results: Overall, 117 pupils who became visually impaired before 16 years of age were examined. Of these, 109 (93.2%) were blind or severely visually impaired. The major anatomical cause of blindness or severe visual impairment was cornea pathology/phthisis (23.9%), followed by lens pathology (18.3%), uveal lesions (14.7%) and optic nerve lesions (11.9%). In the majority of pupils with blindness or severe visual impairment, the underlying etiology of visual loss was unknown (74.3%). More than half of the pupils with lens related blindness had not had surgery; among those who had surgery, outcomes were generally poor. Conclusion: The causes identified indicate the importance of continuing preventive public health strategies, as well as the development of specialist pediatric ophthalmic services in the management of childhood blindness in Burundi. The geographic distribution of pupils at the schools for the blind indicates a need for community-based programs to identify and refer children in need of services. PMID:23580854

Blindness and severe visual impairment in pupils at schools for the blind in Burundi.

PubMed

Ruhagaze, Patrick; Njuguna, Kahaki Kimani Margaret; Kandeke, Lévi; Courtright, Paul

2013-01-01

To determine the causes of childhood blindness and severe visual impairment in pupils attending schools for the blind in Burundi in order to assist planning for services in the country. All pupils attending three schools for the blind in Burundi were examined. A modified WHO/PBL eye examination record form for children with blindness and low vision was used to record the findings. Data was analyzed for those who became blind or severely visually impaired before the age of 16 years. Overall, 117 pupils who became visually impaired before 16 years of age were examined. Of these, 109 (93.2%) were blind or severely visually impaired. The major anatomical cause of blindness or severe visual impairment was cornea pathology/phthisis (23.9%), followed by lens pathology (18.3%), uveal lesions (14.7%) and optic nerve lesions (11.9%). In the majority of pupils with blindness or severe visual impairment, the underlying etiology of visual loss was unknown (74.3%). More than half of the pupils with lens related blindness had not had surgery; among those who had surgery, outcomes were generally poor. The causes identified indicate the importance of continuing preventive public health strategies, as well as the development of specialist pediatric ophthalmic services in the management of childhood blindness in Burundi. The geographic distribution of pupils at the schools for the blind indicates a need for community-based programs to identify and refer children in need of services.

Do Multielement Visual Tracking and Visual Search Draw Continuously on the Same Visual Attention Resources?

ERIC Educational Resources Information Center

Alvarez, George A.; Horowitz, Todd S.; Arsenio, Helga C.; DiMase, Jennifer S.; Wolfe, Jeremy M.

2005-01-01

Multielement visual tracking and visual search are 2 tasks that are held to require visual-spatial attention. The authors used the attentional operating characteristic (AOC) method to determine whether both tasks draw continuously on the same attentional resource (i.e., whether the 2 tasks are mutually exclusive). The authors found that observers…

Tiger salamanders' (Ambystoma tigrinum) response learning and usage of visual cues.

PubMed

Kundey, Shannon M A; Millar, Roberto; McPherson, Justin; Gonzalez, Maya; Fitz, Aleyna; Allen, Chadbourne

2016-05-01

We explored tiger salamanders' (Ambystoma tigrinum) learning to execute a response within a maze as proximal visual cue conditions varied. In Experiment 1, salamanders learned to turn consistently in a T-maze for reinforcement before the maze was rotated. All learned the initial task and executed the trained turn during test, suggesting that they learned to demonstrate the reinforced response during training and continued to perform it during test. In a second experiment utilizing a similar procedure, two visual cues were placed consistently at the maze junction. Salamanders were reinforced for turning towards one cue. Cue placement was reversed during test. All learned the initial task, but executed the trained turn rather than turning towards the visual cue during test, evidencing response learning. In Experiment 3, we investigated whether a compound visual cue could control salamanders' behaviour when it was the only cue predictive of reinforcement in a cross-maze by varying start position and cue placement. All learned to turn in the direction indicated by the compound visual cue, indicating that visual cues can come to control their behaviour. Following training, testing revealed that salamanders attended to stimuli foreground over background features. Overall, these results suggest that salamanders learn to execute responses over learning to use visual cues but can use visual cues if required. Our success with this paradigm offers the potential in future studies to explore salamanders' cognition further, as well as to shed light on how features of the tiger salamanders' life history (e.g. hibernation and metamorphosis) impact cognition.

Alcohol and disorientation-related responses. V, The influence of alcohol on positional, rotatory, and coriolis vestibular responses over 32-hour periods.

DOT National Transportation Integrated Search

1971-10-01

There are some indications that the systems most closely associated with disorientation responses--the visual and vestibular systems--may continue to show effects of alcohol ingestion for periods in excess of 24 hours. These effects may be evident bo...

Visual recognition memory and auditory brainstem response in infant rhesus monkeys exposed perinatally to environmental tobacco smoke.

PubMed

Golub, Mari S; Slotkin, Theodore A; Tarantal, Alice F; Pinkerton, Kent E

2007-06-02

The impact of perinatal exposure to environmental tobacco smoke (ETS) on cognitive development is controversial. We exposed rhesus monkeys to ETS or filtered air (5 animals per group) beginning in utero on day 50 of pregnancy and continuing throughout postnatal testing. In infancy, we evaluated both groups for visual recognition memory and auditory function (auditory brainstem response). The ETS group showed significantly less novelty preference in the visual recognition task whereas no effects on auditory function were detected. These preliminary results support the view that perinatal ETS exposure has adverse effects on cognitive function and indicate further that rhesus monkeys may provide a valuable nonhuman primate model for investigating this link.

A Discussion of Commercially Available Intra-ocular Telescopic Implants for Patients with Age-Related Macular Degeneration.

PubMed

Dunbar, Hannah M P; Dhawahir-Scala, Felipe E

2018-06-01

Age-related macular degeneration (AMD) is the leading cause of visual impairment in the western world, causing significant reduction in quality of life. Despite treatment advances, the burden of visual impairment caused by AMD continues to rise. In addition to traditional low vision rehabilitation and support, optical and electronic aids, and strategies to enhance the use of peripheral vision, implantable telescopic devices have been indicated as a surgical means of enhancing vision. Here we examine the literature on commercially available telescopic devices discussing their design, mode of action, surgical procedure and published outcomes on visual acuity, quality of life, surgical complication rates and cost effectiveness data where available.Funding Article processing charges were funded by VisionCare Inc.

Detecting delay in visual feedback of an action as a monitor of self recognition.

PubMed

Hoover, Adria E N; Harris, Laurence R

2012-10-01

How do we distinguish "self" from "other"? The correlation between willing an action and seeing it occur is an important cue. We exploited the fact that this correlation needs to occur within a restricted temporal window in order to obtain a quantitative assessment of when a body part is identified as "self". We measured the threshold and sensitivity (d') for detecting a delay between movements of the finger (of both the dominant and non-dominant hands) and visual feedback as seen from four visual perspectives (the natural view, and mirror-reversed and/or inverted views). Each trial consisted of one presentation with minimum delay and another with a delay of between 33 and 150 ms. Participants indicated which presentation contained the delayed view. We varied the amount of efference copy available for this task by comparing performances for discrete movements and continuous movements. Discrete movements are associated with a stronger efference copy. Sensitivity to detect asynchrony between visual and proprioceptive information was significantly higher when movements were viewed from a "plausible" self perspective compared with when the view was reversed or inverted. Further, we found differences in performance between dominant and non-dominant hand finger movements across the continuous and single movements. Performance varied with the viewpoint from which the visual feedback was presented and on the efferent component such that optimal performance was obtained when the presentation was in the normal natural orientation and clear efferent information was available. Variations in sensitivity to visual/non-visual temporal incongruence with the viewpoint in which a movement is seen may help determine the arrangement of the underlying visual representation of the body.

Pseudohaptic interaction with knot diagrams

NASA Astrophysics Data System (ADS)

Weng, Jianguang; Zhang, Hui

2012-07-01

To make progress in understanding knot theory, we need to interact with the projected representations of mathematical knots, which are continuous in three dimensions (3-D) but significantly interrupted in the projective images. One way to achieve such a goal is to design an interactive system that allows us to sketch two-dimensional (2-D) knot diagrams by taking advantage of a collision-sensing controller and explore their underlying smooth structures through a continuous motion. Recent advances of interaction techniques have been made that allow progress in this direction. Pseudohaptics that simulate haptic effects using pure visual feedback can be used to develop such an interactive system. We outline one such pseudohaptic knot diagram interface. Our interface derives from the familiar pencil-and-paper process of drawing 2-D knot diagrams and provides haptic-like sensations to facilitate the creation and exploration of knot diagrams. A centerpiece of the interaction model simulates a physically reactive mouse cursor, which is exploited to resolve the apparent conflict between the continuous structure of the actual smooth knot and the visual discontinuities in the knot diagram representation. Another value in exploiting pseudohaptics is that an acceleration (or deceleration) of the mouse cursor (or surface locator) can be used to indicate the slope of the curve (or surface) of which the projective image is being explored. By exploiting these additional visual cues, we proceed to a full-featured extension to a pseudohaptic four-dimensional (4-D) visualization system that simulates the continuous navigation on 4-D objects and allows us to sense the bumps and holes in the fourth dimension. Preliminary tests of the software show that main features of the interface overcome some expected perceptual limitations in our interaction with 2-D knot diagrams of 3-D knots and 3-D projective images of 4-D mathematical objects.

Visual Method for Detecting Contaminant on Dried Nutmeg Using Fluorescence Imaging

NASA Astrophysics Data System (ADS)

Dahlan, S. A.; Ahmad, U.; Subrata, I. D. M.

2018-05-01

Traditional practice of nutmeg sun-drying causes some fungi such as Aspergillus flavus to grow. One of the secondary metabolites of A. flavus named aflatoxin (AFs) is known to be carcinogenic, so the dried nutmeg kernel must be aflatoxin-free in the trading. Aflatoxin detection requires time and costly, make it difficult to conduct at the farmers level. This study aims to develop a simple and low-cost method to detect aflatoxin at the farmer level. Fresh nutmeg seeds were dried in two ways; sundried everyday (continuous), and sundried every two days (intermittent), both for around 18 days. The dried nutmeg seeds are then stored in a rice sack under normal conditions until the fungi grow, then they were opened and the images of kernels were captured using a CCD camera, with normal light and UV light sources. Visual observation on images captured in normal light source was able to detect the presence of fungi on dried kernels, by 28.0% for continuous and 26.2% for intermittent sun-drying. Visual observation on images captured in UV light source was able to detect the presence of aflatoxin on dried kernels, indicated by blue luminance on kernel, by 10.4% and 13.4% for continuous and intermittent sun-drying.

The VIS-AD data model: Integrating metadata and polymorphic display with a scientific programming language

NASA Technical Reports Server (NTRS)

Hibbard, William L.; Dyer, Charles R.; Paul, Brian E.

1994-01-01

The VIS-AD data model integrates metadata about the precision of values, including missing data indicators and the way that arrays sample continuous functions, with the data objects of a scientific programming language. The data objects of this data model form a lattice, ordered by the precision with which they approximate mathematical objects. We define a similar lattice of displays and study visualization processes as functions from data lattices to display lattices. Such functions can be applied to visualize data objects of all data types and are thus polymorphic.

Manipulation of the extrastriate frontal loop can resolve visual disability in blindsight patients.

PubMed

Badgaiyan, Rajendra D

2012-12-01

Patients with blindsight are not consciously aware of visual stimuli in the affected field of vision but retain nonconscious perception. This disability can be resolved if nonconsciously perceived information can be brought to their conscious awareness. It can be accomplished by manipulating neural network of visual awareness. To understand this network, we studied the pattern of cortical activity elicited during processing of visual stimuli with or without conscious awareness. The analysis indicated that a re-entrant signaling loop between the area V3A (located in the extrastriate cortex) and the frontal cortex is critical for processing conscious awareness. The loop is activated by visual signals relayed in the primary visual cortex, which is damaged in blindsight patients. Because of the damage, V3A-frontal loop is not activated and the signals are not processed for conscious awareness. These patients however continue to receive visual signals through the lateral geniculate nucleus. Since these signals do not activate the V3A-frontal loop, the stimuli are not consciously perceived. If visual input from the lateral geniculate nucleus is appropriately manipulated and made to activate the V3A-frontal loop, blindsight patients can regain conscious vision. Published by Elsevier Ltd.

Combined visual illusion effects on the perceived index of difficulty and movement outcomes in discrete and continuous fitts' tapping.

PubMed

Alphonsa, Sushma; Dai, Boyi; Benham-Deal, Tami; Zhu, Qin

2016-01-01

The speed-accuracy trade-off is a fundamental movement problem that has been extensively investigated. It has been established that the speed at which one can move to tap targets depends on how large the targets are and how far they are apart. These spatial properties of the targets can be quantified by the index of difficulty (ID). Two visual illusions are known to affect the perception of target size and movement amplitude: the Ebbinghaus illusion and Muller-Lyer illusion. We created visual images that combined these two visual illusions to manipulate the perceived ID, and then examined people's visual perception of the targets in illusory context as well as their performance in tapping those targets in both discrete and continuous manners. The findings revealed that the combined visual illusions affected the perceived ID similarly in both discrete and continuous judgment conditions. However, the movement outcomes were affected by the combined visual illusions according to the tapping mode. In discrete tapping, the combined visual illusions affected both movement accuracy and movement amplitude such that the effective ID resembled the perceived ID. In continuous tapping, none of the movement outcomes were affected by the combined visual illusions. Participants tapped the targets with higher speed and accuracy in all visual conditions. Based on these findings, we concluded that distinct visual-motor control mechanisms were responsible for execution of discrete and continuous Fitts' tapping. Although discrete tapping relies on allocentric information (object-centered) to plan for action, continuous tapping relies on egocentric information (self-centered) to control for action. The planning-control model for rapid aiming movements is supported.

Sport stacking in auditory and visual attention of grade 3 learners.

PubMed

Mortimer, J; Krysztofiak, J; Custard, S; McKune, A J

2011-08-01

The effect of sport stacking on auditory and visual attention in 32 Grade 3 children was examined using a randomised, cross-over design. Children were randomly assigned to a sport stacking (n=16) or arts/crafts group (n=16) with these activities performed over 3 wk. (12 30-min. sessions, 4 per week). This was followed by a 3-wk. wash-out period after which there was a cross-over and the 3-wk. intervention repeated, with the sports stacking group performing arts/crafts and the arts/crafts group performing sports stacking. Performance on the Integrated Visual and Auditory Continuous Performance Test, a measure of auditory and visual attention, was assessed before and after each of the 3-wk. interventions for each group. Comparisons indicated that sport stacking resulted in significant improvement in high demand function and fine motor regulation, while it caused a significant reduction in low demand function. Auditory and visual attention adaptations to sport stacking may be specific to the high demand nature of the task.

Developmental Changes in the Processing of Hierarchical Shapes Continue into Adolescence.

ERIC Educational Resources Information Center

Mondloch, Catherine J.; Geldart, Sybil; Maurer, Daphne; de Schonen, Scania

2003-01-01

Three experiments obtained same-different judgments from children and adults to trace normal development of local and global processing of hierarchical visual forms. Findings indicated that reaction time was faster on global trials than local trials; bias was stronger in children and diminished to adult levels between ages 10 and 14. Reaction time…

SU-E-J-72: Design and Study of In-House Web-Camera Based Automatic Continuous Patient Movement Monitoring and Controlling Device for EXRT.

PubMed

Senthil Kumar, S; Suresh Babu, S S; Anand, P; Dheva Shantha Kumari, G

2012-06-01

The purpose of our study was to fabricate in-house web-camera based automatic continuous patient movement monitoring device and control the movement of the patients during EXRT. Web-camera based patient movement monitoring device consists of a computer, digital web-camera, mounting system, breaker circuit, speaker, and visual indicator. The computer is used to control and analyze the patient movement using indigenously developed software. The speaker and the visual indicator are placed in the console room to indicate the positional displacement of the patient. Studies were conducted on phantom and 150 patients with different types of cancers. Our preliminary clinical results indicate that our device is highly reliable and can accurately report smaller movements of the patients in all directions. The results demonstrated that the device was able to detect patient's movements with the sensitivity of about 1 mm. When a patient moves, the receiver activates the circuit; an audible warning sound will be produced in the console. Through real-time measurements, an audible alarm can alert the radiation technologist to stop the treatment if the user defined positional threshold is violated. Simultaneously, the electrical circuit to the teletherapy machine will be activated and radiation will be halted. Patient's movement during the course for radiotherapy was studied. The beam is halted automatically when the threshold level of the system is exceeded. By using the threshold provided in the system, it is possible to monitor the patient continuously with certain fixed limits. An additional benefit is that it has reduced the tension and stress of a treatment team associated with treating patients who are not immobilized. It also enables the technologists to do their work more efficiently, because they don't have to continuously monitor patients with as much scrutiny as was required. © 2012 American Association of Physicists in Medicine.

Oculomotor guidance and capture by irrelevant faces.

PubMed

Devue, Christel; Belopolsky, Artem V; Theeuwes, Jan

2012-01-01

Even though it is generally agreed that face stimuli constitute a special class of stimuli, which are treated preferentially by our visual system, it remains unclear whether faces can capture attention in a stimulus-driven manner. Moreover, there is a long-standing debate regarding the mechanism underlying the preferential bias of selecting faces. Some claim that faces constitute a set of special low-level features to which our visual system is tuned; others claim that the visual system is capable of extracting the meaning of faces very rapidly, driving attentional selection. Those debates continue because many studies contain methodological peculiarities and manipulations that prevent a definitive conclusion. Here, we present a new visual search task in which observers had to make a saccade to a uniquely colored circle while completely irrelevant objects were also present in the visual field. The results indicate that faces capture and guide the eyes more than other animated objects and that our visual system is not only tuned to the low-level features that make up a face but also to its meaning.

Feature bindings endure without attention: evidence from an explicit recall task.

PubMed

Gajewski, Daniel A; Brockmole, James R

2006-08-01

Are integrated objects the unit of capacity of visual working memory, or is continued attention needed to maintain bindings between independently stored features? In a delayed recall task, participants reported the color and shape of a probed item from a memory array. During the delay, attention was manipulated with an exogenous cue. Recall was elevated at validly cued positions, indicating that the cue affected item memory. On invalid trials, participants most frequently recalled either both features (perfect object memory) or neither of the two features (no object memory); the frequency with which only one feature was recalled was significantly lower than predicted by feature independence as determined in a single-feature recall task. These data do not support the view that features are remembered independently when attention is withdrawn. Instead, integrated objects are stored in visual working memory without need for continued attention.

Effects of body lean and visual information on the equilibrium maintenance during stance.

PubMed

Duarte, Marcos; Zatsiorsky, Vladimir M

2002-09-01

Maintenance of equilibrium was tested in conditions when humans assume different leaning postures during upright standing. Subjects ( n=11) stood in 13 different body postures specified by visual center of pressure (COP) targets within their base of support (BOS). Different types of visual information were tested: continuous presentation of visual target, no vision after target presentation, and with simultaneous visual feedback of the COP. The following variables were used to describe the equilibrium maintenance: the mean of the COP position, the area of the ellipse covering the COP sway, and the resultant median frequency of the power spectral density of the COP displacement. The variability of the COP displacement, quantified by the COP area variable, increased when subjects occupied leaning postures, irrespective of the kind of visual information provided. This variability also increased when vision was removed in relation to when vision was present. Without vision, drifts in the COP data were observed which were larger for COP targets farther away from the neutral position. When COP feedback was given in addition to the visual target, the postural control system did not control stance better than in the condition with only visual information. These results indicate that the visual information is used by the postural control system at both short and long time scales.

Horizontal visual search in a large field by patients with unilateral spatial neglect.

PubMed

Nakatani, Ken; Notoya, Masako; Sunahara, Nobuyuki; Takahashi, Shusuke; Inoue, Katsumi

2013-06-01

In this study, we investigated the horizontal visual search ability and pattern of horizontal visual search in a large space performed by patients with unilateral spatial neglect (USN). Subjects included nine patients with right hemisphere damage caused by cerebrovascular disease showing left USN, nine patients with right hemisphere damage but no USN, and six healthy individuals with no history of brain damage who were age-matched to the groups with brain right hemisphere damage. The number of visual search tasks accomplished was recorded in the first experiment. Neck rotation angle was continuously measured during the task and quantitative data of the measurements were collected. There was a strong correlation between the number of visual search tasks accomplished and the total Behavioral Inattention Test Conventional Subtest (BITC) score in subjects with right hemisphere damage. In both USN and control groups, the head position during the visual search task showed a balanced bell-shaped distribution from the central point on the field to the left and right sides. Our results indicate that compensatory strategies, including cervical rotation, may improve visual search capability and achieve balance on the neglected side. Copyright © 2012 Elsevier Ltd. All rights reserved.

Noninvasive diagnosis of right-sided extracardiac conduit obstruction by combined magnetic resonance imaging and continuous-wave Doppler echocardiography.

PubMed

Canter, C E; Gutierrez, F R; Molina, P; Hartmann, A F; Spray, T L

1991-04-01

Right-sided extracardiac conduits are frequently complicated by obstruction over time. We compared the utility of two-dimensional and Doppler echocardiography and magnetic resonance imaging in the diagnosis of postoperative right-sided obstruction with cardiac catheterization and angiography in 10 patients with xenograft or homograft conduits. Correlation (r = 0.95) between continuous-wave Doppler estimates and catheter pullback pressure gradients across the conduits was excellent. Echocardiography could only visualize five of 10 conduits in their entirety. Magnetic resonance imaging visualized all conduits and showed statistically significant (kappa = 0.58) agreement with angiography in the localization and estimation of severity of a variety of right-sided obstructions in these patients. However, flow voids created by the metallic ring around xenograft valves led to a false negative diagnosis of valvular stenosis in four patients when magnetic resonance imaging was used alone. Doppler studies correctly indicated obstruction in these patients. The combination of magnetic resonance imaging studies and continuous-wave Doppler echocardiography can be useful to noninvasively evaluate right-sided obstruction in postoperative patients with right-sided extracardiac conduits.

Comparison of Amplitude-Integrated EEG and Conventional EEG in a Cohort of Premature Infants.

PubMed

Meledin, Irina; Abu Tailakh, Muhammad; Gilat, Shlomo; Yogev, Hagai; Golan, Agneta; Novack, Victor; Shany, Eilon

2017-03-01

To compare amplitude-integrated EEG (aEEG) and conventional EEG (EEG) activity in premature neonates. Biweekly aEEG and EEG were simultaneously recorded in a cohort of infants born less than 34 weeks gestation. aEEG recordings were visually assessed for lower and upper border amplitude and bandwidth. EEG recordings were compressed for visual evaluation of continuity and assessed using a signal processing software for interburst intervals (IBI) and frequencies' amplitude. Ten-minute segments of aEEG and EEG indices were compared using regression analysis. A total of 189 recordings from 67 infants were made, from which 1697 aEEG/EEG pairs of 10-minute segments were assessed. Good concordance was found for visual assessment of continuity between the 2 methods. EEG IBI, alpha and theta frequencies' amplitudes were negatively correlated to the aEEG lower border while conceptional age (CA) was positively correlated to aEEG lower border ( P < .001). IBI and all frequencies' amplitude were positively correlated to the upper aEEG border ( P ≤ .001). CA was negatively correlated to aEEG span while IBI, alpha, beta, and theta frequencies' amplitude were positively correlated to the aEEG span. Important information is retained and integrated in the transformation of premature neonatal EEG to aEEG. aEEG recordings in high-risk premature neonates reflect reliably EEG background information related to continuity and amplitude.

Complex regional pain syndrome (CRPS) or continuous unilateral distal experimental pain stimulation in healthy subjects does not bias visual attention towards one hemifield.

PubMed

Filippopulos, Filipp M; Grafenstein, Jessica; Straube, Andreas; Eggert, Thomas

2015-11-01

In natural life pain automatically draws attention towards the painful body part suggesting that it interacts with different attentional mechanisms such as visual attention. Complex regional pain syndrome (CRPS) patients who typically report on chronic distally located pain of one extremity may suffer from so-called neglect-like symptoms, which have also been linked to attentional mechanisms. The purpose of the study was to further evaluate how continuous pain conditions influence visual attention. Saccade latencies were recorded in two experiments using a common visual attention paradigm whereby orientating saccades to cued or uncued lateral visual targets had to be performed. In the first experiment saccade latencies of healthy subjects were measured under two conditions: one in which continuous experimental pain stimulation was applied to the index finger to imitate a continuous pain situation, and one without pain stimulation. In the second experiment saccade latencies of patients suffering from CRPS were compared to controls. The results showed that neither the continuous experimental pain stimulation during the experiment nor the chronic pain in CRPS led to an unilateral increase of saccade latencies or to a unilateral increase of the cue effect on latency. The results show that unilateral, continuously applied pain stimuli or chronic pain have no or only very limited influence on visual attention. Differently from patients with visual neglect, patients with CRPS did not show strong side asymmetries of saccade latencies or of cue effects on saccade latencies. Thus, neglect-like clinical symptoms of CRPS patients do not involve the allocation of visual attention.

Figure-ground organization and the emergence of proto-objects in the visual cortex.

PubMed

von der Heydt, Rüdiger

2015-01-01

A long history of studies of perception has shown that the visual system organizes the incoming information early on, interpreting the 2D image in terms of a 3D world and producing a structure that provides perceptual continuity and enables object-based attention. Recordings from monkey visual cortex show that many neurons, especially in area V2, are selective for border ownership. These neurons are edge selective and have ordinary classical receptive fields (CRF), but in addition their responses are modulated (enhanced or suppressed) depending on the location of a 'figure' relative to the edge in their receptive field. Each neuron has a fixed preference for location on one side or the other. This selectivity is derived from the image context far beyond the CRF. This paper reviews evidence indicating that border ownership selectivity reflects the formation of early object representations ('proto-objects'). The evidence includes experiments showing (1) reversal of border ownership signals with change of perceived object structure, (2) border ownership specific enhancement of responses in object-based selective attention, (3) persistence of border ownership signals in accordance with continuity of object perception, and (4) remapping of border ownership signals across saccades and object movements. Findings 1 and 2 can be explained by hypothetical grouping circuits that sum contour feature signals in search of objectness, and, via recurrent projections, enhance the corresponding low-level feature signals. Findings 3 and 4 might be explained by assuming that the activity of grouping circuits persists and can be remapped. Grouping, persistence, and remapping are fundamental operations of vision. Finding these operations manifest in low-level visual areas challenges traditional views of visual processing. New computational models need to be developed for a comprehensive understanding of the function of the visual cortex.

Figure–ground organization and the emergence of proto-objects in the visual cortex

PubMed Central

von der Heydt, Rüdiger

2015-01-01

A long history of studies of perception has shown that the visual system organizes the incoming information early on, interpreting the 2D image in terms of a 3D world and producing a structure that provides perceptual continuity and enables object-based attention. Recordings from monkey visual cortex show that many neurons, especially in area V2, are selective for border ownership. These neurons are edge selective and have ordinary classical receptive fields (CRF), but in addition their responses are modulated (enhanced or suppressed) depending on the location of a ‘figure’ relative to the edge in their receptive field. Each neuron has a fixed preference for location on one side or the other. This selectivity is derived from the image context far beyond the CRF. This paper reviews evidence indicating that border ownership selectivity reflects the formation of early object representations (‘proto-objects’). The evidence includes experiments showing (1) reversal of border ownership signals with change of perceived object structure, (2) border ownership specific enhancement of responses in object-based selective attention, (3) persistence of border ownership signals in accordance with continuity of object perception, and (4) remapping of border ownership signals across saccades and object movements. Findings 1 and 2 can be explained by hypothetical grouping circuits that sum contour feature signals in search of objectness, and, via recurrent projections, enhance the corresponding low-level feature signals. Findings 3 and 4 might be explained by assuming that the activity of grouping circuits persists and can be remapped. Grouping, persistence, and remapping are fundamental operations of vision. Finding these operations manifest in low-level visual areas challenges traditional views of visual processing. New computational models need to be developed for a comprehensive understanding of the function of the visual cortex. PMID:26579062

Algebraic Reasoning in Solving Mathematical Problem Based on Learning Style

NASA Astrophysics Data System (ADS)

Indraswari, N. F.; Budayasa, I. K.; Ekawati, R.

2018-01-01

This study aimed to describe algebraic reasoning of secondary school’s pupils with different learning styles in solving mathematical problem. This study begins by giving the questionnaire to find out the learning styles and followed by mathematical ability test to get three subjects of 8th-grade whereas the learning styles of each pupil is visual, auditory, kinesthetic and had similar mathematical abilities. Then it continued with given algebraic problems and interviews. The data is validated using triangulation of time. The result showed that in the pattern of seeking indicator, subjects identified the things that were known and asked based on them observations. The visual and kinesthetic learners represented the known information in a chart, whereas the auditory learner in a table. In addition, they found the elements which makes the pattern and made a relationship between two quantities. In the pattern recognition indicator, they created conjectures on the relationship between two quantities and proved it. In the generalization indicator, they were determining the general rule of pattern found on each element of pattern using algebraic symbols and created a mathematical model. Visual and kinesthetic learners determined the general rule of equations which was used to solve problems using algebraic symbols, but auditory learner in a sentence.

Glyph-based generic network visualization

NASA Astrophysics Data System (ADS)

Erbacher, Robert F.

2002-03-01

Network managers and system administrators have an enormous task set before them in this day of growing network usage. This is particularly true of e-commerce companies and others dependent on a computer network for their livelihood. Network managers and system administrators must monitor activity for intrusions and misuse while at the same time monitoring performance of the network. In this paper, we describe our visualization techniques for assisting in the monitoring of networks for both of these tasks. The goal of these visualization techniques is to integrate the visual representation of both network performance/usage as well as data relevant to intrusion detection. The main difficulties arise from the difference in the intrinsic data and layout needs of each of these tasks. Glyph based techniques are additionally used to indicate the representative values of the necessary data parameters over time. Additionally, our techniques are geared towards providing an environment that can be used continuously for constant real-time monitoring of the network environment.

Development of closed-loop neural interface technology in a rat model: combining motor cortex operant conditioning with visual cortex microstimulation.

PubMed

Marzullo, Timothy Charles; Lehmkuhle, Mark J; Gage, Gregory J; Kipke, Daryl R

2010-04-01

Closed-loop neural interface technology that combines neural ensemble decoding with simultaneous electrical microstimulation feedback is hypothesized to improve deep brain stimulation techniques, neuromotor prosthetic applications, and epilepsy treatment. Here we describe our iterative results in a rat model of a sensory and motor neurophysiological feedback control system. Three rats were chronically implanted with microelectrode arrays in both the motor and visual cortices. The rats were subsequently trained over a period of weeks to modulate their motor cortex ensemble unit activity upon delivery of intra-cortical microstimulation (ICMS) of the visual cortex in order to receive a food reward. Rats were given continuous feedback via visual cortex ICMS during the response periods that was representative of the motor cortex ensemble dynamics. Analysis revealed that the feedback provided the animals with indicators of the behavioral trials. At the hardware level, this preparation provides a tractable test model for improving the technology of closed-loop neural devices.

A pseudo-haptic knot diagram interface

NASA Astrophysics Data System (ADS)

Zhang, Hui; Weng, Jianguang; Hanson, Andrew J.

2011-01-01

To make progress in understanding knot theory, we will need to interact with the projected representations of mathematical knots which are of course continuous in 3D but significantly interrupted in the projective images. One way to achieve such a goal would be to design an interactive system that allows us to sketch 2D knot diagrams by taking advantage of a collision-sensing controller and explore their underlying smooth structures through a continuous motion. Recent advances of interaction techniques have been made that allow progress to be made in this direction. Pseudo-haptics that simulates haptic effects using pure visual feedback can be used to develop such an interactive system. This paper outlines one such pseudo-haptic knot diagram interface. Our interface derives from the familiar pencil-and-paper process of drawing 2D knot diagrams and provides haptic-like sensations to facilitate the creation and exploration of knot diagrams. A centerpiece of the interaction model simulates a "physically" reactive mouse cursor, which is exploited to resolve the apparent conflict between the continuous structure of the actual smooth knot and the visual discontinuities in the knot diagram representation. Another value in exploiting pseudo-haptics is that an acceleration (or deceleration) of the mouse cursor (or surface locator) can be used to indicate the slope of the curve (or surface) of whom the projective image is being explored. By exploiting these additional visual cues, we proceed to a full-featured extension to a pseudo-haptic 4D visualization system that simulates the continuous navigation on 4D objects and allows us to sense the bumps and holes in the fourth dimension. Preliminary tests of the software show that main features of the interface overcome some expected perceptual limitations in our interaction with 2D knot diagrams of 3D knots and 3D projective images of 4D mathematical objects.

Rapid Extraction of Lexical Tone Phonology in Chinese Characters: A Visual Mismatch Negativity Study

PubMed Central

Wang, Xiao-Dong; Liu, A-Ping; Wu, Yin-Yuan; Wang, Peng

2013-01-01

Background In alphabetic languages, emerging evidence from behavioral and neuroimaging studies shows the rapid and automatic activation of phonological information in visual word recognition. In the mapping from orthography to phonology, unlike most alphabetic languages in which there is a natural correspondence between the visual and phonological forms, in logographic Chinese, the mapping between visual and phonological forms is rather arbitrary and depends on learning and experience. The issue of whether the phonological information is rapidly and automatically extracted in Chinese characters by the brain has not yet been thoroughly addressed. Methodology/Principal Findings We continuously presented Chinese characters differing in orthography and meaning to adult native Mandarin Chinese speakers to construct a constant varying visual stream. In the stream, most stimuli were homophones of Chinese characters: The phonological features embedded in these visual characters were the same, including consonants, vowels and the lexical tone. Occasionally, the rule of phonology was randomly violated by characters whose phonological features differed in the lexical tone. Conclusions/Significance We showed that the violation of the lexical tone phonology evoked an early, robust visual response, as revealed by whole-head electrical recordings of the visual mismatch negativity (vMMN), indicating the rapid extraction of phonological information embedded in Chinese characters. Source analysis revealed that the vMMN was involved in neural activations of the visual cortex, suggesting that the visual sensory memory is sensitive to phonological information embedded in visual words at an early processing stage. PMID:23437235

Visualization of 3D elbow kinematics using reconstructed bony surfaces

NASA Astrophysics Data System (ADS)

Lalone, Emily A.; McDonald, Colin P.; Ferreira, Louis M.; Peters, Terry M.; King, Graham J. W.; Johnson, James A.

2010-02-01

An approach for direct visualization of continuous three-dimensional elbow kinematics using reconstructed surfaces has been developed. Simulation of valgus motion was achieved in five cadaveric specimens using an upper arm simulator. Direct visualization of the motion of the ulna and humerus at the ulnohumeral joint was obtained using a contact based registration technique. Employing fiducial markers, the rendered humerus and ulna were positioned according to the simulated motion. The specific aim of this study was to investigate the effect of radial head arthroplasty on restoring elbow joint stability after radial head excision. The position of the ulna and humerus was visualized for the intact elbow and following radial head excision and replacement. Visualization of the registered humerus/ulna indicated an increase in valgus angulation of the ulna with respect to the humerus after radial head excision. This increase in valgus angulation was restored to that of an elbow with a native radial head following radial head arthroplasty. These findings were consistent with previous studies investigating elbow joint stability following radial head excision and arthroplasty. The current technique was able to visualize a change in ulnar position in a single DoF. Using this approach, the coupled motion of ulna undergoing motion in all 6 degrees-of-freedom can also be visualized.

Discrete Events as Units of Perceived Time

ERIC Educational Resources Information Center

Liverence, Brandon M.; Scholl, Brian J.

2012-01-01

In visual images, we perceive both space (as a continuous visual medium) and objects (that inhabit space). Similarly, in dynamic visual experience, we perceive both continuous time and discrete events. What is the relationship between these units of experience? The most intuitive answer may be similar to the spatial case: time is perceived as an…

Visual Acuity Improvement in Continuous vs Divided Occlusion in Anisometropic Amblyopia

PubMed Central

Irfani, Irawati; Feriyanto, Feri; Oktarima, Primawita; Kartasasmita, Arief

2018-01-01

Purpose: To compare visual acuity improvement between continuous and split part-time occlusion for the treatment of moderate and severe anisometropic amblyopia. Methods: Randomised clinical trials in 6 – 13 y.o children with moderate and severe anisometropic amblyopia. Each patient was consecutively selected with continuous or split part-time occlusion. Best corrected visual acuity’s improvement was followed up to six weeks and statistical data were analyzed using chi square and unpaired t-test. Results: Best corrected visual acuity’s improvement was comparable between continuous and split part-time occlusion (0.20±0.27 vs 0.21±0.25; p = 0.79). Conclusion: Split part-time occlusion may be considered as an alternative treatment for moderate and severe anisometropic amblyopia treatment. PMID:29515681

An invisible touch: Body-related multisensory conflicts modulate visual consciousness.

PubMed

Salomon, Roy; Galli, Giulia; Łukowska, Marta; Faivre, Nathan; Ruiz, Javier Bello; Blanke, Olaf

2016-07-29

The majority of scientific studies on consciousness have focused on vision, exploring the cognitive and neural mechanisms of conscious access to visual stimuli. In parallel, studies on bodily consciousness have revealed that bodily (i.e. tactile, proprioceptive, visceral, vestibular) signals are the basis for the sense of self. However, the role of bodily signals in the formation of visual consciousness is not well understood. Here we investigated how body-related visuo-tactile stimulation modulates conscious access to visual stimuli. We used a robotic platform to apply controlled tactile stimulation to the participants' back while they viewed a dot moving either in synchrony or asynchrony with the touch on their back. Critically, the dot was rendered invisible through continuous flash suppression. Manipulating the visual context by presenting the dot moving on either a body form, or a non-bodily object we show that: (i) conflict induced by synchronous visuo-tactile stimulation in a body context is associated with a delayed conscious access compared to asynchronous visuo-tactile stimulation, (ii) this effect occurs only in the context of a visual body form, and (iii) is not due to detection or response biases. The results indicate that body-related visuo-tactile conflicts impact visual consciousness by facilitating access of non-conflicting visual information to awareness, and that these are sensitive to the visual context in which they are presented, highlighting the interplay between bodily signals and visual experience. Copyright © 2015 Elsevier Ltd. All rights reserved.

On the Treatment of Field Quantities and Elemental Continuity in FEM Solutions.

PubMed

Jallepalli, Ashok; Docampo-Sanchez, Julia; Ryan, Jennifer K; Haimes, Robert; Kirby, Robert M

2018-01-01

As the finite element method (FEM) and the finite volume method (FVM), both traditional and high-order variants, continue their proliferation into various applied engineering disciplines, it is important that the visualization techniques and corresponding data analysis tools that act on the results produced by these methods faithfully represent the underlying data. To state this in another way: the interpretation of data generated by simulation needs to be consistent with the numerical schemes that underpin the specific solver technology. As the verifiable visualization literature has demonstrated: visual artifacts produced by the introduction of either explicit or implicit data transformations, such as data resampling, can sometimes distort or even obfuscate key scientific features in the data. In this paper, we focus on the handling of elemental continuity, which is often only continuous or piecewise discontinuous, when visualizing primary or derived fields from FEM or FVM simulations. We demonstrate that traditional data handling and visualization of these fields introduce visual errors. In addition, we show how the use of the recently proposed line-SIAC filter provides a way of handling elemental continuity issues in an accuracy-conserving manner with the added benefit of casting the data in a smooth context even if the representation is element discontinuous.

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

PubMed Central

Tanahashi, Shigehito; Ashihara, Kaoru; Ujike, Hiroyasu

2015-01-01

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

The riddle of style changes in the visual arts after interference with the right brain.

PubMed

Blanke, Olaf; Pasqualini, Isabella

2011-01-01

We here analyze the paintings and films of several visual artists, who suffered from a well-defined neuropsychological deficit, visuo-spatial hemineglect, following vascular stroke to the right brain. In our analysis we focus in particular on the oeuvre of Lovis Corinth and Luchino Visconti as both major artists continued to be highly productive over many years after their right brain damage. We analyzed their post-stroke paintings and films, indicate several aspects that differ from their pre-stroke work (omissions, use of color, perseveration, deformation), and propose-although both artists come from different times, countries, genres, and styles-that their post-stroke oeuvre reveals important similarities in style. We argue that these changes may be associated with visuo-spatial hemineglect and the right brain. We discuss future avenues of how the neuropsychological investigation of visual artists with and without neglect may allow us to investigate the relationship between brain and art.

A method for real-time visual stimulus selection in the study of cortical object perception.

PubMed

Leeds, Daniel D; Tarr, Michael J

2016-06-01

The properties utilized by visual object perception in the mid- and high-level ventral visual pathway are poorly understood. To better establish and explore possible models of these properties, we adopt a data-driven approach in which we repeatedly interrogate neural units using functional Magnetic Resonance Imaging (fMRI) to establish each unit's image selectivity. This approach to imaging necessitates a search through a broad space of stimulus properties using a limited number of samples. To more quickly identify the complex visual features underlying human cortical object perception, we implemented a new functional magnetic resonance imaging protocol in which visual stimuli are selected in real-time based on BOLD responses to recently shown images. Two variations of this protocol were developed, one relying on natural object stimuli and a second based on synthetic object stimuli, both embedded in feature spaces based on the complex visual properties of the objects. During fMRI scanning, we continuously controlled stimulus selection in the context of a real-time search through these image spaces in order to maximize neural responses across pre-determined 1cm(3) rain regions. Elsewhere we have reported the patterns of cortical selectivity revealed by this approach (Leeds et al., 2014). In contrast, here our objective is to present more detailed methods and explore the technical and biological factors influencing the behavior of our real-time stimulus search. We observe that: 1) Searches converged more reliably when exploring a more precisely parameterized space of synthetic objects; 2) real-time estimation of cortical responses to stimuli is reasonably consistent; 3) search behavior was acceptably robust to delays in stimulus displays and subject motion effects. Overall, our results indicate that real-time fMRI methods may provide a valuable platform for continuing study of localized neural selectivity, both for visual object representation and beyond. Copyright © 2016 Elsevier Inc. All rights reserved.

A method for real-time visual stimulus selection in the study of cortical object perception

PubMed Central

Leeds, Daniel D.; Tarr, Michael J.

2016-01-01

The properties utilized by visual object perception in the mid- and high-level ventral visual pathway are poorly understood. To better establish and explore possible models of these properties, we adopt a data-driven approach in which we repeatedly interrogate neural units using functional Magnetic Resonance Imaging (fMRI) to establish each unit’s image selectivity. This approach to imaging necessitates a search through a broad space of stimulus properties using a limited number of samples. To more quickly identify the complex visual features underlying human cortical object perception, we implemented a new functional magnetic resonance imaging protocol in which visual stimuli are selected in real-time based on BOLD responses to recently shown images. Two variations of this protocol were developed, one relying on natural object stimuli and a second based on synthetic object stimuli, both embedded in feature spaces based on the complex visual properties of the objects. During fMRI scanning, we continuously controlled stimulus selection in the context of a real-time search through these image spaces in order to maximize neural responses across predetermined 1 cm3 brain regions. Elsewhere we have reported the patterns of cortical selectivity revealed by this approach (Leeds 2014). In contrast, here our objective is to present more detailed methods and explore the technical and biological factors influencing the behavior of our real-time stimulus search. We observe that: 1) Searches converged more reliably when exploring a more precisely parameterized space of synthetic objects; 2) Real-time estimation of cortical responses to stimuli are reasonably consistent; 3) Search behavior was acceptably robust to delays in stimulus displays and subject motion effects. Overall, our results indicate that real-time fMRI methods may provide a valuable platform for continuing study of localized neural selectivity, both for visual object representation and beyond. PMID:26973168

Large Terrain Continuous Level of Detail 3D Visualization Tool

NASA Technical Reports Server (NTRS)

Myint, Steven; Jain, Abhinandan

2012-01-01

This software solved the problem of displaying terrains that are usually too large to be displayed on standard workstations in real time. The software can visualize terrain data sets composed of billions of vertices, and can display these data sets at greater than 30 frames per second. The Large Terrain Continuous Level of Detail 3D Visualization Tool allows large terrains, which can be composed of billions of vertices, to be visualized in real time. It utilizes a continuous level of detail technique called clipmapping to support this. It offloads much of the work involved in breaking up the terrain into levels of details onto the GPU (graphics processing unit) for faster processing.

Bimanual Coordination Learning with Different Augmented Feedback Modalities and Information Types

PubMed Central

Chiou, Shiau-Chuen; Chang, Erik Chihhung

2016-01-01

Previous studies have shown that bimanual coordination learning is more resistant to the removal of augmented feedback when acquired with auditory than with visual channel. However, it is unclear whether this differential “guidance effect” between feedback modalities is due to enhanced sensorimotor integration via the non-dominant auditory channel or strengthened linkage to kinesthetic information under rhythmic input. The current study aimed to examine how modalities (visual vs. auditory) and information types (continuous visuospatial vs. discrete rhythmic) of concurrent augmented feedback influence bimanual coordination learning. Participants either learned a 90°-out-of-phase pattern for three consecutive days with Lissajous feedback indicating the integrated position of both arms, or with visual or auditory rhythmic feedback reflecting the relative timing of the movement. The results showed diverse performance change after practice when the feedback was removed between Lissajous and the other two rhythmic groups, indicating that the guidance effect may be modulated by the type of information provided during practice. Moreover, significant performance improvement in the dual-task condition where the irregular rhythm counting task was applied as a secondary task also suggested that lower involvement of conscious control may result in better performance in bimanual coordination. PMID:26895286

Bimanual Coordination Learning with Different Augmented Feedback Modalities and Information Types.

PubMed

Chiou, Shiau-Chuen; Chang, Erik Chihhung

2016-01-01

Previous studies have shown that bimanual coordination learning is more resistant to the removal of augmented feedback when acquired with auditory than with visual channel. However, it is unclear whether this differential "guidance effect" between feedback modalities is due to enhanced sensorimotor integration via the non-dominant auditory channel or strengthened linkage to kinesthetic information under rhythmic input. The current study aimed to examine how modalities (visual vs. auditory) and information types (continuous visuospatial vs. discrete rhythmic) of concurrent augmented feedback influence bimanual coordination learning. Participants either learned a 90°-out-of-phase pattern for three consecutive days with Lissajous feedback indicating the integrated position of both arms, or with visual or auditory rhythmic feedback reflecting the relative timing of the movement. The results showed diverse performance change after practice when the feedback was removed between Lissajous and the other two rhythmic groups, indicating that the guidance effect may be modulated by the type of information provided during practice. Moreover, significant performance improvement in the dual-task condition where the irregular rhythm counting task was applied as a secondary task also suggested that lower involvement of conscious control may result in better performance in bimanual coordination.

A spatial error model with continuous random effects and an application to growth convergence

NASA Astrophysics Data System (ADS)

Laurini, Márcio Poletti

2017-10-01

We propose a spatial error model with continuous random effects based on Matérn covariance functions and apply this model for the analysis of income convergence processes (β -convergence). The use of a model with continuous random effects permits a clearer visualization and interpretation of the spatial dependency patterns, avoids the problems of defining neighborhoods in spatial econometrics models, and allows projecting the spatial effects for every possible location in the continuous space, circumventing the existing aggregations in discrete lattice representations. We apply this model approach to analyze the economic growth of Brazilian municipalities between 1991 and 2010 using unconditional and conditional formulations and a spatiotemporal model of convergence. The results indicate that the estimated spatial random effects are consistent with the existence of income convergence clubs for Brazilian municipalities in this period.

A Two-Phase Model of Resource Allocation in Visual Working Memory

ERIC Educational Resources Information Center

Ye, Chaoxiong; Hu, Zhonghua; Li, Hong; Ristaniemi, Tapani; Liu, Qiang; Liu, Taosheng

2017-01-01

Two broad theories of visual working memory (VWM) storage have emerged from current research, a discrete slot-based theory and a continuous resource theory. However, neither the discrete slot-based theory or continuous resource theory clearly stipulates how the mental commodity for VWM (discrete slot or continuous resource) is allocated.…

Serial dependence promotes object stability during occlusion

PubMed Central

Liberman, Alina; Zhang, Kathy; Whitney, David

2016-01-01

Object identities somehow appear stable and continuous over time despite eye movements, disruptions in visibility, and constantly changing visual input. Recent results have demonstrated that the perception of orientation, numerosity, and facial identity is systematically biased (i.e., pulled) toward visual input from the recent past. The spatial region over which current orientations or face identities are pulled by previous orientations or identities, respectively, is known as the continuity field, which is temporally tuned over the past several seconds (Fischer & Whitney, 2014). This perceptual pull could contribute to the visual stability of objects over short time periods, but does it also address how perceptual stability occurs during visual discontinuities? Here, we tested whether the continuity field helps maintain perceived object identity during occlusion. Specifically, we found that the perception of an oriented Gabor that emerged from behind an occluder was significantly pulled toward the random (and unrelated) orientation of the Gabor that was seen entering the occluder. Importantly, this serial dependence was stronger for predictable, continuously moving trajectories, compared to unpredictable ones or static displacements. This result suggests that our visual system takes advantage of expectations about a stable world, helping to maintain perceived object continuity despite interrupted visibility. PMID:28006066

Continuous Symmetry and Chemistry Teachers: Learning Advanced Chemistry Content through Novel Visualization Tools

ERIC Educational Resources Information Center

Tuvi-Arad, Inbal; Blonder, Ron

2010-01-01

In this paper we describe the learning process of a group of experienced chemistry teachers in a specially designed workshop on molecular symmetry and continuous symmetry. The workshop was based on interactive visualization tools that allow molecules and their symmetry elements to be rotated in three dimensions. The topic of continuous symmetry is…

Are visual cue masking and removal techniques equivalent for studying perceptual skills in sport?

PubMed

Mecheri, Sami; Gillet, Eric; Thouvarecq, Regis; Leroy, David

2011-01-01

The spatial-occlusion paradigm makes use of two techniques (masking and removing visual cues) to provide information about the anticipatory cues used by viewers. The visual scene resulting from the removal technique appears to be incongruous, but the assumed equivalence of these two techniques is spreading. The present study was designed to address this issue by combining eye-movement recording with the two types of occlusion (removal versus masking) in a tennis serve-return task. Response accuracy and decision onsets were analysed. The results indicated that subjects had longer reaction times under the removal condition, with an identical proportion of correct responses. Also, the removal technique caused the subjects to rely on atypical search patterns. Our findings suggest that, when the removal technique was used, viewers were unable to systematically count on stored memories to help them accomplish the interception task. The persistent failure to question some of the assumptions about the removal technique in applied visual research is highlighted, and suggestions for continued use of the masking technique are advanced.

Evaluation of tactual displays for flight control

NASA Technical Reports Server (NTRS)

Levison, W. H.; Tanner, R. B.; Triggs, T. J.

1973-01-01

Manual tracking experiments were conducted to determine the suitability of tactual displays for presenting flight-control information in multitask situations. Although tracking error scores are considerably greater than scores obtained with a continuous visual display, preliminary results indicate that inter-task interference effects are substantially less with the tactual display in situations that impose high visual scanning workloads. The single-task performance degradation found with the tactual display appears to be a result of the coding scheme rather than the use of the tactual sensory mode per se. Analysis with the state-variable pilot/vehicle model shows that reliable predictions of tracking errors can be obtained for wide-band tracking systems once the pilot-related model parameters have been adjusted to reflect the pilot-display interaction.

How uncommon is tickertaping? Prevalence and characteristics of seeing the words you hear.

PubMed

Holm, Silje; Eilertsen, Thomas; Price, Mark C

2015-01-01

Tickertape experience is the subjective phenomenon of routinely visualizing the orthographic appearance of words that one hears, speaks, or thinks, like mental subtitles in the mind's eye. It has been observed in grapheme-color synesthetes, whose letter visualizations are colored, but has been very little studied. We report a survey, among 425 Norwegian adults from varied sub-samples, of the prevalence, character, and associated skills of tickertaping. Our questionnaire was designed to reflect different degrees of automaticity of the experience. While strongly automatic tickertaping appeared rare (n = 6; CI95 = 0.6% to 3.2% of sample), lesser degrees of text visualization were reported by more than half of respondents, indicating a continuity between extreme tickertaping and normal cognition. Tickertaping was not strongly associated with greater awareness of an inner voice while reading silently. We also found no strong evidence that tickertapers are unusually likely to self-report skill in rapidly enumerating heard words, or in backward spelling and backward speaking, despite the fact that these skills have been observed in single-case studies of tickertapers. The qualitative character of tickertaping varied among respondents, and included negative experiences. However visualization of letters was predominantly uncolored, indicating that tickertaping is a phenomenon in its own right and not just a subset of grapheme-color synesthesia. We suggest tickertaping is an explicit expression of the close interconnection between phonemic and graphemic representations of words which, for reasons we do not yet understand, manifests as visual imagery with a varying degree of automaticity.

How uncommon is tickertaping? Prevalence and characteristics of seeing the words you hear

PubMed Central

Holm, Silje; Eilertsen, Thomas; Price, Mark C.

2015-01-01

Tickertape experience is the subjective phenomenon of routinely visualizing the orthographic appearance of words that one hears, speaks, or thinks, like mental subtitles in the mind’s eye. It has been observed in grapheme-color synesthetes, whose letter visualizations are colored, but has been very little studied. We report a survey, among 425 Norwegian adults from varied sub-samples, of the prevalence, character, and associated skills of tickertaping. Our questionnaire was designed to reflect different degrees of automaticity of the experience. While strongly automatic tickertaping appeared rare (n = 6; CI95 = 0.6% to 3.2% of sample), lesser degrees of text visualization were reported by more than half of respondents, indicating a continuity between extreme tickertaping and normal cognition. Tickertaping was not strongly associated with greater awareness of an inner voice while reading silently. We also found no strong evidence that tickertapers are unusually likely to self-report skill in rapidly enumerating heard words, or in backward spelling and backward speaking, despite the fact that these skills have been observed in single-case studies of tickertapers. The qualitative character of tickertaping varied among respondents, and included negative experiences. However visualization of letters was predominantly uncolored, indicating that tickertaping is a phenomenon in its own right and not just a subset of grapheme-color synesthesia. We suggest tickertaping is an explicit expression of the close interconnection between phonemic and graphemic representations of words which, for reasons we do not yet understand, manifests as visual imagery with a varying degree of automaticity. PMID:25951376

The aftermath of memory retrieval for recycling visual working memory representations.

PubMed

Park, Hyung-Bum; Zhang, Weiwei; Hyun, Joo-Seok

2017-07-01

We examined the aftermath of accessing and retrieving a subset of information stored in visual working memory (VWM)-namely, whether detection of a mismatch between memory and perception can impair the original memory of an item while triggering recognition-induced forgetting for the remaining, untested items. For this purpose, we devised a consecutive-change detection task wherein two successive testing probes were displayed after a single set of memory items. Across two experiments utilizing different memory-testing methods (whole vs. single probe), we observed a reliable pattern of poor performance in change detection for the second test when the first test had exhibited a color change. The impairment after a color change was evident even when the same memory item was repeatedly probed; this suggests that an attention-driven, salient visual change made it difficult to reinstate the previously remembered item. The second change detection, for memory items untested during the first change detection, was also found to be inaccurate, indicating that recognition-induced forgetting had occurred for the unprobed items in VWM. In a third experiment, we conducted a task that involved change detection plus continuous recall, wherein a memory recall task was presented after the change detection task. The analyses of the distributions of recall errors with a probabilistic mixture model revealed that the memory impairments from both visual changes and recognition-induced forgetting are explained better by the stochastic loss of memory items than by their degraded resolution. These results indicate that attention-driven visual change and recognition-induced forgetting jointly influence the "recycling" of VWM representations.

Neurophysiology underlying influence of stimulus reliability on audiovisual integration.

PubMed

Shatzer, Hannah; Shen, Stanley; Kerlin, Jess R; Pitt, Mark A; Shahin, Antoine J

2018-01-24

We tested the predictions of the dynamic reweighting model (DRM) of audiovisual (AV) speech integration, which posits that spectrotemporally reliable (informative) AV speech stimuli induce a reweighting of processing from low-level to high-level auditory networks. This reweighting decreases sensitivity to acoustic onsets and in turn increases tolerance to AV onset asynchronies (AVOA). EEG was recorded while subjects watched videos of a speaker uttering trisyllabic nonwords that varied in spectrotemporal reliability and asynchrony of the visual and auditory inputs. Subjects judged the stimuli as in-sync or out-of-sync. Results showed that subjects exhibited greater AVOA tolerance for non-blurred than blurred visual speech and for less than more degraded acoustic speech. Increased AVOA tolerance was reflected in reduced amplitude of the P1-P2 auditory evoked potentials, a neurophysiological indication of reduced sensitivity to acoustic onsets and successful AV integration. There was also sustained visual alpha band (8-14 Hz) suppression (desynchronization) following acoustic speech onsets for non-blurred vs. blurred visual speech, consistent with continuous engagement of the visual system as the speech unfolds. The current findings suggest that increased spectrotemporal reliability of acoustic and visual speech promotes robust AV integration, partly by suppressing sensitivity to acoustic onsets, in support of the DRM's reweighting mechanism. Increased visual signal reliability also sustains the engagement of the visual system with the auditory system to maintain alignment of information across modalities. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

[Transient charles bonnet syndrome after excision of a right occipital meningioma: a case report].

PubMed

Arai, Takao; Hasegawa, Yuzuru; Tanaka, Toshihide; Kato, Naoki; Watanabe, Mitsuyoshi; Nakamura, Aya; Murayama, Yuichi

2014-05-01

Charles Bonnet syndrome is a condition characterized by visual hallucinations. These simple or complex visual hallucinations are more common in elderly individuals with impaired peripheral vision. The current report describes a case of transient Charles Bonnet syndrome appearing after the removal of a meningioma. The patient was a 61-year-old man who already had impaired visual acuity due to diabetic retinopathy. Brain MRI revealed a cystic tumor severely compressing the right occipital lobe. Starting on day 2 postoperatively, the patient was troubled by recurring visual hallucinations involving people, flowers, pictures, and familiar settings(the train and a coffee shop). These continued for 3.5 months. This period roughly coincided with the time for the occipital lobe to recover from the compression caused by the tumor, a fact that was confirmed by several MRI scans. ¹²³I-IMP SPECT performed 1 month after the surgical operation showed an area of hypoperfusion in the right parieto-occipital lobe. Based on the patient's clinical course and MRI findings, the mechanism of onset of visual hallucinations in this patient was put forward. The release of pressure in the brain by tumor removal and subsequent recovery changed the blood flow to the brain. This triggered visual hallucinations in the patient, who was already predisposed to developing Charles Bonnet syndrome because of diabetic retinopathy. This case is interesting since it indicates that central neurological factors, as well as visual deficits, may induce the appearance of visual hallucinations in Charles Bonnet syndrome.

A special role for binocular visual input during development and as a component of occlusion therapy for treatment of amblyopia.

PubMed

Mitchell, Donald E

2008-01-01

To review work on animal models of deprivation amblyopia that points to a special role for binocular visual input in the development of spatial vision and as a component of occlusion (patching) therapy for amblyopia. The studies reviewed employ behavioural methods to measure the effects of various early experiential manipulations on the development of the visual acuity of the two eyes. Short periods of concordant binocular input, if continuous, can offset much longer daily periods of monocular deprivation to allow the development of normal visual acuity in both eyes. It appears that the visual system does not weigh all visual input equally in terms of its ability to impact on the development of vision but instead places greater weight on concordant binocular exposure. Experimental models of patching therapy for amblyopia imposed on animals in which amblyopia had been induced by a prior period of early monocular deprivation, indicate that the benefits of patching therapy may be only temporary and decline rapidly after patching is discontinued. However, when combined with critical amounts of binocular visual input each day, the benefits of patching can be both heightened and made permanent. Taken together with demonstrations of retained binocular connections in the visual cortex of monocularly deprived animals, a strong argument is made for inclusion of specific training of stereoscopic vision for part of the daily periods of binocular exposure that should be incorporated as part of any patching protocol for amblyopia.

Visual cortex responses reflect temporal structure of continuous quasi-rhythmic sensory stimulation.

PubMed

Keitel, Christian; Thut, Gregor; Gross, Joachim

2017-02-01

Neural processing of dynamic continuous visual input, and cognitive influences thereon, are frequently studied in paradigms employing strictly rhythmic stimulation. However, the temporal structure of natural stimuli is hardly ever fully rhythmic but possesses certain spectral bandwidths (e.g. lip movements in speech, gestures). Examining periodic brain responses elicited by strictly rhythmic stimulation might thus represent ideal, yet isolated cases. Here, we tested how the visual system reflects quasi-rhythmic stimulation with frequencies continuously varying within ranges of classical theta (4-7Hz), alpha (8-13Hz) and beta bands (14-20Hz) using EEG. Our findings substantiate a systematic and sustained neural phase-locking to stimulation in all three frequency ranges. Further, we found that allocation of spatial attention enhances EEG-stimulus locking to theta- and alpha-band stimulation. Our results bridge recent findings regarding phase locking ("entrainment") to quasi-rhythmic visual input and "frequency-tagging" experiments employing strictly rhythmic stimulation. We propose that sustained EEG-stimulus locking can be considered as a continuous neural signature of processing dynamic sensory input in early visual cortices. Accordingly, EEG-stimulus locking serves to trace the temporal evolution of rhythmic as well as quasi-rhythmic visual input and is subject to attentional bias. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Development of visual cortical function in infant macaques: A BOLD fMRI study

PubMed Central

Meeson, Alan; Munk, Matthias H. J.; Kourtzi, Zoe; Movshon, J. Anthony; Logothetis, Nikos K.; Kiorpes, Lynne

2017-01-01

Functional brain development is not well understood. In the visual system, neurophysiological studies in nonhuman primates show quite mature neuronal properties near birth although visual function is itself quite immature and continues to develop over many months or years after birth. Our goal was to assess the relative development of two main visual processing streams, dorsal and ventral, using BOLD fMRI in an attempt to understand the global mechanisms that support the maturation of visual behavior. Seven infant macaque monkeys (Macaca mulatta) were repeatedly scanned, while anesthetized, over an age range of 102 to 1431 days. Large rotating checkerboard stimuli induced BOLD activation in visual cortices at early ages. Additionally we used static and dynamic Glass pattern stimuli to probe BOLD responses in primary visual cortex and two extrastriate areas: V4 and MT-V5. The resulting activations were analyzed with standard GLM and multivoxel pattern analysis (MVPA) approaches. We analyzed three contrasts: Glass pattern present/absent, static/dynamic Glass pattern presentation, and structured/random Glass pattern form. For both GLM and MVPA approaches, robust coherent BOLD activation appeared relatively late in comparison to the maturation of known neuronal properties and the development of behavioral sensitivity to Glass patterns. Robust differential activity to Glass pattern present/absent and dynamic/static stimulus presentation appeared first in V1, followed by V4 and MT-V5 at older ages; there was no reliable distinction between the two extrastriate areas. A similar pattern of results was obtained with the two analysis methods, although MVPA analysis showed reliable differential responses emerging at later ages than GLM. Although BOLD responses to large visual stimuli are detectable, our results with more refined stimuli indicate that global BOLD activity changes as behavioral performance matures. This reflects an hierarchical development of the visual pathways. Since fMRI BOLD reflects neural activity on a population level, our results indicate that, although individual neurons might be adult-like, a longer maturation process takes place on a population level. PMID:29145469

Visual outcomes of phacoemulsification cataract surgery in horses: 1990-2013.

PubMed

Brooks, Dennis E; Plummer, Caryn E; Carastro, Susan M; Utter, Mary E

2014-07-01

To evaluate the long-term visual outcome of phacoemulsification lens extraction surgery in foals and horses and identify any unique postoperative complications that affect the visual outcome. This is a retrospective medical records study of phacoemulsification cataract surgery in 95 foals and horses from 1990 to 2013. Cataracts were removed by phacoemulsification from 111 eyes of 95 horses ranging in age from 22 days to 26 years (average 8.0 ± 5.7 years). Forty-four of the 95 animals were foals (46.3%). Sixteen horses or foals had surgery bilaterally. One hundred and two eyes were blind preoperatively with 97 eyes (95.1%) having evidence of vision immediately postoperatively. Ninety of the 95 horses (94.7%) regained vision in the immediate postoperative period. Five horses did not recover vision postoperatively. Twenty-four horses had cataracts associated with equine recurrent uveitis (ERU). Trauma was noted as the cause of cataract in 10 horses, and no specific cause for the cataract identified in 61 horses. The combined visual outcome data from horses with all types of cataracts (n = 95) found 83 (87.3%) horses to be visual ≤1 month postoperatively, 47 (49.4%) horses visual for >1-6 months postoperatively, 33 (34.7%) horses visual from >6 to 12 months postoperatively, and 25 horses (26.3%) visual >24 months postoperatively. The results of phacoemulsification cataract surgery in horses indicate at least 26.3% of horses are still visual and able to continue their natural activity for 2 years or more postoperatively. © 2014 American College of Veterinary Ophthalmologists.

Invariant visual object recognition: a model, with lighting invariance.

PubMed

Rolls, Edmund T; Stringer, Simon M

2006-01-01

How are invariant representations of objects formed in the visual cortex? We describe a neurophysiological and computational approach which focusses on a feature hierarchy model in which invariant representations can be built by self-organizing learning based on the statistics of the visual input. The model can use temporal continuity in an associative synaptic learning rule with a short term memory trace, and/or it can use spatial continuity in Continuous Transformation learning. The model of visual processing in the ventral cortical stream can build representations of objects that are invariant with respect to translation, view, size, and in this paper we show also lighting. The model has been extended to provide an account of invariant representations in the dorsal visual system of the global motion produced by objects such as looming, rotation, and object-based movement. The model has been extended to incorporate top-down feedback connections to model the control of attention by biased competition in for example spatial and object search tasks. The model has also been extended to account for how the visual system can select single objects in complex visual scenes, and how multiple objects can be represented in a scene.

Precipitated withdrawal from nicotine reduces reinforcing effects of a visual stimulus for rats.

PubMed

Weaver, Matthew T; Sweitzer, Maggie; Coddington, Sarah; Sheppard, Jaimee; Verdecchia, Nicole; Caggiula, Anthony R; Sved, Alan F; Donny, Eric C

2012-07-01

Research has identified at least two positive reinforcement-related effects of nicotine: (a) primary reinforcement and (b) enhancement of reinforcement from concurrently available stimuli. Prior examples of the reinforcement-enhancing effects with rats showed that repeated, intermittent nicotine exposure increased responding for non-nicotine reinforcers, and this effect remained robust over several weeks. However, the effects of continuous nicotine exposure on responding for a non-nicotine reinforcer are unknown, as are the effects of abruptly withdrawing continuous nicotine on behavior maintained by the same reinforcer. Lever pressing for a visual reinforcer under a fixed ratio schedule was assessed while rats were maintained on a chronic, continuous infusion of nicotine (3.16 mg/kg/day; osmotic minipump). The effects of precipitated withdrawal on responding, following 16 days of continuous nicotine exposure, were assessed by pre-session subcutaneous injections of mecamylamine (1.0 mg/kg). Continuous nicotine initially increased active responding for the visual reinforcer; however, continued exposure resulted in an attenuation of this effect. Precipitated withdrawal from nicotine resulted in a significant decline in active responding. The initial increase in responding for the visual reinforcer with chronic nicotine exposure is consistent with prior research showing that intermittent exposure to nicotine acts as a reinforcement enhancer. However, the attenuation of this enhancement following prolonged nicotine exposure is in contrast with the persistent effects previously reported. Finally, the decrease in visual reinforcers below control levels (nicotine-naive animals) following nicotine withdrawal highlights a potential for affective withdrawal, which may serve as a motive for continued nicotine use.

Figure-ground processing during fixational saccades in V1: indication for higher-order stability.

PubMed

Gilad, Ariel; Pesoa, Yair; Ayzenshtat, Inbal; Slovin, Hamutal

2014-02-26

In a typical visual scene we continuously perceive a "figure" that is segregated from the surrounding "background" despite ongoing microsaccades and small saccades that are performed when attempting fixation (fixational saccades [FSs]). Previously reported neuronal correlates of figure-ground (FG) segregation in the primary visual cortex (V1) showed enhanced activity in the "figure" along with suppressed activity in the noisy "background." However, it is unknown how this FG modulation in V1 is affected by FSs. To investigate this question, we trained two monkeys to detect a contour embedded in a noisy background while simultaneously imaging V1 using voltage-sensitive dyes. During stimulus presentation, the monkeys typically performed 1-3 FSs, which displaced the contour over the retina. Using eye position and a 2D analytical model to map the stimulus onto V1, we were able to compute FG modulation before and after each FS. On the spatial cortical scale, we found that, after each FS, FG modulation follows the stimulus retinal displacement and "hops" within the V1 retinotopic map, suggesting visual instability. On the temporal scale, FG modulation is initiated in the new retinotopic position before it disappeared from the old retinotopic position. Moreover, the FG modulation developed faster after an FS, compared with after stimulus onset, which may contribute to visual stability of FG segregation, along the timeline of stimulus presentation. Therefore, despite spatial discontinuity of FG modulation in V1, the higher-order stability of FG modulation along time may enable our stable and continuous perception.

A stroboscopic technique for using CCD cameras in flow visualization systems for continuous viewing and stop action photography

NASA Technical Reports Server (NTRS)

Franke, John M.; Rhodes, David B.; Jones, Stephen B.; Dismond, Harriet R.

1992-01-01

A technique for synchronizing a pulse light source to charge coupled device cameras is presented. The technique permits the use of pulse light sources for continuous as well as stop action flow visualization. The technique has eliminated the need to provide separate lighting systems at facilities requiring continuous and stop action viewing or photography.

Forces and energetics of intermittent swimming

NASA Astrophysics Data System (ADS)

Floryan, Daniel; Van Buren, Tyler; Smits, Alexander J.

2017-08-01

Experiments are reported on intermittent swimming motions. Water tunnel experiments on a nominally two-dimensional pitching foil show that the mean thrust and power scale linearly with the duty cycle, from a value of 0.2 all the way up to continuous motions, indicating that individual bursts of activity in intermittent motions are independent of each other. This conclusion is corroborated by particle image velocimetry (PIV) flow visualizations, which show that the main vortical structures in the wake do not change with duty cycle. The experimental data also demonstrate that intermittent motions are generally energetically advantageous over continuous motions. When metabolic energy losses are taken into account, this conclusion is maintained for metabolic power fractions less than 1.

Super-resolution pupil filtering for visual performance enhancement using adaptive optics

NASA Astrophysics Data System (ADS)

Zhao, Lina; Dai, Yun; Zhao, Junlei; Zhou, Xiaojun

2018-05-01

Ocular aberration correction can significantly improve visual function of the human eye. However, even under ideal aberration correction conditions, pupil diffraction restricts the resolution of retinal images. Pupil filtering is a simple super-resolution (SR) method that can overcome this diffraction barrier. In this study, a 145-element piezoelectric deformable mirror was used as a pupil phase filter because of its programmability and high fitting accuracy. Continuous phase-only filters were designed based on Zernike polynomial series and fitted through closed-loop adaptive optics. SR results were validated using double-pass point spread function images. Contrast sensitivity was further assessed to verify the SR effect on visual function. An F-test was conducted for nested models to statistically compare different CSFs. These results indicated CSFs for the proposed SR filter were significantly higher than the diffraction correction (p < 0.05). As such, the proposed filter design could provide useful guidance for supernormal vision optical correction of the human eye.

The Riddle of Style Changes in the Visual Arts after Interference with the Right Brain

PubMed Central

Blanke, Olaf; Pasqualini, Isabella

2011-01-01

We here analyze the paintings and films of several visual artists, who suffered from a well-defined neuropsychological deficit, visuo-spatial hemineglect, following vascular stroke to the right brain. In our analysis we focus in particular on the oeuvre of Lovis Corinth and Luchino Visconti as both major artists continued to be highly productive over many years after their right brain damage. We analyzed their post-stroke paintings and films, indicate several aspects that differ from their pre-stroke work (omissions, use of color, perseveration, deformation), and propose–although both artists come from different times, countries, genres, and styles–that their post-stroke oeuvre reveals important similarities in style. We argue that these changes may be associated with visuo-spatial hemineglect and the right brain. We discuss future avenues of how the neuropsychological investigation of visual artists with and without neglect may allow us to investigate the relationship between brain and art. PMID:22232586

Can perceptual grouping unfold in the absence of awareness? Comparing grouping during continuous flash suppression and sandwich masking.

PubMed

Kimchi, Ruth; Devyatko, Dina; Sabary, Shahar

2018-04-01

In this study we examined whether grouping by luminance similarity and grouping by connectedness can occur in the absence of visual awareness, using a priming paradigm and two methods to render the prime invisible, CFS and sandwich masking under matched conditions. For both groupings, significant response priming effects were observed when the prime was reported invisible under sandwich masking, but none were obtained under CFS. These results provide evidence for unconscious grouping, converging with previous findings showing that visual awareness is not essential for certain perceptual organization processes to occur. They are also consistent with findings indicating that processing during CFS is limited, and suggest the involvement of higher visual areas in perceptual organization. Moreover, these results demonstrate that whether a process can occur without awareness is dependent on the level at which the suppression induced by the method used for rendering the stimulus inaccessible to awareness takes place. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of prolonged bedrest and plus Gz acceleration on peripheral visual response time

NASA Technical Reports Server (NTRS)

Haines, R. F.

1973-01-01

Peripheral visual response time changes during +G sub z acceleration following fourteen days of bedrest are considered as well as what effect prolonged bedrest has upon this response. Eighteen test lights, placed 10 deg are apart along the horizontal meridian of the subject's field of view, were presented in a random sequence. The subject was instructed to press a button as soon as a light appeared. Response time testing occurred periodically during bedrest and continuously during centrifugation testing. The results indicate that: (1) mean response time is significantly longer to stimuli imaged in the far periphery than to stimuli imaged closer to the line of sight; (2) mean response time at each stimulus position tends to be longer at plateau g than during the preacceleration baseline period; (3) mean response time tends to lengthen as the g level is increased; (4) peripheral visual response time during +G sub x acceleration at 2, 3.2, and 3.8 g was not a reliable advanced indicator that blackout was going to occur; and (5) the subject's field of view collapsed rapidly just before blackout. Bedrest data showed that the distribution of response times to stimuli imaged across the subject's horizontal retinal meridian remained remarkably constant from day to day during both the bedrest and recovery periods.

Visual flow scene effects on the somatogravic illusion in non-pilots.

PubMed

Eriksson, Lars; von Hofsten, Claes; Tribukait, Arne; Eiken, Ola; Andersson, Peter; Hedström, Johan

2008-09-01

The somatogravic illusion (SGI) is easily broken when the pilot looks out the aircraft window during daylight flight, but it has proven difficult to break or even reduce the SGI in non-pilots in simulators using synthetic visual scenes. Could visual-flow scenes that accommodate compensatory head movement reduce the SGI in naive subjects? We investigated the effects of visual cues on the SGI induced by a human centrifuge. The subject was equipped with a head-tracked, head-mounted display (HMD) and was seated in a fixed gondola facing the center of rotation. The angular velocity of the centrifuge increased from near zero until a 0.57-G centripetal acceleration was attained, resulting in a tilt of the gravitoinertial force vector, corresponding to a pitch-up of 30 degrees. The subject indicated perceived horizontal continuously by means of a manual adjustable-plate system. We performed two experiments with within-subjects designs. In Experiment 1, the subjects (N = 13) viewed a darkened HMD and a presentation of simple visual flow beneath a horizon. In Experiment 2, the subjects (N = 12) viewed a darkened HMD, a scene including symbology superimposed on simple visual flow and horizon, and this scene without visual flow (static). In Experiment 1, visual flow reduced the SGI from 12.4 +/- 1.4 degrees (mean +/- SE) to 8.7 +/- 1.5 degrees. In Experiment 2, the SGI was smaller in the visual flow condition (9.3 +/- 1.8 degrees) than with the static scene (13.3 +/- 1.7 degrees) and without HMD presentation (14.5 +/- 2.3 degrees), respectively. It is possible to reduce the SGI in non-pilots by means of a synthetic horizon and simple visual flow conveyed by a head-tracked HMD. This may reflect the power of a more intuitive display for reducing the SGI.

Ranibizumab (Lucentis) in neovascular age-related macular degeneration: evidence from clinical trials.

PubMed

Mitchell, P; Korobelnik, J-F; Lanzetta, P; Holz, F G; Prünte, C; Schmidt-Erfurth, U; Tano, Y; Wolf, S

2010-01-01

Neovascular age-related macular degeneration (AMD) has a poor prognosis if left untreated, frequently resulting in legal blindness. Ranibizumab is approved for treating neovascular AMD. However, further guidance is needed to assist ophthalmologists in clinical practice to optimise treatment outcomes. An international retina expert panel assessed evidence available from prospective, multicentre studies evaluating different ranibizumab treatment schedules (ANCHOR, MARINA, PIER, SAILOR, SUSTAIN and EXCITE) and a literature search to generate evidence-based and consensus recommendations for treatment indication and assessment, retreatment and monitoring. Ranibizumab is indicated for choroidal neovascular lesions with active disease, the clinical parameters of which are outlined. Treatment initiation with three consecutive monthly injections, followed by continued monthly injections, has provided the best visual-acuity outcomes in pivotal clinical trials. If continued monthly injections are not feasible after initiation, a flexible strategy appears viable, with monthly monitoring of lesion activity recommended. Initiation regimens of fewer than three injections have not been assessed. Continuous careful monitoring with flexible retreatment may help avoid vision loss recurring. Standardised biomarkers need to be determined. Evidence-based guidelines will help to optimise treatment outcomes with ranibizumab in neovascular AMD.

Sorting points into neighborhoods (SPIN): data analysis and visualization by ordering distance matrices.

PubMed

Tsafrir, D; Tsafrir, I; Ein-Dor, L; Zuk, O; Notterman, D A; Domany, E

2005-05-15

We introduce a novel unsupervised approach for the organization and visualization of multidimensional data. At the heart of the method is a presentation of the full pairwise distance matrix of the data points, viewed in pseudocolor. The ordering of points is iteratively permuted in search of a linear ordering, which can be used to study embedded shapes. Several examples indicate how the shapes of certain structures in the data (elongated, circular and compact) manifest themselves visually in our permuted distance matrix. It is important to identify the elongated objects since they are often associated with a set of hidden variables, underlying continuous variation in the data. The problem of determining an optimal linear ordering is shown to be NP-Complete, and therefore an iterative search algorithm with O(n3) step-complexity is suggested. By using sorting points into neighborhoods, i.e. SPIN to analyze colon cancer expression data we were able to address the serious problem of sample heterogeneity, which hinders identification of metastasis related genes in our data. Our methodology brings to light the continuous variation of heterogeneity--starting with homogeneous tumor samples and gradually increasing the amount of another tissue. Ordering the samples according to their degree of contamination by unrelated tissue allows the separation of genes associated with irrelevant contamination from those related to cancer progression. Software package will be available for academic users upon request.

Perceptual integration of motion and form information: evidence of parallel-continuous processing.

PubMed

von Mühlenen, A; Müller, H J

2000-04-01

In three visual search experiments, the processes involved in the efficient detection of motion-form conjunction targets were investigated. Experiment 1 was designed to estimate the relative contributions of stationary and moving nontargets to the search rate. Search rates were primarily determined by the number of moving nontargets; stationary nontargets sharing the target form also exerted a significant effect, but this was only about half as strong as that of moving nontargets; stationary nontargets not sharing the target form had little influence. In Experiments 2 and 3, the effects of display factors influencing the visual (form) quality of moving items (movement speed and item size) were examined. Increasing the speed of the moving items (> 1.5 degrees/sec) facilitated target detection when the task required segregation of the moving from the stationary items. When no segregation was necessary, increasing the movement speed impaired performance: With large display items, motion speed had little effect on target detection, but with small items, search efficiency declined when items moved faster than 1.5 degrees/sec. This pattern indicates that moving nontargets exert a strong effect on the search rate (Experiment 1) because of the loss of visual quality for moving items above a certain movement speed. A parallel-continuous processing account of motion-form conjunction search is proposed, which combines aspects of Guided Search (Wolfe, 1994) and attentional engagement theory (Duncan & Humphreys, 1989).

The absence or temporal offset of visual feedback does not influence adaptation to novel movement dynamics.

PubMed

McKenna, Erin; Bray, Laurence C Jayet; Zhou, Weiwei; Joiner, Wilsaan M

2017-10-01

Delays in transmitting and processing sensory information require correctly associating delayed feedback to issued motor commands for accurate error compensation. The flexibility of this alignment between motor signals and feedback has been demonstrated for movement recalibration to visual manipulations, but the alignment dependence for adapting movement dynamics is largely unknown. Here we examined the effect of visual feedback manipulations on force-field adaptation. Three subject groups used a manipulandum while experiencing a lag in the corresponding cursor motion (0, 75, or 150 ms). When the offset was applied at the start of the session (continuous condition), adaptation was not significantly different between groups. However, these similarities may be due to acclimation to the offset before motor adaptation. We tested additional subjects who experienced the same delays concurrent with the introduction of the perturbation (abrupt condition). In this case adaptation was statistically indistinguishable from the continuous condition, indicating that acclimation to feedback delay was not a factor. In addition, end-point errors were not significantly different across the delay or onset conditions, but end-point correction (e.g., deceleration duration) was influenced by the temporal offset. As an additional control, we tested a group of subjects who performed without visual feedback and found comparable movement adaptation results. These results suggest that visual feedback manipulation (absence or temporal misalignment) does not affect adaptation to novel dynamics, independent of both acclimation and perceptual awareness. These findings could have implications for modeling how the motor system adjusts to errors despite concurrent delays in sensory feedback information. NEW & NOTEWORTHY A temporal offset between movement and distorted visual feedback (e.g., visuomotor rotation) influences the subsequent motor recalibration, but the effects of this offset for altered movement dynamics are largely unknown. Here we examined the influence of 1 ) delayed and 2 ) removed visual feedback on the adaptation to novel movement dynamics. These results contribute to understanding of the control strategies that compensate for movement errors when there is a temporal separation between motion state and sensory information. Copyright © 2017 the American Physiological Society.

BioMon: A Google Earth Based Continuous Biomass Monitoring System (Demo Paper)

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

Vatsavai, Raju

2009-01-01

We demonstrate a Google Earth based novel visualization system for continuous monitoring of biomass at regional and global scales. This system is integrated with a back-end spatiotemporal data mining system that continuously detects changes using high temporal resolution MODIS images. In addition to the visualization, we demonstrate novel query features of the system that provides insights into the current conditions of the landscape.

The Spatial and the Visual in Mental Spatial Reasoning: An Ill-Posed Distinction

NASA Astrophysics Data System (ADS)

Schultheis, Holger; Bertel, Sven; Barkowsky, Thomas; Seifert, Inessa

It is an ongoing and controversial debate in cognitive science which aspects of knowledge humans process visually and which ones they process spatially. Similarly, artificial intelligence (AI) and cognitive science research, in building computational cognitive systems, tended to use strictly spatial or strictly visual representations. The resulting systems, however, were suboptimal both with respect to computational efficiency and cognitive plau sibility. In this paper, we propose that the problems in both research strands stem from a mis conception of the visual and the spatial in mental spatial knowl edge pro cessing. Instead of viewing the visual and the spatial as two clearly separable categories, they should be conceptualized as the extremes of a con tinuous dimension of representation. Regarding psychology, a continuous di mension avoids the need to exclusively assign processes and representations to either one of the cate gories and, thus, facilitates a more unambiguous rating of processes and rep resentations. Regarding AI and cognitive science, the con cept of a continuous spatial / visual dimension provides the possibility of rep re sentation structures which can vary continuously along the spatial / visual di mension. As a first step in exploiting these potential advantages of the pro posed conception we (a) introduce criteria allowing for a non-dichotomic judgment of processes and representations and (b) present an approach towards rep re sentation structures that can flexibly vary along the spatial / visual dimension.

Ocular trauma.

PubMed

Cassen, J H

1997-10-01

A review of the literature was conducted to investigate recent articles about ocular trauma. Eye injuries may be divided into blunt and penetrating types. Males are more affected than females. Evaluation of eye injuries should start with visual acuity and continue with prompt referral to an ophthalmologist as indicated. Medlines search/American Academy of Ophthalmology. Ocular trauma is a frequent reason for emergency room visits. Most injuries stem from sports, recreation, military, occupational, or automotive. Patient education is highly recommended, as well as prevention by use of protective polycarbonate eyewear.

The effect of automated monitoring and real-time prompting on nurses' hand hygiene performance.

PubMed

Levchenko, Alexander I; Boscart, Veronique M; Fernie, Geoff R

2013-10-01

Adequate hand hygiene compliance by healthcare staff is considered an effective method to reduce hospital-acquired infections. The electronic system developed at Toronto Rehabilitation Institute automatically detects hand hygiene opportunities and records hand hygiene actions. It includes an optional visual hand hygiene status indication, generates real-time hand hygiene prompting signals, and enables automated monitoring of individual and aggregated hand hygiene performance. The system was installed on a complex continuous care unit at the entrance to 17 patient rooms and a utility room. A total of 93 alcohol gel and soap dispensers were instrumented and 14 nurses were provided with the personal wearable electronic monitors. The study included three phases with the system operating in three different modes: (1) an inactive mode during the first phase when hand hygiene opportunities and hand hygiene actions were recorded but prompting and visual indication functions were disabled, (2) only hand hygiene status indicators were enabled during the second phase, and (3) both hand hygiene status and real-time hand hygiene prompting signals were enabled during the third phase. Data collection was performed automatically during all of the three phases. The system indicated significantly higher hand hygiene activity rates and compliance during the third phase, with both hand hygiene indication and real-time prompting functions enabled. To increase the efficacy of the technology, its use was supplemented with individual performance reviews of the automatically collected data.

Media/Device Configurations for Platoon Leader Tactical Training

DTIC Science & Technology

1985-02-01

munication and visual communication sig- na ls, VInputs to the The device should simulate the real- Platoon Leader time receipt of all tactical voice...communication, audio and visual battle- field cues, and visual communication signals. 14- Table 4 (Continued) Functional Capability Categories and...battlefield cues, and visual communication signals. 0.8 Receipt of limited tactical voice communication, plus audio and visual battlefield cues, and visual

Social vision: sustained perceptual enhancement of affective facial cues in social anxiety

PubMed Central

McTeague, Lisa M.; Shumen, Joshua R.; Wieser, Matthias J.; Lang, Peter J.; Keil, Andreas

2010-01-01

Heightened perception of facial cues is at the core of many theories of social behavior and its disorders. In the present study, we continuously measured electrocortical dynamics in human visual cortex, as evoked by happy, neutral, fearful, and angry faces. Thirty-seven participants endorsing high versus low generalized social anxiety (upper and lower tertiles of 2,104 screened undergraduates) viewed naturalistic faces flickering at 17.5 Hz to evoke steady-state visual evoked potentials (ssVEPs), recorded from 129 scalp electrodes. Electrophysiological data were evaluated in the time-frequency domain after linear source space projection using the minimum norm method. Source estimation indicated an early visual cortical origin of the face-evoked ssVEP, which showed sustained amplitude enhancement for emotional expressions specifically in individuals with pervasive social anxiety. Participants in the low symptom group showed no such sensitivity, and a correlational analysis across the entire sample revealed a strong relationship between self-reported interpersonal anxiety/avoidance and enhanced visual cortical response amplitude for emotional, versus neutral expressions. This pattern was maintained across the 3500 ms viewing epoch, suggesting that temporally sustained, heightened perceptual bias towards affective facial cues is associated with generalized social anxiety. PMID:20832490

Recognition Decisions From Visual Working Memory Are Mediated by Continuous Latent Strengths.

PubMed

Ricker, Timothy J; Thiele, Jonathan E; Swagman, April R; Rouder, Jeffrey N

2017-08-01

Making recognition decisions often requires us to reference the contents of working memory, the information available for ongoing cognitive processing. As such, understanding how recognition decisions are made when based on the contents of working memory is of critical importance. In this work we examine whether recognition decisions based on the contents of visual working memory follow a continuous decision process of graded information about the correct choice or a discrete decision process reflecting only knowing and guessing. We find a clear pattern in favor of a continuous latent strength model of visual working memory-based decision making, supporting the notion that visual recognition decision processes are impacted by the degree of matching between the contents of working memory and the choices given. Relation to relevant findings and the implications for human information processing more generally are discussed. Copyright © 2016 Cognitive Science Society, Inc.

21 CFR 886.1360 - Visual field laser instrument.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Visual field laser instrument. 886.1360 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1360 Visual field laser instrument. (a) Identification. A visual field laser instrument is an AC-powered device intended to provide...

The Interplay between Nonsymbolic Number and Its Continuous Visual Properties

ERIC Educational Resources Information Center

Gebuis, Titia; Reynvoet, Bert

2012-01-01

To date, researchers investigating nonsymbolic number processes devoted little attention to the visual properties of their stimuli. This is unexpected, as nonsymbolic number is defined by its visual characteristics. When number changes, its visual properties change accordingly. In this study, we investigated the influence of different visual…

21 CFR 886.1360 - Visual field laser instrument.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Visual field laser instrument. 886.1360 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1360 Visual field laser instrument. (a) Identification. A visual field laser instrument is an AC-powered device intended to provide...

21 CFR 886.1360 - Visual field laser instrument.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Visual field laser instrument. 886.1360 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1360 Visual field laser instrument. (a) Identification. A visual field laser instrument is an AC-powered device intended to provide...

21 CFR 886.1360 - Visual field laser instrument.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Visual field laser instrument. 886.1360 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1360 Visual field laser instrument. (a) Identification. A visual field laser instrument is an AC-powered device intended to provide...

33 CFR 175.130 - Visual distress signals accepted.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Visual distress signals accepted... (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.130 Visual distress signals accepted. (a) Any of the following signals, when carried in the number required, can be used to meet the...

33 CFR 175.130 - Visual distress signals accepted.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Visual distress signals accepted... (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.130 Visual distress signals accepted. (a) Any of the following signals, when carried in the number required, can be used to meet the...

33 CFR 175.130 - Visual distress signals accepted.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Visual distress signals accepted... (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.130 Visual distress signals accepted. (a) Any of the following signals, when carried in the number required, can be used to meet the...

Sub aquatic 3D visualization and temporal analysis utilizing ArcGIS online and 3D applications

EPA Science Inventory

We used 3D Visualization tools to illustrate some complex water quality data we’ve been collecting in the Great Lakes. These data include continuous tow data collected from our research vessel the Lake Explorer II, and continuous water quality data collected from an autono...

Defining Visual Communication for a Multi-Media World.

ERIC Educational Resources Information Center

Griffin, Michael

1991-01-01

Explores the role of visual communication and discusses its placement within journalism education. States that educators would do well to dissolve the arbitrary divisions that continue to obstruct a more integrated understanding of visual mass media. (MG)

A novel approach to infection imaging using a synthetic Tc-99m-labeled leukotactic peptide

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

Som, P.; Oster, Z.H.; Sharma, S.

1996-05-01

RMT1, a synthetic peptide binding to PMN and macrophage receptors was labeled with Tc-99m and investigated as a potential imaging agent for abscess and inflammation. Experimental abscesses were induced in rabbits and dogs by turpentine and E.coli injection. After injection of Tc-99m-RMT1 two and twelve day old abscesses were visualized within 20 min. In initial studies, a dose of 30 {mu}g of peptide/3 mCi was used. This amount was subsequently reduced to 1.5 {mu}g peptide with same amount of Tc-99m yielding similar imaging results. Technetium-99m-IgG and Tc-99m-MAG-3 were used as positive and negative controls, respectively. After injection of IgG abscessesmore » were visualized but activity in blood was always higher than in abscess. When using Tc-99m RMT1 rapid abscess visualization and faster blood clearance was observed. The accumulation of RMT1 was monophasic, i.e., following the initial visualization, activity continued to build up continuously for 1{1/2} hr. Tc-99m-MAG3 accumulated initially in abscess, but activity washed out. In dogs, RMT1 blood clearance showed three components: a fast component with t{1/2}=1.9 min, 73%, intermediate t{1/2}=22 min, 24.5% and slow component, t{1/2}=115, 9.5% with 3 hours cumulative urine excretion of 40-51%. RMT1 appears to be more advantageous than currently available methods because of rapidity of imaging, simpler preparation before injection and will probably be less expensive and time consuming compared to labeled WBC. These results indicate that clinical experiments are warranted.« less

Clinical and Laboratory Evaluation of Peripheral Prism Glasses for Hemianopia

PubMed Central

Giorgi, Robert G.; Woods, Russell L.; Peli, Eli

2008-01-01

Purpose Homonymous hemianopia (the loss of vision on the same side in each eye) impairs the ability to navigate and walk safely. We evaluated peripheral prism glasses as a low vision optical device for hemianopia in an extended wearing trial. Methods Twenty-three patients with complete hemianopia (13 right) with neither visual neglect nor cognitive deficit enrolled in the 5-visit study. To expand the horizontal visual field, patients’ spectacles were fitted with both upper and lower Press-On™ Fresnel prism segments (each 40 prism diopters) across the upper and lower portions of the lens on the hemianopic (“blind”) side. Patients were asked to wear these spectacles as much as possible for the duration of the study, which averaged 9 (range: 5 to 13) weeks. Clinical success (continued wear, indicating perceived overall benefit), visual field expansion, perceived direction and perceived quality of life were measured. Results Clinical Success: 14 of 21 (67%) patients chose to continue to wear the peripheral prism glasses at the end of the study (2 patients did not complete the study for non-vision reasons). At long-term follow-up (8 to 51 months), 5 of 12 (42%) patients reported still wearing the device. Visual Field Expansion: Expansion of about 22 degrees in both the upper and lower quadrants was demonstrated for all patients (binocular perimetry, Goldmann V4e). Perceived Direction: Two patients demonstrated a transient adaptation to the change in visual direction produced by the peripheral prism glasses. Quality of Life: At study end, reduced difficulty noticing obstacles on the hemianopic side was reported. Conclusions The peripheral prism glasses provided reported benefits (usually in obstacle avoidance) to 2/3 of the patients completing the study, a very good success rate for a vision rehabilitation device. Possible reasons for long-term discontinuation and limited adaptation of perceived direction are discussed. PMID:19357552

Neural correlates of individual performance differences in resolving perceptual conflict.

PubMed

Labrenz, Franziska; Themann, Maria; Wascher, Edmund; Beste, Christian; Pfleiderer, Bettina

2012-01-01

Attentional mechanisms are a crucial prerequisite to organize behavior. Most situations may be characterized by a 'competition' between salient, but irrelevant stimuli and less salient, relevant stimuli. In such situations top-down and bottom-up mechanisms interact with each other. In the present fMRI study, we examined how interindividual differences in resolving situations of perceptual conflict are reflected in brain networks mediating attentional selection. Doing so, we employed a change detection task in which subjects had to detect luminance changes in the presence and absence of competing distractors. The results show that good performers presented increased activation in the orbitofrontal cortex (BA 11), anterior cingulate (BA 25), inferior parietal lobule (BA 40) and visual areas V2 and V3 but decreased activation in BA 39. This suggests that areas mediating top-down attentional control are stronger activated in this group. Increased activity in visual areas reflects distinct neuronal enhancement relating to selective attentional mechanisms in order to solve the perceptual conflict. Opposed to good performers, brain areas activated by poor performers comprised the left inferior parietal lobule (BA 39) and fronto-parietal and visual regions were continuously deactivated, suggesting that poor performers perceive stronger conflict than good performers. Moreover, the suppression of neural activation in visual areas might indicate a strategy of poor performers to inhibit the processing of the irrelevant non-target feature. These results indicate that high sensitivity in perceptual areas and increased attentional control led to less conflict in stimulus processing and consequently to higher performance in competitive attentional selection.

Immediate and long-term changes of fundus autofluorescence in continuous wave laser lesions of the retina.

PubMed

Framme, Carsten; Roider, Johann

2004-01-01

To determine whether fundus autofluorescence imaging is able to show changes in retinal pigment epithelium (RPE) fluorescence after thermal laser photocoagulation. In vivo imaging of fundus autofluorescence was performed with a scanning laser ophthalmoscope. A laser with a wavelength of 488 nm was used for excitation of the tissue and autofluorescence was detected above 500 nm using a barrier filter. One hundred eight eyes of 87 patients who had had previous laser treatment were monitored. The appearance and size of the laser lesions were documented and correlated to the time of treatment. Immediate changes were observed prospectively in 13 eyes; long-term follow-up was studied retrospectively in 95 eyes. In all patients but one, autofluorescence was decreased in the area of laser lesions 1 hour after laser treatment. After 1 month, previously decreased autofluorescence in all lesions changed to significantly increased autofluorescence, which was stable up to 6 months after treatment. Mixed forms were present approximately 6 to 12 months after treatment, showing a central island of increased autofluorescence surrounded by a ring of decreased autofluorescence. After 1 to 2 years, lesions again changed to complete dark spots, enlarging later on. RPE destruction and subsequent proliferation after continuous wave laser photocoagulation can be visualized noninvasively by autofluorescence imaging. Immediate decreased autofluorescence may indicate acute damage of the RPE, subsequent increased autofluorescence seems to indicate proliferative behavior of the RPE, and final dark spots can indicate RPE atrophy secondary to a denaturation of neurosensory retinal tissue. Thus, autofluorescence can be used in the long-term monitoring of RPE changes after laser treatment. The enlargement of the laser atrophy zone demonstrates the potential risk of visual loss after central laser photocoagulation even years after treatment.

33 CFR 175.110 - Visual distress signals required.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Visual distress signals required... (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.110 Visual distress signals... signals selected from the list in § 175.130 or the alternatives in § 175.135, in the number required, are...

Constructing and Reading Visual Information: Visual Literacy for Library and Information Science Education

ERIC Educational Resources Information Center

Ma, Yan

2015-01-01

This article examines visual literacy education and research for library and information science profession to educate the information professionals who will be able to execute and implement the ACRL (Association of College and Research Libraries) Visual Literacy Competency Standards successfully. It is a continuing call for inclusion of visual…

Cognitive and Developmental Influences in Visual-Motor Integration Skills in Young Children

ERIC Educational Resources Information Center

Decker, Scott L.; Englund, Julia A.; Carboni, Jessica A.; Brooks, Janell H.

2011-01-01

Measures of visual-motor integration skills continue to be widely used in psychological assessments with children. However, the construct validity of many visual-motor integration measures remains unclear. In this study, we investigated the relative contributions of maturation and cognitive skills to the development of visual-motor integration…

33 CFR 175.110 - Visual distress signals required.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Visual distress signals required... (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.110 Visual distress signals... signals selected from the list in § 175.130 or the alternatives in § 175.135, in the number required, are...

33 CFR 175.110 - Visual distress signals required.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Visual distress signals required... (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.110 Visual distress signals... signals selected from the list in § 175.130 or the alternatives in § 175.135, in the number required, are...

33 CFR 175.110 - Visual distress signals required.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Visual distress signals required... (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.110 Visual distress signals... signals selected from the list in § 175.130 or the alternatives in § 175.135, in the number required, are...

Spacelab

NASA Image and Video Library

1992-01-01

Astronaut Ulf Merbold on the stationary seat of the mini-sled, stares into an umbrella-shaped rotating dome with colored dots. Astronaut Merbold, assisted by astronaut David Hilmer, are conducting the Visual Simulator Experiment, a space physiology experiment. The Visual Stimulator Experiment measures the relative importance of visual and vestibular information in determining body orientation. When a person looks at a rotating visual field, a false sensation of self-rotation, called circularvection, results. In weightlessness, circularvection should increase immediately and may continue to increase as the nervous system comes to rely more on visual than vestibular cues. As Astronaut Merbold stares into the rotating dome with a pattern of colored dots and its interior, he turns a knob to indicate his perception of body rotation. The strength of circularvection is calculated by comparing signals from the dome and the knob. The greater the false sense of circularvection, the more the subject is relying on visual information instead of otolith information. The IML-1 mission was the first in a series of Shuttle flights dedicated to fundamental materials and life sciences research with the international partners. The participating space agencies included: NASA, the 14-nation European Space Agency (ESA), the Canadian Space Agency (CSA), the French National Center of Space Studies (CNES), the German Space Agency and the German Aerospace Research Establishment (DAR/DLR), and the National Space Development Agency of Japan (NASDA). Managed by the Marshall Space Flight Center, IML-1 was launched on January 22, 1992 aboard the Space Shuttle Orbiter Discovery (STS-42 mission).

From Agents to Continuous Change via Aesthetics: Learning Mechanics with Visual Agent-Based Computational Modeling

ERIC Educational Resources Information Center

Sengupta, Pratim; Farris, Amy Voss; Wright, Mason

2012-01-01

Novice learners find motion as a continuous process of change challenging to understand. In this paper, we present a pedagogical approach based on agent-based, visual programming to address this issue. Integrating agent-based programming, in particular, Logo programming, with curricular science has been shown to be challenging in previous research…

Long-Term Visual Training Increases Visual Acuity and Long-Term Monocular Deprivation Promotes Ocular Dominance Plasticity in Adult Standard Cage-Raised Mice.

PubMed

Hosang, Leon; Yusifov, Rashad; Löwel, Siegrid

2018-01-01

For routine behavioral tasks, mice predominantly rely on olfactory cues and tactile information. In contrast, their visual capabilities appear rather restricted, raising the question whether they can improve if vision gets more behaviorally relevant. We therefore performed long-term training using the visual water task (VWT): adult standard cage (SC)-raised mice were trained to swim toward a rewarded grating stimulus so that using visual information avoided excessive swimming toward nonrewarded stimuli. Indeed, and in contrast to old mice raised in a generally enriched environment (Greifzu et al., 2016), long-term VWT training increased visual acuity (VA) on average by more than 30% to 0.82 cycles per degree (cyc/deg). In an individual animal, VA even increased to 1.49 cyc/deg, i.e., beyond the rat range of VAs. Since visual experience enhances the spatial frequency threshold of the optomotor (OPT) reflex of the open eye after monocular deprivation (MD), we also quantified monocular vision after VWT training. Monocular VA did not increase reliably, and eye reopening did not initiate a decline to pre-MD values as observed by optomotry; VA values rather increased by continued VWT training. Thus, optomotry and VWT measure different parameters of mouse spatial vision. Finally, we tested whether long-term MD induced ocular dominance (OD) plasticity in the visual cortex of adult [postnatal day (P)162-P182] SC-raised mice. This was indeed the case: 40-50 days of MD induced OD shifts toward the open eye in both VWT-trained and, surprisingly, also in age-matched mice without VWT training. These data indicate that (1) long-term VWT training increases adult mouse VA, and (2) long-term MD induces OD shifts also in adult SC-raised mice.

Lower pitch is larger, yet falling pitches shrink.

PubMed

Eitan, Zohar; Schupak, Asi; Gotler, Alex; Marks, Lawrence E

2014-01-01

Experiments using diverse paradigms, including speeded discrimination, indicate that pitch and visually-perceived size interact perceptually, and that higher pitch is congruent with smaller size. While nearly all of these studies used static stimuli, here we examine the interaction of dynamic pitch and dynamic size, using Garner's speeded discrimination paradigm. Experiment 1 examined the interaction of continuous rise/fall in pitch and increase/decrease in object size. Experiment 2 examined the interaction of static pitch and size (steady high/low pitches and large/small visual objects), using an identical procedure. Results indicate that static and dynamic auditory and visual stimuli interact in opposite ways. While for static stimuli (Experiment 2), higher pitch is congruent with smaller size (as suggested by earlier work), for dynamic stimuli (Experiment 1), ascending pitch is congruent with growing size, and descending pitch with shrinking size. In addition, while static stimuli (Experiment 2) exhibit both congruence and Garner effects, dynamic stimuli (Experiment 1) present congruence effects without Garner interference, a pattern that is not consistent with prevalent interpretations of Garner's paradigm. Our interpretation of these results focuses on effects of within-trial changes on processing in dynamic tasks and on the association of changes in apparent size with implied changes in distance. Results suggest that static and dynamic stimuli can differ substantially in their cross-modal mappings, and may rely on different processing mechanisms.

Post-explant visualization of thrombi in outflow grafts and their junction to a continuous-flow total artificial heart using a high-definition miniaturized camera.

PubMed

Karimov, Jamshid H; Horvath, David; Sunagawa, Gengo; Byram, Nicole; Moazami, Nader; Golding, Leonard A R; Fukamachi, Kiyotaka

2015-12-01

Post-explant evaluation of the continuous-flow total artificial heart in preclinical studies can be extremely challenging because of the device's unique architecture. Determining the exact location of tissue regeneration, neointima formation, and thrombus is particularly important. In this report, we describe our first successful experience with visualizing the Cleveland Clinic continuous-flow total artificial heart using a custom-made high-definition miniature camera.

Visual artificial grammar learning: comparative research on humans, kea (Nestor notabilis) and pigeons (Columba livia)

PubMed Central

Stobbe, Nina; Westphal-Fitch, Gesche; Aust, Ulrike; Fitch, W. Tecumseh

2012-01-01

Artificial grammar learning (AGL) provides a useful tool for exploring rule learning strategies linked to general purpose pattern perception. To be able to directly compare performance of humans with other species with different memory capacities, we developed an AGL task in the visual domain. Presenting entire visual patterns simultaneously instead of sequentially minimizes the amount of required working memory. This approach allowed us to evaluate performance levels of two bird species, kea (Nestor notabilis) and pigeons (Columba livia), in direct comparison to human participants. After being trained to discriminate between two types of visual patterns generated by rules at different levels of computational complexity and presented on a computer screen, birds and humans received further training with a series of novel stimuli that followed the same rules, but differed in various visual features from the training stimuli. Most avian and all human subjects continued to perform well above chance during this initial generalization phase, suggesting that they were able to generalize learned rules to novel stimuli. However, detailed testing with stimuli that violated the intended rules regarding the exact number of stimulus elements indicates that neither bird species was able to successfully acquire the intended pattern rule. Our data suggest that, in contrast to humans, these birds were unable to master a simple rule above the finite-state level, even with simultaneous item presentation and despite intensive training. PMID:22688635

Both hand position and movement direction modulate visual attention

PubMed Central

Festman, Yariv; Adam, Jos J.; Pratt, Jay; Fischer, Martin H.

2013-01-01

The current study explored effects of continuous hand motion on the allocation of visual attention. A concurrent paradigm was used to combine visually concealed continuous hand movements with an attentionally demanding letter discrimination task. The letter probe appeared contingent upon the moving right hand passing through one of six positions. Discrimination responses were then collected via a keyboard press with the static left hand. Both the right hand's position and its movement direction systematically contributed to participants' visual sensitivity. Discrimination performance increased substantially when the right hand was distant from, but moving toward the visual probe location (replicating the far-hand effect, Festman et al., 2013). However, this effect disappeared when the probe appeared close to the static left hand, supporting the view that static and dynamic features of both hands combine in modulating pragmatic maps of attention. PMID:24098288

Quantifying temporal glucose variability in diabetes via continuous glucose monitoring: mathematical methods and clinical application.

PubMed

Kovatchev, Boris P; Clarke, William L; Breton, Marc; Brayman, Kenneth; McCall, Anthony

2005-12-01

Continuous glucose monitors (CGMs) collect detailed blood glucose (BG) time series, which carry significant information about the dynamics of BG fluctuations. In contrast, the methods for analysis of CGM data remain those developed for infrequent BG self-monitoring. As a result, important information about the temporal structure of the data is lost during the translation of raw sensor readings into clinically interpretable statistics and images. The following mathematical methods are introduced into the field of CGM data interpretation: (1) analysis of BG rate of change; (2) risk analysis using previously reported Low/High BG Indices and Poincare (lag) plot of risk associated with temporal BG variability; and (3) spatial aggregation of the process of BG fluctuations and its Markov chain visualization. The clinical application of these methods is illustrated by analysis of data of a patient with Type 1 diabetes mellitus who underwent islet transplantation and with data from clinical trials. Normative data [12,025 reference (YSI device, Yellow Springs Instruments, Yellow Springs, OH) BG determinations] in patients with Type 1 diabetes mellitus who underwent insulin and glucose challenges suggest that the 90%, 95%, and 99% confidence intervals of BG rate of change that could be maximally sustained over 15-30 min are [-2,2], [-3,3], and [-4,4] mg/dL/min, respectively. BG dynamics and risk parameters clearly differentiated the stages of transplantation and the effects of medication. Aspects of treatment were clearly visualized by graphs of BG rate of change and Low/High BG Indices, by a Poincare plot of risk for rapid BG fluctuations, and by a plot of the aggregated Markov process. Advanced analysis and visualization of CGM data allow for evaluation of dynamical characteristics of diabetes and reveal clinical information that is inaccessible via standard statistics, which do not take into account the temporal structure of the data. The use of such methods improves the assessment of patients' glycemic control.

32 CFR 813.1 - Purpose of the visual information documentation (VIDOC) program.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Purpose of the visual information documentation (VIDOC) program. 813.1 Section 813.1 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE SALES AND SERVICES VISUAL INFORMATION DOCUMENTATION PROGRAM § 813.1 Purpose of the visual information documentation (VIDOC) program....

Adding words to the brain's visual dictionary: novel word learning selectively sharpens orthographic representations in the VWFA.

PubMed

Glezer, Laurie S; Kim, Judy; Rule, Josh; Jiang, Xiong; Riesenhuber, Maximilian

2015-03-25

The nature of orthographic representations in the human brain is still subject of much debate. Recent reports have claimed that the visual word form area (VWFA) in left occipitotemporal cortex contains an orthographic lexicon based on neuronal representations highly selective for individual written real words (RWs). This theory predicts that learning novel words should selectively increase neural specificity for these words in the VWFA. We trained subjects to recognize novel pseudowords (PWs) and used fMRI rapid adaptation to compare neural selectivity with RWs, untrained PWs (UTPWs), and trained PWs (TPWs). Before training, PWs elicited broadly tuned responses, whereas responses to RWs indicated tight tuning. After training, TPW responses resembled those of RWs, whereas UTPWs continued to show broad tuning. This change in selectivity was specific to the VWFA. Therefore, word learning appears to selectively increase neuronal specificity for the new words in the VWFA, thereby adding these words to the brain's visual dictionary. Copyright © 2015 the authors 0270-6474/15/354965-08$15.00/0.

Severe visual loss and cerebral infarction after injection of hyaluronic acid gel.

PubMed

Kim, Eung Gyu; Eom, Tae Kyung; Kang, Seok Joo

2014-01-01

We report a case of a 23-year-old man with cerebral infarction and permanent visual loss after injection of a hyaluronic acid gel filler for augmentation rhinoplasty. The patient was admitted to the hospital with complaints of loss of vision in the right eye, facial paralysis on the right side, and paralysis of the left limbs with severe pain during augmentation rhinoplasty with filler injection. Brain magnetic resonance imaging and computed tomography showed ophthalmic artery obstruction and right middle cerebral artery infarction. Acute thrombolysis was performed to treat the infarction; however, the patient's condition did not improve. Intracerebral hemorrhage in the right temporal/frontal/occipital/parietal lobe, subarachnoid hemorrhage, and midline shifting were observed on brain computed tomography after 24 hours after thrombolysis. Emergency decompressive craniectomy was performed. After the surgery, the patient continued to experience drowsiness, with no improvement in visual loss and motor weakness. Three months later, he could walk with cane. This case indicates that surgeons who administer filler injections should be familiar with the possibility of accidental intravascular injection and should explain the adverse effects of fillers to patients before surgery.

Infants are superior in implicit crossmodal learning and use other learning mechanisms than adults

PubMed Central

von Frieling, Marco; Röder, Brigitte

2017-01-01

During development internal models of the sensory world must be acquired which have to be continuously adapted later. We used event-related potentials (ERP) to test the hypothesis that infants extract crossmodal statistics implicitly while adults learn them when task relevant. Participants were passively exposed to frequent standard audio-visual combinations (A1V1, A2V2, p=0.35 each), rare recombinations of these standard stimuli (A1V2, A2V1, p=0.10 each), and a rare audio-visual deviant with infrequent auditory and visual elements (A3V3, p=0.10). While both six-month-old infants and adults differentiated between rare deviants and standards involving early neural processing stages only infants were sensitive to crossmodal statistics as indicated by a late ERP difference between standard and recombined stimuli. A second experiment revealed that adults differentiated recombined and standard combinations when crossmodal combinations were task relevant. These results demonstrate a heightened sensitivity for crossmodal statistics in infants and a change in learning mode from infancy to adulthood. PMID:28949291

Non-conscious processing of motion coherence can boost conscious access.

PubMed

Kaunitz, Lisandro; Fracasso, Alessio; Lingnau, Angelika; Melcher, David

2013-01-01

Research on the scope and limits of non-conscious vision can advance our understanding of the functional and neural underpinnings of visual awareness. Here we investigated whether distributed local features can be bound, outside of awareness, into coherent patterns. We used continuous flash suppression (CFS) to create interocular suppression, and thus lack of awareness, for a moving dot stimulus that varied in terms of coherence with an overall pattern (radial flow). Our results demonstrate that for radial motion, coherence favors the detection of patterns of moving dots even under interocular suppression. Coherence caused dots to break through the masks more often: this indicates that the visual system was able to integrate low-level motion signals into a coherent pattern outside of visual awareness. In contrast, in an experiment using meaningful or scrambled biological motion we did not observe any increase in the sensitivity of detection for meaningful patterns. Overall, our results are in agreement with previous studies on face processing and with the hypothesis that certain features are spatiotemporally bound into coherent patterns even outside of attention or awareness.

A 2D virtual reality system for visual goal-driven navigation in zebrafish larvae

PubMed Central

Jouary, Adrien; Haudrechy, Mathieu; Candelier, Raphaël; Sumbre, German

2016-01-01

Animals continuously rely on sensory feedback to adjust motor commands. In order to study the role of visual feedback in goal-driven navigation, we developed a 2D visual virtual reality system for zebrafish larvae. The visual feedback can be set to be similar to what the animal experiences in natural conditions. Alternatively, modification of the visual feedback can be used to study how the brain adapts to perturbations. For this purpose, we first generated a library of free-swimming behaviors from which we learned the relationship between the trajectory of the larva and the shape of its tail. Then, we used this technique to infer the intended displacements of head-fixed larvae, and updated the visual environment accordingly. Under these conditions, larvae were capable of aligning and swimming in the direction of a whole-field moving stimulus and produced the fine changes in orientation and position required to capture virtual prey. We demonstrate the sensitivity of larvae to visual feedback by updating the visual world in real-time or only at the end of the discrete swimming episodes. This visual feedback perturbation caused impaired performance of prey-capture behavior, suggesting that larvae rely on continuous visual feedback during swimming. PMID:27659496

Upper extremity rehabilitation of stroke: facilitation of corticospinal excitability using virtual mirror paradigm.

PubMed

Kang, Youn Joo; Park, Hae Kyung; Kim, Hyun Jung; Lim, Taeo; Ku, Jeonghun; Cho, Sangwoo; Kim, Sun I; Park, Eun Sook

2012-10-04

Several experimental studies in stroke patients suggest that mirror therapy and various virtual reality programs facilitate motor rehabilitation. However, the underlying mechanisms for these therapeutic effects have not been previously described. We attempted to delineate the changes in corticospinal excitability when individuals were asked to exercise their upper extremity using a real mirror and virtual mirror. Moreover, we attempted to delineate the role of visual modulation within the virtual environment that affected corticospinal excitability in healthy subjects and stroke patients. A total of 18 healthy subjects and 18 hemiplegic patients were enrolled into the study. Motor evoked potential (MEP)s from transcranial magnetic stimulation were recorded in the flexor carpi radialis of the non-dominant or affected upper extremity using three different conditions: (A) relaxation; (B) real mirror; and (C) virtual mirror. Moreover, we compared the MEPs from the virtual mirror paradigm using continuous visual feedback or intermittent visual feedback. The rates of amplitude increment and latency decrement of MEPs in both groups were higher during the virtual mirror task than during the real mirror. In healthy subjects and stroke patients, the virtual mirror task with intermittent visual feedback significantly facilitated corticospinal excitability of MEPs compared with continuous visual feedback. Corticospinal excitability was facilitated to a greater extent in the virtual mirror paradigm than in the real mirror and in intermittent visual feedback than in the continuous visual feedback, in both groups. This provides neurophysiological evidence supporting the application of the virtual mirror paradigm using various visual modulation technologies to upper extremity rehabilitation in stroke patients.

Upper extremity rehabilitation of stroke: Facilitation of corticospinal excitability using virtual mirror paradigm

PubMed Central

2012-01-01

Background Several experimental studies in stroke patients suggest that mirror therapy and various virtual reality programs facilitate motor rehabilitation. However, the underlying mechanisms for these therapeutic effects have not been previously described. Objectives We attempted to delineate the changes in corticospinal excitability when individuals were asked to exercise their upper extremity using a real mirror and virtual mirror. Moreover, we attempted to delineate the role of visual modulation within the virtual environment that affected corticospinal excitability in healthy subjects and stroke patients. Methods A total of 18 healthy subjects and 18 hemiplegic patients were enrolled into the study. Motor evoked potential (MEP)s from transcranial magnetic stimulation were recorded in the flexor carpi radialis of the non-dominant or affected upper extremity using three different conditions: (A) relaxation; (B) real mirror; and (C) virtual mirror. Moreover, we compared the MEPs from the virtual mirror paradigm using continuous visual feedback or intermittent visual feedback. Results The rates of amplitude increment and latency decrement of MEPs in both groups were higher during the virtual mirror task than during the real mirror. In healthy subjects and stroke patients, the virtual mirror task with intermittent visual feedback significantly facilitated corticospinal excitability of MEPs compared with continuous visual feedback. Conclusion Corticospinal excitability was facilitated to a greater extent in the virtual mirror paradigm than in the real mirror and in intermittent visual feedback than in the continuous visual feedback, in both groups. This provides neurophysiological evidence supporting the application of the virtual mirror paradigm using various visual modulation technologies to upper extremity rehabilitation in stroke patients. PMID:23035951

Ventral and Dorsal Pathways Relate Differently to Visual Awareness of Body Postures under Continuous Flash Suppression

PubMed Central

Goebel, Rainer

2018-01-01

Abstract Visual perception includes ventral and dorsal stream processes. However, it is still unclear whether the former is predominantly related to conscious and the latter to nonconscious visual perception as argued in the literature. In this study upright and inverted body postures were rendered either visible or invisible under continuous flash suppression (CFS), while brain activity of human participants was measured with functional MRI (fMRI). Activity in the ventral body-sensitive areas was higher during visible conditions. In comparison, activity in the posterior part of the bilateral intraparietal sulcus (IPS) showed a significant interaction of stimulus orientation and visibility. Our results provide evidence that dorsal stream areas are less associated with visual awareness. PMID:29445766

Fluid leak indicator

NASA Technical Reports Server (NTRS)

Anderson, G. E.; Loo, S. (Inventor)

1985-01-01

A fluid leak indicator for detecting and indicating leaks in visually inaccessible fluid tubing joints, such as those obstructed by insulation includes a bag system and a wicking system surrounding or wrapping the joints under the visual obstructing material. Leaking fluid is collected in the bag or on the wicking material where it is conducted along the wicking material to a visily accessible capturing transparent indicator bulb for providing a visual indication of the leak without requiring a chemical change in the capturing indicator bulb.

47 CFR 80.293 - Check bearings by authorized ship personnel.

Code of Federal Regulations, 2010 CFR

2010-10-01

....293 Section 80.293 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL... comparison of simultaneous visual and radio direction finder bearings. At least one comparison bearing must... visual bearing relative to the ship's heading and the difference between the visual and radio direction...

Suppressed visual looming stimuli are not integrated with auditory looming signals: Evidence from continuous flash suppression.

PubMed

Moors, Pieter; Huygelier, Hanne; Wagemans, Johan; de-Wit, Lee; van Ee, Raymond

2015-01-01

Previous studies using binocular rivalry have shown that signals in a modality other than the visual can bias dominance durations depending on their congruency with the rivaling stimuli. More recently, studies using continuous flash suppression (CFS) have reported that multisensory integration influences how long visual stimuli remain suppressed. In this study, using CFS, we examined whether the contrast thresholds for detecting visual looming stimuli are influenced by a congruent auditory stimulus. In Experiment 1, we show that a looming visual stimulus can result in lower detection thresholds compared to a static concentric grating, but that auditory tone pips congruent with the looming stimulus did not lower suppression thresholds any further. In Experiments 2, 3, and 4, we again observed no advantage for congruent multisensory stimuli. These results add to our understanding of the conditions under which multisensory integration is possible, and suggest that certain forms of multisensory integration are not evident when the visual stimulus is suppressed from awareness using CFS.

Dissociations of the number and precision of visual short-term memory representations in change detection.

PubMed

Xie, Weizhen; Zhang, Weiwei

2017-11-01

The present study dissociated the number (i.e., quantity) and precision (i.e., quality) of visual short-term memory (STM) representations in change detection using receiver operating characteristic (ROC) and experimental manipulations. Across three experiments, participants performed both recognition and recall tests of visual STM using the change-detection task and the continuous color-wheel recall task, respectively. Experiment 1 demonstrated that the estimates of the number and precision of visual STM representations based on the ROC model of change-detection performance were robustly correlated with the corresponding estimates based on the mixture model of continuous-recall performance. Experiments 2 and 3 showed that the experimental manipulation of mnemonic precision using white-noise masking and the experimental manipulation of the number of encoded STM representations using consolidation masking produced selective effects on the corresponding measures of mnemonic precision and the number of encoded STM representations, respectively, in both change-detection and continuous-recall tasks. Altogether, using the individual-differences (Experiment 1) and experimental dissociation (Experiment 2 and 3) approaches, the present study demonstrated the some-or-none nature of visual STM representations across recall and recognition.

VFMA: Topographic Analysis of Sensitivity Data From Full-Field Static Perimetry

PubMed Central

Weleber, Richard G.; Smith, Travis B.; Peters, Dawn; Chegarnov, Elvira N.; Gillespie, Scott P.; Francis, Peter J.; Gardiner, Stuart K.; Paetzold, Jens; Dietzsch, Janko; Schiefer, Ulrich; Johnson, Chris A.

2015-01-01

Purpose: To analyze static visual field sensitivity with topographic models of the hill of vision (HOV), and to characterize several visual function indices derived from the HOV volume. Methods: A software application, Visual Field Modeling and Analysis (VFMA), was developed for static perimetry data visualization and analysis. Three-dimensional HOV models were generated for 16 healthy subjects and 82 retinitis pigmentosa patients. Volumetric visual function indices, which are measures of quantity and comparable regardless of perimeter test pattern, were investigated. Cross-validation, reliability, and cross-sectional analyses were performed to assess this methodology and compare the volumetric indices to conventional mean sensitivity and mean deviation. Floor effects were evaluated by computer simulation. Results: Cross-validation yielded an overall R2 of 0.68 and index of agreement of 0.89, which were consistent among subject groups, indicating good accuracy. Volumetric and conventional indices were comparable in terms of test–retest variability and discriminability among subject groups. Simulated floor effects did not negatively impact the repeatability of any index, but large floor changes altered the discriminability for regional volumetric indices. Conclusions: VFMA is an effective tool for clinical and research analyses of static perimetry data. Topographic models of the HOV aid the visualization of field defects, and topographically derived indices quantify the magnitude and extent of visual field sensitivity. Translational Relevance: VFMA assists with the interpretation of visual field data from any perimetric device and any test location pattern. Topographic models and volumetric indices are suitable for diagnosis, monitoring of field loss, patient counseling, and endpoints in therapeutic trials. PMID:25938002

Selective weighting of action-related feature dimensions in visual working memory.

PubMed

Heuer, Anna; Schubö, Anna

2017-08-01

Planning an action primes feature dimensions that are relevant for that particular action, increasing the impact of these dimensions on perceptual processing. Here, we investigated whether action planning also affects the short-term maintenance of visual information. In a combined memory and movement task, participants were to memorize items defined by size or color while preparing either a grasping or a pointing movement. Whereas size is a relevant feature dimension for grasping, color can be used to localize the goal object and guide a pointing movement. The results showed that memory for items defined by size was better during the preparation of a grasping movement than during the preparation of a pointing movement. Conversely, memory for color tended to be better when a pointing movement rather than a grasping movement was being planned. This pattern was not only observed when the memory task was embedded within the preparation period of the movement, but also when the movement to be performed was only indicated during the retention interval of the memory task. These findings reveal that a weighting of information in visual working memory according to action relevance can even be implemented at the representational level during maintenance, demonstrating that our actions continue to influence visual processing beyond the perceptual stage.

The influence of gender and hormone status on the severity and progression of keratoconus.

PubMed

Fink, Barbara A; Sinnott, Loraine T; Wagner, Heidi; Friedman, Chad; Zadnik, Karla

2010-01-01

To assess the effects of gender and hormone status on the severity and progression of keratoconus in patients enrolled in the Collaborative Longitudinal Evaluation of Keratoconus Study. The severity and progression of keratoconus in both men (M) and women were evaluated over a 4-year period that encompassed menopausal transition for hormone-active women (HA) and hormone-inactive women (HI). Four outcome measures were selected as indicators of the severity of keratoconus: high-contrast best-corrected visual acuity, low-contrast best-corrected visual acuity, the steep keratometric measurement, and corneal scarring (yes/no). There were no statistically significant differences among the 3 groups (M, HA, and HI) in race, history of atopic disease, family history of keratoconus, or rigid contact lens wear in the right and left eyes. At baseline, there were no significant differences among the 3 groups in high-contrast best-corrected visual acuity, low-contrast best-corrected visual acuity, or steep keratometric reading. Progression of keratoconus, as assessed by changes in these 3 continuous variables, was equal for the 3 groups. M had more corneal scarring than did HA or HI; however, there was no progression of scarring for any of the groups. Keratoconus progressed in both men and women, aged 48-59 years; however, there were no differences among the groups in progression.

Audiovisual speech perception in infancy: The influence of vowel identity and infants' productive abilities on sensitivity to (mis)matches between auditory and visual speech cues.

PubMed

Altvater-Mackensen, Nicole; Mani, Nivedita; Grossmann, Tobias

2016-02-01

Recent studies suggest that infants' audiovisual speech perception is influenced by articulatory experience (Mugitani et al., 2008; Yeung & Werker, 2013). The current study extends these findings by testing if infants' emerging ability to produce native sounds in babbling impacts their audiovisual speech perception. We tested 44 6-month-olds on their ability to detect mismatches between concurrently presented auditory and visual vowels and related their performance to their productive abilities and later vocabulary size. Results show that infants' ability to detect mismatches between auditory and visually presented vowels differs depending on the vowels involved. Furthermore, infants' sensitivity to mismatches is modulated by their current articulatory knowledge and correlates with their vocabulary size at 12 months of age. This suggests that-aside from infants' ability to match nonnative audiovisual cues (Pons et al., 2009)-their ability to match native auditory and visual cues continues to develop during the first year of life. Our findings point to a potential role of salient vowel cues and productive abilities in the development of audiovisual speech perception, and further indicate a relation between infants' early sensitivity to audiovisual speech cues and their later language development. PsycINFO Database Record (c) 2016 APA, all rights reserved.

Visual Indicators on Vaccine Boxes as Early Warning Tools to Identify Potential Freeze Damage.

PubMed

Angoff, Ronald; Wood, Jillian; Chernock, Maria C; Tipping, Diane

2015-07-01

The aim of this study was to determine whether the use of visual freeze indicators on vaccines would assist health care providers in identifying vaccines that may have been exposed to potentially damaging temperatures. Twenty-seven sites in Connecticut involved in the Vaccine for Children Program participated. In addition to standard procedures, visual freeze indicators (FREEZEmarker ® L; Temptime Corporation, Morris Plains, NJ) were affixed to each box of vaccine that required refrigeration but must not be frozen. Temperatures were monitored twice daily. During the 24 weeks, all 27 sites experienced triggered visual freeze indicator events in 40 of the 45 refrigerators. A total of 66 triggered freeze indicator events occurred in all 4 types of refrigerators used. Only 1 of the freeze events was identified by a temperature-monitoring device. Temperatures recorded on vaccine data logs before freeze indicator events were within the 35°F to 46°F (2°C to 8°C) range in all but 1 instance. A total of 46,954 doses of freeze-sensitive vaccine were stored at the time of a visual freeze indicator event. Triggered visual freeze indicators were found on boxes containing 6566 doses (14.0% of total doses). Of all doses stored, 14,323 doses (30.5%) were of highly freeze-sensitive vaccine; 1789 of these doses (12.5%) had triggered indicators on the boxes. Visual freeze indicators are useful in the early identification of freeze events involving vaccines. Consideration should be given to including these devices as a component of the temperature-monitoring system for vaccines.

Route Network Construction with Location-Direction-Enabled Photographs

NASA Astrophysics Data System (ADS)

Fujita, Hideyuki; Sagara, Shota; Ohmori, Tadashi; Shintani, Takahiko

2018-05-01

We propose a method for constructing a geometric graph for generating routes that summarize a geographical area and also have visual continuity by using a set of location-direction-enabled photographs. A location- direction-enabled photograph is a photograph that has information about the location (position of the camera at the time of shooting) and the direction (direction of the camera at the time of shooting). Each nodes of the graph corresponds to a location-direction-enabled photograph. The location of each node is the location of the corresponding photograph, and a route on the graph corresponds to a route in the geographic area and a sequence of photographs. The proposed graph is constructed to represent characteristic spots and paths linking the spots, and it is assumed to be a kind of a spatial summarization of the area with the photographs. Therefore, we call the routes on the graph as spatial summary route. Each route on the proposed graph also has a visual continuity, which means that we can understand the spatial relationship among the continuous photographs on the route such as moving forward, backward, turning right, etc. In this study, when the changes in the shooting position and shooting direction satisfied a given threshold, the route was defined to have visual continuity. By presenting the photographs in order along the generated route, information can be presented sequentially, while maintaining visual continuity to a great extent.

The 737 graphite composite flight spoiler flight service evaluation

NASA Technical Reports Server (NTRS)

Coggeshall, R. L.

1982-01-01

A flight service report was prepared which covers the flight service experience of 111 graphite epoxy spoilers on 737 transport aircraft and related ground based environmental exposure of graphite epoxy material specimens. Spoilers were installed on 28 aircraft representing seven major airlines operating throughout the world. Tests of removed spoilers after the seventh year of service continue to indicate modest changes in composite strength properties. Two spoilers were tested, one with 6 and one with 7 years of service, and both had residual strengths that fall within the original static strength scatter band. Both these units had typical service included discrepancies when tested. Based on visual, ultrasonic, and destructive inspection there continues to be no evidence of moisture migration into the honeycomb core and no core corrosion in the deployed units.

21 CFR 886.1150 - Visual acuity chart.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Visual acuity chart. 886.1150 Section 886.1150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1150 Visual acuity chart. (a) Identification...

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…

Smartphone serious games for vision and hearing assessment.

PubMed

Dias, Pedro; Aguiar, Bruno; Sousa, Filipe; Sousa, Augusto

2015-01-01

Falls are the second leading cause of accidental injury deaths worldwide. In this paper, it is intended to define methodologies that permit the evaluation of two potential factors which might have an impact on fall risk, these are: visual and hearing loss. The aim of the work developed is not to replace clinic visits, but to offer the user the means to continue the tracking of his vision and hearing at home, during the long time intervals between clinical tests. Tests conducted in a sample of our target users indicate a good ability to measure vision and hearing using an android smartphone and the proposed methodologies. While some tests require further validation, promising results were achieved in the most common tests for vision and hearing, presenting a good correlation between the system's results when compared to the traditional tests (for distance visual acuity) and the data gathered from the users (for hearing tests).

Clinical Verification of Image Warping as a Potential Aid for the Visually Handicapped

NASA Technical Reports Server (NTRS)

Loshin, David

1996-01-01

The bulk of this research was to designed determine potential of the Programmable Remapper (PR) as a device to enhance vision for the visually handicapped. This research indicated that remapping would have potential as a low vision device if the eye position could be monitored with feedback to specify the proper location of the remapped image. This must be accomplished at high rate so that there is no lag of the image behind the eye position. Since at this time, there is no portable eye monitor device (at a reasonable cost) that will operate under the required conditions, it would not be feasible to continue with remapping experiments for patients with central field defects. However, since patients with peripheral field defects do not have the same eye positioning requirements, they may indeed benefit from this technology. Further investigations must be performed to determine plausibility of this application of remapping.

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

Springmeyer, R R; Brugger, E; Cook, R

The Data group provides data analysis and visualization support to its customers. This consists primarily of the development and support of VisIt, a data analysis and visualization tool. Support ranges from answering questions about the tool, providing classes on how to use the tool, and performing data analysis and visualization for customers. The Information Management and Graphics Group supports and develops tools that enhance our ability to access, display, and understand large, complex data sets. Activities include applying visualization software for large scale data exploration; running video production labs on two networks; supporting graphics libraries and tools for end users;more » maintaining PowerWalls and assorted other displays; and developing software for searching and managing scientific data. Researchers in the Center for Applied Scientific Computing (CASC) work on various projects including the development of visualization techniques for large scale data exploration that are funded by the ASC program, among others. The researchers also have LDRD projects and collaborations with other lab researchers, academia, and industry. The IMG group is located in the Terascale Simulation Facility, home to Dawn, Atlas, BGL, and others, which includes both classified and unclassified visualization theaters, a visualization computer floor and deployment workshop, and video production labs. We continued to provide the traditional graphics group consulting and video production support. We maintained five PowerWalls and many other displays. We deployed a 576-node Opteron/IB cluster with 72 TB of memory providing a visualization production server on our classified network. We continue to support a 128-node Opteron/IB cluster providing a visualization production server for our unclassified systems and an older 256-node Opteron/IB cluster for the classified systems, as well as several smaller clusters to drive the PowerWalls. The visualization production systems includes NFS servers to provide dedicated storage for data analysis and visualization. The ASC projects have delivered new versions of visualization and scientific data management tools to end users and continue to refine them. VisIt had 4 releases during the past year, ending with VisIt 2.0. We released version 2.4 of Hopper, a Java application for managing and transferring files. This release included a graphical disk usage view which works on all types of connections and an aggregated copy feature for quickly transferring massive datasets quickly and efficiently to HPSS. We continue to use and develop Blockbuster and Telepath. Both the VisIt and IMG teams were engaged in a variety of movie production efforts during the past year in addition to the development tasks.« less

Who Should Be Served? A Dilemma in the Field of Blindness and Visual Impairment

ERIC Educational Resources Information Center

Pogrund, Rona L.

2017-01-01

As much as the field of visual impairment has advanced over the last half century and as growing populations of children and adults continue to be served by its practitioners, the issue of personnel shortages to meet the diverse needs of students and consumers seems to continue. More vision professionals are being trained than ever, but it seems…

“To see or not to see: that is the question.” The “Protection-Against-Schizophrenia” (PaSZ) model: evidence from congenital blindness and visuo-cognitive aberrations

PubMed Central

Landgraf, Steffen; Osterheider, Michael

2013-01-01

The causes of schizophrenia are still unknown. For the last 100 years, though, both “absent” and “perfect” vision have been associated with a lower risk for schizophrenia. Hence, vision itself and aberrations in visual functioning may be fundamental to the development and etiological explanations of the disorder. In this paper, we present the “Protection-Against-Schizophrenia” (PaSZ) model, which grades the risk for developing schizophrenia as a function of an individual's visual capacity. We review two vision perspectives: (1) “Absent” vision or how congenital blindness contributes to PaSZ and (2) “perfect” vision or how aberrations in visual functioning are associated with psychosis. First, we illustrate that, although congenitally blind and sighted individuals acquire similar world representations, blind individuals compensate for behavioral shortcomings through neurofunctional and multisensory reorganization. These reorganizations may indicate etiological explanations for their PaSZ. Second, we demonstrate that visuo-cognitive impairments are fundamental for the development of schizophrenia. Deteriorated visual information acquisition and processing contribute to higher-order cognitive dysfunctions and subsequently to schizophrenic symptoms. Finally, we provide different specific therapeutic recommendations for individuals who suffer from visual impairments (who never developed “normal” vision) and individuals who suffer from visual deterioration (who previously had “normal” visual skills). Rather than categorizing individuals as “normal” and “mentally disordered,” the PaSZ model uses a continuous scale to represent psychiatrically relevant human behavior. This not only provides a scientific basis for more fine-grained diagnostic assessments, earlier detection, and more appropriate therapeutic assignments, but it also outlines a trajectory for unraveling the causes of abnormal psychotic human self- and world-perception. PMID:23847557

Endogenously generated gamma-band oscillations in early visual cortex: A neurofeedback study.

PubMed

Merkel, Nina; Wibral, Michael; Bland, Gareth; Singer, Wolf

2018-04-26

Human subjects were trained with neurofeedback (NFB) to enhance the power of narrow-band gamma oscillations in circumscribed regions of early visual cortex. To select the region and the oscillation frequency for NFB training, gamma oscillations were induced with locally presented drifting gratings. The source and frequency of these induced oscillations were determined using beamforming methods. During NFB training the power of narrow band gamma oscillations was continuously extracted from this source with online beamforming and converted into the pitch of a tone signal. We found that seven out of ten subjects were able to selectively increase the amplitude of gamma oscillations in the absence of visual stimulation. One subject however failed completely and two subjects succeeded to manipulate the feedback signal by contraction of muscles. In all subjects the attempts to enhance visual gamma oscillations were associated with an increase of beta oscillations over precentral/frontal regions. Only successful subjects exhibited an additional marked increase of theta oscillations over precentral/prefrontal and temporal regions whereas unsuccessful subjects showed an increase of alpha band oscillations over occipital regions. We argue that spatially confined networks in early visual cortex can be entrained to engage in narrow band gamma oscillations not only by visual stimuli but also by top down signals. We interpret the concomitant increase in beta oscillations as indication for an engagement of the fronto-parietal attention network and the increase of theta oscillations as a correlate of imagery. Our finding support the application of NFB in disease conditions associated with impaired gamma synchronization. © 2018 Wiley Periodicals, Inc.

Feasibility and Preliminary Efficacy of Visual Cue Training to Improve Adaptability of Walking after Stroke: Multi-Centre, Single-Blind Randomised Control Pilot Trial.

PubMed

Hollands, Kristen L; Pelton, Trudy A; Wimperis, Andrew; Whitham, Diane; Tan, Wei; Jowett, Sue; Sackley, Catherine M; Wing, Alan M; Tyson, Sarah F; Mathias, Jonathan; Hensman, Marianne; van Vliet, Paulette M

2015-01-01

Given the importance of vision in the control of walking and evidence indicating varied practice of walking improves mobility outcomes, this study sought to examine the feasibility and preliminary efficacy of varied walking practice in response to visual cues, for the rehabilitation of walking following stroke. This 3 arm parallel, multi-centre, assessor blind, randomised control trial was conducted within outpatient neurorehabilitation services. Community dwelling stroke survivors with walking speed <0.8m/s, lower limb paresis and no severe visual impairments. Over-ground visual cue training (O-VCT), Treadmill based visual cue training (T-VCT), and Usual care (UC) delivered by physiotherapists twice weekly for 8 weeks. Participants were randomised using computer generated random permutated balanced blocks of randomly varying size. Recruitment, retention, adherence, adverse events and mobility and balance were measured before randomisation, post-intervention and at four weeks follow-up. Fifty-six participants participated (18 T-VCT, 19 O-VCT, 19 UC). Thirty-four completed treatment and follow-up assessments. Of the participants that completed, adherence was good with 16 treatments provided over (median of) 8.4, 7.5 and 9 weeks for T-VCT, O-VCT and UC respectively. No adverse events were reported. Post-treatment improvements in walking speed, symmetry, balance and functional mobility were seen in all treatment arms. Outpatient based treadmill and over-ground walking adaptability practice using visual cues are feasible and may improve mobility and balance. Future studies should continue a carefully phased approach using identified methods to improve retention. Clinicaltrials.gov NCT01600391.

21 CFR 886.1360 - Visual field laser instrument.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Visual field laser instrument. 886.1360 Section 886.1360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1360 Visual field laser instrument...

Collinearity Impairs Local Element Visual Search

ERIC Educational Resources Information Center

Jingling, Li; Tseng, Chia-Huei

2013-01-01

In visual searches, stimuli following the law of good continuity attract attention to the global structure and receive attentional priority. Also, targets that have unique features are of high feature contrast and capture attention in visual search. We report on a salient global structure combined with a high orientation contrast to the…

Visual Literacy and the Content Classroom: A Question of Now, Not when

ERIC Educational Resources Information Center

Flynt, E. Sutton; Brozo, William

2010-01-01

Since students are continually influenced by the visual culture surrounding them, content teachers should take steps to capitalize on the potential of instructional and communication technologies (ICT) to enhance their effectiveness. The article discusses the importance of integrating visual literacy and identifies the teaching environment needed…

Capturing Visual Metaphors and Tales: Innovative or Elusive?

ERIC Educational Resources Information Center

Elliot, Dely Lazarte; Reid, Kate; Baumfield, Vivienne

2017-01-01

Despite the exponential growth of visual research in the social sciences in the last three decades, continuing empirical enquiries are arguably more relevant than ever. Earlier research employed visual methods primarily to investigate distinct cultural practices, often seeking the views of marginalized, challenging or hard-to-reach participants.…

32 CFR 811.2 - Release of visual information materials.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 811.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE SALES AND SERVICES RELEASE, DISSEMINATION, AND SALE OF VISUAL INFORMATION MATERIALS § 811.2 Release of visual... Security and Policy Review Program. (b) The Secretary of the Air Force for Legislative Liaison (SAF/LL...

78 FR 12825 - Petition for Extension of Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-25

... the frequency of the required visual track inspections. FRA issued the initial waiver that granted.... SEPTA requests an extension of approval to reduce the frequency of required, visual track inspections... with continuous welded rail. SEPTA proposes to conduct one visual track inspection per week, instead of...

47 CFR 73.653 - Operation of TV aural and visual transmitters.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Operation of TV aural and visual transmitters. 73.653 Section 73.653 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Television Broadcast Stations § 73.653 Operation of TV aural and visual...

Fluid leak indicator

NASA Technical Reports Server (NTRS)

Anderson, George E. (Inventor); Loo, Shu (Inventor)

1989-01-01

A fluid leak indicator (30) for detecting and indicating leaks in visually inaccessible fluid tubing joints (20, 21), such as those obstructed by insulation (24), includes a bag system (25) and a wicking system (30) surrounding or wrapping the joints (20, 21) under the visual obstructing material (24). Leaking fluid is collected in the bag (25) or on the wicking material (34) where it is conducted along the wicking material (34) to a visibly accessible capturing transparent indicator bulb (35) for providing a visual indication of the leak without requiring a chemical change in the capturing indicator bulb (35).

Introduction to the special issue on visual working memory.

PubMed

Wolfe, Jeremy M

2014-10-01

Visual working memory is a volatile, limited-capacity memory that appears to play an important role in our impression of a visual world that is continuous in time. It also mediates between the contents of the mind and the contents of that visual world. Research on visual working memory has become increasingly prominent in recent years. The articles in this special issue of Attention, Perception, & Psychophysics describe new empirical findings and theoretical understandings of the topic.

A dual-trace model for visual sensory memory.

PubMed

Cappiello, Marcus; Zhang, Weiwei

2016-11-01

Visual sensory memory refers to a transient memory lingering briefly after the stimulus offset. Although previous literature suggests that visual sensory memory is supported by a fine-grained trace for continuous representation and a coarse-grained trace of categorical information, simultaneous separation and assessment of these traces can be difficult without a quantitative model. The present study used a continuous estimation procedure to test a novel mathematical model of the dual-trace hypothesis of visual sensory memory according to which visual sensory memory could be modeled as a mixture of 2 von Mises (2VM) distributions differing in standard deviation. When visual sensory memory and working memory (WM) for colors were distinguished using different experimental manipulations in the first 3 experiments, the 2VM model outperformed Zhang and Luck (2008) standard mixture model (SM) representing a mixture of a single memory trace and random guesses, even though SM outperformed 2VM for WM. Experiment 4 generalized 2VM's advantages of fitting visual sensory memory data over SM from color to orientation. Furthermore, a single trace model and 4 other alternative models were ruled out, suggesting the necessity and sufficiency of dual traces for visual sensory memory. Together these results support the dual-trace model of visual sensory memory and provide a preliminary inquiry into the nature of information loss from visual sensory memory to WM. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

A visual-environment simulator with variable contrast

NASA Astrophysics Data System (ADS)

Gusarova, N. F.; Demin, A. V.; Polshchikov, G. V.

1987-01-01

A visual-environment simulator is proposed in which the image contrast can be varied continuously up to the reversal of the image. Contrast variability can be achieved by using two independently adjustable light sources to simultaneously illuminate the carrier of visual information (e.g., a slide or a cinematographic film). It is shown that such a scheme makes it possible to adequately model a complex visual environment.

Modeling Efficient Serial Visual Search

DTIC Science & Technology

2012-08-01

parafovea size) to explore the parameter space associated with serial search efficiency. Visual search as a paradigm has been studied meticulously for...continues (Over, Hooge , Vlaskamp, & Erkelens, 2007). Over et al. (2007) found that participants initially attended to general properties of the search environ...the efficiency of human serial visual search. There were three parameters that were manipulated in the modeling of the visual search process in this

Sea-floor geology of a part of Mamala Bay, Hawaii

USGS Publications Warehouse

Hampton, Monty A.; Torresan, Michael E.; Barber, John H.

1997-01-01

We surveyed the sea-floor geology within a 200-km2 area of Mamala Bay, off Honolulu, Hawaii by collecting and analyzing sidescan sonar images, 3.5-kHz profiles, video and still visual images, and box-core samples. The study area extends from 20-m water depth on the insular shelf to 600-m water depth in a southeast-trending trough. The sidescan images depict three principal types of sea-floor material: low-backscatter natural sediment, high-backscatter drowned carbonate reef, and intermediate-backscatter dredged-material deposits. Cores indicate that the natural sediment is muddy sand, composed of carbonate reef and microfauna debris with some volcanic grains. Vague areal trends in composition are evident. The dredged material comprises poorly sorted, cobble- to clay-size mixtures of reef, volcanic, and man-made debris, up to 35 cm thick. Dredged-material deposits are not evident in the 3.5-kHz profiles. In the sidescan images they appear as isolated, circular to subcircular imprints, apparently formed by individual drops, around the periphery of their occurrence, but they overlap and coalesce to a nearly continuous, intermediate-backscatter blanket toward the center of three disposal sites investigated. We did not observe significant currents during our camera surveys, but there is abundant evidence of sediment reworking: symmetrical and asymmetrical ripples in the visual images, sand waves in the 3.5-kHz profiles and side-scan images, moats around the reefs in 3.5-kHz profiles, winnowed dredged material in the visual images, and burial of dredged material by natural sediment in cores. Most current indicators imply a westerly to northwesterly transport direction, along contours or up-slope, although there are a few areas of easterly indicators. Internal waves probably drive the transport; their possible existence is implied by measured water-column density gradients.

Sea-floor geology of a part of Mamala Bay, Hawai'i

USGS Publications Warehouse

Hampton, M.A.; Torresan, M.E.; Barber, J.H.

1997-01-01

We surveyed the sea-floor geology within a 200-km2 area of Mamala Bay, off Honolulu, Hawai'i, by collecting and analyzing sidescan sonar images, 3.5kHz profiles, video and still visual images, and box-core samples. The study area extends from 20-m water depth on the insular shelf to 600-m water depth in a southeast-trending trough. The sidescan images depict three principal types of seafloor material: low-backscatter natural sediment, high-backscatter drowned carbonate reef, and intermediate-backscatter dredged-material deposits. Cores indicate that the natural sediment is muddy sand, composed of carbonate reef and microfauna debris with some volcanic grains. Vague areal trends in composition are evident. The dredged material comprises poorly sorted, cobble- to clay-size mixtures of reef, volcanic, and man-made debris, up to 35 cm thick. Dredged-material deposits are not evident in the 3.5-kHz profiles. In the sidescan images they appear as isolated, circular to subcircular imprints, apparently formed by individual drops, around the periphery of their occurrence, but they overlap and coalesce to a nearly continuous, intermediate-backscatter blanket toward the center of three disposal sites investigated. We did not observe noticeable currents during our camera surveys, but there is abundant evidence of sediment reworking: symmetrical and asymmetrical ripples in the visual images, sand waves in the 3.5-kHz profiles and side-scan images, moats around the reefs in 3.5-kHz profiles, winnowed dredged material in the visual images, and burial of dredged material by natural sediment in cores. Most current indicators imply a westerly to northwesterly transport direction, along contours or upslope, although there are a few areas of easterly indicators. Internal waves probably drive the transport; their possible existence is implied by measured water-column density gradients.

Storyline Visualizations of Eye Tracking of Movie Viewing

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

Balint, John T.; Arendt, Dustin L.; Blaha, Leslie M.

Storyline visualizations offer an approach that promises to capture the spatio-temporal characteristics of individual observers and simultaneously illustrate emerging group behaviors. We develop a visual analytics approach to parsing, aligning, and clustering fixation sequences from eye tracking data. Visualization of the results captures the similarities and differences across a group of observers performing a common task. We apply our storyline approach to visualize gaze patterns of people watching dynamic movie clips. Storylines mitigate some of the shortcomings of existent spatio-temporal visualization techniques and, importantly, continue to highlight individual observer behavioral dynamics.

Audition and vision share spatial attentional resources, yet attentional load does not disrupt audiovisual integration.

PubMed

Wahn, Basil; König, Peter

2015-01-01

Humans continuously receive and integrate information from several sensory modalities. However, attentional resources limit the amount of information that can be processed. It is not yet clear how attentional resources and multisensory processing are interrelated. Specifically, the following questions arise: (1) Are there distinct spatial attentional resources for each sensory modality? and (2) Does attentional load affect multisensory integration? We investigated these questions using a dual task paradigm: participants performed two spatial tasks (a multiple object tracking task and a localization task), either separately (single task condition) or simultaneously (dual task condition). In the multiple object tracking task, participants visually tracked a small subset of several randomly moving objects. In the localization task, participants received either visual, auditory, or redundant visual and auditory location cues. In the dual task condition, we found a substantial decrease in participants' performance relative to the results of the single task condition. Importantly, participants performed equally well in the dual task condition regardless of the location cues' modality. This result suggests that having spatial information coming from different modalities does not facilitate performance, thereby indicating shared spatial attentional resources for the auditory and visual modality. Furthermore, we found that participants integrated redundant multisensory information similarly even when they experienced additional attentional load in the dual task condition. Overall, findings suggest that (1) visual and auditory spatial attentional resources are shared and that (2) audiovisual integration of spatial information occurs in an pre-attentive processing stage.

Visual and non-visual control of landing movements in humans

PubMed Central

Santello, Marco; McDonagh, Martin J N; Challis, John H

2001-01-01

The role of vision in controlling leg muscle activation in landing from a drop was investigated. Subjects (n = 8) performed 10 drops from four heights (0.2, 0.4, 0.6 and 0.8 m) with and without vision. Drop height was maintained constant throughout each block of trials to allow adaptation. The aim of the study was to assess the extent to which proprioceptive and vestibular information could substitute for the lack of vision in adapting landing movements to different heights. At the final stages of the movement, subjects experienced similar peak centre of body mass (CM) displacements and joint rotations, regardless of the availability of vision. This implies that subjects were able to adapt the control of landing to different heights. The amplitude and timing of electromyographic signals from the leg muscles scaled to drop height in a similar fashion with and without vision. However, variables measured throughout the execution of the movement indicated important differences. Without vision, landings were characterised by 10 % larger ground reaction forces, 10 % smaller knee joint rotations, different time lags between peak joint rotations, and more variable ground reaction forces and times to peak CM displacement. We conclude that non-visual sensory information (a) could not fully compensate for the lack of continuous visual feedback and (b) this non-visual information was used to reorganise the motor output. These results suggest that vision is important for the very accurate timing of muscle activity onset and the kinematics of landing. PMID:11711583

Evaluation of visual and computer-based CT analysis for the identification of functional patterns of obstruction and restriction in hypersensitivity pneumonitis.

PubMed

Jacob, Joseph; Bartholmai, Brian J; Brun, Anne Laure; Egashira, Ryoko; Rajagopalan, Srinivasan; Karwoski, Ronald; Kouranos, Vasileios; Kokosi, Maria; Hansell, David M; Wells, Athol U

2017-11-01

To determine whether computer-based quantification (CALIPER software) is superior to visual computed tomography (CT) scoring in the identification of CT patterns indicative of restrictive and obstructive functional indices in hypersensitivity pneumonitis (HP). A total of 135 consecutive HP patients had CT parenchymal patterns evaluated quantitatively by both visual scoring and CALIPER. Results were evaluated against: forced vital capacity (FVC), total lung capacity (TLC), diffusing capacity for carbon monoxide (DL CO ) and a composite physiological index (CPI) to identify which CT scoring method better correlated with functional indices. CALIPER-derived scores of total interstitial lung disease extent correlated more strongly than visual scores: FVC (CALIPER R = 0.73, visual R = 0.51); DL CO (CALIPER R = 0.61, visual R = 0.48); and CPI (CALIPER R = 0·70, visual R = 0·55). The CT variable that correlated most strongly with restrictive functional indices was CALIPER pulmonary vessel volume (PVV): FVC R = 0.75, DL CO R = 0.68 and CPI R = 0.76. Ground-glass opacity quantified by CALIPER alone demonstrated strong associations with restrictive functional indices: CALIPER FVC R = 0.65; DL CO R = 0.59; CPI R = 0.64; and visual = not significant. Decreased attenuation lung quantified by CALIPER was a better morphological measure of obstructive lung disease than equivalent visual scores as judged by relationships with TLC (CALIPER R = 0.63 and visual R = 0.12). All results were maintained on multivariate analysis. CALIPER improved on visual scoring in HP as judged by restrictive and obstructive functional correlations. Decreased attenuation regions of the lung quantified by CALIPER demonstrated better linkages to obstructive lung physiology than visually quantified CT scores. A novel CALIPER variable, the PVV, demonstrated the strongest linkages with restrictive functional indices and could represent a new automated index of disease severity in HP. © 2017 Asian Pacific Society of Respirology.

Invariant Visual Object and Face Recognition: Neural and Computational Bases, and a Model, VisNet

PubMed Central

Rolls, Edmund T.

2012-01-01

Neurophysiological evidence for invariant representations of objects and faces in the primate inferior temporal visual cortex is described. Then a computational approach to how invariant representations are formed in the brain is described that builds on the neurophysiology. A feature hierarchy model in which invariant representations can be built by self-organizing learning based on the temporal and spatial statistics of the visual input produced by objects as they transform in the world is described. VisNet can use temporal continuity in an associative synaptic learning rule with a short-term memory trace, and/or it can use spatial continuity in continuous spatial transformation learning which does not require a temporal trace. The model of visual processing in the ventral cortical stream can build representations of objects that are invariant with respect to translation, view, size, and also lighting. The model has been extended to provide an account of invariant representations in the dorsal visual system of the global motion produced by objects such as looming, rotation, and object-based movement. The model has been extended to incorporate top-down feedback connections to model the control of attention by biased competition in, for example, spatial and object search tasks. The approach has also been extended to account for how the visual system can select single objects in complex visual scenes, and how multiple objects can be represented in a scene. The approach has also been extended to provide, with an additional layer, for the development of representations of spatial scenes of the type found in the hippocampus. PMID:22723777

Invariant Visual Object and Face Recognition: Neural and Computational Bases, and a Model, VisNet.

PubMed

Rolls, Edmund T

2012-01-01

Neurophysiological evidence for invariant representations of objects and faces in the primate inferior temporal visual cortex is described. Then a computational approach to how invariant representations are formed in the brain is described that builds on the neurophysiology. A feature hierarchy model in which invariant representations can be built by self-organizing learning based on the temporal and spatial statistics of the visual input produced by objects as they transform in the world is described. VisNet can use temporal continuity in an associative synaptic learning rule with a short-term memory trace, and/or it can use spatial continuity in continuous spatial transformation learning which does not require a temporal trace. The model of visual processing in the ventral cortical stream can build representations of objects that are invariant with respect to translation, view, size, and also lighting. The model has been extended to provide an account of invariant representations in the dorsal visual system of the global motion produced by objects such as looming, rotation, and object-based movement. The model has been extended to incorporate top-down feedback connections to model the control of attention by biased competition in, for example, spatial and object search tasks. The approach has also been extended to account for how the visual system can select single objects in complex visual scenes, and how multiple objects can be represented in a scene. The approach has also been extended to provide, with an additional layer, for the development of representations of spatial scenes of the type found in the hippocampus.

Quantifying and visualizing variations in sets of images using continuous linear optimal transport

NASA Astrophysics Data System (ADS)

Kolouri, Soheil; Rohde, Gustavo K.

2014-03-01

Modern advancements in imaging devices have enabled us to explore the subcellular structure of living organisms and extract vast amounts of information. However, interpreting the biological information mined in the captured images is not a trivial task. Utilizing predetermined numerical features is usually the only hope for quantifying this information. Nonetheless, direct visual or biological interpretation of results obtained from these selected features is non-intuitive and difficult. In this paper, we describe an automatic method for modeling visual variations in a set of images, which allows for direct visual interpretation of the most significant differences, without the need for predefined features. The method is based on a linearized version of the continuous optimal transport (OT) metric, which provides a natural linear embedding for the image data set, in which linear combination of images leads to a visually meaningful image. This enables us to apply linear geometric data analysis techniques such as principal component analysis and linear discriminant analysis in the linearly embedded space and visualize the most prominent modes, as well as the most discriminant modes of variations, in the dataset. Using the continuous OT framework, we are able to analyze variations in shape and texture in a set of images utilizing each image at full resolution, that otherwise cannot be done by existing methods. The proposed method is applied to a set of nuclei images segmented from Feulgen stained liver tissues in order to investigate the major visual differences in chromatin distribution of Fetal-Type Hepatoblastoma (FHB) cells compared to the normal cells.

Cross-training in hemispatial neglect: auditory sustained attention training ameliorates visual attention deficits.

PubMed

Van Vleet, Thomas M; DeGutis, Joseph M

2013-03-01

Prominent deficits in spatial attention evident in patients with hemispatial neglect are often accompanied by equally prominent deficits in non-spatial attention (e.g., poor sustained and selective attention, pronounced vigilance decrement). A number of studies now show that deficits in non-spatial attention influence spatial attention. Treatment strategies focused on improving vigilance or sustained attention may effectively remediate neglect. For example, a recent study employing Tonic and Phasic Alertness Training (TAPAT), a task that requires monitoring a constant stream of hundreds of novel scenes, demonstrated group-level (n=12) improvements after training compared to a test-retest control group or active treatment control condition on measures of visual search, midpoint estimation and working memory (DeGutis and Van Vleet, 2010). To determine whether the modality of treatment or stimulus novelty are key factors to improving hemispatial neglect, we designed a similar continuous performance training task in which eight patients with chronic and moderate to severe neglect were challenged to rapidly and continuously discriminate a limited set of centrally presented auditory tones once a day for 9 days (36-min/day). All patients demonstrated significant improvement in several, untrained measures of spatial and non-spatial visual attention, and as a group failed to demonstrate a lateralized attention deficit 24-h post-training compared to a control group of chronic neglect patients who simply waited during the training period. The results indicate that TAPAT-related improvements in hemispatial neglect are likely due to improvements in the intrinsic regulation of supramodal, non-spatial attentional resources. Published by Elsevier Ltd.

The Emergence of Visual Awareness: Temporal Dynamics in Relation to Task and Mask Type

PubMed Central

Kiefer, Markus; Kammer, Thomas

2017-01-01

One aspect of consciousness phenomena, the temporal emergence of visual awareness, has been subject of a controversial debate. How can visual awareness, that is the experiential quality of visual stimuli, be characterized best? Is there a sharp discontinuous or dichotomous transition between unaware and fully aware states, or does awareness emerge gradually encompassing intermediate states? Previous studies yielded conflicting results and supported both dichotomous and gradual views. It is well conceivable that these conflicting results are more than noise, but reflect the dynamic nature of the temporal emergence of visual awareness. Using a psychophysical approach, the present research tested whether the emergence of visual awareness is context-dependent with a temporal two-alternative forced choice task. During backward masking of word targets, it was assessed whether the relative temporal sequence of stimulus thresholds is modulated by the task (stimulus presence, letter case, lexical decision, and semantic category) and by mask type. Four masks with different similarity to the target features were created. Psychophysical functions were then fitted to the accuracy data in the different task conditions as a function of the stimulus mask SOA in order to determine the inflection point (conscious threshold of each feature) and slope of the psychophysical function (transition from unaware to aware within each feature). Depending on feature-mask similarity, thresholds in the different tasks were highly dispersed suggesting a graded transition from unawareness to awareness or had less differentiated thresholds indicating that clusters of features probed by the tasks quite simultaneously contribute to the percept. The latter observation, although not compatible with the notion of a sharp all-or-none transition between unaware and aware states, suggests a less gradual or more discontinuous emergence of awareness. Analyses of slopes of the fitted psychophysical functions also indicated that the emergence of awareness of single features is variable and might be influenced by the continuity of the feature dimensions. The present work thus suggests that the emergence of awareness is neither purely gradual nor dichotomous, but highly dynamic depending on the task and mask type. PMID:28316583

Informing Healthcare Waiting Area Design Using Transparency Attributes: A Comparative Preference Study.

PubMed

Jiang, Shan; Powers, Matthew; Allison, David; Vincent, Ellen

2017-07-01

This study aimed to explore people's visual preference for waiting areas in general hospital environments designed with transparency attributes that fully integrate nature. Waiting can be a tedious and frustrating experience among people seeking healthcare treatments and negatively affect their perception of the quality of care. Positive distractions and supportive designs have gained increasing attraction to improve people's waiting experience. Nature, which has shown therapeutic effects according to a growing amount of evidence, could be a distinguished positive distraction in waiting areas. Additionally, the theory of transparency was operationalized to indicate a spatial continuity between the external nature and the built interiors in general healthcare waiting area design. A survey method was adopted in the study. Twenty-one images of general healthcare waiting areas depicting three design typologies were preselected following a strict procedure, including designs with (a) no window views, (b) limited window views to nature, and (c) transparent spaces with maximum natural views. Ninety-five student participants rated the images based on their visual preference using a Likert-type scale. The results showed that transparent waiting areas were significantly preferred. A significant positive relationship existed between the level of transparency and people's preference scores. The factor analysis indicated additional supportive features that may affect people's preferences, including daylight, perceived warmth, noninstitutional furniture arrangement, visual orientation, and the use of natural materials for interior design. However, these tentative results need to be furthered tested with the real patient population as the next step of this study.

Pilot performance during simulated approaches and landings made with various computer-generated visual glidepath indicators.

DOT National Transportation Integrated Search

1979-01-01

Two simulator experiments were conducted to quantify the effectiveness, in terms of pilot performance, of four different visual glidepath indicator systems in the severely reduced nighttime visual environment often referred to as the 'black hole'. A ...

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.

Conceptual Data Visualization in Archival Finding Aids: Preliminary User Responses

ERIC Educational Resources Information Center

Bahde, Anne

2017-01-01

This paper explores possibilities for marrying data visualization to online archival finding aids, which have continually suffered from usability issues in their long history. This paper describes a project in which two different data visualization models were built to replace sections of an archival finding aid. Users were then shown the models,…

Visualizing second order tensor fields with hyperstreamlines

NASA Technical Reports Server (NTRS)

Delmarcelle, Thierry; Hesselink, Lambertus

1993-01-01

Hyperstreamlines are a generalization to second order tensor fields of the conventional streamlines used in vector field visualization. As opposed to point icons commonly used in visualizing tensor fields, hyperstreamlines form a continuous representation of the complete tensor information along a three-dimensional path. This technique is useful in visulaizing both symmetric and unsymmetric three-dimensional tensor data. Several examples of tensor field visualization in solid materials and fluid flows are provided.

Visual word ambiguity.

PubMed

van Gemert, Jan C; Veenman, Cor J; Smeulders, Arnold W M; Geusebroek, Jan-Mark

2010-07-01

This paper studies automatic image classification by modeling soft assignment in the popular codebook model. The codebook model describes an image as a bag of discrete visual words selected from a vocabulary, where the frequency distributions of visual words in an image allow classification. One inherent component of the codebook model is the assignment of discrete visual words to continuous image features. Despite the clear mismatch of this hard assignment with the nature of continuous features, the approach has been successfully applied for some years. In this paper, we investigate four types of soft assignment of visual words to image features. We demonstrate that explicitly modeling visual word assignment ambiguity improves classification performance compared to the hard assignment of the traditional codebook model. The traditional codebook model is compared against our method for five well-known data sets: 15 natural scenes, Caltech-101, Caltech-256, and Pascal VOC 2007/2008. We demonstrate that large codebook vocabulary sizes completely deteriorate the performance of the traditional model, whereas the proposed model performs consistently. Moreover, we show that our method profits in high-dimensional feature spaces and reaps higher benefits when increasing the number of image categories.

Unconscious response priming during continuous flash suppression

PubMed Central

Grassini, Simone

2018-01-01

Continuous flash suppression (CFS) has become a popular tool for studying unconscious processing, but the level at which unconscious processing of visual stimuli occurs under CFS is not clear. Response priming is a robust and well-understood phenomenon, in which the prime stimulus facilitates overt responses to targets if the prime and target are associated with the same response. We used CFS to study unconscious response priming of shape: arrows with left or right orientation served as primes and targets. The prime was presented near the limen of consciousness and each trial was followed by subjective rating of visibility and a forced-choice response concerning the orientation of the prime in counterbalanced order. In trials without any reported awareness of the presence of the prime, discrimination of the prime’s orientation was at chance level. However, priming was elicited in such unconscious trials. Unconscious priming was not influenced by the prime-target onset-asynchrony (SOA)/prime duration, whereas conscious processing, as indicated by the enhanced discriminability of the prime’s orientation and conscious priming, increased at the longest SOAs/prime durations. These results show that conscious and unconscious processes can be dissociated with CFS and that CFS-masking does not completely suppress unconscious visual processing of shape. PMID:29401503

Continuous-flow automation and hemolysis index: a crucial combination.

PubMed

Lippi, Giuseppe; Plebani, Mario

2013-04-01

A paradigm shift has occurred in the role and organization of laboratory diagnostics over the past decades, wherein consolidation or networking of small laboratories into larger factories and point-of-care testing have simultaneously evolved and now seem to favorably coexist. There is now evidence, however, that the growing implementation of continuous-flow automation, especially in closed systems, has not eased the identification of hemolyzed specimens since the integration of preanalytical and analytical workstations would hide them from visual scrutiny, with an inherent risk that unreliable test results may be released to the stakeholders. Along with other technical breakthroughs, the new generation of laboratory instrumentation is increasingly equipped with systems that can systematically and automatically be tested for a broad series of interferences, the so-called serum indices, which also include the hemolysis index. The routine implementation of these technical tools in clinical laboratories equipped with continuous-flow automation carries several advantages and some drawbacks that are discussed in this article.

Explosion containment device

DOEpatents

Benedick, William B.; Daniel, Charles J.

1977-01-01

The disclosure relates to an explosives storage container for absorbing and containing the blast, fragments and detonation products from a possible detonation of a contained explosive. The container comprises a layer of distended material having sufficient thickness to convert a portion of the kinetic energy of the explosion into thermal energy therein. A continuous wall of steel sufficiently thick to absorb most of the remaining kinetic energy by stretching and expanding, thereby reducing the momentum of detonation products and high velocity fragments, surrounds the layer of distended material. A crushable layer surrounds the continuous steel wall and accommodates the stretching and expanding thereof, transmitting a moderate load to the outer enclosure. These layers reduce the forces of the explosion and the momentum of the products thereof to zero. The outer enclosure comprises a continuous pressure wall enclosing all of the layers. In one embodiment, detonation of the contained explosive causes the outer enclosure to expand which indicates to a visual observer that a detonation has occurred.

DspaceOgreTerrain 3D Terrain Visualization Tool

NASA Technical Reports Server (NTRS)

Myint, Steven; Jain, Abhinandan; Pomerantz, Marc I.

2012-01-01

DspaceOgreTerrain is an extension to the DspaceOgre 3D visualization tool that supports real-time visualization of various terrain types, including digital elevation maps, planets, and meshes. DspaceOgreTerrain supports creating 3D representations of terrains and placing them in a scene graph. The 3D representations allow for a continuous level of detail, GPU-based rendering, and overlaying graphics like wheel tracks and shadows. It supports reading data from the SimScape terrain- modeling library. DspaceOgreTerrain solves the problem of displaying the results of simulations that involve very large terrains. In the past, it has been used to visualize simulations of vehicle traverses on Lunar and Martian terrains. These terrains were made up of billions of vertices and would not have been renderable in real-time without using a continuous level of detail rendering technique.

Unmanned Aircraft System (UAS) Traffic Management (UTM): Enabling Civilian Low-Altitude Airspace and Unmanned Aerial System Operations

NASA Technical Reports Server (NTRS)

Kopardekar, Parimal Hemchandra

2016-01-01

Just a year ago we laid out the UTM challenges and NASA's proposed solutions. During the past year NASA's goal continues to be to conduct research, development and testing to identify airspace operations requirements to enable large-scale visual and beyond visual line-of-sight UAS operations in the low-altitude airspace. Significant progress has been made, and NASA is continuing to move forward.

[Effect of actoprotectors on the work capacity of operators during modeling of various factors of space flight].

PubMed

Bobkov, Iu G; Epishkin, A K

1988-01-01

This paper presents experimental findings indicating that bemithyl, an actoprotective agent, has a beneficial effect on the health status and work capacity of operators during simulated space flight and 56-hour continuous work. The drug enhanced psychophysiological tolerance of the operators and improved the quality of their work: the quality of their compensatory tracking was on the average 10% higher, the number of errors of their porsuit tracking was 1.8 times lower, and the time of visual signal detection was 2.4 times shorter as compared to the placebo controls.

Sulfuric acid on Europa and the radiolytic sulfur cycle.

PubMed

Carlson, R W; Johnson, R E; Anderson, M S

1999-10-01

A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface by magnetospheric plasma bombardment continuously cycles sulfur between three forms: sulfuric acid, sulfur dioxide, and sulfur polymers, with sulfuric acid being about 50 times as abundant as the other forms. Enhanced sulfuric acid concentrations are found in Europa's geologically young terrains, suggesting that low-temperature, liquid sulfuric acid may influence geological processes.

Motor-cognitive dual-task performance: effects of a concurrent motor task on distinct components of visual processing capacity.

PubMed

Künstler, E C S; Finke, K; Günther, A; Klingner, C; Witte, O; Bublak, P

2018-01-01

Dual tasking, or the simultaneous execution of two continuous tasks, is frequently associated with a performance decline that can be explained within a capacity sharing framework. In this study, we assessed the effects of a concurrent motor task on the efficiency of visual information uptake based on the 'theory of visual attention' (TVA). TVA provides parameter estimates reflecting distinct components of visual processing capacity: perceptual threshold, visual processing speed, and visual short-term memory (VSTM) storage capacity. Moreover, goodness-of-fit values and bootstrapping estimates were derived to test whether the TVA-model is validly applicable also under dual task conditions, and whether the robustness of parameter estimates is comparable in single- and dual-task conditions. 24 subjects of middle to higher age performed a continuous tapping task, and a visual processing task (whole report of briefly presented letter arrays) under both single- and dual-task conditions. Results suggest a decline of both visual processing capacity and VSTM storage capacity under dual-task conditions, while the perceptual threshold remained unaffected by a concurrent motor task. In addition, goodness-of-fit values and bootstrapping estimates support the notion that participants processed the visual task in a qualitatively comparable, although quantitatively less efficient way under dual-task conditions. The results support a capacity sharing account of motor-cognitive dual tasking and suggest that even performing a relatively simple motor task relies on central attentional capacity that is necessary for efficient visual information uptake.

Time course of influence on the allocation of attentional resources caused by unconscious fearful faces.

PubMed

Jiang, Yunpeng; Wu, Xia; Saab, Rami; Xiao, Yi; Gao, Xiaorong

2018-05-01

Emotionally affective stimuli have priority in our visual processing even in the absence of conscious processing. However, the influence of unconscious emotional stimuli on our attentional resources remains unclear. Using the continuous flash suppression (CFS) paradigm, we concurrently recorded and analyzed visual event-related potential (ERP) components evoked by the images of suppressed fearful and neutral faces, and the steady-state visual evoked potential (SSVEP) elicited by dynamic Mondrian pictures. Fearful faces, relative to neutral faces, elicited larger late ERP components on parietal electrodes, indicating emotional expression processing without consciousness. More importantly, the presentation of a suppressed fearful face in the CFS resulted in a significantly greater decrease in SSVEP amplitude which started about 1-1.2 s after the face images first appeared. This suggests that the time course of the attentional bias occurs at about 1 s after the appearance of the fearful face and demonstrates that unconscious fearful faces may influence attentional resource allocation. Moreover, we proposed a new method that could eliminate the interaction of ERPs and SSVEPs when recorded concurrently. Copyright © 2018 Elsevier Ltd. All rights reserved.

Differential Visual Processing of Animal Images, with and without Conscious Awareness

PubMed Central

Zhu, Weina; Drewes, Jan; Peatfield, Nicholas A.; Melcher, David

2016-01-01

The human visual system can quickly and efficiently extract categorical information from a complex natural scene. The rapid detection of animals in a scene is one compelling example of this phenomenon, and it suggests the automatic processing of at least some types of categories with little or no attentional requirements (Li et al., 2002, 2005). The aim of this study is to investigate whether the remarkable capability to categorize complex natural scenes exist in the absence of awareness, based on recent reports that “invisible” stimuli, which do not reach conscious awareness, can still be processed by the human visual system (Pasley et al., 2004; Williams et al., 2004; Fang and He, 2005; Jiang et al., 2006, 2007; Kaunitz et al., 2011a). In two experiments, we recorded event-related potentials (ERPs) in response to animal and non-animal/vehicle stimuli in both aware and unaware conditions in a continuous flash suppression (CFS) paradigm. Our results indicate that even in the “unseen” condition, the brain responds differently to animal and non-animal/vehicle images, consistent with rapid activation of animal-selective feature detectors prior to, or outside of, suppression by the CFS mask. PMID:27790106

Differential Visual Processing of Animal Images, with and without Conscious Awareness.

PubMed

Zhu, Weina; Drewes, Jan; Peatfield, Nicholas A; Melcher, David

2016-01-01

The human visual system can quickly and efficiently extract categorical information from a complex natural scene. The rapid detection of animals in a scene is one compelling example of this phenomenon, and it suggests the automatic processing of at least some types of categories with little or no attentional requirements (Li et al., 2002, 2005). The aim of this study is to investigate whether the remarkable capability to categorize complex natural scenes exist in the absence of awareness, based on recent reports that "invisible" stimuli, which do not reach conscious awareness, can still be processed by the human visual system (Pasley et al., 2004; Williams et al., 2004; Fang and He, 2005; Jiang et al., 2006, 2007; Kaunitz et al., 2011a). In two experiments, we recorded event-related potentials (ERPs) in response to animal and non-animal/vehicle stimuli in both aware and unaware conditions in a continuous flash suppression (CFS) paradigm. Our results indicate that even in the "unseen" condition, the brain responds differently to animal and non-animal/vehicle images, consistent with rapid activation of animal-selective feature detectors prior to, or outside of, suppression by the CFS mask.

Looking for an accident: glider pilots' visual management and potentially dangerous final turns.

PubMed

Jarvis, Steve; Harris, Don

2007-06-01

Accidents caused by spinning from low turns continue to kill glider pilots despite the introduction of specific exercises aimed at increasing pilot awareness and recognition of this issue. In-cockpit video cameras were used to analyze flying accuracy and log the areas of visual interest of 36 qualified glider pilots performing final turns in a training glider. Pilots were found to divide their attention between four areas of interest: the view directly ahead; the landing area (right); the airspeed indicator; and an area between the direct ahead view and the landing area. The mean fixation rate was 85 shifts per minute. Significant correlations were found between over-use of rudder and a lack of attention to the view ahead, as well as between the overall fixation rate and poorer coordination in the turn. The results provide some evidence that a relationship exists between pilots' visual management and making turns in a potentially dangerous manner. Pilots who monitor the view ahead for reasonable periods during the final turn while not allowing their scan to become over-busy are those who are most likely to prevent a potential spin.

Evaluating the effectiveness of using electroencephalogram power indices to measure visual fatigue.

PubMed

Hsu, Bin-Wei; Wang, Mao-Jiun J

2013-02-01

Electroencephalography (EEG) is widely used in cognitive and behavioral research. This study evaluates the effectiveness of using the EEG power index to measure visual fatigue. Three common visual fatigue measures, critical-flicker fusion (CFF), near-point accommodation (NPA), and subjective eye-fatigue rating, were used for comparison. The study participants were 20 men with a mean age of 20.4 yr. (SD = 1.5). The experimental task was a car-racing video game. Results indicated that the EEG power indices were valid as a visual fatigue measure and the sensitivity of the objective measures (CFF and EEG power index) was higher than the subjective measure. The EEG beta and EEG alpha were effective for measuring visual fatigue in short- and long-duration tasks, respectively. EEG beta/alpha were the most effective power indexes for the visual fatigue measure.

Long-Term Visual Training Increases Visual Acuity and Long-Term Monocular Deprivation Promotes Ocular Dominance Plasticity in Adult Standard Cage-Raised Mice

PubMed Central

Yusifov, Rashad

2018-01-01

Abstract For routine behavioral tasks, mice predominantly rely on olfactory cues and tactile information. In contrast, their visual capabilities appear rather restricted, raising the question whether they can improve if vision gets more behaviorally relevant. We therefore performed long-term training using the visual water task (VWT): adult standard cage (SC)-raised mice were trained to swim toward a rewarded grating stimulus so that using visual information avoided excessive swimming toward nonrewarded stimuli. Indeed, and in contrast to old mice raised in a generally enriched environment (Greifzu et al., 2016), long-term VWT training increased visual acuity (VA) on average by more than 30% to 0.82 cycles per degree (cyc/deg). In an individual animal, VA even increased to 1.49 cyc/deg, i.e., beyond the rat range of VAs. Since visual experience enhances the spatial frequency threshold of the optomotor (OPT) reflex of the open eye after monocular deprivation (MD), we also quantified monocular vision after VWT training. Monocular VA did not increase reliably, and eye reopening did not initiate a decline to pre-MD values as observed by optomotry; VA values rather increased by continued VWT training. Thus, optomotry and VWT measure different parameters of mouse spatial vision. Finally, we tested whether long-term MD induced ocular dominance (OD) plasticity in the visual cortex of adult [postnatal day (P)162–P182] SC-raised mice. This was indeed the case: 40–50 days of MD induced OD shifts toward the open eye in both VWT-trained and, surprisingly, also in age-matched mice without VWT training. These data indicate that (1) long-term VWT training increases adult mouse VA, and (2) long-term MD induces OD shifts also in adult SC-raised mice. PMID:29379877

Surface flow visualization using indicators

NASA Technical Reports Server (NTRS)

Crowder, J. P.

1982-01-01

Surface flow visualization using indicators in the cryogenic wind tunnel which requires a fresh look at materials and procedures to accommodate the new test conditions is described. Potential liquid and gaseous indicators are identified. The particular materials illustrate the various requirements an indicator must fulfill. The indicator must respond properly to the flow phenomenon of interest and must be observable. Boundary layer transition is the most important phenomenon for which flow visualization indicators may be employed. The visibility of a particular indicator depends on utilizing various optical or chemical reactions. Gaseous indicators are more difficult to utilize, but because of their diversity may present unusual and useful opportunities. Factors to be considered in selecting an indicator include handling safety, toxicity, potential for contamination of the tunnel, and cost.

The Development of Visual and Auditory Selective Attention Using the Central-Incidental Paradigm.

ERIC Educational Resources Information Center

Conroy, Robert L.; Weener, Paul

Analogous auditory and visual central-incidental learning tasks were administered to 24 students from each of the second, fourth, and sixth grades. The visual tasks served as another modification of Hagen's central-incidental learning paradigm, with the interpretation that focal attention processes continue to develop until the age of 12 or 13…

The Forest, the Trees, and the Leaves: Differences of Processing across Development

ERIC Educational Resources Information Center

Krakowski, Claire-Sara; Poirel, Nicolas; Vidal, Julie; Roëll, Margot; Pineau, Arlette; Borst, Grégoire; Houdé, Olivier

2016-01-01

To act and think, children and adults are continually required to ignore irrelevant visual information to focus on task-relevant items. As real-world visual information is organized into structures, we designed a feature visual search task containing 3-level hierarchical stimuli (i.e., local shapes that constituted intermediate shapes that formed…

Thinking Visually: Using Visual Media in the College Classroom

ERIC Educational Resources Information Center

Tobolowsky, Barbara F.

2007-01-01

Getting through to students in the classroom continues to be one of the great mysteries of an educator's life. What will capture their attention, and, more important, what will transform their thinking? Film industry veteran and educator Barbara Tobolowsky returned to her roots in visual media to find answers. Using video clips to introduce a…

A paired case-control comparison of ziprasidone on visual sustained attention and visual selective attention in patients with paranoid schizophrenia.

PubMed

Chen, X; Zhang, Z H; Song, Y; Yuan, W; Liu, Z X; Tang, M Q

2015-08-01

Cognitive impairment is one of the main targets of the treatment to schizophrenia.The atypical antipsychotic was proved to improve the cognition function of the patients. There were a few of clinical trials to detect the effect of medicine treatment on attention function. But the respective changes of sustained and selective attention in the patients with treatment of ziprasidone were rarely investigated. This present study was to explore the effect of ziprasidone on visual sustained and selective attention in schizophrenia. There were 81 patients who were treated with ziprasidone and matched with 81 healthy controls in this open-label trial. The functions were evaluated by Continuous Performance Test (CPT) and Color Word Test (CWT) at baseline and eight weeks later. Between two groups the functions were compared at the two time points, and in patients group those were compared prior to and post treatment. As compared with healthy controls, the functions of the patients were worse. But after 8 weeks treatment of ziprasidone the functions improved in some degree, which were indicated by the change of CPT and CWT indexes. Furthermore, those of patients post treatment were better than prior to treatment. Patients with paranoid schizophrenia have visual sustained and selective attention deficits. The deficits can be improved partly with ziprasidone treatment.

Selective attention in peacocks during predator detection.

PubMed

Yorzinski, Jessica L; Platt, Michael L

2014-05-01

Predation can exert strong selective pressure on the evolution of behavioral and morphological traits in birds. Because predator avoidance is key to survival and birds rely heavily on visual perception, predation may have shaped avian visual systems as well. To address this question, we examined the role of visual attention in antipredator behavior in peacocks (Pavo cristatus). Peacocks were exposed to a model predator while their gaze was continuously recorded with a telemetric eye-tracker. We found that peacocks spent more time looking at and made more fixations on the predator compared to the same spatial location before the predator was revealed. The duration of fixations they directed toward conspecifics and environmental features decreased after the predator was revealed, indicating that the peacocks were rapidly scanning their environment with their eyes. Maximum eye movement amplitudes and amplitudes of consecutive saccades were similar before and after the predator was revealed. In cases where conspecifics detected the predator first, peacocks appeared to learn that danger was present by observing conspecifics' antipredator behavior. Peacocks were faster to detect the predator when they were fixating closer to the area where the predator would eventually appear. In addition, pupil size increased after predator exposure, consistent with increased physiological arousal. These findings demonstrate that peacocks selectively direct their attention toward predatory threats and suggest that predation has influenced the evolution of visual orienting systems.

Ultra-fast ipsilateral DPOAE adaptation not modulated by attention?

NASA Astrophysics Data System (ADS)

Dalhoff, Ernst; Zelle, Dennis; Gummer, Anthony W.

2018-05-01

Efferent stimulation of outer hair cells is supposed to attenuate cochlear amplification of sound waves and is accompanied by reduced DPOAE amplitudes. Recently, a method using two subsequent f2 pulses during presentation of a longer f1 pulse was introduced to measure fast ipsilateral adaptation effects on separated DPOAE components. Compensating primary-tone onsets for their latencies at the f2-tonotopic place, the average adaptation measured in four normal-hearing subjects was 5.0 dB with a time constant below 5 ms. In the present study, two experiments were performed to determine the origin of this ultra-fast ipsilateral adaptation effect. The first experiment measured ultra-fast ipsilateral adaptation using a two-pulse paradigm at three frequencies in the four subjects, while controlling for visual attention of the subjects. The other experiment also controlled for visual attention, but utilized a sequence of f2 short pulses in the presence of a continuous f1 tone to sample ipsilateral adaptation effects with longer time constants in eight subjects. In the first experiment, no significant change in the ultra-fast adaptation between non-directed attention and visual attention could be detected. In contrast, the second experiment revealed significant changes in the magnitude of the slower ipsilateral adaptation in the visual-attention condition. In conclusion, the lack of an attentional influence indicates that the ultra-fast ipsilateral DPOAE adaptation is not solely mediated by the medial olivocochlear reflex.

Virally delivered Channelrhodopsin-2 Safely and Effectively Restores Visual Function in Multiple Mouse Models of Blindness

PubMed Central

Doroudchi, M Mehdi; Greenberg, Kenneth P; Liu, Jianwen; Silka, Kimberly A; Boyden, Edward S; Lockridge, Jennifer A; Arman, A Cyrus; Janani, Ramesh; Boye, Shannon E; Boye, Sanford L; Gordon, Gabriel M; Matteo, Benjamin C; Sampath, Alapakkam P; Hauswirth, William W; Horsager, Alan

2011-01-01

Previous work established retinal expression of channelrhodopsin-2 (ChR2), an algal cation channel gated by light, restored physiological and behavioral visual responses in otherwise blind rd1 mice. However, a viable ChR2-based human therapy must meet several key criteria: (i) ChR2 expression must be targeted, robust, and long-term, (ii) ChR2 must provide long-term and continuous therapeutic efficacy, and (iii) both viral vector delivery and ChR2 expression must be safe. Here, we demonstrate the development of a clinically relevant therapy for late stage retinal degeneration using ChR2. We achieved specific and stable expression of ChR2 in ON bipolar cells using a recombinant adeno-associated viral vector (rAAV) packaged in a tyrosine-mutated capsid. Targeted expression led to ChR2-driven electrophysiological ON responses in postsynaptic retinal ganglion cells and significant improvement in visually guided behavior for multiple models of blindness up to 10 months postinjection. Light levels to elicit visually guided behavioral responses were within the physiological range of cone photoreceptors. Finally, chronic ChR2 expression was nontoxic, with transgene biodistribution limited to the eye. No measurable immune or inflammatory response was observed following intraocular vector administration. Together, these data indicate that virally delivered ChR2 can provide a viable and efficacious clinical therapy for photoreceptor disease-related blindness. PMID:21505421

Rapid and Parallel Adaptive Evolution of the Visual System of Neotropical Midas Cichlid Fishes.

PubMed

Torres-Dowdall, Julián; Pierotti, Michele E R; Härer, Andreas; Karagic, Nidal; Woltering, Joost M; Henning, Frederico; Elmer, Kathryn R; Meyer, Axel

2017-10-01

Midas cichlid fish are a Central American species flock containing 13 described species that has been dated to only a few thousand years old, a historical timescale infrequently associated with speciation. Their radiation involved the colonization of several clear water crater lakes from two turbid great lakes. Therefore, Midas cichlids have been subjected to widely varying photic conditions during their radiation. Being a primary signal relay for information from the environment to the organism, the visual system is under continuing selective pressure and a prime organ system for accumulating adaptive changes during speciation, particularly in the case of dramatic shifts in photic conditions. Here, we characterize the full visual system of Midas cichlids at organismal and genetic levels, to determine what types of adaptive changes evolved within the short time span of their radiation. We show that Midas cichlids have a diverse visual system with unexpectedly high intra- and interspecific variation in color vision sensitivity and lens transmittance. Midas cichlid populations in the clear crater lakes have convergently evolved visual sensitivities shifted toward shorter wavelengths compared with the ancestral populations from the turbid great lakes. This divergence in sensitivity is driven by changes in chromophore usage, differential opsin expression, opsin coexpression, and to a lesser degree by opsin coding sequence variation. The visual system of Midas cichlids has the evolutionary capacity to rapidly integrate multiple adaptations to changing light environments. Our data may indicate that, in early stages of divergence, changes in opsin regulation could precede changes in opsin coding sequence evolution. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Early IGF-1 primes visual cortex maturation and accelerates developmental switch between NKCC1 and KCC2 chloride transporters in enriched animals.

PubMed

Baroncelli, Laura; Cenni, Maria Cristina; Melani, Riccardo; Deidda, Gabriele; Landi, Silvia; Narducci, Roberta; Cancedda, Laura; Maffei, Lamberto; Berardi, Nicoletta

2017-02-01

Environmental enrichment (EE) has a remarkable impact on brain development. Continuous exposure to EE from birth determines a significant acceleration of visual system maturation both at retinal and cortical levels. A pre-weaning enriched experience is sufficient to trigger the accelerated maturation of the visual system, suggesting that factors affected by EE during the first days of life might prime visual circuits towards a faster development. The search for such factors is crucial not only to gain a better understanding of the molecular hierarchy of brain development but also to identify molecular pathways amenable to be targeted to correct atypical brain developmental trajectories. Here, we showed that IGF-1 levels are increased in the visual cortex of EE rats as early as P6 and this is a crucial event for setting in motion the developmental program induced by EE. Early intracerebroventricular (i.c.v.) infusion of IGF-1 in standard rats was sufficient to mimic the action of EE on visual acuity development, whereas blocking IGF-1 signaling by i.c.v. injections of the IGF-1 receptor antagonist JB1 prevented the deployment of EE effects. Early IGF-1 decreased the ratio between the expression of NKCC1 and KCC2 cation/chloride transporters, and the reversal potential for GABA A R-driven Cl - currents (E Cl ) was shifted toward more negative potentials, indicating that IGF-1 is a crucial factor in accelerating the maturation of GABAergic neurotransmission and promoting the developmental switch of GABA polarity from excitation to inhibition. In addition, early IGF-1 promoted a later occurring increase in its own expression, suggesting a priming effect of early IGF-1 in driving post-weaning cortical maturation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Feasibility and Preliminary Efficacy of Visual Cue Training to Improve Adaptability of Walking after Stroke: Multi-Centre, Single-Blind Randomised Control Pilot Trial

PubMed Central

Hollands, Kristen L.; Pelton, Trudy A.; Wimperis, Andrew; Whitham, Diane; Tan, Wei; Jowett, Sue; Sackley, Catherine M.; Wing, Alan M.; Tyson, Sarah F.; Mathias, Jonathan; Hensman, Marianne; van Vliet, Paulette M.

2015-01-01

Objectives Given the importance of vision in the control of walking and evidence indicating varied practice of walking improves mobility outcomes, this study sought to examine the feasibility and preliminary efficacy of varied walking practice in response to visual cues, for the rehabilitation of walking following stroke. Design This 3 arm parallel, multi-centre, assessor blind, randomised control trial was conducted within outpatient neurorehabilitation services Participants Community dwelling stroke survivors with walking speed <0.8m/s, lower limb paresis and no severe visual impairments Intervention Over-ground visual cue training (O-VCT), Treadmill based visual cue training (T-VCT), and Usual care (UC) delivered by physiotherapists twice weekly for 8 weeks. Main outcome measures: Participants were randomised using computer generated random permutated balanced blocks of randomly varying size. Recruitment, retention, adherence, adverse events and mobility and balance were measured before randomisation, post-intervention and at four weeks follow-up. Results Fifty-six participants participated (18 T-VCT, 19 O-VCT, 19 UC). Thirty-four completed treatment and follow-up assessments. Of the participants that completed, adherence was good with 16 treatments provided over (median of) 8.4, 7.5 and 9 weeks for T-VCT, O-VCT and UC respectively. No adverse events were reported. Post-treatment improvements in walking speed, symmetry, balance and functional mobility were seen in all treatment arms. Conclusions Outpatient based treadmill and over-ground walking adaptability practice using visual cues are feasible and may improve mobility and balance. Future studies should continue a carefully phased approach using identified methods to improve retention. Trial Registration Clinicaltrials.gov NCT01600391 PMID:26445137

Remote Infrared Thermography for In-Flight Flow Diagnostics

NASA Technical Reports Server (NTRS)

Shiu, H. J.; vanDam, C. P.

1999-01-01

The feasibility of remote in-flight boundary layer visualization via infrared in incompressible flow was established in earlier flight experiments. The past year's efforts focused on refining and determining the extent and accuracy of this technique of remote in-flight flow visualization via infrared. Investigations were made into flow separation visualization, visualization at transonic conditions, shock visualization, post-processing to mitigate banding noise in the NITE Hawk's thermograms, and a numeric model to predict surface temperature distributions. Although further flight tests are recommended, this technique continues to be promising.

Processing changes across reading encounters.

PubMed

Levy, B A; Newell, S; Snyder, J; Timmins, K

1986-10-01

Five experiments examined changes in the processing of a text across reading encounters. Experiment 1 showed that reading speed increased systematically across encounters, with no loss in the extensiveness of analyses of the printed text, as indicated by the ability to detect nonword errors embedded within that passage. Experiment 2 replicated this improved reading fluency with experience and showed that it occurred even with typescript changes across trials, thus indicating that a primed visual operations explanation cannot account for the effect. The third and fourth experiments then extended the study of the familiarity effect to higher level processing, as indicated by the detection of word errors. Familiarity facilitated the detection of these violations at the syntactic-semantic levels. Finally, Experiment 5 showed that these higher level violations continued to be well detected over a series of reading encounters with the same text. The results indicate that prior experience improves reading speed, with no attenuation of analysis of the printed words or of the passage's message.

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

PubMed

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

2015-09-09

Classical animal visual deprivation studies and human neuroimaging studies have shown that visual experience plays a critical role in shaping the functionality and connectivity of the visual cortex. Interestingly, recent studies have additionally reported circumscribed regions in the visual cortex in which functional selectivity was remarkably similar in individuals with and without visual experience. Here, by directly comparing resting-state and task-based fMRI data in congenitally blind and sighted human subjects, we obtained large-scale continuous maps of the degree to which connectional and functional "fingerprints" of ventral visual cortex depend on visual experience. We found a close agreement between connectional and functional maps, pointing to a strong interdependence of connectivity and function. Visual experience (or the absence thereof) had a pronounced effect on the resting-state connectivity and functional response profile of occipital cortex and the posterior lateral fusiform gyrus. By contrast, connectional and functional fingerprints in the anterior medial and posterior lateral parts of the ventral visual cortex were statistically indistinguishable between blind and sighted individuals. These results provide a large-scale mapping of the influence of visual experience on the development of both functional and connectivity properties of visual cortex, which serves as a basis for the formulation of new hypotheses regarding the functionality and plasticity of specific subregions. Significance statement: How is the functionality and connectivity of the visual cortex shaped by visual experience? By directly comparing resting-state and task-based fMRI data in congenitally blind and sighted subjects, we obtained large-scale continuous maps of the degree to which connectional and functional "fingerprints" of ventral visual cortex depend on visual experience. In addition to revealing regions that are strongly dependent on visual experience (early visual cortex and posterior fusiform gyrus), our results showed regions in which connectional and functional patterns are highly similar in blind and sighted individuals (anterior medial and posterior lateral ventral occipital temporal cortex). These results serve as a basis for the formulation of new hypotheses regarding the functionality and plasticity of specific subregions of the visual cortex. Copyright © 2015 the authors 0270-6474/15/3512545-15$15.00/0.

Fault-Tolerant Control For A Robotic Inspection System

NASA Technical Reports Server (NTRS)

Tso, Kam Sing

1995-01-01

Report describes first phase of continuing program of research on fault-tolerant control subsystem of telerobotic visual-inspection system. Goal of program to develop robotic system for remotely controlled visual inspection of structures in outer space.

Multimodal Communication in a Noisy Environment: A Case Study of the Bornean Rock Frog Staurois parvus

PubMed Central

Grafe, T. Ulmar; Preininger, Doris; Sztatecsny, Marc; Kasah, Rosli; Dehling, J. Maximilian; Proksch, Sebastian; Hödl, Walter

2012-01-01

High background noise is an impediment to signal detection and perception. We report the use of multiple solutions to improve signal perception in the acoustic and visual modality by the Bornean rock frog, Staurois parvus. We discovered that vocal communication was not impaired by continuous abiotic background noise characterised by fast-flowing water. Males modified amplitude, pitch, repetition rate and duration of notes within their advertisement call. The difference in sound pressure between advertisement calls and background noise at the call dominant frequency of 5578 Hz was 8 dB, a difference sufficient for receiver detection. In addition, males used several visual signals to communicate with conspecifics with foot flagging and foot flashing being the most common and conspicuous visual displays, followed by arm waving, upright posture, crouching, and an open-mouth display. We used acoustic playback experiments to test the efficacy-based alerting signal hypothesis of multimodal communication. In support of the alerting hypothesis, we found that acoustic signals and foot flagging are functionally linked with advertisement calling preceding foot flagging. We conclude that S. parvus has solved the problem of continuous broadband low-frequency noise by both modifying its advertisement call in multiple ways and by using numerous visual signals. This is the first example of a frog using multiple acoustic and visual solutions to communicate in an environment characterised by continuous noise. PMID:22655089

Effects of Presentation Type and Visual Control in Numerosity Discrimination: Implications for Number Processing?

PubMed Central

Smets, Karolien; Moors, Pieter; Reynvoet, Bert

2016-01-01

Performance in a non-symbolic comparison task in which participants are asked to indicate the larger numerosity of two dot arrays, is assumed to be supported by the Approximate Number System (ANS). This system allows participants to judge numerosity independently from other visual cues. Supporting this idea, previous studies indicated that numerosity can be processed when visual cues are controlled for. Consequently, distinct types of visual cue control are assumed to be interchangeable. However, a previous study showed that the type of visual cue control affected performance using a simultaneous presentation of the stimuli in numerosity comparison. In the current study, we explored whether the influence of the type of visual cue control on performance disappeared when sequentially presenting each stimulus in numerosity comparison. While the influence of the applied type of visual cue control was significantly more evident in the simultaneous condition, sequentially presenting the stimuli did not completely exclude the influence of distinct types of visual cue control. Altogether, these results indicate that the implicit assumption that it is possible to compare performances across studies with a differential visual cue control is unwarranted and that the influence of the type of visual cue control partly depends on the presentation format of the stimuli. PMID:26869967

Revelations: A Qualitative Inquiry on Visual Artistic Emergence, Common Triggers, Shared Perceptions, and Strategies for Perpetuation

ERIC Educational Resources Information Center

Kobylenski, Steven John

2009-01-01

This research proposal identifies those experiences that lead to the pursuit of visual art as sustained passion in life. In seeking the potential factors that contribute to an individual's continued interest in visual art at key points in their physical maturity and educational lives, strategies for success could be developed for the benefit of…

A Visual Editor in Java for View

NASA Technical Reports Server (NTRS)

Stansifer, Ryan

2000-01-01

In this project we continued the development of a visual editor in the Java programming language to create screens on which to display real-time data. The data comes from the numerous systems monitoring the operation of the space shuttle while on the ground and in space, and from the many tests of subsystems. The data can be displayed on any computer platform running a Java-enabled World Wide Web (WWW) browser and connected to the Internet. Previously a special-purpose program bad been written to display data on emulations of character-based display screens used for many years at NASA. The goal now is to display bit-mapped screens created by a visual editor. We report here on the visual editor that creates the display screens. This project continues the work we bad done previously. Previously we had followed the design of the 'beanbox,' a prototype visual editor created by Sun Microsystems. We abandoned this approach and implemented a prototype using a more direct approach. In addition, our prototype is based on newly released Java 2 graphical user interface (GUI) libraries. The result has been a visually more appealing appearance and a more robust application.

Short-term stability of sleep and heart rate variability in good sleepers and patients with insomnia: for some measures, one night is enough.

PubMed

Israel, Benjamin; Buysse, Daniel J; Krafty, Robert T; Begley, Amy; Miewald, Jean; Hall, Martica

2012-09-01

Quantify the short-term stability of multiple indices of sleep and nocturnal physiology in good sleeper controls and primary insomnia patients. Intra-class correlation coefficients (ICC) were used to quantify the short-term stability of study outcomes. Sleep laboratory. Fifty-four adults with primary insomnia (PI) and 22 good sleeper controls (GSC). Visually scored sleep outcomes included indices of sleep duration, continuity, and architecture. Quantitative EEG outcomes included power in the delta, theta, alpha, sigma, and beta bands during NREM sleep. Power spectral analysis was used to estimate high-frequency heart rate variability (HRV) and the ratio of low- to high-frequency HRV power during NREM and REM sleep. With the exception of percent stage 3+4 sleep; visually scored sleep outcomes did not exhibit short-term stability across study nights. Most QEEG outcomes demonstrated short-term stability in both groups. Although power in the beta band was stable in the PI group (ICC = 0.75), it tended to be less stable in GSCs (ICC = 0.55). Both measures of cardiac autonomic tone exhibited short-term stability in GSCs and PIs during NREM and REM sleep. Most QEEG bandwidths and HRV during sleep show high short-term stability in good sleepers and patients with insomnia alike. One night of data is, thus, sufficient to derive reliable estimates of these outcomes in studies focused on group differences or correlates of QEEG and/or HRV. In contrast, one night of data is unlikely to generate reliable estimates of PSG-assessed sleep duration, continuity or architecture, with the exception of slow wave sleep.

Indications for and outcomes of repeat penetrating keratoplasty, 1989-1995.

PubMed

Patel, N P; Kim, T; Rapuano, C J; Cohen, E J; Laibson, P R

2000-04-01

To evaluate the indications for and outcomes of repeat penetrating keratoplasty over a 7-year period and compare them to a similar study over the prior 6-year period at the same institution. Retrospective noncomparative case series. Two hundred twenty-three consecutive repeat corneal transplants performed by one of five corneal surgeons between 1989 and 1995 were studied. Reasons for primary and regraft failure, indications for the initial corneal graft, graft clarity, and best-corrected visual acuity were measured on each patient. Between 1989 and 1995, 16% (271 of 1689) of transplants performed by our cornea group were regrafts compared with 9% (165 of 1860) in the period from 1983 to 1988 (P < 0.01). The most common indications for penetrating keratoplasty before regraft were pseudophakic bullous keratopathy (27%, 61 of 223), failed graft (20%, 44 of 223), Fuchs' dystrophy (11%, 24 of 223), aphakic bullous keratopathy (9%, 21 of 223), keratoconus (8%, 17 of 223), and herpes simplex keratitis (6%, 14 of 223). Compared with the prior study period of 1983 to 1988, an increase was revealed in the incidence of failed graft (11% to 20%, P = 0.03), and a decrease was revealed in the incidence of aphakic bullous keratopathy (19% to 9%, P = 0.01). Of the 223 regrafts, 55 (25%) failed during the study period (range, 1 month to 7.5 years; mean 2.1 years). Eleven percent (6 of 55) of regraft failures occurred within 6 months, and 55% (30 of 55) failed within 18 months. Of the 150 regrafts with 2 years follow-up (mean, 3.9 years), 111 (74%) had clear grafts. A best-corrected visual acuity of 20/20 to 20/40 was achieved in 41% (46 of 111), 20/50 to 20/100 in 32% (36 of 111), 20/200 to 20/400 in 21% (23 of 111), and counting fingers to no light perception in 5% (6 of 111). Failed grafts are increasing as an indication for penetrating keratoplasty. Graft clarity and visual acuity results continue to be very good, supporting the use of repeat corneal transplantation.

A visual analysis of gender bias in contemporary anatomy textbooks.

PubMed

Parker, Rhiannon; Larkin, Theresa; Cockburn, Jon

2017-05-01

Empirical research has linked gender bias in medical education with negative attitudes and behaviors in healthcare providers. Yet it has been more than 20 years since research has considered the degree to which women and men are equally represented in anatomy textbooks. Furthermore, previous research has not explored beyond quantity of representation to also examine visual gender stereotypes and, in light of theoretical advancements in the area of intersectional research, the relationship between representations of gender and representations of ethnicity, body type, health, and age. This study aimed to determine the existence and representation of gender bias in the major anatomy textbooks used at Australian Medical Schools. A systematic visual content analysis was conducted on 6044 images in which sex/gender could be identified, sourced from 17 major anatomy textbooks published from 2008 to 2013. Further content analysis was performed on the 521 narrative images, which represent an unfolding story, found within the same textbooks. Results indicate that the representation of gender in images from anatomy textbooks remain predominantly male except within sex-specific sections. Further, other forms of bias were found to exist in: the visualization of stereotypical gendered emotions, roles and settings; the lack of ethnic, age, and body type diversity; and in the almost complete adherence to a sex/gender binary. Despite increased attention to gender issues in medicine, the visual representation of gender in medical curricula continues to be biased. The biased construction of gender in anatomy textbooks designed for medical education provides future healthcare providers with inadequate and unrealistic information about patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Visual-vestibular cue integration for heading perception: applications of optimal cue integration theory.

PubMed

Fetsch, Christopher R; Deangelis, Gregory C; Angelaki, Dora E

2010-05-01

The perception of self-motion is crucial for navigation, spatial orientation and motor control. In particular, estimation of one's direction of translation, or heading, relies heavily on multisensory integration in most natural situations. Visual and nonvisual (e.g., vestibular) information can be used to judge heading, but each modality alone is often insufficient for accurate performance. It is not surprising, then, that visual and vestibular signals converge frequently in the nervous system, and that these signals interact in powerful ways at the level of behavior and perception. Early behavioral studies of visual-vestibular interactions consisted mainly of descriptive accounts of perceptual illusions and qualitative estimation tasks, often with conflicting results. In contrast, cue integration research in other modalities has benefited from the application of rigorous psychophysical techniques, guided by normative models that rest on the foundation of ideal-observer analysis and Bayesian decision theory. Here we review recent experiments that have attempted to harness these so-called optimal cue integration models for the study of self-motion perception. Some of these studies used nonhuman primate subjects, enabling direct comparisons between behavioral performance and simultaneously recorded neuronal activity. The results indicate that humans and monkeys can integrate visual and vestibular heading cues in a manner consistent with optimal integration theory, and that single neurons in the dorsal medial superior temporal area show striking correlates of the behavioral effects. This line of research and other applications of normative cue combination models should continue to shed light on mechanisms of self-motion perception and the neuronal basis of multisensory integration.

Long lasting effects of daily theta burst rTMS sessions in the human amblyopic cortex.

PubMed

Clavagnier, Simon; Thompson, Benjamin; Hess, Robert F

2013-11-01

It has been reported that a single session of 1 Hz or 10 Hz repetitive transcranial magnetic stimulation (rTMS) of the visual cortex can temporarily improve contrast sensitivity in adults with amblyopia. More recently, continuous theta burst stimulation (cTBS) of the visual cortex has been found to improve contrast sensitivity in observers with normal vision. The aims of this study were to assess whether cTBS of the visual cortex could improve contrast sensitivity in adults with amblyopia and whether repeated sessions of cTBS would lead to more pronounced and/or longer lasting effects. cTBS was delivered to the visual cortex while patients viewed a high contrast stimulus with their non-amblyopic eye. This manipulation was designed to bias the effects of cTBS toward inputs from the amblyopic eye. Contrast sensitivity was measured before and after stimulation. The effects of one cTBS session were measured in five patients and the effects of five consecutive daily sessions were measured in four patients. Three patients were available for follow-up at varying intervals after the final session. cTBS improved amblyopic eye contrast sensitivity to high spatial frequencies (P < 0.05) and there was a cumulative improvement across sessions with asymptotic improvement occurring after 2 daily sessions of stimulation. The contrast sensitivity improvements were stable over a period of up to 78 days. These initial results in a small number of patients indicate the cTBS may allow for enduring visual function improvements in adults with amblyopia. Copyright © 2013 Elsevier Inc. All rights reserved.

Effect of occlusion amblyopia after prescribed full-time occlusion on long-term visual acuity outcomes.

PubMed

Longmuir, Susannah; Pfeifer, Wanda; Scott, William; Olson, Richard

2013-01-01

To investigate the incidence and characteristics of occlusion amblyopia with prescribed full-time patching and determine its effect on long-term visual acuity outcomes. The records of patients younger than 10 years diagnosed as having amblyopia between 1970 and 2000 were retrospectively reviewed. Patients were prescribed full-time occlusion and observed until completion of therapy. Of 597 patients treated for amblyopia by full-time patching, 115 were diagnosed as having occlusion amblyopia (19.3%). Seventy-five percent (86 of 115) developed occlusion amblyopia during the first episode of full-time patching. Occlusion amblyopia occurred more frequently in children prescribed full-time patching at an earlier age (P = .0002), with an odds ratio of 8.56 (95% confidence interval: 2.73, 26.84) in children younger than 36 months and 2.66 (95% confidence interval: 0.96, 7.37) in children between 36 and 59 months old. Seven of the patients with occlusion amblyopia did not reverse fixation and continued to fixate with the initially amblyopic eye after treatment. Final visual acuity in these eyes with occlusion amblyopia was 20/30 or better. After cessation of treatment, the final interocular difference in visual acuity was less in patients with a history of occlusion amblyopia (P = .003). Occlusion amblyopia occurred at all ages, but the incidence decreased with increasing age. Patients who developed occlusion amblyopia with prescribed full-time occlusion had less interocular visual acuity difference than patients who did not, suggesting that development of occlusion amblyopia can indicate the potential for the development of better vision in the originally amblyopic eye. Copyright 2013, SLACK Incorporated.

Motion/visual cueing requirements for vortex encounters during simulated transport visual approach and landing

NASA Technical Reports Server (NTRS)

Parrish, R. V.; Bowles, R. L.

1983-01-01

This paper addresses the issues of motion/visual cueing fidelity requirements for vortex encounters during simulated transport visual approaches and landings. Four simulator configurations were utilized to provide objective performance measures during simulated vortex penetrations, and subjective comments from pilots were collected. The configurations used were as follows: fixed base with visual degradation (delay), fixed base with no visual degradation, moving base with visual degradation (delay), and moving base with no visual degradation. The statistical comparisons of the objective measures and the subjective pilot opinions indicated that although both minimum visual delay and motion cueing are recommended for the vortex penetration task, the visual-scene delay characteristics were not as significant a fidelity factor as was the presence of motion cues. However, this indication was applicable to a restricted task, and to transport aircraft. Although they were statistically significant, the effects of visual delay and motion cueing on the touchdown-related measures were considered to be of no practical consequence.

Reversible fastener clamp load monitor with continuous visual or remote readout

NASA Astrophysics Data System (ADS)

Hodge, Malcolm H.; Kausel, Theodore C., Jr.; Begley, Matthew R.

1998-03-01

SIMS has developed a simple means for detecting and monitoring both absolute and relative clamp load, or bolt tension, in fastener systems. More than twenty-five percent of automotive failures are known to be due to undetected loss of fastener clamp load. While the equivalent aerospace maintenance statistics are not known, the average automobile has 3,500 fasteners while a Boeing 747 has closer to one million. It is therefore anticipated that the new SensaBolt clamp load tracking system could find wide applications in the aerospace arena. We describe a visually-evident and retrofitted clamp load monitoring design which is based on the differential joint substrate compression at, and immediately adjacent to, the fastener location. This intrinsically-accurate indicator does not necessarily require alteration in either the bolt or nut geometries, thereby facilitating product introduction and retrofit in aging aircraft applications. In addition, SensaBolt's sole reliance on substrate compression renders it more accurate then torque wrench or turn-of-nut techniques. Readout may be accomplished by any of three principal methods: for those applications with ease of access to the sensor, loss of tension can be determined by direct visual inspection. Application of a standard wrench can then be made to restore the fastener's proper tightness, per the SensaBolt indicators. In those instances where line-of-sight is unimpeded and more formal inspection is desired, the SensaBolt may be interrogated by a laser scanner bar code reader. Finally, SensaBolt may be addressed by the SIMS fiber optic harness for those instances where full-time remote interrogation is desired.

Frontoparietal Activation During Visual Conjunction Search: Effects of Bottom-up Guidance and Adult Age

PubMed Central

Madden, David J.; Parks, Emily L.; Tallman, Catherine W.; Boylan, Maria A.; Hoagey, David A.; Cocjin, Sally B.; Johnson, Micah A.; Chou, Ying-hui; Potter, Guy G.; Chen, Nan-kuei; Packard, Lauren E.; Siciliano, Rachel E.; Monge, Zachary A.; Diaz, Michele T.

2016-01-01

We conducted functional magnetic resonance imaging (fMRI) with a visual search paradigm to test the hypothesis that aging is associated with increased frontoparietal involvement in both target detection and bottom-up attentional guidance (featural salience). Participants were 68 healthy adults, distributed continuously across 19-78 years of age. Frontoparietal regions of interest (ROIs) were defined from resting-state scans obtained prior to task-related fMRI. The search target was defined by a conjunction of color and orientation. Each display contained one item that was larger than the others (i.e., a size singleton) but was not informative regarding target identity. Analyses of search reaction time (RT) indicated that bottom-up attentional guidance from the size singleton (when coincident with the target) was relatively constant as a function of age. Frontoparietal fMRI activation related to target detection was constant as a function of age, as was the reduction in activation associated with salient targets. However, for individuals 35 years of age and older, engagement of the left frontal eye field (FEF) in bottom-up guidance was more prominent than for younger individuals. Further, the age-related differences in left FEF activation were a consequence of decreasing resting-state functional connectivity in visual sensory regions. These findings indicate that age-related compensatory effects may be expressed in the relation between activation and behavior, rather than in the magnitude of activation, and that relevant changes in the activation-RT relation may begin at a relatively early point in adulthood. PMID:28052456

Development of a low-cost multiple diode PIV laser for high-speed flow visualization

NASA Astrophysics Data System (ADS)

Bhakta, Raj; Hargather, Michael

2017-11-01

Particle imaging velocimetry (PIV) is an optical visualization technique that typically incorporates a single high-powered laser to illuminate seeded particles in a fluid flow. Standard PIV lasers are extremely costly and have low frequencies that severely limit its capability in high speed, time-resolved imaging. The development of a multiple diode laser system consisting of continuous lasers allows for flexible high-speed imaging with a wider range of test parameters. The developed laser system was fabricated with off-the-shelf parts for approximately 500. A series of experimental tests were conducted to compare the laser apparatus to a standard Nd:YAG double-pulsed PIV laser. Steady and unsteady flows were processed to compare the two systems and validate the accuracy of the multiple laser design. PIV results indicate good correlation between the two laser systems and verifies the construction of a precise laser instrument. The key technical obstacle to this approach was laser calibration and positioning which will be discussed. HDTRA1-14-1-0070.

Foetal images: the power of visual technology in antenatal care and the implications for women's reproductive freedom.

PubMed

Zechmeister, I

2001-01-01

Continuing medico-technical progress has led to an increasing medicalisation of pregnancy and childbirth. One of the most common technologies in this context is ultrasound. Based on some identified 'pro-technology feminist theories', notably the postmodernist feminist discourse, the technology of ultrasound is analysed focusing mainly on social and political rather than clinical issues. As empirical research suggests, ultrasound is welcomed by the majority of women. The analysis, however, shows that attitudes and decisions of women are influenced by broader social aspects. Furthermore, it demonstrates how the visual technology of ultrasound, in addition to other reproductive technology in maternity care, is linked to the 'personification' of the foetus and has therefore contributed to a new image of the foetus. The exploration of these issues challenges some arguments of feminist discourse. It draws attention to possible adverse implications of the technology for women's reproductive freedom and indicates the importance of the topic for political discussions.

Pedagogical efficiency of melodic contour mapping technology as it relates to vocal timbre in singers of classical music repertoire.

PubMed

Barnes-Burroughs, Kathryn; Anderson, Edward E; Hughes, Thomas; Lan, William Y; Dent, Karl; Arnold, Sue; Dolter, Gerald; McNeil, Kathy

2007-11-01

The purpose of this investigation was to ascertain the pedagogical viability of computer-generated melodic contour mapping systems in the classical singing studio, as perceived by their resulting effect (if any) on vocal timbre when a singer's head and neck remained in a normal singing posture. The evaluation of data gathered during the course of the study indicates that the development of consistent vocal timbre produced by the classical singing student may be enhanced through visual/kinesthetic response to melodic contour inversion mapping, as it balances the singer's perception of melodic intervals in standard musical notation. Unexpectedly, it was discovered that the system, in its natural melodic contour mode, may also be useful for teaching a student to sing a consistent legato line. The results of the study also suggest that the continued development of this new technology for the general teaching studio, designed to address standard musical notation and a singer's visual/kinesthetic response to it, may indeed be useful.

The first pictures: perceptual foundations of Paleolithic art.

PubMed

Halverson, J

1992-01-01

Paleolithic representational art has a number of consistent characteristics: the subjects are almost always animals, depicted without scenic background, usually in profile, and mostly in outline; the means of representation are extremely economical, often consisting of only a few strokes that indicate the salient features of the animal which are sufficient to suggest the whole form; and it is naturalistic to a degree, but lacks anything like photographic realism. Two elementary questions are raised in this essay: (i) why did the earliest known attempts at depiction have just these characteristics and not others? and (ii) how are objects so minimally represented recognizable? The answers seem to lie with certain fundamental features of visual perception, especially figure-ground distinction, Gestalt principles of closure and good continuation, line surrogacy, component feature analysis, and canonical imaging. In the earliest pictures the graphic means used are such that they evoke the same visual responses as those involved in the perception of real-world forms, but eschew redundancies of color, texture, linear perspective, and completeness of representation.

Decoding the content of visual short-term memory under distraction in occipital and parietal areas.

PubMed

Bettencourt, Katherine C; Xu, Yaoda

2016-01-01

Recent studies have provided conflicting accounts regarding where in the human brain visual short-term memory (VSTM) content is stored, with strong univariate fMRI responses being reported in superior intraparietal sulcus (IPS), but robust multivariate decoding being reported in occipital cortex. Given the continuous influx of information in everyday vision, VSTM storage under distraction is often required. We found that neither distractor presence nor predictability during the memory delay affected behavioral performance. Similarly, superior IPS exhibited consistent decoding of VSTM content across all distractor manipulations and had multivariate responses that closely tracked behavioral VSTM performance. However, occipital decoding of VSTM content was substantially modulated by distractor presence and predictability. Furthermore, we found no effect of target-distractor similarity on VSTM behavioral performance, further challenging the role of sensory regions in VSTM storage. Overall, consistent with previous univariate findings, our results indicate that superior IPS, but not occipital cortex, has a central role in VSTM storage.

Underwater Flow Visualization Methods in the Upper Layer of the Ocean.

DTIC Science & Technology

1981-05-22

AD-A107 919 NAVAL RESEARCH LAB WASHINGTON DC F/G 8/3 UNDERWATER FLOW VISUALIZATION METHODS IN T1E UPPER LAYER OF THE-ETC(U) AMAY 81 J R MCGRATH, C M...S.bOti1.) S. TYPE OF REPORT I PERIOD COVERED UNDERWATER FLOW VISUALIZATION METHODS Interim report on a continuingNRL problem. IN THE UPPER LAYER OF THE...56 UNDERWATER FLOW VISUALIZATION METHODS IN THE UPPER LAYER OF THE OCEAN 1. INTRODUCTION a) Purpose This report documents the

Usefulness and Validity of Continuous Performance Tests in the Diagnosis of Attention-Deficit Hyperactivity Disorder Children.

PubMed

Berger, Itai; Slobodin, Ortal; Cassuto, Hanoch

2017-02-01

Despite the popularity of continuous performance tests (CPT) in supporting the diagnostic procedure of attention-deficit hyperactivity disorder (ADHD), these measures are still controversial mainly due to limited sensitivity, specificity, and ecological validity. Thus, there continues to be a need for further validation of these objective attention measures. The purpose of this study was to evaluate the usefulness of a CPT that includes environmental distracting stimuli, in supporting the diagnosis of ADHD in children. Participants were 798 children aged 7-12 years (493 boys and 305 girls). The ADHD group included 339 children, whereas the control group included 459 children without ADHD. The study employed the MOXO-CPT, which incorporates visual and auditory stimuli serving as environmental distractors. Compared to their unaffected peers, children with ADHD received significantly lower scores in all 4 CPT indices: attention, timing, hyperactivity, and impulsivity. Specifically, ADHD children were less attended to the stimuli and performed fewer reactions on accurate timing. Furthermore, children with ADHD performed significantly more impulsive and hyperactive responses than controls. Receiver operating characteristic analysis revealed fair to excellent diagnostic ability of all CPT indices except impulsivity, which showed poor ability to distinguish ADHD children from controls. The test's total score yielded excellent diagnostic performance. MOXO-CPT consistently distinguished between children with ADHD and their unaffected peers, so that children with ADHD performed worse than controls in all study indices. Integration of CPT indices improves the diagnostic capacity of ADHD and may better reflect the complexity and heterogeneity of ADHD. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Out of sight but not out of mind: the neurophysiology of iconic memory in the superior temporal sulcus.

PubMed

Keysers, C; Xiao, D-K; Foldiak, P; Perrett, D I

2005-05-01

Iconic memory, the short-lasting visual memory of a briefly flashed stimulus, is an important component of most models of visual perception. Here we investigate what physiological mechanisms underlie this capacity by showing rapid serial visual presentation (RSVP) sequences with and without interstimulus gaps to human observers and macaque monkeys. For gaps of up to 93 ms between consecutive images, human observers and neurones in the temporal cortex of macaque monkeys were found to continue processing a stimulus as if it was still present on the screen. The continued firing of neurones in temporal cortex may therefore underlie iconic memory. Based on these findings, a neurophysiological vision of iconic memory is presented.

Improving exposure assessment in environmental epidemiology: Application of spatio-temporal visualization tools

NASA Astrophysics Data System (ADS)

Meliker, Jaymie R.; Slotnick, Melissa J.; Avruskin, Gillian A.; Kaufmann, Andrew; Jacquez, Geoffrey M.; Nriagu, Jerome O.

2005-05-01

A thorough assessment of human exposure to environmental agents should incorporate mobility patterns and temporal changes in human behaviors and concentrations of contaminants; yet the temporal dimension is often under-emphasized in exposure assessment endeavors, due in part to insufficient tools for visualizing and examining temporal datasets. Spatio-temporal visualization tools are valuable for integrating a temporal component, thus allowing for examination of continuous exposure histories in environmental epidemiologic investigations. An application of these tools to a bladder cancer case-control study in Michigan illustrates continuous exposure life-lines and maps that display smooth, continuous changes over time. Preliminary results suggest increased risk of bladder cancer from combined exposure to arsenic in drinking water (>25 μg/day) and heavy smoking (>30 cigarettes/day) in the 1970s and 1980s, and a possible cancer cluster around automotive, paint, and organic chemical industries in the early 1970s. These tools have broad application for examining spatially- and temporally-specific relationships between exposures to environmental risk factors and disease.

A unified account of tilt illusions, association fields, and contour detection based on elastica.

PubMed

Keemink, Sander W; van Rossum, Mark C W

2016-09-01

As expressed in the Gestalt law of good continuation, human perception tends to associate stimuli that form smooth continuations. Contextual modulation in primary visual cortex, in the form of association fields, is believed to play an important role in this process. Yet a unified and principled account of the good continuation law on the neural level is lacking. In this study we introduce a population model of primary visual cortex. Its contextual interactions depend on the elastica curvature energy of the smoothest contour connecting oriented bars. As expected, this model leads to association fields consistent with data. However, in addition the model displays tilt-illusions for stimulus configurations with grating and single bars that closely match psychophysics. Furthermore, the model explains not only pop-out of contours amid a variety of backgrounds, but also pop-out of single targets amid a uniform background. We thus propose that elastica is a unifying principle of the visual cortical network. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Odors Bias Time Perception in Visual and Auditory Modalities

PubMed Central

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

2016-01-01

Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal) were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor). The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a framework of attentional deployment between the inducers (odors) and emotionally neutral stimuli (visual dots and sound beeps). PMID:27148143

Perception of visual apparent motion is modulated by a gap within concurrent auditory glides, even when it is illusory

PubMed Central

Wang, Qingcui; Guo, Lu; Bao, Ming; Chen, Lihan

2015-01-01

Auditory and visual events often happen concurrently, and how they group together can have a strong effect on what is perceived. We investigated whether/how intra- or cross-modal temporal grouping influenced the perceptual decision of otherwise ambiguous visual apparent motion. To achieve this, we juxtaposed auditory gap transfer illusion with visual Ternus display. The Ternus display involves a multi-element stimulus that can induce either of two different percepts of apparent motion: ‘element motion’ (EM) or ‘group motion’ (GM). In “EM,” the endmost disk is seen as moving back and forth while the middle disk at the central position remains stationary; while in “GM,” both disks appear to move laterally as a whole. The gap transfer illusion refers to the illusory subjective transfer of a short gap (around 100 ms) from the long glide to the short continuous glide when the two glides intercede at the temporal middle point. In our experiments, observers were required to make a perceptual discrimination of Ternus motion in the presence of concurrent auditory glides (with or without a gap inside). Results showed that a gap within a short glide imposed a remarkable effect on separating visual events, and led to a dominant perception of GM as well. The auditory configuration with gap transfer illusion triggered the same auditory capture effect. Further investigations showed that visual interval which coincided with the gap interval (50–230 ms) in the long glide was perceived to be shorter than that within both the short glide and the ‘gap-transfer’ auditory configurations in the same physical intervals (gaps). The results indicated that auditory temporal perceptual grouping takes priority over the cross-modal interaction in determining the final readout of the visual perception, and the mechanism of selective attention on auditory events also plays a role. PMID:26042055

Perception of visual apparent motion is modulated by a gap within concurrent auditory glides, even when it is illusory.

PubMed

Wang, Qingcui; Guo, Lu; Bao, Ming; Chen, Lihan

2015-01-01

Auditory and visual events often happen concurrently, and how they group together can have a strong effect on what is perceived. We investigated whether/how intra- or cross-modal temporal grouping influenced the perceptual decision of otherwise ambiguous visual apparent motion. To achieve this, we juxtaposed auditory gap transfer illusion with visual Ternus display. The Ternus display involves a multi-element stimulus that can induce either of two different percepts of apparent motion: 'element motion' (EM) or 'group motion' (GM). In "EM," the endmost disk is seen as moving back and forth while the middle disk at the central position remains stationary; while in "GM," both disks appear to move laterally as a whole. The gap transfer illusion refers to the illusory subjective transfer of a short gap (around 100 ms) from the long glide to the short continuous glide when the two glides intercede at the temporal middle point. In our experiments, observers were required to make a perceptual discrimination of Ternus motion in the presence of concurrent auditory glides (with or without a gap inside). Results showed that a gap within a short glide imposed a remarkable effect on separating visual events, and led to a dominant perception of GM as well. The auditory configuration with gap transfer illusion triggered the same auditory capture effect. Further investigations showed that visual interval which coincided with the gap interval (50-230 ms) in the long glide was perceived to be shorter than that within both the short glide and the 'gap-transfer' auditory configurations in the same physical intervals (gaps). The results indicated that auditory temporal perceptual grouping takes priority over the cross-modal interaction in determining the final readout of the visual perception, and the mechanism of selective attention on auditory events also plays a role.

Beyond a mask and against the bottleneck: retroactive dual-task interference during working memory consolidation of a masked visual target.

PubMed

Nieuwenstein, Mark; Wyble, Brad

2014-06-01

While studies on visual memory commonly assume that the consolidation of a visual stimulus into working memory is interrupted by a trailing mask, studies on dual-task interference suggest that the consolidation of a stimulus can continue for several hundred milliseconds after a mask. As a result, estimates of the time course of working memory consolidation differ more than an order of magnitude. Here, we contrasted these opposing views by examining if and for how long the processing of a masked display of visual stimuli can be disturbed by a trailing 2-alternative forced choice task (2-AFC; a color discrimination task or a visual or auditory parity judgment task). The results showed that the presence of the 2-AFC task produced a pronounced retroactive interference effect that dissipated across stimulus onset asynchronies of 250-1,000 ms, indicating that the processing elicited by the 2-AFC task interfered with the gradual consolidation of the earlier shown stimuli. Furthermore, this interference effect occurred regardless of whether the to-be-remembered stimuli comprised a string of letters or an unfamiliar complex visual shape, and it occurred regardless of whether these stimuli were masked. Conversely, the interference effect was reduced when the memory load for the 1st task was reduced, or when the 2nd task was a color detection task that did not require decision making. Taken together, these findings show that the formation of a durable and consciously accessible working memory trace for a briefly shown visual stimulus can be disturbed by a trailing 2-AFC task for up to several hundred milliseconds after the stimulus has been masked. By implication, the current findings challenge the common view that working memory consolidation involves an immutable central processing bottleneck, and they also make clear that consolidation does not stop when a stimulus is masked. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Detection Progress of Selected Drugs in TLC

PubMed Central

Pyka, Alina

2014-01-01

This entry describes applications of known indicators and dyes as new visualizing reagents and various visualizing systems as well as photocatalytic reactions and bioautography method for the detection of bioactive compounds including drugs and compounds isolated from herbal extracts. Broadening index, detection index, characteristics of densitometric band, modified contrast index, limit of detection, densitometric visualizing index, and linearity range of detected compounds were used for the evaluation of visualizing effects of applied visualizing reagents. It was shown that visualizing effect depends on the chemical structure of the visualizing reagent, the structure of the substance detected, and the chromatographic adsorbent applied. The usefulness of densitometry to direct detection of some drugs was also shown. Quoted papers indicate the detection progress of selected drugs investigated by thin-layer chromatography (TLC). PMID:24551853

40 CFR 63.7830 - What are my monitoring requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... equivalent means. (vi) Make monthly visual checks of bag tension on reverse air and shaker-type baghouses to....7830 Section 63.7830 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED...

Cross-sectional echocardiographic diagnosis of azygos continuation of the inferior vena cava.

PubMed

Huhta, J C; Smallhorn, J F; Macartney, F J

1984-01-01

Azygos continuation of the inferior vena cava has importance for both the invasive diagnosis of congenital heart disease by catheterization and for surgical treatment. Cross-sectional echocardiography was used to examine 1,000 patients (1 day to 16 years, mean 3.3 years) who also had angiographic or surgical confirmation. Twenty-eight patients (3%) had azygos continuation (left 13, right 14, bilateral 1) and, in 26 patients, the hepatic portion of the inferior vena cava was absent. Azygos continuation was prospectively detected in all and was directly visualized in subcostal scans as a venous structure posterior to the aorta coursing behind the heart and not entering the inferior aspect of either atrium in 26/28 (93%). Azygos connection to the ipsilateral superior vena cava or atrium was correctly predicted in all. The inferior vena cava was visualized in all patients without azygos continuation, except one neonate with omphalocele. We conclude that cross-sectional echocardiography can accurately detect azygos continuation of the inferior vena cava and predict its side and connection.

Genotype-Phenotype Analysis, Neuropsychological Assessment, and Growth Hormone Response in a Patient with 18p Deletion Syndrome.

PubMed

Sun, Huihui; Wan, Naijun; Wang, Xinli; Chang, Liang; Cheng, Dazhi

2018-01-01

18p deletion syndrome is a rare chromosomal disease caused by deletion of the short arm of chromosome 18. By using cytogenetic and SNP array analysis, we identified a girl with 18p deletion syndrome exhibiting craniofacial anomalies, intellectual disability, and short stature. G-banding analysis of metaphase cells revealed an abnormal karyotype 46,XX,del(18)(p10). Further, SNP array detected a 15.3-Mb deletion at 18p11.21p11.32 (chr18:12842-15375878) including 61 OMIM genes. Genotype-phenotype correlation analysis showed that clinical manifestations of the patient were correlated with LAMA1, TWSG1, and GNAL deletions. Her neuropsychological assessment test demonstrated delay in most cognitive functions including impaired mathematics, linguistic skills, visual motor perception, respond speed, and executive function. Meanwhile, her integrated visual and auditory continuous performance test (IVA-CPT) indicated a severe comprehensive attention deficit. At age 7 and 1/12 years, her height was 110.8 cm (-2.5 SD height for age). Growth hormone (GH) treatment was initiated. After 27 months treatment, her height was increased to 129.6 cm (-1.0 SD height for age) at 9 and 4/12 years, indicating an effective response to GH treatment. © 2018 S. Karger AG, Basel.

Retinal vessel caliber among people with acquired immunodeficiency syndrome: relationships with visual function.

PubMed

Kalyani, Partho S; Fawzi, Amani A; Gangaputra, Sapna; van Natta, Mark L; Hubbard, Larry D; Danis, Ronald P; Thorne, Jennifer E; Holland, Gary N

2012-03-01

To evaluate relationships between retinal vessel caliber and tests of visual function among people with AIDS. Longitudinal, observational cohort study. We evaluated data for participants without ocular opportunistic infections at initial examination (baseline) in the Longitudinal Studies of the Ocular Complications of AIDS (1998-2008). Visual function was evaluated with best-corrected visual acuity, Goldmann perimetry, automated perimetry (Humphrey Field Analyzer), and contrast sensitivity (CS) testing. Semi-automated grading of fundus photographs (1 eye/participant) determined central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and arteriole-to-venule ratio (AVR) at baseline. Multiple linear regression models, using forward selection, sought independent relationships between indices and visual function variables. Included were 1250 participants. Smaller AVR was associated with reduced visual field by Goldmann perimetry (P = .003) and worse mean deviation (P = .02) on automated perimetry and possibly with worse pattern standard deviation (PSD) on automated perimetry (P = .06). There was a weak association between smaller AVR and worse CS (P = .07). Relationships were independent of antiretroviral therapy and level of immunodeficiency (CD4+ T lymphocyte count, human immunodeficiency virus [HIV] RNA blood level). On longitudinal analysis, retinal vascular indices at baseline did not predict changes in visual function. Variation in retinal vascular indices is associated with abnormal visual function in people with AIDS, manifested by visual field loss and possibly by reduced CS. Relationships are consistent with the hypothesis that HIV-related retinal vasculopathy is a contributing factor to vision dysfunction among HIV-infected individuals. Longitudinal studies are needed to determine whether changes in indices predict change in visual function. Copyright © 2012 Elsevier Inc. All rights reserved.

Lean management: innovative tools for engaging teams in continuous quality improvement.

PubMed

Perreault, Lucille; Vaillancourt, Lise; Filion, Catherine; Hadj, Camélia

2014-01-01

Lean management has proven to be a sustainable method to ensure a high level of patient care through innovation and teamwork. It involves a set of six tools that allow for visual management shared among team members. The team focuses their efforts on the improvement of organizational indicators in a standardized and engaging way, resulting in the sustainability of improvements. This article outlines the program's rollout at Montfort Hospital (l'Hôpital Montfort). In only a few months, two pilot units accomplished close to 50 improvements each. In addition, the organizational employee satisfaction questionnaire showed very positive results. Copyright © 2014 Longwoods Publishing.

Relationship of prior knowledge and working engineers' learning preferences: implications for designing effective instruction

NASA Astrophysics Data System (ADS)

Baukal, Charles E.; Ausburn, Lynna J.

2017-05-01

Continuing engineering education (CEE) is important to ensure engineers maintain proficiency over the life of their careers. However, relatively few studies have examined designing effective training for working engineers. Research has indicated that both learner instructional preferences and prior knowledge can impact the learning process, but it has not established if these factors are interrelated. The study reported here considered relationships of prior knowledge and three aspects of learning preferences of working engineers at a manufacturing company: learning strategy choices, verbal-visual cognitive styles, and multimedia preferences. Prior knowledge was not found to be significantly related to engineers' learning preferences, indicating independence of effects of these variables on learning. The study also examined relationships of this finding to the Multimedia Cone of Abstraction and implications for its use as an instructional design tool for CEE.

Enhancement of KTP/532 laser disc decompression and arthroscopic microdiscectomy with a vital dye

NASA Astrophysics Data System (ADS)

Yeung, Anthony T.

1993-07-01

Currently, the clinical indications and results of arthroscopic microdiscectomy and laser disc decompression come close to, but do not exceed, the results of classic discectomy or microdiscectomy for the whole spectrum of surgical disc herniations. However, as minimally invasive techniques continue to evolve, results can be expected to equal or be potentially superior to conventional surgery. This exhibit demonstrates how the use of a vital dye can enhance standard arthroscopic microdiscectomy techniques and, when used in conjunction with KTP/532 laser disc decompression, allows for better arthroscopic visualization, documentation, and extraction of nucleus pulposus, ultimately expanding the current limiting criteria for minimally invasive techniques. When proper patient selection is combined with good clinical indications, the surgical results are rather dramatic, often achieving immediate relief of sciatica in the operating room.

Objective Analysis of Performance of Activities of Daily Living in People With Central Field Loss.

PubMed

Pardhan, Shahina; Latham, Keziah; Tabrett, Daryl; Timmis, Matthew A

2015-11-01

People with central visual field loss (CFL) adopt various strategies to complete activities of daily living (ADL). Using objective movement analysis, we compared how three ADLs were completed by people with CFL compared with age-matched, visually healthy individuals. Fourteen participants with CFL (age 81 ± 10 years) and 10 age-matched, visually healthy (age 75 ± 5 years) participated. Three ADLs were assessed: pick up food from a plate, pour liquid from a bottle, and insert a key in a lock. Participants with CFL completed each ADL habitually (as they would in their home). Data were compared with visually healthy participants who were asked to complete the tasks as they would normally, but under specified experimental conditions. Movement kinematics were compared using three-dimension motion analysis (Vicon). Visual functions (distance and near acuities, contrast sensitivity, visual fields) were recorded. All CFL participants were able to complete each ADL. However, participants with CFL demonstrated significantly (P < 0.05) longer overall movement times, shorter minimum viewing distance, and, for two of the three ADL tasks, needed more online corrections in the latter part of the movement. Results indicate that, despite the adoption of various habitual strategies, participants with CFL still do not perform common daily living tasks as efficiently as healthy subjects. Although indices suggesting feed-forward planning are similar, they made more movement corrections and increased time for the latter portion of the action, indicating a more cautious/uncertain approach. Various kinematic indices correlated significantly to visual function parameters including visual acuity and midperipheral visual field loss.

Long-term follow-up of patients with retinitis pigmentosa (RP) receiving intraocular ciliary neurotrophic factor implants

PubMed Central

Birch, David G.; Bennett, Lea D.; Duncan, Jacque L.; Weleber, Richard G.; Pennesi, Mark E.

2016-01-01

Purpose To evaluate the long-term efficacy of ciliary neurotrophic factor delivered via an intraocular encapsulated cell implant for the treatment of retinitis pigmentosa (RP). Design Long-term follow up of a multicenter, sham-controlled study. Methods Thirty-six patients at three CNTF4 sites were randomly assigned to receive a high- or low- dose implant in one eye and sham surgery in the fellow eye. The primary endpoint (change in visual field sensitivity at 12 months) has been reported previously.1 Here we report long-term visual acuity, visual field and optical coherence tomography (OCT) outcomes in 24 patients either retaining or explanting the device at 24 months relative to sham-treated eyes. Results Eyes retaining the implant showed significantly greater visual field loss from baseline than either explanted eyes or sham eyes through 42 months. By 60 months and continuing through 96 months, visual field loss was comparable among sham-treated eyes, eyes retaining the implant and explanted eyes, as was visual acuity and OCT macular volume. Conclusions Over the short term, ciliary neurotrophic factor released continuously from an intra-vitreal implant lead to loss of total visual field sensitivity that was greater than the natural progression in the sham-treated eye. This additional loss of sensitivity related to the active implant was reversible when the implant was removed. Over the long term (60 – 96 months), there was no evidence of efficacy for visual acuity, visual field sensitivity or OCT measures of retinal structure. PMID:27457255

Visual speech influences speech perception immediately but not automatically.

PubMed

Mitterer, Holger; Reinisch, Eva

2017-02-01

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

Weighted feature selection criteria for visual servoing of a telerobot

NASA Technical Reports Server (NTRS)

Feddema, John T.; Lee, C. S. G.; Mitchell, O. R.

1989-01-01

Because of the continually changing environment of a space station, visual feedback is a vital element of a telerobotic system. A real time visual servoing system would allow a telerobot to track and manipulate randomly moving objects. Methodologies for the automatic selection of image features to be used to visually control the relative position between an eye-in-hand telerobot and a known object are devised. A weighted criteria function with both image recognition and control components is used to select the combination of image features which provides the best control. Simulation and experimental results of a PUMA robot arm visually tracking a randomly moving carburetor gasket with a visual update time of 70 milliseconds are discussed.

Using Visualization Science to Evaluate Effective Communication of Climate Indicators

NASA Astrophysics Data System (ADS)

Gerst, M.; Kenney, M. A.; Wolfinger, F.; Lloyd, A.

2015-12-01

Indicators are observations or calculations that are used to track social and environmental conditions over time. For a large coupled system such as the economy and environment, the choice of indicators requires a structured process that involves co-production among facilitators, subject-matter experts, decision-makers, and the general public. This co-production is needed in part because such indicators serve a duel role of scientifically tracking change and of communicating to non-scientists important changes and information that may be useful in decision contexts. Because the goal is to communicate and inform decisions it is critical that indicators be understood by non-scientific audiences, which may require different visualization techniques than for scientific audiences. Here we describe a process of rigorously evaluating visual communication efficacy by using a simplified taxonomy of visualization design problems and trade-offs to assess existing and redesigned indicator images. The experimental design is three-part. It involves testing non-scientific audiences' understandability of scientific images found in the literature along with similar information shaped by a partial co-production process that informed the U.S. Global Change Research Program prototype indicators system, released in Spring 2015. These recommendations for physical, natural, and societal indicators of changes and impacts involved input from over 200 subject-matter experts, organized into 13 technical teams. Using results from the first two parts, we then explore visualization design improvements that may increase understandability to non-scientific audiences. We anticipate that this work will highlight important trade-offs in visualization design when moving between audiences that will be of great use to scientists who wish to communicate their results broader audiences.

Visualization of volumetric seismic data

NASA Astrophysics Data System (ADS)

Spickermann, Dela; Böttinger, Michael; Ashfaq Ahmed, Khawar; Gajewski, Dirk

2015-04-01

Mostly driven by demands of high quality subsurface imaging, highly specialized tools and methods have been developed to support the processing, visualization and interpretation of seismic data. 3D seismic data acquisition and 4D time-lapse seismic monitoring are well-established techniques in academia and industry, producing large amounts of data to be processed, visualized and interpreted. In this context, interactive 3D visualization methods proved to be valuable for the analysis of 3D seismic data cubes - especially for sedimentary environments with continuous horizons. In crystalline and hard rock environments, where hydraulic stimulation techniques may be applied to produce geothermal energy, interpretation of the seismic data is a more challenging problem. Instead of continuous reflection horizons, the imaging targets are often steep dipping faults, causing a lot of diffractions. Without further preprocessing these geological structures are often hidden behind the noise in the data. In this PICO presentation we will present a workflow consisting of data processing steps, which enhance the signal-to-noise ratio, followed by a visualization step based on the use the commercially available general purpose 3D visualization system Avizo. Specifically, we have used Avizo Earth, an extension to Avizo, which supports the import of seismic data in SEG-Y format and offers easy access to state-of-the-art 3D visualization methods at interactive frame rates, even for large seismic data cubes. In seismic interpretation using visualization, interactivity is a key requirement for understanding complex 3D structures. In order to enable an easy communication of the insights gained during the interactive visualization process, animations of the visualized data were created which support the spatial understanding of the data.

Indications and Visual Outcome of Penetrating Keratoplasty in Tertiary Eye Care Institute in Uttarakhand

PubMed Central

Gupta, Neeti; Dhasmana, Renu; Nagpal, Ramesh Chander; Bahadur, Harsh; Maitreya, Amit

2016-01-01

Introduction Corneal blindness forms significant proportion of visual blindness in developing countries and penetrating keratoplasty (PK) can restore vision for this. The prognosis of PK is dependent on the corneal diseases responsible for corneal blindness. Aim To evaluate the indications and visual outcome of PK in tertiary eye care institute in Uttarakhand. Materials and Methods Data was reviewed from the medical records of 145 PK done in Department of Ophthalmology, Himalayan Institute of Medical Sciences from January 2012 to October 2014. Analysis of data was done for evaluation of the indications and visual outcome by Paired student’s t-test for hypothesis testing of grouped values of preoperative and last follow-up best corrected visual acuity in cases of optical and therapeutic grafts. A p-value < 0.05 was considered statistically significant. Results In this study data of 145 eyes of 138 patients was reviewed. The most common indication for keratoplasty was corneal scarring including adherent leucoma 48 (33.10%). Therapeutic keratoplasty was done for 33 cases with maximum 30(20.68%) cases of infectious keratitis. One case of tectonic graft was included in therapeutic keratoplasty group for analysis. There was statistically significant difference (p=.0001) in best corrected visual acuity improvement from 1.39 logMAR+ 0.022(SD) preoperatively to 0.367 logMAR+0.44(SD) postoperatively and 1.4 logMAR+.000(SD) preoperatively to 0.16 logMAR+0.57(SD) postoperatively for optical and therapeutic grafts respectively. Conclusion Infective keratitis either active or healed was the major indication for keratoplasty. Poor prognosis indications were most common in this part of the country. The visual outcome following corneal transplantation was encouraging particularly in cases of optical keratoplasty. PMID:27504319

38 CFR 4.75 - General considerations for evaluating visual impairment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... refraction), visual field, and muscle function. (b) Examination for visual impairment. The examination must.... Examinations of visual fields or muscle function will be conducted only when there is a medical indication of disease or injury that may be associated with visual field defect or impaired muscle function. Unless...

38 CFR 4.75 - General considerations for evaluating visual impairment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... refraction), visual field, and muscle function. (b) Examination for visual impairment. The examination must.... Examinations of visual fields or muscle function will be conducted only when there is a medical indication of disease or injury that may be associated with visual field defect or impaired muscle function. Unless...

38 CFR 4.75 - General considerations for evaluating visual impairment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... refraction), visual field, and muscle function. (b) Examination for visual impairment. The examination must.... Examinations of visual fields or muscle function will be conducted only when there is a medical indication of disease or injury that may be associated with visual field defect or impaired muscle function. Unless...

Diabetes ongoing sustainable care and treatment (DOST): A strategy for informational deliverance through visual dynamic modules sustained by near peer mentoring.

PubMed

Joshi, Ankur; Arutagi, Vishwanath; Nahar, Nitin; Tiwari, Sharad; Singh, Daneshwar; Sethia, Soumitra

2016-01-01

The informational continuity for a diabetic patient is of paramount importance. This study on a pilot basis explores the process utility of structured educational modular sessions grounded on the principle of near-peer mentoring. Visual modules were prepared for diabetic patients. These modules were instituted to 25 diabetic patients in logical sequences. In the next phase, 4 persons of these 25 patients were designated as diabetic-diabetes ongoing sustainable care and treatment (DOST). Each diabetic-DOST was clubbed with two patients for modular session and informational deliverance during the next 7 days. Process analysis was performed with "proxy-indicators," namely, monthly glycemic status, knowledge assessment scores, and quality of life. Data were analyzed by interval estimates and through nonparametric analysis. Nonparametric analysis indicated a significant improvement in glycemic status in terms with fasting blood sugar (W = 78 z = 3.04, P = 0.002), 2 h-postprandial blood sugar (W = 54, z = 2.01, P = 0.035), and in knowledge score (χ 2 = 19.53, df = 3; P = 0.0002). Quality of life score showed significant improvement in 2 out of 7 domains, namely, satisfaction with treatment ([difference in mean score = 1.40 [1.94 to 0.85]) and symptom botherness (difference in mean score = 0.98 [1.3-0.65]). Because of inherent methodological limitations and innate biases, at this juncture no conclusive statement can be drawn. Although, primitive process evidences indicate the promising role of the diabetic-DOST strategy.

Sustained Attention in Real Classroom Settings: An EEG Study.

PubMed

Ko, Li-Wei; Komarov, Oleksii; Hairston, W David; Jung, Tzyy-Ping; Lin, Chin-Teng

2017-01-01

Sustained attention is a process that enables the maintenance of response persistence and continuous effort over extended periods of time. Performing attention-related tasks in real life involves the need to ignore a variety of distractions and inhibit attention shifts to irrelevant activities. This study investigates electroencephalography (EEG) spectral changes during a sustained attention task within a real classroom environment. Eighteen healthy students were instructed to recognize as fast as possible special visual targets that were displayed during regular university lectures. Sorting their EEG spectra with respect to response times, which indicated the level of visual alertness to randomly introduced visual stimuli, revealed significant changes in the brain oscillation patterns. The results of power-frequency analysis demonstrated a relationship between variations in the EEG spectral dynamics and impaired performance in the sustained attention task. Across subjects and sessions, prolongation of the response time was preceded by an increase in the delta and theta EEG powers over the occipital region, and decrease in the beta power over the occipital and temporal regions. Meanwhile, implementation of the complex attention task paradigm into a real-world classroom setting makes it possible to investigate specific mutual links between brain activities and factors that cause impaired behavioral performance, such as development and manifestation of classroom mental fatigue. The findings of the study set a basis for developing a system capable of estimating the level of visual attention during real classroom activities by monitoring changes in the EEG spectra.

Sustained Attention in Real Classroom Settings: An EEG Study

PubMed Central

Ko, Li-Wei; Komarov, Oleksii; Hairston, W. David; Jung, Tzyy-Ping; Lin, Chin-Teng

2017-01-01

Sustained attention is a process that enables the maintenance of response persistence and continuous effort over extended periods of time. Performing attention-related tasks in real life involves the need to ignore a variety of distractions and inhibit attention shifts to irrelevant activities. This study investigates electroencephalography (EEG) spectral changes during a sustained attention task within a real classroom environment. Eighteen healthy students were instructed to recognize as fast as possible special visual targets that were displayed during regular university lectures. Sorting their EEG spectra with respect to response times, which indicated the level of visual alertness to randomly introduced visual stimuli, revealed significant changes in the brain oscillation patterns. The results of power-frequency analysis demonstrated a relationship between variations in the EEG spectral dynamics and impaired performance in the sustained attention task. Across subjects and sessions, prolongation of the response time was preceded by an increase in the delta and theta EEG powers over the occipital region, and decrease in the beta power over the occipital and temporal regions. Meanwhile, implementation of the complex attention task paradigm into a real-world classroom setting makes it possible to investigate specific mutual links between brain activities and factors that cause impaired behavioral performance, such as development and manifestation of classroom mental fatigue. The findings of the study set a basis for developing a system capable of estimating the level of visual attention during real classroom activities by monitoring changes in the EEG spectra. PMID:28824396

Picture naming in typically developing and language-impaired children: the role of sustained attention.

PubMed

Jongman, Suzanne R; Roelofs, Ardi; Scheper, Annette R; Meyer, Antje S

2017-05-01

Children with specific language impairment (SLI) have problems not only with language performance but also with sustained attention, which is the ability to maintain alertness over an extended period of time. Although there is consensus that this ability is impaired with respect to processing stimuli in the auditory perceptual modality, conflicting evidence exists concerning the visual modality. To address the outstanding issue whether the impairment in sustained attention is limited to the auditory domain, or if it is domain-general. Furthermore, to test whether children's sustained attention ability relates to their word-production skills. Groups of 7-9 year olds with SLI (N = 28) and typically developing (TD) children (N = 22) performed a picture-naming task and two sustained attention tasks, namely auditory and visual continuous performance tasks (CPTs). Children with SLI performed worse than TD children on picture naming and on both the auditory and visual CPTs. Moreover, performance on both the CPTs correlated with picture-naming latencies across developmental groups. These results provide evidence for a deficit in both auditory and visual sustained attention in children with SLI. Moreover, the study indicates there is a relationship between domain-general sustained attention and picture-naming performance in both TD and language-impaired children. Future studies should establish whether this relationship is causal. If attention influences language, training of sustained attention may improve language production in children from both developmental groups. © 2016 Royal College of Speech and Language Therapists.

Modulation of brain activity by multiple lexical and word form variables in visual word recognition: A parametric fMRI study.

PubMed

Hauk, Olaf; Davis, Matthew H; Pulvermüller, Friedemann

2008-09-01

Psycholinguistic research has documented a range of variables that influence visual word recognition performance. Many of these variables are highly intercorrelated. Most previous studies have used factorial designs, which do not exploit the full range of values available for continuous variables, and are prone to skewed stimulus selection as well as to effects of the baseline (e.g. when contrasting words with pseudowords). In our study, we used a parametric approach to study the effects of several psycholinguistic variables on brain activation. We focussed on the variable word frequency, which has been used in numerous previous behavioural, electrophysiological and neuroimaging studies, in order to investigate the neuronal network underlying visual word processing. Furthermore, we investigated the variable orthographic typicality as well as a combined variable for word length and orthographic neighbourhood size (N), for which neuroimaging results are still either scarce or inconsistent. Data were analysed using multiple linear regression analysis of event-related fMRI data acquired from 21 subjects in a silent reading paradigm. The frequency variable correlated negatively with activation in left fusiform gyrus, bilateral inferior frontal gyri and bilateral insulae, indicating that word frequency can affect multiple aspects of word processing. N correlated positively with brain activity in left and right middle temporal gyri as well as right inferior frontal gyrus. Thus, our analysis revealed multiple distinct brain areas involved in visual word processing within one data set.

Age-related decline of precision and binding in visual working memory.

PubMed

Peich, Muy-Cheng; Husain, Masud; Bays, Paul M

2013-09-01

Working memory declines with normal aging, but the nature of this impairment is debated. Studies based on detecting changes to arrays of visual objects have identified two possible components to age-related decline: a reduction in the number of items that can be stored, or a deficit in maintaining the associations (bindings) between individual object features. However, some investigations have reported intact binding with aging, and specific deficits arising only in Alzheimer's disease. Here, using a recently developed continuous measure of recall fidelity, we tested the precision with which adults of different ages could reproduce from memory the orientation and color of a probed array item. The results reveal a further component of cognitive decline: an age-related decrease in the resolution with which visual information can be maintained in working memory. This increase in recall variability with age was strongest under conditions of greater memory load. Moreover, analysis of the distribution of errors revealed that older participants were more likely to incorrectly report one of the unprobed items in memory, consistent with an age-related increase in misbinding. These results indicate a systematic decline with age in working memory resources that can be recruited to store visual information. The paradigm presented here provides a sensitive index of both memory resolution and feature binding, with the potential for assessing their modulation by interventions. The findings have implications for understanding the mechanisms underpinning working memory deficits in both health and disease.

Age-Related Decline of Precision and Binding in Visual Working Memory

PubMed Central

2013-01-01

Working memory declines with normal aging, but the nature of this impairment is debated. Studies based on detecting changes to arrays of visual objects have identified two possible components to age-related decline: a reduction in the number of items that can be stored, or a deficit in maintaining the associations (bindings) between individual object features. However, some investigations have reported intact binding with aging, and specific deficits arising only in Alzheimer’s disease. Here, using a recently developed continuous measure of recall fidelity, we tested the precision with which adults of different ages could reproduce from memory the orientation and color of a probed array item. The results reveal a further component of cognitive decline: an age-related decrease in the resolution with which visual information can be maintained in working memory. This increase in recall variability with age was strongest under conditions of greater memory load. Moreover, analysis of the distribution of errors revealed that older participants were more likely to incorrectly report one of the unprobed items in memory, consistent with an age-related increase in misbinding. These results indicate a systematic decline with age in working memory resources that can be recruited to store visual information. The paradigm presented here provides a sensitive index of both memory resolution and feature binding, with the potential for assessing their modulation by interventions. The findings have implications for understanding the mechanisms underpinning working memory deficits in both health and disease. PMID:23978008

Physical Features of Visual Images Affect Macaque Monkey’s Preference for These Images

PubMed Central

Funahashi, Shintaro

2016-01-01

Animals exhibit different degrees of preference toward various visual stimuli. In addition, it has been shown that strongly preferred stimuli can often act as a reward. The aim of the present study was to determine what features determine the strength of the preference for visual stimuli in order to examine neural mechanisms of preference judgment. We used 50 color photographs obtained from the Flickr Material Database (FMD) as original stimuli. Four macaque monkeys performed a simple choice task, in which two stimuli selected randomly from among the 50 stimuli were simultaneously presented on a monitor and monkeys were required to choose either stimulus by eye movements. We considered that the monkeys preferred the chosen stimulus if it continued to look at the stimulus for an additional 6 s and calculated a choice ratio for each stimulus. Each monkey exhibited a different choice ratio for each of the original 50 stimuli. They tended to select clear, colorful and in-focus stimuli. Complexity and clarity were stronger determinants of preference than colorfulness. Images that included greater amounts of spatial frequency components were selected more frequently. These results indicate that particular physical features of the stimulus can affect the strength of a monkey’s preference and that the complexity, clarity and colorfulness of the stimulus are important determinants of this preference. Neurophysiological studies would be needed to examine whether these features of visual stimuli produce more activation in neurons that participate in this preference judgment. PMID:27853424

BlockLogo: visualization of peptide and sequence motif conservation

PubMed Central

Olsen, Lars Rønn; Kudahl, Ulrich Johan; Simon, Christian; Sun, Jing; Schönbach, Christian; Reinherz, Ellis L.; Zhang, Guang Lan; Brusic, Vladimir

2013-01-01

BlockLogo is a web-server application for visualization of protein and nucleotide fragments, continuous protein sequence motifs, and discontinuous sequence motifs using calculation of block entropy from multiple sequence alignments. The user input consists of a multiple sequence alignment, selection of motif positions, type of sequence, and output format definition. The output has BlockLogo along with the sequence logo, and a table of motif frequencies. We deployed BlockLogo as an online application and have demonstrated its utility through examples that show visualization of T-cell epitopes and B-cell epitopes (both continuous and discontinuous). Our additional example shows a visualization and analysis of structural motifs that determine specificity of peptide binding to HLA-DR molecules. The BlockLogo server also employs selected experimentally validated prediction algorithms to enable on-the-fly prediction of MHC binding affinity to 15 common HLA class I and class II alleles as well as visual analysis of discontinuous epitopes from multiple sequence alignments. It enables the visualization and analysis of structural and functional motifs that are usually described as regular expressions. It provides a compact view of discontinuous motifs composed of distant positions within biological sequences. BlockLogo is available at: http://research4.dfci.harvard.edu/cvc/blocklogo/ and http://methilab.bu.edu/blocklogo/ PMID:24001880

Higher Level Visual Cortex Represents Retinotopic, Not Spatiotopic, Object Location

PubMed Central

Kanwisher, Nancy

2012-01-01

The crux of vision is to identify objects and determine their locations in the environment. Although initial visual representations are necessarily retinotopic (eye centered), interaction with the real world requires spatiotopic (absolute) location information. We asked whether higher level human visual cortex—important for stable object recognition and action—contains information about retinotopic and/or spatiotopic object position. Using functional magnetic resonance imaging multivariate pattern analysis techniques, we found information about both object category and object location in each of the ventral, dorsal, and early visual regions tested, replicating previous reports. By manipulating fixation position and stimulus position, we then tested whether these location representations were retinotopic or spatiotopic. Crucially, all location information was purely retinotopic. This pattern persisted when location information was irrelevant to the task, and even when spatiotopic (not retinotopic) stimulus position was explicitly emphasized. We also conducted a “searchlight” analysis across our entire scanned volume to explore additional cortex but again found predominantly retinotopic representations. The lack of explicit spatiotopic representations suggests that spatiotopic object position may instead be computed indirectly and continually reconstructed with each eye movement. Thus, despite our subjective impression that visual information is spatiotopic, even in higher level visual cortex, object location continues to be represented in retinotopic coordinates. PMID:22190434

Pigeons (C. livia) Follow Their Head during Turning Flight: Head Stabilization Underlies the Visual Control of Flight.

PubMed

Ros, Ivo G; Biewener, Andrew A

2017-01-01

Similar flight control principles operate across insect and vertebrate fliers. These principles indicate that robust solutions have evolved to meet complex behavioral challenges. Following from studies of visual and cervical feedback control of flight in insects, we investigate the role of head stabilization in providing feedback cues for controlling turning flight in pigeons. Based on previous observations that the eyes of pigeons remain at relatively fixed orientations within the head during flight, we test potential sensory control inputs derived from head and body movements during 90° aerial turns. We observe that periods of angular head stabilization alternate with rapid head repositioning movements (head saccades), and confirm that control of head motion is decoupled from aerodynamic and inertial forces acting on the bird's continuously rotating body during turning flapping flight. Visual cues inferred from head saccades correlate with changes in flight trajectory; whereas the magnitude of neck bending predicts angular changes in body position. The control of head motion to stabilize a pigeon's gaze may therefore facilitate extraction of important motion cues, in addition to offering mechanisms for controlling body and wing movements. Strong similarities between the sensory flight control of birds and insects may also inspire novel designs of robust controllers for human-engineered autonomous aerial vehicles.

Unconscious presentation of fearful face modulates electrophysiological responses to emotional prosody.

PubMed

Doi, Hirokazu; Shinohara, Kazuyuki

2015-03-01

Cross-modal integration of visual and auditory emotional cues is supposed to be advantageous in the accurate recognition of emotional signals. However, the neural locus of cross-modal integration between affective prosody and unconsciously presented facial expression in the neurologically intact population is still elusive at this point. The present study examined the influences of unconsciously presented facial expressions on the event-related potentials (ERPs) in emotional prosody recognition. In the experiment, fearful, happy, and neutral faces were presented without awareness by continuous flash suppression simultaneously with voices containing laughter and a fearful shout. The conventional peak analysis revealed that the ERPs were modulated interactively by emotional prosody and facial expression at multiple latency ranges, indicating that audio-visual integration of emotional signals takes place automatically without conscious awareness. In addition, the global field power during the late-latency range was larger for shout than for laughter only when a fearful face was presented unconsciously. The neural locus of this effect was localized to the left posterior fusiform gyrus, giving support to the view that the cortical region, traditionally considered to be unisensory region for visual processing, functions as the locus of audiovisual integration of emotional signals. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Pigeons (C. livia) Follow Their Head during Turning Flight: Head Stabilization Underlies the Visual Control of Flight

PubMed Central

Ros, Ivo G.; Biewener, Andrew A.

2017-01-01

Similar flight control principles operate across insect and vertebrate fliers. These principles indicate that robust solutions have evolved to meet complex behavioral challenges. Following from studies of visual and cervical feedback control of flight in insects, we investigate the role of head stabilization in providing feedback cues for controlling turning flight in pigeons. Based on previous observations that the eyes of pigeons remain at relatively fixed orientations within the head during flight, we test potential sensory control inputs derived from head and body movements during 90° aerial turns. We observe that periods of angular head stabilization alternate with rapid head repositioning movements (head saccades), and confirm that control of head motion is decoupled from aerodynamic and inertial forces acting on the bird's continuously rotating body during turning flapping flight. Visual cues inferred from head saccades correlate with changes in flight trajectory; whereas the magnitude of neck bending predicts angular changes in body position. The control of head motion to stabilize a pigeon's gaze may therefore facilitate extraction of important motion cues, in addition to offering mechanisms for controlling body and wing movements. Strong similarities between the sensory flight control of birds and insects may also inspire novel designs of robust controllers for human-engineered autonomous aerial vehicles. PMID:29249929

Semantic Interaction for Visual Analytics: Toward Coupling Cognition and Computation

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

Endert, Alexander

2014-07-01

The dissertation discussed in this article [1] was written in the midst of an era of digitization. The world is becoming increasingly instrumented with sensors, monitoring, and other methods for generating data describing social, physical, and natural phenomena. Thus, data exist with the potential of being analyzed to uncover, or discover, the phenomena from which it was created. However, as the analytic models leveraged to analyze these data continue to increase in complexity and computational capability, how can visualizations and user interaction methodologies adapt and evolve to continue to foster discovery and sensemaking?

Positive fEMG Patterns with Ambiguity in Paintings.

PubMed

Jakesch, Martina; Goller, Juergen; Leder, Helmut

2017-01-01

Whereas ambiguity in everyday life is often negatively evaluated, it is considered key in art appreciation. In a facial EMG study, we tested whether the positive role of visual ambiguity in paintings is reflected in a continuous affective evaluation on a subtle level. We presented ambiguous (disfluent) and non-ambiguous (fluent) versions of Magritte paintings and found that M. Zygomaticus major activation was higher and M. corrugator supercilii activation was lower for ambiguous than for non-ambiguous versions. Our findings reflect a positive continuous affective evaluation to visual ambiguity in paintings over the 5 s presentation time. We claim that this finding is indirect evidence for the hypothesis that visual stimuli classified as art, evoke a safe state for indulging into experiencing ambiguity, challenging the notion that processing fluency is generally related to positive affect.

Analysis, simulation and visualization of 1D tapping via reduced dynamical models

NASA Astrophysics Data System (ADS)

Blackmore, Denis; Rosato, Anthony; Tricoche, Xavier; Urban, Kevin; Zou, Luo

2014-04-01

A low-dimensional center-of-mass dynamical model is devised as a simplified means of approximately predicting some important aspects of the motion of a vertical column comprised of a large number of particles subjected to gravity and periodic vertical tapping. This model is investigated first as a continuous dynamical system using analytical, simulation and visualization techniques. Then, by employing an approach analogous to that used to approximate the dynamics of a bouncing ball on an oscillating flat plate, it is modeled as a discrete dynamical system and analyzed to determine bifurcations and transitions to chaotic motion along with other properties. The predictions of the analysis are then compared-primarily qualitatively-with visualization and simulation results of the reduced continuous model, and ultimately with simulations of the complete system dynamics.

47 CFR 73.682 - TV transmission standards.

Code of Federal Regulations, 2012 CFR

2012-10-01

....682 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO... frequency shall be nominally 1.25 MHz above the lower boundary of the channel. (3) The aural center frequency shall be 4.5 MHz higher than the visual carrier frequency. (4) The visual transmission amplitude...

47 CFR 73.682 - TV transmission standards.

Code of Federal Regulations, 2011 CFR

2011-10-01

....682 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO... frequency shall be nominally 1.25 MHz above the lower boundary of the channel. (3) The aural center frequency shall be 4.5 MHz higher than the visual carrier frequency. (4) The visual transmission amplitude...

47 CFR 73.682 - TV transmission standards.

Code of Federal Regulations, 2013 CFR

2013-10-01

....682 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO... frequency shall be nominally 1.25 MHz above the lower boundary of the channel. (3) The aural center frequency shall be 4.5 MHz higher than the visual carrier frequency. (4) The visual transmission amplitude...

47 CFR 73.682 - TV transmission standards.

Code of Federal Regulations, 2014 CFR

2014-10-01

....682 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO... frequency shall be nominally 1.25 MHz above the lower boundary of the channel. (3) The aural center frequency shall be 4.5 MHz higher than the visual carrier frequency. (4) The visual transmission amplitude...

47 CFR 73.682 - TV transmission standards.

Code of Federal Regulations, 2010 CFR

2010-10-01

....682 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO... frequency shall be nominally 1.25 MHz above the lower boundary of the channel. (3) The aural center frequency shall be 4.5 MHz higher than the visual carrier frequency. (4) The visual transmission amplitude...

On the use of continuous flash suppression for the study of visual processing outside of awareness

PubMed Central

Yang, Eunice; Brascamp, Jan; Kang, Min-Suk; Blake, Randolph

2014-01-01

The interocular suppression technique termed continuous flash suppression (CFS) has become an immensely popular tool for investigating visual processing outside of awareness. The emerging picture from studies using CFS is that extensive processing of a visual stimulus, including its semantic and affective content, occurs despite suppression from awareness of that stimulus by CFS. However, the current implementation of CFS in many studies examining processing outside of awareness has several drawbacks that may be improved upon for future studies using CFS. In this paper, we address some of those shortcomings, particularly ones that affect the assessment of unawareness during CFS, and ones to do with the use of “visible” conditions that are often included as a comparison to a CFS condition. We also discuss potential biases in stimulus processing as a result of spatial attention and feature-selective suppression. We suggest practical guidelines that minimize the effects of those limitations in using CFS to study visual processing outside of awareness. PMID:25071685

Visual objects and universal meanings: AIDS posters and the politics of globalisation and history.

PubMed

Stein, Claudia; Cooter, Roger

2011-01-01

Drawing on recent visual and spatial turns in history writing, this paper considers AIDS posters from the perspective of their museum 'afterlife' as collected material objects. Museum spaces serve changing political and epistemological projects, and the visual objects they house are not immune from them. A recent globally themed exhibition of AIDS posters at an arts and crafts museum in Hamburg is cited in illustration. The exhibition also serves to draw attention to institutional continuities in collecting agendas. Revealed, contrary to postmodernist expectations, is how today's application of aesthetic display for the purpose of making 'global connections' does not radically break with the virtues and morals attached to the visual at the end of the nineteenth century. The historicisation of such objects needs to take into account this complicated mix of change and continuity in aesthetic concepts and political inscriptions. Otherwise, historians fall prey to seductive aesthetics without being aware of the politics of them. This article submits that aesthetics is politics.

Visual Objects and Universal Meanings: AIDS Posters and the Politics of Globalisation and History

PubMed Central

STEIN, CLAUDIA; COOTER, ROGER

2011-01-01

Drawing on recent visual and spatial turns in history writing, this paper considers AIDS posters from the perspective of their museum ‘afterlife’ as collected material objects. Museum spaces serve changing political and epistemological projects, and the visual objects they house are not immune from them. A recent globally themed exhibition of AIDS posters at an arts and crafts museum in Hamburg is cited in illustration. The exhibition also serves to draw attention to institutional continuities in collecting agendas. Revealed, contrary to postmodernist expectations, is how today’s application of aesthetic display for the purpose of making ‘global connections’ does not radically break with the virtues and morals attached to the visual at the end of the nineteenth century. The historicisation of such objects needs to take into account this complicated mix of change and continuity in aesthetic concepts and political inscriptions. Otherwise, historians fall prey to seductive aesthetics without being aware of the politics of them. This article submits that aesthetics is politics. PMID:23752866

Multimedia Analysis plus Visual Analytics = Multimedia Analytics

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

Chinchor, Nancy; Thomas, James J.; Wong, Pak C.

2010-10-01

Multimedia analysis has focused on images, video, and to some extent audio and has made progress in single channels excluding text. Visual analytics has focused on the user interaction with data during the analytic process plus the fundamental mathematics and has continued to treat text as did its precursor, information visualization. The general problem we address in this tutorial is the combining of multimedia analysis and visual analytics to deal with multimedia information gathered from different sources, with different goals or objectives, and containing all media types and combinations in common usage.

Effect of visible light treatments on postharvest senescence of broccoli (Brassica oleracea L.).

PubMed

Büchert, Agustin M; Gómez Lobato, Maria E; Villarreal, Natalia M; Civello, Pedro M; Martínez, Gustavo A

2011-01-30

Broccoli (Brassica oleracea L.) is a rapidly perishable vegetable crop. Several postharvest treatments have been applied in order to delay de-greening. Since light has been shown to have an effect on pigment accumulation during development and darkness is known to induce senescence, the effect of continuous and periodic exposure to low-intensity white light at 22 °C on postharvest senescence of broccoli heads was assayed. Exposure to a constant dose of 12 micromol m(-2) s(-1) was selected as the most suitable treatment and was employed for subsequent experiments. During the course of the treatments, hue and L* values as well as chlorophyll content and visual observation of florets indicated an evident delay in yellowing in treated samples compared with controls. No statistically significant differences in total protein content were found, but soluble protein content was higher in treated samples. Total and reducing sugar as well as starch levels decreased during postharvest senescence, with lower values in control samples. The results of this study indicate that storage under continuous low-intensity light is an efficient and low-cost treatment that delays postharvest senescence while maintaining the quality of harvested broccoli florets. 2010 Society of Chemical Industry.

The Tactile Continuity Illusion

ERIC Educational Resources Information Center

Kitagawa, Norimichi; Igarashi, Yuka; Kashino, Makio

2009-01-01

We can perceive the continuity of an object or event by integrating spatially/temporally discrete sensory inputs. The mechanism underlying this perception of continuity has intrigued many researchers and has been well documented in both the visual and auditory modalities. The present study shows for the first time to our knowledge that an illusion…

Precursors of developmental dyslexia: an overview of the longitudinal Dutch Dyslexia Programme study.

PubMed

van der Leij, Aryan; van Bergen, Elsje; van Zuijen, Titia; de Jong, Peter; Maurits, Natasha; Maassen, Ben

2013-11-01

Converging evidence suggests that developmental dyslexia is a neurobiological disorder, characterized by deficits in the auditory, visual, and linguistic domains. In the longitudinal project of the Dutch Dyslexia Programme, 180 children with a familial risk of dyslexia (FR) and a comparison group of 120 children without FR (noFR) were followed from the age of 2 months up to 9 years. Children were assessed on (1) auditory, speech, and visual event-related potentials every half year between 2 and 41 months; (2) expressive and receptive language, motor development, behaviour problems, and home-literacy environment by questionnaires at the age of 2 and 3; (3) speech-language and cognitive development from 47 months onwards; and (4) preliteracy and subskills of reading, and reading development during kindergarten and Grades 2 and 3. With regard to precursors of reading disability, first analyses showed specific differences between FR and noFR children in neurophysiological, cognitive, and early language measures. Once reading tests administered from age 7 to 9 years were available, the children were divided into three groups: FR children with and without dyslexia, and controls. Analyses of the differences between reading groups yielded distinct profiles and developmental trajectories. On early speech and visual processing, and several cognitive measures, performance of the non-dyslexic FR group differed from the dyslexic FR group and controls, indicating continuity of the influence of familial risk. Parental reading and rapid naming skills appeared to indicate their offspring's degree of familial risk. Furthermore, on rapid naming and nonverbal IQ, the non-dyslexic FR group performed similarly to the controls, suggesting protective factors. There are indications of differences between the FR and control groups, irrespective of reading outcome. These results contribute to the distinction between the deficits correlated to dyslexia as a manifest reading disorder and deficits correlated to familial risk only. Copyright © 2013 John Wiley & Sons, Ltd.

Imprinting modulates processing of visual information in the visual wulst of chicks.

PubMed

Maekawa, Fumihiko; Komine, Okiru; Sato, Katsushige; Kanamatsu, Tomoyuki; Uchimura, Motoaki; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

2006-11-14

Imprinting behavior is one form of learning and memory in precocial birds. With the aim of elucidating of the neural basis for visual imprinting, we focused on visual information processing. A lesion in the visual wulst, which is similar functionally to the mammalian visual cortex, caused anterograde amnesia in visual imprinting behavior. Since the color of an object was one of the important cues for imprinting, we investigated color information processing in the visual wulst. Intrinsic optical signals from the visual wulst were detected in the early posthatch period and the peak regions of responses to red, green, and blue were spatially organized from the caudal to the nasal regions in dark-reared chicks. This spatial representation of color recognition showed plastic changes, and the response pattern along the antero-posterior axis of the visual wulst altered according to the color the chick was imprinted to. These results indicate that the thalamofugal pathway is critical for learning the imprinting stimulus and that the visual wulst shows learning-related plasticity and may relay processed visual information to indicate the color of the imprint stimulus to the memory storage region, e.g., the intermediate medial mesopallium.

Imprinting modulates processing of visual information in the visual wulst of chicks

PubMed Central

Maekawa, Fumihiko; Komine, Okiru; Sato, Katsushige; Kanamatsu, Tomoyuki; Uchimura, Motoaki; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

2006-01-01

Background Imprinting behavior is one form of learning and memory in precocial birds. With the aim of elucidating of the neural basis for visual imprinting, we focused on visual information processing. Results A lesion in the visual wulst, which is similar functionally to the mammalian visual cortex, caused anterograde amnesia in visual imprinting behavior. Since the color of an object was one of the important cues for imprinting, we investigated color information processing in the visual wulst. Intrinsic optical signals from the visual wulst were detected in the early posthatch period and the peak regions of responses to red, green, and blue were spatially organized from the caudal to the nasal regions in dark-reared chicks. This spatial representation of color recognition showed plastic changes, and the response pattern along the antero-posterior axis of the visual wulst altered according to the color the chick was imprinted to. Conclusion These results indicate that the thalamofugal pathway is critical for learning the imprinting stimulus and that the visual wulst shows learning-related plasticity and may relay processed visual information to indicate the color of the imprint stimulus to the memory storage region, e.g., the intermediate medial mesopallium. PMID:17101060

Laser Optometric Assessment Of Visual Display Viewability

NASA Astrophysics Data System (ADS)

Murch, Gerald M.

1983-08-01

Through the technique of laser optometry, measurements of a display user's visual accommodation and binocular convergence were used to assess the visual impact of display color, technology, contrast, and work time. The studies reported here indicate the potential of visual-function measurements as an objective means of improving the design of visual displays.

Visual and psychological stress during computer work in healthy, young females-physiological responses.

PubMed

Mork, Randi; Falkenberg, Helle K; Fostervold, Knut Inge; Thorud, Hanne Mari S

2018-05-30

Among computer workers, visual complaints, and neck pain are highly prevalent. This study explores how occupational simulated stressors during computer work, like glare and psychosocial stress, affect physiological responses in young females with normal vision. The study was a within-subject laboratory experiment with a counterbalanced, repeated design. Forty-three females performed four 10-min computer-work sessions with different stress exposures: (1) minimal stress; (2) visual stress (direct glare); (3) psychological stress; and (4) combined visual and psychological stress. Muscle activity and muscle blood flow in trapezius, muscle blood flow in orbicularis oculi, heart rate, blood pressure, blink rate and postural angles were continuously recorded. Immediately after each computer-work session, fixation disparity was measured and a questionnaire regarding perceived workstation lighting and stress was completed. Exposure to direct glare resulted in increased trapezius muscle blood flow, increased blink rate, and forward bending of the head. Psychological stress induced a transient increase in trapezius muscle activity and a more forward-bent posture. Bending forward towards the computer screen was correlated with higher productivity (reading speed), indicating a concentration or stress response. Forward bent posture was also associated with changes in fixation disparity. Furthermore, during computer work per se, trapezius muscle activity and blood flow, orbicularis oculi muscle blood flow, and heart rate were increased compared to rest. Exposure to glare and psychological stress during computer work were shown to influence the trapezius muscle, posture, and blink rate in young, healthy females with normal binocular vision, but in different ways. Accordingly, both visual and psychological factors must be taken into account when optimizing computer workstations to reduce physiological responses that may cause excessive eyestrain and musculoskeletal load.

The force pyramid: a spatial analysis of force application during virtual reality brain tumor resection.

PubMed

Azarnoush, Hamed; Siar, Samaneh; Sawaya, Robin; Zhrani, Gmaan Al; Winkler-Schwartz, Alexander; Alotaibi, Fahad Eid; Bugdadi, Abdulgadir; Bajunaid, Khalid; Marwa, Ibrahim; Sabbagh, Abdulrahman Jafar; Del Maestro, Rolando F

2017-07-01

OBJECTIVE Virtual reality simulators allow development of novel methods to analyze neurosurgical performance. The concept of a force pyramid is introduced as a Tier 3 metric with the ability to provide visual and spatial analysis of 3D force application by any instrument used during simulated tumor resection. This study was designed to answer 3 questions: 1) Do study groups have distinct force pyramids? 2) Do handedness and ergonomics influence force pyramid structure? 3) Are force pyramids dependent on the visual and haptic characteristics of simulated tumors? METHODS Using a virtual reality simulator, NeuroVR (formerly NeuroTouch), ultrasonic aspirator force application was continually assessed during resection of simulated brain tumors by neurosurgeons, residents, and medical students. The participants performed simulated resections of 18 simulated brain tumors with different visual and haptic characteristics. The raw data, namely, coordinates of the instrument tip as well as contact force values, were collected by the simulator. To provide a visual and qualitative spatial analysis of forces, the authors created a graph, called a force pyramid, representing force sum along the z-coordinate for different xy coordinates of the tool tip. RESULTS Sixteen neurosurgeons, 15 residents, and 84 medical students participated in the study. Neurosurgeon, resident and medical student groups displayed easily distinguishable 3D "force pyramid fingerprints." Neurosurgeons had the lowest force pyramids, indicating application of the lowest forces, followed by resident and medical student groups. Handedness, ergonomics, and visual and haptic tumor characteristics resulted in distinct well-defined 3D force pyramid patterns. CONCLUSIONS Force pyramid fingerprints provide 3D spatial assessment displays of instrument force application during simulated tumor resection. Neurosurgeon force utilization and ergonomic data form a basis for understanding and modulating resident force application and improving patient safety during tumor resection.

Stimulation-induced decreases in the diffusion of extra-vascular water in the human visual cortex: a window in time and space on mechanisms of brain water transport and economy.

PubMed

Baslow, Morris H; Hu, Caixia; Guilfoyle, David N

2012-07-01

In a human magnetic resonance diffusion-weighted imaging (DWI) investigation at 3 T and high diffusion sensitivity weighting (b = 1,800 s/mm(2)), which emphasizes the contribution of water in the extra-vascular compartment and minimizes that of the vascular compartment, we observed that visual stimulation with a flashing checkerboard at 8 Hz for a period of 600 s in eight subjects resulted in significant increases in DWI signals (mean +2.70%, range +0.51 to 8.54%). The increases in DWI signals in activated areas of the visual cortex indicated that during stimulation, the apparent diffusion coefficient (ADC) of extra-vascular compartment water decreased. In response to continuous stimulation, DWI signals gradually increased from pre-stimulation controls, leveling off after 400-500 s. During recovery from stimulation, DWI signals gradually decreased, approaching control levels in 300-400 s. In this study, we show for the first time that the effects of visual stimulation on DWI signals in the human visual cortex are cumulative over an extended period of time. We propose that these relatively slow stimulation-induced changes in the ADC of water in the extra-vascular compartment are due to transient changes in the ratio of faster diffusing free water to slower diffusing bound water and reflect brain water transport processes between the vascular and extra-vascular compartments at the cellular level. The nature of these processes including possible roles of the putative glucose water import and N-acetylaspartate water export molecular water pumps in brain function are discussed.

Online kinematic regulation by visual feedback for grasp versus transport during reach-to-pinch

PubMed Central

Nataraj, Raviraj; Pasluosta, Cristian; Li, Zong-Ming

2014-01-01

Purpose This study investigated novel kinematic performance parameters to understand regulation by visual feedback (VF) of the reaching hand on the grasp and transport components during the reach-to-pinch maneuver. Conventional metrics often signify discrete movement features to postulate sensory-based control effects (e.g., time for maximum velocity to signify feedback delay). The presented metrics of this study were devised to characterize relative vision-based control of the sub-movements across the entire maneuver. Methods Movement performance was assessed according to reduced variability and increased efficiency of kinematic trajectories. Variability was calculated as the standard deviation about the observed mean trajectory for a given subject and VF condition across kinematic derivatives for sub-movements of inter-pad grasp (distance between thumb and index finger-pads; relative orientation of finger-pads) and transport (distance traversed by wrist). A Markov analysis then examined the probabilistic effect of VF on which movement component exhibited higher variability over phases of the complete maneuver. Jerk-based metrics of smoothness (minimal jerk) and energy (integrated jerk-squared) were applied to indicate total movement efficiency with VF. Results/Discussion The reductions in grasp variability metrics with VF were significantly greater (p<0.05) compared to transport for velocity, acceleration, and jerk, suggesting separate control pathways for each component. The Markov analysis indicated that VF preferentially regulates grasp over transport when continuous control is modeled probabilistically during the movement. Efficiency measures demonstrated VF to be more integral for early motor planning of grasp than transport in producing greater increases in smoothness and trajectory adjustments (i.e., jerk-energy) early compared to late in the movement cycle. Conclusions These findings demonstrate the greater regulation by VF on kinematic performance of grasp compared to transport and how particular features of this relativistic control occur continually over the maneuver. Utilizing the advanced performance metrics presented in this study facilitated characterization of VF effects continuously across the entire movement in corroborating the notion of separate control pathways for each component. PMID:24968371

[Infobarris: an interactive tool to monitor and disseminate information on health and its determinants in the neighbourhoods of Barcelona (Spain)].

PubMed

Llimona, Pere; Pérez, Glòria; Rodríguez-Sanz, Maica; Novoa, Ana M; Espelt, Albert; García de Olalla, Patricia; Borrell, Carme

In order to know about the health of the population, it is necessary to perform a systematic and continuous analysis of their health status and social and economic health determinants. The objective of this paper is to describe the development and implementation of the Infobarris tool, which allows to visualize a wide battery of indicators and social determinants of health by neighbourhoods in the city of Barcelona (Spain). For the development of the Infobarris tool, we used an agile methodology that allows the development of a project in iterative and incremental stages, which are the following: selection of indicators, design of the prototype, development of the tool, data loading, and tool review and improvements. Infobarris displays 64 indicators of health and its determinants through graphics, maps and tables, in a friendly, interactive and attractive way, which facilitates health surveillance in the neighbourhoods of Barcelona. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Wetting in Color: Designing a colorometric indicator for wettability

NASA Astrophysics Data System (ADS)

Raymond, Kevin; Burgess, Ian B.; Koay, Natalie; Kolle, Mathias; Loncar, Marko; Aizenberg, Joanna

2012-02-01

Colorimetric litmus tests such as pH paper have enjoyed wide commercial success due to their inexpensive production and exceptional ease of use. While such indicators commonly rely on a specific photochemical response to an analyte, we exploit structural color, derived from coherent scattering from wavelength-scale porosity rather than molecular absorption or luminescence, to create a Wetting-in-Color-Kit (WICK). This inexpensive and highly selective colorimetric indicator for organic liquids employs chemically encoded inverse-opal photonic crystals to translate minute differences in liquids' wettability to macroscopically distinct, easy-to-visualize color patterns. The highly symmetric re-entrant inter-pore geometry imparts a highly specific wetting threshold for liquids. We developed surface modification techniques to generate built-in chemistry gradients within the porous network. These let us tailor the wettability threshold to specific liquids across a continuous range. As wetting is a generic fluidic phenomenon, we envision that WICK could be suitable for applications in authentication or identification of unknown liquids across a broad range of industries.

Survey of cockpit visual problems of senior pilots.

DOT National Transportation Integrated Search

1977-01-01

Fifty general aviation pilots (average age 49; range 40-73) completed a questionnaire concerning cockpit visual problems. The results of the questionnaire indicated that proper interpretation of the airspeed indicator and the altimeter required the b...

47 CFR 73.1540 - Carrier frequency measurements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 73.1540 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES... measurements. (a) The carrier frequency of each AM and FM station and the visual carrier frequency and the difference between the visual carrier and the aural carrier or center frequency of each TV and Class A TV...

Multiple Transient Signals in Human Visual Cortex Associated with an Elementary Decision

PubMed Central

Nolte, Guido

2017-01-01

The cerebral cortex continuously undergoes changes in its state, which are manifested in transient modulations of the cortical power spectrum. Cortical state changes also occur at full wakefulness and during rapid cognitive acts, such as perceptual decisions. Previous studies found a global modulation of beta-band (12–30 Hz) activity in human and monkey visual cortex during an elementary visual decision: reporting the appearance or disappearance of salient visual targets surrounded by a distractor. The previous studies disentangled neither the motor action associated with behavioral report nor other secondary processes, such as arousal, from perceptual decision processing per se. Here, we used magnetoencephalography in humans to pinpoint the factors underlying the beta-band modulation. We found that disappearances of a salient target were associated with beta-band suppression, and target reappearances with beta-band enhancement. This was true for both overt behavioral reports (immediate button presses) and silent counting of the perceptual events. This finding indicates that the beta-band modulation was unrelated to the execution of the motor act associated with a behavioral report of the perceptual decision. Further, changes in pupil-linked arousal, fixational eye movements, or gamma-band responses were not necessary for the beta-band modulation. Together, our results suggest that the beta-band modulation was a top-down signal associated with the process of converting graded perceptual signals into a categorical format underlying flexible behavior. This signal may have been fed back from brain regions involved in decision processing to visual cortex, thus enforcing a “decision-consistent” cortical state. SIGNIFICANCE STATEMENT Elementary visual decisions are associated with a rapid state change in visual cortex, indexed by a modulation of neural activity in the beta-frequency range. Such decisions are also followed by other events that might affect the state of visual cortex, including the motor command associated with the report of the decision, an increase in pupil-linked arousal, fixational eye movements, and fluctuations in bottom-up sensory processing. Here, we ruled out the necessity of these events for the beta-band modulation of visual cortex. We propose that the modulation reflects a decision-related state change, which is induced by the conversion of graded perceptual signals into a categorical format underlying behavior. The resulting decision signal may be fed back to visual cortex. PMID:28495972

Perception of biological motion from size-invariant body representations.

PubMed

Lappe, Markus; Wittinghofer, Karin; de Lussanet, Marc H E

2015-01-01

The visual recognition of action is one of the socially most important and computationally demanding capacities of the human visual system. It combines visual shape recognition with complex non-rigid motion perception. Action presented as a point-light animation is a striking visual experience for anyone who sees it for the first time. Information about the shape and posture of the human body is sparse in point-light animations, but it is essential for action recognition. In the posturo-temporal filter model of biological motion perception posture information is picked up by visual neurons tuned to the form of the human body before body motion is calculated. We tested whether point-light stimuli are processed through posture recognition of the human body form by using a typical feature of form recognition, namely size invariance. We constructed a point-light stimulus that can only be perceived through a size-invariant mechanism. This stimulus changes rapidly in size from one image to the next. It thus disrupts continuity of early visuo-spatial properties but maintains continuity of the body posture representation. Despite this massive manipulation at the visuo-spatial level, size-changing point-light figures are spontaneously recognized by naive observers, and support discrimination of human body motion.

Breaking Continuous Flash Suppression: A New Measure of Unconscious Processing during Interocular Suppression?

PubMed Central

Stein, Timo; Hebart, Martin N.; Sterzer, Philipp

2011-01-01

Until recently, it has been thought that under interocular suppression high-level visual processing is strongly inhibited if not abolished. With the development of continuous flash suppression (CFS), a variant of binocular rivalry, this notion has now been challenged by a number of reports showing that even high-level aspects of visual stimuli, such as familiarity, affect the time stimuli need to overcome CFS and emerge into awareness. In this “breaking continuous flash suppression” (b-CFS) paradigm, differential unconscious processing during suppression is inferred when (a) speeded detection responses to initially invisible stimuli differ, and (b) no comparable differences are found in non-rivalrous control conditions supposed to measure non-specific threshold differences between stimuli. The aim of the present study was to critically evaluate these assumptions. In six experiments we compared the detection of upright and inverted faces. We found that not only under CFS, but also in control conditions upright faces were detected faster and more accurately than inverted faces, although the effect was larger during CFS. However, reaction time (RT) distributions indicated critical differences between the CFS and the control condition. When RT distributions were matched, similar effect sizes were obtained in both conditions. Moreover, subjective ratings revealed that CFS and control conditions are not perceptually comparable. These findings cast doubt on the usefulness of non-rivalrous control conditions to rule out non-specific threshold differences as a cause of shorter detection latencies during CFS. Thus, at least in its present form, the b-CFS paradigm cannot provide unequivocal evidence for unconscious processing under interocular suppression. Nevertheless, our findings also demonstrate that the b-CFS paradigm can be fruitfully applied as a highly sensitive device to probe differences between stimuli in their potency to gain access to awareness. PMID:22194718

Continuous full-time occlusion of the sound eye vs full-time occlusion of the sound eye periodically alternating with occlusion of the amblyopic eye in treatment of amblyopia: a prospective randomized study.

PubMed

Stanković, B; Milenković, S

2007-01-01

To compare continuous full-time (24 hours per day) occlusion of the sound eye with full-time occlusion (24 hours per day) of the sound eye 1 day more than the years of age periodically alternating with occlusion of the amblyopic eye for 1 day, as treatments for profound strabismic amblyopia in children older than 5 years. A total of 53 patients with visual acuity (VA) of 0.4 and less in the amblyopic eye (tested by crowded Landolt Cs) after previously being provided optimal optical correction were randomly assigned to receive either of the two patching regimens. VA and pattern reversal visual evoked potentials (PVEP) were recorded prospectively at 1-month intervals. Improvement in VA and the reduction in crowding difficulties (CD) were the main outcome measures of the treatment efficiency. Both treatment modalities were equally effective. Of the 51 subjects who completed the study, 21 (41.2%) were cured whereas 32 (62.7%) attained satisfactory improvement. Recovery of VA was related to age, with cure being obtained in 23.5% (4/17) and satisfactory improvement in 52.9% (9/17) of patients older than 9 years. Larger gain in VA influenced the stability of the vision over time. It can be concluded that in clinically monitored parameters both treatment modalities were equally effective without any statistical or clinical significance in the observed groups of patients. However, events like the "trade-off" effect, occurrence of occlusion amblyopia, or prolongation of PVEP latency of the sound eye indicate that full-time continuous occlusion possibly presents a more effective form of treatment.

Visual guidance of mobile platforms

NASA Astrophysics Data System (ADS)

Blissett, Rodney J.

1993-12-01

Two systems are described and results presented demonstrating aspects of real-time visual guidance of autonomous mobile platforms. The first approach incorporates prior knowledge in the form of rigid geometrical models linking visual references within the environment. The second approach is based on a continuous synthesis of information extracted from image tokens to generate a coarse-grained world model, from which potential obstacles are inferred. The use of these techniques in workplace applications is discussed.

An Architectural Model of Visual Motion Understanding

DTIC Science & Technology

1989-08-01

of the Center for Visual Sciences of the University of Rochester. Their courage in the face of the overwhelming com- plexity of the human visual...analysis should perform better than either approach by itself. Notice that the problems of the two approaches are non-overlapping. Continuous methods face no...success. This is not terribly surprising, as the problem is inherently very difficult. Consider the problems faced by a unit that is trying to compute the

PIGMENTS OF THE RETINA

PubMed Central

Wald, George

1936-01-01

1. Visual purple from the sea robin, sea bass, and scup is almost identical spectroscopically with that from frogs. The interrelations of this pigment with vitamin A and retinene are also the same as in the frog. 2. In strong acids or at pH > 11, the visual yellow of sea robin retinas is converted irreversibly into a pH indicator, yellow in acid and almost colorless in alkaline solution. Unlike neutral visual yellow, the indicator is not removed to form either vitamin A or visual purple. In the ammoniacal retina the reversion of visual yellow itself to purple is accelerated. 3. The combined pigment epithelium and choroid layer in these fishes contain vitamin A, flavine, and an unidentified xanthophyll. PMID:19872983

Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

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

Lin Mingde; Marshall, Craig T.; Qi, Yi

Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, aremore » invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 {mu}m{sup 2}). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0{+-}5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCO{sub DSA}=CO{sub Fick}. Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.« less

Thermodynamics of Meissner effect and flux pinning behavior in the bulk of single-crystal La 2 - x Sr x CuO 4 ( x = 0.09 )

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

Dhiman, I.; Ziesche, R.; Anand, V. K.

We have studied the magnetic flux pinning behavior and Meissner effect for the high-more » $$T_{\\rm c}$$ single crystal La$$_{2-x}$$Sr$$_{x}$$CuO$$_{4}$$ ($x$ = 0.09) superconductor using the polarized neutron imaging method with varying magnetic field and temperature. In the Meissner state expulsion of magnetic field (switched on during the measurements) is visualized, and the signatures of mixed state with increasing temperature are observed. While, for flux pinning behavior between 5 K $$\\leq$$ $T$ $$\\leq$$ 15 K and $$H_{\\rm ext}$$ = 63.5 mT (switched off during the measurements), the evolution of fringe pattern for both 0$$^{o}$$ and 90$$^{o}$$ sample orientation indicates magnetic flux pinning inside the bulk of the sample. At 25 K $$\\leq$$ $T$ $$\\leq$$ 32 K, a continuous decrease of inhomogeneously distribution pinned magnetic flux is observed, with the sample reaching a normal conducting state at $$T_{\\rm c}$$ ($$\\approx$$ 32 K). The flux pinning behavior is also explored as a function of $$H_{\\rm ext}$$, at $T$ = 5 K. As expected, with increasing $$H_{\\rm ext}$$ an increase in fringe density is observed, indicating an increase in magnetic flux pinning in the bulk of the sample. Therefore, in the present work for the first time we report bulk visualization of Meissner effect and flux pinning behavior in high-$$T_{\\rm c}$$ La$$_{2-x}$$Sr$$_{x}$$CuO$$_{4}$$ ($x$ = 0.09) superconductor. This study clearly demonstrates the potential of real space polarized neutron imaging technique for the visualization of the superconducting mixed state, particularly in the field of high-$$T_{\\rm c}$$ superconductors.« less

Emotional words facilitate lexical but not early visual processing.

PubMed

Trauer, Sophie M; Kotz, Sonja A; Müller, Matthias M

2015-12-12

Emotional scenes and faces have shown to capture and bind visual resources at early sensory processing stages, i.e. in early visual cortex. However, emotional words have led to mixed results. In the current study ERPs were assessed simultaneously with steady-state visual evoked potentials (SSVEPs) to measure attention effects on early visual activity in emotional word processing. Neutral and negative words were flickered at 12.14 Hz whilst participants performed a Lexical Decision Task. Emotional word content did not modulate the 12.14 Hz SSVEP amplitude, neither did word lexicality. However, emotional words affected the ERP. Negative compared to neutral words as well as words compared to pseudowords lead to enhanced deflections in the P2 time range indicative of lexico-semantic access. The N400 was reduced for negative compared to neutral words and enhanced for pseudowords compared to words indicating facilitated semantic processing of emotional words. LPC amplitudes reflected word lexicality and thus the task-relevant response. In line with previous ERP and imaging evidence, the present results indicate that written emotional words are facilitated in processing only subsequent to visual analysis.

Medical review licensing outcomes in drivers with visual field loss in Victoria, Australia

PubMed Central

Muir, Carlyn; Charlton, Judith L; Odell, Morris; Keeffe, Jill; Wood, Joanne; Bohensky, Megan; Fildes, Brian; Oxley, Jennifer; Bentley, Sharon; Rizzo, Matthew

2017-01-01

Background Good vision is essential for safe driving and studies have associated visual impairment with an increased crash risk. Currently, there is little information about the medical review of drivers with visual field loss. This study examines the prevalence of visual field loss among drivers referred for medical review in one Australian jurisdiction and investigates factors associated with licence outcome in this group. Methods A random sample of 10,000 (31.25 per cent) medical review cases was extracted for analysis from the Victorian licensing authority. Files were screened for the presence of six visual field-related medical conditions. Data were captured on a range of variables, including referral source, age, gender, health status, crash history and licence outcome. Prevalence analyses were univariate and descriptive. Logistic regression was used to assess factors associated with licence outcomes in the visual field loss group. Results Approximately 1.9 per cent of the 10,000 medical review cases screened had a visual field loss condition identified (n=194). Among the visual field loss group, 57.2 per cent were permitted to continue driving (conditional/unconditional licence). Primary referral sources were the police, self-referrals and general medical practitioners. Key factors associated with licence test outcomes were visual field condition, age group, crash involvement and referral to the Driver Licensing Authority’s Medical Advisors. Those who were younger had a crash involvement triggering referral and those who were referred to the Medical Advisors were more likely to have a positive licensing outcome. Conclusion The evidence base for making licensing decisions is complicated by the variable causes, patterns, progressions and measuring technologies for visual field loss. This study highlighted that the involvement of an expert medical advisory service in Victoria resulted in an increased likelihood that drivers with visual field loss will be allowed to continue driving. Further research is warranted to explore issues relating to severity of field loss and the capacity for compensation. PMID:27530283

Cross-modal cueing of attention alters appearance and early cortical processing of visual stimuli

PubMed Central

Störmer, Viola S.; McDonald, John J.; Hillyard, Steven A.

2009-01-01

The question of whether attention makes sensory impressions appear more intense has been a matter of debate for over a century. Recent psychophysical studies have reported that attention increases apparent contrast of visual stimuli, but the issue continues to be debated. We obtained converging neurophysiological evidence from human observers as they judged the relative contrast of visual stimuli presented to the left and right visual fields following a lateralized auditory cue. Cross-modal cueing of attention boosted the apparent contrast of the visual target in association with an enlarged neural response in the contralateral visual cortex that began within 100 ms after target onset. The magnitude of the enhanced neural response was positively correlated with perceptual reports of the cued target being higher in contrast. The results suggest that attention increases the perceived contrast of visual stimuli by boosting early sensory processing in the visual cortex. PMID:20007778

Cross-modal cueing of attention alters appearance and early cortical processing of visual stimuli.

PubMed

Störmer, Viola S; McDonald, John J; Hillyard, Steven A

2009-12-29

The question of whether attention makes sensory impressions appear more intense has been a matter of debate for over a century. Recent psychophysical studies have reported that attention increases apparent contrast of visual stimuli, but the issue continues to be debated. We obtained converging neurophysiological evidence from human observers as they judged the relative contrast of visual stimuli presented to the left and right visual fields following a lateralized auditory cue. Cross-modal cueing of attention boosted the apparent contrast of the visual target in association with an enlarged neural response in the contralateral visual cortex that began within 100 ms after target onset. The magnitude of the enhanced neural response was positively correlated with perceptual reports of the cued target being higher in contrast. The results suggest that attention increases the perceived contrast of visual stimuli by boosting early sensory processing in the visual cortex.

Adaptive optics for peripheral vision

NASA Astrophysics Data System (ADS)

Rosén, R.; Lundström, L.; Unsbo, P.

2012-07-01

Understanding peripheral optical errors and their impact on vision is important for various applications, e.g. research on myopia development and optical correction of patients with central visual field loss. In this study, we investigated whether correction of higher order aberrations with adaptive optics (AO) improve resolution beyond what is achieved with best peripheral refractive correction. A laboratory AO system was constructed for correcting peripheral aberrations. The peripheral low contrast grating resolution acuity in the 20° nasal visual field of the right eye was evaluated for 12 subjects using three types of correction: refractive correction of sphere and cylinder, static closed loop AO correction and continuous closed loop AO correction. Running AO in continuous closed loop improved acuity compared to refractive correction for most subjects (maximum benefit 0.15 logMAR). The visual improvement from aberration correction was highly correlated with the subject's initial amount of higher order aberrations (p = 0.001, R 2 = 0.72). There was, however, no acuity improvement from static AO correction. In conclusion, correction of peripheral higher order aberrations can improve low contrast resolution, provided refractive errors are corrected and the system runs in continuous closed loop.

What Drives Memory-Driven Attentional Capture? The Effects of Memory Type, Display Type, and Search Type

ERIC Educational Resources Information Center

Olivers, Christian N. L.

2009-01-01

An important question is 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. Some past research has indicated that they do: Singleton distractors interfered more strongly with a visual search task when they…

Improving Student Performance Using Nudge Analytics

ERIC Educational Resources Information Center

Feild, Jacqueline

2015-01-01

Providing students with continuous and personalized feedback on their performance is an important part of encouraging self regulated learning. As part of our higher education platform, we built a set of data visualizations to provide feedback to students on their assignment performance. These visualizations give students information about how they…

Extending Our Vision: Access to Inclusive Dance Education for People with Visual Impairment

ERIC Educational Resources Information Center

Seham, Jenny; Yeo, Anna J.

2015-01-01

Environmental, organizational and attitudinal obstacles continue to prevent people with vision loss from meaningfully engaging in dance education and performance. This article addresses the societal disabilities that handicap access to dance education for the blind. Although much of traditional dance instruction relies upon visual cuing and…

How an Exchange of Perspectives Led to Tentative Ethical Guidelines for Visual Ethnography

ERIC Educational Resources Information Center

Pope, Clive C.; De Luca, Rosemary; Tolich, Martin

2010-01-01

Qualitative research, especially visual ethnography, is an iterative not a linear process, replete with good intentions, false starts, mistaken assumptions, miscommunication and a continually revised statement of the problem. That the camera freezes everything and everyone in the frame only complicates ethical considerations. This work, jointly…

Unforgivable Blackness: Visual Rhetoric, Reader Response, and Critical Racial Literacy

ERIC Educational Resources Information Center

Gardner, Roberta Price

2017-01-01

Perceptions of black representations in literature and other visual mediums as positive or negative continuously cause consternation and debate (Fleetwood, 2011). Because African American children are literacy participants and consumers, they are not immune from experiencing this tension. This essay considers the effects and affective threads of…

Ophthalmic requirements and considerations for the en route air traffic control specialist : an ergonomic analysis of the visual work environment.

DOT National Transportation Integrated Search

1996-04-01

The Federal Air Surgeon requested continued investigation of visual disorders and vision corrective devices as to their relevance to the medical certification of airmen and controllers. The en route Air Traffic Control Specialist (ATCS) works with a ...

Visual Object Pattern Separation Varies in Older Adults

ERIC Educational Resources Information Center

Holden, Heather M.; Toner, Chelsea; Pirogovsky, Eva; Kirwan, C. Brock; Gilbert, Paul E.

2013-01-01

Young and nondemented older adults completed a visual object continuous recognition memory task in which some stimuli (lures) were similar but not identical to previously presented objects. The lures were hypothesized to result in increased interference and increased pattern separation demand. To examine variability in object pattern separation…

32 CFR 813.5 - Shipping or transmitting visual information documentation images.

Code of Federal Regulations, 2010 CFR

2010-07-01

... documentation images. 813.5 Section 813.5 National Defense Department of Defense (Continued) DEPARTMENT OF THE... visual information documentation images. (a) COMCAM images. Send COMCAM images to the DoD Joint Combat... the approval procedures that on-scene and theater commanders set. (b) Other non-COMCAM images. After...

32 CFR 813.5 - Shipping or transmitting visual information documentation images.

Code of Federal Regulations, 2013 CFR

2013-07-01

... documentation images. 813.5 Section 813.5 National Defense Department of Defense (Continued) DEPARTMENT OF THE... visual information documentation images. (a) COMCAM images. Send COMCAM images to the DoD Joint Combat... the approval procedures that on-scene and theater commanders set. (b) Other non-COMCAM images. After...

32 CFR 813.5 - Shipping or transmitting visual information documentation images.

Code of Federal Regulations, 2011 CFR

2011-07-01

... documentation images. 813.5 Section 813.5 National Defense Department of Defense (Continued) DEPARTMENT OF THE... visual information documentation images. (a) COMCAM images. Send COMCAM images to the DoD Joint Combat... the approval procedures that on-scene and theater commanders set. (b) Other non-COMCAM images. After...

32 CFR 813.5 - Shipping or transmitting visual information documentation images.

Code of Federal Regulations, 2012 CFR

2012-07-01

... documentation images. 813.5 Section 813.5 National Defense Department of Defense (Continued) DEPARTMENT OF THE... visual information documentation images. (a) COMCAM images. Send COMCAM images to the DoD Joint Combat... the approval procedures that on-scene and theater commanders set. (b) Other non-COMCAM images. After...

32 CFR 813.5 - Shipping or transmitting visual information documentation images.

Code of Federal Regulations, 2014 CFR

2014-07-01

... documentation images. 813.5 Section 813.5 National Defense Department of Defense (Continued) DEPARTMENT OF THE... visual information documentation images. (a) COMCAM images. Send COMCAM images to the DoD Joint Combat... the approval procedures that on-scene and theater commanders set. (b) Other non-COMCAM images. After...

47 CFR 78.111 - Frequency tolerance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES CABLE TELEVISION RELAY... shall maintain their operating frequency within 0.0005% the visual carrier, and the aural carrier shall be 4.5 MHz ±1 kHz above the visual carrier frequency. [52 FR 7145, Mar. 9, 1987, as amended at 68 FR...

Anatomical Evidence for Classical and Extra-classical Receptive Field Completion Across the Discontinuous Horizontal Meridian Representation of Primate Area V2

PubMed Central

Jeffs, Janelle; Ichida, Jennifer M.; Federer, Frederick

2009-01-01

In primates, a split of the horizontal meridian (HM) representation at the V2 rostral border divides this area into dorsal (V2d) and ventral (V2v) halves (representing lower and upper visual quadrants, respectively), causing retinotopically neighboring loci across the HM to be distant within V2. How is perceptual continuity maintained across this discontinuous HM representation? Injections of neuroanatomical tracers in marmoset V2d demonstrated that cells near the V2d rostral border can maintain retinotopic continuity within their classical and extra-classical receptive field (RF), by making both local and long-range intra- and interareal connections with ventral cortex representing the upper visual quadrant. V2d neurons located <0.9–1.3 mm from the V2d rostral border, whose RFs presumably do not cross the HM, make nonretinotopic horizontal connections with V2v neurons in the supra- and infragranular layers. V2d neurons located <0.6–0.9 mm from the border, whose RFs presumably cross the HM, in addition make retinotopic local connections with V2v neurons in layer 4. V2d neurons also make interareal connections with upper visual field regions of extrastriate cortex, but not of MT or MTc outside the foveal representation. Labeled connections in ventral cortex appear to represent the “missing” portion of the connectional fields in V2d across the HM. We conclude that connections between dorsal and ventral cortex can create visual field continuity within a second-order discontinuous visual topography. PMID:18755777

How Visual Management for Continuous Improvement Might Guide and Affect Hospital Staff: A Case Study.

PubMed

Ulhassan, Waqar; von Thiele Schwarz, Ulrica; Westerlund, Hugo; Sandahl, Christer; Thor, Johan

2015-01-01

Visual management (VM) tools such as whiteboards, often employed in Lean thinking applications, are intended to be helpful in improving work processes in different industries including health care. It remains unclear, however, how VM is actually applied in health care Lean interventions and how it might influence the clinical staff. We therefore examined how Lean-inspired VM using whiteboards for continuous improvement efforts related to the hospital staff's work and collaboration. Within a case study design, we combined semistructured interviews, nonparticipant observations, and photography on 2 cardiology wards. The fate of VM differed between the 2 wards; in one, it was well received by the staff and enhanced continuous improvement efforts, whereas in the other ward, it was not perceived to fit in the work flow or to make enough sense in order to be sustained. Visual management may enable the staff and managers to allow communication across time and facilitate teamwork by enabling the inclusion of team members who are not present simultaneously; however, its adoption and value seem contingent on finding a good fit with the local context. A combination of continuous improvement and VM may be helpful in keeping the staff engaged in the change process in the long run.

Combining Video, Audio and Lexical Indicators of Affect in Spontaneous Conversation via Particle Filtering

PubMed Central

Savran, Arman; Cao, Houwei; Shah, Miraj; Nenkova, Ani; Verma, Ragini

2013-01-01

We present experiments on fusing facial video, audio and lexical indicators for affect estimation during dyadic conversations. We use temporal statistics of texture descriptors extracted from facial video, a combination of various acoustic features, and lexical features to create regression based affect estimators for each modality. The single modality regressors are then combined using particle filtering, by treating these independent regression outputs as measurements of the affect states in a Bayesian filtering framework, where previous observations provide prediction about the current state by means of learned affect dynamics. Tested on the Audio-visual Emotion Recognition Challenge dataset, our single modality estimators achieve substantially higher scores than the official baseline method for every dimension of affect. Our filtering-based multi-modality fusion achieves correlation performance of 0.344 (baseline: 0.136) and 0.280 (baseline: 0.096) for the fully continuous and word level sub challenges, respectively. PMID:25300451

Combining Video, Audio and Lexical Indicators of Affect in Spontaneous Conversation via Particle Filtering.

PubMed

Savran, Arman; Cao, Houwei; Shah, Miraj; Nenkova, Ani; Verma, Ragini

2012-01-01

We present experiments on fusing facial video, audio and lexical indicators for affect estimation during dyadic conversations. We use temporal statistics of texture descriptors extracted from facial video, a combination of various acoustic features, and lexical features to create regression based affect estimators for each modality. The single modality regressors are then combined using particle filtering, by treating these independent regression outputs as measurements of the affect states in a Bayesian filtering framework, where previous observations provide prediction about the current state by means of learned affect dynamics. Tested on the Audio-visual Emotion Recognition Challenge dataset, our single modality estimators achieve substantially higher scores than the official baseline method for every dimension of affect. Our filtering-based multi-modality fusion achieves correlation performance of 0.344 (baseline: 0.136) and 0.280 (baseline: 0.096) for the fully continuous and word level sub challenges, respectively.

Visual and flight performance recovery after PRK or LASIK in helicopter pilots.

PubMed

Van de Pol, Corina; Greig, Joanna L; Estrada, Art; Bissette, Gina M; Bower, Kraig S

2007-06-01

Refractive surgery, specifically photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK), is becoming more accepted in the military environment. Determination of the impact on visual performance in the more demanding aviation environment was the impetus for this study. A prospective evaluation of 20 Black Hawk pilots pre-surgically and at 1 wk, 1 mo, and 6 mo postsurgery was conducted to assess both PRK and LASIK visual and flight performance outcomes on the return of aviators to duty. Of 20 pilots, 19 returned to flight status at 1 mo after surgery; 1 PRK subject was delayed due to corneal haze and subjective visual symptoms. Improvements were seen under simulator night and night vision goggle flight after LASIK; no significant changes in flight performance were measured in the aircraft. Results indicated a significantly faster recovery of all visual performance outcomes 1 wk after LASIK vs. PRK, with no difference between procedures at 1 and 6 mo. Low contrast acuity and contrast sensitivity only weakly correlated to flight performance in the early post-operative period. Overall flight performance assessed in this study after PRK and LASIK was stable or improved from baseline, indicating a resilience of performance despite measured decrements in visual performance, especially in PRK. More visually demanding flight tasks may be impacted by subtle changes in visual performance. Contrast tests are more sensitive to the effects of refractive surgical intervention and may prove to be a better indicator of visual recovery for return to flight status.

Large Terrain Modeling and Visualization for Planets

NASA Technical Reports Server (NTRS)

Myint, Steven; Jain, Abhinandan; Cameron, Jonathan; Lim, Christopher

2011-01-01

Physics-based simulations are actively used in the design, testing, and operations phases of surface and near-surface planetary space missions. One of the challenges in realtime simulations is the ability to handle large multi-resolution terrain data sets within models as well as for visualization. In this paper, we describe special techniques that we have developed for visualization, paging, and data storage for dealing with these large data sets. The visualization technique uses a real-time GPU-based continuous level-of-detail technique that delivers multiple frames a second performance even for planetary scale terrain model sizes.

The Impact of Continuity Editing in Narrative Film on Event Segmentation

PubMed Central

Magliano, Joseph P.; Zacks, Jeffrey M.

2011-01-01

Filmmakers use continuity editing to engender a sense of situational continuity or discontinuity at editing boundaries. The goal of this study was to assess the impact of continuity editing on how people perceive the structure of events in a narrative film and to identify brain networks that are associated with the processing of different types of continuity editing boundaries. Participants viewed a commercially produced film and segmented it into meaningful events while brain activity was recorded with functional MRI. We identified three degrees of continuity that can occur at editing locations: edits that are continuous in space, time, and action; edits that are discontinuous in space or time but continuous in action; and edits that are discontinuous in action as well as space or time. Discontinuities in action had the biggest impact on behavioral event segmentation and discontinuities in space and time had minor effects. Edits were associated with large transient increases in early visual areas. Spatial-temporal changes and action changes produced strikingly different patterns of transient change, and provided evidence that specialized mechanisms in higher-order perceptual processing regions are engaged to maintain continuity of action in the face of spatiotemporal discontinuities. These results suggest that commercial film editing is shaped to support the comprehension of meaningful events that bridge breaks in low-level visual continuity, and even breaks in continuity of spatial and temporal location. PMID:21972849

Efficacy of a pressure-sensing mattress cover system for reducing interface pressure: study protocol for a randomized controlled trial.

PubMed

Wong, Holly; Kaufman, Jaime; Baylis, Barry; Conly, John M; Hogan, David B; Stelfox, Henry T; Southern, Danielle A; Ghali, William A; Ho, Chester H

2015-09-29

Interface pressure is a key risk factor in the development of pressure ulcers. Visual feedback of continuous interface pressure between the body and support surface could inform clinicians on repositioning strategies and play a key role in an overall strategy for the prevention and management of pressure ulcers. A parallel two-group randomized controlled clinical trial will be conducted to study the effect of continuous pressure imaging on reducing interface pressure and on the incidence of pressure ulcers in vulnerable hospital patients. A total of 678 eligible consenting inpatients at risk of pressure ulcer development in a tertiary acute care institution will be randomly allocated to either having the ForeSite PT™ system with the liquid-crystal display monitor turned on to provide visual feedback to the clinicians while also collecting continuous interface pressure data (intervention group) or to having the ForeSite PT™ system with monitor turned off (that is, not providing visual feedback) but still collecting continuous interface pressure data (control group), in a ratio of 1:1. Continuous interface pressure data will be collected in both groups for 3 days (72 h). Data collection will continue until discharge for a subset of approximately 60 patients. The primary outcome will be the differences in the two groups' interface pressure analysis. Interface pressure readings will be collected through hourly samplings of continuous interface pressure recordings. Secondary outcomes will be the differences between the two groups in pressure-related skin and soft tissue changes in areas at risk of pressure ulcer (obtained at baseline within 24 h of admission) and on the third day of the trial or at discharge and perceptions of the intervention by patients and clinicians (obtained on the third day or at discharge). This will be the first randomized controlled trial to investigate the effect of visual feedback with continuous interface pressure of vulnerable hospital patients across different care settings, and the association between interface pressure and development of pressure-related skin and soft tissue changes. The results could provide important information to guide clinical practice in the prevention and management of pressure ulcers. ClinicalTrials.gov NCT02325388 (date of registration: 24 December 2014).

Learning a visuomotor rotation: simultaneous visual and proprioceptive information is crucial for visuomotor remapping.

PubMed

Shabbott, Britne A; Sainburg, Robert L

2010-05-01

Visuomotor adaptation is mediated by errors between intended and sensory-detected arm positions. However, it is not clear whether visual-based errors that are shown during the course of motion lead to qualitatively different or more efficient adaptation than errors shown after movement. For instance, continuous visual feedback mediates online error corrections, which may facilitate or inhibit the adaptation process. We addressed this question by manipulating the timing of visual error information and task instructions during a visuomotor adaptation task. Subjects were exposed to a visuomotor rotation, during which they received continuous visual feedback (CF) of hand position with instructions to correct or not correct online errors, or knowledge-of-results (KR), provided as a static hand-path at the end of each trial. Our results showed that all groups improved performance with practice, and that online error corrections were inconsequential to the adaptation process. However, in contrast to the CF groups, the KR group showed relatively small reductions in mean error with practice, increased inter-trial variability during rotation exposure, and more limited generalization across target distances and workspace. Further, although the KR group showed improved performance with practice, after-effects were minimal when the rotation was removed. These findings suggest that simultaneous visual and proprioceptive information is critical in altering neural representations of visuomotor maps, although delayed error information may elicit compensatory strategies to offset perturbations.

Reduced change blindness suggests enhanced attention to detail in individuals with autism.

PubMed

Smith, Hayley; Milne, Elizabeth

2009-03-01

The phenomenon of change blindness illustrates that a limited number of items within the visual scene are attended to at any one time. It has been suggested that individuals with autism focus attention on less contextually relevant aspects of the visual scene, show superior perceptual discrimination and notice details which are often ignored by typical observers. In this study we investigated change blindness in autism by asking participants to detect continuity errors deliberately introduced into a short film. Whether the continuity errors involved central/marginal or social/non-social aspects of the visual scene was varied. Thirty adolescent participants, 15 with autistic spectrum disorder (ASD) and 15 typically developing (TD) controls participated. The participants with ASD detected significantly more errors than the TD participants. Both groups identified more errors involving central rather than marginal aspects of the scene, although this effect was larger in the TD participants. There was no difference in the number of social or non-social errors detected by either group of participants. In line with previous data suggesting an abnormally broad attentional spotlight and enhanced perceptual function in individuals with ASD, the results of this study suggest enhanced awareness of the visual scene in ASD. The results of this study could reflect superior top-down control of visual search in autism, enhanced perceptual function, or inefficient filtering of visual information in ASD.

Stereoscopic visual fatigue assessment and modeling

NASA Astrophysics Data System (ADS)

Wang, Danli; Wang, Tingting; Gong, Yue

2014-03-01

Evaluation of stereoscopic visual fatigue is one of the focuses in the user experience research. It is measured in either subjective or objective methods. Objective measures are more preferred for their capability to quantify the degree of human visual fatigue without being affected by individual variation. However, little research has been conducted on the integration of objective indicators, or the sensibility of each objective indicator in reflecting subjective fatigue. The paper proposes a simply effective method to evaluate visual fatigue more objectively. The stereoscopic viewing process is divided into series of sessions, after each of which viewers rate their visual fatigue with subjective scores (SS) according to a five-grading scale, followed by tests of the punctum maximum accommodation (PMA) and visual reaction time (VRT). Throughout the entire viewing process, their eye movements are recorded by an infrared camera. The pupil size (PS) and percentage of eyelid closure over the pupil over time (PERCLOS) are extracted from the videos processed by the algorithm. Based on the method, an experiment with 14 subjects was conducted to assess visual fatigue induced by 3D images on polarized 3D display. The experiment consisted of 10 sessions (5min per session), each containing the same 75 images displayed randomly. The results show that PMA, VRT and PERCLOS are the most efficient indicators of subjective visual fatigue and finally a predictive model is derived from the stepwise multiple regressions.

The Effects of Visual Beats on Prosodic Prominence: Acoustic Analyses, Auditory Perception and Visual Perception

ERIC Educational Resources Information Center

Krahmer, Emiel; Swerts, Marc

2007-01-01

Speakers employ acoustic cues (pitch accents) to indicate that a word is important, but may also use visual cues (beat gestures, head nods, eyebrow movements) for this purpose. Even though these acoustic and visual cues are related, the exact nature of this relationship is far from well understood. We investigate whether producing a visual beat…

PREDICT: Pattern Representation and Evaluation of Data through Integration, Correlation, and Transformation

DTIC Science & Technology

2015-10-01

overview visualization to help clinicians identify patients that are changing and inserted these indices into the sepsis specific decision support...visualization, 4) Created a sepsis identification visualization tool to help clinicians identify patients headed for septic shock, and 5) Generated a...5 Sepsis Visualization

Visual Attention to Antismoking PSAs: Smoking Cues versus Other Attention-Grabbing Features

ERIC Educational Resources Information Center

Sanders-Jackson, Ashley N.; Cappella, Joseph N.; Linebarger, Deborah L.; Piotrowski, Jessica Taylor; O'Keeffe, Moira; Strasser, Andrew A.

2011-01-01

This study examines how addicted smokers attend visually to smoking-related public service announcements (PSAs) in adults smokers. Smokers' onscreen visual fixation is an indicator of cognitive resources allocated to visual attention. Characteristic of individuals with addictive tendencies, smokers are expected to be appetitively activated by…

Region-Specific Slowing of Alpha Oscillations is Associated with Visual-Perceptual Abilities in Children Born Very Preterm

PubMed Central

Doesburg, Sam M.; Moiseev, Alexander; Herdman, Anthony T.; Ribary, Urs; Grunau, Ruth E.

2013-01-01

Children born very preterm (≤32 weeks gestational age) without major intellectual or neurological impairments often express selective deficits in visual-perceptual abilities. The alterations in neurophysiological development underlying these problems, however, remain poorly understood. Recent research has indicated that spontaneous alpha oscillations are slowed in children born very preterm, and that atypical alpha-mediated functional network connectivity may underlie selective developmental difficulties in visual-perceptual ability in this group. The present study provides the first source-resolved analysis of slowing of spontaneous alpha oscillations in very preterm children, indicating alterations in a distributed set of brain regions concentrated in areas of posterior parietal and inferior temporal regions associated with visual perception, as well as prefrontal cortical regions and thalamus. We also uniquely demonstrate that slowing of alpha oscillations is associated with selective difficulties in visual-perceptual ability in very preterm children. These results indicate that region-specific slowing of alpha oscillations contribute to selective developmental difficulties prevalent in this population. PMID:24298250

Correlation between visual function and refractive, topographic, pachymetric and aberrometric data in eyes with keratoconus

PubMed Central

Bayraktar Bilen, Neslihan; Hepsen, Ibrahim F.; Arce, Carlos G.

2016-01-01

AIM To analyze the relationship between two visual functions and refractive, topographic, pachymetric and aberrometric indicators in eyes with keratoconus. METHODS Corrected distance visual acuity (CDVA), and letter contrast sensitivity (CS) were correlated with refraction, corneal topography, pachymetry, and total corneal wavefront data prospectively in 71 eyes with keratoconus. The topographic indices assessed were simulated keratometry for the flattest and steepest meridians (SimK1 and SimK2), posterior steeper K (Ks), elevation value in best-fit sphere (BFS) maps, squared eccentricity (Є2), aspheric asymmetric index (AAI), pachymetry, thickness progression index (TPI), the amount of pachymetric decentralization (APD), and GalileiTM-keratoconus indices. RESULTS The mean CDVA (expressed as logMAR) were 0.25±0.21. The mean CS was 1.25±0.46. The spherical refraction correlated well with CDVA (r=-0.526, P<0.001). From topographic indices, SRI correlated with CS (r=-0.695), and IAI with CS (r=-0.672) (P<0.001 for all). Root mean square (RMS) was 4.3±1.81 µm, spherical aberration (SA) was -0.4±0.67 µm, vertical and horizontal coma were -2.1±1.47 and -0.4±0.72 µm. All wavefront data (except horizontal coma), AAI, Є2 and maximum BFS correlated significantly with the visual function (P≤0.001 for all). CONCLUSION In this study, CS is more affected than CDVA as a visual function. The quantity and quality of vision is significantly correlated with well-known and new topographic indices. There is not a significant correlation between visual function and pachymetric parameters. The significantly correlated indices can be used in staging keratoconus and to follow the outcome of a treatment. PMID:27588266

The changing pattern of cataract surgery indications: a 5-year study of 2 cataract surgery databases.

PubMed

Lundström, Mats; Goh, Pik-Pin; Henry, Ype; Salowi, Mohamad A; Barry, Peter; Manning, Sonia; Rosen, Paul; Stenevi, Ulf

2015-01-01

The aim of this study was to describe changes over time in the indications and outcomes of cataract surgery and to discuss optimal timing for the surgery. Database study. Patients who had undergone cataract extraction in the Netherlands, Sweden, or Malaysia from 2008 through 2012. We analyzed preoperative, surgical, and postoperative data from 2 databases: the European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO) and the Malaysian National Cataract Registry. The EUREQUO contains complete data from the national cataract registries in the Netherlands and Sweden. Preoperative and postoperative corrected distance visual acuity, preoperative ocular comorbidity in the surgery eye, and capsule complications during surgery. There were substantial differences in indication for surgery between the 3 national data sets. The percentage of eyes with a preoperative best-corrected visual acuity of 20/200 or worse varied from 7.1% to 72%. In all 3 data sets, the visual thresholds for cataract surgery decreased over time by 6% to 28% of the baseline values. The frequency of capsule complications varied between the 3 data sets, from 1.1% to 3.7% in 2008 and from 0.6% to 2.7% in 2012. An increasing postoperative visual acuity was also seen for all 3 data sets. A high frequency of capsule complication was related significantly to poor preoperative visual acuity, and a high frequency of decreased visual acuity after surgery was related significantly to excellent preoperative visual acuity. The 5-year trend in all 3 national data sets showed decreasing visual thresholds for surgery, decreasing surgical complication rates, and increasing visual outcomes regardless of the initial preoperative visual level. Cataract surgery on eyes with poor preoperative visual acuity was related to surgical complications, and cataract surgery on eyes with excellent preoperative visual acuity was related to adverse visual results. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

"Cuts in Action": A High-Density EEG Study Investigating the Neural Correlates of Different Editing Techniques in Film.

PubMed

Heimann, Katrin S; Uithol, Sebo; Calbi, Marta; Umiltà, Maria A; Guerra, Michele; Gallese, Vittorio

2017-08-01

In spite of their striking differences with real-life perception, films are perceived and understood without effort. Cognitive film theory attributes this to the system of continuity editing, a system of editing guidelines outlining the effect of different cuts and edits on spectators. A major principle in this framework is the 180° rule, a rule recommendation that, to avoid spectators' attention to the editing, two edited shots of the same event or action should not be filmed from angles differing in a way that expectations of spatial continuity are strongly violated. In the present study, we used high-density EEG to explore the neural underpinnings of this rule. In particular, our analysis shows that cuts and edits in general elicit early ERP component indicating the registration of syntactic violations as known from language, music, and action processing. However, continuity edits and cuts-across the line differ from each other regarding later components likely to be indicating the differences in spatial remapping as well as in the degree of conscious awareness of one's own perception. Interestingly, a time-frequency analysis of the occipital alpha rhythm did not support the hypothesis that such differences in processing routes are mainly linked to visual attention. On the contrary, our study found specific modulations of the central mu rhythm ERD as an indicator of sensorimotor activity, suggesting that sensorimotor networks might play an important role. We think that these findings shed new light on current discussions about the role of attention and embodied perception in film perception and should be considered when explaining spectators' different experience of different kinds of cuts. Copyright © 2016 Cognitive Science Society, Inc.

Dangerous animals capture and maintain attention in humans.

PubMed

Yorzinski, Jessica L; Penkunas, Michael J; Platt, Michael L; Coss, Richard G

2014-05-28

Predation is a major source of natural selection on primates and may have shaped attentional processes that allow primates to rapidly detect dangerous animals. Because ancestral humans were subjected to predation, a process that continues at very low frequencies, we examined the visual processes by which men and women detect dangerous animals (snakes and lions). We recorded the eye movements of participants as they detected images of a dangerous animal (target) among arrays of nondangerous animals (distractors) as well as detected images of a nondangerous animal (target) among arrays of dangerous animals (distractors). We found that participants were quicker to locate targets when the targets were dangerous animals compared with nondangerous animals, even when spatial frequency and luminance were controlled. The participants were slower to locate nondangerous targets because they spent more time looking at dangerous distractors, a process known as delayed disengagement, and looked at a larger number of dangerous distractors. These results indicate that dangerous animals capture and maintain attention in humans, suggesting that historical predation has shaped some facets of visual orienting and its underlying neural architecture in modern humans.

Bottom-up and top-down influences at untrained conditions determine perceptual learning specificity and transfer

PubMed Central

Xiong, Ying-Zi; Zhang, Jun-Yun; Yu, Cong

2016-01-01

Perceptual learning is often orientation and location specific, which may indicate neuronal plasticity in early visual areas. However, learning specificity diminishes with additional exposure of the transfer orientation or location via irrelevant tasks, suggesting that the specificity is related to untrained conditions, likely because neurons representing untrained conditions are neither bottom-up stimulated nor top-down attended during training. To demonstrate these top-down and bottom-up contributions, we applied a “continuous flash suppression” technique to suppress the exposure stimulus into sub-consciousness, and with additional manipulations to achieve pure bottom-up stimulation or top-down attention with the transfer condition. We found that either bottom-up or top-down influences enabled significant transfer of orientation and Vernier discrimination learning. These results suggest that learning specificity may result from under-activations of untrained visual neurons due to insufficient bottom-up stimulation and/or top-down attention during training. High-level perceptual learning thus may not functionally connect to these neurons for learning transfer. DOI: http://dx.doi.org/10.7554/eLife.14614.001 PMID:27377357

Interactive archives of scientific data

NASA Technical Reports Server (NTRS)

Treinish, Lloyd A.

1994-01-01

A focus on qualitative methods of presenting data shows that visualization provides a mechanism for browsing independent of the source of data and is an effective alternative to traditional image-based browsing of image data. To be generally applicable, such visualization methods, however, must be based upon an underlying data model with support for a broad class of data types and structures. Interactive, near-real-time browsing for data sets of interesting size today requires a browse server of considerable power. A symmetric multi-processor with very high internal and external bandwidth demonstrates the feasibility of this concept. Although this technology is likely to be available on the desktop within a few years, the increase in the size and complexity of achieved data will continue to exceed the capacity of 'worksation' systems. Hence, a higher class of performance, especially in bandwidth, will generally be required for on-demand browsing. A few experiments with differing digital compression techniques indicates that a MPEG-1 implementation within the context of a high-performance browse server (i.e., parallized) is a practical method of converting a browse product to a form suitable for network or CD-ROM distribution.

Surface mapping of spike potential fields: experienced EEGers vs. computerized analysis.

PubMed

Koszer, S; Moshé, S L; Legatt, A D; Shinnar, S; Goldensohn, E S

1996-03-01

An EEG epileptiform spike focus recorded with scalp electrodes is clinically localized by visual estimation of the point of maximal voltage and the distribution of its surrounding voltages. We compared such estimated voltage maps, drawn by experienced electroencephalographers (EEGers), with a computerized spline interpolation technique employed in the commercially available software package FOCUS. Twenty-two spikes were recorded from 15 patients during long-term continuous EEG monitoring. Maps of voltage distribution from the 28 electrodes surrounding the points of maximum change in slope (the spike maximum) were constructed by the EEGer. The same points of maximum spike and voltage distributions at the 29 electrodes were mapped by computerized spline interpolation and a comparison between the two methods was made. The findings indicate that the computerized spline mapping techniques employed in FOCUS construct voltage maps with similar maxima and distributions as the maps created by experienced EEGers. The dynamics of spike activity, including correlations, are better visualized using the computerized technique than by manual interpretation alone. Its use as a technique for spike localization is accurate and adds information of potential clinical value.

Improving the Audio Game-Playing Performances of People with Visual Impairments through Multimodal Training

ERIC Educational Resources Information Center

Balan, Oana; Moldoveanu, Alin; Moldoveanu, Florica; Nagy, Hunor; Wersenyi, Gyorgy; Unnporsson, Runar

2017-01-01

Introduction: As the number of people with visual impairments (that is, those who are blind or have low vision) is continuously increasing, rehabilitation and engineering researchers have identified the need to design sensory-substitution devices that would offer assistance and guidance to these people for performing navigational tasks. Auditory…

Models Provide Specificity: Testing a Proposed Mechanism of Visual Working Memory Capacity Development

ERIC Educational Resources Information Center

Simmering, Vanessa R.; Patterson, Rebecca

2012-01-01

Numerous studies have established that visual working memory has a limited capacity that increases during childhood. However, debate continues over the source of capacity limits and its developmental increase. Simmering (2008) adapted a computational model of spatial cognitive development, the Dynamic Field Theory, to explain not only the source…

Writing through Big Data: New Challenges and Possibilities for Data-Driven Arguments

ERIC Educational Resources Information Center

Beveridge, Aaron

2017-01-01

As multimodal writing continues to shift and expand in the era of Big Data, writing studies must confront the new challenges and possibilities emerging from data mining, data visualization, and data-driven arguments. Often collected under the broad banner of "data literacy," students' experiences of data visualization and data-driven…

Learning to Look for Language: Development of Joint Attention in Young Deaf Children

ERIC Educational Resources Information Center

Lieberman, Amy M.; Hatrak, Marla; Mayberry, Rachel I.

2014-01-01

Joint attention between hearing children and their caregivers is typically achieved when the adult provides spoken, auditory linguistic input that relates to the child's current visual focus of attention. Deaf children interacting through sign language must learn to continually switch visual attention between people and objects in order to achieve…

Context and Occasion Setting in "Drosophila" Visual Learning

ERIC Educational Resources Information Center

Brembs, Bjorn; Wiener, Jan

2006-01-01

In a permanently changing environment, it is by no means an easy task to distinguish potentially important events from negligible ones. Yet, to survive, every animal has to continuously face that challenge. How does the brain accomplish this feat? Building on previous work in "Drosophila melanogaster" visual learning, we have developed an…

Ocular-Motor Function and Information Processing: Implications for the Reading Process.

ERIC Educational Resources Information Center

Leisman, Gerald; Schwartz, Joddy

This paper discusses the dichotomy between continually moving eyes and the lack of blurred visual experience. A discontinuous model of visual perception is proposed, with the discontinuities being phase and temporally related to saccadic eye movements. It is further proposed that deviant duration and angular velocity characteristics of saccades in…

Blended Learning in the Visual Communications Classroom: Student Reflections on a Multimedia Course

ERIC Educational Resources Information Center

George-Palilonis, Jennifer; Filak, Vincent

2009-01-01

Advances in digital technology and a rapidly evolving media landscape continue to dramatically change teaching and learning. Among these changes is the emergence of multimedia teaching and learning tools, online degree programs, and hybrid classes that blend traditional and digital content delivery. At the same time, visual communication programs…

Multidimensional Shape Similarity in the Development of Visual Object Classification

ERIC Educational Resources Information Center

Mash, Clay

2006-01-01

The current work examined age differences in the classification of novel object images that vary in continuous dimensions of structural shape. The structural dimensions employed are two that share a privileged status in the visual analysis and representation of objects: the shape of discrete prominent parts and the attachment positions of those…

Visual tracking using neuromorphic asynchronous event-based cameras.

PubMed

Ni, Zhenjiang; Ieng, Sio-Hoi; Posch, Christoph; Régnier, Stéphane; Benosman, Ryad

2015-04-01

This letter presents a novel computationally efficient and robust pattern tracking method based on a time-encoded, frame-free visual data. Recent interdisciplinary developments, combining inputs from engineering and biology, have yielded a novel type of camera that encodes visual information into a continuous stream of asynchronous, temporal events. These events encode temporal contrast and intensity locally in space and time. We show that the sparse yet accurately timed information is well suited as a computational input for object tracking. In this letter, visual data processing is performed for each incoming event at the time it arrives. The method provides a continuous and iterative estimation of the geometric transformation between the model and the events representing the tracked object. It can handle isometry, similarities, and affine distortions and allows for unprecedented real-time performance at equivalent frame rates in the kilohertz range on a standard PC. Furthermore, by using the dimension of time that is currently underexploited by most artificial vision systems, the method we present is able to solve ambiguous cases of object occlusions that classical frame-based techniques handle poorly.

Bodily-visual practices and turn continuation

PubMed Central

Ford, Cecilia E.; Thompson, Sandra A.; Drake, Veronika

2012-01-01

This paper considers points in turn construction where conversation researchers have shown that talk routinely continues beyond possible turn completion, but where we find bodily-visual behavior doing such turn extension work. The bodily-visual behaviors we examine share many features with verbal turn extensions, but we argue that embodied movements have distinct properties that make them well-suited for specific kinds of social action, including stance display and by-play in sequences framed as subsidiary to a simultaneous and related verbal exchange. Our study is in line with a research agenda taking seriously the point made by Goodwin (2000a, b, 2003), Hayashi (2003, 2005), Iwasaki (2009), and others that scholars seeking to account for practices in language and social interaction do themselves a disservice if they privilege the verbal dimension; rather, as suggested in Stivers/Sidnell (2005), each semiotic system/modality, while coordinated with others, has its own organization. With the current exploration of bodily-visual turn extensions, we hope to contribute to a growing understanding of how these different modes of organization are managed concurrently and in concert by interactants in carrying out their everyday social actions. PMID:23526861

Reduction in Dynamic Visual Acuity Reveals Gaze Control Changes Following Spaceflight

NASA Technical Reports Server (NTRS)

Peters, Brian T.; Brady, Rachel A.; Miller, Chris; Lawrence, Emily L.; Mulavara Ajitkumar P.; Bloomberg, Jacob J.

2010-01-01

INTRODUCTION: Exposure to microgravity causes adaptive changes in eye-head coordination that can lead to altered gaze control. This could affect postflight visual acuity during head and body motion. The goal of this study was to characterize changes in dynamic visual acuity after long-duration spaceflight. METHODS: Dynamic Visual Acuity (DVA) data from 14 astro/cosmonauts were collected after long-duration (6 months) spaceflight. The difference in acuity between seated and walking conditions provided a metric of change in the subjects ability to maintain gaze fixation during self-motion. In each condition, a psychophysical threshold detection algorithm was used to display Landolt ring optotypes at a size that was near each subject s acuity threshold. Verbal responses regarding the orientation of the gap were recorded as the optotypes appeared sequentially on a computer display 4 meters away. During the walking trials, subjects walked at 6.4 km/h on a motorized treadmill. RESULTS: A decrement in mean postflight DVA was found, with mean values returning to baseline within 1 week. The population mean showed a consistent improvement in DVA performance, but it was accompanied by high variability. A closer examination of the individual subject s recovery curves revealed that many did not follow a pattern of continuous improvement with each passing day. When adjusted on the basis of previous long-duration flight experience, the population mean shows a "bounce" in the re-adaptation curve. CONCLUSION: Gaze control during self-motion is altered following long-duration spaceflight and changes in postflight DVA performance indicate that vestibular re-adaptation may be more complex than a gradual return to normal.

Effect of Direct Glare on Orbicularis Oculi and Trapezius During Computer Reading.

PubMed

Mork, Randi; Bruenech, Jan Richard; Thorud, Hanne Mari Schiøtz

2016-07-01

Unfavorable visual conditions during computer work may affect development of both eyestrain and musculoskeletal pain in the neck and shoulder area. The aim of the study was to investigate how direct glare affects symptom development, muscle activity, and muscle blood flow in m. orbicularis oculi and m. trapezius during reading on a computer screen. Fifteen healthy young adults with normal binocular vision read text on a computer screen at an optimized computer workplace, 30 minutes with glare exposure and 30 minutes with appropriate lighting. Postural angles were continuously registered. Development of eye symptoms and musculoskeletal pain in the neck and shoulder area were recorded using VAS scales. Muscle activity and muscle blood flow were measured continuously using electromyography and photoplethysmography, respectively. Glare exposure resulted in significantly more pronounced eye pain, increased orbicularis muscle activity, and increased trapezius blood flow compared to reading with appropriate lighting. There were no significant differences in posture between the two light conditions. There were also significant associations between orbicularis oculi activity and both trapezius blood flow and neck pain during both conditions. Results from the current study show that direct glare conditions cause increased eyestrain and orbicularis oculi contraction during reading on a computer screen. This study also indicates that exposure to direct glare affects the trapezius muscle, possibly by an interaction between the visual system, sympathetic nervous system, and head-stabilizing muscles. In addition, there were associations between the use of orbicularis oculi, trapezius blood flow, and development of neck pain independent of the lighting.

Effectiveness of transcranial direct current stimulation and visual illusion on neuropathic pain in spinal cord injury

PubMed Central

Kumru, Hatice; Pelayo, Raul; Vidal, Joan; Tormos, Josep Maria; Fregni, Felipe; Navarro, Xavier; Pascual-Leone, Alvaro

2010-01-01

The aim of this study was to evaluate the analgesic effect of transcranial direct current stimulation of the motor cortex and techniques of visual illusion, applied isolated or combined, in patients with neuropathic pain following spinal cord injury. In a sham controlled, double-blind, parallel group design, 39 patients were randomized into four groups receiving transcranial direct current stimulation with walking visual illusion or with control illusion and sham stimulation with visual illusion or with control illusion. For transcranial direct current stimulation, the anode was placed over the primary motor cortex. Each patient received ten treatment sessions during two consecutive weeks. Clinical assessment was performed before, after the last day of treatment, after 2 and 4 weeks follow-up and after 12 weeks. Clinical assessment included overall pain intensity perception, Neuropathic Pain Symptom Inventory and Brief Pain Inventory. The combination of transcranial direct current stimulation and visual illusion reduced the intensity of neuropathic pain significantly more than any of the single interventions. Patients receiving transcranial direct current stimulation and visual illusion experienced a significant improvement in all pain subtypes, while patients in the transcranial direct current stimulation group showed improvement in continuous and paroxysmal pain, and those in the visual illusion group improved only in continuous pain and dysaesthesias. At 12 weeks after treatment, the combined treatment group still presented significant improvement on the overall pain intensity perception, whereas no improvements were reported in the other three groups. Our results demonstrate that transcranial direct current stimulation and visual illusion can be effective in the management of neuropathic pain following spinal cord injury, with minimal side effects and with good tolerability. PMID:20685806

The Role of Prediction In Perception: Evidence From Interrupted Visual Search

PubMed Central

Mereu, Stefania; Zacks, Jeffrey M.; Kurby, Christopher A.; Lleras, Alejandro

2014-01-01

Recent studies of rapid resumption—an observer’s ability to quickly resume a visual search after an interruption—suggest that predictions underlie visual perception. Previous studies showed that when the search display changes unpredictably after the interruption, rapid resumption disappears. This conclusion is at odds with our everyday experience, where the visual system seems to be quite efficient despite continuous changes of the visual scene; however, in the real world, changes can typically be anticipated based on previous knowledge. The present study aimed to evaluate whether changes to the visual display can be incorporated into the perceptual hypotheses, if observers are allowed to anticipate such changes. Results strongly suggest that an interrupted visual search can be rapidly resumed even when information in the display has changed after the interruption, so long as participants not only can anticipate them, but also are aware that such changes might occur. PMID:24820440

A vision fusion treatment system based on ATtiny26L

NASA Astrophysics Data System (ADS)

Zhang, Xiaoqing; Zhang, Chunxi; Wang, Jiqiang

2006-11-01

Vision fusion treatment is an important and effective project to strabismus children. The vision fusion treatment system based on the principle for eyeballs to follow the moving visual survey pole is put forward first. In this system the original position of visual survey pole is about 35 centimeters far from patient's face before its moving to the middle position between the two eyeballs. The eyeballs of patient will follow the movement of the visual survey pole. When they can't follow, one or two eyeballs will turn to other position other than the visual survey pole. This displacement is recorded every time. A popular single chip microcomputer ATtiny26L is used in this system, which has a PWM output signal to control visual survey pole to move with continuously variable speed. The movement of visual survey pole accords to the modulating law of eyeballs to follow visual survey pole.

People-oriented Information Visualization Design

NASA Astrophysics Data System (ADS)

Chen, Zhiyong; Zhang, Bolun

2018-04-01

In the 21st century with rapid development, in the wake of the continuous progress of science and technology, human society enters the information era and the era of big data, and the lifestyle and aesthetic system also change accordingly, so the emerging field of information visualization is increasingly popular. Information visualization design is the process of visualizing all kinds of tedious information data, so as to quickly accept information and save time-cost. Along with the development of the process of information visualization, information design, also becomes hotter and hotter, and emotional design, people-oriented design is an indispensable part of in the design of information. This paper probes information visualization design through emotional analysis of information design based on the social context of people-oriented experience from the perspective of art design. Based on the three levels of emotional information design: instinct level, behavior level and reflective level research, to explore and discuss information visualization design.

Visualization and understanding of the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging.

PubMed

Vercruysse, Jurgen; Toiviainen, Maunu; Fonteyne, Margot; Helkimo, Niko; Ketolainen, Jarkko; Juuti, Mikko; Delaet, Urbain; Van Assche, Ivo; Remon, Jean Paul; Vervaet, Chris; De Beer, Thomas

2014-04-01

Over the last decade, there has been increased interest in the application of twin screw granulation as a continuous wet granulation technique for pharmaceutical drug formulations. However, the mixing of granulation liquid and powder material during the short residence time inside the screw chamber and the atypical particle size distribution (PSD) of granules produced by twin screw granulation is not yet fully understood. Therefore, this study aims at visualizing the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging. In first instance, the residence time of material inside the barrel was investigated as function of screw speed and moisture content followed by the visualization of the granulation liquid distribution as function of different formulation and process parameters (liquid feed rate, liquid addition method, screw configuration, moisture content and barrel filling degree). The link between moisture uniformity and granule size distributions was also studied. For residence time analysis, increased screw speed and lower moisture content resulted to a shorter mean residence time and narrower residence time distribution. Besides, the distribution of granulation liquid was more homogenous at higher moisture content and with more kneading zones on the granulator screws. After optimization of the screw configuration, a two-level full factorial experimental design was performed to evaluate the influence of moisture content, screw speed and powder feed rate on the mixing efficiency of the powder and liquid phase. From these results, it was concluded that only increasing the moisture content significantly improved the granulation liquid distribution. This study demonstrates that NIR chemical imaging is a fast and adequate measurement tool for allowing process visualization and hence for providing better process understanding of a continuous twin screw granulation system. Copyright © 2013 Elsevier B.V. All rights reserved.

Human infrared vision is triggered by two-photon chromophore isomerization

PubMed Central

Palczewska, Grazyna; Vinberg, Frans; Stremplewski, Patrycjusz; Bircher, Martin P.; Salom, David; Komar, Katarzyna; Zhang, Jianye; Cascella, Michele; Wojtkowski, Maciej; Kefalov, Vladimir J.; Palczewski, Krzysztof

2014-01-01

Vision relies on photoactivation of visual pigments in rod and cone photoreceptor cells of the retina. The human eye structure and the absorption spectra of pigments limit our visual perception of light. Our visual perception is most responsive to stimulating light in the 400- to 720-nm (visible) range. First, we demonstrate by psychophysical experiments that humans can perceive infrared laser emission as visible light. Moreover, we show that mammalian photoreceptors can be directly activated by near infrared light with a sensitivity that paradoxically increases at wavelengths above 900 nm, and display quadratic dependence on laser power, indicating a nonlinear optical process. Biochemical experiments with rhodopsin, cone visual pigments, and a chromophore model compound 11-cis-retinyl-propylamine Schiff base demonstrate the direct isomerization of visual chromophore by a two-photon chromophore isomerization. Indeed, quantum mechanics modeling indicates the feasibility of this mechanism. Together, these findings clearly show that human visual perception of near infrared light occurs by two-photon isomerization of visual pigments. PMID:25453064

Augmenting white cane reliability using smart glove for visually impaired people.

PubMed

Bernieri, Giuseppe; Faramondi, Luca; Pascucci, Federica

2015-08-01

The independent mobility problem of visually impaired people has been an active research topic in biomedical engineering: although many smart tools have been proposed, traditional tools (e.g., the white cane) continue to play a prominent role. In this paper a low cost smart glove is presented: the key idea is to minimize the impact in using it by combining the traditional tools with a technological device able to improve the movement performance of the visually impaired people.

Increased internal higher-order aberrations as a useful parameter for indication of vitrectomy in three asteroid hyalosis cases

PubMed Central

Yokoyama, Sho; Kojima, Takashi; Kaga, Tatsushi; Ichikawa, Kazuo

2015-01-01

We report three asteroid hyalosis cases in which internal higher-order aberrations (HOAs) were improved concomitant with improved visual symptoms after vitrectomy. Cases 1 and 2 reported severe floaters and glare disability, although their visual acuities were fairly good. Case 3 showed poor visual acuity since this patient also suffered from mild macular degeneration. For these three asteroid hyalosis cases, we were unsure if treatment with vitrectomy could improve visual symptoms. Therefore, we measured internal HOAs with an aberrometer, and found that the internal HOA values in these cases were high. We suspected that internal high HOAs values were associated with visual disturbance, and performed vitrectomy. After the vitrectomy, the internal HOA values in these three asteroid hyalosis cases markedly decreased, and visual symptoms improved. These observations suggested that measurement of internal HOAs may be useful to determine the indication for vitrectomy. PMID:26698200

Multi-modal information processing for visual workload relief

NASA Technical Reports Server (NTRS)

Burke, M. W.; Gilson, R. D.; Jagacinski, R. J.

1980-01-01

The simultaneous performance of two single-dimensional compensatory tracking tasks, one with the left hand and one with the right hand, is discussed. The tracking performed with the left hand was considered the primary task and was performed with a visual display or a quickened kinesthetic-tactual (KT) display. The right-handed tracking was considered the secondary task and was carried out only with a visual display. Although the two primary task displays had afforded equivalent performance in a critical tracking task performed alone, in the dual-task situation the quickened KT primary display resulted in superior secondary visual task performance. Comparisons of various combinations of primary and secondary visual displays in integrated or separated formats indicate that the superiority of the quickened KT display is not simply due to the elimination of visual scanning. Additional testing indicated that quickening per se also is not the immediate cause of the observed KT superiority.

Increased internal higher-order aberrations as a useful parameter for indication of vitrectomy in three asteroid hyalosis cases.

PubMed

Yokoyama, Sho; Kojima, Takashi; Kaga, Tatsushi; Ichikawa, Kazuo

2015-12-23

We report three asteroid hyalosis cases in which internal higher-order aberrations (HOAs) were improved concomitant with improved visual symptoms after vitrectomy. Cases 1 and 2 reported severe floaters and glare disability, although their visual acuities were fairly good. Case 3 showed poor visual acuity since this patient also suffered from mild macular degeneration. For these three asteroid hyalosis cases, we were unsure if treatment with vitrectomy could improve visual symptoms. Therefore, we measured internal HOAs with an aberrometer, and found that the internal HOA values in these cases were high. We suspected that internal high HOAs values were associated with visual disturbance, and performed vitrectomy. After the vitrectomy, the internal HOA values in these three asteroid hyalosis cases markedly decreased, and visual symptoms improved. These observations suggested that measurement of internal HOAs may be useful to determine the indication for vitrectomy. 2015 BMJ Publishing Group Ltd.

Interactive visualization of public health indicators to support policymaking: An exploratory study

PubMed Central

Zakkar, Moutasem; Sedig, Kamran

2017-01-01

Purpose The purpose of this study is to examine the use of interactive visualizations to represent data/information related to social determinants of health and public health indicators, and to investigate the benefits of such visualizations for health policymaking. Methods: The study developed a prototype for an online interactive visualization tool that represents the social determinants of health. The study participants explored and used the tool. The tool was evaluated using the informal user experience evaluation method. This method involves the prospective users of a tool to use and play with it and their feedback to be collected through interviews. Results: Using visualizations to represent and interact with health indicators has advantages over traditional representation techniques that do not allow users to interact with the information. Communicating healthcare indicators to policymakers is a complex task because of the complexity of the indicators, diversity of audiences, and different audience needs. This complexity can lead to information misinterpretation, which occurs when users of the health data ignore or do not know why, where, and how the data has been produced, or where and how it can be used. Conclusions: Public health policymaking is a complex process, and data is only one element among others needed in this complex process. Researchers and healthcare organizations should conduct a strategic evaluation to assess the usability of interactive visualizations and decision support tools before investing in these tools. Such evaluation should take into consideration the cost, ease of use, learnability, and efficiency of those tools, and the factors that influence policymaking. PMID:29026455

Surface Meteorology at Teller Site Stations, Seward Peninsula, Alaska, Ongoing from 2016

DOE Data Explorer

Bob Busey; Bob Bolton; Cathy Wilson; Lily Cohen

2017-12-05

Meteorological data are currently being collected at two locations at the Teller Site, Seward Peninsula. Teller Creek Station near TL_BSV (TELLER BOTTOM METEOROLOGICAL STATION) Station is located in the lower watershed in a tussock / willow transition zone and co-located with continuous snow depth measurements and subsurface measurements. Teller Creek Station near TL_IS_5 (TELLER TOP METEOROLOGICAL STATION) Station is located in the upper watershed and co-located with continuous snow depth measurements and subsurface measurements. Two types of data products are provided for these stations: First, meteorological and site characterization data grouped by sensor/measurement type (e.g., radiation or soil pit temperature and moisture). These are *.csv files. Second, a Data Visualization tool is provided for quick visualization of measurements over time at a station. Download the *_Visualizer.zip file, extract, and click on the 'index.html' file. Data values are the same in both products.

Beta oscillations define discrete perceptual cycles in the somatosensory domain.

PubMed

Baumgarten, Thomas J; Schnitzler, Alfons; Lange, Joachim

2015-09-29

Whether seeing a movie, listening to a song, or feeling a breeze on the skin, we coherently experience these stimuli as continuous, seamless percepts. However, there are rare perceptual phenomena that argue against continuous perception but, instead, suggest discrete processing of sensory input. Empirical evidence supporting such a discrete mechanism, however, remains scarce and comes entirely from the visual domain. Here, we demonstrate compelling evidence for discrete perceptual sampling in the somatosensory domain. Using magnetoencephalography (MEG) and a tactile temporal discrimination task in humans, we find that oscillatory alpha- and low beta-band (8-20 Hz) cycles in primary somatosensory cortex represent neurophysiological correlates of discrete perceptual cycles. Our results agree with several theoretical concepts of discrete perceptual sampling and empirical evidence of perceptual cycles in the visual domain. Critically, these results show that discrete perceptual cycles are not domain-specific, and thus restricted to the visual domain, but extend to the somatosensory domain.

A computational exploration of complementary learning mechanisms in the primate ventral visual pathway.

PubMed

Spoerer, Courtney J; Eguchi, Akihiro; Stringer, Simon M

2016-02-01

In order to develop transformation invariant representations of objects, the visual system must make use of constraints placed upon object transformation by the environment. For example, objects transform continuously from one point to another in both space and time. These two constraints have been exploited separately in order to develop translation and view invariance in a hierarchical multilayer model of the primate ventral visual pathway in the form of continuous transformation learning and temporal trace learning. We show for the first time that these two learning rules can work cooperatively in the model. Using these two learning rules together can support the development of invariance in cells and help maintain object selectivity when stimuli are presented over a large number of locations or when trained separately over a large number of viewing angles. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Visual Rhetoric in the Curriculum: Pedagogy for a Multimodal Workplace

ERIC Educational Resources Information Center

Brumberger, Eva R.

2005-01-01

A survey of BizCom listserv subscribers suggests that visual rhetoric receives relatively little attention within business communication curricula. Results indicate that programs typically do not require a course in visual rhetoric, and on average, 20% or less of teaching in undergraduate courses is dedicated to visual communication. The findings…

Attentional load modulates responses of human primary visual cortex to invisible stimuli.

PubMed

Bahrami, Bahador; Lavie, Nilli; Rees, Geraint

2007-03-20

Visual neuroscience has long sought to determine the extent to which stimulus-evoked activity in visual cortex depends on attention and awareness. Some influential theories of consciousness maintain that the allocation of attention is restricted to conscious representations [1, 2]. However, in the load theory of attention [3], competition between task-relevant and task-irrelevant stimuli for limited-capacity attention does not depend on conscious perception of the irrelevant stimuli. The critical test is whether the level of attentional load in a relevant task would determine unconscious neural processing of invisible stimuli. Human participants were scanned with high-field fMRI while they performed a foveal task of low or high attentional load. Irrelevant, invisible monocular stimuli were simultaneously presented peripherally and were continuously suppressed by a flashing mask in the other eye [4]. Attentional load in the foveal task strongly modulated retinotopic activity evoked in primary visual cortex (V1) by the invisible stimuli. Contrary to traditional views [1, 2, 5, 6], we found that availability of attentional capacity determines neural representations related to unconscious processing of continuously suppressed stimuli in human primary visual cortex. Spillover of attention to cortical representations of invisible stimuli (under low load) cannot be a sufficient condition for their awareness.

Attention and response control in ADHD. Evaluation through integrated visual and auditory continuous performance test.

PubMed

Moreno-García, Inmaculada; Delgado-Pardo, Gracia; Roldán-Blasco, Carmen

2015-03-03

This study assesses attention and response control through visual and auditory stimuli in a primary care pediatric sample. The sample consisted of 191 participants aged between 7 and 13 years old. It was divided into 2 groups: (a) 90 children with ADHD, according to diagnostic (DSM-IV-TR) (APA, 2002) and clinical (ADHD Rating Scale-IV) (DuPaul, Power, Anastopoulos, & Reid, 1998) criteria, and (b) 101 children without a history of ADHD. The aims were: (a) to determine and compare the performance of both groups in attention and response control, (b) to identify attention and response control deficits in the ADHD group. Assessments were carried out using the Integrated Visual and Auditory Continuous Performance Test (IVA/CPT, Sandford & Turner, 2002). Results showed that the ADHD group had visual and auditory attention deficits, F(3, 170) = 14.38; p < .01, deficits in fine motor regulation (Welch´s t-test = 44.768; p < .001) and sensory/motor activity (Welch'st-test = 95.683, p < .001; Welch's t-test = 79.537, p < .001). Both groups exhibited a similar performance in response control, F(3, 170) = .93, p = .43.Children with ADHD showed inattention, mental processing speed deficits, and loss of concentration with visual stimuli. Both groups yielded a better performance in attention with auditory stimuli.

Memory-guided attention during active viewing of edited dynamic scenes.

PubMed

Valuch, Christian; König, Peter; Ansorge, Ulrich

2017-01-01

Films, TV shows, and other edited dynamic scenes contain many cuts, which are abrupt transitions from one video shot to the next. Cuts occur within or between scenes, and often join together visually and semantically related shots. Here, we tested to which degree memory for the visual features of the precut shot facilitates shifting attention to the postcut shot. We manipulated visual similarity across cuts, and measured how this affected covert attention (Experiment 1) and overt attention (Experiments 2 and 3). In Experiments 1 and 2, participants actively viewed a target movie that randomly switched locations with a second, distractor movie at the time of the cuts. In Experiments 1 and 2, participants were able to deploy attention more rapidly and accurately to the target movie's continuation when visual similarity was high than when it was low. Experiment 3 tested whether this could be explained by stimulus-driven (bottom-up) priming by feature similarity, using one clip at screen center that was followed by two alternative continuations to the left and right. Here, even the highest similarity across cuts did not capture attention. We conclude that following cuts of high visual similarity, memory-guided attention facilitates the deployment of attention, but this effect is (top-down) dependent on the viewer's active matching of scene content across cuts.

Continuous cognitive improvement 1 year following successful kidney transplant.

PubMed

Harciarek, Michał; Biedunkiewicz, Bogdan; Lichodziejewska-Niemierko, Monika; Dębska-Ślizień, Alicja; Rutkowski, Bolesław

2011-06-01

Successful kidney transplantation was recently shown to lead to improvement in the cognitive performance of patients on chronic dialysis. To examine whether the early cognitive benefits of transplantation continue to develop over time, along with the patients' ongoing recovery, we addressed these questions in a prospective controlled study of 27 dialyzed patients who subsequently received a kidney transplant, 18 dialyzed patients awaiting kidney transplant, and 30 matched controls without kidney disease. Overall, successful kidney transplant contributed to a statistically significant improvement in performance on tests of motor/psychomotor speed, visual planning, memory, and abstract reasoning tested 1 year later. We also studied whether the cognitive performance of patients maintained on dialysis is stable or declines over time and found that it actually declined over this time even in adequately dialyzed patients. Measures of memory functions were particularly affected. This study indicates that the early beneficial effects of transplantation are not transient and were still evident 1 year following transplantation.

The global burden of cataract.

PubMed

Rao, Gullapalli N; Khanna, Rohit; Payal, Abhishek

2011-01-01

To review the previous year's literature related to prevalence of blindness in general, blindness due to cataract, cataract surgical coverage (CSC) and cataract surgical rates (CSRs). Cataracts are the major cause of blindness and visual impairment in developing countries and contributes to more than 90% of the total disability adjusted life years. This review shows that coverage continues to be a problem in many countries, especially for the female population, those residing in rural areas and those who are illiterate. Although CSR is an indicator of the availability and acceptability of services, for measuring the impact of the program, we should look at combining CSR with CSC. This strategy would also enable us achieve our goal of eliminating avoidable blindness due to cataracts by the year 2020. Cataracts still continue- to be a major cause of blindness globally and with the rapidly aging population, it is a challenge to tackle. We need to plan a comprehensive strategy addressing issues related to availability, affordability, accessibility and acceptability of eye-care services.

[Cataract surgery under topical anesthesia with oral anticoagulants].

PubMed

Wirbelauer, C; Weller, A; Häberle, H; Pham, D T

2004-09-01

Approximately 14 % of cataract surgery patients receive blood-thinning agents. In a prospective study, the influence of oral anticoagulants on intraoperative and postoperative hemorrhages in patients undergoing cataract surgery in topical anesthesia was investigated. 128 patients presenting for cataract surgery under oral anticoagulation were included. The mean preoperative prothrombin time was 39 +/- 18 %. Most patients (81 %) continued their oral anticoagulation (prothrombin time 34 +/- 13 %). All surgeries were performed in topical anesthesia. In 9 patients (7 %) an ocular hemorrhagic event was observed. These were not sight-threatening and resorbed spontaneously within a few days. Only one patient (0.8 %) had a slight hemorrhage in the anterior chamber. There were no differences (P > 0.05) between patients with or without hemorrhagic complications in the postoperative visual acuity, the intraocular pressure, the prothrombin time or the discontinuation of oral anticoagulants. Cataract surgery in topical anesthesia under oral anticoagulation did not increase the risk of sight-threatening hemorrhages. The continuation of oral anticoagulation seems particularly indicated for ambulatory cataract surgery.

The effects of adults' affective expression and direction of visual gaze on 12-month-olds' visual preferences for an object following a 5-minute, 1-day, or 1-month delay.

PubMed

Flom, Ross; Johnson, Sarah

2011-03-01

Between 12- and 14 months of age infants begin to use another's direction of gaze and affective expression in learning about various objects and events. What is not well understood is how long infants' behaviour towards a previously unfamiliar object continues to be influenced following their participation in circumstances of social referencing. In this experiment, we examined infants' sensitivity to an adult's direction of gaze and their visual preference for one of two objects following a 5-min, 1-day, or 1-month delay. Ninety-six 12-month-olds participated. For half of the infants during habituation (i.e., familiarization), the adults' direction of gaze was directed towards an unfamiliar object (look condition). For the remaining half of the infants during habituation, the adults' direction of gaze was directed away from the unfamiliar object (look-away condition). All infants were habituated to two events. One event consisted of an adult looking towards (look condition) or away from (look-away condition) an object while facially and vocally conveying a positive affective expression. The second event consisted of the same adult looking towards or away from a different object while conveying a disgusted affective expression. Following the habituation phase and a 5-min, 1-day, or 1-month delay, infants' visual preference was assessed. During the visual preference phase, infants saw the two objects side by side where the adult conveying the affective expression was not visible. Results of the visual preference phase indicate that infants in the look condition showed a significant preference for object previously paired with the positive affect following a 5-min and 1-day delay. No significant visual preference was found in the look condition following a 1-month delay. No significant preferences were found at any retention interval in the look-away condition. Results are discussed in terms of early learning, social referencing, and early memory. ©2010 The British Psychological Society.

The nucleus of the optic tract. Its function in gaze stabilization and control of visual-vestibular interaction

NASA Technical Reports Server (NTRS)

Cohen, B.; Reisine, H.; Yokota, J. I.; Raphan, T.

1992-01-01

1. Electrical stimulation of the nucleus of the optic tract (NOT) induced nystagmus and after-nystagmus with ipsilateral slow phases. The velocity characteristics of the nystagmus were similar to those of the slow component of optokinetic nystagmus (OKN) and to optokinetic after-nystagmus (OKAN), both of which are produced by velocity storage in the vestibular system. When NOT was destroyed, these components disappeared. This indicates that velocity storage is activated from the visual system through NOT. 2. Velocity storage produces compensatory eye-in-head and head-on-body movements through the vestibular system. The association of NOT with velocity storage implies that NOT helps stabilize gaze in space during both passive motion and active locomotion in light with an angular component. It has been suggested that "vestibular-only" neurons in the vestibular nuclei play an important role in generation of velocity storage. Similarities between the rise and fall times of eye velocity during OKN and OKAN to firing rates of vestibular-only neurons suggest that these cells may receive their visual input through NOT. 3. One NOT was injected with muscimol, a GABAA agonist. Ipsilateral OKN and OKAN were lost, suggesting that GABA, which is an inhibitory transmitter in NOT, acts on projection pathways to the brain stem. A striking finding was that visual suppression and habituation of contralateral slow phases of vestibular nystagmus were also abolished after muscimol injection. The latter implies that NOT plays an important role in producing visual suppression of the VOR and habituating its time constant. 4. Habituation is lost after nodulus and uvula lesions and visual suppression after lesions of the flocculus and paraflocculus. We postulate that the disappearance of vestibular habituation and of visual suppression of vestibular responses after muscimol injections was due to dysfacilitation of the prominent NOT-inferior olive pathway, inactivating climbing fibers from the dorsal cap to nodulouvular and flocculoparafloccular Purkinje cells. The prompt loss of habituation when NOT was inactivated, and its return when the GABAergic inhibition dissipated, suggests that although VOR habituation can be relatively permanent, it must be maintained continuously by activity of the vestibulocerebellum.

Visual examination apparatus

NASA Technical Reports Server (NTRS)

Haines, R. F.; Fitzgerald, J. W.; Rositano, S. A. (Inventor)

1976-01-01

An automated visual examination apparatus for measuring visual sensitivity and mapping blind spot location including a projection system for displaying to a patient a series of visual stimuli. A response switch enables him to indicate his reaction to the stimuli, and a recording system responsive to both the visual stimuli per se and the patient's response. The recording system thereby provides a correlated permanent record of both stimuli and response from which a substantive and readily apparent visual evaluation can be made.

Effects of continuous visual feedback during sitting balance training in chronic stroke survivors.

PubMed

Pellegrino, Laura; Giannoni, Psiche; Marinelli, Lucio; Casadio, Maura

2017-10-16

Postural control deficits are common in stroke survivors and often the rehabilitation programs include balance training based on visual feedback to improve the control of body position or of the voluntary shift of body weight in space. In the present work, a group of chronic stroke survivors, while sitting on a force plate, exercised the ability to control their Center of Pressure with a training based on continuous visual feedback. The goal of this study was to test if and to what extent chronic stroke survivors were able to learn the task and transfer the learned ability to a condition without visual feedback and to directions and displacement amplitudes different from those experienced during training. Eleven chronic stroke survivors (5 Male - 6 Female, age: 59.72 ± 12.84 years) participated in this study. Subjects were seated on a stool positioned on top of a custom-built force platform. Their Center of Pressure positions were mapped to the coordinate of a cursor on a computer monitor. During training, the cursor position was always displayed and the subjects were to reach targets by shifting their Center of Pressure by moving their trunk. Pre and post-training subjects were required to reach without visual feedback of the cursor the training targets as well as other targets positioned in different directions and displacement amplitudes. During training, most stroke survivors were able to perform the required task and to improve their performance in terms of duration, smoothness, and movement extent, although not in terms of movement direction. However, when we removed the visual feedback, most of them had no improvement with respect to their pre-training performance. This study suggests that postural training based exclusively on continuous visual feedback can provide limited benefits for stroke survivors, if administered alone. However, the positive gains observed during training justify the integration of this technology-based protocol in a well-structured and personalized physiotherapy training, where the combination of the two approaches may lead to functional recovery.

Visual acuity in adults with Asperger's syndrome: no evidence for "eagle-eyed" vision.

PubMed

Falkmer, Marita; Stuart, Geoffrey W; Danielsson, Henrik; Bram, Staffan; Lönebrink, Mikael; Falkmer, Torbjörn

2011-11-01

Autism spectrum conditions (ASC) are defined by criteria comprising impairments in social interaction and communication. Altered visual perception is one possible and often discussed cause of difficulties in social interaction and social communication. Recently, Ashwin et al. suggested that enhanced ability in local visual processing in ASC was due to superior visual acuity, but that study has been the subject of methodological criticism, placing the findings in doubt. The present study investigated visual acuity thresholds in 24 adults with Asperger's syndrome and compared their results with 25 control subjects with the 2 Meter 2000 Series Revised ETDRS Chart. The distribution of visual acuities within the two groups was highly similar, and none of the participants had superior visual acuity. Superior visual acuity in individuals with Asperger's syndrome could not be established, suggesting that differences in visual perception in ASC are not explained by this factor. A continued search for explanations of superior ability in local visual processing in persons with ASC is therefore warranted. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Evaluation of deck durability on continuous beam highway bridges.

DOT National Transportation Integrated Search

1985-01-01

In an effort to determine the extent of deck cracking on continuous steel beam bridges and the effect of the cracking on deck durability, 137 structures were visually inspected and 5 of these were selected for detailed evaluation. The general survey ...

Attention Cueing and Activity Equally Reduce False Alarm Rate in Visual-Auditory Associative Learning through Improving Memory.

PubMed

Nikouei Mahani, Mohammad-Ali; Haghgoo, Hojjat Allah; Azizi, Solmaz; Nili Ahmadabadi, Majid

2016-01-01

In our daily life, we continually exploit already learned multisensory associations and form new ones when facing novel situations. Improving our associative learning results in higher cognitive capabilities. We experimentally and computationally studied the learning performance of healthy subjects in a visual-auditory sensory associative learning task across active learning, attention cueing learning, and passive learning modes. According to our results, the learning mode had no significant effect on learning association of congruent pairs. In addition, subjects' performance in learning congruent samples was not correlated with their vigilance score. Nevertheless, vigilance score was significantly correlated with the learning performance of the non-congruent pairs. Moreover, in the last block of the passive learning mode, subjects significantly made more mistakes in taking non-congruent pairs as associated and consciously reported lower confidence. These results indicate that attention and activity equally enhanced visual-auditory associative learning for non-congruent pairs, while false alarm rate in the passive learning mode did not decrease after the second block. We investigated the cause of higher false alarm rate in the passive learning mode by using a computational model, composed of a reinforcement learning module and a memory-decay module. The results suggest that the higher rate of memory decay is the source of making more mistakes and reporting lower confidence in non-congruent pairs in the passive learning mode.

Long-term Live-cell Imaging to Assess Cell Fate in Response to Paclitaxel.

PubMed

Bolgioni, Amanda F; Vittoria, Marc A; Ganem, Neil J

2018-05-14

Live-cell imaging is a powerful technique that can be used to directly visualize biological phenomena in single cells over extended periods of time. Over the past decade, new and innovative technologies have greatly enhanced the practicality of live-cell imaging. Cells can now be kept in focus and continuously imaged over several days while maintained under 37 °C and 5% CO2 cell culture conditions. Moreover, multiple fields of view representing different experimental conditions can be acquired simultaneously, thus providing high-throughput experimental data. Live-cell imaging provides a significant advantage over fixed-cell imaging by allowing for the direct visualization and temporal quantitation of dynamic cellular events. Live-cell imaging can also identify variation in the behavior of single cells that would otherwise have been missed using population-based assays. Here, we describe live-cell imaging protocols to assess cell fate decisions following treatment with the anti-mitotic drug paclitaxel. We demonstrate methods to visualize whether mitotically arrested cells die directly from mitosis or slip back into interphase. We also describe how the fluorescent ubiquitination-based cell cycle indicator (FUCCI) system can be used to assess the fraction of interphase cells born from mitotic slippage that are capable of re-entering the cell cycle. Finally, we describe a live-cell imaging method to identify nuclear envelope rupture events.

Vividness of visual imagery and social desirable responding: correlations of the vividness of visual imagery questionnaire with the balanced inventory of desirable responding and the Marlowe-Crowne scale.

PubMed

Allbutt, John; Ling, Jonathan; Rowley, Martin; Shafiullah, Mohammed

2011-09-01

Correlational research investigating the relationship between scores on self-report imagery questionnaires and measures of social desirable responding has shown only a weak association. However, researchers have argued that this research may have underestimated the size of the relationship because it relied primarily on the Marlowe-Crowne scale (MC; Crowne & Marlowe, Journal of Consulting Psychology, 24, 349-354, 1960), which loads primarily on the least relevant form of social desirable responding for this particular context, the moralistic bias. Here we report the analysis of data correlating the Vividness of Visual Imagery Questionnaire (VVIQ; Marks, Journal of Mental Imagery, 19, 153-166, 1973) with the Balanced Inventory of Desirable Responding (BIDR; Paulhus, 2002) and the MC scale under anonymous testing conditions. The VVIQ correlated significantly with the Self-Deceptive Enhancement (SDE) and Agency Management (AM) BIDR subscales and with the MC. The largest correlation was with SDE. The ability of SDE to predict VVIQ scores was not significantly enhanced by adding either AM or MC. Correlations between the VVIQ and BIDR egoistic scales were larger when the BIDR was continuously rather than dichotomously scored. This analysis indicates that the relationship between self-reported imagery and social desirable responding is likely to be stronger than previously thought.

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.

Misremembering what you see or hear: Dissociable effects of modality on short- and long-term false recognition.

PubMed

Olszewska, Justyna M; Reuter-Lorenz, Patricia A; Munier, Emily; Bendler, Sara A

2015-09-01

False working memories readily emerge using a visual item-recognition variant of the converging associates task. Two experiments, manipulating study and test modality, extended prior working memory results by demonstrating a reliable false recognition effect (more false alarms to associatively related lures than to unrelated lures) within seconds of encoding in either the visual or auditory modality. However, false memories were nearly twice as frequent when study lists were seen than when they were heard, regardless of test modality, although study-test modality mismatch was generally disadvantageous (consistent with encoding specificity). A final experiment that varied study-test modality using a hybrid short- and long-term memory test (Flegal, Atkins & Reuter-Lorenz, 2010) replicated the auditory advantage in the short term but revealed a reversal in the long term: The false memory effect was greater in the auditory study-test condition than in the visual study-test condition. Thus, the same encoding conditions gave rise to an opposite modality advantage depending on whether recognition was tested under short-term or long-term memory conditions. Although demonstrating continuity in associative processing across delay, the results indicate that delay condition affects the availability of modality-dependent features of the memory trace and, thus, distinctiveness, leading to dissociable patterns of short- and long-term memory performance. (c) 2015 APA, all rights reserved).

Developmental memory capacity resources of typical children retrieving picture communication symbols using direct selection and visual linear scanning with fixed communication displays.

PubMed

Wagner, Barry T; Jackson, Heather M

2006-02-01

This study examined the cognitive demands of 2 selection techniques in augmentative and alternative communication (AAC), direct selection, and visual linear scanning, by determining the memory retrieval abilities of typically developing children when presented with fixed communication displays. One hundred twenty typical children from kindergarten, 1st, and 3rd grades were randomly assigned to either a direct selection or visual linear scanning group. Memory retrieval was assessed through word span using Picture Communication Symbols (PCSs). Participants were presented various numbers and arrays of PCSs and asked to retrieve them by placing identical graphic symbols on fixed communication displays with grid layouts. The results revealed that participants were able to retrieve more PCSs during direct selection than scanning. Additionally, 3rd-grade children retrieved more PCSs than kindergarten and 1st-grade children. An analysis on the type of errors during retrieval indicated that children were more successful at retrieving the correct PCSs than the designated location of those symbols on fixed communication displays. AAC practitioners should consider using direct selection over scanning whenever possible and account for anticipatory monitoring and pulses when scanning is used in the service delivery of children with little or no functional speech. Also, researchers should continue to investigate AAC selection techniques in relationship to working memory resources.

A distributed code for color in natural scenes derived from center-surround filtered cone signals

PubMed Central

Kellner, Christian J.; Wachtler, Thomas

2013-01-01

In the retina of trichromatic primates, chromatic information is encoded in an opponent fashion and transmitted to the lateral geniculate nucleus (LGN) and visual cortex via parallel pathways. Chromatic selectivities of neurons in the LGN form two separate clusters, corresponding to two classes of cone opponency. In the visual cortex, however, the chromatic selectivities are more distributed, which is in accordance with a population code for color. Previous studies of cone signals in natural scenes typically found opponent codes with chromatic selectivities corresponding to two directions in color space. Here we investigated how the non-linear spatio-chromatic filtering in the retina influences the encoding of color signals. Cone signals were derived from hyper-spectral images of natural scenes and preprocessed by center-surround filtering and rectification, resulting in parallel ON and OFF channels. Independent Component Analysis (ICA) on these signals yielded a highly sparse code with basis functions that showed spatio-chromatic selectivities. In contrast to previous analyses of linear transformations of cone signals, chromatic selectivities were not restricted to two main chromatic axes, but were more continuously distributed in color space, similar to the population code of color in the early visual cortex. Our results indicate that spatio-chromatic processing in the retina leads to a more distributed and more efficient code for natural scenes. PMID:24098289

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.

An Indicator Approach to Assessing Benefits of Carbon Sequestration and Other Ecosystem Services

NASA Astrophysics Data System (ADS)

Dale, V. H.; Kline, K. L.; Parish, E. S.

2017-12-01

While geoengineering offers one approach to carbon management, another tactic is providing land owners and managers with incentives to more efficiently and consistently increase carbon stocks and storage in soils and above ground. Growing bioenergy crops entails such an option. Landscape design can help identify where different strategies best fit into the larger framework of resource management to achieve desired stakeholder objectives. Our research goal is to develop means to assess management options and identify those that offer the highest degree of sustainability as measured by the provision to society of specific economic, environmental and social services with the least costs. Oak Ridge National Laboratory (ORNL) has worked with the US Department of Energy to develop an approach for assessing progress toward better management to improve sustainability. This approach involves six steps with decisions made at each step. First the scope of the assessment is established based on the particular context and options. Next indicators that pertain to the objective are selected and prioritized. Then, baselines and targets are determined for each indicator. Fourth, indicator values are measured, collected, and evaluated. Once the values are in hand, trends and tradeoffs in the indicator set are analyzed. The final step seeks to define and deploy good practices for the activity. ORNL's proposed checklist of environmental and socioeconomic indicators includes greenhouse gases and soil quality (including carbon) and emphasizes that changes in carbon stocks must be viewed in terms of their effects on other indicators, such as those for water quality and quantity, biodiversity, air quality, and productivity as well as on socioeconomic costs and benefits. The framework developed to select and evaluate indicators and assess progress toward sustainability goals is being encapsulated into a visualization tool. Visualization will inform stakeholders about potential effects of decisions, allowing them to make choices that can have better outcomes than might have occurred otherwise. The concept of continual improvement forms the core of developing more sustainable development pathways, including those that will lead to carbon-negative systems.

Comparison of Descemet stripping under continuous air flow, manual air injection and balanced salt solution for DMEK: a pilot study.

PubMed

Gabbay, I E; Bahar, I; Nahum, Y; Livny, E

2017-08-01

Descemet's membrane endothelial keratoplasty (DMEK) involves removal of the recipient's Descemet membrane (DM) prior to transplanting the donor's DM. When using balanced salt solution (BSS) or ophthalmic viscosurgical devices (OVDs), visualization of the host's DM during its stripping may be inadequate and may result in Descemet remnants and could lead to sub-optimal surgical results. Previous articles described excellent visualization when utilizing air injection but this requires repeated air injection into the anterior chamber (AC). We present a pilot study that compares different techniques under which DM stripping can be performed: with continuous automated air infusion, with manual air infusion, and with BSS. We retrospectively compared video footage of DM stripping with BSS, with continuous air and with manual injection of air into the AC to determine DM stripping duration and the number of times the surgeon had to insert and retrieve a surgical instrument from the AC. Thirty videos of 10 consecutive cases of the three DM stripping techniques were evaluated. DM stripping duration was 3.26 (±1.32), 3.92 (±1.2) and 12.9 (±3.98) minutes for BSS, continuous air flow, and manual air injection, respectively. Frequency of instrument retrieval (FIR) was 3.6 (±1.71), 1.5 (±0.71) and 15.1 (±3.28) for BSS, continuous air flow, and manual air injection, respectively. Continuous air flow and BSS were both statistically different than manual air injection into the AC (p < 0.05), but did not differ from one another statistically. DM stripping during posterior lamellar surgery is imperative for favorable post-operative results and prevention of complications. Performing this step under air in the AC contributes to better visualization and an efficient surgery.

Directed Forgetting and Directed Remembering in Visual Working Memory

PubMed Central

Williams, Melonie; Woodman, Geoffrey F.

2013-01-01

A defining characteristic of visual working memory is its limited capacity. This means that it is crucial to maintain only the most relevant information in visual working memory. However, empirical research is mixed as to whether it is possible to selectively maintain a subset of the information previously encoded into visual working memory. Here we examined the ability of subjects to use cues to either forget or remember a subset of the information already stored in visual working memory. In Experiment 1, participants were cued to either forget or remember one of two groups of colored squares during a change-detection task. We found that both types of cues aided performance in the visual working memory task, but that observers benefited more from a cue to remember than a cue to forget a subset of the objects. In Experiment 2, we show that the previous findings, which indicated that directed-forgetting cues are ineffective, were likely due to the presence of invalid cues that appear to cause observers to disregard such cues as unreliable. In Experiment 3, we recorded event-related potentials (ERPs) and show that an electrophysiological index of focused maintenance is elicited by cues that indicate which subset of information in visual working memory needs to be remembered, ruling out alternative explanations of the behavioral effects of retention-interval cues. The present findings demonstrate that observers can focus maintenance mechanisms on specific objects in visual working memory based on cues indicating future task relevance. PMID:22409182

Multisensory Integration Strategy for Modality-Specific Loss of Inhibition Control in Older Adults.

PubMed

Lee, Ahreum; Ryu, Hokyoung; Kim, Jae-Kwan; Jeong, Eunju

2018-04-11

Older adults are known to have lesser cognitive control capability and greater susceptibility to distraction than young adults. Previous studies have reported age-related problems in selective attention and inhibitory control, yielding mixed results depending on modality and context in which stimuli and tasks were presented. The purpose of the study was to empirically demonstrate a modality-specific loss of inhibitory control in processing audio-visual information with ageing. A group of 30 young adults (mean age = 25.23, Standar Desviation (SD) = 1.86) and 22 older adults (mean age = 55.91, SD = 4.92) performed the audio-visual contour identification task (AV-CIT). We compared performance of visual/auditory identification (Uni-V, Uni-A) with that of visual/auditory identification in the presence of distraction in counterpart modality (Multi-V, Multi-A). The findings showed a modality-specific effect on inhibitory control. Uni-V performance was significantly better than Multi-V, indicating that auditory distraction significantly hampered visual target identification. However, Multi-A performance was significantly enhanced compared to Uni-A, indicating that auditory target performance was significantly enhanced by visual distraction. Additional analysis showed an age-specific effect on enhancement between Uni-A and Multi-A depending on the level of visual inhibition. Together, our findings indicated that the loss of visual inhibitory control was beneficial for the auditory target identification presented in a multimodal context in older adults. A likely multisensory information processing strategy in the older adults was further discussed in relation to aged cognition.

Are numbers, size and brightness equally efficient in orienting visual attention? Evidence from an eye-tracking study.

PubMed

Bulf, Hermann; Macchi Cassia, Viola; de Hevia, Maria Dolores

2014-01-01

A number of studies have shown strong relations between numbers and oriented spatial codes. For example, perceiving numbers causes spatial shifts of attention depending upon numbers' magnitude, in a way suggestive of a spatially oriented, mental representation of numbers. Here, we investigated whether this phenomenon extends to non-symbolic numbers, as well as to the processing of the continuous dimensions of size and brightness, exploring whether different quantitative dimensions are equally mapped onto space. After a numerical (symbolic Arabic digits or non-symbolic arrays of dots; Experiment 1) or a non-numerical cue (shapes of different size or brightness level; Experiment 2) was presented, participants' saccadic response to a target that could appear either on the left or the right side of the screen was registered using an automated eye-tracker system. Experiment 1 showed that, both in the case of Arabic digits and dot arrays, right targets were detected faster when preceded by large numbers, and left targets were detected faster when preceded by small numbers. Participants in Experiment 2 were faster at detecting right targets when cued by large-sized shapes and left targets when cued by small-sized shapes, whereas brightness cues did not modulate the detection of peripheral targets. These findings indicate that looking at a symbolic or a non-symbolic number induces attentional shifts to a peripheral region of space that is congruent with the numbers' relative position on a mental number line, and that a similar shift in visual attention is induced by looking at shapes of different size. More specifically, results suggest that, while the dimensions of number and size spontaneously map onto an oriented space, the dimension of brightness seems to be independent at a certain level of magnitude elaboration from the dimensions of spatial extent and number, indicating that not all continuous dimensions are equally mapped onto space.

Electronic monitoring of occlusion treatment for amblyopia in patients aged 7 to 16 years.

PubMed

Fronius, Maria; Bachert, Iris; Lüchtenberg, Marc

2009-10-01

Age limits for the prescription of amblyopia treatment have been debated and challenged recently, due to results of studies from ophthalmology and the neurosciences. Lack of knowledge about compliance with prescribed treatment is still a major factor for the uncertainty about the amount of plasticity in the visual system of older children and adolescents. The development of devices for the electronic recording of patching (Occlusion Dose Monitor, ODM) has allowed the collection of objective data about daily occlusion. In a prospective study, occlusion dose rates were recorded continuously during 4 months by means of the ODM developed in the Netherlands [1] in nine amblyopic patients between 7 and 16 years of age who were prescribed between 5 and 7 hours of daily patching. Visual acuity was assessed every 3 to 6 weeks. The electronic monitoring showed objective occlusion between 2 and 6.25 hours/day (mean 4.61 h/d) during the first month and 0 to 6.5 hours/day (mean 3.47 h/d) during the following 3 months of treatment. The total acuity gain in the amblyopic eye amounted to between -0.1 and 0.4 log units (mean 0.19) for crowded optotypes. Differences to initial acuities were statistically significant. The calculated average dose-response relationship (cumulated hours occlusion*0.1/acuity gain) for 4 months of occlusion was 234 hours of occlusion per 0.1 log unit of acuity gain. This study presents for the first time objective treatment and dose response data in amblyopic patients beyond the "classical" treatment age. Electronic monitoring of occlusion and considerable amounts of patching were shown to be feasible. The acuity results indicate that there is a potential for improvement, yet treatment seemed to be less efficient than shown by previous studies in younger patients. Continuation of this research may advance the discussion about age-dependent evidence-based amblyopia treatment, about preschool screening for amblyopia and about plasticity of the visual system.

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

PubMed

Souza, Alessandra S; Oberauer, Klaus

2017-10-01

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

Distinct neural markers of TVA-based visual processing speed and short-term storage capacity parameters.

PubMed

Wiegand, Iris; Töllner, Thomas; Habekost, Thomas; Dyrholm, Mads; Müller, Hermann J; Finke, Kathrin

2014-08-01

An individual's visual attentional capacity is characterized by 2 central processing resources, visual perceptual processing speed and visual short-term memory (vSTM) storage capacity. Based on Bundesen's theory of visual attention (TVA), independent estimates of these parameters can be obtained from mathematical modeling of performance in a whole report task. The framework's neural interpretation (NTVA) further suggests distinct brain mechanisms underlying these 2 functions. Using an interindividual difference approach, the present study was designed to establish the respective ERP correlates of both parameters. Participants with higher compared to participants with lower processing speed were found to show significantly reduced visual N1 responses, indicative of higher efficiency in early visual processing. By contrast, for participants with higher relative to lower vSTM storage capacity, contralateral delay activity over visual areas was enhanced while overall nonlateralized delay activity was reduced, indicating that holding (the maximum number of) items in vSTM relies on topographically specific sustained activation within the visual system. Taken together, our findings show that the 2 main aspects of visual attentional capacity are reflected in separable neurophysiological markers, validating a central assumption of NTVA. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Don’t Assume Deaf Students are Visual Learners

PubMed Central

Marschark, Marc; Paivio, Allan; Spencer, Linda J.; Durkin, Andreana; Borgna, Georgianna; Convertino, Carol; Machmer, Elizabeth

2016-01-01

In the education of deaf learners, from primary school to postsecondary settings, it frequently is suggested that deaf students are visual learners. That assumption appears to be based on the visual nature of signed languages—used by some but not all deaf individuals—and the fact that with greater hearing losses, deaf students will rely relatively more on vision than audition. However, the questions of whether individuals with hearing loss are more likely to be visual learners than verbal learners or more likely than hearing peers to be visual learners have not been empirically explored. Several recent studies, in fact, have indicated that hearing learners typically perform as well or better than deaf learners on a variety of visual-spatial tasks. The present study used two standardized instruments to examine learning styles among college deaf students who primarily rely on sign language or spoken language and their hearing peers. The visual-verbal dimension was of particular interest. Consistent with recent indirect findings, results indicated that deaf students are no more likely than hearing students to be visual learners and are no stronger in their visual skills and habits than their verbal skills and habits, nor are deaf students’ visual orientations associated with sign language skills. The results clearly have specific implications for the educating of deaf learners. PMID:28344430

The Role of Spirituality in Coping with Visual Impairment

ERIC Educational Resources Information Center

Yampolsky, Maya A.; Wittich, Walter; Webb, Gail; Overbury, Olga

2008-01-01

Spirituality and coping behaviors were measured in 85 individuals with visual impairments aged 23 to 97. A regression analysis indicated that the religious well-being subscale of the Spiritual Well-Being Scale is a significant predictor of adaptive coping behaviors, indicating that higher religious well-being facilitates adaptive coping. (Contains…

Visualizing Interaction Patterns in Online Discussions and Indices of Cognitive Presence

ERIC Educational Resources Information Center

Gibbs, William J.

2006-01-01

This paper discusses Mapping Temporal Relations of Discussions Software (MTRDS), a Web-based application that visually represents the temporal relations of online discussions. MTRDS was used to observe interaction characteristics of three online discussions. In addition, the research employed the Practical Inquiry Model to identify indices of…

Specific Instructions Are Important for Continuous Bimanual Drumming in Adults with Down Syndrome

ERIC Educational Resources Information Center

Ringenbach, Shannon D.; Allen, Heather; Chung, Susan; Jung, Michelle L.

2006-01-01

The present study examined continuous and discrete bimanual drumming in response to different instructions in 10 adults with Down syndrome, 10 mental age-matched and 10 chronological age-matched groups. For continuous drumming, participants hit two drums with both hands at the same time following verbal (e.g., "up" and "down"), visual (e.g., video…

Continuous and Noninvasive Recording of Cardiovascular Parameters with the Finapres Finger Cuff Enhances Undergraduate Student Understanding of Physiology

ERIC Educational Resources Information Center

Hodgson, Yvonne; Choate, Julia

2012-01-01

The Finapres finger cuff recording system provides continuous calculations of beat-to-beat variations in cardiac output (CO), total peripheral resistance, heart rate (HR), and blood pressure (BP). This system is unique in that it allows experimental subjects to immediately, continuously, and noninvasively visualize changes in CO at rest and during…

The impact of continuity editing in narrative film on event segmentation.

PubMed

Magliano, Joseph P; Zacks, Jeffrey M

2011-01-01

Filmmakers use continuity editing to engender a sense of situational continuity or discontinuity at editing boundaries. The goal of this study was to assess the impact of continuity editing on how people perceive the structure of events in a narrative film and to identify brain networks that are associated with the processing of different types of continuity editing boundaries. Participants viewed a commercially produced film and segmented it into meaningful events, while brain activity was recorded with functional magnetic resonance imaging (MRI). We identified three degrees of continuity that can occur at editing locations: edits that are continuous in space, time, and action; edits that are discontinuous in space or time but continuous in action; and edits that are discontinuous in action as well as space or time. Discontinuities in action had the biggest impact on behavioral event segmentation, and discontinuities in space and time had minor effects. Edits were associated with large transient increases in early visual areas. Spatial-temporal changes and action changes produced strikingly different patterns of transient change, and they provided evidence that specialized mechanisms in higher order perceptual processing regions are engaged to maintain continuity of action in the face of spatiotemporal discontinuities. These results suggest that commercial film editing is shaped to support the comprehension of meaningful events that bridge breaks in low-level visual continuity, and even breaks in continuity of spatial and temporal location. Copyright © 2011 Cognitive Science Society, Inc.

The continuous Wagon Wheel Illusion depends on, but is not identical to neuronal adaptation.

PubMed

VanRullen, Rufin

2007-07-01

The occurrence of perceived reversed motion while observers view a continuous, periodically moving stimulus (a bistable phenomenon coined the "continuous Wagon Wheel Illusion" or "c-WWI") has been taken as evidence that some aspects of motion perception rely on discrete sampling of visual information. Alternative accounts rely on the possibility of a motion aftereffect that may become visible even while the adapting stimulus is present. Here I show that motion adaptation might be necessary, but is not sufficient to explain the illusion. When local adaptation is prevented by slowly drifting the moving wheel across the retina, the c-WWI illusion tends to decrease, as do other bistable percepts (e.g. binocular rivalry). However, the strength of the c-WWI and that of adaptation (as measured by either the static or flicker motion aftereffects) are not directly related: although the c-WWI decreases with increasing eccentricity, the aftereffects actually intensify concurrently. A similar dissociation can be induced by manipulating stimulus contrast. This indicates that the c-WWI may be enabled by, but is not equivalent to, local motion adaptation - and that other factors such as discrete sampling may be involved in its generation.

Design of intelligent proximity detection zones to prevent striking and pinning fatalities around continuous mining machines.

PubMed

Bissert, P T; Carr, J L; DuCarme, J P; Smith, A K

2016-01-01

The continuous mining machine is a key piece of equipment used in underground coal mining operations. Over the past several decades these machines have been involved in a number of mine worker fatalities. Proximity detection systems have been developed to avert hazards associated with operating continuous mining machines. Incorporating intelligent design into proximity detection systems allows workers greater freedom to position themselves to see visual cues or avoid other hazards such as haulage equipment or unsupported roof or ribs. However, intelligent systems must be as safe as conventional proximity detection systems. An evaluation of the 39 fatal accidents for which the Mine Safety and Health Administration has published fatality investigation reports was conducted to determine whether the accident may have been prevented by conventional or intelligent proximity. Multiple zone configurations for the intelligent systems were studied to determine how system performance might be affected by the zone configuration. Researchers found that 32 of the 39 fatalities, or 82 percent, may have been prevented by both conventional and intelligent proximity systems. These results indicate that, by properly configuring the zones of an intelligent proximity detection system, equivalent protection to a conventional system is possible.

Computer Vision Syndrome for Non-Native Speaking Students: What Are the Problems with Online Reading?

ERIC Educational Resources Information Center

Tseng, Min-chen

2014-01-01

This study investigated the online reading performances and the level of visual fatigue from the perspectives of non-native speaking students (NNSs). Reading on a computer screen is more visually more demanding than reading printed text. Online reading requires frequent saccadic eye movements and imposes continuous focusing and alignment demand.…

Using Superheroes to Visually and Critically Analyze Comics, Stereotypes, and Society

ERIC Educational Resources Information Center

Cook, Mike P.; Frey, Ryle

2017-01-01

The purpose of this article is to provide teachers and students useful methods for utilizing the power of comic books as literacy sponsors in ELA classrooms. Given the continued boom in the popularity of comics in popular culture, this provides a relevant way to introduce students to visual and critical analysis. Engaging in meaningful analysis of…

Linear utility corridors—a simulated visual field trip

Treesearch

Robert W. Ross Jr.

1979-01-01

With the increase in various utility corridors continuing to find their way across the American landscape, more and more people are becoming concerned about their ecological as well as visual impact. This paper examines "linear utility corridors" in terms of those that transport energy and those that transport fuels, their various components, and the types of...

Discrete Resource Allocation in Visual Working Memory

ERIC Educational Resources Information Center

Barton, Brian; Ester, Edward F.; Awh, Edward

2009-01-01

Are resources in visual working memory allocated in a continuous or a discrete fashion? On one hand, flexible resource models suggest that capacity is determined by a central resource pool that can be flexibly divided such that items of greater complexity receive a larger share of resources. On the other hand, if capacity in working memory is…

Synthetic Flight Training System Study

DTIC Science & Technology

1983-12-23

Distribution unlimited IC. SUPPLEMENTARY NOTiS - 19. KEY WORDS (Continue on reveree side if necoeeary and Identify by block nunber) Visual Systems Computer ...platforms, instructional features, computer hardware and software, student stations, etc. DOR 1473 EDITON OF INMOV6S ISOSOLETE Unclassified SECURITY... Computational Systems .................................... 4-I I 4.5.3 Visual Processing Systems .......................... 4-13 4.5.4 Instructor Stations

Privileged Detection of Conspecifics: Evidence from Inversion Effects during Continuous Flash Suppression

ERIC Educational Resources Information Center

Stein, Timo; Sterzer, Philipp; Peelen, Marius V.

2012-01-01

The rapid visual detection of other people in our environment is an important first step in social cognition. Here we provide evidence for selective sensitivity of the human visual system to upright depictions of conspecifics. In a series of seven experiments, we assessed the impact of stimulus inversion on the detection of person silhouettes,…

Window of visibility - A psychophysical theory of fidelity in time-sampled visual motion displays

NASA Technical Reports Server (NTRS)

Watson, A. B.; Ahumada, A. J., Jr.; Farrell, J. E.

1986-01-01

A film of an object in motion presents on the screen a sequence of static views, while the human observer sees the object moving smoothly across the screen. Questions related to the perceptual identity of continuous and stroboscopic displays are examined. Time-sampled moving images are considered along with the contrast distribution of continuous motion, the contrast distribution of stroboscopic motion, the frequency spectrum of continuous motion, the frequency spectrum of stroboscopic motion, the approximation of the limits of human visual sensitivity to spatial and temporal frequencies by a window of visibility, the critical sampling frequency, the contrast distribution of staircase motion and the frequency spectrum of this motion, and the spatial dependence of the critical sampling frequency. Attention is given to apparent motion, models of motion, image recording, and computer-generated imagery.

Visual examination apparatus

NASA Technical Reports Server (NTRS)

Haines, R. F.; Fitzgerald, J. W.; Rositano, S. A. (Inventor)

1973-01-01

An automated visual examination apparatus for measuring visual sensitivity and mapping blind spot location is described. The apparatus includes a projection system for displaying to a patient a series of visual stimuli, a response switch enabling him to indicate his reaction to the stimuli, and a recording system responsive to both the visual stimuli per se and the patient's response. The recording system provides a correlated permanent record of both stimuli and response from which a substantive and readily apparent visual evaluation can be made.

An Expanded Framework for Biomolecular Visualization in the Classroom: Learning Goals and Competencies

ERIC Educational Resources Information Center

Dries, Daniel R.; Dean, Diane M.; Listenberger, Laura L.; Novak, Walter R. P.; Franzen, Margaret A.; Craig, Paul A.

2017-01-01

A thorough understanding of the molecular biosciences requires the ability to visualize and manipulate molecules in order to interpret results or to generate hypotheses. While many instructors in biochemistry and molecular biology use visual representations, few indicate that they explicitly teach visual literacy. One reason is the need for a list…

The Effect of Visual Threat on Spatial Attention to Touch

ERIC Educational Resources Information Center

Poliakoff, Ellen; Miles, Eleanor; Li, Xinying; Blanchette, Isabelle

2007-01-01

Viewing a threatening stimulus can bias visual attention toward that location. Such effects have typically been investigated only in the visual modality, despite the fact that many threatening stimuli are most dangerous when close to or in contact with the body. Recent multisensory research indicates that a neutral visual stimulus, such as a light…

Helping Children with Visual Impairment Develop Humour: A Review of the Literature

ERIC Educational Resources Information Center

Pagliano, Paul J.; Zambone, Alana M.; Kelley, Pat

2007-01-01

Humor is a highly regarded attribute and often forms the basis of childhood friendships. As much humor is visual, children with visual impairment are particularly vulnerable to missing out on this type of development. Recent research indicates that children can be taught to develop their sense of humor. Therefore, children with visual impairment…

[Change settings for visual analyzer of child users of mobile communication: longitudinal study].

PubMed

Khorseva, N I; Grigor'ev, Iu G; Gorbunova, N V

2014-01-01

The paper represents theresults of longitudinal monitoring of the changes in the parameters of simple visual-motor reaction, the visual acuity and the rate of the visual discrimination in the child users of mobile communication, which indicate the multivariability of the possible effects of radiation from mobile phones on the auditory system of children.

Continuous Personal Improvement.

ERIC Educational Resources Information Center

Emiliani, M. L.

1998-01-01

Suggests that continuous improvement tools used in the workplace can be applied to self-improvement. Explains the use of such techniques as one-piece flow, kanban, visual controls, and total productive maintenance. Points out misapplications of these tools and describes the use of fishbone diagrams to diagnose problems. (SK)

75 FR 34486 - Petitions for Modification

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-17

... while continuously monitoring for methane levels. Immediately prior to the use of the non-permissible equipment, the mine atmosphere will be tested for methane within 6 inches, and would be continuously monitored with an approved instrument capable of providing both visual and audible alarms. Methane levels...

40 CFR 63.7740 - What are my monitoring requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Iron and Steel Foundries Continuous...) Inspect fans for wear, material buildup, and corrosion through quarterly visual inspections, vibration... more automated conveyor and pallet cooling lines and automated shakeout lines at a new iron and steel...

40 CFR 63.7830 - What are my monitoring requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... equivalent means. (vi) Make monthly visual checks of bag tension on reverse air and shaker-type baghouses to...? 63.7830 Section 63.7830 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

40 CFR 63.7830 - What are my monitoring requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... equivalent means. (vi) Make monthly visual checks of bag tension on reverse air and shaker-type baghouses to...? 63.7830 Section 63.7830 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...

Neural Pathways Conveying Novisual Information to the Visual Cortex

PubMed Central

2013-01-01

The visual cortex has been traditionally considered as a stimulus-driven, unimodal system with a hierarchical organization. However, recent animal and human studies have shown that the visual cortex responds to non-visual stimuli, especially in individuals with visual deprivation congenitally, indicating the supramodal nature of the functional representation in the visual cortex. To understand the neural substrates of the cross-modal processing of the non-visual signals in the visual cortex, we firstly showed the supramodal nature of the visual cortex. We then reviewed how the nonvisual signals reach the visual cortex. Moreover, we discussed if these non-visual pathways are reshaped by early visual deprivation. Finally, the open question about the nature (stimulus-driven or top-down) of non-visual signals is also discussed. PMID:23840972

Processing of visual semantic information to concrete words: temporal dynamics and neural mechanisms indicated by event-related brain potentials( ).

PubMed

van Schie, Hein T; Wijers, Albertus A; Mars, Rogier B; Benjamins, Jeroen S; Stowe, Laurie A

2005-05-01

Event-related brain potentials were used to study the retrieval of visual semantic information to concrete words, and to investigate possible structural overlap between visual object working memory and concreteness effects in word processing. Subjects performed an object working memory task that involved 5 s retention of simple 4-angled polygons (load 1), complex 10-angled polygons (load 2), and a no-load baseline condition. During the polygon retention interval subjects were presented with a lexical decision task to auditory presented concrete (imageable) and abstract (nonimageable) words, and pseudowords. ERP results are consistent with the use of object working memory for the visualisation of concrete words. Our data indicate a two-step processing model of visual semantics in which visual descriptive information of concrete words is first encoded in semantic memory (indicated by an anterior N400 and posterior occipital positivity), and is subsequently visualised via the network for object working memory (reflected by a left frontal positive slow wave and a bilateral occipital slow wave negativity). Results are discussed in the light of contemporary models of semantic memory.

Semantic-based crossmodal processing during visual suppression.

PubMed

Cox, Dustin; Hong, Sang Wook

2015-01-01

To reveal the mechanisms underpinning the influence of auditory input on visual awareness, we examine, (1) whether purely semantic-based multisensory integration facilitates the access to visual awareness for familiar visual events, and (2) whether crossmodal semantic priming is the mechanism responsible for the semantic auditory influence on visual awareness. Using continuous flash suppression, we rendered dynamic and familiar visual events (e.g., a video clip of an approaching train) inaccessible to visual awareness. We manipulated the semantic auditory context of the videos by concurrently pairing them with a semantically matching soundtrack (congruent audiovisual condition), a semantically non-matching soundtrack (incongruent audiovisual condition), or with no soundtrack (neutral video-only condition). We found that participants identified the suppressed visual events significantly faster (an earlier breakup of suppression) in the congruent audiovisual condition compared to the incongruent audiovisual condition and video-only condition. However, this facilitatory influence of semantic auditory input was only observed when audiovisual stimulation co-occurred. Our results suggest that the enhanced visual processing with a semantically congruent auditory input occurs due to audiovisual crossmodal processing rather than semantic priming, which may occur even when visual information is not available to visual awareness.

Parallel perceptual enhancement and hierarchic relevance evaluation in an audio-visual conjunction task.

PubMed

Potts, Geoffrey F; Wood, Susan M; Kothmann, Delia; Martin, Laura E

2008-10-21

Attention directs limited-capacity information processing resources to a subset of available perceptual representations. The mechanisms by which attention selects task-relevant representations for preferential processing are not fully known. Triesman and Gelade's [Triesman, A., Gelade, G., 1980. A feature integration theory of attention. Cognit. Psychol. 12, 97-136.] influential attention model posits that simple features are processed preattentively, in parallel, but that attention is required to serially conjoin multiple features into an object representation. Event-related potentials have provided evidence for this model showing parallel processing of perceptual features in the posterior Selection Negativity (SN) and serial, hierarchic processing of feature conjunctions in the Frontal Selection Positivity (FSP). Most prior studies have been done on conjunctions within one sensory modality while many real-world objects have multimodal features. It is not known if the same neural systems of posterior parallel processing of simple features and frontal serial processing of feature conjunctions seen within a sensory modality also operate on conjunctions between modalities. The current study used ERPs and simultaneously presented auditory and visual stimuli in three task conditions: Attend Auditory (auditory feature determines the target, visual features are irrelevant), Attend Visual (visual features relevant, auditory irrelevant), and Attend Conjunction (target defined by the co-occurrence of an auditory and a visual feature). In the Attend Conjunction condition when the auditory but not the visual feature was a target there was an SN over auditory cortex, when the visual but not auditory stimulus was a target there was an SN over visual cortex, and when both auditory and visual stimuli were targets (i.e. conjunction target) there were SNs over both auditory and visual cortex, indicating parallel processing of the simple features within each modality. In contrast, an FSP was present when either the visual only or both auditory and visual features were targets, but not when only the auditory stimulus was a target, indicating that the conjunction target determination was evaluated serially and hierarchically with visual information taking precedence. This indicates that the detection of a target defined by audio-visual conjunction is achieved via the same mechanism as within a single perceptual modality, through separate, parallel processing of the auditory and visual features and serial processing of the feature conjunction elements, rather than by evaluation of a fused multimodal percept.

Oculomotor Reflexes as a Test of Visual Dysfunctions in Cognitively Impaired Observers

DTIC Science & Technology

2013-09-01

right. Gaze horizontal position is plotted along the y-axis. The red bar indicates a visual nystagmus event detected by the filter. (d) A mild curse word...experimental conditions were chosen to simulate testing cognitively impaired observers. Reflex Stimulus Functions Visual Nystagmus luminance grating low-level...developed a new stimulus for visual nystagmus to 8 test visual motion processing in the presence of incoherent motion noise. The drifting equiluminant

[Visual field progression in glaucoma: cluster analysis].

PubMed

Bresson-Dumont, H; Hatton, J; Foucher, J; Fonteneau, M

2012-11-01

Visual field progression analysis is one of the key points in glaucoma monitoring, but distinction between true progression and random fluctuation is sometimes difficult. There are several different algorithms but no real consensus for detecting visual field progression. The trend analysis of global indices (MD, sLV) may miss localized deficits or be affected by media opacities. Conversely, point-by-point analysis makes progression difficult to differentiate from physiological variability, particularly when the sensitivity of a point is already low. The goal of our study was to analyse visual field progression with the EyeSuite™ Octopus Perimetry Clusters algorithm in patients with no significant changes in global indices or worsening of the analysis of pointwise linear regression. We analyzed the visual fields of 162 eyes (100 patients - 58 women, 42 men, average age 66.8 ± 10.91) with ocular hypertension or glaucoma. For inclusion, at least six reliable visual fields per eye were required, and the trend analysis (EyeSuite™ Perimetry) of visual field global indices (MD and SLV), could show no significant progression. The analysis of changes in cluster mode was then performed. In a second step, eyes with statistically significant worsening of at least one of their clusters were analyzed point-by-point with the Octopus Field Analysis (OFA). Fifty four eyes (33.33%) had a significant worsening in some clusters, while their global indices remained stable over time. In this group of patients, more advanced glaucoma was present than in stable group (MD 6.41 dB vs. 2.87); 64.82% (35/54) of those eyes in which the clusters progressed, however, had no statistically significant change in the trend analysis by pointwise linear regression. Most software algorithms for analyzing visual field progression are essentially trend analyses of global indices, or point-by-point linear regression. This study shows the potential role of analysis by clusters trend. However, for best results, it is preferable to compare the analyses of several tests in combination with morphologic exam. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Three-dimensional organization of nascent rod outer segment disk membranes.

PubMed

Volland, Stefanie; Hughes, Louise C; Kong, Christina; Burgess, Barry L; Linberg, Kenneth A; Luna, Gabriel; Zhou, Z Hong; Fisher, Steven K; Williams, David S

2015-12-01

The vertebrate photoreceptor cell contains an elaborate cilium that includes a stack of phototransductive membrane disks. The disk membranes are continually renewed, but how new disks are formed remains poorly understood. Here we used electron microscope tomography to obtain 3D visualization of the nascent disks of rod photoreceptors in three mammalian species, to gain insight into the process of disk morphogenesis. We observed that nascent disks are invariably continuous with the ciliary plasma membrane, although, owing to partial enclosure, they can appear to be internal in 2D profiles. Tomographic analyses of the basal-most region of the outer segment show changes in shape of the ciliary plasma membrane indicating an invagination, which is likely a first step in disk formation. The invagination flattens to create the proximal surface of an evaginating lamella, as well as membrane protrusions that extend between adjacent lamellae, thereby initiating a disk rim. Immediately distal to this initiation site, lamellae of increasing diameter are evident, indicating growth outward from the cilium. In agreement with a previous model, our data indicate that mature disks are formed once lamellae reach full diameter, and the growth of a rim encloses the space between adjacent surfaces of two lamellae. This study provides 3D data of nascent and mature rod photoreceptor disk membranes at unprecedented z-axis depth and resolution, and provides a basis for addressing fundamental questions, ranging from protein sorting in the photoreceptor cilium to photoreceptor electrophysiology.

High visual resolution matters in audiovisual speech perception, but only for some.

PubMed

Alsius, Agnès; Wayne, Rachel V; Paré, Martin; Munhall, Kevin G

2016-07-01

The basis for individual differences in the degree to which visual speech input enhances comprehension of acoustically degraded speech is largely unknown. Previous research indicates that fine facial detail is not critical for visual enhancement when auditory information is available; however, these studies did not examine individual differences in ability to make use of fine facial detail in relation to audiovisual speech perception ability. Here, we compare participants based on their ability to benefit from visual speech information in the presence of an auditory signal degraded with noise, modulating the resolution of the visual signal through low-pass spatial frequency filtering and monitoring gaze behavior. Participants who benefited most from the addition of visual information (high visual gain) were more adversely affected by the removal of high spatial frequency information, compared to participants with low visual gain, for materials with both poor and rich contextual cues (i.e., words and sentences, respectively). Differences as a function of gaze behavior between participants with the highest and lowest visual gains were observed only for words, with participants with the highest visual gain fixating longer on the mouth region. Our results indicate that the individual variance in audiovisual speech in noise performance can be accounted for, in part, by better use of fine facial detail information extracted from the visual signal and increased fixation on mouth regions for short stimuli. Thus, for some, audiovisual speech perception may suffer when the visual input (in addition to the auditory signal) is less than perfect.

The eye amputated - consequences of eye amputation with emphasis on clinical aspects, phantom eye syndrome and quality of life.

PubMed

Rasmussen, Marie Louise Roed

2010-12-01

In this thesis the term eye amputation (EA) covers the removing of an eye by: evisceration, enucleation and exenteration. Amputation of an eye is most frequently the end-stage in a complicated disease, or the primary treatment in trauma and neoplasm. In 2010 the literature is extensive due to knowledge about types of surgery, implants and surgical technique. However, not much is known about the time past surgery. To identify the number of EA, the causative diagnosis and the indication for surgical removal of the eye, the chosen surgical technique and to evaluate a possible change in surgical technique in Denmark from 1996 until 2003 (paper I); To describe the phantom eye syndrome and its prevalence of visual hallucinations, phantom pain and phantom sensations (paper II); To characterise the quality of phantom eye pain, including its intensity and frequency among EA patients. We attempted to identify patients with increased risk of developing pain after EA and investigated if preoperative pain is a risk factor for a later development of phantom pain (paper III); In addition we wanted to investigate the health related quality of life, perceived stress, self rated health, job separation due to illness or disability and socio-economic position of the EA in comparison with the general Danish population (paper IV). Records on 431 EA patients, clinical ophthalmological examination and an interview study of 173 EA patients and a questionnaire answered by 120 EA patients. The most frequent indications for EA in Denmark were painful blind eye (37%) and neoplasm (34%). During the study period 1996-2003, the annual number of eye amputations was stable, but an increase in bulbar eviscerations was noticed. Orbital implants were used with an increasing tendency until 2003. The Phantom eye syndrome is frequent among EA patients. Visual hallucinations were described by 42% of the patients. The content were mainly elementary visual hallucinations, with white or colored light as a continuous sharp light or as moving dots. The most frequent triggers were darkness, closing of the eyes, fatigue and psychological stress. Fifty-four percent of the patients had visual hallucinations more than once a week. Ten patients were so visually disturbed that it interfered with their daily life. Approximately 23% of all EA experience phantom pain for several years after the surgery. Phantom pain was reported to be of three different qualities: (i) cutting, penetrating, gnawing or oppressive (n=19); (ii) radiating, zapping or shooting (n=8); (iii) superficial burning or stinging (n=5); or a mixture of these different pain qualities (n=7). The median intensity on a visual analogue scale, ranging from 0 to 100, was 36 [range: 1-89]. One-third of the patients experienced phantom pain every day. Chilliness, windy weather and psychological stress/fatigue were the most commonly reported triggers for pain. Factors associated with phantom pain were: ophthalmic pain before EA, the presence of implant and a patient reported high degree of conjunctival secretion. A common reason for EA is the presence of a painful blind eye. However, one third of these patients continue to have pain after the EA. Phantom sensations were present in 2% of the patients. The impact of an eye amputation is considerable. EA patients have poorer health related quality of life, poorer self-rated health and more perceived stress than does the general population. The largest differences in health related quality of life between the EA patients and the general population were related to role limitations due to emotional problems and mental health. Patients with the indication painful blind eye are having lower scores in all aspects of health related quality of life and perceived stress than patients with the indication neoplasm and trauma. The percentage of eye amputated which is divorced or separated was twice as high as in the general population. Furthermore, 25% retired or changed to part-time jobs due to eye disease and 39.5% stopped participating in leisure activities due to their EAs. © 2010 The Author. Acta Ophthalmologica © 2010 Acta Ophthalmologica Scandinavica Foundation.

40 CFR 63.163 - Standards: Pumps in light liquid service.

Code of Federal Regulations, 2010 CFR

2010-07-01

... handling polymerizing monomers; (B) 2,000 parts per million or greater for pumps in food/medical service... visual inspection each calendar week for indications of liquids dripping from the pump seal. If there are... pump is checked by visual inspection each calendar week for indications of liquids dripping from the...

Visual indication of enviromental humidity by using poly(ionic liquid) photonic crystals.

PubMed

Huang, Jing; Tao, Cheng-an; An, Qi; Lin, Changxu; Li, Xuesong; Xu, Dan; Wu, Yiguang; Li, Xiaogang; Shen, Dezhong; Li, Guangtao

2010-06-21

The combination of poly (ionic liquid) and photonic structure affords a new class of self-reporting humidity sensory materials with excellent reversibility, which are able to rapidly, sensitively and visually indicate environmental humidity with colour change from blue to green, orange, and red, covering the whole visible range.

The Ways of the Hand: A Study of Hand Function among Blind, Visually Impaired and Visually Impaired Multi-Handicapped Children and Adolescents.

ERIC Educational Resources Information Center

Rogow, Sally M.

1987-01-01

The manual development of 148 blind, visually impaired, and visually impaired multi-handicapped students, aged 3-19, was studied. Results indicated a significant relationship between object manipulation and speech, and an inverse relationship between object manipulation and stereotypic hand mannerisms. Optimal development of manual functions and…

The Effect of Visualized Instruction and Varied Rehearsal and Evaluation Strategies (Verbal and Visual) in Facilitating Students' Long-Term Retention on Tests Measuring Different Instructional Objectives.

ERIC Educational Resources Information Center

Dwyer, Francis M.

1985-01-01

This study investigated effects of rehearsal strategies and immediate test formats on delayed retention and effectiveness of visualization on material acquisition and retrieval. Findings indicate different rehearsal methods have different effects in facilitating delayed retention. Information acquisition is facilitated by visualization, although…

Functional Literacy for Students with Visual Impairments and Significant Cognitive Disabilities: The Perspective of Teachers of Students with Visual Impairments

ERIC Educational Resources Information Center

Zebehazy, Kim T.

2014-01-01

This study reports opinions and practices of teachers of students with visual impairments (TSVIs) in 34 states regarding functional literacy for students with visual impairments (VIs) and significant cognitive disabilities (SCDs). The survey asked TSVIs to select a definition of functional literacy, indicate agreement with a series of literacy…

Phasic alertness cues modulate visual processing speed in healthy aging.

PubMed

Haupt, Marleen; Sorg, Christian; Napiórkowski, Natan; Finke, Kathrin

2018-05-31

Warning signals temporarily increase the rate of visual information in younger participants and thus optimize perception in critical situations. It is unclear whether such important preparatory processes are preserved in healthy aging. We parametrically assessed the effects of auditory alertness cues on visual processing speed and their time course using a whole report paradigm based on the computational Theory of Visual Attention. We replicated prior findings of significant alerting benefits in younger adults. In conditions with short cue-target onset asynchronies, this effect was baseline-dependent. As younger participants with high baseline speed did not show a profit, an inverted U-shaped function of phasic alerting and visual processing speed was implied. Older adults also showed a significant cue-induced benefit. Bayesian analyses indicated that the cueing benefit on visual processing speed was comparably strong across age groups. Our results indicate that in aging individuals, comparable to younger ones, perception is active and increased expectancy of the appearance of a relevant stimulus can increase the rate of visual information uptake. Copyright © 2018 Elsevier Inc. All rights reserved.

Association of Chronic Subjective Tinnitus with Neuro- Cognitive Performance.

PubMed

Gudwani, Sunita; Munjal, Sanjay K; Panda, Naresh K; Kohli, Adarsh

2017-12-01

Chronic subjective tinnitus is associated with cognitive disruptions affecting perception, thinking, language, reasoning, problem solving, memory, visual tasks (reading) and attention. To evaluate existence of any association between tinnitus parameters and neuropsychological performance to explain cognitive processing. Study design was prospective, consisting 25 patients with idiopathic chronic subjective tinnitus and gave informed consent before planning their treatment. Neuropsychological profile included (i) performance on verbal information, comprehension, arithmetic and digit span; (ii) non-verbal performance for visual pattern completion analogies; (iii) memory performance for long-term, recent, delayed-recall, immediate-recall, verbal-retention, visualretention, visual recognition; (iv) reception, interpretation and execution for visual motor gestalt. Correlation between tinnitus onset duration/ loudness perception with neuropsychological profile was assessed by calculating Spearman's coefficient. Findings suggest that tinnitus may interfere with cognitive processing especially performance on digit span, verbal comprehension, mental balance, attention & concentration, immediate recall, visual recognition and visual-motor gestalt subtests. Negative correlation between neurocognitive tasks with tinnitus loudness and onset duration indicated their association. Positive correlation between tinnitus and visual-motor gestalt performance indicated the brain dysfunction. Tinnitus association with non-auditory processing of verbal, visual and visuo-spatial information suggested neuroplastic changes that need to be targeted in cognitive rehabilitation.

Mapping the structure of perceptual and visual-motor abilities in healthy young adults.

PubMed

Wang, Lingling; Krasich, Kristina; Bel-Bahar, Tarik; Hughes, Lauren; Mitroff, Stephen R; Appelbaum, L Gregory

2015-05-01

The ability to quickly detect and respond to visual stimuli in the environment is critical to many human activities. While such perceptual and visual-motor skills are important in a myriad of contexts, considerable variability exists between individuals in these abilities. To better understand the sources of this variability, we assessed perceptual and visual-motor skills in a large sample of 230 healthy individuals via the Nike SPARQ Sensory Station, and compared variability in their behavioral performance to demographic, state, sleep and consumption characteristics. Dimension reduction and regression analyses indicated three underlying factors: Visual-Motor Control, Visual Sensitivity, and Eye Quickness, which accounted for roughly half of the overall population variance in performance on this battery. Inter-individual variability in Visual-Motor Control was correlated with gender and circadian patters such that performance on this factor was better for males and for those who had been awake for a longer period of time before assessment. The current findings indicate that abilities involving coordinated hand movements in response to stimuli are subject to greater individual variability, while visual sensitivity and occulomotor control are largely stable across individuals. Copyright © 2015 Elsevier B.V. All rights reserved.

Personal factors influencing the visual reaction time of pedestrians to detect turn indicators in the presence of Daytime Running Lamps.

PubMed

Peña-García, Antonio; de Oña, Rocío; García, Pedro Antonio; de Oña, Juan

2016-12-01

Daytime running lamps (DRL) on vehicles have proven to be an effective measure to prevent accidents during the daytime, particularly when pedestrians and cyclists are involved. However, there are negative interactions of DRL with other functions in automotive lighting, such as delays in pedestrians' visual reaction time (VRT) when turn indicators are activated in the presence of DRL. These negative interactions need to be reduced. This work analyses the influence of variables inherent to pedestrians, such as height, gender and visual defects, on the VRT using a classification and regression tree as an exploratory analysis and a generalized linear model to validate the results. Some pedestrian characteristics, such as gender, alone or combined with the DRL colour, and visual defects, were found to have a statistically significant influence on VRT and, hence, on traffic safety. These results and conclusions concerning the interaction between pedestrians and vehicles are presented and discussed. Practitioner Summary: Visual interactions of vehicle daytime running lamps (DRL) with other functions in automotive lighting, such as turn indicators, have an important impact on a vehicle's conspicuity for pedestrians. Depending on several factors inherent to pedestrians, the visual reaction time (VRT) can be remarkably delayed, which has implications in traffic safety.

Ideal Positions: 3D Sonography, Medical Visuality, Popular Culture.

PubMed

Seiber, Tim

2016-03-01

As digital technologies are integrated into medical environments, they continue to transform the experience of contemporary health care. Importantly, medicine is increasingly visual. In the history of sonography, visibility has played an important role in accessing fetal bodies for diagnostic and entertainment purposes. With the advent of three-dimensional (3D) rendering, sonography presents the fetus visually as already a child. The aesthetics of this process and the resulting imagery, made possible in digital networks, discloses important changes in the relationship between technology and biology, reproductive health and political debates, and biotechnology and culture.

The Influence of Restricted Visual Feedback on Dribbling Performance in Youth Soccer Players.

PubMed

Fransen, Job; Lovell, Thomas W J; Bennett, Kyle J M; Deprez, Dieter; Deconinck, Frederik J A; Lenoir, Matthieu; Coutts, Aaron J

2017-04-01

The aim of the current study was to examine the influence of restricted visual feedback using stroboscopic eyewear on the dribbling performance of youth soccer players. Three dribble test conditions were used in a within-subjects design to measure the effect of restricted visual feedback on soccer dribbling performance in 189 youth soccer players (age: 10-18 y) classified as fast, average or slow dribblers. The results showed that limiting visual feedback increased dribble test times across all abilities. Furthermore, the largest performance decrement between stroboscopic and full vision conditions was in fast dribblers, showing that fast dribblers were most affected by reduced visual information. This may be due to a greater dependency on visual feedback at increased speeds, which may limit the ability to maintain continuous control of the ball. These findings may have important implications for the development of soccer dribbling ability.

Interobject grouping facilitates visual awareness.

PubMed

Stein, Timo; Kaiser, Daniel; Peelen, Marius V

2015-01-01

In organizing perception, the human visual system takes advantage of regularities in the visual input to perceptually group related image elements. Simple stimuli that can be perceptually grouped based on physical regularities, for example by forming an illusory contour, have a competitive advantage in entering visual awareness. Here, we show that regularities that arise from the relative positioning of complex, meaningful objects in the visual environment also modulate visual awareness. Using continuous flash suppression, we found that pairs of objects that were positioned according to real-world spatial regularities (e.g., a lamp above a table) accessed awareness more quickly than the same object pairs shown in irregular configurations (e.g., a table above a lamp). This advantage was specific to upright stimuli and abolished by stimulus inversion, meaning that it did not reflect physical stimulus confounds or the grouping of simple image elements. Thus, knowledge of the spatial configuration of objects in the environment shapes the contents of conscious perception.

Scientific Visualization in High Speed Network Environments

NASA Technical Reports Server (NTRS)

Vaziri, Arsi; Kutler, Paul (Technical Monitor)

1997-01-01

In several cases, new visualization techniques have vastly increased the researcher's ability to analyze and comprehend data. Similarly, the role of networks in providing an efficient supercomputing environment have become more critical and continue to grow at a faster rate than the increase in the processing capabilities of supercomputers. A close relationship between scientific visualization and high-speed networks in providing an important link to support efficient supercomputing is identified. The two technologies are driven by the increasing complexities and volume of supercomputer data. The interaction of scientific visualization and high-speed networks in a Computational Fluid Dynamics simulation/visualization environment are given. Current capabilities supported by high speed networks, supercomputers, and high-performance graphics workstations at the Numerical Aerodynamic Simulation Facility (NAS) at NASA Ames Research Center are described. Applied research in providing a supercomputer visualization environment to support future computational requirements are summarized.

Big data in medical informatics: improving education through visual analytics.

PubMed

Vaitsis, Christos; Nilsson, Gunnar; Zary, Nabil

2014-01-01

A continuous effort to improve healthcare education today is currently driven from the need to create competent health professionals able to meet healthcare demands. Limited research reporting how educational data manipulation can help in healthcare education improvement. The emerging research field of visual analytics has the advantage to combine big data analysis and manipulation techniques, information and knowledge representation, and human cognitive strength to perceive and recognise visual patterns. The aim of this study was therefore to explore novel ways of representing curriculum and educational data using visual analytics. Three approaches of visualization and representation of educational data were presented. Five competencies at undergraduate medical program level addressed in courses were identified to inaccurately correspond to higher education board competencies. Different visual representations seem to have a potential in impacting on the ability to perceive entities and connections in the curriculum data.

Measuring pilot workload in a motion base simulator. III - Synchronous secondary task

NASA Technical Reports Server (NTRS)

Kantowitz, Barry H.; Bortolussi, Michael R.; Hart, Sandra G.

1987-01-01

This experiment continues earlier research of Kantowitz et al. (1983) conducted in a GAT-1 motion-base trainer to evaluate choice-reaction secondary tasks as measures of pilot work load. The earlier work used an asynchronous secondary task presented every 22 sec regardless of flying performance. The present experiment uses a synchronous task presented only when a critical event occurred on the flying task. Both two- and four-choice visual secondary tasks were investigated. Analysis of primary flying-task results showed no decrement in error for altitude, indicating that the key assumption necessary for using a choice secondary task was satisfied. Reaction times showed significant differences between 'easy' and 'hard' flight scenarios as well as the ability to discriminate among flight tasks.

Realization of discrete quantum billiards in a two-dimensional optical lattice

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

Krimer, Dmitry O.; Max-Planck Institute for the Physics of Complex Systems, Noethnitzer Strasse 38, D-01187 Dresden; Khomeriki, Ramaz

2011-10-15

We propose a method for optical visualization of the Bose-Hubbard model with two interacting bosons in the form of two-dimensional (2D) optical lattices consisting of optical waveguides, where the waveguides at the diagonal are characterized by different refractive indices than others elsewhere, modeling the boson-boson interaction. We study the light intensity distribution function averaged over the direction of propagation for both ordered and disordered cases, exploring the sensitivity of the averaged picture with respect to the beam injection position. For our finite systems, the resulting patterns are reminiscent the ones set in billiards, and therefore we introduce a definition ofmore » discrete quantum billiards and discuss the possible relevance to its well-established continuous counterpart.« less

Neurological and developmental findings in children with cataracts.

PubMed

Pike, M G; Jan, J E; Wong, P K

1989-06-01

Ninety-seven children who were born between 1954 and 1986 and presented to the Visually Impaired Program of British Columbia's Children's Hospital, Vancouver, Canada, with a primary ophthalmologic diagnosis of cataracts, were assessed neurologically, ophthalmologically, audiologically, and developmentally. Causal factors included prenatal infection (35 cases), hereditary cataracts (22 cases), various syndromes and metabolic disorders (9 cases), trauma (1 case), and unknown (30 cases). Ninety children were diagnosed to have congenital cataracts while 7 acquired them. Findings indicated that prenatal infection continues to be a cause of infantile cataracts, despite rubella immunization; that prematurity is not, as has been stated in the past, a cause of infantile cataract; and that careful neurological, audiological, and developmental examination is vital in the assessment of likely causes of this condition.

Secondary visual workload capability with primary visual and kinesthetic-tactual displays

NASA Technical Reports Server (NTRS)

Gilson, R. D.; Burke, M. W.; Jagacinski, R. J.

1978-01-01

Subjects performed a cross-adaptive tracking task with a visual secondary display and either a visual or a quickened kinesthetic-tactual (K-T) primary display. The quickened K-T display resulted in superior secondary task performance. Comparisons of secondary workload capability with integrated and separated visual displays indicated that the superiority of the quickened K-T display was not simply due to the elimination of visual scanning. When subjects did not have to perform a secondary task, there was no significant difference between visual and quickened K-T displays in performing a critical tracking task.

An electrocorticographic BCI using code-based VEP for control in video applications: a single-subject study

PubMed Central

Kapeller, Christoph; Kamada, Kyousuke; Ogawa, Hiroshi; Prueckl, Robert; Scharinger, Josef; Guger, Christoph

2014-01-01

A brain-computer-interface (BCI) allows the user to control a device or software with brain activity. Many BCIs rely on visual stimuli with constant stimulation cycles that elicit steady-state visual evoked potentials (SSVEP) in the electroencephalogram (EEG). This EEG response can be generated with a LED or a computer screen flashing at a constant frequency, and similar EEG activity can be elicited with pseudo-random stimulation sequences on a screen (code-based BCI). Using electrocorticography (ECoG) instead of EEG promises higher spatial and temporal resolution and leads to more dominant evoked potentials due to visual stimulation. This work is focused on BCIs based on visual evoked potentials (VEP) and its capability as a continuous control interface for augmentation of video applications. One 35 year old female subject with implanted subdural grids participated in the study. The task was to select one out of four visual targets, while each was flickering with a code sequence. After a calibration run including 200 code sequences, a linear classifier was used during an evaluation run to identify the selected visual target based on the generated code-based VEPs over 20 trials. Multiple ECoG buffer lengths were tested and the subject reached a mean online classification accuracy of 99.21% for a window length of 3.15 s. Finally, the subject performed an unsupervised free run in combination with visual feedback of the current selection. Additionally, an algorithm was implemented that allowed to suppress false positive selections and this allowed the subject to start and stop the BCI at any time. The code-based BCI system attained very high online accuracy, which makes this approach very promising for control applications where a continuous control signal is needed. PMID:25147509

Capture of visual direction in dynamic vergence is reduced with flashed monocular lines.

PubMed

Jaschinski, Wolfgang; Jainta, Stephanie; Schürer, Michael

2006-08-01

The visual direction of a continuously presented monocular object is captured by the visual direction of a closely adjacent binocular object, which questions the reliability of nonius lines for measuring vergence. This was shown by Erkelens, C. J., and van Ee, R. (1997a,b) [Capture of the visual direction: An unexpected phenomenon in binocular vision. Vision Research, 37, 1193-1196; Capture of the visual direction of monocular objects by adjacent binocular objects. Vision Research, 37, 1735-1745] stimulating dynamic vergence by a counter phase oscillation of two square random-dot patterns (one to each eye) that contained a smaller central dot-free gap (of variable width) with a vertical monocular line oscillating in phase with the random-dot pattern of the respective eye; subjects adjusted the motion-amplitude of the line until it was perceived as (nearly) stationary. With a continuously presented monocular line, we replicated capture of visual direction provided the dot-free gap was narrow: the adjusted motion-amplitude of the line was similar as the motion-amplitude of the random-dot pattern, although large vergence errors occurred. However, when we flashed the line for 67 ms at the moments of maximal and minimal disparity of the vergence stimulus, we found that the adjusted motion-amplitude of the line was smaller; thus, the capture effect appeared to be reduced with flashed nonius lines. Accordingly, we found that the objectively measured vergence gain was significantly correlated (r=0.8) with the motion-amplitude of the flashed monocular line when the separation between the line and the fusion contour was at least 32 min arc. In conclusion, if one wishes to estimate the dynamic vergence response with psychophysical methods, effects of capture of visual direction can be reduced by using flashed nonius lines.

Can variations in visual behavior measures be good predictors of driver sleepiness? A real driving test study.

PubMed

Wang, Yonggang; Xin, Mengyang; Bai, Han; Zhao, Yangdong

2017-02-17

The primary purpose of this study was to examine the association between variations in visual behavior measures and subjective sleepiness levels across age groups over time to determine a quantitative method of measuring drivers' sleepiness levels. A total of 128 volunteer drivers in 4 age groups were asked to finish 2-, 3-, and 4-h continuous driving tasks on expressways, during which the driver's fixation, saccade, and blink measures were recorded by an eye-tracking system and the subjective sleepiness level was measured through the Stanford Sleepiness Scale. Two-way repeated measures analysis of variance was then used to examine the change in visual behavior measures across age groups over time and compare the interactive effects of these 2 factors on the dependent visual measures. Drivers' visual behavior measures and subjective sleepiness levels vary significantly over time but not across age groups. A statistically significant interaction between age group and driving duration was found in drivers' pupil diameter, deviation of search angle, saccade amplitude, blink frequency, blink duration, and closure duration. Additionally, change in a driver's subjective sleepiness level is positively or negatively associated with variation in visual behavior measures, and such relationships can be expressed in regression models for different period of driving duration. Driving duration affects drivers' sleepiness significantly, so the amount of continuous driving time should be strictly controlled. Moreover, driving sleepiness can be quantified through the change rate of drivers' visual behavior measures to alert drivers of sleepiness risk and to encourage rest periods. These results provide insight into potential strategies for reducing and preventing traffic accidents and injuries.

Stress Associated with Transportation: A Survey of Persons with Visual Impairments

ERIC Educational Resources Information Center

Crudden, Adele; Cmar, Jennifer L.; McDonnall, Michele C.

2017-01-01

Introduction: This study evaluated transportation-related stress and factors predicting stress among persons with visual impairments. Methods: Participants with visual impairments completed electronic surveys rating their stress levels experienced when completing various walking and public transportation tasks. They also indicated activities they…

Compatibility of Motion Facilitates Visuomotor Synchronization

ERIC Educational Resources Information Center

Hove, Michael J.; Spivey, Michael J.; Krumhansl, Carol L.

2010-01-01

Prior research indicates that synchronized tapping performance is very poor with flashing visual stimuli compared with auditory stimuli. Three finger-tapping experiments compared flashing visual metronomes with visual metronomes containing a spatial component, either compatible, incompatible, or orthogonal to the tapping action. In Experiment 1,…

Heredity Factors in Spatial Visualization.

ERIC Educational Resources Information Center

Vandenberg, S. G.

Spatial visualization is not yet clearly understood. Some researchers have concluded that two factors or abilities are involved, spatial orientation and spatial visualization. Different definitions and different tests have been proposed for these two abilities. Several studies indicate that women generally perform more poorly on spatial tests than…

Multisensory Integration Strategy for Modality-Specific Loss of Inhibition Control in Older Adults

PubMed Central

Ryu, Hokyoung; Kim, Jae-Kwan; Jeong, Eunju

2018-01-01

Older adults are known to have lesser cognitive control capability and greater susceptibility to distraction than young adults. Previous studies have reported age-related problems in selective attention and inhibitory control, yielding mixed results depending on modality and context in which stimuli and tasks were presented. The purpose of the study was to empirically demonstrate a modality-specific loss of inhibitory control in processing audio-visual information with ageing. A group of 30 young adults (mean age = 25.23, Standard Deviation (SD) = 1.86) and 22 older adults (mean age = 55.91, SD = 4.92) performed the audio-visual contour identification task (AV-CIT). We compared performance of visual/auditory identification (Uni-V, Uni-A) with that of visual/auditory identification in the presence of distraction in counterpart modality (Multi-V, Multi-A). The findings showed a modality-specific effect on inhibitory control. Uni-V performance was significantly better than Multi-V, indicating that auditory distraction significantly hampered visual target identification. However, Multi-A performance was significantly enhanced compared to Uni-A, indicating that auditory target performance was significantly enhanced by visual distraction. Additional analysis showed an age-specific effect on enhancement between Uni-A and Multi-A depending on the level of visual inhibition. Together, our findings indicated that the loss of visual inhibitory control was beneficial for the auditory target identification presented in a multimodal context in older adults. A likely multisensory information processing strategy in the older adults was further discussed in relation to aged cognition. PMID:29641462

Adaptations and Continuities in the Use and Design of Visual Representations in US Middle School Science Textbooks

ERIC Educational Resources Information Center

Lee, Victor R.

2010-01-01

Visual representations are ubiquitous in modern-day science textbooks and have in recent years become an object of criticism and scrutiny. This article examines the extent to which changes in representations in textbooks published in the USA over the past six decades have invited those critiques. Drawing from a correlational analysis of a corpus…

Developmental Changes in Infants' Visual Short-Term Memory for Location

ERIC Educational Resources Information Center

Oakes, Lisa M.; Hurley, Karinna B.; Ross-Sheehy, Shannon; Luck, Steven J.

2011-01-01

To examine the development of visual short-term memory (VSTM) for location, we presented 6- to 12-month-old infants (N = 199) with two side-by-side stimulus streams. In each stream, arrays of colored circles continually appeared, disappeared, and reappeared. In the "changing" stream, the location of one or more items changed in each cycle; in the…

The Development of SAH Reading Passage Compendium: A Tool for the Assessment of Reading Performance Related to Visual Function

ERIC Educational Resources Information Center

Chen, Ai-Hong; Buari, Noor Halilah; Jufri, Shauqiah

2017-01-01

Passages with continuous sentences are commonly used for the assessment of reading performance related to visual function, and rehabilitation in optometric practices. Passages created in native languages are crucial for a reliable interpretation in a real scenario. This study aimed to report the development of SAH Reading Passage Compendium…

A Review of the Effects of Visual-Spatial Representations and Heuristics on Word Problem Solving in Middle School Mathematics

ERIC Educational Resources Information Center

Kribbs, Elizabeth E.; Rogowsky, Beth A.

2016-01-01

Mathematics word-problems continue to be an insurmountable challenge for many middle school students. Educators have used pictorial and schematic illustrations within the classroom to help students visualize these problems. However, the data shows that pictorial representations can be more harmful than helpful in that they only display objects or…

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 participate…

Design of smart home sensor visualizations for older adults.

PubMed

Le, Thai; Reeder, Blaine; Chung, Jane; Thompson, Hilaire; Demiris, George

2014-01-01

Smart home sensor systems provide a valuable opportunity to continuously and unobtrusively monitor older adult wellness. However, the density of sensor data can be challenging to visualize, especially for an older adult consumer with distinct user needs. We describe the design of sensor visualizations informed by interviews with older adults. The goal of the visualizations is to present sensor activity data to an older adult consumer audience that supports both longitudinal detection of trends and on-demand display of activity details for any chosen day. The design process is grounded through participatory design with older adult interviews during a six-month pilot sensor study. Through a secondary analysis of interviews, we identified the visualization needs of older adults. We incorporated these needs with cognitive perceptual visualization guidelines and the emotional design principles of Norman to develop sensor visualizations. We present a design of sensor visualization that integrate both temporal and spatial components of information. The visualization supports longitudinal detection of trends while allowing the viewer to view activity within a specific date. Appropriately designed visualizations for older adults not only provide insight into health and wellness, but also are a valuable resource to promote engagement within care.

Design of smart home sensor visualizations for older adults.

PubMed

Le, Thai; Reeder, Blaine; Chung, Jane; Thompson, Hilaire; Demiris, George

2014-07-24

Smart home sensor systems provide a valuable opportunity to continuously and unobtrusively monitor older adult wellness. However, the density of sensor data can be challenging to visualize, especially for an older adult consumer with distinct user needs. We describe the design of sensor visualizations informed by interviews with older adults. The goal of the visualizations is to present sensor activity data to an older adult consumer audience that supports both longitudinal detection of trends and on-demand display of activity details for any chosen day. The design process is grounded through participatory design with older adult interviews during a six-month pilot sensor study. Through a secondary analysis of interviews, we identified the visualization needs of older adults. We incorporated these needs with cognitive perceptual visualization guidelines and the emotional design principles of Norman to develop sensor visualizations. We present a design of sensor visualization that integrate both temporal and spatial components of information. The visualization supports longitudinal detection of trends while allowing the viewer to view activity within a specific date.CONCLUSIONS: Appropriately designed visualizations for older adults not only provide insight into health and wellness, but also are a valuable resource to promote engagement within care.

Contextual effects on motion perception and smooth pursuit eye movements.

PubMed

Spering, Miriam; Gegenfurtner, Karl R

2008-08-15

Smooth pursuit eye movements are continuous, slow rotations of the eyes that allow us to follow the motion of a visual object of interest. These movements are closely related to sensory inputs from the visual motion processing system. To track a moving object in the natural environment, its motion first has to be segregated from the motion signals provided by surrounding stimuli. Here, we review experiments on the effect of the visual context on motion processing with a focus on the relationship between motion perception and smooth pursuit eye movements. While perception and pursuit are closely linked, we show that they can behave quite distinctly when required by the visual context.

Helmet-mounted display systems for flight simulation

NASA Technical Reports Server (NTRS)

Haworth, Loren A.; Bucher, Nancy M.

1989-01-01

Simulation scientists are continually improving simulation technology with the goal of more closely replicating the physical environment of the real world. The presentation or display of visual information is one area in which recent technical improvements have been made that are fundamental to conducting simulated operations close to the terrain. Detailed and appropriate visual information is especially critical for nap-of-the-earth helicopter flight simulation where the pilot maintains an 'eyes-out' orientation to avoid obstructions and terrain. This paper describes visually coupled wide field of view helmet-mounted display (WFOVHMD) system technology as a viable visual presentation system for helicopter simulation. Tradeoffs associated with this mode of presentation as well as research and training applications are discussed.

Brain functional network connectivity based on a visual task: visual information processing-related brain regions are significantly activated in the task state.

PubMed

Yang, Yan-Li; Deng, Hong-Xia; Xing, Gui-Yang; Xia, Xiao-Luan; Li, Hai-Fang

2015-02-01

It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we investigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state. Z-values in the vision-related brain regions were calculated, confirming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental findings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.

Visual input enhances selective speech envelope tracking in auditory cortex at a "cocktail party".

PubMed

Zion Golumbic, Elana; Cogan, Gregory B; Schroeder, Charles E; Poeppel, David

2013-01-23

Our ability to selectively attend to one auditory signal amid competing input streams, epitomized by the "Cocktail Party" problem, continues to stimulate research from various approaches. How this demanding perceptual feat is achieved from a neural systems perspective remains unclear and controversial. It is well established that neural responses to attended stimuli are enhanced compared with responses to ignored ones, but responses to ignored stimuli are nonetheless highly significant, leading to interference in performance. We investigated whether congruent visual input of an attended speaker enhances cortical selectivity in auditory cortex, leading to diminished representation of ignored stimuli. We recorded magnetoencephalographic signals from human participants as they attended to segments of natural continuous speech. Using two complementary methods of quantifying the neural response to speech, we found that viewing a speaker's face enhances the capacity of auditory cortex to track the temporal speech envelope of that speaker. This mechanism was most effective in a Cocktail Party setting, promoting preferential tracking of the attended speaker, whereas without visual input no significant attentional modulation was observed. These neurophysiological results underscore the importance of visual input in resolving perceptual ambiguity in a noisy environment. Since visual cues in speech precede the associated auditory signals, they likely serve a predictive role in facilitating auditory processing of speech, perhaps by directing attentional resources to appropriate points in time when to-be-attended acoustic input is expected to arrive.

Effects of pressure ulcer classification system education programme on knowledge and visual differential diagnostic ability of pressure ulcer classification and incontinence-associated dermatitis for clinical nurses in Korea.

PubMed

Lee, Yun Jin; Kim, Jung Yoon

2016-03-01

The objective of this study was to evaluate the effect of pressure ulcer classification system education on clinical nurses' knowledge and visual differential diagnostic ability of pressure ulcer (PU) classification and incontinence-associated dermatitis (IAD). One group pre and post-test was used. A convenience sample of 407 nurses, participating in PU classification education programme of continuing education, were enrolled. The education programme was composed of a 50-minute lecture on PU classification and case-studies. The PU Classification system and IAD knowledge test (PUCS-KT) and visual differential diagnostic ability tool (VDDAT), consisting of 21 photographs including clinical information were used. Paired t-test was performed using SPSS/WIN 20.0. The overall mean difference of PUCS-KT (t = -11·437, P<0·001) and VDDAT (t = -21·113, P<0·001) was significantly increased after PU classification education. Overall understanding of six PU classification and IAD after education programme was increased, but lacked visual differential diagnostic ability regarding Stage III PU, suspected deep tissue injury (SDTI), and Unstageable. Continuous differentiated education based on clinical practice is needed to improve knowledge and visual differential diagnostic ability for PU classification, and comparison experiment study is required to examine effects of education programmes. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Infants' statistical learning: 2- and 5-month-olds' segmentation of continuous visual sequences.

PubMed

Slone, Lauren Krogh; Johnson, Scott P

2015-05-01

Past research suggests that infants have powerful statistical learning abilities; however, studies of infants' visual statistical learning offer differing accounts of the developmental trajectory of and constraints on this learning. To elucidate this issue, the current study tested the hypothesis that young infants' segmentation of visual sequences depends on redundant statistical cues to segmentation. A sample of 20 2-month-olds and 20 5-month-olds observed a continuous sequence of looming shapes in which unit boundaries were defined by both transitional probability and co-occurrence frequency. Following habituation, only 5-month-olds showed evidence of statistically segmenting the sequence, looking longer to a statistically improbable shape pair than to a probable pair. These results reaffirm the power of statistical learning in infants as young as 5 months but also suggest considerable development of statistical segmentation ability between 2 and 5 months of age. Moreover, the results do not support the idea that infants' ability to segment visual sequences based on transitional probabilities and/or co-occurrence frequencies is functional at the onset of visual experience, as has been suggested previously. Rather, this type of statistical segmentation appears to be constrained by the developmental state of the learner. Factors contributing to the development of statistical segmentation ability during early infancy, including memory and attention, are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

Ciliary muscle contraction force and trapezius muscle activity during manual tracking of a moving visual target.

PubMed

Domkin, Dmitry; Forsman, Mikael; Richter, Hans O

2016-06-01

Previous studies have shown an association of visual demands during near work and increased activity of the trapezius muscle. Those studies were conducted under stationary postural conditions with fixed gaze and artificial visual load. The present study investigated the relationship between ciliary muscle contraction force and trapezius muscle activity across individuals during performance of a natural dynamic motor task under free gaze conditions. Participants (N=11) tracked a moving visual target with a digital pen on a computer screen. Tracking performance, eye refraction and trapezius muscle activity were continuously measured. Ciliary muscle contraction force was computed from eye accommodative response. There was a significant Pearson correlation between ciliary muscle contraction force and trapezius muscle activity on the tracking side (0.78, p<0.01) and passive side (0.64, p<0.05). The study supports the hypothesis that high visual demands, leading to an increased ciliary muscle contraction during continuous eye-hand coordination, may increase trapezius muscle tension and thus contribute to the development of musculoskeletal complaints in the neck-shoulder area. Further experimental studies are required to clarify whether the relationship is valid within each individual or may represent a general personal trait, when individuals with higher eye accommodative response tend to have higher trapezius muscle activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

JPL Earth Science Center Visualization Multitouch Table

NASA Astrophysics Data System (ADS)

Kim, R.; Dodge, K.; Malhotra, S.; Chang, G.

2014-12-01

JPL Earth Science Center Visualization table is a specialized software and hardware to allow multitouch, multiuser, and remote display control to create seamlessly integrated experiences to visualize JPL missions and their remote sensing data. The software is fully GIS capable through time aware OGC WMTS using Lunar Mapping and Modeling Portal as the GIS backend to continuously ingest and retrieve realtime remote sending data and satellite location data. 55 inch and 82 inch unlimited finger count multitouch displays allows multiple users to explore JPL Earth missions and visualize remote sensing data through very intuitive and interactive touch graphical user interface. To improve the integrated experience, Earth Science Center Visualization Table team developed network streaming which allows table software to stream data visualization to near by remote display though computer network. The purpose of this visualization/presentation tool is not only to support earth science operation, but specifically designed for education and public outreach and will significantly contribute to STEM. Our presentation will include overview of our software, hardware, and showcase of our system.

Pursuit Eye Movements

NASA Technical Reports Server (NTRS)

Krauzlis, Rich; Stone, Leland; Null, Cynthia H. (Technical Monitor)

1998-01-01

When viewing objects, primates use a combination of saccadic and pursuit eye movements to stabilize the retinal image of the object of regard within the high-acuity region near the fovea. Although these movements involve widespread regions of the nervous system, they mix seamlessly in normal behavior. Saccades are discrete movements that quickly direct the eyes toward a visual target, thereby translating the image of the target from an eccentric retinal location to the fovea. In contrast, pursuit is a continuous movement that slowly rotates the eyes to compensate for the motion of the visual target, minimizing the blur that can compromise visual acuity. While other mammalian species can generate smooth optokinetic eye movements - which track the motion of the entire visual surround - only primates can smoothly pursue a single small element within a complex visual scene, regardless of the motion elsewhere on the retina. This ability likely reflects the greater ability of primates to segment the visual scene, to identify individual visual objects, and to select a target of interest.

Pictorial communication in virtual and real environments

NASA Technical Reports Server (NTRS)

Ellis, Stephen R. (Editor)

1991-01-01

Papers about the communication between human users and machines in real and synthetic environments are presented. Individual topics addressed include: pictorial communication, distortions in memory for visual displays, cartography and map displays, efficiency of graphical perception, volumetric visualization of 3D data, spatial displays to increase pilot situational awareness, teleoperation of land vehicles, computer graphics system for visualizing spacecraft in orbit, visual display aid for orbital maneuvering, multiaxis control in telemanipulation and vehicle guidance, visual enhancements in pick-and-place tasks, target axis effects under transformed visual-motor mappings, adapting to variable prismatic displacement. Also discussed are: spatial vision within egocentric and exocentric frames of reference, sensory conflict in motion sickness, interactions of form and orientation, perception of geometrical structure from congruence, prediction of three-dimensionality across continuous surfaces, effects of viewpoint in the virtual space of pictures, visual slant underestimation, spatial constraints of stereopsis in video displays, stereoscopic stance perception, paradoxical monocular stereopsis and perspective vergence. (No individual items are abstracted in this volume)

Number versus Extent in Newborns' Spontaneous Preference for Collections of Dots

ERIC Educational Resources Information Center

Turati, Chiara; Gava, Lucia; Valenza, Eloisa; Ghirardi, Valentina

2013-01-01

This study investigated processing of number and extent in newborns. Using visual preference, we showed that newborns discriminated between small sets of dot collections relying solely on implicit numerical information when non-numerical continuous variables were strictly controlled (Experiment 1), and solely on continuous information when…

40 CFR 63.11584 - What are my initial and continuous compliance management practice requirements?

Code of Federal Regulations, 2010 CFR

2010-07-01

... compliance management practice requirements? 63.11584 Section 63.11584 Protection of Environment... What are my initial and continuous compliance management practice requirements? (a) For each new and... gr/dscf, the management practice requirements are as follows: (1) You must conduct an initial visual...

49 CFR 452.9 - Elements of a continuous examination program.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., DEPARTMENT OF HOMELAND SECURITY SAFETY APPROVAL OF CARGO CONTAINERS EXAMINATION OF CONTAINERS § 452.9... following minimum requirements: (1) A thorough examination that must include a detailed visual inspection... disclosed by the examination must be corrected by the owner before the container is continued in service. A...

49 CFR 452.9 - Elements of a continuous examination program.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., DEPARTMENT OF HOMELAND SECURITY SAFETY APPROVAL OF CARGO CONTAINERS EXAMINATION OF CONTAINERS § 452.9... following minimum requirements: (1) A thorough examination that must include a detailed visual inspection... disclosed by the examination must be corrected by the owner before the container is continued in service. A...

49 CFR 452.9 - Elements of a continuous examination program.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., DEPARTMENT OF HOMELAND SECURITY SAFETY APPROVAL OF CARGO CONTAINERS EXAMINATION OF CONTAINERS § 452.9... following minimum requirements: (1) A thorough examination that must include a detailed visual inspection... disclosed by the examination must be corrected by the owner before the container is continued in service. A...

49 CFR 452.9 - Elements of a continuous examination program.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., DEPARTMENT OF HOMELAND SECURITY SAFETY APPROVAL OF CARGO CONTAINERS EXAMINATION OF CONTAINERS § 452.9... following minimum requirements: (1) A thorough examination that must include a detailed visual inspection... disclosed by the examination must be corrected by the owner before the container is continued in service. A...

49 CFR 452.9 - Elements of a continuous examination program.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., DEPARTMENT OF HOMELAND SECURITY SAFETY APPROVAL OF CARGO CONTAINERS EXAMINATION OF CONTAINERS § 452.9... following minimum requirements: (1) A thorough examination that must include a detailed visual inspection... disclosed by the examination must be corrected by the owner before the container is continued in service. A...

Design, Form, and Function in Art Education

ERIC Educational Resources Information Center

Vande Zande, Robin

2007-01-01

Human beings are influenced by design every day through continuous contact with functional form in and through visual culture. They encounter a continuous current of such new styles as clothing fashions, architecture, furniture and advertisements. The American pursuit of happiness has become related to an increasing flow of products and…

Preserved subliminal processing and impaired conscious access in schizophrenia

PubMed Central

Del Cul, Antoine; Dehaene, Stanislas; Leboyer, Marion

2006-01-01

Background Studies of visual backward masking have frequently revealed an elevated masking threshold in schizophrenia. This finding has frequently been interpreted as indicating a low-level visual deficit. However, more recent models suggest that masking may also involve late and higher-level integrative processes, while leaving intact early “bottom-up” visual processing. Objectives We tested the hypothesis that the backward masking deficit in schizophrenia corresponds to a deficit in the late stages of conscious perception, whereas the subliminal processing of masked stimuli is fully preserved. Method 28 patients with schizophrenia and 28 normal controls performed two backward-masking experiments. We used Arabic digits as stimuli and varied quasi-continuously the interval with a subsequent mask, thus allowing us to progressively “unmask” the stimuli. We finely quantified their degree of visibility using both objective and subjective measures to evaluate the threshold duration for access to consciousness. We also studied the priming effect caused by the variably masked numbers on a comparison task performed on a subsequently presented and highly visible target number. Results The threshold delay between digit and mask necessary for the conscious perception of the masked stimulus was longer in patients compared to control subjects. This higher consciousness threshold in patients was confirmed by an objective and a subjective measure, and both measures were highly correlated for patients as well as for controls. However, subliminal priming of masked numbers was effective and identical in patients compared to controls. Conclusions Access to conscious report of masked stimuli is impaired in schizophrenia, while fast bottom-up processing of the same stimuli, as assessed by subliminal priming, is preserved. These findings suggest a high-level origin of the masking deficit in schizophrenia, although they leave open for further research its exact relation to previously identified bottom-up visual processing abnormalities. PMID:17146006

Glued to Which Face? Attentional Priority Effect of Female Babyface and Male Mature Face

PubMed Central

Zheng, Wenwen; Luo, Ting; Hu, Chuan-Peng; Peng, Kaiping

2018-01-01

A more babyfaced individual is perceived as more child-like and this impression from babyface, as known as babyface effect, has an impact on social life among various age groups. In this study, the influence of babyfaces on visual selective attention was tested by cognitive task, demonstrating that the female babyface and male mature face would draw participants’ attention so that they take their eyes off more slowly. In Experiment 1, a detection task was applied to test the influence of babyfaces on visual selective attention. In this experiment, a babyface and a mature face with the same gender were presented simultaneously with a letter on one of them. The reaction time was shorter when the target letter was overlaid with a female babyface or male mature face, suggesting an attention capture effect. To explore how this competition influenced by attentional resources, we conducted Experiment 2 with a spatial cueing paradigm and controlled the attentional resources by cueing validity and inter-stimulus interval. In this task, the female babyface and male mature face prolonged responses to the spatially separated targets under the condition of an invalid and long interval pre-cue. This observation replicated the result of Experiment 1. This indicates that the female babyface and male mature face glued visual selective attention once attentional resources were directed to them. To further investigate the subliminal influence from a babyface, we used continuous flash suppression paradigm in Experiment 3. The results, again, showed the advantage of the female babyfaces and male mature faces: they broke the suppression faster than other faces. Our results provide primary evidence that the female babyfaces and male mature faces can reliably glue the visual selective attention, both supra- and sub-liminally. PMID:29559946

Glued to Which Face? Attentional Priority Effect of Female Babyface and Male Mature Face.

PubMed

Zheng, Wenwen; Luo, Ting; Hu, Chuan-Peng; Peng, Kaiping

2018-01-01

A more babyfaced individual is perceived as more child-like and this impression from babyface, as known as babyface effect, has an impact on social life among various age groups. In this study, the influence of babyfaces on visual selective attention was tested by cognitive task, demonstrating that the female babyface and male mature face would draw participants' attention so that they take their eyes off more slowly. In Experiment 1, a detection task was applied to test the influence of babyfaces on visual selective attention. In this experiment, a babyface and a mature face with the same gender were presented simultaneously with a letter on one of them. The reaction time was shorter when the target letter was overlaid with a female babyface or male mature face, suggesting an attention capture effect. To explore how this competition influenced by attentional resources, we conducted Experiment 2 with a spatial cueing paradigm and controlled the attentional resources by cueing validity and inter-stimulus interval. In this task, the female babyface and male mature face prolonged responses to the spatially separated targets under the condition of an invalid and long interval pre-cue. This observation replicated the result of Experiment 1. This indicates that the female babyface and male mature face glued visual selective attention once attentional resources were directed to them. To further investigate the subliminal influence from a babyface, we used continuous flash suppression paradigm in Experiment 3. The results, again, showed the advantage of the female babyfaces and male mature faces: they broke the suppression faster than other faces. Our results provide primary evidence that the female babyfaces and male mature faces can reliably glue the visual selective attention, both supra- and sub-liminally.

The Advanced Glaucoma Intervention Study (AGIS): 1. Study design and methods and baseline characteristics of study patients.

PubMed

Ederer, F; Gaasterland, D E; Sullivan, E K

1994-08-01

Medical therapy has been the standard initial treatment for open-angle glaucoma. When some visual field has been lost and maximum tolerated and effective medical therapy does not succeed in controlling the disease, the patient is considered to have advanced glaucoma, and the first of a potential sequence of surgical treatments is usually indicated. Little is known about the long-term course and prognosis of advanced glaucoma or about the long-term effectiveness of sequential surgical treatments in controlling the disease and preventing vision loss and blindness. The Advanced Glaucoma Intervention Study was designed to study, in advanced glaucoma, the long-term clinical course and prognosis, and, in a randomized trial, the comparative outcomes of two sequences of surgical treatments. Toward these goals, 789 eyes in 591 patients were enrolled at 11 clinical centers between 1988 and 1992. Follow-up will continue until 1996. Eyes were randomly assigned to one of two sequences of surgical treatments. One sequence begins with argon laser trabeculoplasty (ALT), is followed by trabeculectomy, an incisional surgical filtering procedure, should ALT fail to control the disease, and by a second trabeculectomy should the first trabeculectomy fail. The other sequence begins with trabeculectomy, is followed by ALT should the trabeculectomy fail, and by a second trabeculectomy should ALT fail. The main outcome of interest is visual function (visual field and visual acuity). Other important outcomes are intraocular pressure, complications of surgery, time to treatment failure, and extent of need for additional medical therapy. We present in this paper the rationale, objectives, design and methods of the study, and the baseline characteristics of study patients and eyes.

Using Visuals To Develop Reading Vocabulary.

ERIC Educational Resources Information Center

Bazeli, Marilyn J.; Olle, Ruth E.

This paper discusses research findings regarding vocabulary instruction and reading comprehension and suggests methods to develop vocabulary using visual aids. As indicated by the research, vocabulary instruction is necessary and can lead to improved comprehension; there also appears to be a strong need to relate concrete visual experiences to…

Perceptual suppression revealed by adaptive multi-scale entropy analysis of local field potential in monkey visual cortex.

PubMed

Hu, Meng; Liang, Hualou

2013-04-01

Generalized flash suppression (GFS), in which a salient visual stimulus can be rendered invisible despite continuous retinal input, provides a rare opportunity to directly study the neural mechanism of visual perception. Previous work based on linear methods, such as spectral analysis, on local field potential (LFP) during GFS has shown that the LFP power at distinctive frequency bands are differentially modulated by perceptual suppression. Yet, the linear method alone may be insufficient for the full assessment of neural dynamic due to the fundamentally nonlinear nature of neural signals. In this study, we set forth to analyze the LFP data collected from multiple visual areas in V1, V2 and V4 of macaque monkeys while performing the GFS task using a nonlinear method - adaptive multi-scale entropy (AME) - to reveal the neural dynamic of perceptual suppression. In addition, we propose a new cross-entropy measure at multiple scales, namely adaptive multi-scale cross-entropy (AMCE), to assess the nonlinear functional connectivity between two cortical areas. We show that: (1) multi-scale entropy exhibits percept-related changes in all three areas, with higher entropy observed during perceptual suppression; (2) the magnitude of the perception-related entropy changes increases systematically over successive hierarchical stages (i.e. from lower areas V1 to V2, up to higher area V4); and (3) cross-entropy between any two cortical areas reveals higher degree of asynchrony or dissimilarity during perceptual suppression, indicating a decreased functional connectivity between cortical areas. These results, taken together, suggest that perceptual suppression is related to a reduced functional connectivity and increased uncertainty of neural responses, and the modulation of perceptual suppression is more effective at higher visual cortical areas. AME is demonstrated to be a useful technique in revealing the underlying dynamic of nonlinear/nonstationary neural signal.

Integrating Time-Synchronized Video with Other Geospatial and Temporal Data for Remote Science Operations

NASA Technical Reports Server (NTRS)

Cohen, Tamar E.; Lees, David S.; Deans, Matthew C.; Lim, Darlene S. S.; Lee, Yeon Jin Grace

2018-01-01

Exploration Ground Data Systems (xGDS) supports rapid scientific decision making by synchronizing video in context with map, instrument data visualization, geo-located notes and any other collected data. xGDS is an open source web-based software suite developed at NASA Ames Research Center to support remote science operations in analog missions and prototype solutions for remote planetary exploration. (See Appendix B) Typical video systems are designed to play or stream video only, independent of other data collected in the context of the video. Providing customizable displays for monitoring live video and data as well as replaying recorded video and data helps end users build up a rich situational awareness. xGDS was designed to support remote field exploration with unreliable networks. Commercial digital recording systems operate under the assumption that there is a stable and reliable network between the source of the video and the recording system. In many field deployments and space exploration scenarios, this is not the case - there are both anticipated and unexpected network losses. xGDS' Video Module handles these interruptions, storing the available video, organizing and characterizing the dropouts, and presenting the video for streaming or replay to the end user including visualization of the dropouts. Scientific instruments often require custom or expensive software to analyze and visualize collected data. This limits the speed at which the data can be visualized and limits access to the data to those users with the software. xGDS' Instrument Module integrates with instruments that collect and broadcast data in a single snapshot or that continually collect and broadcast a stream of data. While seeing a visualization of collected instrument data is informative, showing the context for the collected data, other data collected nearby along with events indicating current status helps remote science teams build a better understanding of the environment. Further, sharing geo-located, tagged notes recorded by the scientists and others on the team spurs deeper analysis of the data.