Comparison of the HiFocus Mid-Scala and HiFocus 1J Electrode Array: Angular Insertion Depths and Speech Perception Outcomes.

PubMed

van der Jagt, M Annerie; Briaire, Jeroen J; Verbist, Berit M; Frijns, Johan H M

2016-01-01

The HiFocus Mid-Scala (MS) electrode array has recently been introduced onto the market. This precurved design with a targeted mid-scalar intracochlear position pursues an atraumatic insertion and optimal distance for neural stimulation. In this study we prospectively examined the angular insertion depth achieved and speech perception outcomes resulting from the HiFocus MS electrode array for 6 months after implantation, and retrospectively compared these with the HiFocus 1J lateral wall electrode array. The mean angular insertion depth within the MS population (n = 96) was found at 470°. This was 50° shallower but more consistent than the 1J electrode array (n = 110). Audiological evaluation within a subgroup, including only postlingual, unilaterally implanted, adult cochlear implant recipients who were matched on preoperative speech perception scores and the duration of deafness (MS = 32, 1J = 32), showed no difference in speech perception outcomes between the MS and 1J groups. Furthermore, speech perception outcome was not affected by the angular insertion depth or frequency mismatch. © 2016 S. Karger AG, Basel.

Depth Perception In Remote Stereoscopic Viewing Systems

NASA Technical Reports Server (NTRS)

Diner, Daniel B.; Von Sydow, Marika

1989-01-01

Report describes theoretical and experimental studies of perception of depth by human operators through stereoscopic video systems. Purpose of such studies to optimize dual-camera configurations used to view workspaces of remote manipulators at distances of 1 to 3 m from cameras. According to analysis, static stereoscopic depth distortion decreased, without decreasing stereoscopitc depth resolution, by increasing camera-to-object and intercamera distances and camera focal length. Further predicts dynamic stereoscopic depth distortion reduced by rotating cameras around center of circle passing through point of convergence of viewing axes and first nodal points of two camera lenses.

Long-Duration Spaceflight Increases Depth Ambiguity of Reversible Perspective Figures

PubMed Central

Clément, Gilles; Allaway, Heather C. M.; Demel, Michael; Golemis, Adrianos; Kindrat, Alexandra N.; Melinyshyn, Alexander N.; Merali, Tahir; Thirsk, Robert

2015-01-01

The objective of this study was to investigate depth perception in astronauts during and after spaceflight by studying their sensitivity to reversible perspective figures in which two-dimensional images could elicit two possible depth representations. Other ambiguous figures that did not give rise to a perception of illusory depth were used as controls. Six astronauts and 14 subjects were tested in the laboratory during three sessions for evaluating the variability of their responses in normal gravity. The six astronauts were then tested during four sessions while on board the International Space Station for 5–6 months. They were finally tested immediately after return to Earth and up to one week later. The reaction time decreased throughout the sessions, thus indicating a learning effect. However, the time to first percept reversal and the number of reversals were not different in orbit and after the flight compared to before the flight. On Earth, when watching depth-ambiguous perspective figures, all subjects reported seeing one three-dimensional interpretation more often than the other, i.e. a ratio of about 70–30%. In weightlessness this asymmetry gradually disappeared and after 3 months in orbit both interpretations were seen for the same duration. These results indicate that the perception of “illusory” depth is altered in astronauts during spaceflight. This increased depth ambiguity is attributed to the lack of the gravitational reference and the eye-ground elevation for interpreting perspective depth cues. PMID:26146839

Effect of short-term exposure to stereoscopic three-dimensional flight displays on real-world depth perception

NASA Technical Reports Server (NTRS)

Busquets, Anthony M.; Parrish, Russell V.; Williams, Steven P.

1991-01-01

High-fidelity color pictorial displays that incorporate depth cues in the display elements are currently available. Depth cuing applied to advanced head-down flight display concepts potentially enhances the pilot's situational awareness and improves task performance. Depth cues provided by stereopsis exhibit constraints that must be fully understood so depth cuing enhancements can be adequately realized and exploited. A fundamental issue (the goal of this investigation) is whether the use of head-down stereoscopic displays in flight applications degrade the real-world depth perception of pilots using such displays. Stereoacuity tests are used in this study as the measure of interest. Eight pilots flew repeated simulated landing approaches using both nonstereo and stereo 3-D head-down pathway-in-the-sky displays. At this decision height of each approach (where the pilot changes to an out-the-window view to obtain real-world visual references) the pilots changed to a stereoacuity test that used real objects. Statistical analysis of stereoacuity measures (data for a control condition of no exposure to any electronic flight display compared with data for changes from nonstereo and from stereo displays) reveals no significant differences for any of the conditions. Therefore, changing from short-term exposure to a head-down stereo display has no more effect on real-world relative depth perception than does changing from a nonstereo display. However, depth perception effects based on sized and distance judgements and on long-term exposure remain issues to be investigated.

3D Visualizations of Abstract DataSets

DTIC Science & Technology

2010-08-01

contrasts no shadows, drop shadows and drop lines. 15. SUBJECT TERMS 3D displays, 2.5D displays, abstract network visualizations, depth perception , human...altitude perception in airspace management and airspace route planning—simulated reality visualizations that employ altitude and heading as well as...cues employed by display designers for depicting real-world scenes on a flat surface can be applied to create a perception of depth for abstract

Stereoscopic perception of real depths at large distances.

PubMed

Palmisano, Stephen; Gillam, Barbara; Govan, Donovan G; Allison, Robert S; Harris, Julie M

2010-06-01

There has been no direct examination of stereoscopic depth perception at very large observation distances and depths. We measured perceptions of depth magnitude at distances where it is frequently reported without evidence that stereopsis is non-functional. We adapted methods pioneered at distances up to 9 m by R. S. Allison, B. J. Gillam, and E. Vecellio (2009) for use in a 381-m-long railway tunnel. Pairs of Light Emitting Diode (LED) targets were presented either in complete darkness or with the environment lit as far as the nearest LED (the observation distance). We found that binocular, but not monocular, estimates of the depth between pairs of LEDs increased with their physical depths up to the maximum depth separation tested (248 m). Binocular estimates of depth were much larger with a lit foreground than in darkness and increased as the observation distance increased from 20 to 40 m, indicating that binocular disparity can be scaled for much larger distances than previously realized. Since these observation distances were well beyond the range of vertical disparity and oculomotor cues, this scaling must rely on perspective cues. We also ran control experiments at smaller distances, which showed that estimates of depth and distance correlate poorly and that our metric estimation method gives similar results to a comparison method under the same conditions.

Increasing Depth of Self Perception in Children through a Course in Psychology: A Feasibility Study of a Teacher Training Program

ERIC Educational Resources Information Center

Long, Barbara Ellis

1974-01-01

Tests the hypothesis that teachers can learn about and use a psychological curriculum without extensive prior study of psychology, and that students will show gain in depth of self-perception and higher levels of psychological maturity. (Author/RP)

The facing bias in biological motion perception: structure, kinematics, and body parts.

PubMed

Schouten, Ben; Troje, Nikolaus F; Verfaillie, Karl

2011-01-01

Depth-ambiguous point-light walkers (PLWs) elicit a facing bias: Observers perceive a PLW as facing toward them more often than as facing away (Vanrie,Dekeyser, & Verfaillie, Perception, 33, 547-560, 2004). While the facing bias correlates with the PLW's perceived gender (Brooks et al., Current Biology, 18, R728-R729, 2008; Schouten, Troje, Brooks, van der Zwan, & Verfaillie, Attention, Perception, & Psychophysics, 72,1256-1260, 2010), it remains unclear whether the change in perceived in-depth orientation is caused by a change in perceived gender. In Experiment 1, we show that structural and kinematic stimulus properties that lead to the same changes in perceived gender elicit opposite changes in perceived in-depth orientation, indicating that the relation between perceived gender and in-depth orientation is not causal. The results of Experiments 2 and 3 further suggest that the perceived in-depth orientation of PLWs is strongly affected by locally acting stimulus properties. The facing bias seems to be induced by stimulus properties in the lower part of the PLW.

Activation of the Human MT Complex by Motion in Depth Induced by a Moving Cast Shadow

PubMed Central

Katsuyama, Narumi; Usui, Nobuo; Taira, Masato

2016-01-01

A moving cast shadow is a powerful monocular depth cue for motion perception in depth. For example, when a cast shadow moves away from or toward an object in a two-dimensional plane, the object appears to move toward or away from the observer in depth, respectively, whereas the size and position of the object are constant. Although the cortical mechanisms underlying motion perception in depth by cast shadow are unknown, the human MT complex (hMT+) is likely involved in the process, as it is sensitive to motion in depth represented by binocular depth cues. In the present study, we examined this possibility by using a functional magnetic resonance imaging (fMRI) technique. First, we identified the cortical regions sensitive to the motion of a square in depth represented via binocular disparity. Consistent with previous studies, we observed significant activation in the bilateral hMT+, and defined functional regions of interest (ROIs) there. We then investigated the activity of the ROIs during observation of the following stimuli: 1) a central square that appeared to move back and forth via a moving cast shadow (mCS); 2) a segmented and scrambled cast shadow presented beside the square (sCS); and 3) no cast shadow (nCS). Participants perceived motion of the square in depth in the mCS condition only. The activity of the hMT+ was significantly higher in the mCS compared with the sCS and nCS conditions. Moreover, the hMT+ was activated equally in both hemispheres in the mCS condition, despite presentation of the cast shadow in the bottom-right quadrant of the stimulus. Perception of the square moving in depth across visual hemifields may be reflected in the bilateral activation of the hMT+. We concluded that the hMT+ is involved in motion perception in depth induced by moving cast shadow and by binocular disparity. PMID:27597999

Feature-location binding in 3D: Feature judgments are biased by 2D location but not position-in-depth

PubMed Central

Finlayson, Nonie J.; Golomb, Julie D.

2016-01-01

A fundamental aspect of human visual perception is the ability to recognize and locate objects in the environment. Importantly, our environment is predominantly three-dimensional (3D), but while there is considerable research exploring the binding of object features and location, it is unknown how depth information interacts with features in the object binding process. A recent paradigm called the spatial congruency bias demonstrated that 2D location is fundamentally bound to object features (Golomb, Kupitz, & Thiemann, 2014), such that irrelevant location information biases judgments of object features, but irrelevant feature information does not bias judgments of location or other features. Here, using the spatial congruency bias paradigm, we asked whether depth is processed as another type of location, or more like other features. We initially found that depth cued by binocular disparity biased judgments of object color. However, this result seemed to be driven more by the disparity differences than the depth percept: Depth cued by occlusion and size did not bias color judgments, whereas vertical disparity information (with no depth percept) did bias color judgments. Our results suggest that despite the 3D nature of our visual environment, only 2D location information – not position-in-depth – seems to be automatically bound to object features, with depth information processed more similarly to other features than to 2D location. PMID:27468654

Feature-location binding in 3D: Feature judgments are biased by 2D location but not position-in-depth.

PubMed

Finlayson, Nonie J; Golomb, Julie D

2016-10-01

A fundamental aspect of human visual perception is the ability to recognize and locate objects in the environment. Importantly, our environment is predominantly three-dimensional (3D), but while there is considerable research exploring the binding of object features and location, it is unknown how depth information interacts with features in the object binding process. A recent paradigm called the spatial congruency bias demonstrated that 2D location is fundamentally bound to object features, such that irrelevant location information biases judgments of object features, but irrelevant feature information does not bias judgments of location or other features. Here, using the spatial congruency bias paradigm, we asked whether depth is processed as another type of location, or more like other features. We initially found that depth cued by binocular disparity biased judgments of object color. However, this result seemed to be driven more by the disparity differences than the depth percept: Depth cued by occlusion and size did not bias color judgments, whereas vertical disparity information (with no depth percept) did bias color judgments. Our results suggest that despite the 3D nature of our visual environment, only 2D location information - not position-in-depth - seems to be automatically bound to object features, with depth information processed more similarly to other features than to 2D location. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of visual path information on human heading perception during rotation.

PubMed

Li, Li; Chen, Jing; Peng, Xiaozhe

2009-03-31

How does visual path information influence people's perception of their instantaneous direction of self-motion (heading)? We have previously shown that humans can perceive heading without direct access to visual path information. Here we vary two key parameters for estimating heading from optic flow, the field of view (FOV) and the depth range of environmental points, to investigate the conditions under which visual path information influences human heading perception. The display simulated an observer traveling on a circular path. Observers used a joystick to rotate their line of sight until deemed aligned with true heading. Four FOV sizes (110 x 94 degrees, 48 x 41 degrees, 16 x 14 degrees, 8 x 7 degrees) and depth ranges (6-50 m, 6-25 m, 6-12.5 m, 6-9 m) were tested. Consistent with our computational modeling results, heading bias increased with the reduction of FOV or depth range when the display provided a sequence of velocity fields but no direct path information. When the display provided path information, heading bias was not influenced as much by the reduction of FOV or depth range. We conclude that human heading and path perception involve separate visual processes. Path helps heading perception when the display does not contain enough optic-flow information for heading estimation during rotation.

Effects of Optical Combiner and IPD Change for Convergence on Near-Field Depth Perception in an Optical See-Through HMD.

PubMed

Lee, Sangyoon; Hu, Xinda; Hua, Hong

2016-05-01

Many error sources have been explored in regards to the depth perception problem in augmented reality environments using optical see-through head-mounted displays (OST-HMDs). Nonetheless, two error sources are commonly neglected: the ray-shift phenomenon and the change in interpupillary distance (IPD). The first source of error arises from the difference in refraction for virtual and see-through optical paths caused by an optical combiner, which is required of OST-HMDs. The second occurs from the change in the viewer's IPD due to eye convergence. In this paper, we analyze the effects of these two error sources on near-field depth perception and propose methods to compensate for these two types of errors. Furthermore, we investigate their effectiveness through an experiment comparing the conditions with and without our error compensation methods applied. In our experiment, participants estimated the egocentric depth of a virtual and a physical object located at seven different near-field distances (40∼200 cm) using a perceptual matching task. Although the experimental results showed different patterns depending on the target distance, the results demonstrated that the near-field depth perception error can be effectively reduced to a very small level (at most 1 percent error) by compensating for the two mentioned error sources.

Monocular zones in stereoscopic scenes: A useful source of information for human binocular vision?

NASA Astrophysics Data System (ADS)

Harris, Julie M.

2010-02-01

When an object is closer to an observer than the background, the small differences between right and left eye views are interpreted by the human brain as depth. This basic ability of the human visual system, called stereopsis, lies at the core of all binocular three-dimensional (3-D) perception and related technological display development. To achieve stereopsis, it is traditionally assumed that corresponding locations in the right and left eye's views must first be matched, then the relative differences between right and left eye locations are used to calculate depth. But this is not the whole story. At every object-background boundary, there are regions of the background that only one eye can see because, in the other eye's view, the foreground object occludes that region of background. Such monocular zones do not have a corresponding match in the other eye's view and can thus cause problems for depth extraction algorithms. In this paper I will discuss evidence, from our knowledge of human visual perception, illustrating that monocular zones do not pose problems for our human visual systems, rather, our visual systems can extract depth from such zones. I review the relevant human perception literature in this area, and show some recent data aimed at quantifying the perception of depth from monocular zones. The paper finishes with a discussion of the potential importance of considering monocular zones, for stereo display technology and depth compression algorithms.

Remote operation: a selective review of research into visual depth perception.

PubMed

Reinhardt-Rutland, A H

1996-07-01

Some perceptual motor operations are performed remotely; examples include the handling of life-threatening materials and surgical procedures. A camera conveys the site of operation to a TV monitor, so depth perception relies mainly on pictorial information, perhaps with enhancement of the occlusion cue by motion. However, motion information such as motion parallax is not likely to be important. The effectiveness of pictorial information is diminished by monocular and binocular information conveying flatness of the screen and by difficulties in scaling: Only a degree of relative depth can be conveyed. Furthermore, pictorial information can mislead. Depth perception is probably adequate in remote operation, if target objects are well separated, with well-defined edges and familiar shapes. Stereoscopic viewing systems are being developed to introduce binocular information to remote operation. However, stereoscopic viewing is problematic because binocular disparity conflicts with convergence and monocular information. An alternative strategy to improve precision in remote operation may be to rely on individuals who lack binocular function: There is redundancy in depth information, and such individuals seem to compensate for the lack of binocular function.

Various Measures of the Effectiveness of Yellow Goggles

DTIC Science & Technology

1980-10-08

technique which is widely used r.o improve vision under these conditions is the use of yellow goggles. Skiers commonly don yellow goggles...different laboratory studies are presented. Two of the studies were of depth perception, since skiers believe that yellow goggles help them...selected for measurement because of practical considerations and theoretical implications. EXPERIMENTS ON DEPTH PERCEPTION Background Since skiers

The effects of quantity and depth of processing on children's time perception.

PubMed

Arlin, M

1986-08-01

Two experiments were conducted to investigate the effects of quantity and depth of processing on children's time perception. These experiments tested the appropriateness of two adult time-perception models (attentional and storage size) for younger ages. Children were given stimulus sets of equal time which varied by level of processing (deep/shallow) and quantity (list length). In the first experiment, 28 children in Grade 6 reproduced presentation times of various quantities of pictures under deep (living/nonliving categorization) or shallow (repeating label) conditions. Students also compared pairs of durations. In the second experiment, 128 children in Grades K, 2, 4, and 6 reproduced presentation times under similar conditions with three or six pictures and with deep or shallow processing requirements. Deep processing led to decreased estimation of time. Higher quantity led to increased estimation of time. Comparative judgments were influenced by quantity. The interaction between age and depth of processing was significant. Older children were more affected by depth differences than were younger children. Results were interpreted as supporting different aspects of each adult model as explanations of children's time perception. The processing effect supported the attentional model and the quantity effect supported the storage size model.

Path perception during rotation: influence of instructions, depth range, and dot density

NASA Technical Reports Server (NTRS)

Li, Li; Warren, William H Jr

2004-01-01

How do observers perceive their direction of self-motion when traveling on a straight path while their eyes are rotating? Our previous findings suggest that information from retinal flow and extra-retinal information about eye movements are each sufficient to solve this problem for both perception and active control of self-motion [Vision Res. 40 (2000) 3873; Psych. Sci. 13 (2002) 485]. In this paper, using displays depicting translation with simulated eye rotation, we investigated how task variables such as instructions, depth range, and dot density influenced the visual system's reliance on retinal vs. extra-retinal information for path perception during rotation. We found that path errors were small when observers expected to travel on a straight path or with neutral instructions, but errors increased markedly when observers expected to travel on a curved path. Increasing depth range or dot density did not improve path judgments. We conclude that the expectation of the shape of an upcoming path can influence the interpretation of the ambiguous retinal flow. A large depth range and dense motion parallax are not essential for accurate path perception during rotation, but reference objects and a large field of view appear to improve path judgments.

Depth Perception in Visual Simulation.

DTIC Science & Technology

1980-08-01

effect. Journal of Experimental Psychology, 1953, 45, 205-217. Wallach, H., O’Connell, D. N., & Neisser , U . The memory effect of visual perception of...Wallach and O’Connell labelled this the Kinetic Depth Effect. Wallach, O’Connell, and Neisser (1953) found that once depth had been established...right of fixation in the left eye. The converse is true for objects located 10 uL 0 L-I. M4 ’I! .- 4J Cd > 9 )( C.) U )d 0 0 4- -0 4 C4 J )0 -I,--4 0

The effects of 5.1 sound presentations on the perception of stereoscopic imagery in video games

NASA Astrophysics Data System (ADS)

Cullen, Brian; Galperin, Daniel; Collins, Karen; Hogue, Andrew; Kapralos, Bill

2013-03-01

Stereoscopic 3D (S3D) content in games, film and other audio-visual media has been steadily increasing over the past number of years. However, there are still open, fundamental questions regarding its implementation, particularly as it relates to a multi-modal experience that involves sound and haptics. Research has shown that sound has considerable impact on our perception of 2D phenomena, but very little research has considered how sound may influence stereoscopic 3D. Here we present the results of an experiment that examined the effects of 5.1 surround sound (5.1) and stereo loudspeaker setups on depth perception in relation to S3D imagery within a video game environment. Our aim was to answer the question: "can 5.1 surround sound enhance the participant's perception of depth in the stereoscopic field when compared to traditional stereo sound presentations?" In addition, our study examined how the presence or absence of Doppler frequency shift and frequency fall-off audio effects can also influence depth judgment under these conditions. Results suggest that 5.1 surround sound presentations enhance the apparent depth of stereoscopic imagery when compared to stereo presentations. Results also suggest that the addition of audio effects such as Doppler shift and frequency fall-off filters can influence the apparent depth of S3D objects.

Depth perception based 3D holograms enabled with polarization-independent metasurfaces.

PubMed

Deng, Juan; Li, Zile; Zheng, Guoxing; Tao, Jin; Dai, Qi; Deng, Liangui; He, Ping'an; Deng, Qiling; Mao, Qingzhou

2018-04-30

Metasurfaces consist of dielectric nanobrick arrays with different dimensions in the long and short axes can be used to generate different phase delays, predicting a new way to manipulate an incident beam in the two orthogonal directions separately. Here we demonstrate the concept of depth perception based three-dimensional (3D) holograms with polarization-independent metasurfaces. 4-step dielectric metasurfaces-based fan-out optical elements and holograms operating at 658 nm were designed and simulated. Two different holographic images with high fidelity were generated at the same plane in the far field for different polarization states. One can observe the 3D effect of target objects with polarized glasses. With the advantages of ultracompactness, flexibility and replicability, the polarization-independent metasurfaces open up depth perception based stereoscopic imaging in a holographic way.

Modeling of Depth Cue Integration in Manual Control Tasks

NASA Technical Reports Server (NTRS)

Sweet, Barbara T.; Kaiser, Mary K.; Davis, Wendy

2003-01-01

Psychophysical research has demonstrated that human observers utilize a variety of visual cues to form a perception of three-dimensional depth. However, most of these studies have utilized a passive judgement paradigm, and failed to consider depth-cue integration as a dynamic and task-specific process. In the current study, we developed and experimentally validated a model of manual control of depth that examines how two potential cues (stereo disparity and relative size) are utilized in both first- and second-order active depth control tasks. We found that stereo disparity plays the dominate role for determining depth position, while relative size dominates perception of depth velocity. Stereo disparity also plays a reduced role when made less salient (i.e., when viewing distance is increased). Manual control models predict that position information is sufficient for first-order control tasks, while velocity information is required to perform a second-order control task. Thus, the rules for depth-cue integration in active control tasks are dependent on both task demands and cue quality.

Depth Perception of Surgeons in Minimally Invasive Surgery.

PubMed

Bogdanova, Rositsa; Boulanger, Pierre; Zheng, Bin

2016-10-01

Minimally invasive surgery (MIS) poses visual challenges to the surgeons. In MIS, binocular disparity is not freely available for surgeons, who are required to mentally rebuild the 3-dimensional (3D) patient anatomy from a limited number of monoscopic visual cues. The insufficient depth cues from the MIS environment could cause surgeons to misjudge spatial depth, which could lead to performance errors thus jeopardizing patient safety. In this article, we will first discuss the natural human depth perception by exploring the main depth cues available for surgeons in open procedures. Subsequently, we will reveal what depth cues are lost in MIS and how surgeons compensate for the incomplete depth presentation. Next, we will further expand our knowledge by exploring some of the available solutions for improving depth presentation to surgeons. Here we will review the innovative approaches (multiple 2D camera assembly, shadow introduction) and devices (3D monitors, head-mounted devices, and auto-stereoscopic monitors) for 3D image presentation from the past few years. © The Author(s) 2016.

Clinical Assessment of Stereoacuity and 3-D Stereoscopic Entertainment

PubMed Central

Tidbury, Laurence P.; Black, Robert H.; O’Connor, Anna R.

2015-01-01

Abstract Background/Aims: The perception of compelling depth is often reported in individuals where no clinically measurable stereoacuity is apparent. We aim to investigate the potential cause of this finding by varying the amount of stereopsis available to the subject, and assessing their perception of depth viewing 3-D video clips and a Nintendo 3DS. Methods: Monocular blur was used to vary interocular VA difference, consequently creating 4 levels of measurable binocular deficit from normal stereoacuity to suppression. Stereoacuity was assessed at each level using the TNO, Preschool Randot®, Frisby, the FD2, and Distance Randot®. Subjects also completed an object depth identification task using the Nintendo 3DS, a static 3DTV stereoacuity test, and a 3-D perception rating task of 6 video clips. Results: As intraocular VA differences increased, stereoacuity of the 57 subjects (aged 16–62 years) decreased (eg, 110”, 280”, 340”, and suppression). The ability to correctly identify depth on the Nintendo 3DS remained at 100% until suppression of one eye occurred. The perception of a compelling 3-D effect when viewing the video clips was rated high until suppression of one eye occurred, where the 3-D effect was still reported as fairly evident. Conclusion: If an individual has any level of measurable stereoacuity, the perception of 3-D when viewing stereoscopic entertainment is present. The presence of motion in stereoscopic video appears to provide cues to depth, where static cues are not sufficient. This suggests there is a need for a dynamic test of stereoacuity to be developed, to allow fully informed patient management decisions to be made. PMID:26669421

The visual perception of size and distance.

DOT National Transportation Integrated Search

1962-07-01

The perception of absolute distance has been assumed to be important in the perception of the size of objects and the depth between them. A different hypothesis is proposed. It is asserted that perceived relative size and distance are the primary psy...

Turkish Primary Students' Perceptions of Geography

ERIC Educational Resources Information Center

Senyurt, Secil

2014-01-01

This study provides an in-depth investigation of Turkish primary school students' perceptions of geography. Gender differences in students' perceptions of geography were investigated, including definitions of geography and its field of study. The findings showed that "landforms," "our geographical regions/Turkey,"…

Staying the Distance: Students' Perceptions of Enablers of Transition to Higher Education

ERIC Educational Resources Information Center

Bowles, Angela; Fisher, Ron; McPhail, Ruth; Rosenstreich, Daniela; Dobson, Alexandra

2014-01-01

Students' perceptions during their first semester at university may be critical in the decision to continue or discontinue studies. In this study we consider students' perceptions of what factors enable successful transition to university. Using qualitative research, students' perceptions are obtained by in-depth interviews and focus groups that…

Operational Based Vision Assessment Research: Depth Perception

DTIC Science & Technology

2014-11-01

13-072 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) USAF School of Aerospace Medicine...Aeromedical Research Department 2510 Fifth St. Wright-Patterson AFB, OH 45433-7913 8. PERFORMING ORGANIZATION REPORT NUMBER AFRL-SA-WP-JA-2014...tests are tests of stereopsis, such as the AFVT and AO Vectograph. Others evaluate depth perception with stereo as a contributor to performance , such

Video-Based Method of Quantifying Performance and Instrument Motion During Simulated Phonosurgery

PubMed Central

Conroy, Ellen; Surender, Ketan; Geng, Zhixian; Chen, Ting; Dailey, Seth; Jiang, Jack

2015-01-01

Objectives/Hypothesis To investigate the use of the Video-Based Phonomicrosurgery Instrument Tracking System to collect instrument position data during simulated phonomicrosurgery and calculate motion metrics using these data. We used this system to determine if novice subject motion metrics improved over 1 week of training. Study Design Prospective cohort study. Methods Ten subjects performed simulated surgical tasks once per day for 5 days. Instrument position data were collected and used to compute motion metrics (path length, depth perception, and motion smoothness). Data were analyzed to determine if motion metrics improved with practice time. Task outcome was also determined each day, and relationships between task outcome and motion metrics were used to evaluate the validity of motion metrics as indicators of surgical performance. Results Significant decreases over time were observed for path length (P <.001), depth perception (P <.001), and task outcome (P <.001). No significant change was observed for motion smoothness. Significant relationships were observed between task outcome and path length (P <.001), depth perception (P <.001), and motion smoothness (P <.001). Conclusions Our system can estimate instrument trajectory and provide quantitative descriptions of surgical performance. It may be useful for evaluating phonomicrosurgery performance. Path length and depth perception may be particularly useful indicators. PMID:24737286

Enhancing Motion-In-Depth Perception of Random-Dot Stereograms.

PubMed

Zhang, Di; Nourrit, Vincent; De Bougrenet de la Tocnaye, Jean-Louis

2018-07-01

Random-dot stereograms have been widely used to explore the neural mechanisms underlying binocular vision. Although they are a powerful tool to stimulate motion-in-depth (MID) perception, published results report some difficulties in the capacity to perceive MID generated by random-dot stereograms. The purpose of this study was to investigate whether the performance of MID perception could be improved using an appropriate stimulus design. Sixteen inexperienced observers participated in the experiment. A training session was carried out to improve the accuracy of MID detection before the experiment. Four aspects of stimulus design were investigated: presence of a static reference, background texture, relative disparity, and stimulus contrast. Participants' performance in MID direction discrimination was recorded and compared to evaluate whether varying these factors helped MID perception. Results showed that only the presence of background texture had a significant effect on MID direction perception. This study provides suggestions for the design of 3D stimuli in order to facilitate MID perception.

Six-month-old infants' perception of the hollow face illusion: evidence for a general convexity bias.

PubMed

Corrow, Sherryse L; Mathison, Jordan; Granrud, Carl E; Yonas, Albert

2014-01-01

Corrow, Granrud, Mathison, and Yonas (2011, Perception, 40, 1376-1383) found evidence that 6-month-old infants perceive the hollow face illusion. In the present study we asked whether 6-month-old infants perceive illusory depth reversal for a nonface object and whether infants' perception of the hollow face illusion is affected by mask orientation inversion. In experiment 1 infants viewed a concave bowl, and their reaches were recorded under monocular and binocular viewing conditions. Infants reached to the bowl as if it were convex significantly more often in the monocular than in the binocular viewing condition. These results suggest that infants perceive illusory depth reversal with a nonface stimulus and that the infant visual system has a bias to perceive objects as convex. Infants in experiment 2 viewed a concave face-like mask in upright and inverted orientations. Infants reached to the display as if it were convex more in the monocular than in the binocular condition; however, mask orientation had no effect on reaching. Previous findings that adults' perception of the hollow face illusion is affected by mask orientation inversion have been interpreted as evidence of stored-knowledge influences on perception. However, we found no evidence of such influences in infants, suggesting that their perception of this illusion may not be affected by stored knowledge, and that perceived depth reversal is not face-specific in infants.

Visual Depth from Motion Parallax and Eye Pursuit

PubMed Central

Stroyan, Keith; Nawrot, Mark

2012-01-01

A translating observer viewing a rigid environment experiences “motion parallax,” the relative movement upon the observer’s retina of variously positioned objects in the scene. This retinal movement of images provides a cue to the relative depth of objects in the environment, however retinal motion alone cannot mathematically determine relative depth of the objects. Visual perception of depth from lateral observer translation uses both retinal image motion and eye movement. In (Nawrot & Stroyan, 2009, Vision Res. 49, p.1969) we showed mathematically that the ratio of the rate of retinal motion over the rate of smooth eye pursuit mathematically determines depth relative to the fixation point in central vision. We also reported on psychophysical experiments indicating that this ratio is the important quantity for perception. Here we analyze the motion/pursuit cue for the more general, and more complicated, case when objects are distributed across the horizontal viewing plane beyond central vision. We show how the mathematical motion/pursuit cue varies with different points across the plane and with time as an observer translates. If the time varying retinal motion and smooth eye pursuit are the only signals used for this visual process, it is important to know what is mathematically possible to derive about depth and structure. Our analysis shows that the motion/pursuit ratio determines an excellent description of depth and structure in these broader stimulus conditions, provides a detailed quantitative hypothesis of these visual processes for the perception of depth and structure from motion parallax, and provides a computational foundation to analyze the dynamic geometry of future experiments. PMID:21695531

Audio–visual interactions for motion perception in depth modulate activity in visual area V3A

PubMed Central

Ogawa, Akitoshi; Macaluso, Emiliano

2013-01-01

Multisensory signals can enhance the spatial perception of objects and events in the environment. Changes of visual size and auditory intensity provide us with the main cues about motion direction in depth. However, frequency changes in audition and binocular disparity in vision also contribute to the perception of motion in depth. Here, we presented subjects with several combinations of auditory and visual depth-cues to investigate multisensory interactions during processing of motion in depth. The task was to discriminate the direction of auditory motion in depth according to increasing or decreasing intensity. Rising or falling auditory frequency provided an additional within-audition cue that matched or did not match the intensity change (i.e. intensity-frequency (IF) “matched vs. unmatched” conditions). In two-thirds of the trials, a task-irrelevant visual stimulus moved either in the same or opposite direction of the auditory target, leading to audio–visual “congruent vs. incongruent” between-modalities depth-cues. Furthermore, these conditions were presented either with or without binocular disparity. Behavioral data showed that the best performance was observed in the audio–visual congruent condition with IF matched. Brain imaging results revealed maximal response in visual area V3A when all cues provided congruent and reliable depth information (i.e. audio–visual congruent, IF-matched condition including disparity cues). Analyses of effective connectivity revealed increased coupling from auditory cortex to V3A specifically in audio–visual congruent trials. We conclude that within- and between-modalities cues jointly contribute to the processing of motion direction in depth, and that they do so via dynamic changes of connectivity between visual and auditory cortices. PMID:23333414

Volumetric 3D display with multi-layered active screens for enhanced the depth perception (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kim, Hak-Rin; Park, Min-Kyu; Choi, Jun-Chan; Park, Ji-Sub; Min, Sung-Wook

2016-09-01

Three-dimensional (3D) display technology has been studied actively because it can offer more realistic images compared to the conventional 2D display. Various psychological factors such as accommodation, binocular parallax, convergence and motion parallax are used to recognize a 3D image. For glass-type 3D displays, they use only the binocular disparity in 3D depth cues. However, this method cause visual fatigue and headaches due to accommodation conflict and distorted depth perception. Thus, the hologram and volumetric display are expected to be an ideal 3D display. Holographic displays can represent realistic images satisfying the entire factors of depth perception. But, it require tremendous amount of data and fast signal processing. The volumetric 3D displays can represent images using voxel which is a physical volume. However, it is required for large data to represent the depth information on voxel. In order to simply encode 3D information, the compact type of depth fused 3D (DFD) display, which can create polarization distributed depth map (PDDM) image having both 2D color image and depth image is introduced. In this paper, a new volumetric 3D display system is shown by using PDDM image controlled by polarization controller. In order to introduce PDDM image, polarization states of the light through spatial light modulator (SLM) was analyzed by Stokes parameter depending on the gray level. Based on the analysis, polarization controller is properly designed to convert PDDM image into sectioned depth images. After synchronizing PDDM images with active screens, we can realize reconstructed 3D image. Acknowledgment This work was supported by `The Cross-Ministry Giga KOREA Project' grant from the Ministry of Science, ICT and Future Planning, Korea

Teachers' Perception of Social Justice in Mathematics Classrooms

ERIC Educational Resources Information Center

Panthi, Ram Krishna; Luitel, Bal Chandra; Belbase, Shashidhar

2017-01-01

The purpose of this study was to explore mathematics teachers' perception of social justice in mathematics classrooms. We applied interpretive qualitative method for data collection, analysis, and interpretation through iterative process. We administered in-depth semi-structured interviews to capture the perceptions of three mathematics teachers…

Teachers' Perception of Social Justice in Mathematics Classrooms

ERIC Educational Resources Information Center

Panthi, Ram Krishna; Luitel, Bal Chandra; Belbase, Shashidhar

2018-01-01

The purpose of this study was to explore mathematics teachers' perception of social justice in mathematics classrooms. We applied interpretive qualitative method for data collection, analysis, and interpretation through iterative process. We administered in-depth semi-structured interviews to capture the perceptions of three mathematics teachers…

Neural Integration of Information Specifying Human Structure from Form, Motion, and Depth

PubMed Central

Jackson, Stuart; Blake, Randolph

2010-01-01

Recent computational models of biological motion perception operate on ambiguous two-dimensional representations of the body (e.g., snapshots, posture templates) and contain no explicit means for disambiguating the three-dimensional orientation of a perceived human figure. Are there neural mechanisms in the visual system that represent a moving human figure’s orientation in three dimensions? To isolate and characterize the neural mechanisms mediating perception of biological motion, we used an adaptation paradigm together with bistable point-light (PL) animations whose perceived direction of heading fluctuates over time. After exposure to a PL walker with a particular stereoscopically defined heading direction, observers experienced a consistent aftereffect: a bistable PL walker, which could be perceived in the adapted orientation or reversed in depth, was perceived predominantly reversed in depth. A phase-scrambled adaptor produced no aftereffect, yet when adapting and test walkers differed in size or appeared on opposite sides of fixation aftereffects did occur. Thus, this heading direction aftereffect cannot be explained by local, disparity-specific motion adaptation, and the properties of scale and position invariance imply higher-level origins of neural adaptation. Nor is disparity essential for producing adaptation: when suspended on top of a stereoscopically defined, rotating globe, a context-disambiguated “globetrotter” was sufficient to bias the bistable walker’s direction, as were full-body adaptors. In sum, these results imply that the neural signals supporting biomotion perception integrate information on the form, motion, and three-dimensional depth orientation of the moving human figure. Models of biomotion perception should incorporate mechanisms to disambiguate depth ambiguities in two-dimensional body representations. PMID:20089892

Promoting Instructional Improvement or Resistance? A Comparative Study of Teachers' Perceptions of Teacher Evaluation Policy in Korea and the USA

ERIC Educational Resources Information Center

Kim, Jihyun; Youngs, Peter

2016-01-01

This study draws on institutional theory to examine teachers' and principals' perceptions of new teacher evaluation policies, factors that influence such perceptions and how such perceptions shape the implementation of the policies in Seoul (Korea) and Michigan (USA). The study featured in-depth interviews of 11 elementary school teachers and 4…

The role of eye movements in depth from motion parallax during infancy

PubMed Central

Nawrot, Elizabeth; Nawrot, Mark

2013-01-01

Motion parallax is a motion-based, monocular depth cue that uses an object's relative motion and velocity as a cue to relative depth. In adults, and in monkeys, a smooth pursuit eye movement signal is used to disambiguate the depth-sign provided by these relative motion cues. The current study investigates infants' perception of depth from motion parallax and the development of two oculomotor functions, smooth pursuit and the ocular following response (OFR) eye movements. Infants 8 to 20 weeks of age were presented with three tasks in a single session: depth from motion parallax, smooth pursuit tracking, and OFR to translation. The development of smooth pursuit was significantly related to age, as was sensitivity to motion parallax. OFR eye movements also corresponded to both age and smooth pursuit gain, with groups of infants demonstrating asymmetric function in both types of eye movements. These results suggest that the development of the eye movement system may play a crucial role in the sensitivity to depth from motion parallax in infancy. Moreover, describing the development of these oculomotor functions in relation to depth perception may aid in the understanding of certain visual dysfunctions. PMID:24353309

Optimal combination of illusory and luminance-defined 3-D surfaces: A role for ambiguity.

PubMed

Hartle, Brittney; Wilcox, Laurie M; Murray, Richard F

2018-04-01

The shape of the illusory surface in stereoscopic Kanizsa figures is determined by the interpolation of depth from the luminance edges of adjacent inducing elements. Despite ambiguity in the position of illusory boundaries, observers reliably perceive a coherent three-dimensional (3-D) surface. However, this ambiguity may contribute additional uncertainty to the depth percept beyond what is expected from measurement noise alone. We evaluated the intrinsic ambiguity of illusory boundaries by using a cue-combination paradigm to measure the reliability of depth percepts elicited by stereoscopic illusory surfaces. We assessed the accuracy and precision of depth percepts using 3-D Kanizsa figures relative to luminance-defined surfaces. The location of the surface peak was defined by illusory boundaries, luminance-defined edges, or both. Accuracy and precision were assessed using a depth-discrimination paradigm. A maximum likelihood linear cue combination model was used to evaluate the relative contribution of illusory and luminance-defined signals to the perceived depth of the combined surface. Our analysis showed that the standard deviation of depth estimates was consistent with an optimal cue combination model, but the points of subjective equality indicated that observers consistently underweighted the contribution of illusory boundaries. This systematic underweighting may reflect a combination rule that attributes additional intrinsic ambiguity to the location of the illusory boundary. Although previous studies show that illusory and luminance-defined contours share many perceptual similarities, our model suggests that ambiguity plays a larger role in the perceptual representation of illusory contours than of luminance-defined contours.

Modeling depth from motion parallax with the motion/pursuit ratio

PubMed Central

Nawrot, Mark; Ratzlaff, Michael; Leonard, Zachary; Stroyan, Keith

2014-01-01

The perception of unambiguous scaled depth from motion parallax relies on both retinal image motion and an extra-retinal pursuit eye movement signal. The motion/pursuit ratio represents a dynamic geometric model linking these two proximal cues to the ratio of depth to viewing distance. An important step in understanding the visual mechanisms serving the perception of depth from motion parallax is to determine the relationship between these stimulus parameters and empirically determined perceived depth magnitude. Observers compared perceived depth magnitude of dynamic motion parallax stimuli to static binocular disparity comparison stimuli at three different viewing distances, in both head-moving and head-stationary conditions. A stereo-viewing system provided ocular separation for stereo stimuli and monocular viewing of parallax stimuli. For each motion parallax stimulus, a point of subjective equality (PSE) was estimated for the amount of binocular disparity that generates the equivalent magnitude of perceived depth from motion parallax. Similar to previous results, perceived depth from motion parallax had significant foreshortening. Head-moving conditions produced even greater foreshortening due to the differences in the compensatory eye movement signal. An empirical version of the motion/pursuit law, termed the empirical motion/pursuit ratio, which models perceived depth magnitude from these stimulus parameters, is proposed. PMID:25339926

Segregation of Form, Color, Movement, and Depth: Anatomy, Physiology, and Perception

NASA Astrophysics Data System (ADS)

Livingstone, Margaret; Hubel, David

1988-05-01

Anatomical and physiological observations in monkeys indicate that the primate visual system consists of several separate and independent subdivisions that analyze different aspects of the same retinal image: cells in cortical visual areas 1 and 2 and higher visual areas are segregated into three interdigitating subdivisions that differ in their selectivity for color, stereopsis, movement, and orientation. The pathways selective for form and color seem to be derived mainly from the parvocellular geniculate subdivisions, the depth- and movement-selective components from the magnocellular. At lower levels, in the retina and in the geniculate, cells in these two subdivisions differ in their color selectivity, contrast sensitivity, temporal properties, and spatial resolution. These major differences in the properties of cells at lower levels in each of the subdivisions led to the prediction that different visual functions, such as color, depth, movement, and form perception, should exhibit corresponding differences. Human perceptual experiments are remarkably consistent with these predictions. Moreover, perceptual experiments can be designed to ask which subdivisions of the system are responsible for particular visual abilities, such as figure/ground discrimination or perception of depth from perspective or relative movement--functions that might be difficult to deduce from single-cell response properties.

A novel rotational matrix and translation vector algorithm: geometric accuracy for augmented reality in oral and maxillofacial surgeries.

PubMed

Murugesan, Yahini Prabha; Alsadoon, Abeer; Manoranjan, Paul; Prasad, P W C

2018-06-01

Augmented reality-based surgeries have not been successfully implemented in oral and maxillofacial areas due to limitations in geometric accuracy and image registration. This paper aims to improve the accuracy and depth perception of the augmented video. The proposed system consists of a rotational matrix and translation vector algorithm to reduce the geometric error and improve the depth perception by including 2 stereo cameras and a translucent mirror in the operating room. The results on the mandible/maxilla area show that the new algorithm improves the video accuracy by 0.30-0.40 mm (in terms of overlay error) and the processing rate to 10-13 frames/s compared to 7-10 frames/s in existing systems. The depth perception increased by 90-100 mm. The proposed system concentrates on reducing the geometric error. Thus, this study provides an acceptable range of accuracy with a shorter operating time, which provides surgeons with a smooth surgical flow. Copyright © 2018 John Wiley & Sons, Ltd.

The visual perception of spatial extent.

DOT National Transportation Integrated Search

1963-09-01

This study was concerned with the manner in which perceived depth and perceived frontoparallel size varied with physical distance and hence with each other. An equation expressing the relation between perceived frontoparallel size and physical depth ...

Chromatic assimilation unaffected by perceived depth of inducing light.

PubMed

Shevell, Steven K; Cao, Dingcai

2004-01-01

Chromatic assimilation is a shift toward the color of nearby light. Several studies conclude that a neural process contributes to assimilation but the neural locus remains in question. Some studies posit a peripheral process, such as retinal receptive-field organization, while others claim the neural mechanism follows depth perception, figure/ground segregation, or perceptual grouping. The experiments here tested whether assimilation depends on a neural process that follows stereoscopic depth perception. By introducing binocular disparity, the test field judged in color was made to appear in a different depth plane than the light that induced assimilation. The chromaticity and spatial frequency of the inducing light, and the chromaticity of the test light, were varied. Chromatic assimilation was found with all inducing-light sizes and chromaticities, but the magnitude of assimilation did not depend on the perceived relative depth planes of the test and inducing fields. We found no evidence to support the view that chromatic assimilation depends on a neural process that follows binocular combination of the two eyes' signals.

Lesions to right posterior parietal cortex impair visual depth perception from disparity but not motion cues

PubMed Central

Leopold, David A.; Humphreys, Glyn W.; Welchman, Andrew E.

2016-01-01

The posterior parietal cortex (PPC) is understood to be active when observers perceive three-dimensional (3D) structure. However, it is not clear how central this activity is in the construction of 3D spatial representations. Here, we examine whether PPC is essential for two aspects of visual depth perception by testing patients with lesions affecting this region. First, we measured subjects' ability to discriminate depth structure in various 3D surfaces and objects using binocular disparity. Patients with lesions to right PPC (N = 3) exhibited marked perceptual deficits on these tasks, whereas those with left hemisphere lesions (N = 2) were able to reliably discriminate depth as accurately as control subjects. Second, we presented an ambiguous 3D stimulus defined by structure from motion to determine whether PPC lesions influence the rate of bistable perceptual alternations. Patients' percept durations for the 3D stimulus were generally within a normal range, although the two patients with bilateral PPC lesions showed the fastest perceptual alternation rates in our sample. Intermittent stimulus presentation reduced the reversal rate similarly across subjects. Together, the results suggest that PPC plays a causal role in both inferring and maintaining the perception of 3D structure with stereopsis supported primarily by the right hemisphere, but do not lend support to the view that PPC is a critical contributor to bistable perceptual alternations. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269606

Knowledge Worker Perceptions of Telework Policy in the New York Metropolitan Area: A Qualitative Descriptive Study

ERIC Educational Resources Information Center

Slaughter, Sandra Lorraine Hawks

2013-01-01

This qualitative descriptive case study, "Knowledge Worker Perceptions of Telework in the New York Metropolitan Area," was conducted to explore the perceptions of knowledge workers who commute to a physical workplace in the New York Metropolitan area (NYMA). In-depth interviews were conducted with fourteen NYMA commuters who are…

Student Perceptions of Service Quality in a Multi-Campus Higher Education System in Spain

ERIC Educational Resources Information Center

Gallifa, Josep; Batalle, Pere

2010-01-01

Purpose: This paper aims to present an in-depth case study with student perceptions of service quality, discussing the relevance of these perceptions for the important issue of quality improvement in higher education. Design/methodology/approach: The paper presents institutional research carried out in a multi-campus system in Spain made up of…

Stereoscopic Perception of Women in Real and Virtual Environments: A Study towards Educational Neuroscience

ERIC Educational Resources Information Center

Zacharis, Georgios S.; Mikropoulos, Tassos A.; Priovolou, Chryssi

2013-01-01

Previous studies report the involvement of specific brain activation in stereoscopic vision and the perception of depth information. This work presents the first comparative results of adult women on the effects of stereoscopic perception in three different static environments; a real, a two dimensional (2D) and a stereoscopic three dimensional…

Depth Perception in Space Artist Concept

NASA Image and Video Library

2007-05-30

This artist concept shows how astronomers use the unique orbit of NASA Spitzer Space Telescope and a depth-perceiving trick called parallax to determine the distance of dark planets, black holes and failed stars that lurk invisibly among us.

Integration time for the perception of depth from motion parallax.

PubMed

Nawrot, Mark; Stroyan, Keith

2012-04-15

The perception of depth from relative motion is believed to be a slow process that "builds-up" over a period of observation. However, in the case of motion parallax, the potential accuracy of the depth estimate suffers as the observer translates during the viewing period. Our recent quantitative model for the perception of depth from motion parallax proposes that relative object depth (d) can be determined from retinal image motion (dθ/dt), pursuit eye movement (dα/dt), and fixation distance (f) by the formula: d/f≈dθ/dα. Given the model's dynamics, it is important to know the integration time required by the visual system to recover dα and dθ, and then estimate d. Knowing the minimum integration time reveals the incumbent error in this process. A depth-phase discrimination task was used to determine the time necessary to perceive depth-sign from motion parallax. Observers remained stationary and viewed a briefly translating random-dot motion parallax stimulus. Stimulus duration varied between trials. Fixation on the translating stimulus was monitored and enforced with an eye-tracker. The study found that relative depth discrimination can be performed with presentations as brief as 16.6 ms, with only two stimulus frames providing both retinal image motion and the stimulus window motion for pursuit (mean range=16.6-33.2 ms). This was found for conditions in which, prior to stimulus presentation, the eye was engaged in ongoing pursuit or the eye was stationary. A large high-contrast masking stimulus disrupted depth-discrimination for stimulus presentations less than 70-75 ms in both pursuit and stationary conditions. This interval might be linked to ocular-following response eye-movement latencies. We conclude that neural mechanisms serving depth from motion parallax generate a depth estimate much more quickly than previously believed. We propose that additional sluggishness might be due to the visual system's attempt to determine the maximum dθ/dα ratio for a selection of points on a complicated stimulus. Copyright © 2012 Elsevier Ltd. All rights reserved.

The right view from the wrong location: depth perception in stereoscopic multi-user virtual environments.

PubMed

Pollock, Brice; Burton, Melissa; Kelly, Jonathan W; Gilbert, Stephen; Winer, Eliot

2012-04-01

Stereoscopic depth cues improve depth perception and increase immersion within virtual environments (VEs). However, improper display of these cues can distort perceived distances and directions. Consider a multi-user VE, where all users view identical stereoscopic images regardless of physical location. In this scenario, cues are typically customized for one "leader" equipped with a head-tracking device. This user stands at the center of projection (CoP) and all other users ("followers") view the scene from other locations and receive improper depth cues. This paper examines perceived depth distortion when viewing stereoscopic VEs from follower perspectives and the impact of these distortions on collaborative spatial judgments. Pairs of participants made collaborative depth judgments of virtual shapes viewed from the CoP or after displacement forward or backward. Forward and backward displacement caused perceived depth compression and expansion, respectively, with greater compression than expansion. Furthermore, distortion was less than predicted by a ray-intersection model of stereo geometry. Collaboration times were significantly longer when participants stood at different locations compared to the same location, and increased with greater perceived depth discrepancy between the two viewing locations. These findings advance our understanding of spatial distortions in multi-user VEs, and suggest a strategy for reducing distortion.

Improved depth perception with three-dimensional auxiliary display and computer generated three-dimensional panoramic overviews in robot-assisted laparoscopy

PubMed Central

Wieringa, Fokko P.; Bouma, Henri; Eendebak, Pieter T.; van Basten, Jean-Paul A.; Beerlage, Harrie P.; Smits, Geert A. H. J.; Bos, Jelte E.

2014-01-01

Abstract. In comparison to open surgery, endoscopic surgery offers impaired depth perception and narrower field-of-view. To improve depth perception, the Da Vinci robot offers three-dimensional (3-D) video on the console for the surgeon but not for assistants, although both must collaborate. We improved the shared perception of the whole surgical team by connecting live 3-D monitors to all three available Da Vinci generations, probed user experience after two years by questionnaire, and compared time measurements of a predefined complex interaction task performed with a 3-D monitor versus two-dimensional. Additionally, we investigated whether the complex mental task of reconstructing a 3-D overview from an endoscopic video can be performed by a computer and shared among users. During the study, 925 robot-assisted laparoscopic procedures were performed in three hospitals, including prostatectomies, cystectomies, and nephrectomies. Thirty-one users participated in our questionnaire. Eighty-four percent preferred 3-D monitors and 100% reported spatial-perception improvement. All participating urologists indicated quicker performance of tasks requiring delicate collaboration (e.g., clip placement) when assistants used 3-D monitors. Eighteen users participated in a timing experiment during a delicate cooperation task in vitro. Teamwork was significantly (40%) faster with the 3-D monitor. Computer-generated 3-D reconstructions from recordings offered very wide interactive panoramas with educational value, although the present embodiment is vulnerable to movement artifacts. PMID:26158026

False Color Terrain Model of Phoenix Workspace

NASA Image and Video Library

2008-05-28

This is a terrain model of Phoenix Robotic Arm workspace. It has been color coded by depth with a lander model for context. The model has been derived using images from the depth perception feature from Phoenix Surface Stereo Imager SSI.

A novel virtual reality simulation for hemostasis in a brain surgical cavity: perceived utility for visuomotor skills in current and aspiring neurosurgery residents.

PubMed

Gasco, Jaime; Patel, Achal; Luciano, Cristian; Holbrook, Thomas; Ortega-Barnett, Juan; Kuo, Yong-Fang; Rizzi, Silvio; Kania, Patrick; Banerjee, Pat; Roitberg, Ben Z

2013-12-01

To understand the perceived utility of a novel simulator to improve operative skill, eye-hand coordination, and depth perception. We used the ImmersiveTouch simulation platform (ImmersiveTouch, Inc., Chicago, Illinois, USA) in two U.S. Accreditation Council for Graduate Medical Education-accredited neurosurgical training programs: the University of Chicago and the University of Texas Medical Branch. A total of 54 trainees participated in the study, which consisted of 14 residents (group A), 20 senior medical students who were neurosurgery candidates (group B), and 20 junior medical students (group C). The participants performed a simulation task that established bipolar hemostasis in a virtual brain cavity and provided qualitative feedback regarding perceived benefits in eye-hand coordination, depth perception, and potential to assist in improving operating skills. The perceived ability of the simulator to positively influence skills judged by the three groups: group A, residents; group B, senior medical students; and group C, junior medical students was, respectively, 86%, 100%, and 100% for eye-hand coordination; 86%, 100%, and 95% for depth perception; and 79%, 100%, and 100% for surgical skills in the operating room. From all groups, 96.2% found the simulation somewhat or very useful to improve eye-hand coordination, and 94% considered it beneficial to improve depth perception and operating room skills. This simulation module may be suitable for resident training, as well as for the development of career interest and skill acquisition; however, validation for this type of simulation needs to be further developed. Copyright © 2013 Elsevier Inc. All rights reserved.

Problems in depth perception : perceived size and distance of familiar objects.

DOT National Transportation Integrated Search

1966-06-01

Judgments of the distance of familiar objects, especially other aircraft, are critical aspects of flight safety. In this study, the perception of distance as a function of the retinal size of a familiar object was investigated by simulating a station...

An Initial Exploration into a Time of Change: Teacher Perceptions of Their Profession in the New Millennium.

ERIC Educational Resources Information Center

Jones, Tamara

This paper explores the perceptions of three rural secondary school teachers in the Riverina area of New South Wales, Australia. In-depth interviews were conducted with three secondary teachers: three male teachers aged 25, 32, and 60. The original objective of the grounded theory study was to examine the teachers' perceptions about the state's…

Mitigation of wildfire risk by homeowners

Treesearch

Hannah Brenkert; Patricia Champ; Nicholas Flores

2005-01-01

In-depth interviews conducted with homeowners in Larimer County's Wildland-Urban Interface revealed that homeowners face difficult decisions regarding the implementation of wildfire mitigation measures. Perceptions of wildfire mitigation options may be as important as perceptions of wildfire risk in determining likelihood of implementation. These mitigation...

Monocular Depth Perception and Robotic Grasping of Novel Objects

DTIC Science & Technology

2009-06-01

resulting algorithm is able to learn monocular vision cues that accurately estimate the relative depths of obstacles in a scene. Reinforcement learning ... learning still make sense in these settings? Since many of the cues that are useful for estimating depth can be re-created in synthetic images, we...supervised learning approach to this problem, and use a Markov Random Field (MRF) to model the scene depth as a function of the image features. We show

Cross-matching: a modified cross-correlation underlying threshold energy model and match-based depth perception

PubMed Central

Doi, Takahiro; Fujita, Ichiro

2014-01-01

Three-dimensional visual perception requires correct matching of images projected to the left and right eyes. The matching process is faced with an ambiguity: part of one eye's image can be matched to multiple parts of the other eye's image. This stereo correspondence problem is complicated for random-dot stereograms (RDSs), because dots with an identical appearance produce numerous potential matches. Despite such complexity, human subjects can perceive a coherent depth structure. A coherent solution to the correspondence problem does not exist for anticorrelated RDSs (aRDSs), in which luminance contrast is reversed in one eye. Neurons in the visual cortex reduce disparity selectivity for aRDSs progressively along the visual processing hierarchy. A disparity-energy model followed by threshold nonlinearity (threshold energy model) can account for this reduction, providing a possible mechanism for the neural matching process. However, the essential computation underlying the threshold energy model is not clear. Here, we propose that a nonlinear modification of cross-correlation, which we term “cross-matching,” represents the essence of the threshold energy model. We placed half-wave rectification within the cross-correlation of the left-eye and right-eye images. The disparity tuning derived from cross-matching was attenuated for aRDSs. We simulated a psychometric curve as a function of graded anticorrelation (graded mixture of aRDS and normal RDS); this simulated curve reproduced the match-based psychometric function observed in human near/far discrimination. The dot density was 25% for both simulation and observation. We predicted that as the dot density increased, the performance for aRDSs should decrease below chance (i.e., reversed depth), and the level of anticorrelation that nullifies depth perception should also decrease. We suggest that cross-matching serves as a simple computation underlying the match-based disparity signals in stereoscopic depth perception. PMID:25360107

Applications of just-noticeable depth difference model in joint multiview video plus depth coding

NASA Astrophysics Data System (ADS)

Liu, Chao; An, Ping; Zuo, Yifan; Zhang, Zhaoyang

2014-10-01

A new multiview just-noticeable-depth-difference(MJNDD) Model is presented and applied to compress the joint multiview video plus depth. Many video coding algorithms remove spatial and temporal redundancies and statistical redundancies but they are not capable of removing the perceptual redundancies. Since the final receptor of video is the human eyes, we can remove the perception redundancy to gain higher compression efficiency according to the properties of human visual system (HVS). Traditional just-noticeable-distortion (JND) model in pixel domain contains luminance contrast and spatial-temporal masking effects, which describes the perception redundancy quantitatively. Whereas HVS is very sensitive to depth information, a new multiview-just-noticeable-depth-difference(MJNDD) model is proposed by combining traditional JND model with just-noticeable-depth-difference (JNDD) model. The texture video is divided into background and foreground areas using depth information. Then different JND threshold values are assigned to these two parts. Later the MJNDD model is utilized to encode the texture video on JMVC. When encoding the depth video, JNDD model is applied to remove the block artifacts and protect the edges. Then we use VSRS3.5 (View Synthesis Reference Software) to generate the intermediate views. Experimental results show that our model can endure more noise and the compression efficiency is improved by 25.29 percent at average and by 54.06 percent at most compared to JMVC while maintaining the subject quality. Hence it can gain high compress ratio and low bit rate.

Experiencing Technology Integration in Education: Children's Perceptions

ERIC Educational Resources Information Center

Baytak, Ahmet; Tarman, Bülent; Ayas, Cemalettin

2011-01-01

The purpose of this phenomenological study was to explore the experiences of six children using technologies in their education. Data were collected via in-depth interviews, classroom observations, and home observations. The results showed that students have common perceptions toward their experience with technology integration. Furthermore, the…

Student-Athlete Wellbeing and Persistence: An In-Depth Look at Student-Athlete Perceptions

ERIC Educational Resources Information Center

Kamusoko, Sibongile D.; Pemberton, Cynthia Lee A.

2012-01-01

This study investigated student-athlete perceptions of wellbeing, delimited to satisfaction regarding Athletic Department Policies and Practices, Educational Characteristics, Institutional Facilities and Services, and intent to academically persist. The study employed quantitative and qualitative data queries. This paper reports emergent findings…

Short-Term Fun or Long-Term Gain: A Mixed Methods Empirical Investigation into Perceptions of Truancy among Non-Truants in Flanders

ERIC Educational Resources Information Center

Keppens, G.; Spruyt, B.

2015-01-01

The purpose of the present study is to explore non-truanting youngsters' perceptions of truants and truancy. In-depth qualitative interviews (N: 8) are used to explore inductively the perceptions of truancy among non-truanting pupils in secondary education in Flanders (the Dutch-speaking part of Belgium). We use survey analysis (N: 3314) to assess…

Evaluating methods for controlling depth perception in stereoscopic cinematography

NASA Astrophysics Data System (ADS)

Sun, Geng; Holliman, Nick

2009-02-01

Existing stereoscopic imaging algorithms can create static stereoscopic images with perceived depth control function to ensure a compelling 3D viewing experience without visual discomfort. However, current algorithms do not normally support standard Cinematic Storytelling techniques. These techniques, such as object movement, camera motion, and zooming, can result in dynamic scene depth change within and between a series of frames (shots) in stereoscopic cinematography. In this study, we empirically evaluate the following three types of stereoscopic imaging approaches that aim to address this problem. (1) Real-Eye Configuration: set camera separation equal to the nominal human eye interpupillary distance. The perceived depth on the display is identical to the scene depth without any distortion. (2) Mapping Algorithm: map the scene depth to a predefined range on the display to avoid excessive perceived depth. A new method that dynamically adjusts the depth mapping from scene space to display space is presented in addition to an existing fixed depth mapping method. (3) Depth of Field Simulation: apply Depth of Field (DOF) blur effect to stereoscopic images. Only objects that are inside the DOF are viewed in full sharpness. Objects that are far away from the focus plane are blurred. We performed a human-based trial using the ITU-R BT.500-11 Recommendation to compare the depth quality of stereoscopic video sequences generated by the above-mentioned imaging methods. Our results indicate that viewers' practical 3D viewing volumes are different for individual stereoscopic displays and viewers can cope with much larger perceived depth range in viewing stereoscopic cinematography in comparison to static stereoscopic images. Our new dynamic depth mapping method does have an advantage over the fixed depth mapping method in controlling stereo depth perception. The DOF blur effect does not provide the expected improvement for perceived depth quality control in 3D cinematography. We anticipate the results will be of particular interest to 3D filmmaking and real time computer games.

Occupants' Perceptions of Amenity and Efficiency for Verification of Spatial Design Adequacy.

PubMed

Lee, Sangwon; Wohn, Kwangyun

2016-01-14

The best spatial design condition to satisfy the occupancy needs of amenity and efficiency is determined through analyzing the spatial design adequacy (SDA). In this study, the relationship between the space design elements and space on future occupants' perception are analyzed. The thirty-three participants reported their self-evaluated SDA that describes the quality of eight alternative housing living rooms with different spatial factors. The occupants were guided through the perception processing elaboration in order for them to evaluate the actual perception in the real space. The findings demonstrated that the spatial size (e.g., width, depth, and height) is significantly correlated with the overall satisfaction of amenity. It is also found that the spatial shape (e.g., the width-to-depth ratio, the height-to-area ratio, and room shape) may significantly influence the overall satisfaction of efficiency. The findings also demonstrate that the causal relationship between the spatial factors and space is clearly present in the occupants' perception, reflecting the time-sequential characteristics of the actual experience divided into amenity and efficiency. This result indicates that the correlation between the spatial factors and space of SDA under the occupants' perception processing elaboration can be a useful guide to predict the occupancy satisfaction of amenity and efficiency in real spaces.

Occupants’ Perceptions of Amenity and Efficiency for Verification of Spatial Design Adequacy

PubMed Central

Lee, Sangwon; Wohn, Kwangyun

2016-01-01

The best spatial design condition to satisfy the occupancy needs of amenity and efficiency is determined through analyzing the spatial design adequacy (SDA). In this study, the relationship between the space design elements and space on future occupants’ perception are analyzed. The thirty-three participants reported their self-evaluated SDA that describes the quality of eight alternative housing living rooms with different spatial factors. The occupants were guided through the perception processing elaboration in order for them to evaluate the actual perception in the real space. The findings demonstrated that the spatial size (e.g., width, depth, and height) is significantly correlated with the overall satisfaction of amenity. It is also found that the spatial shape (e.g., the width-to-depth ratio, the height-to-area ratio, and room shape) may significantly influence the overall satisfaction of efficiency. The findings also demonstrate that the causal relationship between the spatial factors and space is clearly present in the occupants’ perception, reflecting the time-sequential characteristics of the actual experience divided into amenity and efficiency. This result indicates that the correlation between the spatial factors and space of SDA under the occupants’ perception processing elaboration can be a useful guide to predict the occupancy satisfaction of amenity and efficiency in real spaces. PMID:26784211

Augmented Reality Imaging System: 3D Viewing of a Breast Cancer.

PubMed

Douglas, David B; Boone, John M; Petricoin, Emanuel; Liotta, Lance; Wilson, Eugene

2016-01-01

To display images of breast cancer from a dedicated breast CT using Depth 3-Dimensional (D3D) augmented reality. A case of breast cancer imaged using contrast-enhanced breast CT (Computed Tomography) was viewed with the augmented reality imaging, which uses a head display unit (HDU) and joystick control interface. The augmented reality system demonstrated 3D viewing of the breast mass with head position tracking, stereoscopic depth perception, focal point convergence and the use of a 3D cursor and joy-stick enabled fly through with visualization of the spiculations extending from the breast cancer. The augmented reality system provided 3D visualization of the breast cancer with depth perception and visualization of the mass's spiculations. The augmented reality system should be further researched to determine the utility in clinical practice.

Students' Perceptions of a "Quality" Advisory Relationship

ERIC Educational Resources Information Center

Halbert, Kelsey

2015-01-01

The current research education context in Australia is one of increased pressures for timely completion with a spotlight on the scope and depth of training and a profound increase in enrolments. These factors inevitably shape the supervision experiences of doctoral candidates. This paper discusses student perceptions of supervision. Supervision is…

Perceptions of Learning among Swiss Watch Managers

ERIC Educational Resources Information Center

Tajeddini, Kayhan

2009-01-01

Purpose: This paper aims to explore managers' perceptions of learning within a sample of Swiss watch firms. Design/methodology/approach: A purposeful (judgmental) stratified sampling method was employed, where in-depth interviews with 13 marketing managers and owners were carried out over a three-month period. Meaning units (MUs) were abstracted,…

Teachers' Perception, Interpretation, and Decision-Making: A Systematic Review of Empirical Mathematics Education Research

ERIC Educational Resources Information Center

Stahnke, Rebekka; Schueler, Sven; Roesken-Winter, Bettina

2016-01-01

Research in mathematics education has investigated teachers' professional knowledge in depth, comprising two different approaches: a cognitive and a situated perspective. Linking these two perspectives leads to addressing situation-specific skills such as perception, interpretation and decision-making, indicative of revealing a teacher's knowledge…

"Some Kind of Weird, Evil Experiment": Student Perceptions of Peer Assessment

ERIC Educational Resources Information Center

Patton, Chloe

2012-01-01

This paper explores the attitudes and perceptions of three cohorts of Australian humanities and social science undergraduate students towards peer assessment. It seeks to gain a deeper understanding of local dissatisfaction with peer assessment through an in-depth analysis of students' contributions to focus group discussions. Responding to…

[Comparative analysis of light sensitivity, depth and motion perception in animals and humans].

PubMed

Schaeffel, F

2017-11-01

This study examined how humans perform regarding light sensitivity, depth perception and motion vision in comparison to various animals. The parameters that limit the performance of the visual system for these different functions were examined. This study was based on literature studies (search in PubMed) and own results. Light sensitivity is limited by the brightness of the retinal image, which in turn is determined by the f‑number of the eye. Furthermore, it is limited by photon noise, thermal decay of rhodopsin, noise in the phototransduction cascade and neuronal processing. In invertebrates, impressive optical tricks have been developed to increase the number of photons reaching the photoreceptors. Furthermore, the spontaneous decay of the photopigment is lower in invertebrates at the cost of higher energy consumption. For depth perception at close range, stereopsis is the most precise but is available only to a few vertebrates. In contrast, motion parallax is used by many species including vertebrates as well as invertebrates. In a few cases accommodation is used for depth measurements or chromatic aberration. In motion vision the temporal resolution of the eye is most important. The ficker fusion frequency correlates in vertebrates with metabolic turnover and body temperature but also has very high values in insects. Apart from that the flicker fusion frequency generally declines with increasing body weight. Compared to animals the performance of the visual system in humans is among the best regarding light sensitivity, is the best regarding depth resolution and in the middle range regarding motion resolution.

The processing of linear perspective and binocular information for action and perception.

PubMed

Bruggeman, Hugo; Yonas, Albert; Konczak, Jürgen

2007-04-08

To investigate the processing of linear perspective and binocular information for action and for the perceptual judgment of depth, we presented viewers with an actual Ames trapezoidal window. The display, when presented perpendicular to the line of sight, provided perspective information for a rectangular window slanted in depth, while binocular information specified a planar surface in the fronto-parallel plane. We compared pointing towards the display-edges with perceptual judgment of their positions in depth as the display orientation was varied under monocular and binocular view. On monocular trials, pointing and depth judgment were based on the perspective information and failed to respond accurately to changes in display orientation because pictorial information did not vary sufficiently to specify the small differences in orientation. For binocular trials, pointing was based on binocular information and precisely matched the changes in display orientation whereas depth judgment was short of such adjustment and based upon both binocular and perspective-specified slant information. The finding, that on binocular trials pointing was considerably less responsive to the illusion than perceptual judgment, supports an account of two separate processing streams in the human visual system, a ventral pathway involved in object recognition and a dorsal pathway that produces visual information for the control of actions. Previously, similar differences between perception and action were explained by an alternate explanation, that is, viewers selectively attend to different parts of a display in the two tasks. The finding that under monocular view participants responded to perspective information in both the action and the perception task rules out the attention-based argument.

Neural correlates of monocular and binocular depth cues based on natural images: a LORETA analysis.

PubMed

Fischmeister, Florian Ph S; Bauer, Herbert

2006-10-01

Functional imaging studies investigating perception of depth rely solely on one type of depth cue based on non-natural stimulus material. To overcome these limitations and to provide a more realistic and complete set of depth cues natural stereoscopic images were used in this study. Using slow cortical potentials and source localization we aimed to identify the neural correlates of monocular and binocular depth cues. This study confirms and extends functional imaging studies, showing that natural images provide a good, reliable, and more realistic alternative to artificial stimuli, and demonstrates the possibility to separate the processing of different depth cues.

Virtual reality hardware and graphic display options for brain-machine interfaces

PubMed Central

Marathe, Amar R.; Carey, Holle L.; Taylor, Dawn M.

2009-01-01

Virtual reality hardware and graphic displays are reviewed here as a development environment for brain-machine interfaces (BMIs). Two desktop stereoscopic monitors and one 2D monitor were compared in a visual depth discrimination task and in a 3D target-matching task where able-bodied individuals used actual hand movements to match a virtual hand to different target hands. Three graphic representations of the hand were compared: a plain sphere, a sphere attached to the fingertip of a realistic hand and arm, and a stylized pacman-like hand. Several subjects had great difficulty using either stereo monitor for depth perception when perspective size cues were removed. A mismatch in stereo and size cues generated inappropriate depth illusions. This phenomenon has implications for choosing target and virtual hand sizes in BMI experiments. Target matching accuracy was about as good with the 2D monitor as with either 3D monitor. However, users achieved this accuracy by exploring the boundaries of the hand in the target with carefully controlled movements. This method of determining relative depth may not be possible in BMI experiments if movement control is more limited. Intuitive depth cues, such as including a virtual arm, can significantly improve depth perception accuracy with or without stereo viewing. PMID:18006069

The perception of ego-motion change in environments with varying depth: Interaction of stereo and optic flow.

PubMed

Ott, Florian; Pohl, Ladina; Halfmann, Marc; Hardiess, Gregor; Mallot, Hanspeter A

2016-07-01

When estimating ego-motion in environments (e.g., tunnels, streets) with varying depth, human subjects confuse ego-acceleration with environment narrowing and ego-deceleration with environment widening. Festl, Recktenwald, Yuan, and Mallot (2012) demonstrated that in nonstereoscopic viewing conditions, this happens despite the fact that retinal measurements of acceleration rate-a variable related to tau-dot-should allow veridical perception. Here we address the question of whether additional depth cues (specifically binocular stereo, object occlusion, or constant average object size) help break the confusion between narrowing and acceleration. Using a forced-choice paradigm, the confusion is shown to persist even if unambiguous stereo information is provided. The confusion can also be demonstrated in an adjustment task in which subjects were asked to keep a constant speed in a tunnel with varying diameter: Subjects increased speed in widening sections and decreased speed in narrowing sections even though stereoscopic depth information was provided. If object-based depth information (stereo, occlusion, constant average object size) is added, the confusion between narrowing and acceleration still remains but may be slightly reduced. All experiments are consistent with a simple matched filter algorithm for ego-motion detection, neglecting both parallactic and stereoscopic depth information, but leave open the possibility of cue combination at a later stage.

Voices of Dissent: Unpacking Vietnamese International Student Experience

ERIC Educational Resources Information Center

Huong, Le; Koo, Fung Kuen; Arambewela, Rodney; Zutshi, Ambika

2017-01-01

Purpose: The purpose of this paper is to examine Vietnamese international students' experiences with the campus learning environment by analysing differences in staff and student perceptions. Design/Methodology/Approach: Two focus groups (n = 12) and ten in-depth interviews were conducted with Vietnamese students and four in-depth interviews with…

Problems in depth perception : a method of simulating objects moving in depth.

DOT National Transportation Integrated Search

1965-12-01

Equations were developed for the simulation on a screen of the movement of an object or surface toward or away from an observer by the movement of a positive photographic transparency of the object or surface away or toward a point source. The genera...

Color appearance in stereoscopy

NASA Astrophysics Data System (ADS)

Gadia, Davide; Rizzi, Alessandro; Bonanomi, Cristian; Marini, Daniele; Galmonte, Alessandra; Agostini, Tiziano

2011-03-01

The relationship between color and lightness appearance and the perception of depth has been studied since a while in the field of perceptual psychology and psycho-physiology. It has been found that depth perception affects the final object color and lightness appearance. In the stereoscopy research field, many studies have been proposed on human physiological effects, considering e.g. geometry, motion sickness, etc., but few has been done considering lightness and color information. Goal of this paper is to realize some preliminar experiments in Virtual Reality in order to determine the effects of depth perception on object color and lightness appearance. We have created a virtual test scene with a simple 3D simultaneous contrast configuration. We have created three different versions of this scene, each with different choices of relative positions and apparent size of the objects. We have collected the perceptual responses of several users after the observation of the test scene in the Virtual Theater of the University of Milan, a VR immersive installation characterized by a semi-cylindrical screen that covers 120° of horizontal field of view from an observation distance of 3.5 m. We present a description of the experiments setup and procedure, and we discuss the obtained results.

Morphological Computation of Haptic Perception of a Controllable Stiffness Probe.

PubMed

Sornkarn, Nantachai; Dasgupta, Prokar; Nanayakkara, Thrishantha

2016-01-01

When people are asked to palpate a novel soft object to discern its physical properties such as texture, elasticity, and even non-homogeneity, they not only regulate probing behaviors, but also the co-contraction level of antagonistic muscles to control the mechanical impedance of fingers. It is suspected that such behavior tries to enhance haptic perception by regulating the function of mechanoreceptors at different depths of the fingertips and proprioceptive sensors such as tendon and spindle sensors located in muscles. In this paper, we designed and fabricated a novel two-degree of freedom variable stiffness indentation probe to investigate whether the regulation of internal stiffness, indentation, and probe sweeping velocity (PSV) variables affect the accuracy of the depth estimation of stiff inclusions in an artificial silicon phantom using information gain metrics. Our experimental results provide new insights into not only the biological phenomena of haptic perception but also new opportunities to design and control soft robotic probes.

Distance and Size Perception in Astronauts during Long-Duration Spaceflight

PubMed Central

Clément, Gilles; Skinner, Anna; Lathan, Corinna

2013-01-01

Exposure to microgravity during spaceflight is known to elicit orientation illusions, errors in sensory localization, postural imbalance, changes in vestibulo-spinal and vestibulo-ocular reflexes, and space motion sickness. The objective of this experiment was to investigate whether an alteration in cognitive visual-spatial processing, such as the perception of distance and size of objects, is also taking place during prolonged exposure to microgravity. Our results show that astronauts on board the International Space Station exhibit biases in the perception of their environment. Objects’ heights and depths were perceived as taller and shallower, respectively, and distances were generally underestimated in orbit compared to Earth. These changes may occur because the perspective cues for depth are less salient in microgravity or the eye-height scaling of size is different when an observer is not standing on the ground. This finding has operational implications for human space exploration missions. PMID:25369884

Parietal and frontal object areas underlie perception of object orientation in depth.

PubMed

Niimi, Ryosuke; Saneyoshi, Ayako; Abe, Reiko; Kaminaga, Tatsuro; Yokosawa, Kazuhiko

2011-05-27

Recent studies have shown that the human parietal and frontal cortices are involved in object image perception. We hypothesized that the parietal/frontal object areas play a role in differentiating the orientations (i.e., views) of an object. By using functional magnetic resonance imaging, we compared brain activations while human observers differentiated between two object images in depth-orientation (orientation task) and activations while they differentiated the images in object identity (identity task). The left intraparietal area, right angular gyrus, and right inferior frontal areas were activated more for the orientation task than for the identity task. The occipitotemporal object areas, however, were activated equally for the two tasks. No region showed greater activation for the identity task. These results suggested that the parietal/frontal object areas encode view-dependent visual features and underlie object orientation perception. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Canadian Early Childhood Educators' Perceptions of Young Children's Gender-Role Play and Cultural Identity

ERIC Educational Resources Information Center

Servos, Jennifer E.; Dewar, Brandy A.; Bosacki, Sandra L.; Coplan, Robert J.

2016-01-01

This article investigates early childhood educators' perceptions of children's gender-role play and the impact their cultural background plays in their gender identity and play behaviors. Through qualitative in-depth interviews, early childhood educators in Canada (n = 40) were asked questions relating to their experiences with children from…

Outsourcing Academic Development in Higher Education: Staff Perceptions of an International Program

ERIC Educational Resources Information Center

Dickson, Kerry; Hughes, Kate; Stephens, Bruce

2017-01-01

Increasingly, higher education support services are being outsourced. Our case study was of a program from a global, USA-based, non-profit organisation. From in-depth interviews, we investigated staff perceptions of academic development workshops and the efficacy of outsourcing to a transnational tertiary-support program. We found that…

Meanings and Experiences of Menstruation: Perceptions of Institutionalized Women with an Intellectual Disability

ERIC Educational Resources Information Center

Chou, Yueh-Ching; Lu, Zxy-Yann Jane; Wang, Frank T. Y.; Lan, Chang-Fu; Lin, Li-Chan

2008-01-01

Background: No studies have ever been conducted concerning menstrual experiences among women with an intellectual disability in Taiwan. Materials and Methods: An in-depth interview was conducted at three public institutions and perceptions and experiences regarding menstruation were elicited from 55 women aged 21-65 years. Results: The…

Do We Speak the Same Language? A Study of Faculty Perceptions of Information Literacy

ERIC Educational Resources Information Center

Cope, Jonathan; Sanabria, Jesús E.

2014-01-01

The authors analyze twenty in-depth interviews with faculty members about how they perceive information literacy (IL) to examine two key factors: how disciplinary background influences conceptions of IL among faculty members in academic departments and how the instructors' perception of information literacy differs from that of professionals in…

Students' Experiences of Learning: Orientations to Learning, Perceptions of Gains, and Development as Learners.

ERIC Educational Resources Information Center

Morgan, Alistair; And Others

Students' orientations to learning, their perceptions of gain from their studies at Great Britain's Open University, and their development as learners were studied. Thirty students were followed from their first university course, the Social Science Foundation Course, through their two subsequent years of study, using in-depth interviews to…

Perceptions of Child Sexual Abuse--A Qualitative Interview Study with Representatives of the Socio-Legal System in Urban Tanzania

ERIC Educational Resources Information Center

Kisanga, Felix; Mbwambo, Jessie; Hogan, Norah; Nystrom, Lennarth; Emmelin, Maria; Lindmark, Gunilla

2010-01-01

Through in-depth interviews, this study explored perceptions and experiences of key players handling child sexual offense cases in Dar es Salaam, Tanzania. The informants included public police investigators, magistrates, legal workers, and social workers working with nongovernmental organizations. The interviews were recorded, transcribed…

Bullying and Victimisation Dynamics in High School: An Exploratory Case Study

ERIC Educational Resources Information Center

Lekunze, Lucy M. George; Strom, B. Ivan

2017-01-01

Bullying is a worldwide concern and erroneous perceptions of the phenomenon could underscore unsustainable interventions. The purpose of this qualitative exploratory case study was to examine, in-depth, how some high school teachers from two schools in New Jersey perceived student bullying. The primary research question was: What perceptions do…

Adolescent Girls' Perceptions of Physical Activity: A Focus Group Study

ERIC Educational Resources Information Center

Whitehead, Sarah; Biddle, Stuart

2008-01-01

Low levels of physical activity among adolescent girls are a cause for concern. Examining girls' physical activity perceptions and motivations through in-depth qualitative research allows for greater understanding of the reasons behind their physical activity-related choices. Forty-seven girls aged 14 to 16 years participated in exploratory focus…

Investigating Principals' Knowledge and Perceptions of Second Language Programs for English Language Learners

ERIC Educational Resources Information Center

Padron, Yolanda N.; Waxman, Hersh C.

2016-01-01

This study examined principals' knowledge and perceptions of second language programs for English language learners (ELLs) operating in their schools. An open-ended survey and in-depth interviews were used to examine elementary school principals' knowledge of the second language programs implemented at their schools. The survey asked principals…

Poor shape perception is the reason reaches-to-grasp are visually guided online.

PubMed

Lee, Young-Lim; Crabtree, Charles E; Norman, J Farley; Bingham, Geoffrey P

2008-08-01

Both judgment studies and studies of feedforward reaching have shown that the visual perception of object distance, size, and shape are inaccurate. However, feedback has been shown to calibrate feedfoward reaches-to-grasp to make them accurate with respect to object distance and size. We now investigate whether shape perception (in particular, the aspect ratio of object depth to width) can be calibrated in the context of reaches-to-grasp. We used cylindrical objects with elliptical cross-sections of varying eccentricity. Our participants reached to grasp the width or the depth of these objects with the index finger and thumb. The maximum grasp aperture and the terminal grasp aperture were used to evaluate perception. Both occur before the hand has contacted an object. In Experiments 1 and 2, we investigated whether perceived shape is recalibrated by distorted haptic feedback. Although somewhat equivocal, the results suggest that it is not. In Experiment 3, we tested the accuracy of feedforward grasping with respect to shape with haptic feedback to allow calibration. Grasping was inaccurate in ways comparable to findings in shape perception judgment studies. In Experiment 4, we hypothesized that online guidance is needed for accurate grasping. Participants reached to grasp either with or without vision of the hand. The result was that the former was accurate, whereas the latter was not. We conclude that shape perception is not calibrated by feedback from reaches-to-grasp and that online visual guidance is required for accurate grasping because shape perception is poor.

D3D augmented reality imaging system: proof of concept in mammography.

PubMed

Douglas, David B; Petricoin, Emanuel F; Liotta, Lance; Wilson, Eugene

2016-01-01

The purpose of this article is to present images from simulated breast microcalcifications and assess the pattern of the microcalcifications with a technical development called "depth 3-dimensional (D3D) augmented reality". A computer, head display unit, joystick, D3D augmented reality software, and an in-house script of simulated data of breast microcalcifications in a ductal distribution were used. No patient data was used and no statistical analysis was performed. The D3D augmented reality system demonstrated stereoscopic depth perception by presenting a unique image to each eye, focal point convergence, head position tracking, 3D cursor, and joystick fly-through. The D3D augmented reality imaging system offers image viewing with depth perception and focal point convergence. The D3D augmented reality system should be tested to determine its utility in clinical practice.

Illusory Distance Modulates Perceived Size of Afterimage despite the Disappearance of Depth Cues

PubMed Central

Liu, Shengxi; Lei, Quan

2016-01-01

It is known that the perceived size of an afterimage is modulated by the perceived distance between the observer and the depth plane on which the afterimage is projected (Emmert’s law). Illusions like Ponzo demonstrate that illusory distance induced by depth cues can also affect the perceived size of an object. In this study, we report that the illusory distance not only modulates the perceived size of object’s afterimage during the presence of the depth cues, but the modulation persists after the disappearance of the depth cues. We used an adapted version of the classic Ponzo illusion. Illusory depth perception was induced by linear perspective cues with two tilted lines converging at the upper boundary of the display. Two horizontal bars were placed between the two lines, resulting in a percept of the upper bar to be farther away than the lower bar. Observers were instructed to make judgment about the relative size of the afterimage of the lower and the upper bars after adaptation. When the perspective cues and the bars were static, the illusory effect of the Ponzo afterimage is consistent with that of the traditional size-distance illusion. When the perspective cues were flickering and the bars were static, only the afterimage of the latter was perceived, yet still a considerable amount of the illusory effect was perceived. The results could not be explained by memory of a prejudgment of the bar length during the adaptation phase. The findings suggest that cooccurrences of depth cues and object may link a depth marker for the object, so that the perceived size of the object or its afterimage is modulated by feedback of depth information from higher-level visual cortex even when there is no depth cues directly available on the retinal level. PMID:27391335

Assessing a VR-based learning environment for anatomy education.

PubMed

Hoffman, H; Murray, M; Hettinger, L; Viirre, E

1998-01-01

The purpose of the research proposed herein is to develop an empirical, methodological tool for the assessment of visual depth perception in virtual environments (VEs). Our goal is to develop and employ a behaviorally-based method for assessing the impact of VE design features on the perception of visual depth as indexed by the performance of fundamental perceptual-motor activities. Specifically, in this experiment we will assess the affect of two dimensions of VE system design--(1) viewing condition or "level of immersion", and (2) layout/design of the VE--on the performance of an engaging, game-like task. The characteristics of the task to be employed are as follows--(1) it places no demands on cognition in the form of problem solving, retrieval of previously learned information, or other analytic activity in order to assure that (2) variations in task performance can be exclusively attributed to the extent to which the experimental factors influence visual depth perception. Subjects' performance will be assessed in terms of the speed and accuracy of task performance, as well as underlying dimensions of performance such as workload, fatigue, and physiological well being (i.e., cybersickness). The results of this experiment will provide important information on the effect of VE immersion and other VE design issues on human perception and performance. Further development, refinement, and validation of this behaviorally-based methodology will be pursued to provide user-centered design criteria for the design and use of VE systems.

Edge-Region Grouping in Figure-Ground Organization and Depth Perception

ERIC Educational Resources Information Center

Palmer, Stephen E.; Brooks, Joseph L.

2008-01-01

Edge-region grouping (ERG) is proposed as a unifying and previously unrecognized class of relational information that influences figure-ground organization and perceived depth across an edge. ERG occurs when the edge between two regions is differentially grouped with one region based on classic principles of similarity grouping. The ERG hypothesis…

Health perceptions of Mexican American women.

PubMed

Mendelson, Cindy

2002-07-01

This article describes the health perceptions of a sample of moderately to highly acculturated Mexican American women. Using an ethnographic design, the author interviewed 13 women to determine their health perceptions. The interviews were guided by the domains of health described in the World Health Organization (WHO) definition of health. Three broad categories of health perceptions were identified: the physical body, the emotional component, and finding balance. With the addition of a spiritual component, the WHO definition was a useful tool for uncovering health perceptions. The process of in-depth ethnographic interviewing provided a contextual view of health in which the complexity of intrafamilial relationships was revealed, as were the importance of spirituality as a coping mechanism and the perception of health as an integrated, holistic experience.

Dissociation between visual perception of allocentric distance and visually directed walking of its extent.

PubMed

Kudoh, Nobuo

2005-01-01

Walking without vision to previously viewed targets was compared with visual perception of allocentric distance in two experiments. Experimental evidence had shown that physically equal distances in a sagittal plane on the ground were perceptually underestimated as compared with those in a frontoparallel plane, even under full-cue conditions. In spite of this perceptual anisotropy of space, Loomis et al (1992 Journal of Experimental Psychology. Human Perception and Performance 18 906-921) found that subjects could match both types of distances in a blind-walking task. In experiment 1 of the present study, subjects were required to reproduce the extent of allocentric distance between two targets by either walking towards the targets, or by walking in a direction incompatible with the locations of the targets. The latter condition required subjects to derive an accurate allocentric distance from information based on the perceived locations of the two targets. The walked distance in the two conditions was almost identical whether the two targets were presented in depth (depth-presentation condition) or in the frontoparallel plane (width-presentation condition). The results of a perceptual-matching task showed that the depth distances had to be much greater than the width distances in order to be judged to be equal in length (depth compression). In experiment 2, subjects were required to reproduce the extent of allocentric distance from the viewing point by blindly walking in a direction other than toward the targets. The walked distance in the depth-presentation condition was shorter than that in the width-presentation condition. This anisotropy in motor responses, however, was mainly caused by apparent overestimation of length oriented in width, not by depth compression. In addition, the walked distances were much better scaled than those in experiment 1. These results suggest that the perceptual and motor systems share a common representation of the location of targets, whereas a dissociation in allocentric distance exists between the two systems in full-cue conditions.

Real-time multiple human perception with color-depth cameras on a mobile robot.

PubMed

Zhang, Hao; Reardon, Christopher; Parker, Lynne E

2013-10-01

The ability to perceive humans is an essential requirement for safe and efficient human-robot interaction. In real-world applications, the need for a robot to interact in real time with multiple humans in a dynamic, 3-D environment presents a significant challenge. The recent availability of commercial color-depth cameras allow for the creation of a system that makes use of the depth dimension, thus enabling a robot to observe its environment and perceive in the 3-D space. Here we present a system for 3-D multiple human perception in real time from a moving robot equipped with a color-depth camera and a consumer-grade computer. Our approach reduces computation time to achieve real-time performance through a unique combination of new ideas and established techniques. We remove the ground and ceiling planes from the 3-D point cloud input to separate candidate point clusters. We introduce the novel information concept, depth of interest, which we use to identify candidates for detection, and that avoids the computationally expensive scanning-window methods of other approaches. We utilize a cascade of detectors to distinguish humans from objects, in which we make intelligent reuse of intermediary features in successive detectors to improve computation. Because of the high computational cost of some methods, we represent our candidate tracking algorithm with a decision directed acyclic graph, which allows us to use the most computationally intense techniques only where necessary. We detail the successful implementation of our novel approach on a mobile robot and examine its performance in scenarios with real-world challenges, including occlusion, robot motion, nonupright humans, humans leaving and reentering the field of view (i.e., the reidentification challenge), human-object and human-human interaction. We conclude with the observation that the incorporation of the depth information, together with the use of modern techniques in new ways, we are able to create an accurate system for real-time 3-D perception of humans by a mobile robot.

The representation of visual depth perception based on the plenoptic function in the retina and its neural computation in visual cortex V1.

PubMed

Songnian, Zhao; Qi, Zou; Chang, Liu; Xuemin, Liu; Shousi, Sun; Jun, Qiu

2014-04-23

How it is possible to "faithfully" represent a three-dimensional stereoscopic scene using Cartesian coordinates on a plane, and how three-dimensional perceptions differ between an actual scene and an image of the same scene are questions that have not yet been explored in depth. They seem like commonplace phenomena, but in fact, they are important and difficult issues for visual information processing, neural computation, physics, psychology, cognitive psychology, and neuroscience. The results of this study show that the use of plenoptic (or all-optical) functions and their dual plane parameterizations can not only explain the nature of information processing from the retina to the primary visual cortex and, in particular, the characteristics of the visual pathway's optical system and its affine transformation, but they can also clarify the reason why the vanishing point and line exist in a visual image. In addition, they can better explain the reasons why a three-dimensional Cartesian coordinate system can be introduced into the two-dimensional plane to express a real three-dimensional scene. 1. We introduce two different mathematical expressions of the plenoptic functions, Pw and Pv that can describe the objective world. We also analyze the differences between these two functions when describing visual depth perception, that is, the difference between how these two functions obtain the depth information of an external scene.2. The main results include a basic method for introducing a three-dimensional Cartesian coordinate system into a two-dimensional plane to express the depth of a scene, its constraints, and algorithmic implementation. In particular, we include a method to separate the plenoptic function and proceed with the corresponding transformation in the retina and visual cortex.3. We propose that size constancy, the vanishing point, and vanishing line form the basis of visual perception of the outside world, and that the introduction of a three-dimensional Cartesian coordinate system into a two dimensional plane reveals a corresponding mapping between a retinal image and the vanishing point and line.

The representation of visual depth perception based on the plenoptic function in the retina and its neural computation in visual cortex V1

PubMed Central

2014-01-01

Background How it is possible to “faithfully” represent a three-dimensional stereoscopic scene using Cartesian coordinates on a plane, and how three-dimensional perceptions differ between an actual scene and an image of the same scene are questions that have not yet been explored in depth. They seem like commonplace phenomena, but in fact, they are important and difficult issues for visual information processing, neural computation, physics, psychology, cognitive psychology, and neuroscience. Results The results of this study show that the use of plenoptic (or all-optical) functions and their dual plane parameterizations can not only explain the nature of information processing from the retina to the primary visual cortex and, in particular, the characteristics of the visual pathway’s optical system and its affine transformation, but they can also clarify the reason why the vanishing point and line exist in a visual image. In addition, they can better explain the reasons why a three-dimensional Cartesian coordinate system can be introduced into the two-dimensional plane to express a real three-dimensional scene. Conclusions 1. We introduce two different mathematical expressions of the plenoptic functions, P w and P v that can describe the objective world. We also analyze the differences between these two functions when describing visual depth perception, that is, the difference between how these two functions obtain the depth information of an external scene. 2. The main results include a basic method for introducing a three-dimensional Cartesian coordinate system into a two-dimensional plane to express the depth of a scene, its constraints, and algorithmic implementation. In particular, we include a method to separate the plenoptic function and proceed with the corresponding transformation in the retina and visual cortex. 3. We propose that size constancy, the vanishing point, and vanishing line form the basis of visual perception of the outside world, and that the introduction of a three-dimensional Cartesian coordinate system into a two dimensional plane reveals a corresponding mapping between a retinal image and the vanishing point and line. PMID:24755246

Perceptions and Practices of Stimulating Children's Cognitive Development among Moroccan Immigrant Mothers

ERIC Educational Resources Information Center

el Moussaoui, Nabila; Braster, Sjaak

2011-01-01

We explored the perceptions of children's cognitive development among Moroccan Arabic and Berber immigrant mothers who cannot read, who are less educated, middle educated or highly educated in the Netherlands. A series of in-depth interviews was conducted with 22 mothers with young children (mean age = 5 years and 6 months). Qualitative data…

Advanced ESL Students' Prior EFL Education and Their Perceptions of Oral Corrective Feedback

ERIC Educational Resources Information Center

Lee, Eun Jeong

2016-01-01

The author in this study examines how advanced-level adult English as a Second Language (ESL) students' previous English as a Foreign Language (EFL) classroom experiences influence their perceptions of their teachers' oral corrective feedback (CF). It uses in-depth qualitative data to characterize the participants' prior English learning, and to…

On the Anisotropy of Perceived Ground Extents and the Interpretation of Walked Distance as a Measure of Perception

ERIC Educational Resources Information Center

Li, Zhi; Sun, Emily; Strawser, Cassandra J.; Spiegel, Ariana; Klein, Brennan; Durgin, Frank H.

2013-01-01

Two experiments are reported concerning the perception of ground extent to discover whether prior reports of anisotropy between frontal extents and extents in depth were consistent across different measures (visual matching and pantomime walking) and test environments (outdoor environments and virtual environments). In Experiment 1 it was found…

"Parenting about Peace": Exploring Taiwanese Parents' and Children's Perceptions in a Shared Political and Sociocultural Context

ERIC Educational Resources Information Center

Deng, Liang-Yu F.

2012-01-01

This study explored what Taiwanese parents would educate their children about peace and what children retained from parental teaching, as well as children's reported communication with parents about peace. In-depth interviews were conducted with 60 parents and one of their children. Based on the perceptions of children, the most influential…

Perspectives on HIV/AIDS Stigma and Discrimination: Voices of Some Young People in Ghana

ERIC Educational Resources Information Center

Oduro, Georgina Yaa; Otsin, Mercy

2013-01-01

This paper examines Ghanaian young people's perceptions of the determinants of HIV- and AIDS-related stigma and discrimination, and how these perceptions may influence the de-stigmatisation process. Drawing on findings from an in-depth, multi-method qualitative study involving 104 school and street young people aged between 14 and 19 years, the…

Teaching Reading Comprehension to Students with Autism Spectrum Disorders in Social Studies Classrooms: Middle School Teacher Perceptions

ERIC Educational Resources Information Center

Burke, Lisa; Hsieh, Wu-Ying; Lopez-Reyna, Norma; Servilio, Kathryn

2016-01-01

The purpose of this qualitative study was to describe the perceptions of general education middle school social studies teachers related to their teaching practices and the inclusion of students with Autism Spectrum Disorder (ASD) in their classrooms. More specifically, an in-depth exploration of general education social studies teachers'…

Rethinking the Scope of Environmental Injustice: Perceptions of Health Hazards in a Rural Native American Community Exposed to Carbon Black

ERIC Educational Resources Information Center

Shriver, Thomas E.; Webb, Gary R.

2009-01-01

We use in-depth interviews, participant observation, and document analysis to examine perceptions of environmental health and justice among Native Americans in a rural Oklahoma community. Residents live near the Continental Carbon Company, which manufactures a rubber compound know as "carbon black." Ponca tribal members believe their…

The Seeds of Discontent: Examining Youth Perceptions of Higher Education in Syria

ERIC Educational Resources Information Center

Buckner, Elizabeth

2013-01-01

This article examines young Syrians' perceptions of higher education after the 2001 reforms, which expanded access to higher education and permitted the establishment of private universities. Data come from in-depth interviews conducted with 22 Syrians residing in Damascus, aged 18-32 in 2009. Analysis indicates youth are critical of the higher…

Female Survivors' Perceptions of Lifelong Impact on Their Education of Child Abuse Suffered in Orphanages

ERIC Educational Resources Information Center

Goldman, Juliette D. G.; Bode, Andrew

2012-01-01

Many children raised in orphanages suffered ongoing child abuse and neglect including sexual abuse, and nearly all were denied an adequate education. This paper explores adult females' perceptions of the impacts on their education of child sexual abuse they suffered while living in orphanages in Australia. In-depth qualitative and anonymous…

Buried by Autism: Older Parents' Perceptions of Autism

ERIC Educational Resources Information Center

Hines, Monique; Balandin, Susan; Togher, Leanne

2012-01-01

In this study, we explored older parents' perceptions of their adult sons and daughters with autism in order to gain insights into how parents' beliefs about autism may influence their coping. Narrative analysis of in-depth interviews held with 16 parents aged 60 years and older of adults with autism revealed that these parents perceived that…

Students' Use of Personal Technologies in the University Classroom: Analysing the Perceptions of the Digital Generation

ERIC Educational Resources Information Center

Langan, Debra; Schott, Nicole; Wykes, Timothy; Szeto, Justin; Kolpin, Samantha; Lopez, Carla; Smith, Nathan

2016-01-01

Faculty frequently express concerns about students' personal use of information and communication technologies in today's university classrooms. As a requirement of a graduate research methodology course in a university in Ontario, Canada, the authors conducted qualitative research to gain an in-depth understanding of students' perceptions of this…

Learning from Tutorials: A Qualitative Study of Approaches to Learning and Perceptions of Tutorial Interaction

ERIC Educational Resources Information Center

Herrmann, Kim Jesper

2014-01-01

This study examines differences in university students' approaches to learning when attending tutorials as well as variation in students' perceptions of tutorials as an educational arena. In-depth qualitative analysis of semi-structured interviews with undergraduates showed how surface and deep approaches to learning were revealed in the…

Frequent Fliers, School Phobias, and the Sick Student: School Health Personnel's Perceptions of Students Who Refuse School

ERIC Educational Resources Information Center

Torrens Armstrong, Anna M.; McCormack Brown, Kelli R.; Brindley, Roger; Coreil, Jeannine; McDermott, Robert J.

2011-01-01

Background: This study explored school personnel's perceptions of school refusal, as it has been described as a "common educational and public health problem" that is less tolerated due to increasing awareness of the potential socioeconomic consequences of this phenomenon. Methods: In-depth interviews were conducted with school personnel…

Teachers' Perceptions, Attitudes and Feelings towards Pupils of Roma Origin

ERIC Educational Resources Information Center

Zachos, Dimitris T.

2017-01-01

In this paper, the focus is on schools' responses to multiculturalism. We present a research project that was designed to explore feelings, perceptions and attitudes of teachers towards pupils of Roma origin in two different Greek schools. Our research strategy involved case studies and in-depth semi-structured interview was our main research…

Perception of Spiritual Health: A Qualitative Content Analysis in Iranian Older Adults

ERIC Educational Resources Information Center

Zibad, Hosein Ajam; Foroughan, Mahshid; Shahboulaghi, Farahnaz Mohammadi; Rafiey, Hassan; Rassouli, Maryam

2017-01-01

The present study was performed with the aim to explain older people's perceptions of spiritual health. It was conducted using the conventional content analysis method. Twelve individuals aged 60 years or older with normal cognition participated in the study using purposive sampling. Data were collected by in-depth interviews. Data analysis…

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

ERIC Educational Resources Information Center

Brydges, Colton; Mkandawire, Paul

2017-01-01

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

The moon illusion: a test of the vestibular hypothesis under monocular viewing conditions.

PubMed

Carter, D S

1977-12-01

The results of earlier monocular experiments on the moon illusion have been either negative or confounded. To test the role of vestibular function, 24 subjects made forced-choice distance comparisons between stimuli mounted in translucent tubes. The stimulus tube for standard distance could be positioned in three viewing angles (45 degrees up, horizontal, and 45 degrees down). A comparison tube adjustable for distance was mounted horizontally. There was a greater perception of depth in the downward looking condition. The relatively weak effects are discussed in terms of a two-hypothesis explanation of the real-life moon illusion and the poor cues for depth perception in monocular viewing.

Stereomotion speed perception is contrast dependent

NASA Technical Reports Server (NTRS)

Brooks, K.

2001-01-01

The effect of contrast on the perception of stimulus speed for stereomotion and monocular lateral motion was investigated for successive matches in random-dot stimuli. The familiar 'Thompson effect'--that a reduction in contrast leads to a reduction in perceived speed--was found in similar proportions for both binocular images moving in depth, and for monocular images translating laterally. This result is consistent with the idea that the monocular motion system has a significant input to the stereomotion system, and dominates the speed percept for approaching motion.

Retinal fundus imaging with a plenoptic sensor

NASA Astrophysics Data System (ADS)

Thurin, Brice; Bloch, Edward; Nousias, Sotiris; Ourselin, Sebastien; Keane, Pearse; Bergeles, Christos

2018-02-01

Vitreoretinal surgery is moving towards 3D visualization of the surgical field. This require acquisition system capable of recording such 3D information. We propose a proof of concept imaging system based on a light-field camera where an array of micro-lenses is placed in front of a conventional sensor. With a single snapshot, a stack of images focused at different depth are produced on the fly, which provides enhanced depth perception for the surgeon. Difficulty in depth localization of features and frequent focus-change during surgery are making current vitreoretinal heads-up surgical imaging systems cumbersome to use. To improve the depth perception and eliminate the need to manually refocus on the instruments during the surgery, we designed and implemented a proof-of-concept ophthalmoscope equipped with a commercial light-field camera. The sensor of our camera is composed of an array of micro-lenses which are projecting an array of overlapped micro-images. We show that with a single light-field snapshot we can digitally refocus between the retina and a tool located in front of the retina or display an extended depth-of-field image where everything is in focus. The design and system performances of the plenoptic fundus camera are detailed. We will conclude by showing in vivo data recorded with our device.

Indoor vs. Outdoor Depth Perception for Mobile Augmented Reality

DTIC Science & Technology

2009-03-01

International Symposium on Mixed and Augmented Reality, pages 77–86, Sept. 2008. [12] M. A. Livingston, J. E. Swan II, J. L. Gabbard , T. H. Höllerer, D. Hix...D. Brown, Y. Baillot, J. L. Gabbard , and D. Hix. A perceptual matching technique for depth judgments in optical, see-through augmented reality. In

A Small-Scale Study on Student Teachers' Perceptions of Classroom Management and Methods for Dealing with Misbehaviour

ERIC Educational Resources Information Center

Atici, Meral

2007-01-01

The purpose of this study is to identify student teachers' perceptions of classroom management and methods for dealing with misbehaviour. In-depth interviews with nine student teachers at Cukurova University (CU) in Turkey have been conducted twice, prior to and at the end of their teaching practice. Instructional management, behaviour management,…

Focus Groups to Explore the Perceptions of Older Adults on a Pedometer-Based Intervention

ERIC Educational Resources Information Center

Jones, David B.; Richeson, Nancy E.; Croteau, Karen A.; Farmer, Bonnie Cashin

2009-01-01

Focus group methodology was used to explore in depth the perceptions of older adults who had participated in a 12-week pedometer-based intervention. Nineteen women and 8 men, ages 55-86 years, volunteered to take part in the focus groups following participation in the intervention. Four focus groups of six to eight participants were scheduled at…

Write On or Write Off? An Exploration of Asian International Students' Approaches to Essay Writing at an Australian University

ERIC Educational Resources Information Center

Green, Wendy

2007-01-01

This paper investigates the approaches taken to essay writing by five Asian international students at an Australian university. Analysis of their in-depth interviews reveals links between their perceptions of learning, their perceptions of essay writing, their motivation for completing the task, and their awareness of the structural conventions of…

"You Must Know Where You Come From": South African Youths' Perceptions of Religion in Time of Social Change

ERIC Educational Resources Information Center

Brittian, Aerika S.; Lewin, Nina; Norris, Shane A.

2013-01-01

This study examined South African youths' perceptions of religion during a period of social and economic transition. In-depth interviews were conducted with 55 Black South African youth (age 18) living in the Johannesburg-Soweto metropolitan area. Data were analyzed in a manner consistent with grounded theory methodology and structural coding.…

A Longitudinal Look at Attitudes and Perceptions Related to the Integration of Mathematics, Science, and Technology Education

ERIC Educational Resources Information Center

Berlin, Donna F.; White, Arthur L.

2012-01-01

The purpose of this study is to provide an in-depth analysis of attitudes and perceptions related to the integration of mathematics, science, and technology education of preservice teachers preparing to teach STEM disciplines. Longitudinal data by individual cohort and across 7 years of the Integrated Mathematics, Science, and Technology (MSAT)…

Understanding Behavior Disorders: Their Perception, Acceptance, and Treatment--A Cross-Cultural Comparison between India and the United States

ERIC Educational Resources Information Center

Chakraborti-Ghosh, Sumita

2008-01-01

The purpose of this study was to explore the perceptions, identification and treatment of students with behavior problems or disorders in India and the United States. Participants in the study were students and teachers in the United States and India. A qualitative approach included in-depth interviews and participant observations. These were…

''I Eat to Be Happy, to Be Strong, and to Live.'' Perceptions of Rural and Urban Adolescents in Cameroon, Africa

ERIC Educational Resources Information Center

Dapi, Leonie N.; Omoloko, Cecile; Janlert, Urban; Dahlgren, Lars; Haglin, Lena

2007-01-01

Objective: To investigate factors influencing rural and urban adolescents' food perceptions during a time of nutritional transition in Cameroon, Africa. Design: Qualitative in-depth interviews. Settings: Yaounde urban and Bandja rural areas. Participants: Fifteen adolescents 12 to 15 years old purposely selected from schools in urban and rural…

Perceptions of Engineering Students, Lecturers and Academic Development Practitioners about Academic Development Classes at a University of Technology

ERIC Educational Resources Information Center

Shange, Thembeka G. C.

2015-01-01

With the increase in student enrolments in higher education, which has resulted in changes to student profiles, academic development has become important in terms of students' success. This article is a report on a qualitative study that used in-depth interviews to investigate the perceptions of Engineering students and staff to academic…

Between Ritual and Spiritual: Teachers' Perceptions and Practices Regarding Prayer Education in TALI Day Schools in Israel

ERIC Educational Resources Information Center

Muszkat-Barkan, Michal

2015-01-01

The aim of this qualitative study is to describe teachers' perceptions and roles in prayer education in TALI day schools in Israel, using in-depth oral Interviews, written questionnaires and written materials of the schools' network. Two educational ideologies were identified: Belonging to the Jewish collective and Personal-spiritual ideology.…

Morphological Computation of Haptic Perception of a Controllable Stiffness Probe

PubMed Central

Sornkarn, Nantachai; Dasgupta, Prokar; Nanayakkara, Thrishantha

2016-01-01

When people are asked to palpate a novel soft object to discern its physical properties such as texture, elasticity, and even non-homogeneity, they not only regulate probing behaviors, but also the co-contraction level of antagonistic muscles to control the mechanical impedance of fingers. It is suspected that such behavior tries to enhance haptic perception by regulating the function of mechanoreceptors at different depths of the fingertips and proprioceptive sensors such as tendon and spindle sensors located in muscles. In this paper, we designed and fabricated a novel two-degree of freedom variable stiffness indentation probe to investigate whether the regulation of internal stiffness, indentation, and probe sweeping velocity (PSV) variables affect the accuracy of the depth estimation of stiff inclusions in an artificial silicon phantom using information gain metrics. Our experimental results provide new insights into not only the biological phenomena of haptic perception but also new opportunities to design and control soft robotic probes. PMID:27257814

Human Factors in Virtual Reality Development

NASA Technical Reports Server (NTRS)

Kaiser, Mary K.; Proffitt, Dennis R.; Null, Cynthia H. (Technical Monitor)

1995-01-01

This half-day tutorial will provide an overview of basic perceptual functioning as it relates to the design of virtual environment systems. The tutorial consists of three parts. First, basic issues in visual perception will be presented, including discussions of the visual sensations of brightness and color, and the visual perception of depth relationships in three-dimensional space (with a special emphasis on motion -specified depth). The second section will discuss the importance of conducting human-factors user studies and evaluations. Examples and suggestions on how best to get help with user studies will be provided. Finally, we will discuss how, by drawing on their complementary competencies, perceptual psychologists and computer engineers can work as a team to develop optimal VR systems, technologies, and techniques.

The role of stereopsis (three-dimensional vision) in dentistry: review of the current literature.

PubMed

Syrimi, M; Ali, N

2015-05-22

Clinical dental work is placing increasing demands on a clinician's vision as new techniques that require fine detail become more common. High hand-eye coordination requires good visual acuity as well as other psychological and neurological qualities such as stereopsis. Stereopsis (three-dimensional vision) is the highest form of depth perception obtained by visual disparity of images formed in the retinas of two eyes. It is believed to confer functional benefits on everyday tasks such as hand-eye coordination. Although its role in depth perception has long been established, little is known regarding the importance of stereopsis in dentistry. This article reviews the role of stereopsis in everyday life and the available literature on the importance of stereopsis in dentistry.

Multimedia article. The keys to the new laparoscopic world Thumbs up! knot and Tornado knot.

PubMed

Uchida, K; Haruta, N; Okajima, M; Matsuda, M; Yamamoto, M

2005-06-01

Most laparoscopic surgeons feel some anxiety when performing intracorporeal knotting with conventional techniques [1, 2]. Two factors contribute to this anxiety. The first is the necessity of recognizing three dimensions on a two-dimensional monitor. The conventional intracorporeal knotting techniques make loops by twisting the thread with a second pair of forceps. This necessitates cooperative movement of both hands, with the added difficulties of depth perception. Regular touch confirmations reduce problems with depth perception. However, touch confirmation is more complicated in laparoscopic surgery than in laparotomy. The second problem is that tied loops can come loose and escape the instruments, especially with hard thread. This is not only stressful but also increases operation time.

The venetian-blind effect: a preference for zero disparity or zero slant?

PubMed Central

Vlaskamp, Björn N. S.; Guan, Phillip; Banks, Martin S.

2013-01-01

When periodic stimuli such as vertical sinewave gratings are presented to the two eyes, the initial stage of disparity estimation yields multiple solutions at multiple depths. The solutions are all frontoparallel when the sinewaves have the same spatial frequency; they are all slanted when the sinewaves have quite different frequencies. Despite multiple solutions, humans perceive only one depth in each visual direction: a single frontoparallel plane when the frequencies are the same and a series of small slanted planes—Venetian blinds—when the frequencies are quite different. These percepts are consistent with a preference for solutions that minimize absolute disparity or overall slant. The preference for minimum disparity and minimum slant are identical for gaze at zero eccentricity; we dissociated the predictions of the two by measuring the occurrence of Venetian blinds when the stimuli were viewed in eccentric gaze. The results were generally quite consistent with a zero-disparity preference (Experiment 1), but we also observed a shift toward a zero-slant preference when the edges of the stimulus had zero slant (Experiment 2). These observations provide useful insights into how the visual system constructs depth percepts from a multitude of possible depths. PMID:24273523

The venetian-blind effect: a preference for zero disparity or zero slant?

PubMed

Vlaskamp, Björn N S; Guan, Phillip; Banks, Martin S

2013-01-01

When periodic stimuli such as vertical sinewave gratings are presented to the two eyes, the initial stage of disparity estimation yields multiple solutions at multiple depths. The solutions are all frontoparallel when the sinewaves have the same spatial frequency; they are all slanted when the sinewaves have quite different frequencies. Despite multiple solutions, humans perceive only one depth in each visual direction: a single frontoparallel plane when the frequencies are the same and a series of small slanted planes-Venetian blinds-when the frequencies are quite different. These percepts are consistent with a preference for solutions that minimize absolute disparity or overall slant. The preference for minimum disparity and minimum slant are identical for gaze at zero eccentricity; we dissociated the predictions of the two by measuring the occurrence of Venetian blinds when the stimuli were viewed in eccentric gaze. The results were generally quite consistent with a zero-disparity preference (Experiment 1), but we also observed a shift toward a zero-slant preference when the edges of the stimulus had zero slant (Experiment 2). These observations provide useful insights into how the visual system constructs depth percepts from a multitude of possible depths.

Stereoscopy in cinematographic synthetic imagery

NASA Astrophysics Data System (ADS)

Eisenmann, Jonathan; Parent, Rick

2009-02-01

In this paper we present experiments and results pertaining to the perception of depth in stereoscopic viewing of synthetic imagery. In computer animation, typical synthetic imagery is highly textured and uses stylized illumination of abstracted material models by abstracted light source models. While there have been numerous studies concerning stereoscopic capabilities, conventions for staging and cinematography in stereoscopic movies have not yet been well-established. Our long-term goal is to measure the effectiveness of various cinematography techniques on the human visual system in a theatrical viewing environment. We would like to identify the elements of stereoscopic cinema that are important in terms of enhancing the viewer's understanding of a scene as well as providing guidelines for the cinematographer relating to storytelling. In these experiments we isolated stereoscopic effects by eliminating as many other visual cues as is reasonable. In particular, we aim to empirically determine what types of movement in synthetic imagery affect the perceptual depth sensing capabilities of our viewers. Using synthetic imagery, we created several viewing scenarios in which the viewer is asked to locate a target object's depth in a simple environment. The scenarios were specifically designed to compare the effectiveness of stereo viewing, camera movement, and object motion in aiding depth perception. Data were collected showing the error between the choice of the user and the actual depth value, and patterns were identified that relate the test variables to the viewer's perceptual depth accuracy in our theatrical viewing environment.

The Impact of Sexuality in Contemporary Culture: An Interpretive Study of Perceptions and Choices in Private Sector Dance Education

ERIC Educational Resources Information Center

Risner, Doug; Godfrey, Heidi; Simmons, Linda C.

2004-01-01

The ways in which seven private sector dance professionals in the United States perceive the impact of sexuality in contemporary culture and the choices that they make for their own schools of dance because of these perceptions are explored. This study was conducted through in-depth interviews and a survey instrument. The participants' narratives…

An Emphasis on Perception: Teaching Image Formation Using a Mechanistic Model of Vision.

ERIC Educational Resources Information Center

Allen, Sue; And Others

An effective way to teach the concept of image is to give students a model of human vision which incorporates a simple mechanism of depth perception. In this study two almost identical versions of a curriculum in geometrical optics were created. One used a mechanistic, interpretive eye model, and in the other the eye was modeled as a passive,…

Cognition and the Brain

DTIC Science & Technology

1991-05-10

extrasensory areas, where the transfer is mediated by activity in the hippocampus. One of the objectives of this proposed research is to determine...Visual Perception : The Neurophysiological Foundations, Academic, New York, 1989. .󈧻] M. Livingstone and D. Ilubel. Segregation of form, color, movement...and depth: Anatomy, physiology, and perception . Science, 240:740-749, 1988. 56: M. S. Livingstone and D. H. Hubel. Anatomy and physiology of a color

Food and Personal Hygiene Perceptions and Practices among Caregivers Whose Children Have Diarrhea: A Qualitative Study of Urban Mothers in Tangerang, Indonesia

ERIC Educational Resources Information Center

Usfar, Avita A.; Iswarawanti, Dwi N.; Davelyna, Devy; Dillon, Drupadi

2010-01-01

Objective: To examine caregivers' perceptions and practices related to food and personal hygiene and its association with diarrhea in children 6 to 36 months of age who suffered recurrent diarrhea. Design: This qualitative study, conducted in March and April 2006, used both in-depth interviews and direct observation data. Setting: Urban Tangerang,…

An Exploratory Study of GP Perceptions of the Impact of a Primary Care Counselling Service on Their Practice

ERIC Educational Resources Information Center

Schafer, Tim; Amoateng, Geoffrey; Wrycraft, Nick

2009-01-01

This paper presents the results of research into GP perceptions of the impact of on-site counselling on general practice. The research is part of a larger evaluation of a local enhanced primary care mental service. The initial survey and in-depth interviews with GPs reported here focused on the pre-existing counselling service. The results suggest…

Holistic processing of impossible objects: evidence from Garner's speeded-classification task.

PubMed

Freud, Erez; Avidan, Galia; Ganel, Tzvi

2013-12-18

Holistic processing, the decoding of the global structure of a stimulus while the local parts are not explicitly represented, is a basic characteristic of object perception. The current study was aimed to test whether such a representation could be created even for objects that violate fundamental principles of spatial organization, namely impossible objects. Previous studies argued that these objects cannot be represented holistically in long-term memory because they lack coherent 3D structure. Here, we utilized Garner's speeded classification task to test whether the perception of possible and impossible objects is mediated by similar holistic processing mechanisms. To this end, participants were asked to make speeded classifications of one object dimension while an irrelevant dimension was kept constant (baseline condition) or when this dimension varied (filtering condition). It is well accepted that ignoring the irrelevant dimension is impossible when holistic perception is mandatory, thus the extent of Garner interference in performance between the baseline and filtering conditions serves as an index of holistic processing. Critically, in Experiment 1, similar levels of Garner interference were found for possible and impossible objects implying holistic perception of both object types. Experiment 2 extended these results and demonstrated that even when depth information was explicitly processed, participants were still unable to process one dimension (width/depth) while ignoring the irrelevant dimension (depth/width, respectively). The results of Experiment 3 replicated the basic pattern found in Experiments 1 and 2 using a novel set of object exemplars. In Experiment 4, we used possible and impossible versions of the Penrose triangles in which information about impossibility is embedded in the internal elements of the objects which participant were explicitly asked to judge. As in Experiments 1-3, similar Garner interference was found for possible and impossible objects. Taken together, these findings emphasize the centrality of holistic processing style in object perception and suggest that it applies even for atypical stimuli such as impossible objects. Copyright © 2013 Elsevier B.V. All rights reserved.

Automatically Characterizing Sensory-Motor Patterns Underlying Reach-to-Grasp Movements on a Physical Depth Inversion Illusion.

PubMed

Nguyen, Jillian; Majmudar, Ushma V; Ravaliya, Jay H; Papathomas, Thomas V; Torres, Elizabeth B

2015-01-01

Recently, movement variability has been of great interest to motor control physiologists as it constitutes a physical, quantifiable form of sensory feedback to aid in planning, updating, and executing complex actions. In marked contrast, the psychological and psychiatric arenas mainly rely on verbal descriptions and interpretations of behavior via observation. Consequently, a large gap exists between the body's manifestations of mental states and their descriptions, creating a disembodied approach in the psychological and neural sciences: contributions of the peripheral nervous system to central control, executive functions, and decision-making processes are poorly understood. How do we shift from a psychological, theorizing approach to characterize complex behaviors more objectively? We introduce a novel, objective, statistical framework, and visuomotor control paradigm to help characterize the stochastic signatures of minute fluctuations in overt movements during a visuomotor task. We also quantify a new class of covert movements that spontaneously occur without instruction. These are largely beneath awareness, but inevitably present in all behaviors. The inclusion of these motions in our analyses introduces a new paradigm in sensory-motor integration. As it turns out, these movements, often overlooked as motor noise, contain valuable information that contributes to the emergence of different kinesthetic percepts. We apply these new methods to help better understand perception-action loops. To investigate how perceptual inputs affect reach behavior, we use a depth inversion illusion (DII): the same physical stimulus produces two distinct depth percepts that are nearly orthogonal, enabling a robust comparison of competing percepts. We find that the moment-by-moment empirically estimated motor output variability can inform us of the participants' perceptual states, detecting physiologically relevant signals from the peripheral nervous system that reveal internal mental states evoked by the bi-stable illusion. Our work proposes a new statistical platform to objectively separate changes in visual perception by quantifying the unfolding of movement, emphasizing the importance of including in the motion analyses all overt and covert aspects of motor behavior.

"Disruptive Technologies", "Pedagogical Innovation": What's New? Findings from an In-Depth Study of Students' Use and Perception of Technology

ERIC Educational Resources Information Center

Conole, Grainne; de Laat, Maarten; Dillon, Teresa; Darby, Jonathan

2008-01-01

The paper describes the findings from a study of students' use and experience of technologies. A series of in-depth case studies were carried out across four subject disciplines, with data collected via survey, audio logs and interviews. The findings suggest that students are immersed in a rich, technology-enhanced learning environment and that…

Extremal edges: a powerful cue to depth perception and figure-ground organization.

PubMed

Palmer, Stephen E; Ghose, Tandra

2008-01-01

Extremal edges (EEs) are projections of viewpoint-specific horizons of self-occlusion on smooth convex surfaces. An ecological analysis of viewpoint constraints suggests that an EE surface is likely to be closer to the observer than the non-EE surface on the other side of the edge. In two experiments, one using shading gradients and the other using texture gradients, we demonstrated that EEs operate as strong cues to relative depth perception and figure-ground organization. Image regions with an EE along the shared border were overwhelmingly perceived as closer than either flat or equally convex surfaces without an EE along that border. A further demonstration suggests that EEs are more powerful than classical figure-ground cues, including even the joint effects of small size, convexity, and surroundedness.

Deeper Cochlear Implant Electrode Insertion Angle Improves Detection of Musical Sound Quality Deterioration Related to Bass Frequency Removal.

PubMed

Roy, Alexis T; Penninger, Richard T; Pearl, Monica S; Wuerfel, Waldemar; Jiradejvong, Patpong; Carver, Courtney; Buechner, Andreas; Limb, Charles J

2016-02-01

Cochlear implant (CI) electrode arrays typically do not reach the most apical regions of the cochlea that intrinsically encode low frequencies. This may contribute to diminished implant-mediated musical sound quality perception. The objective of this study was to assess the effect of varying degrees of apical cochlear stimulation (measured by angular insertion depth) on musical sound quality discrimination. Increased apical cochlear stimulation will improve low-frequency perception and musical sound quality discrimination. Standard (31.5 mm, n = 17) and medium (24 mm, n = 8) array Med-EL CI users, and normal hearing (NH) listeners (n = 16) participated. Imaging confirmed angular insertion depth. Participants completed a musical discrimination task in which they listened to a real-world musical stimulus (labeled reference) and provided sound quality ratings to versions of the reference, which included a hidden reference and test stimuli with increasing amounts of low-frequency removal. Scores for each CI users were calculated on the basis of how much their ratings differed from NH listeners for each stimulus version. Medium array and standard users had significantly different insertion depths (389.4 ± 64.5 and 583.9 ± 78.5 degrees, respectively; p <  .001). A significant Pearson's correlation was observed between angular insertion depth and the hidden reference scores (p < 0.05). CI users with greater apical stimulation made sound quality discriminations that more closely resembled those of NH controls for stimuli that contained low frequencies (< 200 Hz of information). These findings suggest that increased apical cochlear stimulation improves musical low-frequency perception, which may provide a more satisfactory music listening experience for CI users.

"Adging up" to "Beef on Sight": A Qualitative Study of the Perceived Causes of Interpersonal Conflict and Violence among African-American Girls in an Urban High School

ERIC Educational Resources Information Center

Cameron, Mark; Taggar, Carolyn E.

2005-01-01

This qualitative study examined perceptions of the causes and nature of conflicts and violence among African-American girls in an urban high school. In-depth, iterative interviewing was used to explore the perceptions of these girls, male students, teachers, and other school personnel. Ethnographic observation was also used. Conflicts and violence…

Combining Causal Model and Focus Group Discussions Experiences Learned from a Socio-Anthropological Research on the Differing Perceptions of Caretakers and Health Professionals on Children's Health (Bolivia/Peru)

ERIC Educational Resources Information Center

Lefevre, Pierre; de Suremain, Charles-Edouard; Rubin de Celis, Emma; Sejas, Edgar

2004-01-01

The paper discusses the utility of constructing causal models in focus groups. This was experienced as a complement to an in-depth ethnographic research on the differing perceptions of caretakers and health professionals on child's growth and development in Peru and Bolivia. The rational, advantages, difficulties and necessary adaptations of…

Teachers' Perceptions of the Use of Computer Assisted Language Learning to Develop Children's Reading Skills in English as a Second Language in the United Arab Emirates

ERIC Educational Resources Information Center

Al-Awidi, Hamed Mubarak; Ismail, Sadiq Abdulwahed

2014-01-01

This study investigated ESL teachers' perceptions regarding the use of Computer Assisted Language Learning (CALL) in teaching reading to children. A random sample of 145 teachers participated in the study by completing a survey developed by the researchers. To explore the situation in depth, 16 teachers were later interviewed. Results indicated…

Chiari Malformation: Symptoms

MedlinePlus

... hands Fatigue Nausea Shortness of breath Blurred Vision Tinnitus Difficulty swallowing Leg weakness % 98 84 72 69 ... system) may not work properly, which may cause tinnitus (ringing in the ears), depth perception, running into ...

A one-size-fits-all HIV prevention and education approach?: Analyzing and interpreting divergent HIV risk perceptions between African American and East African immigrant women in Washington, DC

PubMed Central

De Jesus, Maria; Taylor, Juanita; Maine, Cathleen; Nalls, Patricia

2015-01-01

Background To date, there are very few comparative US studies and none in DC that distinguish between US-born and foreign-born Black women to examine and compare their perceptions of HIV risk. This qualitative study, therefore, analyzes African American and East African women’s perceptions of HIV risk in the Washington DC Metropolitan area, which has the highest AIDS rate in the US. Methods Forty in-depth, semi-structured interviews and 10 cognitive interviews were conducted among a sample of 25 African American women and 25 East African born women between October 2012 and March 2013 to examine perceptions regarding HIV risk. The in-depth semi-structured interviews were preceded by the cognitive interviews and accompanying survey. Study protocol was reviewed and approved by the American University Institutional Review Board. Results Adopting Boerma and Weir’s Proximate Determinants conceptual framework to interpret the data, the results of the study demonstrate that African American and East African immigrant women have divergent perceptions of HIV risk. While African American women ascribe HIV risk to individual-level behaviors and choices such as unprotected sex, East African women attribute HIV risk to conditions of poverty and survival. Conclusions Study findings suggest that addressing HIV prevention and education among Black women in DC will require distinct and targeted strategies that are culturally and community-centered in order to resonate with these different audiences. PMID:26766523

A One-Size-Fits-All HIV Prevention and Education Approach?: Interpreting Divergent HIV Risk Perceptions Between African American and East African Immigrant Women in Washington, DC Using the Proximate-Determinants Conceptual Framework.

PubMed

De Jesus, Maria; Taylor, Juanita; Maine, Cathleen; Nalls, Patricia

2016-02-01

To date, there are very few comparative US studies and none in DC that distinguish between US-born and foreign-born black women to examine and compare their perceptions of HIV risk. This qualitative study, therefore, analyzes African American and East African women's perceptions of HIV risk in the Washington DC Metropolitan area, which has the highest AIDS rate in the United States. Forty in-depth, semistructured interviews and 10 cognitive interviews were conducted among a sample of 25 African American women and 25 East African born women between October 2012 and March 2013 to examine perceptions regarding HIV risk. The in-depth semistructured interviews were preceded by the cognitive interviews and accompanying survey. Study protocol was reviewed and approved by the American University Institutional Review Board. Adopting Boerma and Weir's Proximate Determinants conceptual framework to interpret the data, the results of the study demonstrate that African American and East African immigrant women have divergent perceptions of HIV risk. Although African American women ascribe HIV risk to individual-level behaviors and choices such as unprotected sex, East African women attribute HIV risk to conditions of poverty and survival. Study findings suggest that addressing HIV prevention and education among black women in DC will require distinct and targeted strategies that are culturally and community-centered to resonate with these different audiences.

Perceptions and uses of plants for reproductive health among traditional midwives in Ecuador: moving towards intercultural pharmacological practices.

PubMed

Torri, Maria Costanza

2013-07-01

Despite the fact that plants have played an important role in midwifery in many cultures, there are very few in-depth studies on the plants traditionally used by midwives. The aim of this study is to analyse the perceptions and the uses of medicinal plants for reproductive health among indigenous midwives in the city of Otavalo, Ecuador. The article also aims to analyse the perceptions of traditional midwives regarding allopathic drugs for reproductive health and their possible overlapping uses of medicinal plants and allopathic drugs. The data are drawn from an ethnographic study carried out in Ecuador. In total, 20 traditional midwives have been interviewed. Individual and in-depth interviews also took place with a sample of 35 women as well as with five nurses and two doctors working at San Luis Hospital in Otavalo. The study shows that cultural health management and the incorporation of the beliefs and practices relating to women's reproductive health can represent a starting point towards the search for more successful strategies in reproductive health. Copyright © 2012 Elsevier Ltd. All rights reserved.

Psychophysical Studies of Visual Cortical Function

DTIC Science & Technology

1992-01-12

principle of generic image samplin& a hypothesis which provides ageometric tool to understand visual surface learning. We also have investigated the...perception of depth from unpaired points ( DaVinci stereopsis), showing that such points lead to depth andsubjective contours. In color filling in, we have...outlined and systematized a number of important phenomenon which we label under the rubric of DaVinci stereopsis. We summarize these results in a number of

Using the stereokinetic effect to convey depth - Computationally efficient depth-from-motion displays

NASA Technical Reports Server (NTRS)

Kaiser, Mary K.; Proffitt, Dennis R.

1992-01-01

Recent developments in microelectronics have encouraged the use of 3D data bases to create compelling volumetric renderings of graphical objects. However, even with the computational capabilities of current-generation graphical systems, real-time displays of such objects are difficult, particularly when dynamic spatial transformations are involved. In this paper we discuss a type of visual stimulus (the stereokinetic effect display) that is computationally far less complex than a true three-dimensional transformation but yields an equally compelling depth impression, often perceptually indiscriminable from the true spatial transformation. Several possible applications for this technique are discussed (e.g., animating contour maps and air traffic control displays so as to evoke accurate depth percepts).

Displays. [three dimensional analog visual system for aiding pilot space perception

NASA Technical Reports Server (NTRS)

1974-01-01

An experimental investigation made to determine the depth cue of a head movement perspective and image intensity as a function of depth is summarized. The experiment was based on the use of a hybrid computer generated contact analog visual display in which various perceptual depth cues are included on a two dimensional CRT screen. The system's purpose was to impart information, in an integrated and visually compelling fashion, about the vehicle's position and orientation in space. Results show head movement gives a 40% improvement in depth discrimination when the display is between 40 and 100 cm from the subject; intensity variation resulted in as much improvement as head movement.

On the anisotropy of perceived ground extents and the interpretation of walked distance as a measure of perception

PubMed Central

Li, Zhi; Sun, Emily; Strawser, Cassandra J.; Spiegel, Ariana; Klein, Brennan; Durgin, Frank H.

2012-01-01

Two experiments are reported concerning the perception of ground extent in order to discover whether prior reports of anisotropy between frontal extents and extents in depth were consistent across different measures (visual matching and pantomime walking) and test environments (outdoor environments and virtual environments). In Experiment 1 it was found that depth extents of up to 7 m are indeed perceptually compressed relative to frontal extents in an outdoor environment, and that perceptual matching provided more precise estimates than did pantomime walking. In Experiment 2, similar anisotropies were found using similar tasks in a similar (but virtual) environment. In both experiments pantomime walking measures seemed to additionally compress the range of responses. Experiment 3 supported the hypothesis that range compression in walking measures of perceived distance might be due to proactive interference (memory contamination). It is concluded that walking measures are calibrated for perceived egocentric distance, but that pantomime walking measures may suffer range compression. Depth extents along the ground are perceptually compressed relative to frontal ground extents in a manner consistent with the angular scale expansion hypothesis. PMID:22889186

Sigmund Exner's (1887) Einige Beobachtungen über Bewegungsnachbilder (Some Observations on Movement Aftereffects): An Illustrated Translation With Commentary.

PubMed

Verstraten, Frans A J; Niehorster, Diederick C; van de Grind, Wim A; Wade, Nicholas J

2015-10-01

In his original contribution, Exner's principal concern was a comparison between the properties of different aftereffects, and particularly to determine whether aftereffects of motion were similar to those of color and whether they could be encompassed within a unified physiological framework. Despite the fact that he was unable to answer his main question, there are some excellent-so far unknown-contributions in Exner's paper. For example, he describes observations that can be related to binocular interaction, not only in motion aftereffects but also in rivalry. To the best of our knowledge, Exner provides the first description of binocular rivalry induced by differently moving patterns in each eye, for motion as well as for their aftereffects. Moreover, apart from several known, but beautifully addressed, phenomena he makes a clear distinction between motion in depth based on stimulus properties and motion in depth based on the interpretation of motion. That is, the experience of movement, as distinct from the perception of movement. The experience, unlike the perception, did not result in a motion aftereffect in depth.

Sigmund Exner’s (1887) Einige Beobachtungen über Bewegungsnachbilder (Some Observations on Movement Aftereffects): An Illustrated Translation With Commentary

PubMed Central

Niehorster, Diederick C.; van de Grind, Wim A.; Wade, Nicholas J.

2015-01-01

In his original contribution, Exner’s principal concern was a comparison between the properties of different aftereffects, and particularly to determine whether aftereffects of motion were similar to those of color and whether they could be encompassed within a unified physiological framework. Despite the fact that he was unable to answer his main question, there are some excellent—so far unknown—contributions in Exner’s paper. For example, he describes observations that can be related to binocular interaction, not only in motion aftereffects but also in rivalry. To the best of our knowledge, Exner provides the first description of binocular rivalry induced by differently moving patterns in each eye, for motion as well as for their aftereffects. Moreover, apart from several known, but beautifully addressed, phenomena he makes a clear distinction between motion in depth based on stimulus properties and motion in depth based on the interpretation of motion. That is, the experience of movement, as distinct from the perception of movement. The experience, unlike the perception, did not result in a motion aftereffect in depth. PMID:27648213

The Limits of Human Stereopsis in Space and Time

PubMed Central

Kane, David; Guan, Phillip

2014-01-01

To encode binocular disparity, the visual system determines the image patches in one eye that yield the highest correlation with patches in the other eye. The computation of interocular correlation occurs after spatiotemporal filtering of monocular signals, which leads to restrictions on disparity variations that can support depth perception. We quantified those restrictions by measuring humans' ability to see disparity variation at a wide range of spatial and temporal frequencies. Lower-disparity thresholds cut off at very low spatiotemporal frequencies, which is consistent with the behavior of V1 neurons. Those thresholds are space–time separable, suggesting that the underlying neural mechanisms are separable. We also found that upper-disparity limits were characterized by a spatiotemporal, disparity-gradient limit; to be visible, disparity variation cannot exceed a fixed amount for a given interval in space–time. Our results illustrate that the disparity variations that humans can see are very restricted compared with the corresponding luminance variations. The results also provide insight into the neural mechanisms underlying depth from disparity, such as why stimuli with long interocular delays can still yield clear depth percepts. PMID:24453329

Fibromyalgia Pain: Options for Coping

MedlinePlus

... to ourselves inside our heads can affect our perception of pain. Turning negative thoughts into positive ones ... org/diseases-conditions/fibromyalgia/in-depth/fibromyalgia-pain/ART-20047867 . Mayo Clinic Footer Legal Conditions and Terms ...

Pregnancy Loss: How to Cope

MedlinePlus

... J, et al. A national survey on public perceptions of miscarriage. Obstetrics & Gynecology. 2015;125:1313. Kropmans ... conditions/pregnancy-loss-miscarriage/in-depth/pregnancy-loss/art-20047983 . Mayo Clinic Footer Legal Conditions and Terms ...

Understanding Your Vision: The "Imperfect Eye"

MedlinePlus

... including peripheral awareness (side vision), eye coordination, depth perception, focusing ability, and color vision that make up ... the conditions for which you may be at risk." — Dr. Emily Chew National Eye Institute Farsighted If ...

The Effect of Looming and Receding Sounds on the Perceived In-Depth Orientation of Depth-Ambiguous Biological Motion Figures

PubMed Central

Schouten, Ben; Troje, Nikolaus F.; Vroomen, Jean; Verfaillie, Karl

2011-01-01

Background The focus in the research on biological motion perception traditionally has been restricted to the visual modality. Recent neurophysiological and behavioural evidence, however, supports the idea that actions are not represented merely visually but rather audiovisually. The goal of the present study was to test whether the perceived in-depth orientation of depth-ambiguous point-light walkers (plws) is affected by the presentation of looming or receding sounds synchronized with the footsteps. Methodology/Principal Findings In Experiment 1 orthographic frontal/back projections of plws were presented either without sound or with sounds of which the intensity level was rising (looming), falling (receding) or stationary. Despite instructions to ignore the sounds and to only report the visually perceived in-depth orientation, plws accompanied with looming sounds were more often judged to be facing the viewer whereas plws paired with receding sounds were more often judged to be facing away from the viewer. To test whether the effects observed in Experiment 1 act at a perceptual level rather than at the decisional level, in Experiment 2 observers perceptually compared orthographic plws without sound or paired with either looming or receding sounds to plws without sound but with perspective cues making them objectively either facing towards or facing away from the viewer. Judging whether either an orthographic plw or a plw with looming (receding) perspective cues is visually most looming becomes harder (easier) when the orthographic plw is paired with looming sounds. Conclusions/Significance The present results suggest that looming and receding sounds alter the judgements of the in-depth orientation of depth-ambiguous point-light walkers. While looming sounds are demonstrated to act at a perceptual level and make plws look more looming, it remains a challenge for future research to clarify at what level in the processing hierarchy receding sounds affect how observers judge the in-depth perception of plws. PMID:21373181

Digital science games' impact on sixth and eighth graders' perceptions of science

NASA Astrophysics Data System (ADS)

Peng, Li-Wei

2009-12-01

The quasi-experimental study investigated sixth and eighth graders' perceptions of science with gender, grade levels, and educational experiences as the variables. The Theory of Planned Behavior (Ajzen, 1985) claims that attitude toward the behavior, subjective norm, and perceived behavioral control play a major role in people's intentions, and these intentions ultimately impact their behavior. The study adopted a quantitative research approach by conducting a science perceptions survey for examining students' self-efficacy in learning science (i.e., perceived behavioral control), value of science (i.e., attitude toward the behavior), motivation in science (i.e., attitude toward the behavior), and perceptions of digital science games in science classes (i.e., perceived behavioral control). A total of 255 participants' responses from four rural Appalachian middle school science classrooms in southeastern Ohio were analyzed through a three-way ANCOVA factorial pre-test and post-test data analysis with experimental and comparison groups. Additionally, the study applied a semi-structured, in-depth interview as a qualitative research approach to further examine STEAM digital science games' and Fellows' impact on students' perceptions of science. Eight students in the experimental group were interviewed. Interview data were analyzed with an inductive method. The results found in the three-way ANCOVA data analysis indicated that the diversity of educational experiences was a significant factor that impacted sixth and eighth graders' perceptions of science. Additionally, the interaction of gender and educational experiences was another significant factor that impacted sixth and eighth graders' perceptions of science. The findings of the two short-answer questions identified the reasons why the participants liked or disliked science, as well as why the participants would or would not choose a career in science. The conclusions of the semi-structured, in-depth interview supported that the interviewees' perceptions of the STEAM digital science games and Fellows ranged from neutral to positive. Seven out of eight of the interviewees commented that the STEAM digital science games and Fellows enhanced the interviewees' perceptions of science and their choice of careers. Five out of eight of the interviewees intended to have careers in science.

Index to FAA Office of Aerospace Medicine Reports: 1961 Through 2006

DTIC Science & Technology

2007-01-01

Research Branch) has always comprised a group of research teams identified primarily by their specialty func- tions. In 2001, CAMI was renamed the...implications of unmanned aircraft accidents: Flight control problems. Above: This is an entry from the Chronological Index of research reports, shown... control research task. AD660198 65-32 Gogel WC, Mertens HW: Problems in depth perception: A method of simulating objects moving in depth. AD660171 1966 66

Therapists' Perceptions of Their Encounter With Sex Offenders.

PubMed

Elias, Haneen; Haj-Yahia, Muhammad M

2017-08-01

Despite the increasing interest in therapists' responses to their encounter with sex offenders, there is a lack of research on their subjective perceptions of this encounter and on their experience working with this client population. The study presented in this article is part of a larger qualitative research project conducted among 19 social workers (12 were women and 7 were men; their ages ranged from 30 to 66 years; 15 of them were Jewish and 4 were Arab). In-depth semi-structured interviews were conducted to examine their attitudes toward and perceptions of their encounter with sex offenders. The questions related to the therapists' perceptions regarding motives for committing sex offenses, therapists' perceptions of sex offenders, therapists' perceptions of the victims of sex offenders, and therapists' perceptions of the nature of their professional role. In this article, emphasis is placed on the development and changes of the therapists' perceptions following that encounter. The following five major domains of perceptions were revealed in the study: Therapists' perceptions of the offenders' personal motives for committing sex offenses, therapists' perceptions of sex offenders, therapists' perceptions of the experience of victimization, the process of changing perceptions, and the nature of the therapists' role. The results are discussed in light of Ajzen's conceptualization of the process of acquiring beliefs. The limitations of the study as well as its implications for future research and for shaping the perceptions of therapists toward sex offenders are discussed.

Developmental milestones record - 9 months

MedlinePlus

... Feeds self with fingers Throws or shakes objects SENSORY AND COGNITIVE SKILLS The 9-month-old typically: Babbles Has separation anxiety and may cling to parents Is developing depth perception Understands that objects continue to exist, even when ...

Flood Realities, Perceptions and the Depth of Divisions on Climate

PubMed Central

Hamilton, Lawrence C; Wake, Cameron P; Hartter, Joel; Safford, Thomas G; Puchlopek, Alli J

2016-01-01

Research has led to broad agreement among scientists that anthropogenic climate change is happening now and likely to worsen. In contrast to scientific agreement, US public views remain deeply divided, largely along ideological lines. Science communication has been neutralised in some arenas by intense counter-messaging, but as adverse climate impacts become manifest they might intervene more persuasively in local perceptions. We look for evidence of this occurring with regard to realities and perceptions of flooding in the northeastern US state of New Hampshire. Although precipitation and flood damage have increased, with ample news coverage, most residents do not see a trend. Nor do perceptions about past and future local flooding correlate with regional impacts or vulnerability. Instead, such perceptions follow ideological patterns resembling those of global climate change. That information about the physical world can be substantially filtered by ideology is a common finding from sociological environment/society research. PMID:27818533

Do knowledge and cultural perceptions of modern female contraceptives predict male involvement in Ayete, Nigeria?

PubMed

Sanusi, A; Akinyemi, Oluwaseun O; Onoviran, Oghemetega O

2014-12-01

Male involvement is crucial to female contraceptive use. This study examined how male knowledge and cultural perceptions of modern female contraceptives influence involvement in contraceptive use. A cross-sectional survey of 389 men from Ayete, Nigeria was used to regress a continuous male involvement score on demographic variables, knowledge of at least one method of modern female contraception and a scored male perception variable using Ordinary Least Squares regression. Controlling for perception, the knowledge of at least one method of modern female contraception was not significantly associated with a change in male involvement (p=0.264). Increasing positive perception was associated with higher male involvement scores (p=0.001). Higher educated males, those with a current desire to have children and males whose partners were currently using a method had greater male involvement scores (p<0.05). Policy and intervention efforts should be focused on changing cultural perceptions, in addition to providing in-depth knowledge of contraceptive methods.

Index to FAA Office of Aerospace Medicine Reports: 1961 Through 2012

DTIC Science & Technology

2013-01-01

air traffic control research task. AD660198 65-32 Gogel WC, Mertens HW: Problems in depth perception: A method of simulating objects moving in depth...ADA092529/7 80-14 Smith RC: Stress, anxiety, and the air traffic control specialist: Some conclusions from a decade of research . ADA093266/5 80-15...PS, Manning CA: Selection of air traffic controllers for automated systems: applications from current research . ADA230058 90-14 Parker JF Jr, Shepherd

Perception of stochastic envelopes by normal-hearing and cochlear-implant listeners

PubMed Central

Gomersall, Philip A.; Turner, Richard E.; Baguley, David M.; Deeks, John M.; Gockel, Hedwig E.; Carlyon, Robert P.

2016-01-01

We assessed auditory sensitivity to three classes of temporal-envelope statistics (modulation depth, modulation rate, and comodulation) that are important for the perception of ‘sound textures’. The textures were generated by a probabilistic model that prescribes the temporal statistics of a selected number of modulation envelopes, superimposed onto noise carriers. Discrimination thresholds were measured for normal-hearing (NH) listeners and users of a MED-EL pulsar cochlear implant (CI), for separate manipulations of the average rate and modulation depth of the envelope in each frequency band of the stimulus, and of the co-modulation between bands. Normal-hearing (NH) listeners' discrimination of envelope rate was similar for baseline modulation rates of 5 and 34 Hz, and much poorer than previously reported for sinusoidally amplitude-modulated sounds. In contrast, discrimination of model parameters that controlled modulation depth was poorer at the lower baseline rate, consistent with the idea that, at the lower rate, subjects get fewer ‘looks’ at the relevant information when comparing stimuli differing in modulation depth. NH listeners could discriminate differences in co-modulation across bands; a multidimensional scaling study revealed that this was likely due to genuine across-frequency processing, rather than within-channel cues. CI users' discrimination performance was worse overall than for NH listeners, but showed a similar dependence on stimulus parameters. PMID:26706708

Segregation of Form, Color, Movement, and Depth: Anatomy, Physiology, and Perception.

ERIC Educational Resources Information Center

Livingstone, Margaret; Hubel, David

1988-01-01

Summarizes the anatomical, physiological, and psychological evidence related to the primate visual system. States that comparison of perceptual abilities with the electrophysiological properties of neurons may help deduce functions of visual areas. (RT)

Frequency preference and attention effects across cortical depths in the human primary auditory cortex.

PubMed

De Martino, Federico; Moerel, Michelle; Ugurbil, Kamil; Goebel, Rainer; Yacoub, Essa; Formisano, Elia

2015-12-29

Columnar arrangements of neurons with similar preference have been suggested as the fundamental processing units of the cerebral cortex. Within these columnar arrangements, feed-forward information enters at middle cortical layers whereas feedback information arrives at superficial and deep layers. This interplay of feed-forward and feedback processing is at the core of perception and behavior. Here we provide in vivo evidence consistent with a columnar organization of the processing of sound frequency in the human auditory cortex. We measure submillimeter functional responses to sound frequency sweeps at high magnetic fields (7 tesla) and show that frequency preference is stable through cortical depth in primary auditory cortex. Furthermore, we demonstrate that-in this highly columnar cortex-task demands sharpen the frequency tuning in superficial cortical layers more than in middle or deep layers. These findings are pivotal to understanding mechanisms of neural information processing and flow during the active perception of sounds.

Perceptual Calibration for Immersive Display Environments

PubMed Central

Ponto, Kevin; Gleicher, Michael; Radwin, Robert G.; Shin, Hyun Joon

2013-01-01

The perception of objects, depth, and distance has been repeatedly shown to be divergent between virtual and physical environments. We hypothesize that many of these discrepancies stem from incorrect geometric viewing parameters, specifically that physical measurements of eye position are insufficiently precise to provide proper viewing parameters. In this paper, we introduce a perceptual calibration procedure derived from geometric models. While most research has used geometric models to predict perceptual errors, we instead use these models inversely to determine perceptually correct viewing parameters. We study the advantages of these new psychophysically determined viewing parameters compared to the commonly used measured viewing parameters in an experiment with 20 subjects. The perceptually calibrated viewing parameters for the subjects generally produced new virtual eye positions that were wider and deeper than standard practices would estimate. Our study shows that perceptually calibrated viewing parameters can significantly improve depth acuity, distance estimation, and the perception of shape. PMID:23428454

Standardized Patients versus Volunteer Patients for Physical Therapy Students' Interviewing Practice: A Pilot Study.

PubMed

Murphy, Sue; Imam, Bita; MacIntyre, Donna L

2015-01-01

To compare the use of standardized patients (SPs) and volunteer patients (VPs) for physical therapy students' interviewing practice in terms of students' perception and overall costs. Students in the Master of Physical Therapy programme (n=80) at a Canadian university were divided into 20 groups of 4 and were randomly assigned to interview either an SP (10 groups) or a VP (10 groups). Students completed a survey about their perception of the usefulness of the activity and the ease and depth of information extraction. Survey responses as well as costs of the interview exercise were compared between SP and VP groups. No statistically significant between-groups difference was found for the majority of survey items. The cost of using an SP was $148, versus $50 for a VP. Students' perceptions of the usefulness of the activity in helping them to develop their interview skills and of the ease and depth of extracting information were similar for both SPs and VPs. Because the cost of using an SP is about three times that of using a VP, using VPs seem to be a more cost-effective option.

A neural model of visual figure-ground segregation from kinetic occlusion.

PubMed

Barnes, Timothy; Mingolla, Ennio

2013-01-01

Freezing is an effective defense strategy for some prey, because their predators rely on visual motion to distinguish objects from their surroundings. An object moving over a background progressively covers (deletes) and uncovers (accretes) background texture while simultaneously producing discontinuities in the optic flow field. These events unambiguously specify kinetic occlusion and can produce a crisp edge, depth perception, and figure-ground segmentation between identically textured surfaces--percepts which all disappear without motion. Given two abutting regions of uniform random texture with different motion velocities, one region appears to be situated farther away and behind the other (i.e., the ground) if its texture is accreted or deleted at the boundary between the regions, irrespective of region and boundary velocities. Consequently, a region with moving texture appears farther away than a stationary region if the boundary is stationary, but it appears closer (i.e., the figure) if the boundary is moving coherently with the moving texture. A computational model of visual areas V1 and V2 shows how interactions between orientation- and direction-selective cells first create a motion-defined boundary and then signal kinetic occlusion at that boundary. Activation of model occlusion detectors tuned to a particular velocity results in the model assigning the adjacent surface with a matching velocity to the far depth. A weak speed-depth bias brings faster-moving texture regions forward in depth in the absence of occlusion (shearing motion). These processes together reproduce human psychophysical reports of depth ordering for key cases of kinetic occlusion displays. Copyright © 2012 Elsevier Ltd. All rights reserved.

EFL Teachers' Perceptions of Continuing Professional Development: A Case of Iranian High School Teachers (La percepción de docentes de inglés como lengua extranjera acerca del desarrollo profesional continuado: el caso de profesores iraníes de bachillerato)

ERIC Educational Resources Information Center

Alibakhshi, Goudarz; Dehvari, Najibeh

2015-01-01

English, particularly regarding a foreign language teachers' professional development, has been studied in depth. However, it is not known how Iranian English as a foreign language teachers perceive continuing professional development. This study explored the perceptions of Iranian English as a foreign language teachers of continuing professional…

Absolute Depth Sensitivity in Cat Primary Visual Cortex under Natural Viewing Conditions.

PubMed

Pigarev, Ivan N; Levichkina, Ekaterina V

2016-01-01

Mechanisms of 3D perception, investigated in many laboratories, have defined depth either relative to the fixation plane or to other objects in the visual scene. It is obvious that for efficient perception of the 3D world, additional mechanisms of depth constancy could operate in the visual system to provide information about absolute distance. Neurons with properties reflecting some features of depth constancy have been described in the parietal and extrastriate occipital cortical areas. It has also been shown that, for some neurons in the visual area V1, responses to stimuli of constant angular size differ at close and remote distances. The present study was designed to investigate whether, in natural free gaze viewing conditions, neurons tuned to absolute depths can be found in the primary visual cortex (area V1). Single-unit extracellular activity was recorded from the visual cortex of waking cats sitting on a trolley in front of a large screen. The trolley was slowly approaching the visual scene, which consisted of stationary sinusoidal gratings of optimal orientation rear-projected over the whole surface of the screen. Each neuron was tested with two gratings, with spatial frequency of one grating being twice as high as that of the other. Assuming that a cell is tuned to a spatial frequency, its maximum response to the grating with a spatial frequency twice as high should be shifted to a distance half way closer to the screen in order to attain the same size of retinal projection. For hypothetical neurons selective to absolute depth, location of the maximum response should remain at the same distance irrespective of the type of stimulus. It was found that about 20% of neurons in our experimental paradigm demonstrated sensitivity to particular distances independently of the spatial frequencies of the gratings. We interpret these findings as an indication of the use of absolute depth information in the primary visual cortex.

Stereomotion is processed by the third-order motion system: reply to comment on Three-systems theory of human visual motion perception: review and update

NASA Astrophysics Data System (ADS)

Lu, Zhong-Lin; Sperling, George

2002-10-01

Two theories are considered to account for the perception of motion of depth-defined objects in random-dot stereograms (stereomotion). In the LuSperling three-motion-systems theory J. Opt. Soc. Am. A 18 , 2331 (2001), stereomotion is perceived by the third-order motion system, which detects the motion of areas defined as figure (versus ground) in a salience map. Alternatively, in his comment J. Opt. Soc. Am. A 19 , 2142 (2002), Patterson proposes a low-level motion-energy system dedicated to stereo depth. The critical difference between these theories is the preprocessing (figureground based on depth and other cues versus simply stereo depth) rather than the motion-detection algorithm itself (because the motion-extraction algorithm for third-order motion is undetermined). Furthermore, the ability of observers to perceive motion in alternating feature displays in which stereo depth alternates with other features such as texture orientation indicates that the third-order motion system can perceive stereomotion. This reduces the stereomotion question to Is it third-order alone or third-order plus dedicated depth-motion processing? Two new experiments intended to support the dedicated depth-motion processing theory are shown here to be perfectly accounted for by third-order motion, as are many older experiments that have previously been shown to be consistent with third-order motion. Cyclopean and rivalry images are shown to be a likely confound in stereomotion studies, rivalry motion being as strong as stereomotion. The phase dependence of superimposed same-direction stereomotion stimuli, rivalry stimuli, and isoluminant color stimuli indicates that these stimuli are processed in the same (third-order) motion system. The phase-dependence paradigm Lu and Sperling, Vision Res. 35 , 2697 (1995) ultimately can resolve the question of which types of signals share a single motion detector. All the evidence accumulated so far is consistent with the three-motion-systems theory. 2002 Optical Society of America

Pacman in the sky with shadows: the effect of cast shadows on the perceptual completion of occluded figures by chimpanzees and humans.

PubMed

Tomonaga, Masaki; Imura, Tomoko

2010-07-08

Humans readily perceive whole shapes as intact when some portions of these shapes are occluded by another object. This type of amodal completion has also been widely reported among nonhuman animals and is related to pictorial depth perception. However, the effect of a cast shadow, a critical pictorial-depth cue for amodal completion has been investigated only rarely from the comparative-cognitive perspective. In the present study, we examined this effect in chimpanzees and humans. Chimpanzees were slower in responding to a Pacman target with an occluding square than to the control condition, suggesting that participants perceptually completed the whole circle. When a cast shadow was added to the square, amodal completion occurred in both species. On the other hand, however, critical differences between the species emerged when the cast shadow was added to the Pacman figure, implying that Pacman was in the sky casting a shadow on the square. The cast shadow prevented, to a significant extent, compulsory amodal completion in humans, but had no effect on chimpanzees. These results suggest that cast shadows played a critical role in enabling humans to infer the spatial relationship between Pacman and the square. For chimpanzees, however, a cast shadow may be perceived as another "object". A limited role for cast shadows in the perception of pictorial depth has also been reported with respect to human cognitive development. Further studies on nonhuman primates using a comparative-developmental perspective will clarify the evolutionary origin of the role of cast shadows in visual perception.

Depth cue reliance in surgeons and medical students.

PubMed

Shah, J; Buckley, D; Frisby, J; Darzi, A

2003-09-01

Depth perception is reduced in endoscopic surgery, although little is known about the effect this has on surgical performance. To assess the role of depth cues, 45 subjects completed tests of depth cue reliance. Surgical skill was assessed using the Minimally Invasive Surgical Trainer-Virtual Reality, a previously validated laparoscopic simulator. We could demonstrate no difference in cue reliance for three depth cues--namely stereo, texture, and outline--between surgeons and medical students. Greater dominance on stereo for medical students was a positive finding and a negative finding for the surgeons when correlated with surgical performance. We suggest that surgeons learn to adapt to the nonstereo environment in MIS, and this is the first study to show evidence of this phenomenon. This difference in stereo reliance is a reflection of the experience that surgeons have with laparoscopy compared with medical students, who have none.

Texture and haptic cues in slant discrimination: reliability-based cue weighting without statistically optimal cue combination

NASA Astrophysics Data System (ADS)

Rosas, Pedro; Wagemans, Johan; Ernst, Marc O.; Wichmann, Felix A.

2005-05-01

A number of models of depth-cue combination suggest that the final depth percept results from a weighted average of independent depth estimates based on the different cues available. The weight of each cue in such an average is thought to depend on the reliability of each cue. In principle, such a depth estimation could be statistically optimal in the sense of producing the minimum-variance unbiased estimator that can be constructed from the available information. Here we test such models by using visual and haptic depth information. Different texture types produce differences in slant-discrimination performance, thus providing a means for testing a reliability-sensitive cue-combination model with texture as one of the cues to slant. Our results show that the weights for the cues were generally sensitive to their reliability but fell short of statistically optimal combination - we find reliability-based reweighting but not statistically optimal cue combination.

Perception of approaching and retreating floor-projected shapes in a large, immersive, multimedia learning environment.

PubMed

Dolgov, Igor; Birchfield, David A; McBeath, Michael K; Thornburg, Harvey; Todd, Christopher G

2009-04-01

Perception of floor-projected moving geometric shapes was examined in the context of the Situated Multimedia Arts Learning Laboratory (SMALLab), an immersive, mixed-reality learning environment. As predicted, the projected destinations of shapes which retreated in depth (proximal origin) were judged significantly less accurately than those that approached (distal origin). Participants maintained similar magnitudes of error throughout the session, and no effect of practice was observed. Shape perception in an immersive multimedia environment is comparable to the real world. One may conclude that systematic exploration of basic psychological phenomena in novel mediated environments is integral to an understanding of human behavior in novel human-computer interaction architectures.

The riches of the cyclopean paradigm

NASA Astrophysics Data System (ADS)

Tyler, Christopher W.

2005-03-01

The cyclopean paradigm introduced by Bela Julesz remains one of the richest probes into the neural organization of sensory processing, by virtue of both its specificity for purely stereoscopic form and the sophistication of the processing required to retrieve it. The introduction of the sinusoidal stereograting showed that the perceptual limitations of human depth processing are very different from those for monocular form. Their use has also revealed the existence of hypercyclopean form channels selective for specific aspects of the monocularly invisible depth form. The natural extension of stereogratings to patches of stereoGabor ripple has allowed the measurement of the summation properties for depth structure, which is specific for narrow horizontal bars in depth. Consideration of the apparent motion between two cyclopean depth structures reveals the existence of a novel surface correspondence problem operating for cyclopean surfaces over time after the binocular correspondence has been solved. Such concepts imply that remains to be discovered about cyclopean stereopsis and its relationship to 3D form perception from other depth cues.

Depth image enhancement using perceptual texture priors

NASA Astrophysics Data System (ADS)

Bang, Duhyeon; Shim, Hyunjung

2015-03-01

A depth camera is widely used in various applications because it provides a depth image of the scene in real time. However, due to the limited power consumption, the depth camera presents severe noises, incapable of providing the high quality 3D data. Although the smoothness prior is often employed to subside the depth noise, it discards the geometric details so to degrade the distance resolution and hinder achieving the realism in 3D contents. In this paper, we propose a perceptual-based depth image enhancement technique that automatically recovers the depth details of various textures, using a statistical framework inspired by human mechanism of perceiving surface details by texture priors. We construct the database composed of the high quality normals. Based on the recent studies in human visual perception (HVP), we select the pattern density as a primary feature to classify textures. Upon the classification results, we match and substitute the noisy input normals with high quality normals in the database. As a result, our method provides the high quality depth image preserving the surface details. We expect that our work is effective to enhance the details of depth image from 3D sensors and to provide a high-fidelity virtual reality experience.

Natural-Scene Statistics Predict How the Figure–Ground Cue of Convexity Affects Human Depth Perception

PubMed Central

Fowlkes, Charless C.; Banks, Martin S.

2010-01-01

The shape of the contour separating two regions strongly influences judgments of which region is “figure” and which is “ground.” Convexity and other figure–ground cues are generally assumed to indicate only which region is nearer, but nothing about how much the regions are separated in depth. To determine the depth information conveyed by convexity, we examined natural scenes and found that depth steps across surfaces with convex silhouettes are likely to be larger than steps across surfaces with concave silhouettes. In a psychophysical experiment, we found that humans exploit this correlation. For a given binocular disparity, observers perceived more depth when the near surface's silhouette was convex rather than concave. We estimated the depth distributions observers used in making those judgments: they were similar to the natural-scene distributions. Our findings show that convexity should be reclassified as a metric depth cue. They also suggest that the dichotomy between metric and nonmetric depth cues is false and that the depth information provided many cues should be evaluated with respect to natural-scene statistics. Finally, the findings provide an explanation for why figure–ground cues modulate the responses of disparity-sensitive cells in visual cortex. PMID:20505093

Introducing the depth transfer curve for 3D capture system characterization

NASA Astrophysics Data System (ADS)

Goma, Sergio R.; Atanassov, Kalin; Ramachandra, Vikas

2011-03-01

3D technology has recently made a transition from movie theaters to consumer electronic devices such as 3D cameras and camcorders. In addition to what 2D imaging conveys, 3D content also contains information regarding the scene depth. Scene depth is simulated through the strongest brain depth cue, namely retinal disparity. This can be achieved by capturing an image by horizontally separated cameras. Objects at different depths will be projected with different horizontal displacement on the left and right camera images. These images, when fed separately to either eye, leads to retinal disparity. Since the perception of depth is the single most important 3D imaging capability, an evaluation procedure is needed to quantify the depth capture characteristics. Evaluating depth capture characteristics subjectively is a very difficult task since the intended and/or unintended side effects from 3D image fusion (depth interpretation) by the brain are not immediately perceived by the observer, nor do such effects lend themselves easily to objective quantification. Objective evaluation of 3D camera depth characteristics is an important tool that can be used for "black box" characterization of 3D cameras. In this paper we propose a methodology to evaluate the 3D cameras' depth capture capabilities.

The right hemisphere in esthetic perception.

PubMed

Bromberger, Bianca; Sternschein, Rebecca; Widick, Page; Smith, William; Chatterjee, Anjan

2011-01-01

Little about the neuropsychology of art perception and evaluation is known. Most neuropsychological approaches to art have focused on art production and have been anecdotal and qualitative. The field is in desperate need of quantitative methods if it is to advance. Here, we combine a quantitative approach to the assessment of art with modern voxel-lesion-symptom-mapping methods to determine brain-behavior relationships in art perception. We hypothesized that perception of different attributes of art are likely to be disrupted by damage to different regions of the brain. Twenty participants with right hemisphere damage were given the Assessment of Art Attributes, which is designed to quantify judgments of descriptive attributes of visual art. Each participant rated 24 paintings on 6 conceptual attributes (depictive accuracy, abstractness, emotion, symbolism, realism, and animacy) and 6 perceptual attributes (depth, color temperature, color saturation, balance, stroke, and simplicity) and their interest in and preference for these paintings. Deviation scores were obtained for each brain-damaged participant for each attribute based on correlations with group average ratings from 30 age-matched healthy participants. Right hemisphere damage affected participants' judgments of abstractness, accuracy, and stroke quality. Damage to areas within different parts of the frontal parietal and lateral temporal cortices produced deviation in judgments in four of six conceptual attributes (abstractness, symbolism, realism, and animacy). Of the formal attributes, only depth was affected by inferior prefrontal damage. No areas of brain damage were associated with deviations in interestingness or preference judgments. The perception of conceptual and formal attributes in artwork may in part dissociate from each other and from evaluative judgments. More generally, this approach demonstrates the feasibility of quantitative approaches to the neuropsychology of art.

Reliability of a computer-based system for measuring visual performance skills.

PubMed

Erickson, Graham B; Citek, Karl; Cove, Michelle; Wilczek, Jennifer; Linster, Carolyn; Bjarnason, Brendon; Langemo, Nathan

2011-09-01

Athletes have demonstrated better visual abilities than nonathletes. A vision assessment for an athlete should include methods to evaluate the quality of visual performance skills in the most appropriate, accurate, and repeatable manner. This study determines the reliability of the visual performance measures assessed with a computer-based system, known as the Nike Sensory Station. One hundred twenty-five subjects (56 men, 69 women), age 18 to 30, completed Phase I of the study. Subjects attended 2 sessions, separated by at least 1 week, in which identical protocols were followed. Subjects completed the following assessments: Visual Clarity, Contrast Sensitivity, Depth Perception, Near-Far Quickness, Target Capture, Perception Span, Eye-Hand Coordination, Go/No Go, and Reaction Time. An additional 36 subjects (20 men, 16 women), age 22 to 35, completed Phase II of the study involving modifications to the equipment, instructions, and protocols from Phase I. Results show no significant change in performance over time on assessments of Visual Clarity, Contrast Sensitivity, Depth Perception, Target Capture, Perception Span, and Reaction Time. Performance did improve over time for Near-Far Quickness, Eye-Hand Coordination, and Go/No Go. The results of this study show that many of the Nike Sensory Station assessments show repeatability and no learning effect over time. The measures that did improve across sessions show an expected learning effect caused by the motor response characteristics being measured. Copyright © 2011 American Optometric Association. Published by Elsevier Inc. All rights reserved.

Presentations of Shape in Object Recognition and Long-Term Visual Memory

DTIC Science & Technology

1994-04-05

theory of human image understanding . Psychological Review, 94, 115-147. Biederman, I., & Gerhardstein, P. C. (1993). Recognizing depth-rotated...Kybemetik. Submitted to Journal of Experimental Psychology: Human Perception and Performance. REFERENCES Biederman, I. (1987). Recognition-by-components: A

Size cues and the adjacency principle.

DOT National Transportation Integrated Search

1963-11-01

The purpose of the present study was to apply the adjacency principle to the perception of relative depth from size cues. In agreement with the adjacency principle, it was found that the size cue between adjacent objects was more effective than the s...

Illusion in reality: visual perception in displays

NASA Astrophysics Data System (ADS)

Kaufman, Lloyd; Kaufman, James H.

2001-06-01

Research into visual perception ultimately affects display design. Advance in display technology affects, in turn, our study of perception. Although this statement is too general to provide controversy, this paper present a real-life example that may prompt display engineers to make greater use of basic knowledge of visual perception, and encourage those who study perception to track more closely leading edge display technology. Our real-life example deals with an ancient problem, the moon illusion: why does the horizon moon appear so large while the elevated moon look so small. This was a puzzle for many centuries. Physical explanations, such as refraction by the atmosphere, are incorrect. The difference in apparent size may be classified as a misperception, so the answer must lie in the general principles of visual perception. The factors underlying the moon illusion must be the same factors as those that enable us to perceive the sizes of ordinary objects in visual space. Progress toward solving the problem has been irregular, since methods for actually measuring the illusion under a wide range of conditions were lacking. An advance in display technology made possible a serious and methodologically controlled study of the illusion. This technology was the first heads-up display. In this paper we will describe how the heads-up display concept made it possible to test several competing theories of the moon illusion, and how it led to an explanation that stood for nearly 40 years. We also consider the criticisms of that explanation and how the optics of the heads-up display also played a role in providing data for the critics. Finally, we will describe our own advance on the original methodology. This advance was motivated by previously unrelated principles of space perception. We used a stereoscopic heads up display to test alternative hypothesis about the illusion and to discrimate between two classes of mutually contradictory theories. At its core, the explanation for the moon illusion has implications for the design of virtual reality displays. Howe do we scale disparity at great distances to reflect depth between points at those distances. We conjecture that one yardstick involved in that scaling is provided by oculomotor cues operating at near distances. Without the presence of such a yardstick it is not possible to account for depth at long distances. As we shall explain, size and depth constancy should both fail in virtual reality display where all of the visual information is optically in one plane. We suggest ways to study this problem, and also means by which displays may be designed to present information at different optical distances.

African American student perception of persistence in engineering at a predominantly white institution

NASA Astrophysics Data System (ADS)

Bennett, Sean T.

This study examines African American student perceptions of persistence in engineering. The research design is methodologically qualitative using a purposefully selected population of engineering students. Semi-structured interviews were designed to develop an in-depth understanding of what completion of the engineering degree means to African American engineering students. This research seeks insight into the linkages between African American student perceptions of persistence as it relates to both the academic and social culture of the engineering department. Vincent Tinto's model of Institutional Departure (1975, 1987) is one of the most commonly cited models of persistence in higher education (Braxton, Milem, Sullivan, 2000). Tinto's model was leveraged in this study to understand perceptions obtained through student interviews. Tinto suggests that exploration of student goal commitment and perceptions of institutional commitment are key to understanding student persistence. Results of this study suggest that African American students have perceptions about the university that may influence the decision to persist in engineering. Ultimately, this study may prove useful to researchers and administrators interested in improving access and success for African American engineering students.

Perception of Child Weight and Feeding Styles in Parents of Chinese-American Preschoolers.

PubMed

Chang, Lucy Y; Mendelsohn, Alan L; Fierman, Arthur H; Au, Loretta Y; Messito, Mary Jo

2017-04-01

Parent perception of weight and feeding styles are associated with obesity in other racial groups but have not been explored in-depth in Chinese-American preschoolers. Cross-sectional survey of 253 Chinese-American parents with preschoolers was performed in a community clinic. Regression analysis was used to assess relationships between parental perception of weight and feeding styles. Parent under-perception of weight was common but more likely in boys than girls (χ 2  = 4.91, p = 0.03). Pressuring was also greater in boys [adjusted mean difference (95% CI) 0.24 (0.004, 0.49)]. In girls, pressuring was lower for children perceived as overweight [adjusted mean difference in CFQ scores -0.75 (-1.27, -0.23)]; in boys, pressuring was high regardless of perceived child weight. Weight perceptions and feeding styles related to childhood obesity in other groups were identified in Chinese-American families. Parent under-perception of child weight and pressure to eat were more common in boys. These factors should be addressed in Chinese-American preschooler obesity prevention programs.

Climate Change Perceptions of NY State Farmers: The Role of Risk Perceptions and Adaptive Capacity.

PubMed

Takahashi, Bruno; Burnham, Morey; Terracina-Hartman, Carol; Sopchak, Amanda R; Selfa, Theresa

2016-12-01

Climate change is expected to severely impact agricultural practices in many important food-producing regions, including the Northeast United States. Changing climate conditions, such as increases in the amount of rainfall, will require farmers to adapt. Yet, little is known with regard to farmers' perceptions and understandings about climate change, especially in the industrialized country context. This paper aims at overcoming this research limitation, as well as determining the existing contextual, cognitive, and psychological barriers that can prevent adoption of sustainable practices of farmers in New York State. The study is framed within the adaptive capacity and risk perception literature, and is based on a qualitative analysis of in-depth interviews with farmers in 21 farms in two counties in Central New York. The results reveal diverging views about the long-term consequences of climate change. Results also reveal that past experience remains as the most important source of information that influences beliefs and perceptions about climate change, confirming previous research.

Climate Change Perceptions of NY State Farmers: The Role of Risk Perceptions and Adaptive Capacity

NASA Astrophysics Data System (ADS)

Takahashi, Bruno; Burnham, Morey; Terracina-Hartman, Carol; Sopchak, Amanda R.; Selfa, Theresa

2016-12-01

Climate change is expected to severely impact agricultural practices in many important food-producing regions, including the Northeast United States. Changing climate conditions, such as increases in the amount of rainfall, will require farmers to adapt. Yet, little is known with regard to farmers' perceptions and understandings about climate change, especially in the industrialized country context. This paper aims at overcoming this research limitation, as well as determining the existing contextual, cognitive, and psychological barriers that can prevent adoption of sustainable practices of farmers in New York State. The study is framed within the adaptive capacity and risk perception literature, and is based on a qualitative analysis of in-depth interviews with farmers in 21 farms in two counties in Central New York. The results reveal diverging views about the long-term consequences of climate change. Results also reveal that past experience remains as the most important source of information that influences beliefs and perceptions about climate change, confirming previous research.

Networking activities and perceptions of HIV risk among male migrant market vendors in China.

PubMed

Wang, Wenqing; Muessig, Kathryn E; Li, Mingqiang; Zhang, Ying-Xia; Zhang, Yingxia

2014-02-01

HIV research among internal migrants in China has not fully explored the contexts and perceptions of "risk". In 2011, urban markets in Liuzhou, China were mapped, and sixty male vendors, age 22-56, were selected for in-depth interviews on migration, social and family life, and perceptions and practices of sexual risk behavior. Participants were evenly divided among higher income shop and small stall vendors. All men were sexually active. Only the shop vendors reported non-marital sexual partners, including concurrent partners (n = 15), commercial partners (n = 10), and other sexual relationships (n = 11). Shop vendors engaged in networking activities that facilitated commercial and non-commercial high-risk sex. Perceptions of HIV risk from commercial sex led some men to doubt the protective ability of condoms and rely on local (unproven) self-protection techniques. Networking activities played a role in high-risk sex and shaping migrants' risk perceptions and health practices. The networks created through these processes could also be used to facilitate health promotion activities.

Evaluation of Patient Perceptions After Vestibuloplasty Procedure: A Comparison of Diode Laser and Scalpel Techniques

PubMed Central

Farista, Sana; Koppolu, Pradeep; Baroudi, Kusai; Uppada, Udaykiran; Mishra, Ashank; Savarimath, Abhishek; Lingam, Amara Swapna

2016-01-01

Introduction Inadequate vestibular depth results in poor plaque control owing to an insufficient width of keratinized gingiva. Vestibuloplasty provides the necessary vestibular depth and can be performed either with a scalpel, electrocautery or lasers. Aim To evaluate the patient perceptions related to pain and discomfort on the 1st, 3rd and the 7th day post vestibuloplasty and also assess the healing outcomes related to the treatment of inadequate vestibular depth either with the diode laser or the scalpel. Materials and Methods Twenty patients who had inadequate vestibular depth and required vestibuloplasty were assigned randomly to undergo the procedure either with the scalpel or the laser. The data obtained was analysed for intergroup comparison with an independent paired t-test and intragroup comparison was determined by a paired t-test. Results Intragroup comparison within the laser group for VAS scores of pain and discomfort within all the reported days exhibited a significant difference (p<0.05). Inter group comparison revealed that the patients in the laser group had lower VAS cores for pain and discomfort compared to the scalpel group (p<0.05). Analysis of the three pointer scale for healing revealed that the patients in the laser group exhibited better healing outcomes on the 1st, 3rd and the 7th day compared to the scalpel group. Conclusion Observations from the study highlight the opinion that laser can be a safe and effective alternative to traditional vestibuloplasty performed with the scalpel. PMID:27437370

The TINS Lecture. The parietal association cortex in depth perception and visual control of hand action.

PubMed

Sakata, H; Taira, M; Kusunoki, M; Murata, A; Tanaka, Y

1997-08-01

Recent neurophysiological studies in alert monkeys have revealed that the parietal association cortex plays a crucial role in depth perception and visually guided hand movement. The following five classes of parietal neurons covering various aspects of these functions have been identified: (1) depth-selective visual-fixation (VF) neurons of the inferior parietal lobule (IPL), representing egocentric distance; (2) depth-movement sensitive (DMS) neurons of V5A and the ventral intraparietal (VIP) area representing direction of linear movement in 3-D space; (3) depth-rotation-sensitive (RS) neurons of V5A and the posterior parietal (PP) area representing direction of rotary movement in space; (4) visually responsive manipulation-related neurons (visual-dominant or visual-and-motor type) of the anterior intraparietal (AIP) area, representing 3-D shape or orientation (or both) of objects for manipulation; and (5) axis-orientation-selective (AOS) and surface-orientation-selective (SOS) neurons in the caudal intraparietal sulcus (cIPS) sensitive to binocular disparity and representing the 3-D orientation of the longitudinal axes and flat surfaces, respectively. Some AOS and SOS neurons are selective in both orientation and shape. Thus the dorsal visual pathway is divided into at least two subsystems, V5A, PP and VIP areas for motion vision and V6, LIP and cIPS areas for coding position and 3-D features. The cIPS sends the signals of 3-D features of objects to the AIP area, which is reciprocally connected to the ventral premotor (F5) area and plays an essential role in matching hand orientation and shaping with 3-D objects for manipulation.

Fiber bundle endomicroscopy with multi-illumination for three-dimensional reflectance image reconstruction

NASA Astrophysics Data System (ADS)

Ando, Yoriko; Sawahata, Hirohito; Kawano, Takeshi; Koida, Kowa; Numano, Rika

2018-02-01

Bundled fiber optics allow in vivo imaging at deep sites in a body. The intrinsic optical contrast detects detailed structures in blood vessels and organs. We developed a bundled-fiber-coupled endomicroscope, enabling stereoscopic three-dimensional (3-D) reflectance imaging with a multipositional illumination scheme. Two illumination sites were attached to obtain reflectance images with left and right illumination. Depth was estimated by the horizontal disparity between the two images under alternative illuminations and was calibrated by the targets with known depths. This depth reconstruction was applied to an animal model to obtain the 3-D structure of blood vessels of the cerebral cortex (Cereb cortex) and preputial gland (Pre gla). The 3-D endomicroscope could be instrumental to microlevel reflectance imaging, improving the precision in subjective depth perception, spatial orientation, and identification of anatomical structures.

Learning Experiences of University Biology Faculty: A Qualitative Pilot Study

ERIC Educational Resources Information Center

Kusch, Jennifer

2016-01-01

The study described in this article incorporates qualitative research through in-depth, individual, structured interviews with 12 biology faculty from two Midwestern universities to explore perceptions about how they have learned to teach and how they work to improve their skills.

Problems in depth perception : equidistance judgments in the vicinity of a binocular illusion.

DOT National Transportation Integrated Search

1966-07-01

Judgments of the size and distance of objects are sometimes made in aircraft under background-viewing conditions that may themselves create false sensory impressions (illusions). In this study, the effects of a background illusion on judgments of the...

The equidistance tendency and its consequences : problems in depth perception.

DOT National Transportation Integrated Search

1965-04-01

The equidistance tendency is the tendency for objects or other inhomogeneities in the field-of-view to appear at the same distance as each other with the strength of this tendency being inversely related to directional separation. The evidence for th...

Correction techniques for depth errors with stereo three-dimensional graphic displays

NASA Technical Reports Server (NTRS)

Parrish, Russell V.; Holden, Anthony; Williams, Steven P.

1992-01-01

Three-dimensional (3-D), 'real-world' pictorial displays that incorporate 'true' depth cues via stereopsis techniques have proved effective for displaying complex information in a natural way to enhance situational awareness and to improve pilot/vehicle performance. In such displays, the display designer must map the depths in the real world to the depths available with the stereo display system. However, empirical data have shown that the human subject does not perceive the information at exactly the depth at which it is mathematically placed. Head movements can also seriously distort the depth information that is embedded in stereo 3-D displays because the transformations used in mapping the visual scene to the depth-viewing volume (DVV) depend intrinsically on the viewer location. The goal of this research was to provide two correction techniques; the first technique corrects the original visual scene to the DVV mapping based on human perception errors, and the second (which is based on head-positioning sensor input data) corrects for errors induced by head movements. Empirical data are presented to validate both correction techniques. A combination of the two correction techniques effectively eliminates the distortions of depth information embedded in stereo 3-D displays.

Relationship between perception of image resolution and peripheral visual field in stereoscopic images

NASA Astrophysics Data System (ADS)

Ogawa, Masahiko; Shidoji, Kazunori

2011-03-01

High-resolution stereoscopic images are effective for use in virtual reality and teleoperation systems. However, the higher the image resolution, the higher is the cost of computer processing and communication. To reduce this cost, numerous earlier studies have suggested the use of multi-resolution images, which have high resolution in region of interests and low resolution in other areas. However, observers can perceive unpleasant sensations and incorrect depth because they can see low-resolution areas in their field of vision. In this study, we conducted an experiment to research the relationship between the viewing field and the perception of image resolution, and determined respective thresholds of image-resolution perception for various positions of the viewing field. The results showed that participants could not distinguish between the high-resolution stimulus and the decreased stimulus, 63 ppi, at positions more than 8 deg outside the gaze point. Moreover, with positions shifted a further 11 and 13 deg from the gaze point, participants could not distinguish between the high-resolution stimulus and the decreased stimuli whose resolution densities were 42 and 25 ppi. Hence, we will propose the composition of multi-resolution images in which observers do not perceive unpleasant sensations and incorrect depth with data reduction (compression).

Effects of rhythmic stimulus presentation on oscillatory brain activity: the physiology of cueing in Parkinson’s disease

PubMed Central

te Woerd, Erik S.; Oostenveld, Robert; Bloem, Bastiaan R.; de Lange, Floris P.; Praamstra, Peter

2015-01-01

The basal ganglia play an important role in beat perception and patients with Parkinson’s disease (PD) are impaired in perception of beat-based rhythms. Rhythmic cues are nonetheless beneficial in gait rehabilitation, raising the question how rhythm improves movement in PD. We addressed this question with magnetoencephalography recordings during a choice response task with rhythmic and non-rhythmic modes of stimulus presentation. Analyses focused on (i) entrainment of slow oscillations, (ii) the depth of beta power modulation, and (iii) whether a gain in modulation depth of beta power, due to rhythmicity, is of predictive or reactive nature. The results show weaker phase synchronisation of slow oscillations and a relative shift from predictive to reactive movement-related beta suppression in PD. Nonetheless, rhythmic stimulus presentation increased beta modulation depth to the same extent in patients and controls. Critically, this gain selectively increased the predictive and not reactive movement-related beta power suppression. Operation of a predictive mechanism, induced by rhythmic stimulation, was corroborated by a sensory gating effect in the sensorimotor cortex. The predictive mode of cue utilisation points to facilitation of basal ganglia-premotor interactions, contrasting with the popular view that rhythmic stimulation confers a special advantage in PD, based on recruitment of alternative pathways. PMID:26509117

Description of Success: A Four-Teacher Instructional Model.

ERIC Educational Resources Information Center

Reed, Dianne

This study described a four-teacher instructional model in operation at an elementary school, noting the perceptions of fourth grade students, parents, and teachers regarding the model. The model encompassed teaming, block scheduling, departmentalization of subjects, integrated/interdisciplinary instruction, and in-depth instruction in each…

PSYCHOSOCIAL PHENOMENA AND BUILDING DESIGN.

ERIC Educational Resources Information Center

IZUMI, KIYOSHI

THE DEPTH OF PSYCHOSOCIAL CONSIDERATION VARIES WITH ARCHITECTURAL FUNCTION. THESE FACTORS INCREASE AS A BUILDING USAGE BECOMES MORE ANTHROPOPHILIC. SITUATIONS RELATING TO AMBIGUOUS DESIGN MUST BE ELIMINATED IN BUILDING DESIGN. PROBLEMS INVOLVING VISUAL PERCEPTION SUCH AS (1) GLASS DOORS, (2) APPARENT INSECURITY OF STRUCTURE, (3) AMBIGUOUS SYMBOLIC…

Parent Empowerment and Teacher Professionalism: Teachers' Perspective

ERIC Educational Resources Information Center

Addi-Raccah, Audrey; Arviv-Elyashiv, Rinate

2008-01-01

School decentralization, which has reshaped power relations in the educational system, has empowered teachers and parents. Taking Abbott's approach to professions, the authors examine teachers' perceptions of the implications of parents' empowerment for teacher--parent relations. In-depth interviews with homeroom teachers in affluent urban…

Visual risk factors for falls in older people.

PubMed

Lord, Stephen R

2006-09-01

Poor vision reduces postural stability and significantly increases the risk of falls and fractures in older people. Most studies have found that poor visual acuity increases the risk of falls. However, studies that have included multiple visual measures have found that reduced contrast sensitivity and depth perception are the most important visual risk factors for falls. Multifocal glasses may add to this risk because their near-vision lenses impair distance contrast sensitivity and depth perception in the lower visual field. This reduces the ability of an older person to detect environmental hazards. There is now evidence that maximising vision through cataract surgery is an effective strategy for preventing falls. Further randomised controlled trials are required to determine whether individual strategies (such as restriction of use of multifocal glasses) or multi-strategy visual improvement interventions can significantly reduce falls in older people. Public health initiatives are required to raise awareness in older people and their carers of the importance of regular eye examinations and use of appropriate prescription glasses.

Binocular Perception of 2D Lateral Motion and Guidance of Coordinated Motor Behavior.

PubMed

Fath, Aaron J; Snapp-Childs, Winona; Kountouriotis, Georgios K; Bingham, Geoffrey P

2016-04-01

Zannoli, Cass, Alais, and Mamassian (2012) found greater audiovisual lag between a tone and disparity-defined stimuli moving laterally (90-170 ms) than for disparity-defined stimuli moving in depth or luminance-defined stimuli moving laterally or in depth (50-60 ms). We tested if this increased lag presents an impediment to visually guided coordination with laterally moving objects. Participants used a joystick to move a virtual object in several constant relative phases with a laterally oscillating stimulus. Both the participant-controlled object and the target object were presented using a disparity-defined display that yielded information through changes in disparity over time (CDOT) or using a luminance-defined display that additionally provided information through monocular motion and interocular velocity differences (IOVD). Performance was comparable for both disparity-defined and luminance-defined displays in all relative phases. This suggests that, despite lag, perception of lateral motion through CDOT is generally sufficient to guide coordinated motor behavior.

The specificity of cortical region KO to depth structure.

PubMed

Tyler, Christopher W; Likova, Lora T; Kontsevich, Leonid L; Wade, Alex R

2006-03-01

Functional MRI studies have identified a cortical region designated as KO between retinotopic areas V3A/B and motion area V5 in human cortex as particularly responsive to motion-defined or kinetic borders. To determine the response of the KO region to more general aspects of structure, we used stereoscopic depth borders and disparate planes with no borders, together with three stimulus types that evoked no depth percept: luminance borders, line contours and illusory phase borders. Responses to these stimuli in the KO region were compared with the responses in retinotopically defined areas that have been variously associated with disparity processing in neurophysiological and fMRI studies. The strongest responses in the KO region were to stimuli evoking perceived depth structure from either disparity or motion cues, but it showed negligible responses either to luminance-based contour stimuli or to edgeless disparity stimuli. We conclude that the region designated as KO is best regarded as a primary center for the generic representation of depth structure rather than any kind of contour specificity.

The perception of three-dimensionality across continuous surfaces

NASA Technical Reports Server (NTRS)

Stevens, Kent A.

1989-01-01

The apparent three-dimensionality of a viewed surface presumably corresponds to several internal preceptual quantities, such as surface curvature, local surface orientation, and depth. These quantities are mathematically related for points within the silhouette bounds of a smooth, continuous surface. For instance, surface curvature is related to the rate of change of local surface orientation, and surface orientation is related to the local gradient of distance. It is not clear to what extent these 3D quantities are determined directly from image information rather than indirectly from mathematically related forms, by differentiation or by integration within boundary constraints. An open empirical question, for example, is to what extent surface curvature is perceived directly, and to what extent it is quantitative rather than qualitative. In addition to surface orientation and curvature, one derives an impression of depth, i.e., variations in apparent egocentric distance. A static orthographic image is essentially devoid of depth information, and any quantitative depth impression must be inferred from surface orientation and other sources. Such conversion of orientation to depth does appear to occur, and even to prevail over stereoscopic depth information under some circumstances.

Differential responses in dorsal visual cortex to motion and disparity depth cues

PubMed Central

Arnoldussen, David M.; Goossens, Jeroen; van den Berg, Albert V.

2013-01-01

We investigated how interactions between monocular motion parallax and binocular cues to depth vary in human motion areas for wide-field visual motion stimuli (110 × 100°). We used fMRI with an extensive 2 × 3 × 2 factorial blocked design in which we combined two types of self-motion (translational motion and translational + rotational motion), with three categories of motion inflicted by the degree of noise (self-motion, distorted self-motion, and multiple object-motion), and two different view modes of the flow patterns (stereo and synoptic viewing). Interactions between disparity and motion category revealed distinct contributions to self- and object-motion processing in 3D. For cortical areas V6 and CSv, but not the anterior part of MT+ with bilateral visual responsiveness (MT+/b), we found a disparity-dependent effect of rotational flow and noise: When self-motion perception was degraded by adding rotational flow and moderate levels of noise, the BOLD responses were reduced compared with translational self-motion alone, but this reduction was cancelled by adding stereo information which also rescued the subject's self-motion percept. At high noise levels, when the self-motion percept gave way to a swarm of moving objects, the BOLD signal strongly increased compared to self-motion in areas MT+/b and V6, but only for stereo in the latter. BOLD response did not increase for either view mode in CSv. These different response patterns indicate different contributions of areas V6, MT+/b, and CSv to the processing of self-motion perception and the processing of multiple independent motions. PMID:24339808

Perceived change in orientation from optic flow in the central visual field

NASA Technical Reports Server (NTRS)

Dyre, Brian P.; Andersen, George J.

1988-01-01

The effects of internal depth within a simulation display on perceived changes in orientation have been studied. Subjects monocularly viewed displays simulating observer motion within a volume of randomly positioned points through a window which limited the field of view to 15 deg. Changes in perceived spatial orientation were measured by changes in posture. The extent of internal depth within the display, the presence or absence of visual information specifying change in orientation, and the frequency of motion supplied by the display were examined. It was found that increased sway occurred at frequencies equal to or below 0.375 Hz when motion at these frequencies was displayed. The extent of internal depth had no effect on the perception of changing orientation.

Measuring sensitivity to viewpoint change with and without stereoscopic cues.

PubMed

Bell, Jason; Dickinson, Edwin; Badcock, David R; Kingdom, Frederick A A

2013-12-04

The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this transformation. Here we discuss a novel method for simulating the appearance of an object that has undergone a rotation-in-depth, and include an exposition of the differences between perspective and orthographic projections. Next we describe a method by which human sensitivity to rotation-in-depth can be measured. Finally we discuss an apparatus for creating a vivid percept of a 3-dimensional rotation-in-depth; the Wheatstone Eight Mirror Stereoscope. By doing so, we reveal a means by which to evaluate the role of stereoscopic cues in the discrimination of viewpoint rotated shapes and objects.

Stereoscopic depth increases intersubject correlations of brain networks.

PubMed

Gaebler, Michael; Biessmann, Felix; Lamke, Jan-Peter; Müller, Klaus-Robert; Walter, Henrik; Hetzer, Stefan

2014-10-15

Three-dimensional movies presented via stereoscopic displays have become more popular in recent years aiming at a more engaging viewing experience. However, neurocognitive processes associated with the perception of stereoscopic depth in complex and dynamic visual stimuli remain understudied. Here, we investigate the influence of stereoscopic depth on both neurophysiology and subjective experience. Using multivariate statistical learning methods, we compare the brain activity of subjects when freely watching the same movies in 2D and in 3D. Subjective reports indicate that 3D movies are more strongly experienced than 2D movies. On the neural level, we observe significantly higher intersubject correlations of cortical networks when subjects are watching 3D movies relative to the same movies in 2D. We demonstrate that increases in intersubject correlations of brain networks can serve as neurophysiological marker for stereoscopic depth and for the strength of the viewing experience. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Ethical Becoming: Adult Ethical Development in Christian Congregations

ERIC Educational Resources Information Center

Carr-Chellman, Davin J.

2011-01-01

This is a study of adult ethical development in Christian congregations. Using an empirical hermeneutic phenomenological methodology, this study examined how five pastors understand and encourage ethical development, developing an in-depth analysis and interpretation of their perceptions of the phenomenon of adult ethical development. Two primary…

Professional Development Models That Promote Teacher Change and Impact Student Achievement

ERIC Educational Resources Information Center

Hawkins, Dawn

2017-01-01

To capture participants' perspectives regarding their experiences in South Carolina's Upstate Writing Project professional development, a series of in-depth, qualitative interviews was conducted with four teachers and two curriculum coaches from participating districts. Data provided insight into participant's perceptions of how their experiences…

Elementary School Counselors' Collaboration with Community Mental Health Providers

ERIC Educational Resources Information Center

Moran, Kristen; Bodenhorn, Nancy

2015-01-01

Perceptions and experiences of elementary school counselors' collaborative efforts with community mental health providers are examined through this exploratory phenomenological study. Ten participants engaged in two in-depth interviews. Collaboration was considered an effective way to increase services to students and their families. Six themes…

Students' Perspectives on Gatekeeping in Counselor Education: A Case Study

ERIC Educational Resources Information Center

Foster, Jennifer M.; Leppma, Monica; Hutchinson, Tracy S.

2014-01-01

Through in-depth interviews, the authors examined 10 master's-level counseling students' perceptions of gatekeeping. Case analysis resulted in 3 major themes pertaining to the necessity of gatekeeping, vital components, and counseling student characteristics. Implications of the findings are also discussed.

Developing Leadership: Exploring Childhoods of Women University Presidents

ERIC Educational Resources Information Center

Madsen, Susan R.

2007-01-01

Purpose: Researchers argue that much of who we are is developed during childhood. Yet, little exploratory research has been conducted regarding the childhood experiences, activities, personalities, and perceptions of successful leaders. This paper aims to address this issue. Design/methodology/approach: In-depth, qualitative interviews were…

Color constrains depth in da Vinci stereopsis for camouflage but not occlusion.

PubMed

Wardle, Susan G; Gillam, Barbara J

2013-12-01

Monocular regions that occur with binocular viewing of natural scenes can produce a strong perception of depth--"da Vinci stereopsis." They occur either when part of the background is occluded in one eye, or when a nearer object is camouflaged against a background surface in one eye's view. There has been some controversy over whether da Vinci depth is constrained by geometric or ecological factors. Here we show that the color of the monocular region constrains the depth perceived from camouflage, but not occlusion, as predicted by ecological considerations. Quantitative depth was found in both cases, but for camouflage only when the color of the monocular region matched the binocular background. Unlike previous reports, depth failed even when nonmatching colors satisfied conditions for perceptual transparency. We show that placing a colored line at the boundary between the binocular and monocular regions is sufficient to eliminate depth from camouflage. When both the background and the monocular region contained vertical contours that could be fused, some observers appeared to use fusion, and others da Vinci constraints, supporting the existence of a separate da Vinci mechanism. The results show that da Vinci stereopsis incorporates color constraints and is more complex than previously assumed.

Method and simulation to study 3D crosstalk perception

NASA Astrophysics Data System (ADS)

Khaustova, Dar'ya; Blondé, Laurent; Huynh-Thu, Quan; Vienne, Cyril; Doyen, Didier

2012-03-01

To various degrees, all modern 3DTV displays suffer from crosstalk, which can lead to a decrease of both visual quality and visual comfort, and also affect perception of depth. In the absence of a perfect 3D display technology, crosstalk has to be taken into account when studying perception of 3D stereoscopic content. In order to improve 3D presentation systems and understand how to efficiently eliminate crosstalk, it is necessary to understand its impact on human perception. In this paper, we present a practical method to study the perception of crosstalk. The approach consists of four steps: (1) physical measurements of a 3DTV, (2) building of a crosstalk surface based on those measurements and representing specifically the behavior of that 3TV, (3) manipulation of the crosstalk function and application on reference images to produce test images degraded by crosstalk in various ways, and (4) psychophysical tests. Our approach allows both a realistic representation of the behavior of a 3DTV and the easy manipulation of its resulting crosstalk in order to conduct psycho-visual experiments. Our approach can be used in all studies requiring the understanding of how crosstalk affects perception of stereoscopic content and how it can be corrected efficiently.

Perceptions of Healthy Eating in Four Alberta Communities: A Photovoice Project

PubMed Central

Hammer, Brent A.; Vallianatos, Helen; Nieuwendyk, Laura M.

2016-01-01

Peoples’ perceptions of healthy eating are influenced by the cultural context in which they occur. Despite this general acceptance by health practitioners and social scientists, studies suggest that there remains a relative homogeneity around peoples’ perceptions that informs a hegemonic discourse around healthy eating. People often describe healthy eating in terms of learned information from sources that reflect societies’ norms and values, such as the Canada Food Guide and the ubiquitous phrase “fruits and vegetables”. Past research has examined how built environments shape people’s access to healthy living options, such as distribution of grocers versus convenience stores and fast food restaurants. Often overlooked is an in-depth understanding of how social contexts interact with built environments, molding peoples’ perceptions of healthy eating. This paper reports on perceptions of healthy eating in four communities across Alberta, Canada. A photovoice methodology was employed to elicit perceptions of healthy eating with 35 participants. This study illustrates how participants’ photographs and their stories convey multiple meanings about healthy eating within their own lives and communities. Findings suggest that a ‘local’ context is an important part of the discourse centered around the promotion of healthy eating practices in these and potential other communities. PMID:27390390

Perceptions of Healthy Eating in Four Alberta Communities: A Photovoice Project.

PubMed

Hammer, Brent A; Vallianatos, Helen; Nykiforuk, Candace; Nieuwendyk, Laura M

2015-01-23

Peoples' perceptions of healthy eating are influenced by the cultural context in which they occur. Despite this general acceptance by health practitioners and social scientists, studies suggest that there remains a relative homogeneity around peoples' perceptions that informs a hegemonic discourse around healthy eating. People often describe healthy eating in terms of learned information from sources that reflect societies' norms and values, such as the Canada Food Guide and the ubiquitous phrase "fruits and vegetables". Past research has examined how built environments shape people's access to healthy living options, such as distribution of grocers versus convenience stores and fast food restaurants. Often overlooked is an in-depth understanding of how social contexts interact with built environments, molding peoples' perceptions of healthy eating. This paper reports on perceptions of healthy eating in four communities across Alberta, Canada. A photovoice methodology was employed to elicit perceptions of healthy eating with 35 participants. This study illustrates how participants' photographs and their stories convey multiple meanings about healthy eating within their own lives and communities. Findings suggest that a 'local' context is an important part of the discourse centered around the promotion of healthy eating practices in these and potential other communities.

Risk perception and moralization among smokers in the USA and Denmark: a qualitative approach.

PubMed

Helweg-Larsen, Marie; Tobias, Margaret R; Cerban, Bettina M

2010-11-01

The present research explored the role that culture plays in smokers' description of their risk perceptions and experiences as targets of moralization. We conducted in-depth qualitative interviews with 15 smokers each from Denmark (a smoking-lenient culture) and the USA (a smoking-prohibitive culture). Smokers said they were well aware of the risks of smoking yet minimized the risks of active and passive smoking; Danes were particularly likely to minimize these risks. Smokers also described many experiences as targets of moralization and accepted some elements of moralized attitudes although overall Danes more strongly rejected moralized opinions. Smokers described adjusting to moralization by changing when and where but not how much they smoked. It is important to consider cultural influences on moralization and risk perception of smoking.

Responses of dairy heifers to the visual cliff formed by a herringbone milking pit: evidence of fear of heights in cows (Bos taurus).

PubMed

Arnold, Naomi Adele; Ng, Kim Tee; Jongman, Ellen Caroline; Hemsworth, Paul Hamilton

2007-11-01

The ability of cows (Bos taurus) to perceive depth has never been experimentally investigated. If cows can perceive depth, the milking pit in commercial milking facilities may be fear provoking for dairy cows, as past research has shown that most land-dwelling species possess an instinctive fear of heights. In the current study, 12 dairy heifers (1-year-old cows) were exposed to a milking pit (depth-exposed group) and 13 heifers (control group) were exposed to a standard change in the environment while they moved through a milking facility over a 5-day treatment period. Heifers in the depth-exposed group showed a higher heart rate (p < .05) and stopped more often (p < .05) than did those in the control group; persistence of heart rate but not of behavioral responses on repeated exposures indicated that some habituation to the depth stimulus had occurred. Depth exposure had no effect on cortisol concentrations or on ease of handling. These results indicate that heifers responded differently to a change in depth than they did to a standard change in the environment and provide evidence of both depth perception and acute fear of heights in cows. Copyright 2007 APA.

Networking Activities and Perceptions of HIV Risk Among Male Migrant Market Vendors in China

PubMed Central

Wang, Wenqing; Muessig, Kathryn E.; Li, Mingqiang; Zhang, Yingxia

2013-01-01

HIV research among internal migrants in China has not fully explored the contexts and perceptions of “risk”. In 2011, urban markets in Liuzhou, China were mapped, and sixty male vendors, age 22 to 56, were selected for in-depth interviews on migration, social and family life, and perceptions and practices of sexual risk behavior. Participants were evenly divided among higher income shop and small stall vendors. All men were sexually active. Only the shop vendors reported non-marital sexual partners, including concurrent partners (n=15), commercial partners (n=10), and other sexual relationships (n=11). Shop vendors engaged in networking activities that facilitated commercial and non-commercial high-risk sex. Perceptions of HIV risk from commercial sex led some men to doubt the protective ability of condoms and rely on local (unproven) self-protection techniques. Networking activities played a role in high-risk sex and shaping migrants' risk perceptions and health practices. The networks created through these processes could also be used to facilitate health promotion activities. PMID:23572155

Disadvantaged Former Miners' Perspectives on Smoking Cessation: A Qualitative Study

ERIC Educational Resources Information Center

White, Simon; Baird, Wendy

2013-01-01

Objective: To explore disadvantaged former miners' perspectives in north Derbyshire, United Kingdom (UK) on smoking and smoking cessation. Methods: In-depth, audiotaped interviews with 16 disadvantaged former miners who smoked or had stopped smoking within six months. Results: Perceptions of being able to stop smoking with minimal difficulty and…

Gendered Harassment in Secondary Schools: Understanding Teachers' (Non) Interventions

ERIC Educational Resources Information Center

Meyer, Elizabeth J.

2008-01-01

This article provides an analysis of teachers' perceptions of and responses to gendered harassment in Canadian secondary schools based on in-depth interviews with six teachers in one urban school district. Gendered harassment includes any behaviour that polices and reinforces traditional heterosexual gender norms such as (hetero)sexual harassment,…

Communicating with homeowners in the interface about defensible space

Treesearch

Martha C. Monroe; Michelle Payton

2006-01-01

Although resource managers encourage residents to create defensible space, many report that homeowners still live in risky landscapes. This study explores the perceptions and attitudes of Minnesota and Florida interface homeowners toward their local landscape. By using in-depth interviews, we gained a better understanding of landscape values, preferences, and...

Contour Entropy: A New Determinant of Perceiving Ground or a Hole

ERIC Educational Resources Information Center

Gillam, Barbara J.; Grove, Philip M.

2011-01-01

Figure-ground perception is typically described as seeing one surface occluding another. Figure properties, not ground properties, are considered the significant factors. In scenes, however, a near surface will often occlude multiple contours and surfaces, often at different depths, producing alignments that are improbable except under conditions…

Elite Cricket Coach Education: A Bourdieusian Analysis

ERIC Educational Resources Information Center

Townsend, Robert C.; Cushion, Christopher

2017-01-01

The social structures within coach education have been largely unexplored, undiscussed, and treated as unproblematic in contributing to coach learning, both in research and practice. The study used semi-structured, in-depth interviews with 11 elite cricket coaches to gather their perceptions of an elite coach education programme. In particular,…

Teacher Practices: How They Promote or Hinder Student Engagement in Mathematics

ERIC Educational Resources Information Center

Skilling, Karen

2014-01-01

With persistent concerns about student engagement, interest and participation in mathematics, this research investigated the range of practices 31 Year 7 mathematics teachers reported using and how they perceived these practices influenced student engagement in mathematics. In-depth interviews revealed similarities in teachers' perceptions of…

Financial Conditions: An In-Depth Look at Fiscal Troubles on Campus.

ERIC Educational Resources Information Center

Scoby, Jerry L.

1993-01-01

A survey of 300 college and university business officers investigated the extent of the institutions' financial difficulties. Results reveal administrators' perceptions of the reasons for and solutions to financial problems, factors in institutional stability or strength, plans to maintain or strengthen the institution's financial condition,…

The International Student's Experience: An Exploratory Study of Students from Vietnam

ERIC Educational Resources Information Center

Wearring, Andrew; Le, Huong; Wilson, Rachel; Arambewela, Rodney

2015-01-01

International students are an important part of today's global university sector. This paper explores, through 10 in-depth interviews, the perceptions of Vietnamese international students studying with regard to their experience of teaching and learning in Australia. The findings indicate that Vietnamese students struggle with language,…

What's Good about Being Gay? Perspectives from Youth

ERIC Educational Resources Information Center

Harper, Gary W.; Brodsky, Asya; Bruce, Douglas

2012-01-01

This article explores gay and bisexual male adolescents' positive perceptions of their sexual orientation identity. In-depth qualitative interviews were conducted with an ethnically diverse sample of 63 gay/bisexual male adolescents in Chicago (N = 42) and Miami (N = 21). Data revealed two major conceptual categories: (1) positive personal…

School Technology Leadership in a Spanish Secondary School: The TEI Model

ERIC Educational Resources Information Center

Gallego-Arrufat, María-Jesús; Gutiérrez-Santiuste, Elba; Campaña-Jiménez, Rafael Luis

2017-01-01

This study analyzes the perception that teachers and management team members in secondary school education have of "technology-based educational innovation" (TEI). Two questionnaires and in-depth interviews permit us to analyze leaders' perspective of planning, development, and evaluation. The school leaders' view diverges from that of…

Social Validity: Perceptions of Check and Connect with Early Literacy Support

ERIC Educational Resources Information Center

Miltich Lyst, Aimee; Gabriel, Stacey; O'Shaughnessy, Tam E.; Meyers, Joel; Meyers, Barbara

2005-01-01

This article underscores the potential advantages of qualitative methods to illustrate the depth and complexity of social validity. This investigation evaluates the social validity of Check and Connect with Early Literacy Support (CCEL), through the perspectives of teachers and caregivers whose children participated in the intervention. Teachers…

Sensory Sensitivities and Discriminations and their Roles in Aviation

DTIC Science & Technology

1991-10-31

asymmetry. Neurology, in press. 5. Zihl JD, Von Cramon D & Mai N (1983) Selective disturbance of movement vision after bilateral brain damage. Brain...1970) Electrophysiological correlate of binocular depth perception in man. Nature 255, 92-4. 1971 16. Regan D & Sperling HG (1971) A method of evoking

Graduates' Work: Organisational Change and Students' Attributes.

ERIC Educational Resources Information Center

Harvey, Lee; Moon, Sue; Geall, Vicki; Bower, Ray

Employer and employee perceptions of the skills and abilities needed by college graduates in a changing workplace were examined through semistructured, in-depth interviews with a sample of 84 strategic managers, 84 college graduates, and 35 nongraduate employees in 91 organizations across England and Scotland that represented a mix of organization…

Professionalism: Doing a Good Job!

ERIC Educational Resources Information Center

Feather, Denis

2014-01-01

This paper considers the concept of professionalism via perceptions (real or imagined) of lecturers delivering higher education business programmes (HEBPs) in further education colleges in England. The study comprised 26 in-depth interviews conducted in the Yorkshire and Humber region in the UK. The study builds on Perkin's views of a professional…

Using an Artificial Rock Outcrop to Teach Geology

ERIC Educational Resources Information Center

Totten, Iris

2005-01-01

Teaching Earth science without exposure to rock outcrops limits students depth of understanding of Earth's processes, limits the concept of scale from their spatial visualization imaging, and distorts their perception of geologic time (Totten 2003). Through a grant funded by the National Science Foundation, an artificial rock outcrop was…

Women and the Superintendency: Perceptions of Gender Bias

ERIC Educational Resources Information Center

Garn, Gregg; Brown, Casey

2008-01-01

This research explored how 15 female superintendents from a southwestern state experienced issues of gender bias. Participants came from a mix of urban, rural, and suburban districts that varied in size from 150 to 25,000 students. Using in-depth interviews and a transcendental phenomenological qualitative approach, the researchers examined how…

Exploring Young Adult Sexual Minority Women's Perspectives on LGBTQ Smoking

ERIC Educational Resources Information Center

Youatt, Emily J.; Johns, Michelle M.; Pingel, Emily S.; Soler, Jorge H.; Bauermeister, José A.

2015-01-01

Smoking rates are higher among lesbian, gay, bisexual, transgender, and queer (LGBTQ) individuals than among heterosexuals. These disparities are exacerbated during the transition from youth to young adulthood. The current study uses in-depth qualitative interviews to understand perceptions of LGBTQ smoking among LBQ-identified women (N = 30, ages…

Literature for Children: Avoiding Controversy and Intellectual Challenge.

ERIC Educational Resources Information Center

Adams, Dennis M.

1986-01-01

Discusses lack of literature on controversial subjects that can help prepare children and young adults to deal perceptively with complexities of modern world. Highlights include meeting the issues head-on, glorifying armed conflict in video media, avoiding issues of nuclear war, and intellectual depth and dealing with controversial issues. (12…

Teacher Perceptions of Principals' Leadership Qualities: A Mixed Methods Study

ERIC Educational Resources Information Center

Hauserman, Cal P.; Ivankova, Nataliya V.; Stick, Sheldon L.

2013-01-01

This mixed methods sequential explanatory study utilized the Multi-factor Leadership Questionnaire, responses to open-ended questions, and in-depth interviews to identify transformational leadership qualities that were present among principals in Alberta, Canada. The first quantitative phase consisted of a random sample of 135 schools (with…

African American Girls' Ideal Dating Relationship Now and in the Future

ERIC Educational Resources Information Center

Debnam, Katrina J.; Howard, Donna E.; Garza, Mary A.; Green, Kerry M.

2017-01-01

Adolescence is a particularly important and challenging time for developing long-lasting romantic relationship patterns. However, limited empirical research has explored teen perceptions of ideal partner characteristics during adolescence or their significance to the quality of current and future relationships. Semi-structured in-depth interviews…

The Concept of Collection from the User's Perspective

ERIC Educational Resources Information Center

Lee, Hur-Li

2005-01-01

This study explores the concept and functions of collection from the perspective of the user. In-depth interviews with ten professors from a social science discipline and a natural science department provided descriptions of their information seeking involving material sources and their perceptions of the library collection. Participants used the…

Invisible Cultural Barriers: Contrasting Perspectives on Student Veterans' Transition

ERIC Educational Resources Information Center

Lim, Jae Hoon; Interiano, Claudia G.; Nowell, Caroline E.; Tkacik, Peter T.; Dahlberg, Jerry L.

2018-01-01

In this interpretative phenomenological study, the implicit cultural values and expectations embedded in faculty/staff's perceptions and how they functioned as a hidden curriculum against student veterans' smooth transition into higher education were analyzed based on in-depth interviews with 20 student veterans and 9 faculty/staff members. By…

16 CFR 1500.41 - Method of testing primary irritant substances.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) to slight eschar formations (injuries in depth) 4 Edema formation: No edema 0 Very slight edema (barely perceptible) 1 Slight edema (edges of area well defined by definite raising) 2 Moderate edema (raised approximately 1 millimeter) 3 Severe edema (raised more than 1 millimeter and extending beyond the...

16 CFR 1500.41 - Method of testing primary irritant substances.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) to slight eschar formations (injuries in depth) 4 Edema formation: No edema 0 Very slight edema (barely perceptible) 1 Slight edema (edges of area well defined by definite raising) 2 Moderate edema (raised approximately 1 millimeter) 3 Severe edema (raised more than 1 millimeter and extending beyond the...

Employees' Perceptions of Barriers to Participation in Training and Development in Small Engineering Businesses

ERIC Educational Resources Information Center

Susomrith, Pattanee; Coetzer, Alan

2015-01-01

Purpose: This paper aims to investigate barriers to employee participation in voluntary formal training and development opportunities from the perspective of employees in small engineering businesses. Design/methodology/approach: An exploratory qualitative methodology involving data collection via site visits and in-depth semi-structured…

High resolution depth reconstruction from monocular images and sparse point clouds using deep convolutional neural network

NASA Astrophysics Data System (ADS)

Dimitrievski, Martin; Goossens, Bart; Veelaert, Peter; Philips, Wilfried

2017-09-01

Understanding the 3D structure of the environment is advantageous for many tasks in the field of robotics and autonomous vehicles. From the robot's point of view, 3D perception is often formulated as a depth image reconstruction problem. In the literature, dense depth images are often recovered deterministically from stereo image disparities. Other systems use an expensive LiDAR sensor to produce accurate, but semi-sparse depth images. With the advent of deep learning there have also been attempts to estimate depth by only using monocular images. In this paper we combine the best of the two worlds, focusing on a combination of monocular images and low cost LiDAR point clouds. We explore the idea that very sparse depth information accurately captures the global scene structure while variations in image patches can be used to reconstruct local depth to a high resolution. The main contribution of this paper is a supervised learning depth reconstruction system based on a deep convolutional neural network. The network is trained on RGB image patches reinforced with sparse depth information and the output is a depth estimate for each pixel. Using image and point cloud data from the KITTI vision dataset we are able to learn a correspondence between local RGB information and local depth, while at the same time preserving the global scene structure. Our results are evaluated on sequences from the KITTI dataset and our own recordings using a low cost camera and LiDAR setup.

Early vision and focal attention

NASA Astrophysics Data System (ADS)

Julesz, Bela

1991-07-01

At the thirty-year anniversary of the introduction of the technique of computer-generated random-dot stereograms and random-dot cinematograms into psychology, the impact of the technique on brain research and on the study of artificial intelligence is reviewed. The main finding-that stereoscopic depth perception (stereopsis), motion perception, and preattentive texture discrimination are basically bottom-up processes, which occur without the help of the top-down processes of cognition and semantic memory-greatly simplifies the study of these processes of early vision and permits the linking of human perception with monkey neurophysiology. Particularly interesting are the unexpected findings that stereopsis (assumed to be local) is a global process, while texture discrimination (assumed to be a global process, governed by statistics) is local, based on some conspicuous local features (textons). It is shown that the top-down process of "shape (depth) from shading" does not affect stereopsis, and some of the models of machine vision are evaluated. The asymmetry effect of human texture discrimination is discussed, together with recent nonlinear spatial filter models and a novel extension of the texton theory that can cope with the asymmetry problem. This didactic review attempts to introduce the physicist to the field of psychobiology and its problems-including metascientific problems of brain research, problems of scientific creativity, the state of artificial intelligence research (including connectionist neural networks) aimed at modeling brain activity, and the fundamental role of focal attention in mental events.

False Color Terrain Model of Phoenix Workspace

NASA Technical Reports Server (NTRS)

2008-01-01

This is a terrain model of Phoenix's Robotic Arm workspace. It has been color coded by depth with a lander model for context. The model has been derived using images from the depth perception feature from Phoenix's Surface Stereo Imager (SSI). Red indicates low-lying areas that appear to be troughs. Blue indicates higher areas that appear to be polygons.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Diffusion accessibility as a method for visualizing macromolecular surface geometry.

PubMed

Tsai, Yingssu; Holton, Thomas; Yeates, Todd O

2015-10-01

Important three-dimensional spatial features such as depth and surface concavity can be difficult to convey clearly in the context of two-dimensional images. In the area of macromolecular visualization, the computer graphics technique of ray-tracing can be helpful, but further techniques for emphasizing surface concavity can give clearer perceptions of depth. The notion of diffusion accessibility is well-suited for emphasizing such features of macromolecular surfaces, but a method for calculating diffusion accessibility has not been made widely available. Here we make available a web-based platform that performs the necessary calculation by solving the Laplace equation for steady state diffusion, and produces scripts for visualization that emphasize surface depth by coloring according to diffusion accessibility. The URL is http://services.mbi.ucla.edu/DiffAcc/. © 2015 The Protein Society.

A case study on the perception of aging and participation in physical activities of older Chinese immigrants in Australia.

PubMed

Koo, Fung Kuen

2011-10-01

This qualitative study explores how older Hong Kong ChineseAustralians perceive aging and to what extent this perception affects their participation in physical activities. The main methods used were in-depth interviews with 22 participants ranging in age from 60 to 91 years. Interviews were translated from Chinese (Cantonese) and transcribed into English. Content analysis was used to find recurring themes from the interview data. The main findings indicate that the perception of aging is to some extent influenced by culture. Some participants defined aging as being measured in years, and others defined it by the state of one's physical health, appearance, and capacity to continue fulfilling one's social roles. These perceptions strongly influenced their preferences for and participation in physical activities. Acknowledging the fact that Chinese-speaking people are not culturally homogeneous, this article makes some recommendations to health service providers with regard to the development of appropriate physical activity programs.

Weighted parallel contributions of binocular correlation and match signals to conscious perception of depth

PubMed Central

2016-01-01

Binocular disparity is detected in the primary visual cortex by a process similar to calculation of local cross-correlation between left and right retinal images. As a consequence, correlation-based neural signals convey information about false disparities as well as the true disparity. The false responses in the initial disparity detectors are eliminated at later stages in order to encode only disparities of the features correctly matched between the two eyes. For a simple stimulus configuration, a feed-forward nonlinear process can transform the correlation signal into the match signal. For human observers, depth judgement is determined by a weighted sum of the correlation and match signals rather than depending solely on the latter. The relative weight changes with spatial and temporal parameters of the stimuli, allowing adaptive recruitment of the two computations under different visual circumstances. A full transformation from correlation-based to match-based representation occurs at the neuronal population level in cortical area V4 and manifests in single-neuron responses of inferior temporal and posterior parietal cortices. Neurons in area V5/MT represent disparity in a manner intermediate between the correlation and match signals. We propose that the correlation and match signals in these areas contribute to depth perception in a weighted, parallel manner. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269600

Weighted parallel contributions of binocular correlation and match signals to conscious perception of depth.

PubMed

Fujita, Ichiro; Doi, Takahiro

2016-06-19

Binocular disparity is detected in the primary visual cortex by a process similar to calculation of local cross-correlation between left and right retinal images. As a consequence, correlation-based neural signals convey information about false disparities as well as the true disparity. The false responses in the initial disparity detectors are eliminated at later stages in order to encode only disparities of the features correctly matched between the two eyes. For a simple stimulus configuration, a feed-forward nonlinear process can transform the correlation signal into the match signal. For human observers, depth judgement is determined by a weighted sum of the correlation and match signals rather than depending solely on the latter. The relative weight changes with spatial and temporal parameters of the stimuli, allowing adaptive recruitment of the two computations under different visual circumstances. A full transformation from correlation-based to match-based representation occurs at the neuronal population level in cortical area V4 and manifests in single-neuron responses of inferior temporal and posterior parietal cortices. Neurons in area V5/MT represent disparity in a manner intermediate between the correlation and match signals. We propose that the correlation and match signals in these areas contribute to depth perception in a weighted, parallel manner.This article is part of the themed issue 'Vision in our three-dimensional world'. © 2016 The Author(s).

Domestic waste disposal practice and perceptions of private sector waste management in urban Accra

PubMed Central

2014-01-01

Background Waste poses a threat to public health and the environment if it is not stored, collected, and disposed of properly. The perception of waste as an unwanted material with no intrinsic value has dominated attitudes towards disposal. This study investigates the domestic waste practices, waste disposal, and perceptions about waste and health in an urban community. Methods The study utilised a mixed-method approach. A cross-sectional survey questionnaire and in-depth interview were used to collect data. A total of 364 household heads were interviewed in the survey and six key informants were interviewed with the in-depth interviews. Results The results of the study revealed that 93.1% of households disposed of food debris as waste and 77.8% disposed of plastic materials as waste. The study also showed that 61.0% of the households disposed of their waste at community bins or had waste picked up at their homes by private contractors. The remaining 39.0% disposed of their waste in gutters, streets, holes and nearby bushes. Of those who paid for the services of private contractors, 62.9% were not satisfied with the services because of their cost and irregular collection. About 83% of the respondents were aware that improper waste management contributes to disease causation; most of the respondents thought that improper waste management could lead to malaria and diarrhoea. There was a general perception that children should be responsible for transporting waste from the households to dumping sites. Conclusion Proper education of the public, the provision of more communal trash bins, and the collection of waste by private contractors could help prevent exposing the public in municipalities to diseases. PMID:25005728

Domestic waste disposal practice and perceptions of private sector waste management in urban Accra.

PubMed

Yoada, Ramatta Massa; Chirawurah, Dennis; Adongo, Philip Baba

2014-07-08

Waste poses a threat to public health and the environment if it is not stored, collected, and disposed of properly. The perception of waste as an unwanted material with no intrinsic value has dominated attitudes towards disposal. This study investigates the domestic waste practices, waste disposal, and perceptions about waste and health in an urban community. The study utilised a mixed-method approach. A cross-sectional survey questionnaire and in-depth interview were used to collect data. A total of 364 household heads were interviewed in the survey and six key informants were interviewed with the in-depth interviews. The results of the study revealed that 93.1% of households disposed of food debris as waste and 77.8% disposed of plastic materials as waste. The study also showed that 61.0% of the households disposed of their waste at community bins or had waste picked up at their homes by private contractors. The remaining 39.0% disposed of their waste in gutters, streets, holes and nearby bushes. Of those who paid for the services of private contractors, 62.9% were not satisfied with the services because of their cost and irregular collection. About 83% of the respondents were aware that improper waste management contributes to disease causation; most of the respondents thought that improper waste management could lead to malaria and diarrhoea. There was a general perception that children should be responsible for transporting waste from the households to dumping sites. Proper education of the public, the provision of more communal trash bins, and the collection of waste by private contractors could help prevent exposing the public in municipalities to diseases.

A Depth Map Generation Algorithm Based on Saliency Detection for 2D to 3D Conversion

NASA Astrophysics Data System (ADS)

Yang, Yizhong; Hu, Xionglou; Wu, Nengju; Wang, Pengfei; Xu, Dong; Rong, Shen

2017-09-01

In recent years, 3D movies attract people's attention more and more because of their immersive stereoscopic experience. However, 3D movies is still insufficient, so estimating depth information for 2D to 3D conversion from a video is more and more important. In this paper, we present a novel algorithm to estimate depth information from a video via scene classification algorithm. In order to obtain perceptually reliable depth information for viewers, the algorithm classifies them into three categories: landscape type, close-up type, linear perspective type firstly. Then we employ a specific algorithm to divide the landscape type image into many blocks, and assign depth value by similar relative height cue with the image. As to the close-up type image, a saliency-based method is adopted to enhance the foreground in the image and the method combine it with the global depth gradient to generate final depth map. By vanishing line detection, the calculated vanishing point which is regarded as the farthest point to the viewer is assigned with deepest depth value. According to the distance between the other points and the vanishing point, the entire image is assigned with corresponding depth value. Finally, depth image-based rendering is employed to generate stereoscopic virtual views after bilateral filter. Experiments show that the proposed algorithm can achieve realistic 3D effects and yield satisfactory results, while the perception scores of anaglyph images lie between 6.8 and 7.8.

Between normality and deviance: the breakdown of batterers' identity following police intervention.

PubMed

Buchbinder, Eli; Eisikovits, Zvi

2004-04-01

With the transformation of intimate violence from private trouble to social problem, police intervention in domestic violence cases became more prevalent. Research has focused mainly on battered women's perception of police intervention, their evaluations, and their level of satisfaction with the intervention. However, there is little research examining the perpetrators' subjective perceptions of such interventions. The purpose of this study is to describe and analyze battering men's perceptions of police intervention. The study is based on semistructured, in-depth interviews with 20 batterers who had repeated encounters with police. Findings show a continuum of self-management, ranging from attempts to preserve a normative identity in the first encounter to struggling against criminalization in the second encounter and adopting a victim identity in the third encounter. The findings are discussed in the context of gender identity and power relations.

Consumer Perception of the Food and Drug Administration's Newest Recommended Food Facility Inspection Format: Words Matter.

PubMed

Kim, Jooho; Ma, Jing; Almanza, Barbara

2017-06-01

The Food and Drug Administration recommended restaurant inspection scores change to a format that incorporated three new categories of violations: priority, priority foundation, and core. It was uncertain whether interested consumers would value the more in-depth information or become more confused. The purpose of this study was to assess consumer perception of the recommended inspection system. Data were collected from an online survey. Results showed that consumers want convenient access to the information either online or on the wall of restaurants, and some consumers do want to read inspection reports and use them in making dining decisions. Choice of restaurant inspection format did appear to change consumer understanding and perceptions about some of the violations. Results also demonstrated the importance of the words used to categorize violations.

Interaction of color and geometric cues in depth perception: when does "red" mean "near"?

PubMed

Guibal, Christophe R C; Dresp, Birgitta

2004-12-01

Luminance and color are strong and self-sufficient cues to pictorial depth in visual scenes and images. The present study investigates the conditions under which luminance or color either strengthens or overrides geometric depth cues. We investigated how luminance contrast associated with the color red and color contrast interact with relative height in the visual field, partial occlusion, and interposition to determine the probability that a given figure presented in a pair is perceived as "nearer" than the other. Latencies of "near" responses were analyzed to test for effects of attentional selection. Figures in a pair were supported by luminance contrast (Experiment 1) or isoluminant color contrast (Experiment 2) and combined with one of the three geometric cues. The results of Experiment 1 show that the luminance contrast of a color (here red), when it does not interact with other colors, produces the same effects as achromatic luminance contrasts. The probability of "near" increases with the luminance contrast of the color stimulus, the latencies for "near" responses decrease with increasing luminance contrast. Partial occlusion is found to be a strong enough pictorial cue to support a weaker red luminance contrast. Interposition cues lose out against cues of spatial position and partial occlusion. The results of Experiment 2, with isoluminant displays of varying color contrast, reveal that red color contrast on a light background supported by any of the three geometric cues wins over green or white supported by any of the three geometric cues. On a dark background, red color contrast supported by the interposition cue loses out against green or white color contrast supported by partial occlusion. These findings reveal that color is not an independent depth cue, but is strongly influenced by luminance contrast and stimulus geometry. Systematically shorter response latencies for stronger "near" percepts demonstrate that selective visual attention reliably detects the most likely depth cue combination in a given configuration.

Mapping the opacity of paint layers in paintings with coloured grounds using optical coherence tomography

NASA Astrophysics Data System (ADS)

Liu, Ping; Hall-Aquitania, Moorea; Hermens, Erma; Groves, Roger M.

2017-07-01

Optical diagnostics techniques are becoming important for technical art history (TAH) as well as for heritage conservation. In recent years, optical coherence tomography (OCT) has been increasingly used as a novel technique for the inspection of artwork, revealing the stratigraphy of paintings. It has also shown to be an effective tool for vanish layer inspection. OCT is a contactless and non-destructive technique for microstructural imaging of turbid media, originally developed for medical applications. However current OCT instruments have difficulty in paint layer inspection due to the opacity of most pigments. This paper explores the potential of OCT for the investigation of paintings with coloured grounds. Depth scans were processed to determine the light penetration depth at the optical wavelength based on a 1/e light attenuation calculation. The variation in paint opacity was mapped based on the microstructural images and 3D penetration depth profiles was calculated and related back to the construction of the artwork. By determining the light penetration depth over a range of wavelengths the 3D depth perception of a painting with coloured grounds can be characterized optically.

Motion perception and driving: predicting performance through testing and shortening braking reaction times through training.

PubMed

Wilkins, Luke; Gray, Rob; Gaska, James; Winterbottom, Marc

2013-12-30

A driving simulator was used to examine the relationship between motion perception and driving performance. Although motion perception test scores have been shown to be related to driving safety, it is not clear which combination of tests are the best predictors and whether motion perception training can improve driving performance. In experiment 1, 60 younger drivers (22.4 ± 2.5 years) completed three motion perception tests (2-dimensional [2D] motion-defined letter [MDL] identification, 3D motion in depth sensitivity [MID], and dynamic visual acuity [DVA]) followed by two driving tests (emergency braking [EB] and hazard perception [HP]). In experiment 2, 20 drivers (21.6 ± 2.1 years) completed 6 weeks of motion perception training (using the MDL, MID, and DVA tests), while 20 control drivers (22.0 ± 2.7 years) completed an online driving safety course. The EB performance was measured before and after training. In experiment 1, MDL (r = 0.34) and MID (r = 0.46) significantly correlated with EB score. The change in DVA score as a function of target speed (i.e., "velocity susceptibility") was correlated most strongly with HP score (r = -0.61). In experiment 2, the motion perception training group had a significant decrease in brake reaction time on the EB test from pre- to posttreatment, while there was no significant change for the control group: t(38) = 2.24, P = 0.03. Tests of 3D motion perception are the best predictor of EB, while DVA velocity susceptibility is the best predictor of hazard perception. Motion perception training appears to result in faster braking responses.

Chinese Students' Perceptions of Native English-Speaking Teachers in EFL Teaching

ERIC Educational Resources Information Center

Rao, Zhenhui

2010-01-01

The article reports the views of 20 Chinese English as a foreign Language (EFL) students on the strengths and weaknesses of native English-speaking (NES) teachers in EFL teaching. Responding to an open-ended questionnaire and in-depth interviews, EFL students named the following as NES teachers' strengths: native language authenticity, cultural…

Self-Perceptions of Interpersonal, Intrapersonal, and Leadership Skills among Recent Engineering Graduates: A Qualitative Study

ERIC Educational Resources Information Center

Watson, Fallon E.

2013-01-01

This study describes the communication-specific soft skills that recent engineering graduates from Accreditation Board for Engineering and Technology (ABET) accredited universities in the state of Kentucky report they use at work. Utilizing a basic interpretive qualitative approach in-depth semi-structured interviews were conducted to obtain the…

Reconsidering the Workplace: Faculty Perceptions of Their Work and Working Environments

ERIC Educational Resources Information Center

Kuntz, Aaron M.

2012-01-01

In an effort to foreground the impact of the material environment on faculty activities, this study examines the dynamic intersections among faculty work practices, the academic workplace and professional identity. Drawing on in-depth interviews with 16 social science faculty at one public university in the United States, this study reveals the…

Understanding of Epilepsy by Children and Young People with Epilepsy

ERIC Educational Resources Information Center

Lewis, Ann; Parsons, Sarah

2008-01-01

There is a striking dearth of studies focusing sensitively and in depth on the mainstream educational experiences of children with epilepsy, as viewed by those children themselves. The one-year project (2006-7) reported here addresses that gap. Children's perceptions about mainstream teachers' understanding of epilepsy and school-based needs are…

"I'd Rather Watch TV": An Examination of Physical Activity in Adults with Mental Retardation

ERIC Educational Resources Information Center

Frey, Georgia C.; Buchanan, Alice M.; Rosser Sandt, Dawn D.

2005-01-01

Interpretive ethnography was used as a framework to examine perceptions of physical activity behavior of 12 adults with mild mental retardation. Four parents and two job supervisors also agreed to participate. Multiple data sources included in-depth interviews, diaries, accelerometry, and informal observations. Participants reported many physical…

Booni Valley Women's Perceptions of Schooling: Hopes and Barriers

ERIC Educational Resources Information Center

Pardhan, Almina

2005-01-01

Schooling for girls is a relatively recent process in Booni Valley, a remote mountainous village in Chitral District, Pakistan. It is impacting greatly upon the lives of the women. This study has taken an ethnographic perspective and has assumed that an understanding of women's schooling requires a detailed, in-depth account of women's actual…

Sources of Stress: Perceptions of South African TESOL Teachers

ERIC Educational Resources Information Center

Bowen, Amanda

2016-01-01

This paper presents the findings of a qualitative study investigating which factors inside and outside the classroom result in feelings of stress for TESOL teachers working at private language schools in South Africa. Using in-depth semi-structured interviews, the findings reveal three main areas that cause stress for TESOL teachers: the job of…

Providers' Perceptions of and Receptivity toward Evidence-Based HIV Prevention Interventions

ERIC Educational Resources Information Center

Owczarzak, Jill; Dickson-Gomez, Julia

2011-01-01

Since 1999, the Centers for Disease Control and Prevention have trained over 10,000 service providers from more than 5,000 agencies to implement evidence-based HIV prevention interventions through its Diffusion of Effective Behavioral Interventions DEBI) program. Based on in-depth, semistructured interviews with a convenience sample of 22 HIV…

Experience of Adult Facilitators in a Virtual-Reality-Based Social Interaction Program for Children with Autism

ERIC Educational Resources Information Center

Ke, Fengfeng; Im, Tami; Xue, Xinrong; Xu, Xinhao; Kim, Namju; Lee, Sungwoong

2015-01-01

This phenomenological study explored and described the experiences and perceptions of adult facilitators who facilitated virtual-reality-based social interaction for children with autism. Extensive data were collected from iterative, in-depth interviews; online activities observation; and video analysis. Four salient themes emerged through the…

Mainstream Teachers' Experiences of Communicating with Students with Multiple and Severe Disabilities

ERIC Educational Resources Information Center

De Bortoli, Tania; Balandin, Susan; Foreman, Phil; Arthur-Kelly, Michael; Mathisen, Bernice

2012-01-01

The aim of this study was to explore regular teachers' perceptions and experiences of supports and obstacles to communicative interactions for students with multiple and severe disabilities (MSD). Five teachers of students with MSD participated in two in-depth interviews. Interview transcripts were analysed using content analysis. Transcripts were…

Physical Activity during Physical Education Lessons: A Qualitative Investigation of Australian PE Teacher Perceptions

ERIC Educational Resources Information Center

Bennie, Andrew; Langan, Edel

2015-01-01

School physical education (PE) experiences play a critical role in adolescents' physical activity (PA) levels. Teachers are crucial to students' initial experiences in PA; however, limited research has explored teachers' perspectives about PA during PE using in-depth qualitative research techniques. We conducted interviews with 25 current…

Beyond the Evident Content Goals Part I. Tapping the Depth and Flow of the Educational Undercurrent.

ERIC Educational Resources Information Center

Dugdale, Sharon; Kibbey, David

1990-01-01

The first in a series of three articles, successful instructional materials from a 15-year software development effort are analyzed and characterized with special attention given to educational experiences intended to shape students' perceptions of the fundamental nature, interconnectedness, and usefulness of mathematics. The software programs…

School Counselors' Perceptions of Differences between Successful and Less Successful Latina/o High School Students

ERIC Educational Resources Information Center

Vela, Javier Cavazos; Lu, Ming-Tsan P.; Gonzalez, Stacey L.; Smith, Robert L.; Azadi-Setayesh, Shaghayegh

2015-01-01

In this qualitative study, we conducted in-depth interviews with secondary school counselors to understand differences between successful and less successful Latina/o students. Using an ecological framework as a theoretical lens, we highlighted differences between successful and less successful Latina/o high school students consistent with…

Professional Integrity in Higher Education: A Study of Administrative Staff Ethics in Student Affairs

ERIC Educational Resources Information Center

Reybold, L. Earle; Halx, Mark D.; Jimenez, Anne L.

2008-01-01

This study examined administrative staff perceptions of professional ethics in a student affairs division at one university. In-depth interviews were conducted with 12 staff members (six assistant/associate vice presidents and six directors) and analyzed using the constant comparative method. Participants described three dimensions of professional…

Race-ing through the School Day: African American Educators' Experiences with Race and Racism in Schools

ERIC Educational Resources Information Center

Jay, Michelle

2009-01-01

This article examines the ways African American educators experience themselves as raced individuals in their school settings and explores their perceptions of racial discrimination, subordination, and isolation. For this study, five African American educators participated in in-depth phenomenological interviews. Qualitative data analysis of their…

Using Transformative Learning as a Framework to Explore Women and Running

ERIC Educational Resources Information Center

Hayduk, Dina

2011-01-01

This qualitative narrative inquiry explored women's self-perceptions changed through regular participation in running. Transformative learning theory was considered as a possible explanation for the learning and changes adult women experienced. In-depth interviews of 11 adult women who have been running between 1 to 4 years were conducted. Based…

Employees' Perceptions of Cycle Commuting: A Qualitative Study

ERIC Educational Resources Information Center

van Bekkum, Jennifer E.; Williams, Joanne M.; Morris, Paul Graham

2011-01-01

Purpose: This study aims to provide an in-depth individual level understanding of the psychological factors that affect cycle commuting. Design/methodology/approach: A total of 15 participants (eight cycle commuters and seven potential cycle commuters) from a "cycle-friendly" employer based in a Scottish city took part in the study.…

Chinese Engineering Students' Cross-Cultural Adaptation in Graduate School

ERIC Educational Resources Information Center

Jiang, Xinquan

2010-01-01

This study explores cross-cultural adaptation experience of Chinese engineering students in the U.S. I interact with 10 Chinese doctoral students in engineering from a public research university through in-depth interviews to describe (1) their perceptions of and responses to key challenges they encountered in graduate school, (2) their…

Education, Wage Work, and Marriage: Perspectives of Egyptian Working Women

ERIC Educational Resources Information Center

Amin, Sajeda; Al-Bassusi, Nagah H.

2004-01-01

We explore young working women's perceptions of marriage and work in contemporary Egypt, when an increase in age at marriage was evident from national survey data. Both working conditions and employment opportunities declined significantly for young women even as their educational attainment increased and marriage was delayed. In-depth interviews…

How Academics in Undergraduate Business Programs at an Australian University View Sustainability

ERIC Educational Resources Information Center

von der Heidt, Tania; Lamberton, Geoffrey

2014-01-01

This article explores conceptualisations of sustainability and perceptions of its importance in curriculum held by business subject and program leaders. Results are reported from an empirical study of the first-year Bachelor of Business program at an Australian university. Research data was collected in 16 semi-structured, in-depth interviews with…

Politics and Paradox! The Case of an Urban Alternative

ERIC Educational Resources Information Center

Tallerico, Marilyn; Burstyn, Joan N.

2005-01-01

In recent decades, a number of factors have contributed to the growth of alternative educational programs in urban settings. Public perception of cities as dangerous places and national media attention to high profile incidents of school violence are two influences. Here, Tallerico and Burstyn center on a subset of in-depth interview data provided…

Perspective Taking through Film: Educating Pre-Service and In-Service Teachers about Autism

ERIC Educational Resources Information Center

Kelleher, Jacqueline P.

2015-01-01

When it comes to educating students with autism in the classroom, teachers' perceptions and attitudes toward inclusion are essential. Professional development that enhances perspective taking about autism is powerful if it leads to depth of understanding and action. Instructional media can play a role in raising viewer awareness; unfortunately,…

A Breath of Fresh Air: Students' Perceptions of Interactions with African American Faculty

ERIC Educational Resources Information Center

Neville, Kathleen M.; Parker, Tara L.

2017-01-01

In this phenomenological study we relied on classroom observations and 22 in-depth interviews with students as they interacted with African American faculty. Findings reveal the meaning students made from these classroom interactions and the ways African American faculty, significantly and positively, influenced the student experience. More…

Que Gacho Es Ser Macho: It's a Drag to Be a Macho Man.

ERIC Educational Resources Information Center

Mirande, Alfredo

1986-01-01

Focuses on variations in perceptions and conceptions of machismo within Mexican and Latino culture. Studies how Latino fathers living in United States perceive machismo, utilizing data from in-depth interviews. Identifies two models of masculinity, one as compensation for powerlessness, the other grounded in ethics, honor, and courage. (TES)

Binaural beat salience

PubMed Central

Grose, John H.; Buss, Emily; Hall, Joseph W.

2012-01-01

Previous studies of binaural beats have noted individual variability and response lability, but little attention has been paid to the salience of the binaural beat percept. The purpose of this study was to gauge the strength of the binaural beat percept by matching its salience to that of sinusoidal amplitude modulation (SAM), and to then compare rate discrimination for the two types of fluctuation. Rate discrimination was measured for standard rates of 4, 8, 16, and 32 Hz – all in the 500-Hz carrier region. Twelve normal-hearing adults participated in this study. The results indicated that discrimination acuity for binaural beats is similar to that for SAM tones whose depths of modulation have been adjusted to provide equivalent modulation salience. The matched-salience SAM tones had relatively shallow depths of modulation, suggesting that the perceptual strength of binaural beats is relatively weak, although all listeners perceived them. The Weber fraction for detection of an increase in binaural beat rate is roughly constant across beat rates, at least for rates above 4 Hz, as is rate discrimination for SAM tones. PMID:22326292

Binaural beat salience.

PubMed

Grose, John H; Buss, Emily; Hall, Joseph W

2012-03-01

Previous studies of binaural beats have noted individual variability and response lability, but little attention has been paid to the salience of the binaural beat percept. The purpose of this study was to gauge the strength of the binaural beat percept by matching its salience to that of sinusoidal amplitude modulation (SAM), and to then compare rate discrimination for the two types of fluctuation. Rate discrimination was measured for standard rates of 4, 8, 16, and 32 Hz - all in the 500-Hz carrier region. Twelve normal-hearing adults participated in this study. The results indicated that discrimination acuity for binaural beats is similar to that for SAM tones whose depths of modulation have been adjusted to provide equivalent modulation salience. The matched-salience SAM tones had relatively shallow depths of modulation, suggesting that the perceptual strength of binaural beats is relatively weak, although all listeners perceived them. The Weber fraction for detection of an increase in binaural beat rate is roughly constant across beat rates, at least for rates above 4 Hz, as is rate discrimination for SAM tones. Copyright © 2012 Elsevier B.V. All rights reserved.

Impact of floating windows on the accuracy of depth perception in games

NASA Astrophysics Data System (ADS)

Stanfield, Brodie; Zerebecki, Christopher; Hogue, Andrew; Kapralos, Bill; Collins, Karen

2013-03-01

The floating window technique is commonly employed by stereoscopic 3D filmmakers to reduce the effects of window violations by masking out portions of the screen that contain visual information that doesn't exist in one of the views. Although widely adopted in the film industry, and despite its potential benefits, the technique has not been adopted by video game developers to the same extent possibly because of the lack of understanding of how the floating window can be utilized in such an interactive medium. Here, we describe a quantitative study that investigates how the floating window technique affects users' depth perception in a simple game-like environment. Our goal is to determine how various stereoscopic 3D parameters such as the existence, shape, and size of the floating window affect the user experience and to devise a set of guidelines for game developers wishing to develop stereoscopic 3D content. Providing game designers with quantitative knowledge of how these parameters can affect user experience is invaluable when choosing to design interactive stereoscopic 3D content.

Perception and coping with stigma of mental illness: Arab families' perspectives.

PubMed

Dalky, Heyam F

2012-07-01

Family stigma is well documented in the research literature; however, it has only been recently that efforts have been undertaken to discuss the perception of stigma as reported by Arab families of relatives with mental illness. This clinical paper aims to identify families' perception of stigma related to mental illness, and to compare Arab families' approaches with various aspects of caring from different countries. Further, this paper discusses, in-depth, specific areas related to families' perceptions of stigma: What impacts does stigma perception have on those families and on their relatives' care outcomes and what are coping strategies are used to handle stigma and its impacts in such countries? This paper emphasizes that chronic mental illness contributes the most to families' perception of stigma. In this study, Arab families perceived the experience of caring for a family member with a mental illness with fear, loss, embarrassment, and disgrace of family reputations. Further, secrecy, isolation, despair, and helplessness were reported the most among different family groups in Jordan and Morocco. This paper reminds us that cultural norms and beliefs shape family members' perception of coping and their ability to manage caring for relatives with mental illnesses. Thus, more studies are needed concerning coping and management strategies that are culturally relevant. This could eventually guide the establishment of stigma reduction initiatives and expand understanding of stigma from different cultural perspectives.

Mind the gap! Lay and medical perceptions of risks associated with the use of alternative treatment and conventional medicine.

PubMed

Salamonsen, Anita

2015-01-01

Studies on the widespread use of complementary and alternative medicine (CAM) demonstrate that CAM users base their treatment decisions on both subjective, experience-based knowledge and medical knowledge. The aim of this study was to explore lay and medical risk perceptions associated with CAM and conventional medicine. In this explorative qualitative study, we conducted in-depth interviews with 25 Norwegian CAM users with cancer or multiple sclerosis and 12 doctors. The interviews revealed fundamental differences in risk perceptions influencing treatment decisions and risk communication in a clinical setting. While CAM users considered conventional medicine as potentially risky and related this to experiences of severe adverse effects, CAM was perceived as natural and safe. Doctors' risk perceptions were quite the contrary, mainly because of lack of scientific evidence for CAM as a safe and beneficial treatment option. For the safety of CAM users, such divergent risk perceptions may have far-reaching consequences. CAM users should be taken seriously with their self-perception as decision-makers considering their approaches to experiences, knowledge, and science. An awareness of differing lay and medical risk perceptions associated with CAM and conventional medicine in research, doctor-patient communication, and education of patients and doctors is thus important to optimize patient safety in complex health care systems. © 2015 S. Karger GmbH, Freiburg.

Use of cues in virtual reality depends on visual feedback.

PubMed

Fulvio, Jacqueline M; Rokers, Bas

2017-11-22

3D motion perception is of central importance to daily life. However, when tested in laboratory settings, sensitivity to 3D motion signals is found to be poor, leading to the view that heuristics and prior assumptions are critical for 3D motion perception. Here we explore an alternative: sensitivity to 3D motion signals is context-dependent and must be learned based on explicit visual feedback in novel environments. The need for action-contingent visual feedback is well-established in the developmental literature. For example, young kittens that are passively moved through an environment, but unable to move through it themselves, fail to develop accurate depth perception. We find that these principles also obtain in adult human perception. Observers that do not experience visual consequences of their actions fail to develop accurate 3D motion perception in a virtual reality environment, even after prolonged exposure. By contrast, observers that experience the consequences of their actions improve performance based on available sensory cues to 3D motion. Specifically, we find that observers learn to exploit the small motion parallax cues provided by head jitter. Our findings advance understanding of human 3D motion processing and form a foundation for future study of perception in virtual and natural 3D environments.

Perception of HIV/AIDS among the Igbo of Anambra State, Nigeria

PubMed Central

Muoghalu, Caroline Okumdi; Jegede, Samuel Ayodele

2013-01-01

Perception is fundamental in the fight against stigmatization of people living with HIV/AIDS (PLHIV). Perception generally influences discriminatory attitudes towards PLHIV which exacerbates their problems and quickens the degeneration of the disease from HIV to AIDS. This study examined the Anambra people's perception and knowledge of HIV/AIDS with the goal of creating knowledge on these issues in order to design effective intervention programmes towards the reduction of social stigmatization associated with the pandemic. The study was carried out in Idemmili North and Oyi local government areas of Anambra State. Qualitative and quantitative methodologies were used to elicit information from respondents who were adult males and females of 18 years and above. The research instruments were questionnaires and in-depth interview schedule. Questionnaires were administered on 1000 respondents while 13 people were interviewed in-depth. Analysis of quantitative data were conducted by using the Statistical package for Social Sciences. Univariate analysis in the form of frequencies were conducted which generated the distribution of respondents across the research variables. Furthermore, multivariate analysis were conducted to test the hypotheses and sought for relationships among variables. The qualitative data were reported in themes based on the research objectives and were analysed jointly with the quantitative data. The findings were that majority of the respondents viewed HIV/AIDS as a disease that afflict immoral people and as a punishment from God. Only a handful of them saw the disease as a disease that could afflict anybody. Also, many of the respondents said that AIDS is real but showed a low level of knowledge. It was further indicated that there were significant relationships between educational level, sex, occupation, income influence perception and peoples' reactions to HIV positive status of a relative while there were no significant relationships between these variables and knowledge of HIV/AIDS. It was concluded that these negative perceptions were as a result of the people's low level of knowledge and cultural belief systems, which see a strange illness as punishment from God for disobedience. Furthermore, the fact that most of the socio-economic characteristics of the respondents had significant relationship with perception and reaction to HIV was an indication that most people in the study area had a uniform perception. It was also an indication that government HIV/AIDS awareness programmes were not effective. It was recommended that strategies for effective HIV educational programme should be sought and carried out in the study area. Effective intervention programme have the power to change behaviours and would likely change the people's negative perception and low level of knowledge of HIV/AIDS, thereby reducing stigmatization of people living with HIV/AIDS. PMID:23808412

Perception of HIV/AIDS among the Igbo of Anambra State, Nigeria.

PubMed

Muoghalu, Caroline Okumdi; Jegede, Samuel Ayodele

2013-03-01

Perception is fundamental in the fight against stigmatization of people living with HIV/AIDS (PLHIV). Perception generally influences discriminatory attitudes towards PLHIV which exacerbates their problems and quickens the degeneration of the disease from HIV to AIDS. This study examined the Anambra people's perception and knowledge of HIV/AIDS with the goal of creating knowledge on these issues in order to design effective intervention programmes towards the reduction of social stigmatization associated with the pandemic. The study was carried out in Idemmili North and Oyi local government areas of Anambra State. Qualitative and quantitative methodologies were used to elicit information from respondents who were adult males and females of 18 years and above. The research instruments were questionnaires and in-depth interview schedule. Questionnaires were administered on 1000 respondents while 13 people were interviewed in-depth. Analysis of quantitative data were conducted by using the Statistical package for Social Sciences. Univariate analysis in the form of frequencies were conducted which generated the distribution of respondents across the research variables. Furthermore, multivariate analysis were conducted to test the hypotheses and sought for relationships among variables. The qualitative data were reported in themes based on the research objectives and were analysed jointly with the quantitative data. The findings were that majority of the respondents viewed HIV/AIDS as a disease that afflict immoral people and as a punishment from God. Only a handful of them saw the disease as a disease that could afflict anybody. Also, many of the respondents said that AIDS is real but showed a low level of knowledge. It was further indicated that there were significant relationships between educational level, sex, occupation, income influence perception and peoples' reactions to HIV positive status of a relative while there were no significant relationships between these variables and knowledge of HIV/AIDS. It was concluded that these negative perceptions were as a result of the people's low level of knowledge and cultural belief systems, which see a strange illness as punishment from God for disobedience. Furthermore, the fact that most of the socio-economic characteristics of the respondents had significant relationship with perception and reaction to HIV was an indication that most people in the study area had a uniform perception. It was also an indication that government HIV/AIDS awareness programmes were not effective. It was recommended that strategies for effective HIV educational programme should be sought and carried out in the study area. Effective intervention programme have the power to change behaviours and would likely change the people's negative perception and low level of knowledge of HIV/AIDS, thereby reducing stigmatization of people living with HIV/AIDS.

Perceptions about Authentic Leadership Development: South African Occupational Therapy Students' Camp Experience

PubMed Central

2018-01-01

Background Twenty-three years into democracy, concern is deepening regarding the slow progress of Occupational Therapy (OT) in South Africa, especially with regard to diversity and inclusion within OT. Methods This study explores authentic leadership development primarily among Black OT students attending a pilot Occupational Therapy Association of South Africa (OTASA) National Student Leadership Camp. It seeks to ascertain their perceptions on leadership and leadership development. This descriptive pilot study employs in-depth interviews and subsequent content analysis, with 12 OT students from six university OT programs in South Africa. Findings Four categories of participant perceptions on authentic leadership development emerged from the analysis: (1) perceptions about oneself as a leader based on personal narrative, self-awareness, self-control, and psychological capital; (2) perceptions about others, specifically current leaders, with regard to their moral crisis, including continuing inequality, insincerity, greed, and selfishness; (3) goals and aspirations for leadership development via student camps; and (4) effects of leadership on the system. Conclusions Recommendations for future practice include promotion of storytelling as a means of personal reflection for authentic leadership development and focused investment in camps for developing student leadership skills and building authentic leadership knowledge. PMID:29770106

Perceptions about Authentic Leadership Development: South African Occupational Therapy Students' Camp Experience.

PubMed

Hendricks, Fatima; Toth-Cohen, Susan

2018-01-01

Twenty-three years into democracy, concern is deepening regarding the slow progress of Occupational Therapy (OT) in South Africa, especially with regard to diversity and inclusion within OT. This study explores authentic leadership development primarily among Black OT students attending a pilot Occupational Therapy Association of South Africa (OTASA) National Student Leadership Camp. It seeks to ascertain their perceptions on leadership and leadership development. This descriptive pilot study employs in-depth interviews and subsequent content analysis, with 12 OT students from six university OT programs in South Africa. Four categories of participant perceptions on authentic leadership development emerged from the analysis: (1) perceptions about oneself as a leader based on personal narrative, self-awareness, self-control, and psychological capital; (2) perceptions about others, specifically current leaders, with regard to their moral crisis, including continuing inequality, insincerity, greed, and selfishness; (3) goals and aspirations for leadership development via student camps; and (4) effects of leadership on the system. Recommendations for future practice include promotion of storytelling as a means of personal reflection for authentic leadership development and focused investment in camps for developing student leadership skills and building authentic leadership knowledge.

Good, Bad or Absent: Discourses of Parents with Disabilities in Australian News Media.

PubMed

Fraser, Vikki; Llewellyn, Gwynnyth

2015-07-01

News media frames public perceptions. As such, news media becomes a useful source of analysis to understand the presence (or otherwise) of people with disabilities, particularly intellectual disabilities, within parenting discourses in Australia. Using Critical Discourse Analysis, this article examines major Australian newspapers over the period from January 2004 to December 2008, critiquing the construction of parenting and disability. A small number of articles are examined in close depth for tone, polarity syntactic and paradigmatic choice, deconstructing the underlying discourses that shape the article and thereby popular perceptions of parenting and disability. Discourses of care and child protection are emphasized in news articles about parenting, creating perceptions that negate the role of people with disabilities as parents. Such perceptions result in a systematic symbolic castration of people with intellectual disabilities from the role of parent in Australian society. By providing a framework for understanding the public perceptions of parents with disabilities (particularly intellectual disabilities), this paper demonstrates that changes are necessary in Australian media reporting on parents with disabilities to bring such reporting more closely in line with the United Nations Convention on the Rights of Persons with Disabilities, 2006. © 2015 John Wiley & Sons Ltd.

Signs of depth-luminance covariance in 3-D cluttered scenes.

PubMed

Scaccia, Milena; Langer, Michael S

2018-03-01

In three-dimensional (3-D) cluttered scenes such as foliage, deeper surfaces often are more shadowed and hence darker, and so depth and luminance often have negative covariance. We examined whether the sign of depth-luminance covariance plays a role in depth perception in 3-D clutter. We compared scenes rendered with negative and positive depth-luminance covariance where positive covariance means that deeper surfaces are brighter and negative covariance means deeper surfaces are darker. For each scene, the sign of the depth-luminance covariance was given by occlusion cues. We tested whether subjects could use this sign information to judge the depth order of two target surfaces embedded in 3-D clutter. The clutter consisted of distractor surfaces that were randomly distributed in a 3-D volume. We tested three independent variables: the sign of the depth-luminance covariance, the colors of the targets and distractors, and the background luminance. An analysis of variance showed two main effects: Subjects performed better when the deeper surfaces were darker and when the color of the target surfaces was the same as the color of the distractors. There was also a strong interaction: Subjects performed better under a negative depth-luminance covariance condition when targets and distractors had different colors than when they had the same color. Our results are consistent with a "dark means deep" rule, but the use of this rule depends on the similarity between the color of the targets and color of the 3-D clutter.

The effects of phase on the perception of 3D shape from texture: psychophysics and modeling.

PubMed

Thaler, Lore; Todd, James T; Dijkstra, Tjeerd M H

2007-02-01

Two experiments are reported in which observers judged the apparent shapes of elliptical cylinders with eight different textures that were presented with scrambled and unscrambled phase spectra. The results revealed that the apparent depths of these surfaces varied linearly with the ground truth in all conditions, and that the overall magnitude of surface relief was systematically underestimated. In general, the apparent depth of a surface is significantly attenuated when the phase spectrum of its texture is randomly scrambled, though the magnitude of this effect varies for different types of texture. A new computational model of 3D shape from texture is proposed in which apparent depth is estimated from the relative density of edges in different local regions of an image, and the predictions of this model are highly correlated with the observers' judgments.

Association of Knowledge and Cultural Perceptions of Malaysian Women with Delay in Diagnosis and Treatment of Breast Cancer: a Systematic Review.

PubMed

Khan, Tahir Mehmood; Leong, Jamie Pik Yan; Ming, Long Chiau; Khan, Amer Hayat

2015-01-01

Breast cancer is the most common cancer and the leading cause of cancer mortality among women of all ethnic and age groups in Malaysia. Delay in seeking help for breast cancer symptoms is preventable and by identifying possible factors for delayed diagnosis, patient prognosis and survival rates could be improved. This narrative review aimed to understand and evaluate the level of in-depth breast cancer knowledge in terms of clinical breast examination and breast self-examination, and other important aspects such as side-effects and risk factors in Malaysian females. Since Malaysia is multicultural, this review assessed social perceptions, cultural beliefs and help-seeking behaviour in respect to breast cancer among different ethnic groups, since these may impinge on efforts to 'avoid' the disease. A comprehensive literature search of seven databases was performed from December 2015 to January 2015. Screening of relevant published journals was also undertaken to identify available information related to the knowledge, perception and help-seeking behaviour of Malaysian women in relation to breast cancer. A total of 42 articles were appraised and included in this review. Generally, women in Malaysia had good awareness of breast cancer and its screening tools, particularly breast self-examination, but only superficial in-depth knowledge about the disease. Women in rural areas had lower levels of knowledge than those in urban areas. It was also shown that books, magazines, brochures and television were among the most common sources of breast cancer information. Delay in presentation was attributed mainly to a negative social perception of the disease, poverty, cultural and religion practices, and a strong influence of complementary and alternative medicine, rather than a lack of knowledge. This review highlighted the need for an intensive and in-depth breast cancer education campaigns using media and community health programmes, even with the existing good awareness of breast cancer. This is essential in order to avoid misconceptions and to frame the correct mind-set about breast cancer among women in Malaysia. Socio-cultural differences and religious practices should be taken into account by health care professionals when advising on breast cancer. Women need to be aware of the risk factors and symptoms of breast cancer so that early diagnosis can take place and the chances of survival improved.

Effect of color on pilot performance and transfer functions using a full-spectrum, calligraphic, color display system

NASA Technical Reports Server (NTRS)

Chase, W. D.

1976-01-01

The use of blue and red color in out-of-window cockpit displays, in full-spectrum calligraphic computer-generated display systems, is studied with attention given to pilot stereographic depth perception and response to visual cues. Displays for vertical approach, with dynamic and frozen-range landing approach and perspective arrays, are analyzed. Pilot transfer function and the transfer function associated with the contrasted approach and perspective arrays are discussed. Out-of-window blue lights are perceived by pilots as indicating greater distance depth, red lights as indicating proximity. The computer-generated chromatic display was adapted to flight simulators for the tests.

Reversed stereo depth and motion direction with anti-correlated stimuli.

PubMed

Read, J C; Eagle, R A

2000-01-01

We used anti-correlated stimuli to compare the correspondence problem in stereo and motion. Subjects performed a two-interval forced-choice disparity/motion direction discrimination task for different displacements. For anti-correlated 1d band-pass noise, we found weak reversed depth and motion. With 2d anti-correlated stimuli, stereo performance was impaired, but the perception of reversed motion was enhanced. We can explain the main features of our data in terms of channels tuned to different spatial frequencies and orientation. We suggest that a key difference between the solution of the correspondence problem by the motion and stereo systems concerns the integration of information at different orientations.

Responsibility and risk: understanding how PSA messages can encourage condom use.

PubMed

Treise, D M; Weigold, M F; Gotthoffer, A R; Prolman, C

1999-01-01

This article qualitatively examines how female college students interpret their responsibility for maintaining healthy sexual behaviors. A series of nine in-depth interviews was conducted to assess their perceptions on a broad range of sexual health topics including personal fears, relationships, monogamy, and sexual relationships. In addition, the paper addresses how these women negotiate condom use, responsibility issues regarding this negotiation, and perceived risk for contracting AIDS during unprotected sex. This study has implications for health educators, as well as for designers of public service advertisements, as it provides an in-depth look at why college women do not use protection even when it is available to them.

Experiences with, perceptions of and attitudes towards traditional Korean medicine (TKM) in patients with chronic fatigue: a qualitative, one-on-one, in-depth interview study.

PubMed

Son, Haeng-Mi; Park, Eun Young; Kim, Duck Hee; Kim, Eunjeong; Shin, Mi-Suk; Kim, Tae-Hun

2015-09-08

To explore perceptions and experiences of patients with chronic fatigue with traditional Korean medicine (TKM) and their motivation for choosing TKM. Qualitative, one-on-one, in-depth interview study. Primary TKM hospitals in Seoul, Incheon and Daejeon, South Korea. 15 patients with chronic fatigue were interviewed in this study. Patients with chronic fatigue experienced physical and psychological symptoms that resulted in severe difficulties associated with routine daily activities. The motivations for choosing TKM were primarily dissatisfaction with conventional medicine and previous positive experiences with TKM. While undergoing TKM treatment, patients found that TKM practitioners considered fatigue to be a treatable illness; also, patients felt comfortable with the doctor-patient relationship in TKM. Healthcare providers need to be concerned about the symptoms of chronic fatigue to a degree that is in line with the patient's own perceptions. Korean patients with chronic fatigue choose TKM as an alternative to fulfil their long-term needs that were unmet by conventional medicine, and they are greatly positively influenced by TKM. TKM may present a possible therapy to alleviate symptoms of diseases that conventional medicine does not address and is an approach that has a considerable effect on Korean patients. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Distortion of Prospective Time Production Underwater.

PubMed

Hobbs, Malcolm B; Kneller, Wendy

2017-07-01

The few prior studies of time perception underwater have reached contradictory conclusions as to how, and if, time perception becomes distorted when submerged. The current paper expands upon this limited data by describing two studies of prospective time production in scuba divers. Study 1 (N = 32) compared performance on a 30-s interval time production task in deep water (35 m-42 m/∼115-138 ft) with a shallow water control (3-12 m/∼10-39 ft). Using the same task, study 2 (N = 31) tested performance at the surface and at a range of depths underwater (1 m/3 ft; 11 m/36 ft; 20 m/66 ft; 30 m/98 ft; 40 m/131 ft). Study 1 revealed time production to be significantly longer in deep water compared to shallow water. In study 2 time production at the surface was not significantly different from that at 1 m, but productions at 11-40 m were significantly longer than at both 1 m and on the surface. Time productions between 11-40 m did not differ significantly. It was concluded that divers judge less time to have passed underwater than is objectively the case from a depth of 11 m, but that this effect does not deteriorate significantly once past 11 m. The cause of this distortion of time perception underwater was suggested to be the action of gas narcosis.Hobbs MB, Kneller W. Distortion of prospective time production underwater. Aerosp Med Hum Perform. 2017; 88(7):677-681.

Investigating the anticipatory nature of pattern perception in sport.

PubMed

Gorman, Adam D; Abernethy, Bruce; Farrow, Damian

2011-07-01

The aim of the present study was to examine the anticipatory nature of pattern perception in sport by using static and moving basketball patterns across three different display types. Participants of differing skill levels were included in order to determine whether the effects would be moderated by the knowledge and experience of the observer in the same manner reported previously for simple images. The results from a pattern recognition task showed that both expert and recreational participants were more likely to anticipate the next likely state of a pattern when it was presented as a moving video, but only the experts appeared to have the depth of understanding required to elicit the same anticipatory encoding for patterns presented as schematic images. The results extend those reported in previous research and provide further evidence of an anticipatory encoding in pattern perception for images containing complex, interrelated patterns.

[A gender perspective analysis of perception and practices in coronary disease in women from northern México].

PubMed

Juárez-Herrera Y Cairo, Lucero Aída; Castro-Vásquez, María Del Carmen; Ruiz-Cantero, María Teresa

2016-08-01

To analyze the perception of coronary risk and health care practices in a group of Mexican women, from a gendered perspective. Mixed methods: survey of 140 women; nine in-depth interviews to women with coronary disease; eight semi-structured interviews to physicians. proportions contrast for quantitative data; and procedures of grounded theory for qualitative information. More than 50% of women don't know their coronary risk and how to reduce it. Despite having information about heart disease, vulnerable women with chest pain sought medical attendance less than non-vulnerable women (p=0.0l); and are blamed by physicians. Women consider they lack sufficient information about how to reduce the risk of coronary disease, and blame themselves when ill. There are vulnerability conditions in women that modulate a low perception of their being at risk, and the scarcity of health care practices.

Rise and fall: two sides of a coin of middle aged women's perceptions of reproductive: a qualitative study.

PubMed

Reyhani, Mitra; Kazemi, Ashraf; Keshvari, Mahrokh

2018-02-02

The present study was conducted to determine the perceptions of middle-aged women of reproductive changes. The present study was a qualitative research with a content analysis approach. The participants were 30 middle-aged women whose perceptions of reproductive changes had been collected on in-depth semi-structured interviews. The data were analyzed using the Graneheim and Lundman's inductive content analysis method. The main themes extracted from the data were a sense of "fall" and "the beginning of a new life cycle." A feeling of fall was formed from the subthemes "deterioration of youth," "the dusk of femininity," and "fade-out of the gender roles." The theme "beginning of a new life cycle" was formed from the subthemes of "acceptance," "sophistication," and "maturity." Middle-aged women had a wide range of emotions experienced from the reproductive changes ranging from a feeling of decline to that of excellence and rise.

Exploring perceptions of HIV risk and health service access among Zimbabwean migrant women in Johannesburg: a gap in health policy in South Africa?

PubMed

Munyewende, Pascalia; Rispel, Laetitia C; Harris, Bronwyn; Chersich, Matthew

2011-01-01

We present qualitative data from a 2005 exploratory study, recently published studies, and an analysis of the Department of Health's strategic plan to highlight the need for a broader policy debate on health-care access for migrants in South Africa. We conducted in-depth interviews with 15 Zimbabwean women living in inner-city Johannesburg to document the special characteristics of this group of migrants, enquiring about their perceptions of HIV risk, and experiences of health services in South Africa. We identified access barriers, namely perceptions of relatively low HIV risk, severely constrained financial circumstances, uncertain legal status, and experiences of unresponsive health workers. We recommend that migrant-health rights be placed on South Africa's policy agenda, migrants be included in HIV prevention programs and that health workers be sensitized to the needs of migrants.

Cultural differences in room size perception

PubMed Central

Bülthoff, Heinrich H.; de la Rosa, Stephan; Dodds, Trevor J.

2017-01-01

Cultural differences in spatial perception have been little investigated, which gives rise to the impression that spatial cognitive processes might be universal. Contrary to this idea, we demonstrate cultural differences in spatial volume perception of computer generated rooms between Germans and South Koreans. We used a psychophysical task in which participants had to judge whether a rectangular room was larger or smaller than a square room of reference. We systematically varied the room rectangularity (depth to width aspect ratio) and the viewpoint (middle of the short wall vs. long wall) from which the room was viewed. South Koreans were significantly less biased by room rectangularity and viewpoint than their German counterparts. These results are in line with previous notions of general cognitive processing strategies being more context dependent in East Asian societies than Western ones. We point to the necessity of considering culturally-specific cognitive processing strategies in visual spatial cognition research. PMID:28426729

Understanding Taiwanese children's perceptions of peace and strategies to make peace: a social and cultural perspective.

PubMed

Deng, Liang-Yu F; Shih, Yi-Ling

2009-12-01

This exploratory study described Taiwanese children's perceptions of peace and what they think children can do to make peace. In-depth interviews were conducted with 60 Taiwanese children ages 4 to 18 years. The most predominant themes for the perceptions of peace were what peace is not, prosocial behaviors, positive emotions, and positive evaluations of peace. Approximately half of the children (48%) provided specific strategies for making peace. The suggested strategies generally were based on the child's immediate environment, such as "don't fight" "don't argue," and specific prosocial behaviors. 52% of children either said, "I don't know" when asked what children can do to make peace, or did not feel empowered to make peace. The initial findings were interpreted in terms of sociocultural issues, such as cultural heritage and upbringing, as well as within a political context.

Gender difference in the health risk perception of radiation from Fukushima in Japan: the role of hegemonic masculinity.

PubMed

Morioka, Rika

2014-04-01

This paper presents the preliminary findings of gender difference in the perception of radiation risk in the aftermath of the Fukushima nuclear disaster in Japan. In-depth interviews were conducted with the residents of Fukushima and other parts of Japan in November 2011 and July 2012. Compared to mothers, fathers in general expressed less concern for radiation. Fathers prioritized their responsibilities as the breadwinner for their families and saw radiation risk as a threat to economic stability and masculine identity. As a result, mothers' health concerns were dismissed, and they were prevented from taking preventive actions. The social norms in the dominant institutions such as corporations and the government influenced men's perception of radiation risk. The findings illustrate the importance of sociocultural context in which meanings of health risk are constructed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Assisted therapy with dogs in pediatric oncology: relatives' and nurses' perceptions.

PubMed

Moreira, Rebeca Lima; Gubert, Fabiane do Amaral; Sabino, Leidiane Minervina Moraes de; Benevides, Jéssica Lima; Tomé, Marcela Ariadne Braga Gomes; Martins, Mariana Cavalcante; Brito, Mychelangela de Assis

2016-01-01

to understand the perception of nursing staff professionals and legal guardians of children and adolescents with cancer regarding Assisted Therapy with dogs. qualitative study based on participant observation conducted with 16 participants in a reference hospital of child cancer. We applied an in-depth interview and interpreted the data according to a content analysis technique. the practice is admittedly beneficial to participants despite the fact they do not understand its true objectives and therapeutic applications. Participants only associate it with something distracting and entertaining without realizing the occurrence of a more complex process behind it, which comprises changes besides the emotional ones (more easily perceived). the perceptions of participants reinforce recommendations that can be applied in the hospital environment, also showing that the therapy in question can become an effective technology to promote the health of children and adolescents with cancer.

Singapore nursing students' perceptions and attitudes about spirituality and spiritual care in practice: a qualitative study.

PubMed

Tiew, Lay Hwa; Drury, Vicki

2012-09-01

This exploratory study investigated nursing students' perceptions and attitudes about spirituality and spiritual care in practice. A qualitative interpretative approach was used to investigate the research question. In-depth interviews were conducted with 16 final-year preregistration nursing students from 3 different educational institutions offering a degree or diploma program in Singapore. Data were analyzed using the Miles and Huberman's method of thematic analysis. Thematic analysis identified three themes: (a) students' perceptions of spirituality, (b) spiritual care, and (c) factors influencing spiritual care in practice. The study informed that though young, spirituality matters to the nursing students. Accordingly, nursing is perceived to play an integral role in spiritual care. Enabling factors need to be systematically addressed both in the education and practice arenas before the perennial issue of disconnect between development and implementation of spirituality in practice can be bridged.

Expectation affects verbal judgments but not reaches to visually perceived egocentric distances.

PubMed

Pagano, Christopher C; Isenhower, Robert W

2008-04-01

Two response measures for reporting visually perceived egocentric distances-verbal judgments and blind manual reaches-were compared using a within-trial methodology. The expected range of possible target distances was manipulated by instructing the subjects that the targets would be between .50 and 1.00 of their maximum arm reach in one session and between .25 and .90 in another session. The actual range of target distances was always .50-.90. Verbal responses varied as a function of the range of expected distances, whereas simultaneous reaches remained unaffected. These results suggest that verbal responses are subject to a cognitive influence that does not affect actions. It is suggested that action responses are indicative of absolute perception, whereas cognitive responses may reflect only relative perception. The results also indicate that the dependant variable utilized for the study of depth perception will influence the obtained results.

Cortical visual dysfunction in children: a clinical study.

PubMed

Dutton, G; Ballantyne, J; Boyd, G; Bradnam, M; Day, R; McCulloch, D; Mackie, R; Phillips, S; Saunders, K

1996-01-01

Damage to the cerebral cortex was responsible for impairment in vision in 90 of 130 consecutive children referred to the Vision Assessment Clinic in Glasgow. Cortical blindness was seen in 16 children. Only 2 were mobile, but both showed evidence of navigational blind-sight. Cortical visual impairment, in which it was possible to estimate visual acuity but generalised severe brain damage precluded estimation of cognitive visual function, was observed in 9 children. Complex disorders of cognitive vision were seen in 20 children. These could be divided into five categories and involved impairment of: (1) recognition, (2) orientation, (3) depth perception, (4) perception of movement and (5) simultaneous perception. These disorders were observed in a variety of combinations. The remaining children showed evidence of reduced visual acuity and/ or visual field loss, but without detectable disorders of congnitive visual function. Early recognition of disorders of cognitive vision is required if active training and remediation are to be implemented.

Benefits and Barriers of Pediatric Healthcare Providers toward Using Social Media in Asthma Care

ERIC Educational Resources Information Center

Martinasek, Mary P.; Panzera, Anthony D.; Schneider, Tali; Lindenberger, James H.; Bryant, Carol A.; McDermott, Robert J.; Couluris, Marisa

2011-01-01

Background: Adolescents with asthma are the least compliant age group for asthma management. Purpose: The purpose of this study was to explore attitudes, beliefs and perceptions of two pediatric physician groups towards using social media technology (SMT) to improve asthma management in adolescents. Methods: We employed in-depth interviews and a…

Promoting Peaceful Coexistence in Conflict-Ridden Cyprus: Teachers' Difficulties and Emotions towards a New Policy Initiative

ERIC Educational Resources Information Center

Zembylas, Michalinos; Charalambous, Constadina; Charalambous, Panayiota; Kendeou, Panayiota

2011-01-01

The present paper looks at teachers' perceptions of difficulties and emotions about a recent policy initiative in the Greek-Cypriot educational system to promote peaceful coexistence. This policy initiative by the government sparked strong emotional reactions. This paper provides an in-depth understanding of the intersection between tensions at…

Toward a Relational Perspective on Young Black and Latino Males: The Contextual Patterns of Disclosure as Coping

ERIC Educational Resources Information Center

Knight, David J.

2014-01-01

In this article, David J. Knight investigates where and when Black and Latino male adolescents engage in self-disclosure--sharing their emotions, thoughts, and social perceptions--with their peers. Building from asset-based research and ecological theories of development, Knight analyzes in-depth interviews and finds that these adolescents may…

Her Body Speaks: The Experience of Dance Therapy for Women Survivors of Child Sexual Abuse.

ERIC Educational Resources Information Center

Mills, Letty J.; Daniluk, Judith C.

2002-01-01

This qualitative, phenomenological study explores the experiences of dance therapy for 5 women who had been sexually abused as children. Using in-depth, largely unstructured interviews, the women reflect on their dance therapy experiences: and on their perceptions of the role of these experiences in their psychological healing. (Contains 46…

Head Start Administrator and Teacher Perceptions of Parental Influence on Preschool Children's Nutrition Education

ERIC Educational Resources Information Center

Stage, Virginia C.; Wilkerson, Kristi; Hegde, Archana; Lisson, Sarah; Babatunde, Oyinlola Toyin; Goodell, L. Suzanne

2018-01-01

Parents play a significant role in molding their children's nutrition knowledge and behavior. The purpose of the present study was to explore parental influence on preschooler's nutrition education from the perspectives of North Carolina-based Head Start coordinators and teachers. Investigators conducted 63 in-depth, structured interviews with…

Automated Creation of Labeled Pointcloud Datasets in Support of Machine-Learning Based Perception

DTIC Science & Technology

2017-12-01

computationally intensive 3D vector math and took more than ten seconds to segment a single LIDAR frame from the HDL-32e with the Dell XPS15 9650’s Intel...Core i7 CPU. Depth Clustering avoids the computationally intensive 3D vector math of Euclidean Clustering-based DON segmentation and, instead

The Effect of Interocular Contrast and Ocular Dominance on the Perception of Motion-in-Depth in 3-D Displays

DTIC Science & Technology

1981-08-01

Sokolov, 1911), by a plate containing a series of slits (Kanolt, 1918), or by lenticular sheets (Ives, 1930). A recently developed autostereoscopic...dioptic power and orientation were inserted in the stimulus deflector to correct the observer’s astigmatism . Spherical error, if 13 OBSERVER’S I

The Politics of Resistance to Workplace Cultural Diversity Education for Health Service Providers: An Australian Study

ERIC Educational Resources Information Center

Johnstone, Megan-Jane; Kanitsaki, Olga

2008-01-01

This qualitative study has as its focus an exploration of health service providers' perceptions and experiences of the processes and implications of delivering workplace cultural diversity education for staff. Data were obtained from conducting in-depth individual and focus group interviews with a purposeful sample of 137 healthcare professionals,…

Informal Music Making in Studio Music Instruction: A Canadian Case Study

ERIC Educational Resources Information Center

Brook, Julia; Upitis, Rena; Varela, Wynnpaul

2017-01-01

The purpose of this study was to gain an in-depth understanding of how one classically trained musician adapted his pedagogical practices to accommodate the needs and interests of his students. A case-study methodology was employed to explore the perceptions and practices of this teacher, and data were collected over a two-year period through…

Educational Applications of Vision Therapy: A Pilot Study on Children with Autism.

ERIC Educational Resources Information Center

Lovelace, Kelly; Rhodes, Heidi; Chambliss, Catherine

This report discusses the outcomes of a study that explored the feasibility of using vision therapy (VT) as part of an interdisciplinary approach to the education of children with autism. Traditional research on VT has explored its usefulness in helping patients to use both eyes together, improve depth perception, and enhance visual acuity.…

Multicultural Competence: A Literature Review Supporting Focused Training for Preservice Teachers Teaching Diverse Students

ERIC Educational Resources Information Center

Lehman, Cheryl L.

2017-01-01

This paper focuses on an in depth literature review based on preservice teachers perceptions of their multicultural competence in teaching diverse students. More specifically, the literature review was framed around findings from a study looking at the gap between increased diversity of students and the level of multicultural competence of…

Japanese Women's Perceptions of Intimate Partner Violence (IPV)

ERIC Educational Resources Information Center

Nagae, Miyoko; Dancy, Barbara L.

2010-01-01

Intimate partner violence (IPV) is a problem in Japan. The purpose is to describe IPV as perceived by a purposive sample of 11 Japanese adult females who were in a heterosexual marriage at the time of IPV. We used a cross-sectional, retroactive, qualitative description research design with individual, fact-to-face in depth interviews. At the time…

Inclusion and Homophily: An Argument about Participatory Decision-Making and Democratic School Management

ERIC Educational Resources Information Center

Koutsouris, George

2014-01-01

This paper reports findings from a study about school staff's perceptions of the preferences for social interaction that young people have with similar and different others. This tension was explored empirically using scenarios of moral dilemmas to conduct in-depth semi-structured interviews with school staff from special and mainstream secondary…

Implementation of School Choice Policy: Interpretation and Response by Parents of Students with Special Educational Needs.

ERIC Educational Resources Information Center

Bagley, Carl; Woods, Philip A.; Woods, Glenys

2001-01-01

Provides empirically based insights into preferences, perceptions, and responses of parents of students with special education needs to the 1990s restructured school system in England. Uses analyses of quantitative/qualitative data generated by a large-scale research study on school choice. Reveals depth and range of problems encountered by these…

Making Sense of Social Justice in Education: Jewish and Arab Leaders' Perspectives in Israel

ERIC Educational Resources Information Center

Arar, Khalid Husny; Oplatka, Izhar

2016-01-01

The research aimed to understand the way in which high school principals' perceptions of social justice (SJ) are implemented in their daily educational work. A qualitative study employed in-depth semi-structured interviews to collect the narratives of two high school principals in Israel--one Arab-Muslim and one Jewish. The interview transcripts…

"School within a School": Examining Implementation Barriers in a Spanish/English Transitional Bilingual Education Program

ERIC Educational Resources Information Center

DeNicolo, Christina Passos

2016-01-01

This article explores the ways that general education and bilingual teachers make sense of a Spanish/English transitional bilingual program housed at one elementary school in a Midwestern school district. An in-depth examination of perceptions and attitudes unmasks key factors regarding the implementation and interpretation of bilingual programs…

Perception of Auditory-Visual Distance Relations by 5-Month-Old Infants.

ERIC Educational Resources Information Center

Pickens, Jeffrey

1994-01-01

Sixty-four infants viewed side-by-side videotapes of toy trains (in four visual conditions) and listened to sounds at increasing or decreasing amplitude designed to match one of the videos. Results suggested that five-month olds were sensitive to auditory-visual distance relations and that change in size was an important visual depth cue. (MDM)

"Your Brain Becomes a Rainbow": Perceptions and Traits of 4th-Graders in a School-Based Mindfulness Intervention

ERIC Educational Resources Information Center

Keller, Julia; Ruthruff, Eric; Keller, Patrick; Hoy, Robert; Gaspelin, Nicholas; Bertolini, Katherine

2017-01-01

Although mindfulness, or the self-regulation of attention, has been found beneficial in reducing teacher stress and burnout and in increasing students' cognitive and emotional regulatory skills, no study has explored students' attitudes toward meditation practices in depth. This mixed-methods study reports results from a randomized, controlled…

Meaningful Messages: Adults in the Lower Mississippi Delta Provide Cultural Insight into Strategies for Promoting the MyPyramid

ERIC Educational Resources Information Center

Zoellner, Jamie; Bounds, Wendy; Connell, Carol; Yadrick, Kathy; Crook, LaShaundrea

2010-01-01

Objective: To explore cultural perceptions of the MyPyramid key messages and identify factors that may impact adoption of these recommendations. Methods: Systematic content analysis of transcripts from in-depth, structured interviews with 23 adults, primarily African American females, residing in the Lower Mississippi Delta. Results: When asked to…

Job Loss at Mid-Life: Managers and Executives Face the "New Risk Economy"

ERIC Educational Resources Information Center

Mendenhall, Ruby; Kalil, Ariel; Spindel, Laurel J.; Hart, Cassandra M. D.

2008-01-01

We use a life course framework to examine how the "new risk economy" has left middle-age professionals, managers and executives more vulnerable to job loss and unemployment despite high levels of human capital. Using in-depth qualitative data from 77 recently-unemployed white-collar workers, we examine perceptions of macro-economic…

Intonation in Neurogenic Foreign Accent Syndrome

ERIC Educational Resources Information Center

Kuschmann, Anja; Lowit, Anja; Miller, Nick; Mennen, Ineke

2012-01-01

Foreign accent syndrome (FAS) is a motor speech disorder in which changes to segmental as well as suprasegmental aspects lead to the perception of a foreign accent in speech. This paper focuses on one suprasegmental aspect, namely that of intonation. It provides an in-depth analysis of the intonation system of four speakers with FAS with the aim…

Diversifying California's Community College Leadership: What's Race Got to Do with It? A Qualitative Multiple Case Study

ERIC Educational Resources Information Center

Chochezi, Victoire S.

2013-01-01

This qualitative multiple case study examined diversity perceptions of California community college senior leaders and sought to provide insights into how a senior leader's view of diversity concepts influences their actions in succession planning and selection of leaders and faculty. An in-depth qualitative analysis of participant interviews and…

Community College Developmental Education Services: Perspectives of Spanish-Speaking Latino Early Childhood Educators

ERIC Educational Resources Information Center

Eberly, John E.

2018-01-01

The purpose of this single-case study was to understand the perceptions of Latino Spanish-speaking English learners on the efficacy of developmental education services at a Western U.S. community college. The primary data collection method was in-depth individual interviews of a purposeful sample of nine successful students. Findings indicated…

Effective Parental Involvement in Education: Experiences and Perceptions of Turkish Teachers from Private Schools

ERIC Educational Resources Information Center

Gokturk, Soheyda; Dinckal, Selin

2018-01-01

Parental involvement has been associated with numerous student benefits. However, related literature reveals that neither parents nor teachers are content with the scope and depth of parental involvement in schools. This may be partly due to differential understandings that both sides have on the concept of parental involvement. In this study,…

Students' Perceptions of Autonomous Out-of-Class Learning through the Use of Computers

ERIC Educational Resources Information Center

Liu, Xianghu

2014-01-01

This study investigates the attitudes towards, and practices of, computer-assisted autonomous learning in learning English of 160 students from three different higher education institutions in China. To do this, a questionnaire was completed by 160 participants, and follow-up in-depth interviews were undertaken with six participants and six of…

Improving Scores on Computerized Reading Assessments: The Effects of Colored Overlay Use

ERIC Educational Resources Information Center

Adams, Tracy A.

2012-01-01

Visual stress is a perceptual dysfunction that appears to affect how information is processed as it passes from the eyes to the brain. Photophobia, visual resolution, restricted focus, sustaining focus, and depth perception are all components of visual stress. Because visual stress affects what is perceived by the eye, students with this disorder…

Challenges of Blended E-Learning Tools in Mathematics: Students' Perspectives University of Uyo

ERIC Educational Resources Information Center

Umoh, Joseph B.; Akpan, Ekemini T.

2014-01-01

An in-depth knowledge of pedagogical approaches can help improve the formulation of effective and efficient pedagogy, tools and technology to support and enhance the teaching and learning of Mathematics in higher institutions. This study investigated students' perceptions of the challenges of blended e-learning tools in the teaching and learning…

Adolescent Girls' Perceptions of Smoking Risk and Protective Factors: Implications for Message Design

ERIC Educational Resources Information Center

Curbow, Barbara; Bowie, Janice; Binko, JoAnn; Smith, Stephanie; Dreyling, Erin; McDonnell, Karen A.

2007-01-01

Using a snowball technique, in-depth interviews were conducted with 108 girls emanating from seven demographically dissimilar social networks. Girls were asked to classify 58 items as either a risk or protective factor for smoking initiation and then to assign an importance weighting to each. All items except one (worries about her weight) were…

"I Want to Do the Right Thing but What Is It?": White Teachers' Experiences with African American Students

ERIC Educational Resources Information Center

Henfield, Malik S.; Washington, Ahmad R.

2012-01-01

This qualitative study examines 26 White middle school teachers' perceptions of their experiences in a predominantly White middle school with a growing African American student population. Utilizing in-depth focus group interviews, teachers elaborated on their experiences with navigating racial, ethnic and cultural boundaries as they attempted to…

Qualitative Analysis of Student Perceptions of E-Portfolios in a Teacher Education Program

ERIC Educational Resources Information Center

Parker, Michele; Ndoye, Abdou; Ritzhaupt, Albert D.

2012-01-01

In the last decade, e-portfolios have moved to the forefront of teacher preparation programs across the United States. With its widespread use, faculty and administrators need to understand teacher candidates' perspectives to meet their needs. In the present study, the researchers gathered in-depth information from 244 students who were required…

Barriers and Supports for Continuing in Mathematics and Science: Gender and Educational Level Differences

ERIC Educational Resources Information Center

Fouad, Nadya A.; Hackett, Gail; Smith, Philip L.; Kantamneni, Neeta; Fitzpatrick, Mary; Haag, Susan; Spencer, Dee

2010-01-01

This article presents three studies that provide an in-depth examination of STEM-related supports and barriers. These studies constructed an instrument to identify male and female perceptions of the barriers and supports for pursuing coursework and/or careers in mathematics and sciences domains; to pilot test and refine that instrument; and then…

The Hurdles to Being World Class: Narrative Analysis of the World-Class University Project in Korea

ERIC Educational Resources Information Center

Jang, Deok-Ho; Ryu, Kiung; Yi, Pilnam; Craig, Daniel A.

2016-01-01

This study examines the Korean Government's policy scheme of setting up the World-Class University (WCU) Project by investigating the perceptions of major actors, including WCU scholars and government officials. In-depth interviews were held with 18 WCU scholars and three government officials. Our findings suggest that the limits of the…

Parents' Mobile Technology Adoption Influences on Elementary Children's Use

ERIC Educational Resources Information Center

Eutsler, Lauren

2018-01-01

Purpose: With a high rate of mobile technology ownership in the home, it is unknown how parents' behavioral intention influences mobile technology adoption and children's informal use to support reading. The purpose of this paper is to identify 120 parents' intentions to adopt mobile technology and gather in-depth perceptions about mobile…

A Phenomenological Study of African American Women College and University Presidents: Their Career Paths, Challenges and Barriers

ERIC Educational Resources Information Center

Jones, Tavis Alicia

2013-01-01

The purpose of this study was to address the career paths, challenges, and barriers of African American women college or university presidents. In addition, the expectation was to identify the "perceptions" of barriers to acquire the position of president. Using a phenomenological paradigm of inquiry, in-depth semi-structured personal…

Reflections of College English Majors' Cultural Perceptions on Learning English in Taiwan

ERIC Educational Resources Information Center

Cheng, Ching-Mei

2013-01-01

This study was conducted with the participation of nine English as a Foreign Language (EFL) students and two EFL teachers of the Department of Applied English at an institute of technology in central Taiwan. Based on in-depth interviews with the students and teachers, the findings suggest that the participating students' perspectives of culture…

Stereo-motion cooperation and the use of motion disparity in the visual perception of 3-D structure.

PubMed

Cornilleau-Pérès, V; Droulez, J

1993-08-01

When an observer views a moving scene binocularly, both motion parallax and binocular disparity provide depth information. In Experiments 1A-1C, we measured sensitivity to surface curvature when these depth cues were available either individually or simultaneously. When the depth cues yielded comparable sensitivity to surface curvature, we found that curvature detection was easier with the cues present simultaneously, rather than individually. For 2 of the 6 subjects, this effect was stronger when the component of frontal translation of the surface was vertical, rather than horizontal. No such anisotropy was found for the 4 other subjects. If a moving object is observed binocularly, the patterns of optic flow are different on the left and right retinae. We have suggested elsewhere (Cornilleau-Pérès & Droulez, in press) that this motion disparity might be used as a visual cue for the perception of a 3-D structure. Our model consisted in deriving binocular disparity from the left and right distributions of vertical velocities, rather than from luminous intensities, as has been done in classical studies on stereoscopic vision. The model led to some predictions concerning the detection of surface curvature from motion disparity in the presence or absence of intensity-based disparity (classically termed binocular disparity). In a second set of experiments, we attempted to test these predictions, and we failed to validate our theoretical scheme from a physiological point of view.

Pocket-depths-related effectiveness of an intrapocket anaesthesia gel in periodontal maintenance patients.

PubMed

Derman, S H M; Lowden, C E; Kaus, P; Noack, M J

2014-05-01

The aim of this study was to determine the impact of the pocket depth on the effectiveness of an intrapocket anaesthesia gel during SRP in periodontal maintenance patients. Effectiveness was measured by pain levels during SRP via visual analogue scale (VAS) and verbal rating scale (VRS). Secondary endpoint was the evaluation of patients' preferred choice of anaesthesia for SRP. A total of 638 patients undergoing the periodontal maintenance programme and with the need for SRP participated in this observational study. After SRP, patients filled in questionnaires to record pain levels experienced and anaesthesia preference for future use. Mann-Whitney U-test was used to analyse intergroup difference in pain perception and anaesthesia choice. Overall, increasing pocket depths were accompanied by higher pain levels, irrespective of maximum or commonest pocket depths (P < 0.05). For SRP procedures, patients definitely prefer the anaesthesia gel (72.4%). In this study, an effectiveness of local anaesthesia gel (lidocaine/prilocaine) related to pocket depths was found in periodontal maintenance patients during SRP. Increasing pocket depths were accompanied by increasing procedural pain levels. Nevertheless, the anaesthesia gel is well accepted and in the majority of cases was found to be the preferred option for future SRP treatments. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Perceptions of Equipoise, Risk-Benefit Ratios, and "Otherwise Healthy Volunteers" in the Context of Early-Phase HIV Cure Research in the United States: A Qualitative Inquiry.

PubMed

Dubé, Karine; Dee, Lynda; Evans, David; Sylla, Laurie; Taylor, Jeff; Brown, Brandon; Miller, Veronica; Corneli, Amy; Skinner, Asheley; Greene, Sandra B; Tucker, Joseph D; Rennie, Stuart

2018-02-01

Early-phase HIV cure research is conducted against a background of highly effective antiretroviral therapy, and involves risky interventions in individuals who enjoy an almost normal life expectancy. To explore perceptions of three ethical topics in the context of HIV cure research-(a) equipoise, (b) risk-benefit ratios, and (c) "otherwise healthy volunteers"-we conducted 36 in-depth interviews (IDIs) with three groups of purposively selected key informants: clinician-researchers ( n = 11), policy-makers and bioethicists ( n = 13), and people living with HIV (PLWHIV; n = 12). Our analysis revealed variability in perceptions of equipoise. Second, most key informants believed there was no clear measure of risk-benefit ratios in HIV cure research, due in part to the complexity of weighing (sometimes unknown) risks to participants and (sometimes speculative) benefits to science and society. Third, most clinician-researchers and policy-makers/bioethicists viewed potential HIV cure study participants as "otherwise healthy volunteers," but this perception was not shared among PLWHIV in our study.

Can I cut it? Medical students' perceptions of surgeons and surgical careers.

PubMed

Hill, Elspeth J R; Bowman, Katherine A; Stalmeijer, Renée E; Solomon, Yvette; Dornan, Tim

2014-11-01

Recent years have seen a significant drop in applications to surgical residencies. Existing research has yet to explain how medical students make career decisions. This qualitative study explores students' perceptions of surgery and surgeons, and the influence of stereotypes on career decisions. Exploratory questionnaires captured students' perceptions of surgeons and surgery. Questionnaire data informed individual interviews, exploring students' perceptions in depth. Rigorous qualitative interrogation of interviews identified emergent themes from which a cohesive analysis was synthesized. Respondents held uniform stereotypes of surgeons as self-confident and intimidating; surgery was competitive, masculine, and required sacrifice. To succeed in surgery, students felt they must fit these stereotypes, excluding those unwilling, or who felt unable, to conform. Deviating from the stereotypes required displaying such characteristics to a level exceptional even for surgery; consequently, surgery was neither an attractive nor realistic career option. Strong stereotypes of surgery deterred students from a surgical career. As a field, surgery must actively engage medical students to encourage participation and dispel negative stereotypes that are damaging recruitment into surgery. Copyright © 2014 Elsevier Inc. All rights reserved.

A simple photometric factor in perceived depth order of bistable transparency patterns.

PubMed

Fukiage, Taiki; Oishi, Takeshi; Ikeuchi, Katsushi

2014-05-05

Previous studies on perceptual transparency defined the photometric condition in which perceived depth ordering between two surfaces becomes ambiguous. Even under this bistable transparency condition, it is known that depth-order perceptions are often biased toward one specific interpretation (Beck, Prazdny, & Ivry, 1984; Delogu, Fedorov, Belardinelli, & van Leeuwen, 2010; Kitaoka, 2005; Oyama & Nakahara, 1960). In this study, we examined what determines the perceived depth ordering for bistable transparency patterns using stimuli that simulated two partially overlapping disks resulting in four regions: a (background), b (portion of right disk), p (portion of left disk), and q (shared region). In contrast to the previous theory that proposed contributions of contrast against the background region (i.e., contrast at contour b/a and contrast at contour p/a) to perceived depth order in bistable transparency patterns, the present study demonstrated that contrast against the background region has little influence on perceived depth order compared with contrast against the shared region (i.e., contrast at contour b/q and contrast at contour p/q). In addition, we found that the perceived depth ordering is well predicted by a simpler model that takes into consideration only relative size of lightness difference against the shared region. Specifically, the probability that the left disk is perceived as being in front is proportional to (|b - q| - |p - q|) / (|b - q| + |p - q|) calculated based on lightness.

Evaluating motion parallax and stereopsis as depth cues for autostereoscopic displays

NASA Astrophysics Data System (ADS)

Braun, Marius; Leiner, Ulrich; Ruschin, Detlef

2011-03-01

The perception of space in the real world is based on multifaceted depth cues, most of them monocular, some binocular. Developing 3D-displays raises the question, which of these depth cues are predominant and should be simulated by computational means in such a panel. Beyond the cues based on image content, such as shadows or patterns, Stereopsis and depth from motion parallax are the most significant mechanisms supporting observers with depth information. We set up a carefully designed test situation, widely excluding undesired other distance hints. Thereafter we conducted a user test to find out, which of these two depth cues is more relevant and whether a combination of both would increase accuracy in a depth estimation task. The trials were conducting utilizing our autostereoscopic "Free2C"-displays, which are capable to detect the user eye position and steer the image lobes dynamically into that direction. At the same time, eye position was used to update the virtual camera's location and thereby offering motion parallax to the observer. As far as we know, this was the first time that such a test has been conducted using an autosteresocopic display without any assistive technologies. Our results showed, in accordance with prior experiments, that both cues are effective, however Stereopsis is by order of magnitude more relevant. Combining both cues improved the precision of distance estimation by another 30-40%.

Sampling artifacts in perspective and stereo displays

NASA Astrophysics Data System (ADS)

Pfautz, Jonathan D.

2001-06-01

The addition of stereo cues to perspective displays is generally expected to improve the perception of depth. However, the display's pixel array samples both perspective and stereo depth cues, introducing inaccuracies and inconsistencies into the representation of an object's depth. The position, size and disparity of an object will be inaccurately presented and size and disparity will be inconsistently presented across depth. These inconsistencies can cause the left and right edges of an object to appear at different stereo depths. This paper describes how these inconsistencies result in conflicts between stereo and perspective depth information. A relative depth judgement task was used to explore these conflicts. Subjects viewed two objects and reported which appeared closer. Three conflicts resulting from inconsistencies caused by sampling were examined: (1) Perspective size and location versus stereo disparity. (2) Perspective size versus perspective location and stereo disparity. (3) Left and right edge disparity versus perspective size and location. In the first two cases, subjects achieved near-perfect accuracy when perspective and disparity cues were complementary. When size and disparity were inconsistent and thus in conflict, stereo dominated perspective. Inconsistency between the disparities of the horizontal edges of an object confused the subjects, even when complementary perspective and stereo information was provided. Since stereo was the dominant cue and was ambiguous across the object, this led to significantly reduced accuracy. Edge inconsistencies also led to more complaints about visual fatigue and discomfort.

A note on drillhole depths required for reliable heat flow determinations

USGS Publications Warehouse

Chapman, D.S.; Howell, J.; Sass, J.H.

1984-01-01

In general, there is a limiting depth in a drillhole above which the reliability of a single determination of heat flow decreases rapidly with decreasing depth and below which the statistical uncertainty of a heat flow determination does not change perceptibly with increasing depth. This feature has been established empirically for a test case comprising a group of twelve heat flow sites in the Republic of Zambia. The technique consists of constructing heat flow versus depth curves for individual sites by progressively discarding data from the lower part of the hole and recomputing heat flow from the remaining data. For the Zambian test case, the curves converge towards a uniform value of 67 ?? 3 mW m-2 when all available data are used, but values of heat flow calculated for shallow(< 100 m) parts of the same holes range from 45 to 95 mW m-2. The heat flow versus depth curves are enclosed by a perturbation envelope which has an amplitude of 40 mW m-2 at the surface and decreases linearly to the noise level at 190 m. For the test region of Zambia a depth of 170 m is needed to guarantee a heat flow measurement within ?? 10% of the background regional value. It is reasonable to expect that this depth will be shallower in some regions and deeper in others. Features of heat flow perturbation envelopes can be used as quantitative reliability indices for heat flow studies. ?? 1984.

Kinder, gentler stereo

NASA Astrophysics Data System (ADS)

Siegel, Mel; Tobinaga, Yoshikazu; Akiya, Takeo

1999-05-01

Not only binocular perspective disparity, but also many secondary binocular and monocular sensory phenomena, contribute to the human sensation of depth. Binocular perspective disparity is notable as the strongest depth perception factor. However means for creating if artificially from flat image pairs are notorious for inducing physical and mental stresses, e.g., 'virtual reality sickness'. Aiming to deliver a less stressful 'kinder gentler stereo (KGS)', we systematically examine the secondary phenomena and their synergistic combination with each other and with binocular perspective disparity. By KGS we mean a stereo capture, rendering, and display paradigm without cue conflicts, without eyewear, without viewing zones, with negligible 'lock-in' time to perceive the image in depth, and with a normal appearance for stereo-deficient viewers. To achieve KGS we employ optical and digital image processing steps that introduce distortions contrary to strict 'geometrical correctness' of binocular perspective but which nevertheless result in increased stereoscopic viewing comfort. We particularly exploit the lower limits of interoccular separation, showing that unexpectedly small disparities stimulate accurate and pleasant depth sensations. Under these circumstances crosstalk is perceived as depth-of-focus rather than as ghosting. This suggests the possibility of radically new approaches to stereoview multiplexing that enable zoneless autostereoscopic display.

Replicating and extending Bourdon's (1902) experiment on motion parallax.

PubMed

Ono, Hiroshi; Lillakas, Linda; Kapoor, Anjani; Wong, Irene

2013-01-01

Bourdon conducted the first laboratory experiment on observer-produced motion parallax as a cue to depth. In three experiments, we replicated and extended Bourdon's experiment. In experiment 1, we reproduced his finding: when the two cues, motion parallax and relative height, were combined, accuracy of depth perception was high, and when the two cues were in conflict, accuracy was lower. In experiment 2, the relative height cue was replaced with relative retinal image size. As in experiment 1, when the two cues (motion parallax and relative retinal image size) were combined, accuracy was high, but when they were in conflict, it was lower. In experiment 3, the stimuli from experiments 1 and 2 were viewed monocularly with head movement and binocularly without head movement. In the binocular conditions, accuracy, certainty, and the extent of perceived depth were higher than in the monocular condition. In the conflict conditions, accuracy, certainty, and the extent of perceived depth were lower than in the no-conflict condition, but the extent of perceived motion was larger. These results are discussed in terms of recent findings about the effectiveness of motion parallax as a cue for depth.

Depth reversals in stereoscopic displays driven by apparent size

NASA Astrophysics Data System (ADS)

Sacher, Gunnar; Hayes, Amy; Thornton, Ian M.; Sereno, Margaret E.; Malony, Allen D.

1998-04-01

In visual scenes, depth information is derived from a variety of monocular and binocular cues. When in conflict, a monocular cue is sometimes able to override the binocular information. We examined the accuracy of relative depth judgments in orthographic, stereoscopic displays and found that perceived relative size can override binocular disparity as a depth cue in a situation where the relative size information is itself generated from disparity information, not from retinal size difference. A size discrimination task confirmed the assumption that disparity information was perceived and used to generate apparent size differences. The tendency for the apparent size cue to override disparity information can be modulated by varying the strength of the apparent size cue. In addition, an analysis of reaction times provides supporting evidence for this novel depth reversal effect. We believe that human perception must be regarded as an important component of stereoscopic applications. Hence, if applications are to be effective and accurate, it is necessary to take into account the richness and complexity of the human visual perceptual system that interacts with them. We discuss implications of this and similar research for human performance in virtual environments, the design of visual presentations for virtual worlds, and the design of visualization tools.

Streaming video-based 3D reconstruction method compatible with existing monoscopic and stereoscopic endoscopy systems

NASA Astrophysics Data System (ADS)

Bouma, Henri; van der Mark, Wannes; Eendebak, Pieter T.; Landsmeer, Sander H.; van Eekeren, Adam W. M.; ter Haar, Frank B.; Wieringa, F. Pieter; van Basten, Jean-Paul

2012-06-01

Compared to open surgery, minimal invasive surgery offers reduced trauma and faster recovery. However, lack of direct view limits space perception. Stereo-endoscopy improves depth perception, but is still restricted to the direct endoscopic field-of-view. We describe a novel technology that reconstructs 3D-panoramas from endoscopic video streams providing a much wider cumulative overview. The method is compatible with any endoscope. We demonstrate that it is possible to generate photorealistic 3D-environments from mono- and stereoscopic endoscopy. The resulting 3D-reconstructions can be directly applied in simulators and e-learning. Extended to real-time processing, the method looks promising for telesurgery or other remote vision-guided tasks.

The Role of Amodal Surface Completion in Stereoscopic Transparency

PubMed Central

Anderson, Barton L.; Schmid, Alexandra C.

2012-01-01

Previous work has shown that the visual system can decompose stereoscopic textures into percepts of inhomogeneous transparency. We investigate whether this form of layered image decomposition is shaped by constraints on amodal surface completion. We report a series of experiments that demonstrate that stereoscopic depth differences are easier to discriminate when the stereo images generate a coherent percept of surface color, than when images require amodally integrating a series of color changes into a coherent surface. Our results provide further evidence for the intimate link between the segmentation processes that occur in conditions of transparency and occlusion, and the interpolation processes involved in the formation of amodally completed surfaces. PMID:23060829

"You Must Know Where You Come From": South African Youths' Perceptions of Religion in Time of Social Change.

PubMed

Brittian, Aerika S; Lewin, Nina; Norris, Shane A

2013-11-01

This study examined South African youths' perceptions of religion during a period of social and economic transition. In-depth interviews were conducted with 55 Black South African youth (age 18) living in the Johannesburg-Soweto metropolitan area. Data were analyzed in a manner consistent with grounded theory methodology and structural coding. Beliefs about the function of religion were captured by the following themes: provides support, connection to the past, moral compass, promotes healthy development, and intersections between African traditional practices and Christian beliefs. Themes are discussed and directions for future research are presented. In addition, applications of the current research and implications for promoting youths' resilience are offered.

Striving to make a difference: health care worker experiences with intimate partner violence clients in Tanzania.

PubMed

Laisser, Rose M; Lugina, Helen I; Lindmark, Gunilla; Nystrom, Lennarth; Emmelin, Maria

2009-01-01

In this article we describe health care workers' (HCWs') experiences and perceptions of meeting clients exposed to intimate partner violence (IPV). Qualitative content analysis of in-depth interviews from 16 informants resulted in four main themes. The first, "internalizing women's suffering and powerlessness," describes HCWs' perceptions of violence, relating it to gender relations. The second, "caught between encouraging disclosure and lack of support tools," refers to views on possibilities for transparency and openness. The third, "Why bother? A struggle to manage with limited resources," illustrates the consequences of a heavy workload. Last; "striving to make a difference," emphasizes a desire to improve abilities to support clients and advocate for prevention.

First- and second-order processing in transient stereopsis.

PubMed

Edwards, M; Pope, D R; Schor, C M

2000-01-01

Large-field stimuli were used to investigate the interaction of first- and second-order pathways in transient-stereo processing. Stimuli consisted of sinewave modulations in either the mean luminance (first-order stimulus) or the contrast (second-order stimulus) of a dynamic-random-dot field. The main results of the present study are that: (1) Depth could be extracted with both the first-order and second-order stimuli; (2) Depth could be extracted from dichoptically mixed first- and second-order stimuli, however, the same stimuli, when presented as a motion sequence, did not result in a motion percept. Based upon these findings we conclude that the transient-stereo system processes both first- and second-order signals, and that these two signals are pooled prior to the extraction of transient depth. This finding of interaction between first- and second-order stereoscopic processing is different from the independence that has been found with the motion system.

VISIDEP™: visual image depth enhancement by parallax induction

NASA Astrophysics Data System (ADS)

Jones, Edwin R.; McLaurin, A. P.; Cathey, LeConte

1984-05-01

The usual descriptions of depth perception have traditionally required the simultaneous presentation of disparate views presented to separate eyes with the concomitant demand that the resulting binocular parallax be horizontally aligned. Our work suggests that the visual input information is compared in a short-term memory buffer which permits the brain to compute depth as it is normally perceived. However, the mechanism utilized is also capable of receiving and processing the stereographic information even when it is received monocularly or when identical inputs are simultaneously fed to both eyes. We have also found that the restriction to horizontally displaced images is not a necessary requirement and that improvement in image acceptability is achieved by the use of vertical parallax. Use of these ideas permit the presentation of three-dimensional scenes on flat screens in full color without the encumbrance of glasses or other viewing aids.

A Bourdieusian Analysis of the Participation of Polish Students in the Erasmus Programme: Cultural and Social Capital Perspectives

ERIC Educational Resources Information Center

Bótas, Paulo Charles Pimentel; Huisman, Jeroen

2013-01-01

In this paper we examine the perceptions of ERASMUS agents' of Polish students' participation in the EP. We provide a Bourdieusian analyse of the cultural and social capital acquisition of students based on the qualitative data, collected through semi-structured, in-depth interviews with Erasmus agents, of a European research project. We argue…

Teachers' Experience in Implementing Cooperative Learning in the Classrooms (Phenomenological Research at Junior High School Classrooms in Ponorogo, East Java, Indonesia)

ERIC Educational Resources Information Center

Harjali

2017-01-01

This study aimed to investigate the teachers' perception toward the implementation of cooperative learning in the classroom. The research applied a qualitative phenomenological design that used a purposeful sample of six teachers at Junior High School Classrooms in Ponorogo, East Java, Indonesia. Data collected via in-depth interviews, participant…

Computer Assisted Virtual Environment - CAVE

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

Erickson, Phillip; Podgorney, Robert; Weingartner,

Research at the Center for Advanced Energy Studies is taking on another dimension with a 3-D device known as a Computer Assisted Virtual Environment. The CAVE uses projection to display high-end computer graphics on three walls and the floor. By wearing 3-D glasses to create depth perception and holding a wand to move and rotate images, users can delve into data.

Divorce Is a Part of My Life . . . Resilience, Survival, and Vulnerability: Young Adults' Perception of the Implications of Parental Divorce

ERIC Educational Resources Information Center

Eldar-Avidan, Dorit; Haj-Yahia, Muhammad M.; Greenbaum, Charles W.

2009-01-01

A qualitative study among 22 young adults (20-25 years old) whose parents divorced during their childhood was conducted in Israel, using semi-structured, in-depth, open-ended interviews. Qualitative data analysis led to identification of three profiles, aiming at a grounded theoretical conceptualization. Three core themes were identified: the…

A Case Study of the Diversity Culture of an American University Athletic Department: Perceptions of Senior Level Administrators

ERIC Educational Resources Information Center

Singer, John N.; Cunningham, George B.

2012-01-01

The topic of diversity has received considerable attention from scholars who study sport within the context of higher education in the USA. But despite this interest in the topic, an in-depth focus on how college and university athletic departments effectively manage diversity is missing from the literature. Therefore, we conducted an intrinsic…

If You Require It, Will They Learn from It? Student Perceptions of an Independent Research Project

ERIC Educational Resources Information Center

Conner, Jerusha O.

2010-01-01

Although most teachers believe that "students should write at least one in-depth paper during high school," the independent research paper is disappearing from high school curricula in the face of two competing pressures: the need to prepare for high-stakes tests and student "senioritis." In many high schools, the senior year has become "a…

Exploring Pre-Service School Counselling Teachers' Learning Needs: Perceptions of Teacher Educators and Student-Teachers

ERIC Educational Resources Information Center

Yuan, Rui

2017-01-01

Drawing on the dual perspectives of teacher educators and student-teachers, this research explores the complex learning needs of pre-service school counselling teachers (SCTs) in China. Relying on data from in-depth interviews and relevant curriculum documents, the findings of the study demonstrate four critical needs of SCTs, namely, developing a…

Affirmative Consent: What Do College Student Leaders Think about "Yes Means Yes" as the Standard for Sexual Behavior?

ERIC Educational Resources Information Center

Curtis, Jena Nicols; Burnett, Susan

2017-01-01

Affirmative consent (AC) is becoming the standard for sexual behavior between students. However, little is known about how college students interpret and practice AC. We conducted in-depth, semistructured interviews with a purposeful sample of 31 undergraduate students to understand students' perceptions of AC and how it was practiced in their…

"The Bar Is Slightly Higher": The Perception of Racism in Teacher Education

ERIC Educational Resources Information Center

Basit, Tehmina N.; McNamara, Olwen; Roberts, Lorna; Carrington, Bruce; Maguire, Meg; Woodrow, Derek

2007-01-01

The education and training of teachers is an issue of national concern. In this paper we analyse the findings of an in-depth investigation, undertaken by means of semi structured interviews, of a group of minority ethnic teacher trainees who withdrew from Initial Teacher Training courses in England, and a smaller group of those who completed these…

Barriers to Academic Achievement for Foster Youth: The Story behind the Statistics

ERIC Educational Resources Information Center

Morton, Brenda M.

2015-01-01

The purpose of this qualitative research study was to explore the perceptions of former and current foster youth about the barriers they encountered during their K-12 education, and to learn how they overcame these obstacles and achieved academic success. The study included in-depth interviews of 11 participants, all of whom were current or former…

Critical Success Factors for an Effective Security Risk Management Program in an Organization: An Exploratory Case Study

ERIC Educational Resources Information Center

Zafar, Humayun

2010-01-01

This study investigates differences in perception between layers of management (executive, middle, and lower) and staff with regard to the influence of critical success factors (CSFs) on security risk management (SRM) effectiveness. This is an in-depth case study conducted at a Fortune 500 company. Rockart's (1979) CSF method is modified through…

The Impact of One-to-One Technology Programs on Student Acquisition of 21st-Century Skills

ERIC Educational Resources Information Center

McDowell, Joshua A.

2017-01-01

This qualitative phenomenological study was designed to gain an in-depth understanding of the perceptions of secondary public-school teachers of the impact that one-to-one technology programs have on student acquisition of 21st-century skills. 20 certified public school teachers were targeted using a purposeful sampling method, in 4 public school…

Qualitative Inquiry with Women in Poverty in Mexico City: Reflections on the Emotional Responses of a Research Team

ERIC Educational Resources Information Center

Martinez-Salgado, Carolina

2009-01-01

While conducting a qualitative inquiry involving in-depth interviews on the perceptions of health risks within a group of profoundly poor urban families in the southern part of Mexico City, Martinez-Salgado and her interdisciplinary team of women interviewers got involved in emotionally complex situations with the women participants in the study.…

Computer Assisted Virtual Environment - CAVE

ScienceCinema

Erickson, Phillip; Podgorney, Robert; Weingartner,

2018-05-30

Research at the Center for Advanced Energy Studies is taking on another dimension with a 3-D device known as a Computer Assisted Virtual Environment. The CAVE uses projection to display high-end computer graphics on three walls and the floor. By wearing 3-D glasses to create depth perception and holding a wand to move and rotate images, users can delve into data.

Transgender Identities and Gender Variance in Vocational Psychology: Recommendations for Practice, Social Advocacy, and Research

ERIC Educational Resources Information Center

O'Neil, Maya Elin; McWhirter, Ellen Hawley; Cerezo, Alison

2008-01-01

Effective practices for career counseling with gender variant individuals have yet to be identified for reasons that may include perceptions that the population is too small to warrant in-depth research, lack of funding for such efforts, and practitioners' lack of training and experience with transgender concerns. In this article, we describe the…

Peer Interaction, Cognitive Conflict, and Anxiety on a Grammar Awareness Course for Language Teachers

ERIC Educational Resources Information Center

Svalberg, Agneta Marie-Louise

2012-01-01

This study explored some MA students' perceptions of a Grammar Awareness course for language teachers. The aim was to understand how group tasks might help students build Grammar Awareness. Two cohorts of students were surveyed and interviewed. In this paper, the survey responses are discussed in some depth. While the first cohort was left to…

Contrasting Disclosure Practices and Experiences of School Support for Australian Adolescents with Cancer, Cystic Fibrosis and Anorexia Nervosa: Parent Perspectives

ERIC Educational Resources Information Center

Bowtell, Evelyn Cecile; Aroni, Rosalie; Green, Julie; Sawyer, Susan M.

2018-01-01

Schools in Australia are required to promote equitable access to education and provide support services to students with chronic health conditions (CHCs). This qualitative study was conducted to explore stakeholders' experiences and perceptions regarding school-based support. In-depth interviews were conducted with 38 parents of upper secondary…

Perceived Treatment Effectiveness of Family Therapy for Chinese Patients Suffering from Anorexia Nervosa: A Qualitative Inquiry

ERIC Educational Resources Information Center

Ma, Joyce L. C.; Lai, Kelly

2006-01-01

Although family therapy has become highly acceptable in the West, its applicability and acceptability for Chinese adolescents and young women with anorexia nervosa (AN) remains unknown. In this article, we report the results of a qualitative study using post-treatment in-depth interviews to understand the subjective perceptions of sufferers of AN…

Case Studies to Deepen Understanding and Enhance Classroom Management Skills in Preschool Teacher Training

ERIC Educational Resources Information Center

Tal, Clodie

2010-01-01

This article adds to the existing body of data that demonstrates how the use of in-depth case studies that include social episode analysis can deepen the teaching students' and researchers' understanding of the perceptions and skills needed for Classroom Management (CM). In this article, CM is defined as a meta-skill that integrates cognitive…

"In the Driver's Seat": Parent Perceptions of Choice in a Participant-Directed Medicaid Waiver Program for Young Children with Autism

ERIC Educational Resources Information Center

Timberlake, Maria T.; Leutz, Walter N.; Warfield, Marji Erickson; Chiri, Giuseppina

2014-01-01

This study investigated families' experience of choice within a participant-directed Medicaid waiver program for young children with autism. Fourteen parents or grandparents participated in in-depth interviews about their experience of choosing personnel, directing in-home services, and managing the $25,000 annual allocation. Key findings…

Hurting No-One Else's Body but Your Own: People with Intellectual Disability Who Self Injure in a Forensic Service

ERIC Educational Resources Information Center

Duperouzel, Helen; Fish, Rebecca

2010-01-01

Background: This paper details the experiences of nine people with mild/moderate intellectual disability who self injure; looking beyond the clinical presentations in an attempt to capture the perceptions these people have of their care in a medium secure unit. Methods: A phenomenological approach was used, and during in-depth interviews, the…

Defending Identity and Ethos: An Analysis of Teacher Perceptions of School Collaboration in Northern Ireland

ERIC Educational Resources Information Center

Donnelly, Caitlin

2012-01-01

The purpose of this article is to examine the process of collaborative working between teachers located in separate faith-based schools in Northern Ireland. Drawing on theories of intergroup relations, and with reference to in-depth interviews with teachers in post-primary schools, the article shows that despite earlier research which identified a…

Enabling Voice: Aboriginal Parents, Experiences and Perceptions of Sending a Child to Boarding School in Western Australia

ERIC Educational Resources Information Center

Mander, David J.

2015-01-01

This study explored the experience of having a child educated away from home at boarding school for Aboriginal parents living in regional and remote communities in Western Australia (WA). In-depth interviews were conducted with 11 participants and thematic analysis found the following major themes emerged from the data: (1) Access, Standards and…

Single-channel stereoscopic ophthalmology microscope based on TRD

NASA Astrophysics Data System (ADS)

Radfar, Edalat; Park, Jihoon; Lee, Sangyeob; Ha, Myungjin; Yu, Sungkon; Jang, Seulki; Jung, Byungjo

2016-03-01

A stereoscopic imaging modality was developed for the application of ophthalmology surgical microscopes. A previous study has already introduced a single-channel stereoscopic video imaging modality based on a transparent rotating deflector (SSVIM-TRD), in which two different view angles, image disparity, are generated by imaging through a transparent rotating deflector (TRD) mounted on a stepping motor and is placed in a lens system. In this case, the image disparity is a function of the refractive index and the rotation angle of TRD. Real-time single-channel stereoscopic ophthalmology microscope (SSOM) based on the TRD is improved by real-time controlling and programming, imaging speed, and illumination method. Image quality assessments were performed to investigate images quality and stability during the TRD operation. Results presented little significant difference in image quality in terms of stability of structural similarity (SSIM). A subjective analysis was performed with 15 blinded observers to evaluate the depth perception improvement and presented significant improvement in the depth perception capability. Along with all evaluation results, preliminary results of rabbit eye imaging presented that the SSOM could be utilized as an ophthalmic operating microscopes to overcome some of the limitations of conventional ones.

The screening of visual impairment among preschool children in an urban population in Malaysia; the Kuching pediatric eye study: a cross sectional study

PubMed Central

2013-01-01

Background To screen for visual impairment in Malaysian preschool children. Methods Visual screening was conducted in 400 preschool children aged 4 to 6 years. The screening involved two basic procedures; the distant visual acuity test using the Sheridan Gardiner chart and the depth perception test using the Langs stereoacuity test. Criteria for referral were a visual acuity of 6/12 or less in the better eye or a fail in the depth perception test. Results The prevalence of visual impairment was 5% (95% confidence interval [CI] = 3.3, 7.6). Of the 400 preschool children screened, 20 of them failed the distant visual acuity test or the stereopsis test. Refractive errors were the most common cause of visual impairment (95%, 95% CI = 76.2, 98.8); myopic astigmatism was the commonest type of refractive error (63.2%, 95% CI = 40.8, 80.9). Conclusion The study is a small but important step in the effort to understand the problem of visual impairment among our preschool children. Our study showed that it is feasible to measure distant visual acuity and stereopsis in this age group. PMID:23601160

Learning from “Knocks in Life”: Food Insecurity among Low-Income Lone Senior Women

PubMed Central

Green-LaPierre, Rebecca J.; Williams, Patricia L.; Glanville, N. Theresa; Norris, Deborah; Hunter, Heather C.; Watt, Cynthia G.

2012-01-01

Building on earlier quantitative work where we showed that lone senior households reliant on public pensions in Nova Scotia (NS), Canada lacked the necessary funds for a basic nutritious diet, here we present findings from a qualitative study involving in-depth interviews with eight low-income lone senior women living in an urban area of NS. Using a phenomenological inquiry approach, in-depth interviews were used to explore lone senior women's experiences accessing food with limited financial resources. Drawing upon Bronfenbrenner's Ecological Systems Theory, we explored their perceived ability to access a nutritionally adequate and personally acceptable diet, and the barriers and enablers to do so; as well in light of our previous quantitative research, we explored their perceptions related to adequacy of income, essential expenses, and their strategies to manage personal finances. Seven key themes emerged: world view, income adequacy, transportation, health/health problems, community program use, availability of family and friends, and personal food management strategies. World view exerted the largest influence on seniors' personal perception of food security status. The implications of the findings and policy recommendations to reduce the nutritional health inequities among this vulnerable subset of the senior population are considered. PMID:22997580

Visual abilities distinguish pitchers from hitters in professional baseball.

PubMed

Klemish, David; Ramger, Benjamin; Vittetoe, Kelly; Reiter, Jerome P; Tokdar, Surya T; Appelbaum, Lawrence Gregory

2018-01-01

This study aimed to evaluate the possibility that differences in sensorimotor abilities exist between hitters and pitchers in a large cohort of baseball players of varying levels of experience. Secondary data analysis was performed on 9 sensorimotor tasks comprising the Nike Sensory Station assessment battery. Bayesian hierarchical regression modelling was applied to test for differences between pitchers and hitters in data from 566 baseball players (112 high school, 85 college, 369 professional) collected at 20 testing centres. Explanatory variables including height, handedness, eye dominance, concussion history, and player position were modelled along with age curves using basis regression splines. Regression analyses revealed better performance for hitters relative to pitchers at the professional level in the visual clarity and depth perception tasks, but these differences did not exist at the high school or college levels. No significant differences were observed in the other 7 measures of sensorimotor capabilities included in the test battery, and no systematic biases were found between the testing centres. These findings, indicating that professional-level hitters have better visual acuity and depth perception than professional-level pitchers, affirm the notion that highly experienced athletes have differing perceptual skills. Findings are discussed in relation to deliberate practice theory.

The screening of visual impairment among preschool children in an urban population in Malaysia; the Kuching pediatric eye study: a cross sectional study.

PubMed

Premsenthil, Mallika; Manju, Rose; Thanaraj, Asokumaran; Rahman, Syed Alwi Syed Abdul; Kah, Tan Aik

2013-04-19

To screen for visual impairment in Malaysian preschool children. Visual screening was conducted in 400 preschool children aged 4 to 6 years. The screening involved two basic procedures; the distant visual acuity test using the Sheridan Gardiner chart and the depth perception test using the Langs stereoacuity test. Criteria for referral were a visual acuity of 6/12 or less in the better eye or a fail in the depth perception test. The prevalence of visual impairment was 5% (95% confidence interval [CI] = 3.3, 7.6). Of the 400 preschool children screened, 20 of them failed the distant visual acuity test or the stereopsis test. Refractive errors were the most common cause of visual impairment (95%, 95% CI = 76.2, 98.8); myopic astigmatism was the commonest type of refractive error (63.2%, 95% CI = 40.8, 80.9). The study is a small but important step in the effort to understand the problem of visual impairment among our preschool children. Our study showed that it is feasible to measure distant visual acuity and stereopsis in this age group.

Learning from "Knocks in Life": Food Insecurity among Low-Income Lone Senior Women.

PubMed

Green-Lapierre, Rebecca J; Williams, Patricia L; Glanville, N Theresa; Norris, Deborah; Hunter, Heather C; Watt, Cynthia G

2012-01-01

Building on earlier quantitative work where we showed that lone senior households reliant on public pensions in Nova Scotia (NS), Canada lacked the necessary funds for a basic nutritious diet, here we present findings from a qualitative study involving in-depth interviews with eight low-income lone senior women living in an urban area of NS. Using a phenomenological inquiry approach, in-depth interviews were used to explore lone senior women's experiences accessing food with limited financial resources. Drawing upon Bronfenbrenner's Ecological Systems Theory, we explored their perceived ability to access a nutritionally adequate and personally acceptable diet, and the barriers and enablers to do so; as well in light of our previous quantitative research, we explored their perceptions related to adequacy of income, essential expenses, and their strategies to manage personal finances. Seven key themes emerged: world view, income adequacy, transportation, health/health problems, community program use, availability of family and friends, and personal food management strategies. World view exerted the largest influence on seniors' personal perception of food security status. The implications of the findings and policy recommendations to reduce the nutritional health inequities among this vulnerable subset of the senior population are considered.

Exploring family environment characteristics and multiple abuse experiences among homeless youth.

PubMed

Ferguson, Kristin M

2009-11-01

This qualitative study used data from the Social Enterprise Intervention (SEI) pilot study, a comprehensive vocational training program with integrated clinical services for homeless youth. In-depth interviews were conducted with 28 homeless youth participating in the SEI study to explore their perceptions of family environment characteristics and abuse experiences. The constant comparative method was used to analyze transcripts from in-depth interviews with the youth participants. Emergent themes related to family characteristics include home instability, abandonment, and caregiver substance abuse. Abuse-related subthemes include intrafamilial abuse, caregiver abuse, rejection, and deprecation by caregivers. Grounded theory is used to interpret findings and develop working hypotheses to guide future studies of multitype maltreatment among homeless youth.

Edge-region grouping in figure-ground organization and depth perception.

PubMed

Palmer, Stephen E; Brooks, Joseph L

2008-12-01

Edge-region grouping (ERG) is proposed as a unifying and previously unrecognized class of relational information that influences figure-ground organization and perceived depth across an edge. ERG occurs when the edge between two regions is differentially grouped with one region based on classic principles of similarity grouping. The ERG hypothesis predicts that the grouped side will tend to be perceived as the closer, figural region. Six experiments are reported that test the predictions of the ERG hypothesis for 6 similarity-based factors: common fate, blur similarity, color similarity, orientation similarity, proximity, and flicker synchrony. All 6 factors produce the predicted effects, although to different degrees. In a 7th experiment, the strengths of these figural/depth effects were found to correlate highly with the strength of explicit grouping ratings of the same visual displays. The relations of ERG to prior results in the literature are discussed, and possible reasons for ERG-based figural/depth effects are considered. We argue that grouping processes mediate at least some of the effects we report here, although ecological explanations are also likely to be relevant in the majority of cases.

Edge-Region Grouping in Figure-Ground Organization and Depth Perception

PubMed Central

Palmer, Stephen E.; Brooks, Joseph L.

2008-01-01

Edge-region grouping (ERG) is proposed as a unifying and previously unrecognized class of relational information that influences figure-ground organization and perceived depth across an edge. ERG occurs when the edge between two regions is differentially grouped with one region based on classic principles of similarity grouping. The ERG hypothesis predicts that the grouped side will tend to be perceived as the closer, figural region. Six experiments are reported that test the predictions of the ERG hypothesis for six similarity-based factors: common fate, blur similarity, color similarity, orientation similarity, proximity, and flicker synchrony. All six factors produce the predicted effects, although to different degrees. In the seventh experiment, the strengths of these figural/depth effects were found to correlate highly with the strength of explicit grouping ratings of the same visual displays. The relations of ERG to prior results in the literature are discussed, and possible reasons for ERG-based figural/depth effects are considered. We argue that grouping processes mediate at least some of the effects we report here, although ecological explanations are also likely to be relevant in the majority of cases. PMID:19045980

'Because the baby asks for it': a mixed-methods study on local perceptions toward nutrition during pregnancy among marginalised migrant women along the Myanmar-Thailand border.

PubMed

Hashmi, Ahmar H; Paw, Moo Kho; Nosten, Suphak; Darakamon, Mu Chae; Gilder, Mary Ellen; Charunwatthana, Prakaykaew; Carrara, Verena I; Wickramasinghe, Kremlin; Angkurawaranon, Chaisiri; Plugge, Emma; McGready, Rose

2018-01-01

Under- and over-nutrition during pregnancy are known risk factors for pregnancy complications and adverse pregnancy and infant outcomes. Understanding perceptions around nutrition in pregnancy can create culturally appropriate interventions for improved health outcomes. A mixed-methods study was performed to explore local perceptions and practices of diet and physical activity in pregnancy in a marginalised population along the Myanmar-Thailand border. From April to July 2017, a cross-sectional survey and focus group discussions were conducted with pregnant women reporting to antenatal care; in-depth interviews were conducted with senior midwives at participating organisations along the Myanmar-Thailand border. A total of 388 pregnant women were interviewed at two clinic sites along the Myanmar-Thailand border. A high proportion of women had limited knowledge of and poor dietary practices. Consuming a sweetened drink in the last 24 hours as well as being a non-teenage, multigravida woman was significantly associated with high body mass index (BMI) compared to normal BMI. Qualitative analysis combined focus group discussions (n = 66) and in-depth interviews (n = 4) summarising emergent themes: common foods eaten or avoided and rationale; benefits of nutrition; perceptions of overweight and weight gain during pregnancy; barriers to a healthy diet; and sources of diet information. There is limited awareness about healthy diets and lifestyle in these marginalised, migrant communities along the Myanmar-Thailand border. This study suggests that simple, culturally appropriate messaging should be provided to women and communities with low health literacy to generate awareness about healthy lifestyles and their effects on pregnancy outcomes as an important element of a broader strategy to address maternal nutrition in this population. However, more studies to determine the effectiveness of a broad range of interventions in low- and middle-income countries (LMIC) are needed, especially in marginalised migrant populations.

Perception of object motion in three-dimensional space induced by cast shadows.

PubMed

Katsuyama, Narumi; Usui, Nobuo; Nose, Izuru; Taira, Masato

2011-01-01

Cast shadows can be salient depth cues in three-dimensional (3D) vision. Using a motion illusion in which a ball is perceived to roll in depth on the bottom or to flow in the front plane depending on the slope of the trajectory of its cast shadow, we investigated cortical mechanisms underlying 3D vision based on cast shadows using fMRI techniques. When modified versions of the original illusion, in which the slope of the shadow trajectory (shadow slope) was changed in 5 steps from the same one as the ball trajectory to the horizontal, were presented to participants, their perceived ball trajectory shifted gradually from rolling on the bottom to floating in the front plane as the change of the shadow slope. This observation suggests that the perception of the ball trajectory in this illusion is strongly affected by the motion of the cast shadow. In the fMRI study, cortical activity during observation of the movies of the illusion was investigated. We found that the bilateral posterior-occipital sulcus (POS) and right ventral precuneus showed activation related to the perception of the ball trajectory induced by the cast shadows in the illusion. Of these areas, it was suggested that the right POS may be involved in the inferring of the ball trajectory by the given spatial relation between the ball and the shadow. Our present results suggest that the posterior portion of the medial parietal cortex may be involved in 3D vision by cast shadows. Copyright © 2010 Elsevier Inc. All rights reserved.

Effects of various electrode configurations on music perception, intonation and speaker gender identification.

PubMed

Landwehr, Markus; Fürstenberg, Dirk; Walger, Martin; von Wedel, Hasso; Meister, Hartmut

2014-01-01

Advances in speech coding strategies and electrode array designs for cochlear implants (CIs) predominantly aim at improving speech perception. Current efforts are also directed at transmitting appropriate cues of the fundamental frequency (F0) to the auditory nerve with respect to speech quality, prosody, and music perception. The aim of this study was to examine the effects of various electrode configurations and coding strategies on speech intonation identification, speaker gender identification, and music quality rating. In six MED-EL CI users electrodes were selectively deactivated in order to simulate different insertion depths and inter-electrode distances when using the high definition continuous interleaved sampling (HDCIS) and fine structure processing (FSP) speech coding strategies. Identification of intonation and speaker gender was determined and music quality rating was assessed. For intonation identification HDCIS was robust against the different electrode configurations, whereas fine structure processing showed significantly worse results when a short electrode depth was simulated. In contrast, speaker gender recognition was not affected by electrode configuration or speech coding strategy. Music quality rating was sensitive to electrode configuration. In conclusion, the three experiments revealed different outcomes, even though they all addressed the reception of F0 cues. Rapid changes in F0, as seen with intonation, were the most sensitive to electrode configurations and coding strategies. In contrast, electrode configurations and coding strategies did not show large effects when F0 information was available over a longer time period, as seen with speaker gender. Music quality relies on additional spectral cues other than F0, and was poorest when a shallow insertion was simulated.

Binocular coordination in response to stereoscopic stimuli

NASA Astrophysics Data System (ADS)

Liversedge, Simon P.; Holliman, Nicolas S.; Blythe, Hazel I.

2009-02-01

Humans actively explore their visual environment by moving their eyes. Precise coordination of the eyes during visual scanning underlies the experience of a unified perceptual representation and is important for the perception of depth. We report data from three psychological experiments investigating human binocular coordination during visual processing of stereoscopic stimuli.In the first experiment participants were required to read sentences that contained a stereoscopically presented target word. Half of the word was presented exclusively to one eye and half exclusively to the other eye. Eye movements were recorded and showed that saccadic targeting was uninfluenced by the stereoscopic presentation, strongly suggesting that complementary retinal stimuli are perceived as a single, unified input prior to saccade initiation. In a second eye movement experiment we presented words stereoscopically to measure Panum's Fusional Area for linguistic stimuli. In the final experiment we compared binocular coordination during saccades between simple dot stimuli under 2D, stereoscopic 3D and real 3D viewing conditions. Results showed that depth appropriate vergence movements were made during saccades and fixations to real 3D stimuli, but only during fixations on stereoscopic 3D stimuli. 2D stimuli did not induce depth vergence movements. Together, these experiments indicate that stereoscopic visual stimuli are fused when they fall within Panum's Fusional Area, and that saccade metrics are computed on the basis of a unified percept. Also, there is sensitivity to non-foveal retinal disparity in real 3D stimuli, but not in stereoscopic 3D stimuli, and the system responsible for binocular coordination responds to this during saccades as well as fixations.

Stereoscopic camera and viewing systems with undistorted depth presentation and reduced or eliminated erroneous acceleration and deceleration perceptions, or with perceptions produced or enhanced for special effects

NASA Technical Reports Server (NTRS)

Diner, Daniel B. (Inventor)

1991-01-01

Methods for providing stereoscopic image presentation and stereoscopic configurations using stereoscopic viewing systems having converged or parallel cameras may be set up to reduce or eliminate erroneously perceived accelerations and decelerations by proper selection of parameters, such as an image magnification factor, q, and intercamera distance, 2w. For converged cameras, q is selected to be equal to Ve - qwl = 0, where V is the camera distance, e is half the interocular distance of an observer, w is half the intercamera distance, and l is the actual distance from the first nodal point of each camera to the convergence point, and for parallel cameras, q is selected to be equal to e/w. While converged cameras cannot be set up to provide fully undistorted three-dimensional views, they can be set up to provide a linear relationship between real and apparent depth and thus minimize erroneously perceived accelerations and decelerations for three sagittal planes, x = -w, x = 0, and x = +w which are indicated to the observer. Parallel cameras can be set up to provide fully undistorted three-dimensional views by controlling the location of the observer and by magnification and shifting of left and right images. In addition, the teachings of this disclosure can be used to provide methods of stereoscopic image presentation and stereoscopic camera configurations to produce a nonlinear relation between perceived and real depth, and erroneously produce or enhance perceived accelerations and decelerations in order to provide special effects for entertainment, training, or educational purposes.

Binocular disparity tuning and visual-vestibular congruency of multisensory neurons in macaque parietal cortex

PubMed Central

Yang, Yun; Liu, Sheng; Chowdhury, Syed A.; DeAngelis, Gregory C.; Angelaki, Dora E.

2012-01-01

Many neurons in the dorsal medial superior temporal (MSTd) and ventral intraparietal (VIP) areas of the macaque brain are multisensory, responding to both optic flow and vestibular cues to self-motion. The heading tuning of visual and vestibular responses can be either congruent or opposite, but only congruent cells have been implicated in cue integration for heading perception. Because of the geometric properties of motion parallax, however, both congruent and opposite cells could be involved in coding self-motion when observers fixate a world-fixed target during translation, if congruent cells prefer near disparities and opposite cells prefer far disparities. We characterized the binocular disparity selectivity and heading tuning of MSTd and VIP cells using random-dot stimuli. Most (70%) MSTd neurons were disparity-selective with monotonic tuning, and there was no consistent relationship between depth preference and congruency of visual and vestibular heading tuning. One-third of disparity-selective MSTd cells reversed their depth preference for opposite directions of motion (direction-dependent disparity tuning, DDD), but most of these cells were unisensory with no tuning for vestibular stimuli. Inconsistent with previous reports, the direction preferences of most DDD neurons do not reverse with disparity. By comparison to MSTd, VIP contains fewer disparity-selective neurons (41%) and very few DDD cells. On average, VIP neurons also preferred higher speeds and nearer disparities than MSTd cells. Our findings are inconsistent with the hypothesis that visual/vestibular congruency is linked to depth preference, and also suggest that DDD cells are not involved in multisensory integration for heading perception. PMID:22159105

How visual illusions illuminate complementary brain processes: illusory depth from brightness and apparent motion of illusory contours

PubMed Central

Grossberg, Stephen

2014-01-01

Neural models of perception clarify how visual illusions arise from adaptive neural processes. Illusions also provide important insights into how adaptive neural processes work. This article focuses on two illusions that illustrate a fundamental property of global brain organization; namely, that advanced brains are organized into parallel cortical processing streams with computationally complementary properties. That is, in order to process certain combinations of properties, each cortical stream cannot process complementary properties. Interactions between these streams, across multiple processing stages, overcome their complementary deficiencies to compute effective representations of the world, and to thereby achieve the property of complementary consistency. The two illusions concern how illusory depth can vary with brightness, and how apparent motion of illusory contours can occur. Illusory depth from brightness arises from the complementary properties of boundary and surface processes, notably boundary completion and surface-filling in, within the parvocellular form processing cortical stream. This illusion depends upon how surface contour signals from the V2 thin stripes to the V2 interstripes ensure complementary consistency of a unified boundary/surface percept. Apparent motion of illusory contours arises from the complementary properties of form and motion processes across the parvocellular and magnocellular cortical processing streams. This illusion depends upon how illusory contours help to complete boundary representations for object recognition, how apparent motion signals can help to form continuous trajectories for target tracking and prediction, and how formotion interactions from V2-to-MT enable completed object representations to be continuously tracked even when they move behind intermittently occluding objects through time. PMID:25389399

Cognitive responses and cortical oscillatory processing at various stereoscopic depths - a simultaneous EEG/MEG study.

PubMed

Cho, Hohyun; Kang, Min-Koo; Ahn, Sangtae; Kwon, Moonyoung; Yoon, Kuk-Jin; Kim, Kiwoong; Jun, Sung Chan

2017-01-01

Due to the recent explosion in various forms of 3D content, the evaluation of such content from a neuroscience perspective is quite interesting. However, existing investigations of cortical oscillatory responses in stereoscopic depth perception are quite rare. Therefore, we investigated spatiotemporal and spatio-temporo-spectral features at four different stereoscopic depths within the comfort zone. We adopted a simultaneous EEG/MEG acquisition technique to collect the oscillatory responses of eight participants. We defined subject-specific retinal disparities and designed a single trial-based stereoscopic viewing experimental paradigm. In the group analysis, we observed that, as the depth increased from Level 1 to Level 3, there was a time-locked increase in the N200 component in MEG and the P300 component in EEG in the occipital and parietal areas, respectively. In addition, initial alpha and beta event-related desynchronizations (ERD) were observed at approximately 500 to 1000 msec, while theta, alpha, and beta event-related synchronizations (ERS) appeared at approximately 1000 to 2000 ms. Interestingly, there was a saturation point in the increase in cognitive responses, including N200, P300, and alpha ERD, even when the depth increased only within the comfort zone. Meanwhile, the magnitude of low beta ERD decreased in the dorsal pathway as depth increased. From these findings, we concluded that cognitive responses are likely to become saturated in the visual comfort zone, while perceptual load may increase with depth.

Differential patterns of 2D location versus depth decoding along the visual hierarchy.

PubMed

Finlayson, Nonie J; Zhang, Xiaoli; Golomb, Julie D

2017-02-15

Visual information is initially represented as 2D images on the retina, but our brains are able to transform this input to perceive our rich 3D environment. While many studies have explored 2D spatial representations or depth perception in isolation, it remains unknown if or how these processes interact in human visual cortex. Here we used functional MRI and multi-voxel pattern analysis to investigate the relationship between 2D location and position-in-depth information. We stimulated different 3D locations in a blocked design: each location was defined by horizontal, vertical, and depth position. Participants remained fixated at the center of the screen while passively viewing the peripheral stimuli with red/green anaglyph glasses. Our results revealed a widespread, systematic transition throughout visual cortex. As expected, 2D location information (horizontal and vertical) could be strongly decoded in early visual areas, with reduced decoding higher along the visual hierarchy, consistent with known changes in receptive field sizes. Critically, we found that the decoding of position-in-depth information tracked inversely with the 2D location pattern, with the magnitude of depth decoding gradually increasing from intermediate to higher visual and category regions. Representations of 2D location information became increasingly location-tolerant in later areas, where depth information was also tolerant to changes in 2D location. We propose that spatial representations gradually transition from 2D-dominant to balanced 3D (2D and depth) along the visual hierarchy. Copyright © 2016 Elsevier Inc. All rights reserved.

The visual perception of exocentric distance in outdoor settings.

PubMed

Norman, J Farley; Adkins, Olivia C; Pedersen, Lauren E; Reyes, Cecia M; Wulff, Rachel A; Tungate, Alex

2015-12-01

The ability of 20 younger (mean age was 21.8years) and older adults (mean age was 71.5years) to visually perceive exocentric distances outdoors was evaluated. The observers adjusted the extent of in-depth spatial intervals until they appeared identical to fronto-parallel intervals of 4 and 8m. The frontal and in-depth intervals were viewed from a distance of 8m. Almost all of the observers' judgments were inaccurate and most reflected perceptual compressions in depth: e.g., an in-depth interval of 10m would appear to have the same extent as a physically smaller 8m frontal interval. Some observers' judgments, however, were consistent with perceptual expansions of in-depth intervals. No significant effects of age were obtained in the current study: both younger and older adults exhibited perceptual compressions and expansions of in-depth intervals. This outcome differs from that of a recent experiment conducted by our laboratory (Vision Research 109 (2015) 52-58) that found the judgments of younger adults to be less accurate than those of older adults. A comparison of the former and current results revealed that while older adults perform similarly outdoors and indoors, the accuracy of younger adults' exocentric judgements improves substantially in outdoor settings (so that the accuracy becomes similar to that exhibited by older adults). Copyright © 2015 Elsevier Ltd. All rights reserved.

Students' Perceptions of the Long-Term Impact of Attending a "CSI Science Camp"

ERIC Educational Resources Information Center

Yanowitz, Karen L.

2016-01-01

A science summer camp is a popular type of informal science experience for youth. While there is no one model of a science camp, these experiences typically allow for more focused and in-depth exploration of different science domains and are usually hands-on and participatory. The goal of this research was to examine the impact of a short science…

Perceptions of the Host Country's Food Culture among Female Immigrants from Africa and Asia: Aspects Relevant for Cultural Sensitivity in Nutrition Communication

ERIC Educational Resources Information Center

Garnweidner, Lisa Maria; Terragni, Laura; Pettersen, Kjell Sverre; Mosdol, Annhild

2012-01-01

Objective: To explore how female immigrants from Africa and Asia perceive the host country's food culture, to identify aspects of their original food culture they considered important to preserve, and to describe how they go about preserving them. Design: Qualitative in-depth interviews. Setting: Oslo, Norway. Participants: Twenty one female…

Unseen Workers in the Academic Factory: Perceptions of Neoracism among International Postdocs in the United States and the United Kingdom

ERIC Educational Resources Information Center

Cantwell, Brendan; Lee, Jenny J.

2010-01-01

In this article, Brendan Cantwell and Jenny J. Lee examine the experiences of international postdocs and their varying career paths in the current political economy of academic capitalism through the lens of neoracism. Using in-depth interviews with science and engineering faculty and international postdocs in the United States and the United…

Influence of Occupational Socialization on the Practices and Perspectives of Two Inexperienced Adventure Educators

ERIC Educational Resources Information Center

Zmudy, Mark H.; Curtner-Smith, Matthew D.; Steffen, Jeff

2009-01-01

A relatively small number of researchers have found it interesting and useful to examine why and how persons choose to be and become adventure educators (AEs) and why they teach as they do. The implications of this knowledge are: (1) gaining insight into novice AEs' perceptions of what is required to provide in-depth and high quality instruction…

Foster Youth and Post-Secondary Education: A Study of the Barriers and Supports That Led to Academic Achievement

ERIC Educational Resources Information Center

Morton, Brenda M.

2012-01-01

The purpose of this qualitative research study was to explore the perceptions of former and current foster youth on the barriers, supports, helps, and strategies they encountered during their K-12 education, and to learn how these contributed to their ability to enroll in post-secondary education. The study included in-depth interviews of 11…

The Competence and Warmth of Thai Students' Attitudes towards Varieties of English: The Effect of Gender and Perceptions of L1 Diversity

ERIC Educational Resources Information Center

McKenzie, Robert M.; Kitikanan, Patchanok; Boriboon, Phaisit

2016-01-01

Previous language attitude research indicates that presenting speech forms allows listeners to index information about and attach social meaning to the perceived group(s) of speakers. Despite the volume of research undertaken elsewhere in Asia, there appear to be no in-depth studies investigating Thai nationals' evaluations of specific varieties…

"YouTube Has Changed Everything"? Music Faculty, Librarians, and Their Use and Perceptions of Youtube

ERIC Educational Resources Information Center

Dougan, Kirstin

2014-01-01

YouTube's accessibility, ease of use, and depth of content are strong lures for music students. But do music teaching faculty and librarians encourage this and do they use it in their own research, teaching, and work? This study surveyed over 9,000 music faculty and over 300 music librarians in the United States. It discovered that faculty rank is…

"My Mom Tells Me I Should Follow the Rules, That's Why They Have Those Rules": Perceptions of Parental Advice Giving among Mexican-Heritage Adolescents

ERIC Educational Resources Information Center

Holloway, Susan D.; Park, Sira; Jonas, Michele; Bempechat, Janine; Li, Jin

2014-01-01

Relatively little research has examined the ways in which immigrant Latino parents can effectively support their adolescent children's schooling. To address this gap, we conducted in-depth interviews with 32 Mexican-heritage 9th graders. Students identified parents' advice giving as the most salient form of involvement. Parental advice emphasized…

Latino/a Students' Perceptions of Their Sense of Belonging at Kansas State University: Mi Casa Es Su Casa... or Is It Really?

ERIC Educational Resources Information Center

Esquivel, Sonia

2010-01-01

This qualitative multiple case study explored the campus climate and sense of belonging of Latino/a undergraduate student participants at a predominately White university. Guided by the work of Hurtado and Carter (1997), relationships among several aspects of the college environment and sense of belonging were examined. In depth interviews…

Academic Library Administration: A Case Examination of Faculty-Librarian Perceptions of Journal Cancellations and the Decision-Making Process in a Large, Urban Institution.

ERIC Educational Resources Information Center

Walther, James Harmon

As the academic library plays the roles of intermediary and adjudicator of collection purchases and cancellations, faculty involvement in library resource decisions is not only commonplace, but essential to making such decisions. Faculty involvement in cancellation projects is often enhanced by a thorough explanation of the depth of financial…

Assessed Perceptions of Female Materials Science and Engineering Graduates on Academic Advising, Student Support Services and Retention Strategies

ERIC Educational Resources Information Center

Washington, Renita Linette

2013-01-01

Females currently undertaking STEM-related programs can benefit from knowing about how other females who had been in a similar position as them were able to persevere through the challenges of higher education with the help of advisement and student support services that aim to increasing student retention. While there have been a depth of studies…

Teaching a Pedagogy of Peace: A Study of Peace Educators in United States Schools in the Aftermath of September 11

ERIC Educational Resources Information Center

Joseph, Pamela Bolotin; Duss, Leslie Smith

2009-01-01

This qualitative study, based on in-depth semi-structured interviews, depicts practices of seven peace educators in public elementary and secondary classrooms in the United States during the time of the terrorist attacks on 11 September 2001 through the US engagement in war in Afghanistan and Iraq. Focusing on individual perceptions of practice…

Strategies for the Interpretive Integration of Ground and Aerial Views in UGV Operations

DTIC Science & Technology

2006-11-01

conjoinment of the psychological processes and effects of perception, object recognition (i.e. Biederman & Gerhardstein, 1993), navigation (Wickens...rather simple geon structural descriptions (GSD, see Biederman & 4 Gerhardstein, 1993). A geon is a basic three dimensional solid shape, such as a...large and reliable sex difference. Behavioral Brain Research, 93, 185-190. Biederman , I., & Gerhardstein, C. (1993). Recognizing depth- rotated objects

Spatial constraints of stereopsis in video displays

NASA Technical Reports Server (NTRS)

Schor, Clifton

1989-01-01

Recent development in video technology, such as the liquid crystal displays and shutters, have made it feasible to incorporate stereoscopic depth into the 3-D representations on 2-D displays. However, depth has already been vividly portrayed in video displays without stereopsis using the classical artists' depth cues described by Helmholtz (1866) and the dynamic depth cues described in detail by Ittleson (1952). Successful static depth cues include overlap, size, linear perspective, texture gradients, and shading. Effective dynamic cues include looming (Regan and Beverly, 1979) and motion parallax (Rogers and Graham, 1982). Stereoscopic depth is superior to the monocular distance cues under certain circumstances. It is most useful at portraying depth intervals as small as 5 to 10 arc secs. For this reason it is extremely useful in user-video interactions such as telepresence. Objects can be manipulated in 3-D space, for example, while a person who controls the operations views a virtual image of the manipulated object on a remote 2-D video display. Stereopsis also provides structure and form information in camouflaged surfaces such as tree foliage. Motion parallax also reveals form; however, without other monocular cues such as overlap, motion parallax can yield an ambiguous perception. For example, a turning sphere, portrayed as solid by parallax can appear to rotate either leftward or rightward. However, only one direction of rotation is perceived when stereo-depth is included. If the scene is static, then stereopsis is the principal cue for revealing the camouflaged surface structure. Finally, dynamic stereopsis provides information about the direction of motion in depth (Regan and Beverly, 1979). Clearly there are many spatial constraints, including spatial frequency content, retinal eccentricity, exposure duration, target spacing, and disparity gradient, which - when properly adjusted - can greatly enhance stereodepth in video displays.

Healthcare-seeking behaviors of older Iranian immigrants: health perceptions and definitions.

PubMed

Martin, Shadi Sahami

2009-01-01

The purpose of this qualitative study was to explore how cultural differences influence the healthcare-seeking behaviors of older Iranian immigrants in the United States. Cultural differences were examined in a variety of areas, including definitions and perceptions of health, illness, and care. Using a phenomenological methodology, in-depth, semi-structured interviews were conducted with older Iranian immigrants. The findings of this study showed that participants' definitions of health, illness, and care differ significantly from mainstream Western definitions. An understanding of these cultural differences helps explain why older Iranian immigrants may or may not seek healthcare when they need it in the United States. Recommendations for change include cultural training for medical staff and the use of cultural brokers.

Caregiving for mental health service users: A study exploring the perceptions of mental health service users and their caregivers in Cape Town, South Africa.

PubMed

Sibeko, Goodman; Milligan, Peter D; Temmingh, Henk; Lund, Crick; Stein, Dan J; Mall, Sumaya

2016-09-01

Our study explores perceptions of the caregiver support for mental health service users (MHSUs) in a low- to middle-income country setting. We conducted in-depth individual interviews with 16 MHSUs and their treatment partners/caregivers from a treatment partner and text-message intervention study. Treatment partners/caregivers felt obligated to care for MHSUs, but had a limited understanding of mental illness. They found supporting adherence to treatment difficult due to a number of factors including violence, food insecurity and substance abuse. Socioeconomic and environmental factors affecting the lives of MHSUs have impact on caregiver relationships with MHSUs in their care. © The Author(s) 2016.

Perceptions of the Role of Mothers in the Disclosure and Nondisclosure of Child Sexual Abuse: A Qualitative Study.

PubMed

Hunter, Sally V

2015-01-01

One of the aims of this research was to develop an understanding of the role mothers were perceived to play during the process of disclosure of child sexual abuse. Using narrative inquiry methodology, face-to-face in-depth interviews were conducted with 22 men and women who had an early sexual experience. Even though a mother's support and protection is known to be important, this study showed that many mothers were seen as unable to offer such support, which had an important influence on nondisclosure. The heterogeneity of perceptions of mothers among adults who experienced child sexual abuse and gender differences are described. Health professionals need to manage complex relational dynamics between adult survivors and their mothers.

Women's perceptions and experiences of sexual violence in marital relationships and its effect on reproductive health.

PubMed

Hussain, Rafat; Khan, Adeel

2008-05-01

In this article we explore women's perceptions and experiences of sexual violence in marital relationships and its effects on reproductive health. We conducted a qualitative study composed of key informant interviews, focus group discussions, and in-depth interviews in two low- to middle-income areas of Karachi, Pakistan. Results show sexual coercion and nonconsensual sex were common and not limited to abusive relationships. Difficulties in negotiating safe sex resulted in unwanted pregnancies, some leading to unsafe abortions. The women reported escalation of violence during pregnancy to be common. Social norms prevented disclosure of sexual violence leading to limited support or intervention or both. The link between women's social status, marital violence, and reproductive health is discussed.

“You Must Know Where You Come From”: South African Youths' Perceptions of Religion in Time of Social Change

PubMed Central

Brittian, Aerika S.; Lewin, Nina; Norris, Shane A.

2014-01-01

This study examined South African youths' perceptions of religion during a period of social and economic transition. In-depth interviews were conducted with 55 Black South African youth (age 18) living in the Johannesburg-Soweto metropolitan area. Data were analyzed in a manner consistent with grounded theory methodology and structural coding. Beliefs about the function of religion were captured by the following themes: provides support, connection to the past, moral compass, promotes healthy development, and intersections between African traditional practices and Christian beliefs. Themes are discussed and directions for future research are presented. In addition, applications of the current research and implications for promoting youths' resilience are offered. PMID:24932064

Women's perceptions of the quality of emergency obstetric care in a referral hospital in rural Tanzania.

PubMed

Stal, Karen Berit; Pallangyo, Pedro; van Elteren, Marianne; van den Akker, Thomas; van Roosmalen, Jos; Nyamtema, Angelo

2015-07-01

To assess perceptions of the quality of obstetric care of women who delivered in a rural Tanzanian referral hospital. A descriptive-exploratory qualitative study, using semistructured in-depth interviews and participatory observation. Nineteen recently delivered women and 3 health workers were interviewed. Although most women held positive views about the care they received in hospital, several participants expressed major concerns about negative attitudes of healthcare workers. Lack of medical communication given by care providers constituted a major complaint. A more positive attitude by health workers and the provision of adequate medical information may promote a more positive hospital experience of women in need of obstetric care and enhance attendance. © 2015 John Wiley & Sons Ltd.

Warming the nursing education climate for traditional-age learners who are male.

PubMed

Bell-Scriber, Marietta J

2008-01-01

For nurse educators to facilitate student learning and the achievement of desired cognitive, affective, and psychomotor outcomes, they need to be competent in recognizing the influence of gender, experience, and other factors on teaching and learning. A study was conducted in one academic institution to describe how traditional-age male learners' perceptions of the nursing education climate compare to perceptions of female learners. Interviews were conducted with a sample of four male and four female learners. Additional data from interviews with nurse educators, classroom observations, and a review of textbooks provided breadth and depth to their perceptions. Findings support a nursing education climate that is cooler to traditional-age male learners and warmer to traditional-age female learners. The main cooling factor for men was caused by nurse educators' characteristics and unsupportive behaviors. Additional factors inside and outside the education environment contributed to a cooler climate for the male learners. Based on these findings, strategies for nurse educators to warm the education climate for traditional-age male learners are presented.

An exploration of how perceptions of the risk of avian influenza in poultry relate to urbanization in Vietnam.

PubMed

Finucane, Melissa L; Nghiem, Tuyen; Saksena, Sumeet; Nguyen, Lam; Fox, Jefferson; Spencer, James H; Thau, Trinh Dinh

2014-01-01

This research examined how perceptions of outbreaks of highly pathogenic avian influenza (HPAI) subtype H5N1 in poultry are related to urbanization. Via in-depth interviews with village leaders, household farmers, and large farm operators in modern, transitional, and traditional communes in the north of Vietnam, we explored behaviors, attitudes, cultural values, and traditions that might amplify or attenuate HPAI outbreaks. We also explored conceptualizations of urbanization and its impacts on animal husbandry and disease outbreaks. Qualitative theme analyses identified the key impacts, factors related to HPAI outbreaks, and disease prevention and management strategies. The analyses also highlighted how urbanization improves some aspects of life (e.g., food security, family wealth and health, more employment opportunities, and improved infrastructure), but simultaneously poses significant challenges for poultry farming and disease management. Awareness of qualitative aspects of HPAI risk perceptions and behaviors and how they vary with urbanization processes may help to improve the prevention and management of emerging infectious diseases.

Hypertensive patients' preferences for complementary and alternative medicine and the influence of these preferences on the adherence to prescribed medication.

PubMed

Lee, Khuan; Mokhtar, Halimatun Halaliah; Krauss, Steven Eric; Ong, Beng Kok

2014-05-01

This study aimed to understand hypertensive patients' perceptions of and adherence to prescribed medication. A qualitative research study based on 23 purposely selected participants from a community health clinic in Malaysia. The participants underwent in-depth semi-structured interviews, and the data were analyzed using qualitative content analysis method. The participants were presented with six types of perceptions of medication. The majority of the participants had negative perceptions of Western medicine (WM), self-adjusted their prescribed medication with complementary and alternative medicine (CAM) and concealed their self-adjusting habits from their doctors. Participants who thought positively of WM took their prescribed medication regularly. Most of the participants perceived the nature of WM as not being curative because of its side effects. Patients have the right to choose their preferred medication when they understand their illness. Local health care systems should provide patients with alternative health services that suit their requests. Copyright © 2014 Elsevier Ltd. All rights reserved.

Students' perceptions of the non-academic advantages and disadvantages of participation in Advanced Placement courses and International Baccalaureate programs.

PubMed

Foust, Regan Clark; Hertberg-Davis, Holly; Callahan, Carolyn M

2009-01-01

In-depth interviews of students with qualitative analysis of the responses were used to explore perceptions of the non-academic advantages and disadvantages of Advanced Placement (AP) and International Baccalaureate (IB) program participation, and differences between the AP and IB programs in those perceptions. Results revealed that benefits of participation, including pride in completing more challenging work, similarity and special bonds among participants, better treatment (more respect and responsibility) from teachers, better overall class atmosphere, and preference for AP and IB courses were consistent across schools and between programs. Also consistent were the disadvantages students reported, with marked differences in the intensity of disadvantages between the AP and IB programs. Specifically, as the amount of time students spent in homogeneously grouped settings increased, so did the workload, the intensity of the perceived social/emotional disadvantages of the workload, the perceived range of negative feelings between participants and non-participants, and the perceived negativity of participant strereotypes.

Gender inequities in health: an exploratory qualitative study of Saudi women's perceptions.

PubMed

Alyaemni, Asmaa; Theobald, Sally; Faragher, Brian; Jehan, Kate; Tolhurst, Rachel

2013-01-01

This study aimed to explore Saudi Arabian women's perceptions of how gendered social structures affect their health by understanding their perceptions of these influences on their health relative to those on men's health. Qualitative methods, including focus group discussions (FGDs) and in-depth individual interviews (IDIs) were conducted with 66 married women in Riyadh, the capital city. Participants were purposively sampled for maximum variation, including consideration of socio-economic status, age, educational level, health status and the use of healthcare. The majority of women perceived their health to be worse than men's and attributed this to their childbearing, domestic and care-giving roles, restrictions on their mobility, poverty and psychological stress related to their responsibilities for children, and marital conflict. A minority of participants felt that men's health was worse than women's and related this to their gendered roles as "breadwinners," greater mobility and masculine norms and identities. Gender equity should be a health policy priority to improve women's health.

“It’s One of the Better Drugs to Use”: Perceptions of Cocaine Use Among Gay and Bisexual Asian American Men

PubMed Central

Fazio, Adam; Hunt, Geoffrey; Moloney, Molly

2010-01-01

Research on drug use among gay and bisexual men has primarily focused on examining the link between drug use – most notably, methamphetamine – sexual practices, and risk of HIV transmission. Drawing on in-depth qualitative data from 40 interviews with gay and bisexual Asian American men, we examine perceptions and meanings associated with cocaine use in the San Francisco Bay Area gay community. We found that our participants, in contrast to their negative perceptions of methamphetamine use, believed that cocaine enhanced sociability and was acceptable for use in most social situations. Furthermore, participants perceived little connection between cocaine use and risky sexual practices, emphasizing the drug’s safety relative to other illicit substances. Overall, these findings suggest that an increase in the favorability of cocaine use might be an unintended consequence of methamphetamine prevention campaigns, targeting the gay community, with their emphasis on the harmful effects of drug use, unsafe sex and HIV risk. PMID:20952603

Keep Your Eyes on Development: The Behavioral and Neurophysiological Development of Visual Mechanisms Underlying Form Processing

PubMed Central

van den Boomen, C.; van der Smagt, M. J.; Kemner, C.

2012-01-01

Visual form perception is essential for correct interpretation of, and interaction with, our environment. Form perception depends on visual acuity and processing of specific form characteristics, such as luminance contrast, spatial frequency, color, orientation, depth, and even motion information. As other cognitive processes, form perception matures with age. This paper aims at providing a concise overview of our current understanding of the typical development, from birth to adulthood, of form-characteristic processing, as measured both behaviorally and neurophysiologically. Two main conclusions can be drawn. First, the current literature conveys that for most reviewed characteristics a developmental pattern is apparent. These trajectories are discussed in relation to the organization of the visual system. The second conclusion is that significant gaps in the literature exist for several age-ranges. To complete our understanding of the typical and, by consequence, atypical development of visual mechanisms underlying form processing, future research should uncover these missing segments. PMID:22416236

Bayesian modeling of cue interaction: bistability in stereoscopic slant perception.

PubMed

van Ee, Raymond; Adams, Wendy J; Mamassian, Pascal

2003-07-01

Our two eyes receive different views of a visual scene, and the resulting binocular disparities enable us to reconstruct its three-dimensional layout. However, the visual environment is also rich in monocular depth cues. We examined the resulting percept when observers view a scene in which there are large conflicts between the surface slant signaled by binocular disparities and the slant signaled by monocular perspective. For a range of disparity-perspective cue conflicts, many observers experience bistability: They are able to perceive two distinct slants and to flip between the two percepts in a controlled way. We present a Bayesian model that describes the quantitative aspects of perceived slant on the basis of the likelihoods of both perspective and disparity slant information combined with prior assumptions about the shape and orientation of objects in the scene. Our Bayesian approach can be regarded as an overarching framework that allows researchers to study all cue integration aspects-including perceptual decisions--in a unified manner.

Mental Representation of Spatial Cues During Spaceflight (3D-SPACE)

NASA Astrophysics Data System (ADS)

Clement, Gilles; Lathan, Corinna; Skinner, Anna; Lorigny, Eric

2008-06-01

The 3D-SPACE experiment is a joint effort between ESA and NASA to develop a simple virtual reality platform to enable astronauts to complete a series of tests while aboard the International Space Station (ISS). These tests will provide insights into the effects of the space environment on: (a) depth perception, by presenting 2D geometric illusions and 3D objects that subjects adjust with a finger trackball; (b) distance perception, by presenting natural or computer-generated 3D scenes where subjects estimate and report absolute distances or adjust distances; and (c) handwriting/drawing, by analyzing trajectories and velocities when subjects write or draw memorized objects with an electronic pen on a digitizing tablet. The objective of these tasks is to identify problems associated with 3D perception in astronauts with the goal of developing countermeasures to alleviate any associated performance risks. The equipment has been uploaded to the ISS in April 2008, and the first measurements should take place during Increment 17.

Survey Development to Assess College Students' Perceptions of the Campus Environment.

PubMed

Sowers, Morgan F; Colby, Sarah; Greene, Geoffrey W; Pickett, Mackenzie; Franzen-Castle, Lisa; Olfert, Melissa D; Shelnutt, Karla; Brown, Onikia; Horacek, Tanya M; Kidd, Tandalayo; Kattelmann, Kendra K; White, Adrienne A; Zhou, Wenjun; Riggsbee, Kristin; Yan, Wangcheng; Byrd-Bredbenner, Carol

2017-11-01

We developed and tested a College Environmental Perceptions Survey (CEPS) to assess college students' perceptions of the healthfulness of their campus. CEPS was developed in 3 stages: questionnaire development, validity testing, and reliability testing. Questionnaire development was based on an extensive literature review and input from an expert panel to establish content validity. Face validity was established with the target population using cognitive interviews with 100 college students. Concurrent-criterion validity was established with in-depth interviews (N = 30) of college students compared to surveys completed by the same 30 students. Surveys completed by college students from 8 universities (N = 1147) were used to test internal structure (factor analysis) and internal consistency (Cronbach's alpha). After development and testing, 15 items remained from the original 48 items. A 5-factor solution emerged: physical activity (4 items, α = .635), water (3 items, α = .773), vending (2 items, α = .680), healthy food (2 items, α = .631), and policy (2 items, α = .573). The mean total score for all universities was 62.71 (±11.16) on a 100-point scale. CEPS appears to be a valid and reliable tool for assessing college students' perceptions of their health-related campus environment.

Health workers' perceptions of private-not-for-profit health facilities' organizational culture and its influence on retention in Uganda.

PubMed

Shumba, Constance Sibongile; Kielmann, Karina; Witter, Sophie

2017-12-06

An in-depth understanding of how organizational culture is experienced by health workers (HWs), and influences their decisions to leave their jobs is a fundamental, yet under-examined, basis for forming effective retention strategies. This research examined HWs' working experiences and perceptions of organisational culture within private-not-for-profit, largely mission-based hospitals, and how this influenced retention. Thirty-two HWs, including managers, in 19 health facilities in Uganda were interviewed using a semi-structured topic guide. Interview transcripts were analysed using thematic content analysis. Interviews showed that the organizational culture was predominantly hierarchical, with non-participative management styles which emphasized control and efficiency. HWs and managers held different perceptions of the organizational culture. While the managers valued results and performance, HWs valued team work, recognition and participative management. The findings of this study indicate that organizational culture influences retention of HWs in health facilities and provide a useful context to inform health care managers in the PNFP sub-sector in Uganda and similar contexts. To improve retention of HWs, a gradual shift in organizational culture will be necessary, focussing on the values, beliefs and perceptions which have the greatest influence on observable behaviour.

Human perception considerations for 3D content creation

NASA Astrophysics Data System (ADS)

Green, G. Almont

2011-03-01

Observation and interviews with people viewing autostereoscopic 3D imagery provides evidence that there are many human perception considerations required for 3D content creation. A study was undertaken whereby it was witnessed that certain test autostereoscopic imagery elicited a highly emotional response and engagement, while other test autostereoscopic imagery was given only a passing glance. That an image can be viewed with a certain level of stereopsis does not make it compelling. By taking into consideration the manner in which humans perceive depth and the space between objects, 3D content can achieve a level of familiarity and realness that is not possible with single perspective imagery. When human perception issues are ignored, 3D imagery can be undesirable to viewers and a negative bias against 3D imagery can occur. The preparation of 3D content is more important than the display technology. Where human perception, as it is used to interpret reality, is not mimicked in the creation of 3D content, the general public typically express a negative bias against that imagery (where choices are provided). For some, the viewing of 3D content that could not exist naturally, induces physical discomfort.

Access, use and perceptions regarding Internet, cell phones and PDAs as a means for health promotion for people living with HIV in Peru

PubMed Central

Curioso, Walter H; Kurth, Ann E

2007-01-01

Background Internet tools, cell phones, and other information and communication technologies are being used by HIV-positive people on their own initiative. Little is known about the perceptions of HIV-positive people towards these technologies in Peru. The purpose of this paper is to report on perceptions towards use of information and communication technologies as a means to support antiretroviral medication adherence and HIV transmission risk reduction. Methods We conducted a qualitative study (in-depth interviews) among adult people living with HIV in two community-based clinics in Peru. Results 31 HIV-positive individuals in Lima were interviewed (n = 28 men, 3 women). People living with HIV in Peru are using tools such as cell phones, and the Internet (via E-mail, chat, list-serves) to support their HIV care and to make social and sexual connections. In general, they have positive perceptions about using the Internet, cell phones and PDAs for HIV health promotion interventions. Conclusion Health promotion interventions using information and communication technology tools among people living with HIV in resource-constrained settings may be acceptable and feasible, and can build on existing patterns of use. PMID:17850656

Access, use and perceptions regarding Internet, cell phones and PDAs as a means for health promotion for people living with HIV in Peru.

PubMed

Curioso, Walter H; Kurth, Ann E

2007-09-12

Internet tools, cell phones, and other information and communication technologies are being used by HIV-positive people on their own initiative. Little is known about the perceptions of HIV-positive people towards these technologies in Peru. The purpose of this paper is to report on perceptions towards use of information and communication technologies as a means to support antiretroviral medication adherence and HIV transmission risk reduction. We conducted a qualitative study (in-depth interviews) among adult people living with HIV in two community-based clinics in Peru. 31 HIV-positive individuals in Lima were interviewed (n = 28 men, 3 women). People living with HIV in Peru are using tools such as cell phones, and the Internet (via E-mail, chat, list-serves) to support their HIV care and to make social and sexual connections. In general, they have positive perceptions about using the Internet, cell phones and PDAs for HIV health promotion interventions. Health promotion interventions using information and communication technology tools among people living with HIV in resource-constrained settings may be acceptable and feasible, and can build on existing patterns of use.

Food and personal hygiene perceptions and practices among caregivers whose children have diarrhea: a qualitative study of urban mothers in Tangerang, Indonesia.

PubMed

Usfar, Avita A; Iswarawanti, Dwi N; Davelyna, Devy; Dillon, Drupadi

2010-01-01

To examine caregivers' perceptions and practices related to food and personal hygiene and its association with diarrhea in children 6 to 36 months of age who suffered recurrent diarrhea. This qualitative study, conducted in March and April 2006, used both in-depth interviews and direct observation data. Urban Tangerang, near Jakarta, Indonesia. Twenty-four mothers whose monthly household income was less than $160 US and had latrines in their homes. To examine the relationship between mothers' perceptions and behaviors related to diarrhea, food hygiene, and personal hygiene. Interview transcripts were analyzed based on the phenomenon of interest and coded for common themes. Mothers differentiated diarrhea episodes as either disease or nondisease. Most mothers associated the importance of food hygiene with disease prevention, contaminating agents, and health. Mothers commonly wiped cutting boards with a kitchen towel after slicing vegetables, whereas they washed the board with soap and water after cutting raw meat. Mothers perceived that the importance of personal hygiene was for maintaining health and cleanliness. The majority of mothers washed their hands without soap after performing housework and cooking. Improving mothers' knowledge while incorporating existing perceptions might lead to positive changes.

Contrasting accounts of direction and shape perception in short-range motion: Counterchange compared with motion energy detection.

PubMed

Norman, Joseph; Hock, Howard; Schöner, Gregor

2014-07-01

It has long been thought (e.g., Cavanagh & Mather, 1989) that first-order motion-energy extraction via space-time comparator-type models (e.g., the elaborated Reichardt detector) is sufficient to account for human performance in the short-range motion paradigm (Braddick, 1974), including the perception of reverse-phi motion when the luminance polarity of the visual elements is inverted during successive frames. Human observers' ability to discriminate motion direction and use coherent motion information to segregate a region of a random cinematogram and determine its shape was tested; they performed better in the same-, as compared with the inverted-, polarity condition. Computational analyses of short-range motion perception based on the elaborated Reichardt motion energy detector (van Santen & Sperling, 1985) predict, incorrectly, that symmetrical results will be obtained for the same- and inverted-polarity conditions. In contrast, the counterchange detector (Hock, Schöner, & Gilroy, 2009) predicts an asymmetry quite similar to that of human observers in both motion direction and shape discrimination. The further advantage of counterchange, as compared with motion energy, detection for the perception of spatial shape- and depth-from-motion is discussed.

Red fluorescence of the triplefin Tripterygion delaisi is increasingly visible against background light with increasing depth.

PubMed

Bitton, Pierre-Paul; Harant, Ulrike K; Fritsch, Roland; Champ, Connor M; Temple, Shelby E; Michiels, Nico K

2017-03-01

The light environment in water bodies changes with depth due to the absorption of short and long wavelengths. Below 10 m depth, red wavelengths are almost completely absent rendering any red-reflecting animal dark and achromatic. However, fluorescence may produce red coloration even when red light is not available for reflection. A large number of marine taxa including over 270 fish species are known to produce red fluorescence, yet it is unclear under which natural light environment fluorescence contributes perceptively to their colours. To address this question we: (i) characterized the visual system of Tripterygion delaisi, which possesses fluorescent irides, (ii) separated the colour of the irides into its reflectance and fluorescence components and (iii) combined these data with field measurements of the ambient light environment to calculate depth-dependent perceptual chromatic and achromatic contrasts using visual modelling. We found that triplefins have cones with at least three different spectral sensitivities, including differences between the two members of the double cones, giving them the potential for trichromatic colour vision. We also show that fluorescence contributes increasingly to the radiance of the irides with increasing depth. Our results support the potential functionality of red fluorescence, including communicative roles such as species and sex identity, and non-communicative roles such as camouflage.

Depth Perception and the History of Three-Dimensional Art: Who Produced the First Stereoscopic Images?

PubMed Central

2017-01-01

The history of the expression of three-dimensional structure in art can be traced from the use of occlusion in Palaeolithic cave paintings, through the use of shadow in classical art, to the development of perspective during the Renaissance. However, the history of the use of stereoscopic techniques is controversial. Although the first undisputed stereoscopic images were presented by Wheatstone in 1838, it has been claimed that two sketches by Jacopo Chimenti da Empoli (c. 1600) can be to be fused to yield an impression of stereoscopic depth, while others suggest that Leonardo da Vinci’s Mona Lisa is the world’s first stereogram. Here, we report the first quantitative study of perceived depth in these works, in addition to more recent works by Salvador Dalí. To control for the contribution of monocular depth cues, ratings of the magnitude and coherence of depth were recorded for both stereoscopic and pseudoscopic presentations, with a genuine contribution of stereoscopic cues revealed by a difference between these scores. Although effects were clear for Wheatstone and Dalí’s images, no such effects could be found for works produced earlier. As such, we have no evidence to reject the conventional view that the first producer of stereoscopic imagery was Sir Charles Wheatstone. PMID:28203349

Depth Perception and the History of Three-Dimensional Art: Who Produced the First Stereoscopic Images?

PubMed

Brooks, Kevin R

2017-01-01

The history of the expression of three-dimensional structure in art can be traced from the use of occlusion in Palaeolithic cave paintings, through the use of shadow in classical art, to the development of perspective during the Renaissance. However, the history of the use of stereoscopic techniques is controversial. Although the first undisputed stereoscopic images were presented by Wheatstone in 1838, it has been claimed that two sketches by Jacopo Chimenti da Empoli (c. 1600) can be to be fused to yield an impression of stereoscopic depth, while others suggest that Leonardo da Vinci's Mona Lisa is the world's first stereogram. Here, we report the first quantitative study of perceived depth in these works, in addition to more recent works by Salvador Dalí. To control for the contribution of monocular depth cues, ratings of the magnitude and coherence of depth were recorded for both stereoscopic and pseudoscopic presentations, with a genuine contribution of stereoscopic cues revealed by a difference between these scores. Although effects were clear for Wheatstone and Dalí's images, no such effects could be found for works produced earlier. As such, we have no evidence to reject the conventional view that the first producer of stereoscopic imagery was Sir Charles Wheatstone.

Integral imaging with multiple image planes using a uniaxial crystal plate.

PubMed

Park, Jae-Hyeung; Jung, Sungyong; Choi, Heejin; Lee, Byoungho

2003-08-11

Integral imaging has been attracting much attention recently for its several advantages such as full parallax, continuous view-points, and real-time full-color operation. However, the thickness of the displayed three-dimensional image is limited to relatively small value due to the degradation of the image resolution. In this paper, we propose a method to provide observers with enhanced perception of the depth without severe resolution degradation by the use of the birefringence of a uniaxial crystal plate. The proposed integral imaging system can display images integrated around three central depth planes by dynamically altering the polarization and controlling both elemental images and dynamic slit array mask accordingly. We explain the principle of the proposed method and verify it experimentally.

Misperceptions of angular velocities influence the perception of rigidity in the kinetic depth effect

NASA Technical Reports Server (NTRS)

Domini, F.; Caudek, C.; Proffitt, D. R.; Kaiser, M. K. (Principal Investigator)

1997-01-01

Accuracy in discriminating rigid from nonrigid motion was investigated for orthographic projections of three-dimension rotating objects. In 3 experiments the hypothesis that magnitudes of angular velocity are misperceived in the kinetic depth effect was tested, and in 4 other experiments the hypothesis that misperceiving angular velocities leads to misperceiving rigidity was tested. The principal findings were (a) the magnitude of perceived angular velocity is derived heuristically as a function of a property of the first-order optic flow called deformation and (b) perceptual performance in discriminating rigid from nonrigid motion is accurate in cases when the variability of the deformations of the individual triplets of points of the stimulus displays favors this interpretation and not accurate in other cases.

Misperceptions of angular velocities influence the perception of rigidity in the kinetic depth effect.

PubMed

Domini, F; Caudek, C; Proffitt, D R

1997-08-01

Accuracy in discriminating rigid from nonrigid motion was investigated for orthographic projections of three-dimension rotating objects. In 3 experiments the hypothesis that magnitudes of angular velocity are misperceived in the kinetic depth effect was tested, and in 4 other experiments the hypothesis that misperceiving angular velocities leads to misperceiving rigidity was tested. The principal findings were (a) the magnitude of perceived angular velocity is derived heuristically as a function of a property of the first-order optic flow called deformation and (b) perceptual performance in discriminating rigid from nonrigid motion is accurate in cases when the variability of the deformations of the individual triplets of points of the stimulus displays favors this interpretation and not accurate in other cases.

Living with cleft lip and palate: the treatment journey.

PubMed

Alansari, Reem; Bedos, Christophe; Allison, Paul

2014-03-01

To better understand how individuals with cleft lip and palate (CLP) perceive and experience their treatment process and how these perceptions and experiences change over the life course. Qualitative in-depth semistructured interviews with 11 adults with nonsyndromal complete CLP. Individuals from three Canadian cities were recruited by convenience and theoretical sampling through AboutFace International. The number of participants was determined by the principle of theoretical saturation. The experience of individuals with CLP through the treatment process changes over the life course. In childhood and early adolescence, most individuals experience stigma, negative self-perception, and as a result were more prone to perceiving the treatment process not only as unbearably burdensome but also as fueling their feeling of "defectiveness." In adulthood, participants' self-perception improved, partly because of definitive surgical correction, leading them to realize treatment benefits and reappraise the treatment process as satisfactory rather than burdensome. Subsequently, some individuals pursued further surgeries hoping for additional psychological gains, in lieu of psychosocial interventions addressing the underpinnings of residual feelings of "defectiveness." This led to dissatisfaction and frustration when the procedures did not lead to the hoped-for psychological gains. The results emphasize the importance of self-perception in determining how participants perceive several important aspects of the treatment experience throughout the life course. Further studies should focus on how to incorporate self-perception as an important variable and outcome in the treatment process.

[Health diagnosis and risk perception: key elements of a proposed intervention for indigenous communities in Mexico].

PubMed

Terán-Hernández, Mónica; Díaz-Barriga, Fernando; Cubillas-Tejeda, Ana Cristina

2016-02-01

Objective To carry out a diagnosis of children's environmental health and an analysis of risk perception in indigenous communities of the Huasteca Sur region of San Luis Potosí, Mexico, in order to design an intervention strategy in line with their needs. Methods The study used mixed methods research, carried out in two phases. It was conducted in three indigenous communities of Tancanhuitz municipality from January 2005 to June 2006. In the adult population, risk perception was analyzed through focus groups, in-depth interviews, and questionnaires. In the child population, analysis of children's drawings was used to study perception. An assessment of health risks was carried out through biological monitoring and environmental monitoring of water and soil. Results The three communities face critical problems that reveal their vulnerability. When the results were triangulated and integrated, it was found that the principal problems relate to exposure to pathogenic microorganisms in water and soil, exposure to indoor wood smoke, exposure to smoke from the burning of refuse, use of insecticides, exposure to lead from the use of glazed ceramics, and alcoholism. Conclusions To ensure that the intervention strategy is adapted to the target population, it is essential to incorporate risk perception analysis and to promote the participation of community members. The proposed intervention strategy to address the detected problems is based on the principles of risk communication, community participation, and interinstitutional linkage.

Parental attitudes towards and perceptions of their children's participation in clinical research: a developing-country perspective.

PubMed

Nabulsi, Mona; Khalil, Yvette; Makhoul, Jihad

2011-07-01

Paediatric clinical research faces unique challenges that compromise optimal recruitment of children into clinical trials. A main barrier to enrolment of children is parental misconceptions about the research process. In developing countries, there is a knowledge gap regarding parental perceptions of and attitudes towards their children's participation in clinical trials. To explore such perceptions and attitudes in Lebanese parents. 33 in-depth interviews were conducted with parents with and without previous research experience. Interviews were tape-recorded, transcribed in colloquial Arabic, and later subjected to thematic analysis. Benefit/risk ratio assessment was a major determinant of parental consent. Fear of adverse events or painful procedures in research was a recurring theme in most interviews. Whereas perception of direct benefit to the child, trust in the physician or institution, financial gains or having a positive previous experience in research facilitated consent, a complex informed consent form and misunderstanding of the term 'randomisation' hindered parental approval of participation. Lebanese parents have perceptions of and attitudes towards children's participation in clinical trials that are similar to those reported from the industrialised world. Improving communication with parents and building trust between researchers and parents is important for successful recruitment. Investigators planning to conduct paediatric trials in developing countries need to simplify consent forms and devise new ways to explain randomisation.

Employer Perceptions of Associate Degrees in Local Labor Markets: A Case Study of the Employment of Information Technology Technicians in Detroit and Seattle. CCRC Working Paper No. 39

ERIC Educational Resources Information Center

Van Noy, Michelle; Jacobs, James

2012-01-01

While promoting postsecondary credential completion is a national priority intended to help graduates secure good jobs, the value of credentials in the labor market from the perspective of employers is not well understood. Specifically, more attention is needed to understand how credentials align with employer needs. Through in-depth interviews…

The Preliminary Findings of a Study Exploring the Perceptions of a Sample of Young Heterosexual Males regarding HIV Prevention Education Programming in Nova Scotia, Canada

ERIC Educational Resources Information Center

Gahagan, Jacqueline; Rehman, Laurene; Barbour, Laura; McWilliam, Susan

2007-01-01

Despite the increasing numbers of young Canadian females becoming infected with HIV through heterosexual transmission with an infected male sexual partner, the majority of current HIV prevention programs and services in Canada continue to ignore the needs of young heterosexual males. This research is derived from 30 in-depth interviews, 9 focus…

Perceptions of Writing by Exceptional Cases of Adult Returning Women in a Rural Community College: Differences between Persisters and Leavers.

ERIC Educational Resources Information Center

Starks, Gretchen

A study was conducted at a rural community college to explore the process by which adult women who had returned to college decided whether to persist or drop out. In-depth interviews were conducted with 17 women who had been identified as exceptional in that they either persisted and graduated even though they had been initially identified as…

The Impact of Early Retirement on Perceptions of Life at Work and at Home: Qualitative Analyses of British Civil Servants Participating in the Whitehall II Retirement Study

ERIC Educational Resources Information Center

Mein, Gill; Ellison, George T. H.

2006-01-01

This study examined pathways to retirement and the role of circumstances at work and at home (including the introduction of financially-enhanced early retirement schemes) on retirement-related decision-making. In-depth qualitative interviews were conducted within 2 years of retirement with 59 British civil servants participating in the Whitehall…

Cytology 3D structure formation based on optical microscopy images

NASA Astrophysics Data System (ADS)

Pronichev, A. N.; Polyakov, E. V.; Shabalova, I. P.; Djangirova, T. V.; Zaitsev, S. M.

2017-01-01

The article the article is devoted to optimization of the parameters of imaging of biological preparations in optical microscopy using a multispectral camera in visible range of electromagnetic radiation. A model for the image forming of virtual preparations was proposed. The optimum number of layers was determined for the object scan in depth and holistic perception of its switching according to the results of the experiment.

The Case of a Self-Contained Elementary Classroom for the Gifted: Student, Teacher, and Parent Perceptions of Existing versus Desired Teaching-Learning Aspects

ERIC Educational Resources Information Center

Vidergor, Hava E.; Azar Gordon, Lea

2015-01-01

This study examined whether a self-contained gifted classroom meets the needs of its learners. Considering the existing and desired aspects, as perceived by students, teachers, and parents, it offers a unique lens forming a holistic in-depth view of the self-contained classroom. Forty-two participants took part in this study: 20 students, 15…

The Online Instructional Dynamic: A Study of Community College Faculty Teaching Online Courses and Their Perceptions of Barriers to Student Success

ERIC Educational Resources Information Center

Hadsell, Jory Andrew

2012-01-01

Online students at some California community colleges are experiencing lower success rates than their peers in face-to-face versions of the same courses. Insight into the forces shaping student success in online courses is needed to address such disparities. The purpose of this study was to explore, in-depth, the lived experiences of faculty…

The Learning Life Course of at "Risk" Children Aged 3-16: Perceptions of Students and Parents about "Succeeding against the Odds"

ERIC Educational Resources Information Center

Siraj-Blatchford, Iram; Mayo, Aziza; Melhuish, Edward; Taggart, Brenda; Sammons, Pamela; Sylva, Kathy

2013-01-01

Understanding how we can support children through their learning life course has become a policy imperative, particularly those children from poor homes who would normally be facing a low achiever trajectory. The paper reports on 50 in-depth Child and Family Case Studies (CFCS) that were conducted as part of the Effective Provision of Pre-School,…

Having It All? A Qualitative Examination of Affluent Adolescent Girls' Perceptions of Stress and Their Quests for Success

ERIC Educational Resources Information Center

Spencer, Renée; Walsh, Jill; Liang, Belle; Mousseau, Angela M. Desilva; Lund, Terese J.

2018-01-01

This study sought to better understand the relationship between affluence and elevated risk for psychosocial distress among adolescent girls. In-depth qualitative interviews at two time points with three cohorts of girls (sixth-, eighth-, and 10th grade; T1 n = 57, T2 n = 58) from two independent girls schools Grades 6 to 12, along with their…

The Influence of Children's Gender and Age on Children's Use of Digital Media at Home

ERIC Educational Resources Information Center

Kucirkova, Natalia; Littleton, Karen; Kyparissiadis, Antonios

2018-01-01

This study is the first to systematically investigate the influence of child gender and age, on parents' perceptions of UK children's digital media use at home. It provides an in-depth exploration of how children's age and gender influence the balance between children's use of digital and non-digital media at home. The data draw on 709 parents'…

Perceptions of Trainers Regarding Their Own Understanding of Children Living in Poverty Arising from Providing Professional Development in "A Framework for Understanding Poverty" to Educators

ERIC Educational Resources Information Center

D'Silva, John T.

2009-01-01

The purpose of this phenomenological study was to explore through in-depth analysis of interviews of perceptual change and what trainers of "A Framework for Understanding Poverty" to educators have learned about themselves, about poverty in the United States, about children of poverty, and about those who work with students of poverty. A…

[The contribution of different cochlear insertion region to Mandarin speech perception in users of cochlear implant].

PubMed

Qi, Beier; Liu, Bo; Liu, Sha; Liu, Haihong; Dong, Ruijuan; Zhang, Ning; Gong, Shusheng

2011-05-01

To study the effect of cochlear electrode coverage and different insertion region on speech recognition, especially tone perception of cochlear implant users whose native language is Mandarin Chinese. Setting seven test conditions by fitting software. All conditions were created by switching on/off respective channels in order to simulate different insertion position. Then Mandarin CI users received 4 Speech tests, including Vowel Identification test, Consonant Identification test, Tone Identification test-male speaker, Mandarin HINT test (SRS) in quiet and noise. To all test conditions: the average score of vowel identification was significantly different, from 56% to 91% (Rank sum test, P < 0.05). The average score of consonant identification was significantly different, from 72% to 85% (ANOVNA, P < 0.05). The average score of Tone identification was not significantly different (ANOVNA, P > 0.05). However the more channels activated, the higher scores obtained, from 68% to 81%. This study shows that there is a correlation between insertion depth and speech recognition. Because all parts of the basement membrane can help CI users to improve their speech recognition ability, it is very important to enhance verbal communication ability and social interaction ability of CI users by increasing insertion depth and actively stimulating the top region of cochlear.

Lighting design for globally illuminated volume rendering.

PubMed

Zhang, Yubo; Ma, Kwan-Liu

2013-12-01

With the evolution of graphics hardware, high quality global illumination becomes available for real-time volume rendering. Compared to local illumination, global illumination can produce realistic shading effects which are closer to real world scenes, and has proven useful for enhancing volume data visualization to enable better depth and shape perception. However, setting up optimal lighting could be a nontrivial task for average users. There were lighting design works for volume visualization but they did not consider global light transportation. In this paper, we present a lighting design method for volume visualization employing global illumination. The resulting system takes into account view and transfer-function dependent content of the volume data to automatically generate an optimized three-point lighting environment. Our method fully exploits the back light which is not used by previous volume visualization systems. By also including global shadow and multiple scattering, our lighting system can effectively enhance the depth and shape perception of volumetric features of interest. In addition, we propose an automatic tone mapping operator which recovers visual details from overexposed areas while maintaining sufficient contrast in the dark areas. We show that our method is effective for visualizing volume datasets with complex structures. The structural information is more clearly and correctly presented under the automatically generated light sources.

Patient perception and the barriers to practicing patient-centered communication: A survey and in-depth interview of Chinese patients and physicians.

PubMed

Ting, Xu; Yong, Bao; Yin, Liang; Mi, Tian

2016-03-01

To investigate patient perceptions of patient-centered communication (PCC) in doctor-patient consultations and explore barriers to PCC implementation in China. This study was conducted in public teaching hospital in Guiyang, Guizhou, China. In Phase 1, patient attitudes to PCC were quantitatively assessed in 317 outpatients using modified Patient-Practitioner Orientation Scale (PPOS). In Phase 2, we conducted in-depth interviews with 20 outpatients to explore their views on PCC and expose potential barriers to PCC implementation. Participants communicated "patient-centered" preferences, particularly with regard to their doctors' empathy, communication skills, time and information sharing. Patients were more concerned about doctors exhibiting caring perspective than power sharing. Younger and highly educated patients were more likely to prefer PCC and highly educated patients paid more attention to power sharing. Several factors including inadequate time for PCC resulting from doctors' high patient-load, doctor-patient communication difficulties and excessive treatment due to inappropriate medical payment system affected PCC implementation in China. Patients expressed moderate enthusiasm for PCC in China. They expressed strong preferences concerning physician respect for patient perspective, but less concern for power sharing. Government should improve health care system by implementing PCC in daily healthcare practice to improve patient awareness and preferences. Copyright © 2016. Published by Elsevier Ireland Ltd.

Perception of spokespersons' performance and characteristics in crisis communication: experience of the 2003 severe acute respiratory syndrome outbreak in Taiwan.

PubMed

Lyu, Shu-Yu; Chen, Ruey-Yu; Wang, Shih-fan Steve; Weng, Ya-Ling; Peng, Eugene Yu-Chang; Lee, Ming-Been

2013-10-01

To explore perception of spokespersons' performance and characteristics in response to the 2003 severe acute respiratory syndrome (SARS) outbreak. This study was conducted from March to July, 2005, using semi-structured in-depth interviews to collect data. All interviews were audio-recorded and transcribed verbatim. A qualitative content analysis was employed to analyze the transcribed data. Interviewees included media reporters, media supervisors, health and medical institution executives or spokespersons, and social observers. Altogether, 35 interviewees were recruited for in-depth interviews, and the duration of the interview ranged from 1 hour to 2 hours. Results revealed that the most important characteristics of health/medical institutions spokespersons are professional competence and good interaction with the media. In contrast, the most important behaviors they should avoid are concealing the truth and misreporting the truth. Three major flaws of spokespersons' performance were identified: they included poor understanding of media needs and landscape; blaming the media to cover up a mistake they made in an announcement; and lack of sufficient participation in decision-making or of authorization from the head of organization. Spokespersons of health and medical institutions play an important role in media relations during the crisis of a newly emerging infectious disease. Copyright © 2013. Published by Elsevier B.V.