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Baldwin AS, Min SH, Alarcon Carrillo S, Wang Z, Cheng Z, Zhou J, Hess RF. Stereo-anomaly is found more frequently in tasks that require discrimination between depths. iScience 2024; 27:109879. [PMID: 38812554 PMCID: PMC11134555 DOI: 10.1016/j.isci.2024.109879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/28/2024] [Accepted: 04/29/2024] [Indexed: 05/31/2024] Open
Abstract
Within the population of humans with otherwise normal vision, there exists some proportion whose ability to perceive depth from binocular disparity is poor or absent. The prevalence of this "stereo-anomaly" has been reported to be as small as 2%, or as great as 30%. We set out to investigate this discrepancy. We used a digital tool to measure stereoacuity in tasks requiring either the detection of disparity or the discrimination of the direction of disparity. In a cohort of 228 participants, we found that 98% were able to consistently perform the detection task. Of these, only 69% consistently performed the discrimination task. The 31% of participants who had difficulty with the discrimination task could further be divided into 17% who were consistently unable to perform the task and 14% who showed limited ability. This suggests that identification of the direction of disparity requires further processing beyond merely detecting its presence.
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Affiliation(s)
- Alex S. Baldwin
- McGill Vision Research, Department of Ophthalmology & Visual Sciences, McGill University, Montreal, QC, Canada
| | - Seung Hyun Min
- McGill Vision Research, Department of Ophthalmology & Visual Sciences, McGill University, Montreal, QC, Canada
| | - Sara Alarcon Carrillo
- McGill Vision Research, Department of Ophthalmology & Visual Sciences, McGill University, Montreal, QC, Canada
| | - Zili Wang
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ziyun Cheng
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jiawei Zhou
- The Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Robert F. Hess
- McGill Vision Research, Department of Ophthalmology & Visual Sciences, McGill University, Montreal, QC, Canada
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Al-Amad SH, Alhammouri QM, Jaser S, Inshasi FK. Association between stereoacuity and simulated clinical performance among dental students: an exploratory investigation. J Dent Educ 2024; 88:418-424. [PMID: 38031318 DOI: 10.1002/jdd.13429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 11/15/2023] [Indexed: 12/01/2023]
Abstract
INTRODUCTION Dentistry is a profession that requires a high level of the hand-eye coordination. Although considerable attention has been put on dental students' manual dexterity, little emphasis was made on students' visual competency as a variable influencing their competency. In this study, we aimed to assess the association between dental students' stereopsis and their pre-clinical performance. METHODS Dental students (n = 49) were required to perform the porcelain-fused-to-crown preparation for a lower first molar and an upper central incisor plastic teeth mounted on phantom heads. Performance was assessed by two faculty members based on two rubrics, which collectively included 11 assessment criteria. Afterward, students undertook a stereoacuity test using Randot stereotest. Stereopsis values greater than 40 arc/s were considered abnormal. RESULTS A significant negative correlation was seen between stereopsis scores and students' grades for the upper incisor (p < 0.01), but not for the lower molar. An association was also seen between abnormal stereopsis and students' poor performance in preparing the finish line of the incisor tooth (p = 0.024). CONCLUSION Abnormal stereopsis can impact dental students' performance, particularly when preparing teeth indirectly using a dental mirror. Dental educators should give attention to students' stereoacuity, in a manner similar to that given to students' manual dexterity.
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Affiliation(s)
| | | | - Sara Jaser
- College of Dental Medicine, University of Sharjah, Sharjah, UAE
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Souchet AD, Lourdeaux D, Burkhardt JM, Hancock PA. Design guidelines for limiting and eliminating virtual reality-induced symptoms and effects at work: a comprehensive, factor-oriented review. Front Psychol 2023; 14:1161932. [PMID: 37359863 PMCID: PMC10288216 DOI: 10.3389/fpsyg.2023.1161932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 05/16/2023] [Indexed: 06/28/2023] Open
Abstract
Virtual reality (VR) can induce side effects known as virtual reality-induced symptoms and effects (VRISE). To address this concern, we identify a literature-based listing of these factors thought to influence VRISE with a focus on office work use. Using those, we recommend guidelines for VRISE amelioration intended for virtual environment creators and users. We identify five VRISE risks, focusing on short-term symptoms with their short-term effects. Three overall factor categories are considered: individual, hardware, and software. Over 90 factors may influence VRISE frequency and severity. We identify guidelines for each factor to help reduce VR side effects. To better reflect our confidence in those guidelines, we graded each with a level of evidence rating. Common factors occasionally influence different forms of VRISE. This can lead to confusion in the literature. General guidelines for using VR at work involve worker adaptation, such as limiting immersion times to between 20 and 30 min. These regimens involve taking regular breaks. Extra care is required for workers with special needs, neurodiversity, and gerontechnological concerns. In addition to following our guidelines, stakeholders should be aware that current head-mounted displays and virtual environments can continue to induce VRISE. While no single existing method fully alleviates VRISE, workers' health and safety must be monitored and safeguarded when VR is used at work.
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Affiliation(s)
- Alexis D. Souchet
- Heudiasyc UMR 7253, Alliance Sorbonne Université, Université de Technologie de Compiègne, CNRS, Compiègne, France
- Institute for Creative Technologies, University of Southern California, Los Angeles, CA, United States
| | - Domitile Lourdeaux
- Heudiasyc UMR 7253, Alliance Sorbonne Université, Université de Technologie de Compiègne, CNRS, Compiègne, France
| | | | - Peter A. Hancock
- Department of Psychology, University of Central Florida, Orlando, FL, United States
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Linton P, Morgan MJ, Read JCA, Vishwanath D, Creem-Regehr SH, Domini F. New Approaches to 3D Vision. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210443. [PMID: 36511413 PMCID: PMC9745878 DOI: 10.1098/rstb.2021.0443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/25/2022] [Indexed: 12/15/2022] Open
Abstract
New approaches to 3D vision are enabling new advances in artificial intelligence and autonomous vehicles, a better understanding of how animals navigate the 3D world, and new insights into human perception in virtual and augmented reality. Whilst traditional approaches to 3D vision in computer vision (SLAM: simultaneous localization and mapping), animal navigation (cognitive maps), and human vision (optimal cue integration) start from the assumption that the aim of 3D vision is to provide an accurate 3D model of the world, the new approaches to 3D vision explored in this issue challenge this assumption. Instead, they investigate the possibility that computer vision, animal navigation, and human vision can rely on partial or distorted models or no model at all. This issue also highlights the implications for artificial intelligence, autonomous vehicles, human perception in virtual and augmented reality, and the treatment of visual disorders, all of which are explored by individual articles. This article is part of a discussion meeting issue 'New approaches to 3D vision'.
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Affiliation(s)
- Paul Linton
- Presidential Scholars in Society and Neuroscience, Center for Science and Society, Columbia University, New York, NY 10027, USA
- Italian Academy for Advanced Studies in America, Columbia University, New York, NY 10027, USA
- Visual Inference Lab, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Michael J. Morgan
- Department of Optometry and Visual Sciences, City, University of London, Northampton Square, London EC1V 0HB, UK
| | - Jenny C. A. Read
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, Tyne & Wear NE2 4HH, UK
| | - Dhanraj Vishwanath
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife KY16 9JP, UK
| | | | - Fulvio Domini
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, RI 02912-9067, USA
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Clayton R, Siderov J. Differences in stereoacuity between crossed and uncrossed disparities reduce with practice. Ophthalmic Physiol Opt 2022; 42:1353-1362. [PMID: 35997266 PMCID: PMC9804356 DOI: 10.1111/opo.13040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/22/2022] [Accepted: 07/22/2022] [Indexed: 01/05/2023]
Abstract
INTRODUCTION Stereoacuity, like many forms of hyperacuity, improves with practice. We investigated the effects of repeated measurements over multiple visits on stereoacuity using two commonly utilised clinical stereotests, for both crossed and uncrossed disparity stimuli. METHODS Participants were adults with normal binocular vision (n = 17) aged between 18 and 50 years. Stereoacuity was measured using the Randot and TNO stereotests on five separate occasions over a six week period. We utilised both crossed and uncrossed stimuli to separately evaluate stereoacuity in both disparity directions. A subset of the subject group also completed a further five visits over an additional six week period. Threshold stereoacuity was determined by the lowest disparity level at which the subjects could correctly identify both the position and disparity direction (crossed or uncrossed) of the stimulus. Data were analysed by repeated measures analysis of variance. RESULTS Stereoacuity for crossed and uncrossed stimuli improved significantly across the first five visits (F1,21 = 4.24, p = 0.05). The main effect of disparity direction on stereoacuity was not significant (F1 = 0.02, p = 0.91). However, a significant interaction between disparity direction and stereotest was identified (F1 = 7.92, p = 0.01). CONCLUSIONS Stereoacuity measured with both the TNO and Randot stereotests improved significantly over the course of five repetitions. Although differences between crossed and uncrossed stereoacuity were evident, they depended on the stereotest used and reduced or disappeared after repeated measurements. A single measure of stereoacuity is inadequate for properly evaluating adult stereopsis clinically.
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Affiliation(s)
- Robin Clayton
- Centre for Vision across the Life Span, Department of Optometry and Vision SciencesUniversity of HuddersfieldHuddersfieldUK
| | - John Siderov
- Centre for Vision across the Life Span, Department of Optometry and Vision SciencesUniversity of HuddersfieldHuddersfieldUK
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Joos L, Jaeger-Honz S, Schreiber F, Keim DA, Klein K. Visual Comparison of Networks in VR. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2022; 28:3651-3661. [PMID: 36048995 DOI: 10.1109/tvcg.2022.3203001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Networks are an important means for the representation and analysis of data in a variety of research and application areas. While there are many efficient methods to create layouts for networks to support their visual analysis, approaches for the comparison of networks are still underexplored. Especially when it comes to the comparison of weighted networks, which is an important task in several areas, such as biology and biomedicine, there is a lack of efficient visualization approaches. With the availability of affordable high-quality virtual reality (VR) devices, such as head-mounted displays (HMDs), the research field of immersive analytics emerged and showed great potential for using the new technology for visual data exploration. However, the use of immersive technology for the comparison of networks is still underexplored. With this work, we explore how weighted networks can be visually compared in an immersive VR environment and investigate how visual representations can benefit from the extended 3D design space. For this purpose, we develop different encodings for 3D node-link diagrams supporting the visualization of two networks within a single representation and evaluate them in a pilot user study. We incorporate the results into a more extensive user study comparing node-link representations with matrix representations encoding two networks simultaneously. The data and tasks designed for our experiments are similar to those occurring in real-world scenarios. Our evaluation shows significantly better results for the node-link representations, which is contrary to comparable 2D experiments and indicates a high potential for using VR for the visual comparison of networks.
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Abstract
Purpose Our visual system compares the inputs received from the two eyes to estimate the relative depths of features in the retinal image. We investigated how an imbalance in the strength of the input received from the two eyes affects stereopsis. We also explored the level of agreement between different measurements of sensory eye imbalance. Methods We measured the sensory eye imbalance and stereoacuity of 30 normally sighted participants. We made our measurements using a modified amblyoscope. The sensory eye imbalance was assessed through three methods: the difference between monocular contrast thresholds, the difference in dichoptic masking weight, and the contribution of each eye to a fused binocular percept. We referred them as the “threshold imbalance,” “masking imbalance,” and “fusion imbalance,” respectively. The stereoacuity threshold was measured by having subjects discriminate which of four circles were displaced in depth. All of our tests were performed using stimuli of the same spatial frequency (2.5 cycles/degree). Results We found a relationship between stereoacuity and sensory eye imbalance. However, this was only the case for fusion imbalance measurement (ρ = 0.52; P = 0.003). Neither the threshold imbalance nor the masking imbalance was significantly correlated with stereoacuity. We also found the threshold imbalance was correlated with both the fusion and masking imbalances (r = 0.46, P = 0.011 and r = 0.49, P = 0.005, respectively). However, a nonsignificant correlation was found between the fusion and masking imbalances. Conclusions Our findings suggest that there exist multiple types of sensory eye dominance that can be assessed by different tasks. We find only imbalances in dominance that result in biases to fused percepts are correlated with stereoacuity.
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Affiliation(s)
- Xi Wang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,Laboratory of Optometry and Vision Sciences, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,McGill Vision Research Unit, Department of Ophthalmology & Visual Sciences, McGill University, Montreal, Quebec, Canada
| | - Alex S Baldwin
- McGill Vision Research Unit, Department of Ophthalmology & Visual Sciences, McGill University, Montreal, Quebec, Canada
| | - Robert F Hess
- McGill Vision Research Unit, Department of Ophthalmology & Visual Sciences, McGill University, Montreal, Quebec, Canada
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Kosovicheva A, Bex PJ. Perceptual effects of unequal saccadic adaptation produced by a dichoptic step. J Vis 2020; 20:7. [PMID: 32428198 PMCID: PMC7409615 DOI: 10.1167/jov.20.5.7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 03/02/2020] [Indexed: 11/24/2022] Open
Abstract
The binocular coordination of eye movements in a three-dimensional environment involves a combination of saccade and vergence movements. To maintain binocular accuracy and control in the face of sensory and motor changes (that occur with e.g., normal aging, surgery, corrective lenses), the oculomotor system must adapt in response to manifest visual errors. This may be achieved through a combination of binocular and monocular mechanisms, including the recalibration of saccade and vergence amplitudes in response to different visual errors induced in each eye (Maiello, Harrison, & Bex, 2016). This work has used a double-step paradigm to recalibrate eye movements in response to visual errors produced by dichoptic target steps (e.g., leftward in the left eye and rightward in the right eye). Here, we evaluated the immediate perceptual effects of this adaptation. Experiment 1 measured localization errors following adaptation by comparing the apparent locations of pre- and postsaccadic probes. Consistent with previous work showing localization errors following saccadic adaptation, our results demonstrated that adaptation to a dichoptic step produces different localization errors in the two eyes. Furthermore, in Experiment 2, this effect was reduced for a vergence shift in the absence of a saccade, indicating that saccade programming is responsible for a large component of this illusory shift. Experiment 3 measured postsaccadic stereopsis thresholds and indicated that, unlike localization judgments, adaptation did not influence stereoacuity. Together, these results demonstrate novel dichoptic visual errors following oculomotor adaptation and point to monocular and binocular mechanisms involved in the maintenance of binocular coordination.
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Affiliation(s)
- Anna Kosovicheva
- Department of Psychology, Northeastern University, Boston, MA, USA
| | - Peter J. Bex
- Department of Psychology, Northeastern University, Boston, MA, USA
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Alarcon Carrillo S, Baldwin AS, Hess RF. Factors limiting sensitivity to binocular disparity in human vision: Evidence from a noise-masking approach. J Vis 2020; 20:9. [PMID: 32232374 PMCID: PMC7405759 DOI: 10.1167/jov.20.3.9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 11/15/2019] [Indexed: 11/24/2022] Open
Abstract
Our visual system uses the disparity between the images received by the two eyes to judge three-dimensional distance to surfaces. We can measure this ability by having subjects discriminate the disparity of rendered surfaces. We wanted to know the basis of the individual differences in this ability. We tested 53 adults with normal vision using a relative disparity detection task. Targets were wedge-shaped surfaces formed from random dots. These were presented in either crossed or uncrossed disparity relative to a random dot background. The threshold disparity ranged from 24 arc seconds in the most-able subject to 275 arc seconds in the least-able subject. There was a small advantage for detecting crossed-disparity targets. We used the noise-masking paradigm to partition subject performance into two factors. These were the subject's equivalent internal noise and their processing efficiency. The parameters were estimated by fitting the linear amplifier model. We found both factors contributed to the individual differences in stereoacuity. Within subjects, those showing an advantage for one disparity direction had enhanced efficiency for that direction. Some subjects had a higher equivalent internal noise for one direction that was balanced out by an increased efficiency. Our approach provides a more thorough account of the stereo-ability of our subjects compared with measuring thresholds alone. We present a normative set of results that can be compared with clinical populations.
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Affiliation(s)
- Sara Alarcon Carrillo
- McGill Vision Research, Department of Ophthalmology & Visual Sciences, McGill University, Montreal, Quebec, Canada
| | - Alex S. Baldwin
- McGill Vision Research, Department of Ophthalmology & Visual Sciences, McGill University, Montreal, Quebec, Canada
| | - Robert F. Hess
- McGill Vision Research, Department of Ophthalmology & Visual Sciences, McGill University, Montreal, Quebec, Canada
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Lockwood P, Blackman A. Visual function assessment of diagnostic radiography students. Radiography (Lond) 2020; 26:e56-e65. [PMID: 32052772 DOI: 10.1016/j.radi.2019.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 10/16/2019] [Accepted: 10/29/2019] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Deterioration of visual acuity (VA) and visual impairment has been linked to age-related subtle changes, gender, and a correlation to socioeconomic status. This study aimed to assess first-year diagnostic radiography students' visual functional abilities by applying the International Classification of Impairments, Disabilities and Handicaps (ICIDH) recommendations of functional VA screening and health-related quality of life questionnaire (HRQOL). METHODS The design followed the World Health Organisation (WHO) electronic VA testing of monocular sight using LogMAR charts and binocular vision using Snellen charts, and an HRQOL questionnaire assessing for reduced ability of visual-based tasks in activities of daily living (ADL). The data was evaluated in correlation to the participant's visual correction, age, gender, and socioeconomic background. RESULTS Seventy students were recruited, all meeting the WHO standard level for visual ability, with 100% (n = 70/70) met or achieved above normal binocular vision, correlating to expected normal population results from published studies for age. The monocular vision demonstrated 74% (n = 52/70) for the right eye, and 80% (n = 56/70) for the left eye for normal vision levels. The results did not differ significantly between each eye (p = 0.21), gender variations between the left eye (p = 0.27) and the right eye (p = 0.10) results were affected by sample ratio of females (80%; n = 56/70) to males (20%; n = 14/70), the visual correction did not impair binocular VA. The HRQOL assessment indicated no significant functional VA issues in the study sample. The study demonstrated no association between the participant's socioeconomic background that may influence their VA ability. CONCLUSION The results provided normative binocular and monocular data on visual function in a sample of student radiographers and indicated that their thresholds align to normal (or near-normal) VA standards. IMPLICATIONS FOR PRACTICE The visual health data was reviewed for subgroup comparison and trend analysis, and did not identify risk factors within this sample group that their VA and visual functioning would impact upon radiography clinical placement tasks and activities. The sample is not generalisable to the wider population; further studies are recommended.
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Affiliation(s)
- P Lockwood
- Medical and Clinical Sciences Research Hub, School of Allied & Public Health Professions, Canterbury Christ Church University, Kent, ME4 4UF, UK.
| | - A Blackman
- Medical and Clinical Sciences Research Hub, School of Allied & Public Health Professions, Canterbury Christ Church University, Kent, ME4 4UF, UK; The Association of British Dispensing Opticians College, Godmersham Park, Godmersham, Canterbury, Kent, CT4 7DT, UK
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Kosovicheva A, Ferreira A, Vera-Diaz FA, Bex PJ. Effects of temporal frequency on binocular deficits in amblyopia. Vision Res 2019; 163:52-62. [PMID: 31404553 PMCID: PMC6726518 DOI: 10.1016/j.visres.2019.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 07/30/2019] [Accepted: 08/05/2019] [Indexed: 12/11/2022]
Abstract
Amblyopia is associated with a range of well-known visual spatial deficits, which include reduced contrast sensitivity, spatial distortions, interocular suppression, and impaired stereopsis. Previous work has also pointed to deficits in processing dynamic visual information, but it is unknown whether these deficits influence performance under binocular conditions. We examined the effects of temporal modulation on contrast sensitivity and binocular interactions in a preliminary study of 8 adults with amblyopia and 14 normally-sighted control subjects. For each observer, we measured interocular balance and stereopsis thresholds with binocular flicker across a range of four temporal (0, 4, 7.5, and 12 Hz) and spatial (1, 2, 4, and 8 cpd) frequencies. Interocular balance was estimated by varying the relative contrast of dichoptic letter pairs to produce perceptual reports of each letter with equal frequency, and stereopsis thresholds were measured by determining the minimum disparity at which subjects identified a front-depth target with 75% accuracy. Consistent with previous findings, we observed greater interocular imbalance and impaired stereoacuity at high spatial frequencies in amblyopes. In contrast, the effects of temporal frequency on performance were smaller: across both groups, interocular imbalance was largest at mid-to-low temporal frequencies, and stereopsis thresholds were unaffected by temporal frequency. Our results suggest that there may be a previously unreported effect of temporal frequency on interocular balance, as well as a possible dissociation between the effects of flicker on interocular balance and stereopsis.
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Affiliation(s)
- Anna Kosovicheva
- Department of Psychology, Northeastern University, 125 Nightingale Hall, 360 Huntington Avenue, Boston, MA 02115, USA.
| | - Adriana Ferreira
- New England College of Optometry, 424 Beacon Street, Boston, MA 02115, USA
| | | | - Peter J Bex
- Department of Psychology, Northeastern University, 125 Nightingale Hall, 360 Huntington Avenue, Boston, MA 02115, USA
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Mitsudo H, Hironaga N, Ogata K, Tobimatsu S. Vertical size disparity induces enhanced neural responses in good stereo observers. Vision Res 2019; 164:24-33. [PMID: 31557605 DOI: 10.1016/j.visres.2019.08.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 08/15/2019] [Accepted: 08/21/2019] [Indexed: 11/16/2022]
Abstract
Stereoscopic three-dimensional vision requires cortical processing for horizontal binocular disparity between the two eyes' retinal images. Behavioral and theoretical studies suggest that vertical size disparity is used to recover the viewing geometry and to generate the slant of a large surface. However, unlike horizontal disparity, the relation between stereopsis and neural responses to vertical disparity remains controversial. To determine the role of cortical processing for vertical size disparity in stereopsis, we measured neuromagnetic responses to disparities in people with good and poor stereopsis, using magnetoencephalography (MEG). Healthy adult participants viewed stereograms with a horizontal or vertical size disparity, and judged the perceived slant of the pattern. We assessed neural activity in response to disparities in the visual cortex and the phase locking of oscillatory responses including the alpha frequency range using MEG. For participants with good stereopsis, activity in the visual areas was significantly higher in response to vertical size disparity than to horizontal size disparity. The time-frequency analysis revealed that early neural responses to vertical size disparity were more phase-locked in good stereo participants than in poor stereo participants. These results provide neuromagnetic evidence that vertical-size disparity processing plays a role in good stereo vision.
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Affiliation(s)
- Hiroyuki Mitsudo
- Division of Psychology, Department of Human Sciences, Faculty of Human-Environment Studies, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.
| | - Naruhito Hironaga
- Department of Clinical Neurophysiology, Neurological Institute, Faculty of Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka 812-8582, Fukuoka, Japan
| | - Katsuya Ogata
- Department of Clinical Neurophysiology, Neurological Institute, Faculty of Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka 812-8582, Fukuoka, Japan
| | - Shozo Tobimatsu
- Department of Clinical Neurophysiology, Neurological Institute, Faculty of Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka 812-8582, Fukuoka, Japan
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Binocular non-stereoscopic cues can deceive clinical tests of stereopsis. Sci Rep 2019; 9:5789. [PMID: 30962466 PMCID: PMC6453951 DOI: 10.1038/s41598-019-42149-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 03/20/2019] [Indexed: 01/14/2023] Open
Abstract
Stereoscopic vision plays a critical role in visual perception; however, it is difficult to assess. In clinical settings, stereoacuity is assessed with clinical stereotests. Observers can use monocular cues to deceive some of the most common stereotests, such as the Titmus test. The Randot test has been found free of monocular cues, and here we confirm that result by testing observers under monocular viewing. However, there is a common misconception that only monocular cues can be used to deceive stereotests. Here we demonstrate that binocular non-stereoscopic cues can also be used to pass the Randot, by testing participants with the test rotated, a condition that abolishes stereopsis, and comparing the performance to a monocular viewing condition. We also assessed the Random Dot Butterfly test and discovered considerable amounts of non-stereoscopic cues, including binocular cues in the Circles that can be used to deceive the test. Participants with amblyopia had more difficulty using non-stereoscopic cues than neurotypical observers. We gathered normal-viewing Randot stereoacuities for 110 participants (90 neurotypical and 20 with amblyopia) and compared them to psychophysical stereoacuities (our gold standard). The Randot test showed low positive normalized predictive values for detecting stereoblindness. It could perfectly detect stereo-impairment but with a low sensitivity.
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Chopin A, Bavelier D, Levi DM. The prevalence and diagnosis of 'stereoblindness' in adults less than 60 years of age: a best evidence synthesis. Ophthalmic Physiol Opt 2019; 39:66-85. [PMID: 30776852 DOI: 10.1111/opo.12607] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/23/2019] [Indexed: 12/21/2022]
Abstract
PURPOSE Stereoscopic vision (or stereopsis) is the ability to perceive depth from binocular disparity - the difference of viewpoints between the two eyes. Interestingly, there are large individual differences as to how well one can appreciate depth from such a cue. The total absence of stereoscopic vision, called 'stereoblindness', has been associated with negative behavioural outcomes such as poor distance estimation. Surprisingly, the prevalence of stereoblindness remains unclear, as it appears highly dependent on the way in which stereopsis is measured. RECENT FINDINGS This review highlights the fact that stereopsis is not a unitary construct, but rather implies different systems. The optimal conditions for measuring these varieties of stereoscopic information processing are discussed given the goal of detecting stereoblindness, using either psychophysical or clinical stereotests. In that light, we then discuss the estimates of stereoblindness prevalence of past studies. SUMMARY We identify four different approaches that all converge toward a prevalence of stereoblindness of 7% (median approach: 7%; unambiguous-stereoblindness-criteria approach: 7%; visual-defect-included approach: 7%; multiple-criteria approach: 7%). We note that these estimates were derived considering adults of age <60 years old. Older adults may have a higher prevalence. Finally, we make recommendations for a new ecological definition of stereoblindness and for efficient clinical methods for determining stereoblindness by adapting existing tools.
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Affiliation(s)
- Adrien Chopin
- Faculte de Psychologie et Sciences de l'Education, University of Geneva, Geneva, Switzerland.,Campus Biotech, Geneva, Switzerland
| | - Daphne Bavelier
- Faculte de Psychologie et Sciences de l'Education, University of Geneva, Geneva, Switzerland.,Campus Biotech, Geneva, Switzerland
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15
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Vancleef K, Serrano-Pedraza I, Sharp C, Slack G, Black C, Casanova T, Hugill J, Rafiq S, Burridge J, Puyat V, Enongue JE, Gale H, Akotei H, Collier Z, Haggerty H, Smart K, Powell C, Taylor K, Clarke MP, Morgan G, Read JCA. ASTEROID: A New Clinical Stereotest on an Autostereo 3D Tablet. Transl Vis Sci Technol 2019; 8:25. [PMID: 30834173 PMCID: PMC6396686 DOI: 10.1167/tvst.8.1.25] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/20/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose To describe a new stereotest in the form of a game on an autostereoscopic tablet computer designed to be suitable for use in the eye clinic and present data on its reliability and the distribution of stereo thresholds in adults. Methods Test stimuli were four dynamic random-dot stereograms, one of which contained a disparate target. Feedback was given after each trial presentation. A Bayesian adaptive staircase adjusted target disparity. Threshold was estimated from the mean of the posterior distribution after 20 responses. Viewing distance was monitored via a forehead sticker viewed by the tablet's front camera, and screen parallax was adjusted dynamically so as to achieve the desired retinal disparity. Results The tablet must be viewed at a distance of greater than ∼35 cm to produce a good depth percept. Log thresholds were roughly normally distributed with a mean of 1.75 log10 arcsec = 56 arcsec and SD of 0.34 log10 arcsec = a factor of 2.2. The standard deviation agrees with previous studies, but ASTEROID thresholds are approximately 1.5 times higher than a similar stereotest on stereoscopic 3D TV or on Randot Preschool stereotests. Pearson correlation between successive tests in same observer was 0.80. Bland-Altman 95% limits of reliability were ±0.64 log10 arcsec = a factor of 4.3, corresponding to an SD of 0.32 log10 arcsec on individual threshold estimates. This is similar to other stereotests and close to the statistical limit for 20 responses. Conclusions ASTEROID is reliable, easy, and portable and thus well-suited for clinical stereoacuity measurements. Translational Relevance New 3D digital technology means that research-quality psychophysical measurement of stereoacuity is now feasible in the clinic.
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Affiliation(s)
- Kathleen Vancleef
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - Ignacio Serrano-Pedraza
- Facultad de Psicología, Universidad Complutense de Madrid, Campus de Somosaguas, Madrid, Spain
| | - Craig Sharp
- School of Computing, Newcastle University, 1 Science Square, Newcastle upon Tyne, UK
| | - Gareth Slack
- School of Computing, Newcastle University, 1 Science Square, Newcastle upon Tyne, UK
| | - Carla Black
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - Therese Casanova
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - Jess Hugill
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - Sheima Rafiq
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - James Burridge
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - Vito Puyat
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - Josee Ewane Enongue
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - Henry Gale
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - Hannah Akotei
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - Zoe Collier
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
| | - Helen Haggerty
- Newcastle Eye Centre, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Trust, Queen Victoria Road, Newcastle upon Tyne, UK
| | - Kathryn Smart
- Newcastle Eye Centre, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Trust, Queen Victoria Road, Newcastle upon Tyne, UK
| | - Christine Powell
- Newcastle Eye Centre, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Trust, Queen Victoria Road, Newcastle upon Tyne, UK
| | - Kate Taylor
- Newcastle Eye Centre, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Trust, Queen Victoria Road, Newcastle upon Tyne, UK
| | - Michael P Clarke
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK.,Newcastle Eye Centre, Royal Victoria Infirmary, Newcastle upon Tyne Hospitals NHS Trust, Queen Victoria Road, Newcastle upon Tyne, UK
| | - Graham Morgan
- School of Computing, Newcastle University, 1 Science Square, Newcastle upon Tyne, UK
| | - Jenny C A Read
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
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16
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Hoffman JJ, Habtamu E, Rono H, Tadesse Z, Wondie T, Minas T, Gashaw B, Callahan EK, MacLeod D, Burton MJ. 3D images as a field grader training tool for trachomatous trichiasis: A diagnostic accuracy study in Ethiopia. PLoS Negl Trop Dis 2019; 13:e0007104. [PMID: 30677024 PMCID: PMC6363231 DOI: 10.1371/journal.pntd.0007104] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 02/05/2019] [Accepted: 12/20/2018] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Trachomatous trichiasis (TT) will continue to develop among those people who have had repeated infections after active trachoma is controlled. Detecting and treating affected individuals will remain necessary for years; a long "tail" of incident cases is anticipated. As the prevalence of TT declines, there will be fewer cases available for training trachoma graders (TG), necessitating alternative methods. METHODOLOGY/PRINCIPAL FINDINGS Prospective, diagnostic accuracy study assessing sensitivity and specificity of 3D and 2D photography as a tool for training TG to detect TT. Individuals with TT in Ethiopia were examined, and 2D and 3D clinical images taken. Images were independently graded by four graders for presence or absence of trichiasis and compared to field grading. We recruited 153 participants. Clinical assessments and images were available for 306 eyes. Trichiasis was identified in 204 eyes by field grading. Image grading was performed on a selection of 262 eyes (131 with trichiasis). Most eyes with trichiasis had minor trichiasis (94/131). Pooled sensitivity was 88.3% (3D) and 98.0% (2D); pooled specificity was 59.8% (3D) and 26.8% (2D). 3D photo grading was 33.0% more specific than the 2D photo grading (p = 0.0002). The overall Kappa scores were 0.48 (3D) and 0.25 (2D). We trained 26 novice TG in Ethiopia using 3D images. They were tested on a 3D images set and had 71.4% agreement (kappa 0.46), relative to an expert. They were then tested examining 50 people, and had 86.8% agreement (kappa 0.75). We also tested 27 experienced TG on the same cases (86.4% agreement, kappa 0.75). There was no difference in performance between groups (p = 0.76). All participants preferred 3D over 2D images for training. CONCLUSIONS/SIGNIFICANCE The slightly higher sensitivity of 2D photos comes at considerable cost in specificity. Training with 3D images enabled novice TG to identify cases as well as experienced TG. 3D were preferred to conventional 2D photos for training. Standardized 3D images of TT could be a useful tool for training TG, in settings where there are now few TT cases.
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Affiliation(s)
- Jeremy J. Hoffman
- International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
| | - Esmael Habtamu
- International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Hillary Rono
- International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Ophthalmology Department, Kitale District Hospital, Kitale, Kenya
| | | | | | | | | | | | - David MacLeod
- Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Matthew J. Burton
- International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
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17
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Microstructural properties of the vertical occipital fasciculus explain the variability in human stereoacuity. Proc Natl Acad Sci U S A 2018; 115:12289-12294. [PMID: 30429321 PMCID: PMC6275509 DOI: 10.1073/pnas.1804741115] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Seeing in the three-dimensional world—stereopsis—is an innate human ability, but it varies substantially among individuals. The neurobiological basis of this variability is not understood. We combined diffusion and quantitative MRI imaging with a psychophysical measurements, and found that variability in stereoacuity is associated with microstructural differences in the right vertical occipital fasciculus, a white matter tract connecting dorsal and ventral visual cortex. This result suggests that the microstructure of the pathways that support information transmission across dorsal and ventral visual areas plays an important role human stereopsis. Stereopsis is a fundamental visual function that has been studied extensively. However, it is not clear why depth discrimination (stereoacuity) varies more significantly among people than other modalities. Previous studies have reported the involvement of both dorsal and ventral visual areas in stereopsis, implying that not only neural computations in cortical areas but also the anatomical properties of white matter tracts connecting those areas can impact stereopsis. Here, we studied how human stereoacuity relates to white matter properties by combining psychophysics, diffusion MRI (dMRI), and quantitative MRI (qMRI). We performed a psychophysical experiment to measure stereoacuity and, in the same participants, we analyzed the microstructural properties of visual white matter tracts on the basis of two independent measurements, dMRI (fractional anisotropy, FA) and qMRI (macromolecular tissue volume; MTV). Microstructural properties along the right vertical occipital fasciculus (VOF), a major tract connecting dorsal and ventral visual areas, were highly correlated with measures of stereoacuity. This result was consistent for both FA and MTV, suggesting that the behavioral–structural relationship reflects differences in neural tissue density, rather than differences in the morphological configuration of fibers. fMRI confirmed that binocular disparity stimuli activated the dorsal and ventral visual regions near VOF endpoints. No other occipital tracts explained the variance in stereoacuity. In addition, the VOF properties were not associated with differences in performance on a different psychophysical task (contrast detection). These series of experiments suggest that stereoscopic depth discrimination performance is, at least in part, constrained by dorso-ventral communication through the VOF.
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18
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Piumsomboon T, Lee GA, Ens B, Thomas BH, Billinghurst M. Superman vs Giant: A Study on Spatial Perception for a Multi-Scale Mixed Reality Flying Telepresence Interface. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2018; 24:2974-2982. [PMID: 30387715 DOI: 10.1109/tvcg.2018.2868594] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The advancements in Mixed Reality (MR), Unmanned Aerial Vehicle, and multi-scale collaborative virtual environments have led to new interface opportunities for remote collaboration. This paper explores a novel concept of flying telepresence for multi-scale mixed reality remote collaboration. This work could enable remote collaboration at a larger scale such as building construction. We conducted a user study with three experiments. The first experiment compared two interfaces, static and dynamic IPD, on simulator sickness and body size perception. The second experiment tested the user perception of a virtual object size under three levels of IPD and movement gain manipulation with a fixed eye height in a virtual environment having reduced or rich visual cues. Our last experiment investigated the participant's body size perception for two levels of manipulation of the IPDs and heights using stereo video footage to simulate a flying telepresence experience. The studies found that manipulating IPDs and eye height influenced the user's size perception. We present our findings and share the recommendations for designing a multi-scale MR flying telepresence interface.
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19
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Wang Y, Cui L, He Z, Lin W, Qu J, Lu F, Zhou J, Hess RF. On the Relationship Between Sensory Eye Dominance and Stereopsis in the Normal-Sighted Adult Population: Normative Data. Front Hum Neurosci 2018; 12:357. [PMID: 30245620 PMCID: PMC6137335 DOI: 10.3389/fnhum.2018.00357] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/20/2018] [Indexed: 01/14/2023] Open
Abstract
The extent of sensory eye dominance, a reflection of the interocular suppression in binocular visual processing, can be quantitatively measured using the binocular phase combination task. In this study, we aimed to provide a normative dataset for sensory eye dominance using this task. Based on that, we also assessed the relationship between perceptual eye dominance and stereopsis. One-hundred and forty-two adults (average age: 24.00 ± 1.74 years old) with normal or corrected to normal monocular visual acuity (logMAR < 0.00) participated. Observer's sensory eye dominance was quantified in two complementary ways: the interocular contrast ratio when the two eyes were balanced (i.e., the balance point) and the absolute value of the binocular perceived phase when each eye viewed maximum contrast stimuli in binocular phase combination task. Stereo acuities were measured with maximum contrast stimuli using an identical spatial frequency (0.30 cycles/degree) and stimulus arrangement to that used in the eye dominance assessment. The averaged balance point was 0.93 ± 0.06 (Mean ± SD), the averaged absolute value of the binocular perceived phase when both eyes viewed maximum contrast stimuli was 7.62 ± 5.91°, and the averaged stereo acuity was 2.19 ± 0.34 log arc seconds. Neither of these two sensory eye dominance measures were significantly correlated with stereo acuity (Balance point: ρ = 0.14, P = 0.10; Phase: ρ = -0.13, P = 0.13). The sensory eye dominance, as reflected using a phase combination task, and stereopsis are not significantly correlated in the normal-sighted population at low spatial frequencies.
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Affiliation(s)
- Yonghua Wang
- Department of Ophthalmology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
- School of Ophthalmology and Optometry and Eye Hospital, and State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Lele Cui
- School of Ophthalmology and Optometry and Eye Hospital, and State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Zhifen He
- School of Ophthalmology and Optometry and Eye Hospital, and State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Wenman Lin
- School of Ophthalmology and Optometry and Eye Hospital, and State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Jia Qu
- School of Ophthalmology and Optometry and Eye Hospital, and State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Fan Lu
- School of Ophthalmology and Optometry and Eye Hospital, and State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Jiawei Zhou
- School of Ophthalmology and Optometry and Eye Hospital, and State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Robert F. Hess
- Department of Ophthalmology, McGill Vision Research, McGill University, Montreal, QC, Canada
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20
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Verhoef BE, Vogels R, Janssen P. Binocular depth processing in the ventral visual pathway. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0259. [PMID: 27269602 DOI: 10.1098/rstb.2015.0259] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2016] [Indexed: 11/12/2022] Open
Abstract
One of the most powerful forms of depth perception capitalizes on the small relative displacements, or binocular disparities, in the images projected onto each eye. The brain employs these disparities to facilitate various computations, including sensori-motor transformations (reaching, grasping), scene segmentation and object recognition. In accordance with these different functions, disparity activates a large number of regions in the brain of both humans and monkeys. Here, we review how disparity processing evolves along different regions of the ventral visual pathway of macaques, emphasizing research based on both correlational and causal techniques. We will discuss the progression in the ventral pathway from a basic absolute disparity representation to a more complex three-dimensional shape code. We will show that, in the course of this evolution, the underlying neuronal activity becomes progressively more bound to the global perceptual experience. We argue that these observations most probably extend beyond disparity processing per se, and pertain to object processing in the ventral pathway in general. We conclude by posing some important unresolved questions whose answers may significantly advance the field, and broaden its scope.This article is part of the themed issue 'Vision in our three-dimensional world'.
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Affiliation(s)
- Bram-Ernst Verhoef
- Laboratorium voor Neuro en Psychofysiologie, KU Leuven, O&N2, Campus Gasthuisberg, 3000 Leuven, Belgium Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA
| | - Rufin Vogels
- Laboratorium voor Neuro en Psychofysiologie, KU Leuven, O&N2, Campus Gasthuisberg, 3000 Leuven, Belgium
| | - Peter Janssen
- Laboratorium voor Neuro en Psychofysiologie, KU Leuven, O&N2, Campus Gasthuisberg, 3000 Leuven, Belgium
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21
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Sakata S, Grove PM, Hill A, Watson MO, Stevenson ARL. Impact of simulated three-dimensional perception on precision of depth judgements, technical performance and perceived workload in laparoscopy. Br J Surg 2017; 104:1097-1106. [PMID: 28425560 PMCID: PMC5485031 DOI: 10.1002/bjs.10528] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 12/16/2016] [Accepted: 02/07/2017] [Indexed: 12/13/2022]
Abstract
Background This study compared precision of depth judgements, technical performance and workload using two‐dimensional (2D) and three‐dimensional (3D) laparoscopic displays across different viewing distances. It also compared the accuracy of 3D displays with natural viewing, along with the relationship between stereoacuity and 3D laparoscopic performance. Methods A counterbalanced within‐subjects design with random assignment to testing sequences was used. The system could display 2D or 3D images with the same set‐up. A Howard–Dolman apparatus assessed precision of depth judgements, and three laparoscopic tasks (peg transfer, navigation in space and suturing) assessed performance (time to completion). Participants completed tasks in all combinations of two viewing modes (2D, 3D) and two viewing distances (1 m, 3 m). Other measures administered included the National Aeronautics and Space Administration Task Load Index (perceived workload) and the Randot® Stereotest (stereoacuity). Results Depth judgements were 6·2 times as precise at 1 m and 3·0 times as precise at 3 m using 3Dversus2D displays (P < 0·001). Participants performed all laparoscopic tasks faster in 3D at both 1 and 3 m (P < 0.001), with mean completion times up to 64 per cent shorter for 3Dversus2D displays. Workload was lower for 3D displays (up to 34 per cent) than for 2D displays at both viewing distances (P < 0·001). Greater viewing distance inhibited performance for two laparoscopic tasks, and increased perceived workload for all three (P < 0·001). Higher stereoacuity was associated with shorter completion times for the navigating in space task performed in 3D at 1 m (r = − 0·40, P = 0·001). Conclusion 3D displays offer large improvements over 2D displays in precision of depth judgements, technical performance and perceived workload. Many advantages for 3D
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Affiliation(s)
- S Sakata
- Schools of Medicine, The University of Queensland, Brisbane, Queensland, Australia.,Department of Colon and Rectal Surgery, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.,Clinical Skills Development Service, Metro North Hospital and Health Service, Brisbane, Queensland, Australia
| | - P M Grove
- Schools of Psychology, The University of Queensland, Brisbane, Queensland, Australia
| | - A Hill
- Schools of Psychology, The University of Queensland, Brisbane, Queensland, Australia.,Clinical Skills Development Service, Metro North Hospital and Health Service, Brisbane, Queensland, Australia
| | - M O Watson
- Schools of Medicine, The University of Queensland, Brisbane, Queensland, Australia.,Schools of Psychology, The University of Queensland, Brisbane, Queensland, Australia.,Clinical Skills Development Service, Metro North Hospital and Health Service, Brisbane, Queensland, Australia
| | - A R L Stevenson
- Schools of Medicine, The University of Queensland, Brisbane, Queensland, Australia.,Department of Colon and Rectal Surgery, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
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22
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Barendregt M, Dumoulin SO, Rokers B. Impaired Velocity Processing Reveals an Agnosia for Motion in Depth. Psychol Sci 2016; 27:1474-1485. [PMID: 27677897 DOI: 10.1177/0956797616663488] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 07/19/2016] [Indexed: 11/16/2022] Open
Abstract
Many individuals with normal visual acuity are unable to discriminate the direction of 3-D motion in a portion of their visual field, a deficit previously referred to as a stereomotion scotoma. The origin of this visual deficit has remained unclear. We hypothesized that the impairment is due to a failure in the processing of one of the two binocular cues to motion in depth: changes in binocular disparity over time or interocular velocity differences. We isolated the contributions of these two cues and found that sensitivity to interocular velocity differences, but not changes in binocular disparity, varied systematically with observers' ability to judge motion direction. We therefore conclude that the inability to interpret motion in depth is due to a failure in the neural mechanisms that combine velocity signals from the two eyes. Given these results, we argue that the deficit should be considered a prevalent but previously unrecognized agnosia specific to the perception of visual motion.
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Affiliation(s)
- Martijn Barendregt
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University .,Department of Experimental and Applied Psychology, Vrije Universiteit Amsterdam
| | - Serge O Dumoulin
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University.,Spinoza Center for Neuroimaging, Amsterdam, The Netherlands
| | - Bas Rokers
- Department of Psychology, University of Wisconsin-Madison.,McPherson Eye Research Institute, University of Wisconsin-Madison
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23
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Feng L, Zhou J, Chen L, Hess RF. Sensory eye balance in surgically corrected intermittent exotropes with normal stereopsis. Sci Rep 2015; 5:13075. [PMID: 26287935 PMCID: PMC4541323 DOI: 10.1038/srep13075] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 07/16/2015] [Indexed: 11/09/2022] Open
Abstract
Surgery to align a deviated or strabismic eye is often done for both functional as well as cosmetic reasons. Although amblyopia is often an impediment to regaining full binocularity in strabismics in general, intermittent exotropes, because their deviation is intermittent, have no amblyopia and some degree of stereopsis. Binocular function, including a balanced ocular dominance, could be expected to be normal after surgical correction if normal levels of stereopsis and visual acuity are postsurgically achieved. Here we used a binocular phase combination paradigm to quantitatively assess the ocular dominance in a group of surgically corrected intermittent exotropes who have normal stereo and visual acuity as defined clinically. Interestingly, we found significant interocular imbalance (balance point < 0.9) in most of the surgically treated patients (8 out 10) but in none of the controls. We conclude that the two eyes may still have a residual sensory imbalance in surgically corrected strabismus even if stereopsis is within normal limits. Our study opens the possibility that a further treatment aimed at re-balancing the ocular dominance might be necessary in surgically treated intermittent exotropia to provide more efficient binocular processing in the long term.
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Affiliation(s)
- Lixia Feng
- Department of Ophthalmology, First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, PR China
| | - Jiawei Zhou
- McGill Vision Research, Dept. Ophthalmology, McGill University, Montreal, PQ, Canada
| | - Li Chen
- Department of Ophthalmology, First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, PR China
| | - Robert F Hess
- McGill Vision Research, Dept. Ophthalmology, McGill University, Montreal, PQ, Canada
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