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Chen Y, You W, Hu Y, Chu H, Chen X, Shi W, Gao X. EEG measurement for the effect of perceptual eye position and eye position training on comitant strabismus. Cereb Cortex 2023; 33:10194-10206. [PMID: 37522301 PMCID: PMC10502583 DOI: 10.1093/cercor/bhad275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 08/01/2023] Open
Abstract
One of the clinical features of comitant strabismus is that the deviation angles in the first and second eye positions are equal. However, there has been no report of consistency in the electroencephalography (EEG) signals between the 2 positions. In order to address this issue, we developed a new paradigm based on perceptual eye position. We collected steady-state visual evoked potentials (SSVEPs) signals and resting-state EEG data before and after the eye position training. We found that SSVEP signals could characterize the suppression effect and eye position effect of comitant strabismus, that is, the SSVEP response of the dominant eye was stronger than that of the strabismus eye in the first eye position but not in the second eye position. Perceptual eye position training could modulate the frequency band activities in the occipital and surrounding areas. The changes in the visual function of comitant strabismus after training could also be characterized by SSVEP. There was a correlation between intermodulation frequency, power of parietal electrodes, and perceptual eye position, indicating that EEG might be a potential indicator for evaluating strabismus visual function.
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Affiliation(s)
- Yuzhen Chen
- Shenzhen International Graduate School, Tsinghua University, Nanshan District, Shenzhen 518055, China
| | - Weicong You
- Shenzhen International Graduate School, Tsinghua University, Nanshan District, Shenzhen 518055, China
| | - Yijun Hu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Haidian District, Beijing 100084, China
| | - Hang Chu
- The National Engineering Research Center for Healthcare Devices, Tianhe District, Guangzhou 510500, China
| | - Xiaogang Chen
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Nankai District, Tianjin 300192, China
| | - Wei Shi
- Department of Ophthalmology, Beijing Children’s Hospital, Capital Medical University, Xicheng District, Beijing 100045, China
| | - Xiaorong Gao
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Haidian District, Beijing 100084, China
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Sunyer-Grau B, Quevedo L, Rodríguez-Vallejo M, Argilés M. Comitant strabismus etiology: extraocular muscle integrity and central nervous system involvement-a narrative review. Graefes Arch Clin Exp Ophthalmol 2023; 261:1781-1792. [PMID: 36680614 PMCID: PMC10271888 DOI: 10.1007/s00417-022-05935-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/09/2022] [Accepted: 12/01/2022] [Indexed: 01/22/2023] Open
Abstract
Strabismus is not a condition in itself but the consequence of an underlying problem. Eye misalignment can be caused by disease, injury, and/or abnormalities in any of the structures and processes involved in visual perception and oculomotor control, from the extraocular muscles and their innervations to the oculomotor and visual processing areas in the brain. A small percentage of all strabismus cases are the consequence of well-described genetic syndromes, acquired insult, or disease affecting the extraocular muscles (EOMs) or their innervations. We will refer to them as strabismus of peripheral origin since their etiology lies in the peripheral nervous system. However, in most strabismus cases, that is comitant, non-restrictive, non-paralytic strabismus, the EOMs and their innervations function properly. These cases are not related to specific syndromes and their precise causes remain poorly understood. They are generally believed to be caused by deficits in the central neural pathways involved in visual perception and oculomotor control. Therefore, we will refer to them as central strabismus. The goal of this narrative review is to discuss the possible causes behind this particular type of eye misalignment and to raise awareness among eyecare professionals about the important role the central nervous system plays in strabismus etiology, and the subsequent implications regarding its treatment. A non-systematic search was conducted using PubMed, Medline, Cochrane, and Google Scholar databases with the keywords "origins," "causes," and "etiology" combined with "strabismus." A snowball approach was also used to find relevant references. In the following article, we will first describe EOM integrity in central strabismus; next, we will address numerous reasons that support the idea of central nervous system (CNS) involvement in the origin of the deviation, followed by listing several possible central causes of the ocular misalignment. Finally, we will discuss the implications CNS etiology has on strabismus treatment.
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Affiliation(s)
- Bernat Sunyer-Grau
- School of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Spain
| | - Lluïsa Quevedo
- School of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Spain
| | | | - Marc Argilés
- School of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Spain
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Ten Tusscher MPM, Houtman AC, De Mey J, Van Schuerbeek P. Cortical Visual Connections via the Corpus Callosum are Asymmetrical in Human Infantile Esotropia. Strabismus 2017; 26:22-27. [PMID: 29279026 DOI: 10.1080/09273972.2017.1418898] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE Besides chiasmal hemidecussation, interhemispheric connections are likely important in human binocularity. The corpus callosum (CC) is the major fiber bundle in the mammalian brain which mostly connects homologous cortical areas in the two hemispheres. Visual interhemispheric connections were found abnormal in strabismic cats. No studies have investigated these pathways in humans with infantile strabismus. METHODS Diffusion tensor imaging was used in four subjects with infantile esotropia (IE) and nine control subjects with normal binocularity, in order to study interhemispheric fibers in the CC connecting the right and left primary visual cortical areas. RESULTS The number of callosal fibers linking both visual cortical areas between the hemispheres was found to be higher in subjects with IE. Also in IE, the amount of visual callosal fibers found after analysis from the primary visual cortical areas on one side appeared significantly different from the amount starting from the contralateral primary visual areas. The distribution area on one side is wider. CONCLUSION We show callosal visual fibers to be abnormal in human IE. Subjects with IE showed abnormal numbers of transcallosal fibers connecting the visual cortical areas on both sides which likely results from an abnormal elimination process during development. Pruning of these fibers in IE favors the side of the visual cortex ipsilateral to the dominant eye. This study underlines the likely role of the CC in the development of human binocularity.
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Affiliation(s)
- Marcel P M Ten Tusscher
- a Department of Ophthalmology , Universitair Ziekenhuis Vrije Universiteit Brussel , Brussels , Belgium
| | - Anne Cees Houtman
- a Department of Ophthalmology , Universitair Ziekenhuis Vrije Universiteit Brussel , Brussels , Belgium
| | - Johan De Mey
- b Department of Radiology , Universitair Ziekenhuis Vrije Universiteit Brussel , Brussels , Belgium
| | - Peter Van Schuerbeek
- b Department of Radiology , Universitair Ziekenhuis Vrije Universiteit Brussel , Brussels , Belgium
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Restani L, Caleo M. Reorganization of Visual Callosal Connections Following Alterations of Retinal Input and Brain Damage. Front Syst Neurosci 2016; 10:86. [PMID: 27895559 PMCID: PMC5107575 DOI: 10.3389/fnsys.2016.00086] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 10/25/2016] [Indexed: 01/16/2023] Open
Abstract
Vision is a very important sensory modality in humans. Visual disorders are numerous and arising from diverse and complex causes. Deficits in visual function are highly disabling from a social point of view and in addition cause a considerable economic burden. For all these reasons there is an intense effort by the scientific community to gather knowledge on visual deficit mechanisms and to find possible new strategies for recovery and treatment. In this review, we focus on an important and sometimes neglected player of the visual function, the corpus callosum (CC). The CC is the major white matter structure in the brain and is involved in information processing between the two hemispheres. In particular, visual callosal connections interconnect homologous areas of visual cortices, binding together the two halves of the visual field. This interhemispheric communication plays a significant role in visual cortical output. Here, we will first review the essential literature on the physiology of the callosal connections in normal vision. The available data support the view that the callosum contributes to both excitation and inhibition to the target hemisphere, with a dynamic adaptation to the strength of the incoming visual input. Next, we will focus on data showing how callosal connections may sense visual alterations and respond to the classical paradigm for the study of visual plasticity, i.e., monocular deprivation (MD). This is a prototypical example of a model for the study of callosal plasticity in pathological conditions (e.g., strabismus and amblyopia) characterized by unbalanced input from the two eyes. We will also discuss the findings of callosal alterations in blind subjects. Noteworthy, we will discuss data showing that inter-hemispheric transfer mediates recovery of visual responsiveness following cortical damage. Finally, we will provide an overview of how callosal projections dysfunction could contribute to pathologies such as neglect and occipital epilepsy. A particular focus will be on reviewing noninvasive brain stimulation techniques and optogenetic approaches that allow to selectively manipulate callosal function and to probe its involvement in cortical processing and plasticity. Overall, the data indicate that experience can potently impact on transcallosal connectivity, and that the callosum itself is crucial for plasticity and recovery in various disorders of the visual pathway.
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Affiliation(s)
- Laura Restani
- Neuroscience Institute, National Research Council (CNR) Pisa, Italy
| | - Matteo Caleo
- Neuroscience Institute, National Research Council (CNR) Pisa, Italy
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Bui Quoc E, Milleret C. Origins of strabismus and loss of binocular vision. Front Integr Neurosci 2014; 8:71. [PMID: 25309358 PMCID: PMC4174748 DOI: 10.3389/fnint.2014.00071] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 08/27/2014] [Indexed: 11/13/2022] Open
Abstract
Strabismus is a frequent ocular disorder that develops early in life in humans. As a general rule, it is characterized by a misalignment of the visual axes which most often appears during the critical period of visual development. However other characteristics of strabismus may vary greatly among subjects, for example, being convergent or divergent, horizontal or vertical, with variable angles of deviation. Binocular vision may also vary greatly. Our main goal here is to develop the idea that such “polymorphy” reflects a wide variety in the possible origins of strabismus. We propose that strabismus must be considered as possibly resulting from abnormal genetic and/or acquired factors, anatomical and/or functional abnormalities, in the sensory and/or the motor systems, both peripherally and/or in the brain itself. We shall particularly develop the possible “central” origins of strabismus. Indeed, we are convinced that it is time now to open this “black box” in order to move forward. All of this will be developed on the basis of both presently available data in literature (including most recent data) and our own experience. Both data in biology and medicine will be referred to. Our conclusions will hopefully help ophthalmologists to better understand strabismus and to develop new therapeutic strategies in the future. Presently, physicians eliminate or limit the negative effects of such pathology both on the development of the visual system and visual perception through the use of optical correction and, in some cases, extraocular muscle surgery. To better circumscribe the problem of the origins of strabismus, including at a cerebral level, may improve its management, in particular with respect to binocular vision, through innovating tools by treating the pathology at the source.
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Affiliation(s)
- Emmanuel Bui Quoc
- Ophthalmology Department, Hopital Robert Debre/Assistance Publique Hopitaux de Paris Paris, France
| | - Chantal Milleret
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB), Spatial Navigation and Memory Team Paris, France
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Tomaiuolo F, Campana S, Collins DL, Fonov VS, Ricciardi E, Sartori G, Pietrini P, Kupers R, Ptito M. Morphometric changes of the corpus callosum in congenital blindness. PLoS One 2014; 9:e107871. [PMID: 25255324 PMCID: PMC4177862 DOI: 10.1371/journal.pone.0107871] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 08/20/2014] [Indexed: 01/18/2023] Open
Abstract
We examined the effects of visual deprivation at birth on the development of the corpus callosum in a large group of congenitally blind individuals. We acquired high-resolution T1-weighted MRI scans in 28 congenitally blind and 28 normal sighted subjects matched for age and gender. There was no overall group effect of visual deprivation on the total surface area of the corpus callosum. However, subdividing the corpus callosum into five subdivisions revealed significant regional changes in its three most posterior parts. Compared to the sighted controls, congenitally blind individuals showed a 12% reduction in the splenium, and a 20% increase in the isthmus and the posterior part of the body. A shape analysis further revealed that the bending angle of the corpus callosum was more convex in congenitally blind compared to the sighted control subjects. The observed morphometric changes in the corpus callosum are in line with the well-described cross-modal functional and structural neuroplastic changes in congenital blindness.
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Affiliation(s)
| | - Serena Campana
- Department of General Psychology, University of Padua, Padua, Italy
| | - D. Louis Collins
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Vladimir S. Fonov
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Emiliano Ricciardi
- Laboratory of Clinical Biochemistry and Molecular Biology, Department of Surgery, Medical, Molecular, and Critical Area Pathology, University of Pisa, Pisa, Italy
- MRI Lab, Fondazione Toscana ‘G. Monasterio’, Pisa, Italy
| | - Giuseppe Sartori
- Department of General Psychology, University of Padua, Padua, Italy
| | - Pietro Pietrini
- Laboratory of Clinical Biochemistry and Molecular Biology, Department of Surgery, Medical, Molecular, and Critical Area Pathology, University of Pisa, Pisa, Italy
- Clinical Psychology Branch, Pisa University Hospital, Pisa, Italy
| | - Ron Kupers
- Harland Sanders Chair in Visual Science, École d’optométrie, Université de Montréal, Montréal, Québec, Canada
- BRAINlab, Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
| | - Maurice Ptito
- Harland Sanders Chair in Visual Science, École d’optométrie, Université de Montréal, Montréal, Québec, Canada
- BRAINlab, Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark
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The corpus callosum and the visual cortex: plasticity is a game for two. Neural Plast 2012; 2012:838672. [PMID: 22792494 PMCID: PMC3388387 DOI: 10.1155/2012/838672] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 04/19/2012] [Indexed: 01/03/2023] Open
Abstract
Throughout life, experience shapes and selects the most appropriate brain functional connectivity to adapt to a changing environment. An ideal system to study experience-dependent plasticity is the visual cortex, because visual experience can be easily manipulated. In this paper, we focus on the role of interhemispheric, transcallosal projections in experience-dependent plasticity of the visual cortex. We review data showing that deprivation of sensory experience can modify the morphology of callosal fibres, thus altering the communication between the two hemispheres. More importantly, manipulation of callosal input activity during an early critical period alters developmental maturation of functional properties in visual cortex and modifies its ability to remodel in response to experience. We also discuss recent data in rat visual cortex, demonstrating that the corpus callosum plays a role in binocularity of cortical neurons and is involved in the plastic shift of eye preference that follows a period of monocular eyelid suture (monocular deprivation) in early age. Thus, experience can modify the fine connectivity of the corpus callosum, and callosal connections represent a major pathway through which experience can mediate functional maturation and plastic rearrangements in the visual cortex.
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Bui Quoc E, Ribot J, Quenech’Du N, Doutremer S, Lebas N, Grantyn A, Aushana Y, Milleret C. Asymmetrical interhemispheric connections develop in cat visual cortex after early unilateral convergent strabismus: anatomy, physiology, and mechanisms. Front Neuroanat 2012; 5:68. [PMID: 22275883 PMCID: PMC3257851 DOI: 10.3389/fnana.2011.00068] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 12/19/2011] [Indexed: 11/13/2022] Open
Abstract
In the mammalian primary visual cortex, the corpus callosum contributes to the unification of the visual hemifields that project to the two hemispheres. Its development depends on visual experience. When this is abnormal, callosal connections must undergo dramatic anatomical and physiological changes. However, data concerning these changes are sparse and incomplete. Thus, little is known about the impact of abnormal postnatal visual experience on the development of callosal connections and their role in unifying representation of the two hemifields. Here, the effects of early unilateral convergent strabismus (a model of abnormal visual experience) were fully characterized with respect to the development of the callosal connections in cat visual cortex, an experimental model for humans. Electrophysiological responses and 3D reconstruction of single callosal axons show that abnormally asymmetrical callosal connections develop after unilateral convergent strabismus, resulting from an extension of axonal branches of specific orders in the hemisphere ipsilateral to the deviated eye and a decreased number of nodes and terminals in the other (ipsilateral to the non-deviated eye). Furthermore this asymmetrical organization prevents the establishment of a unifying representation of the two visual hemifields. As a general rule, we suggest that crossed and uncrossed retino-geniculo-cortical pathways contribute successively to the development of the callosal maps in visual cortex.
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Affiliation(s)
- Emmanuel Bui Quoc
- Laboratoire de Physiologie de la Perception et de l’Action, Collège de FranceParis, France
- Laboratoire de Physiologie de la Perception et de l’Action, CNRS UMR 7152Paris, France
- Service d’Ophtalmologie, Hôpital Robert DebréParis, France
| | - Jérôme Ribot
- Laboratoire de Physiologie de la Perception et de l’Action, Collège de FranceParis, France
- Laboratoire de Physiologie de la Perception et de l’Action, CNRS UMR 7152Paris, France
| | - Nicole Quenech’Du
- Laboratoire de Physiologie de la Perception et de l’Action, Collège de FranceParis, France
- Laboratoire de Physiologie de la Perception et de l’Action, CNRS UMR 7152Paris, France
| | - Suzette Doutremer
- Laboratoire de Physiologie de la Perception et de l’Action, Collège de FranceParis, France
- Laboratoire de Physiologie de la Perception et de l’Action, CNRS UMR 7152Paris, France
| | - Nicolas Lebas
- Laboratoire de Physiologie de la Perception et de l’Action, Collège de FranceParis, France
- Laboratoire de Physiologie de la Perception et de l’Action, CNRS UMR 7152Paris, France
| | - Alexej Grantyn
- Laboratoire de Physiologie de la Perception et de l’Action, Collège de FranceParis, France
- Laboratoire de Physiologie de la Perception et de l’Action, CNRS UMR 7152Paris, France
| | - Yonane Aushana
- Laboratoire de Physiologie de la Perception et de l’Action, Collège de FranceParis, France
- Laboratoire de Physiologie de la Perception et de l’Action, CNRS UMR 7152Paris, France
| | - Chantal Milleret
- Laboratoire de Physiologie de la Perception et de l’Action, Collège de FranceParis, France
- Laboratoire de Physiologie de la Perception et de l’Action, CNRS UMR 7152Paris, France
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Alekseenko SV, Toporova SN, Shkorbatova PY. Interhemisphere connections of eye dominance columns in the cat visual cortex in conditions of impaired binocular vision. ACTA ACUST UNITED AC 2009; 39:489-95. [PMID: 19430981 DOI: 10.1007/s11055-009-9150-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Indexed: 10/20/2022]
Abstract
Data from studies of interhemisphere connections in fields 17 and 18 of cats reared in conditions of impaired binocular vision (monocular deprivation, uni- and bilateral strabismus) are presented. Monosynaptic connections between neurons were studied by microiontophoretic application of horseradish peroxidase into cortical eye dominance columns and the distributions of retrograde labeled callosal cells were analyzed. Spatial asymmetry and eye-specific interhemisphere neuron connections persisted in conditions of monocular deprivation and strabismus. Quantitative changes in connections were less marked in monocular deprivation than strabismus. In cats with impaired binocular vision, as in intact animals, the widths of callosal-receiving zones were greater than the widths of the callosal cell zones, which is evidence for the non-reciprocity of interhemisphere connections in cortical areas distant from the projection of the vertical meridian. Morphofunctional differences between cells mediating connections in the opposite directions are proposed.
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Affiliation(s)
- S V Alekseenko
- I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, 6 Makarov Bank, 199034, St. Petersburg, Russia.
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Milleret C, Houzel JC. Visual interhemispheric transfer to areas 17 and 18 in cats with convergent strabismus. Eur J Neurosci 2001. [DOI: 10.1046/j.1460-9568.2001.01360.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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11
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Milleret C, Houzel JC. Visual interhemispheric transfer to areas 17 and 18 in cats with convergent strabismus. Eur J Neurosci 2001. [DOI: 10.1111/j.1460-9568.2001.01360.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
We have developed a simple computer-based discrimination task that enables the quick determination of visual acuities in rodents. A grating is displayed randomly on one of two monitors at the wide end of a trapezoidal-shaped tank containing shallow water. Animals are trained to swim toward the screens, and at a fixed distance, choose the screen displaying the grating and escape to a submerged platform hidden below it. Both mice and rats learn the task quickly. Performance falls below 70% when the spatial frequency is increased beyond 0.5 cycles in most C57BU6 mice, and around 1.0 cycles per degree (cpd) in Long-Evans rats.
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Affiliation(s)
- G T Prusky
- Department of Psychology and Neuroscience, The University of Lethbridge, 4401 University Drive, AB, TIK 3M4, Lethbridge, Canada.
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Abstract
Strabismus induced early in the life of cats results in disruption of the normal development of the posterior corpus callosum. In human strabismic amblyopic subjects a similar disruption in callosal development may cause poor interhemispheric integration of simple visual information. To examine this possibility judgements of visual target onset precedence were made for targets presented in bilateral and unilateral viewing conditions using a method of constants psychophysical procedure. In one condition, with targets presented in opposite visual fields requiring integration between the two hemispheres, the subjects having strabismic amblyopia had significantly larger just noticeable difference values (JNDs) than those found for the non-strabismic controls. In a second condition, with targets presented within a visual field requiring integration within only a single hemisphere, the JNDs for the two groups were not significantly different. The results suggest that strabismic amblyopes have poor integration of visual information between the cerebral hemispheres, and that this reflects disruptions in the development of the posterior corpus callosum.
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Affiliation(s)
- R St John
- Department of Military Psychology and Leadership, Royal Military College, Kingston, Ontario, Canada.
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