Combining visual information from the two eyes: The relationship between isthmotectal cells that project to ipsilateral and to contralateral optic tectum using fluorescent retrograde labels in the frog,Rana pipiens

2007 ◽  
Vol 502 (1) ◽  
pp. 38-54 ◽  
Author(s):  
Elizabeth A. Dudkin ◽  
Joel B. Sheffield ◽  
Edward R. Gruberg
2021 ◽  
Vol 12 ◽  
Author(s):  
Anne Giersch ◽  
Thomas Huard ◽  
Sohee Park ◽  
Cherise Rosen

The experience of oneself in the world is based on sensory afferences, enabling us to reach a first-perspective perception of our environment and to differentiate oneself from the world. Visual hallucinations may arise from a difficulty in differentiating one's own mental imagery from externally-induced perceptions. To specify the relationship between hallucinations and the disorders of the self, we need to understand the mechanisms of hallucinations. However, visual hallucinations are often under reported in individuals with psychosis, who sometimes appear to experience difficulties describing them. We developed the “Strasbourg Visual Scale (SVS),” a novel computerized tool that allows us to explore and capture the subjective experience of visual hallucinations by circumventing the difficulties associated with verbal descriptions. This scale reconstructs the hallucinated image of the participants by presenting distinct physical properties of visual information, step-by-step to help them communicate their internal experience. The strategy that underlies the SVS is to present a sequence of images to the participants whose choice at each step provides a feedback toward re-creating the internal image held by them. The SVS displays simple images on a computer screen that provide choices for the participants. Each step focuses on one physical property of an image, and the successive choices made by the participants help them to progressively build an image close to his/her hallucination, similar to the tools commonly used to generate facial composites. The SVS was constructed based on our knowledge of the visual pathways leading to an integrated perception of our environment. We discuss the rationale for the successive steps of the scale, and to which extent it could complement existing scales.


Author(s):  
Jon Barwise ◽  
John Etchemendy

Psychologists have long been interested in the relationship between visualization and the mechanisms of human reasoning. Mathematicians have been aware of the value of diagrams and other visual tools both for teaching and as heuristics for mathematical discovery. As the chapters in this volume show, such tools are gaining even greater value, thanks in large part to the graphical potential of modern computers. But despite the obvious importance of visual images in human cognitive activities, visual representation remains a second-class citizen in both the theory and practice of mathematics. In particular, we are all taught to look askance at proofs that make crucial use of diagrams, graphs, or other nonlinguistic forms of representation, and we pass on this disdain to our students. In this chapter, we claim that visual forms of representation can be important, not just as heuristic and pedagogic tools, but as legitimate elements of mathematical proofs. As logicians, we recognize that this is a heretical claim, running counter to centuries of logical and mathematical tradition. This tradition finds its roots in the use of diagrams in geometry. The modern attitude is that diagrams are at best a heuristic in aid of finding a real, formal proof of a theorem of geometry, and at worst a breeding ground for fallacious inferences. For example, in a recent article, the logician Neil Tennant endorses this standard view: . . . [The diagram] is only an heuristic to prompt certain trains of inference; . . . it is dispensable as a proof-theoretic device; indeed, . . . it has no proper place in the proof as such. For the proof is a syntactic object consisting only of sentences arranged in a finite and inspectable array (Tennant [1984]). . . . It is this dogma that we want to challenge. We are by no means the first to question, directly or indirectly, the logocentricity of mathematics arid logic. The mathematicians Euler and Venn are well known for their development of diagrammatic tools for solving mathematical problems, and the logician C. S. Peirce developed an extensive diagrammatic calculus, which he intended as a general reasoning tool.


1974 ◽  
Vol 61 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Allen W. Schuetz ◽  
Robin A. Wallace ◽  
James N. Dumont

The relationship between blood protein (vitellogenin) incorporation and nuclear maturation was studied in individual amphibian oocytes after in vitro exposure to desoxycorticosterone acetate (DOCA). Isolated Rana pipiens oocytes were incubated in vitro with radioactively labeled oocyte yolk precursor ([3H]vitellogenin) obtained from estrogenized Xenopus laevis. Incorporation of labeled vitellogenin into the oocytes continued over a 24-h period. Oocytes simultaneously exposed to DOCA and to labeled vitellogenin exhibited both inhibition of vitellogenin incorporation and stimulation of nuclear maturation and cortical changes. Inhibition of vitellogenin incorporation was observed after approximately 9 h of incubation and was correlated with the time of nuclear breakdown. Preincubation of oocytes in steroid for 9 h essentially terminated vitellogenin incorporation. Incorporation of vitellogenin occurred after removal of follicle cells from the oocyte by a short treatment with EDTA. These results demonstrate the macromolecular vitellogenin transport system remains operative in oocytes which can undergo nuclear maturation and that the steroid DOCA can affect its function. Evidence suggests that the mechanism of steroid inhibition is in part the result of inhibition of the micropinocytotic process in the oocyte cortex.


Author(s):  
Baptiste Coudrillier ◽  
Kristin M. Myers ◽  
Thao D. Nguyen

By 2010, 60 million people will have glaucoma, the second leading cause of blindness worldwide [1]. The disease is characterized by a progressive degeneration of the retinal ganglion cells (RGC), a type of neuron that transmits visual information to the brain. It is well know that elevated intraocular pressure (IOP) is a risk factor in the damage to the RGCs [3–5], but the relationship between the mechanical properties of the ocular connective tissue and how it affects cellular function is not well characterized. The cornea and the sclera are collage-rich structures that comprise the outer load-bearing shell of the eye. Their preferentially aligned collagen lamellae provide mechanical strength to resist ocular expansion. Previous uniaxial tension studies suggest that altered viscoelastic material properties of the eye wall play a role in glaucomatous damage [6].


2020 ◽  
Vol 168 (3) ◽  
pp. 213-222
Author(s):  
Yuko Watanabe ◽  
Kazuho Okuya ◽  
Yuki Takada ◽  
Masato Kinoshita ◽  
Saori Yokoi ◽  
...  

Abstract Transglutaminases are an enzyme family that catalyses protein cross-linking essential for several biological functions. In the previous studies, we characterized the orthologues of the mammalian transglutaminase family in medaka (Oryzias latipes), an established fish model. Among the human isozymes, tissue-type transglutaminase (TG2) has multiple functions that are involved in several biological phenomena. In this study, we established medaka mutants deficient for the orthologue of human TG2 using the CRISPR/Cas9 and transcription activator-like effector nucleases systems. Although apparent morphological changes in the phenotype were not observed, movement retardation was found in the mutant fish when evaluated by a tank-diving test. Furthermore, comparative immunohistochemistry analysis using in this fish model revealed that orthologue of human TG2 was expressed at the periventricular layer of the optic tectum. Our findings provide novel insight for the relationship between tissue-type transglutaminase and the nervous system and the associated behaviour.


Author(s):  
Jeffrey C. Joe ◽  
Casey R. Kovesdi ◽  
Andrea Mack ◽  
Tina Miyake

This study examined the relationship between how visual information is organized and people’s visual search performance. Specifically, we systematically varied how visual search information was organized (from well-organized to disorganized), and then asked participants to perform a visual search task involving finding and identifying a number of visual targets within the field of visual non-targets. We hypothesized that the visual search task would be easier when the information was well-organized versus when it was disorganized. We further speculated that visual search performance would be mediated by cognitive workload, and that the results could be generally described by the well-established speed-accuracy tradeoff phenomenon. This paper presents the details of the study we designed and our results.


2008 ◽  
Vol 53 (1) ◽  
pp. 6-25 ◽  
Author(s):  
Nicole Baumgarten

Abstract This article presents an account of the meaning relationship between visual and verbal information in film and the differences between the conventions of making verbal reference to visual information in English films and their German-language versions. The analysis of a diachronic corpus of popular motion pictures and their German-dubbed versions indicates that the film translations ‘handle’ the co-occurring visual information differently than their English source texts. The translations tend to use alternative, non-equivalent, linguistics structures to refer to visual information and insert additional pronominal references and deictic devices, which overtly connect linguistic items to pictorial elements. As a result, the ongoing spoken discourse is explicitly linked with the physical surroundings of the communicative encounter. In contrast, in the English language versions, the relationship between the verbal utterance and the accompanying visual information more often remains lexically implicit. The shifts in translation affect the ideational, interpersonal, and textual meanings expressed in the film texts which, in turn, may result in a variation in the films’ narrative construction and the realization of extralinguistic concepts, such as, for example, gender relations.


2001 ◽  
Vol 18 (3) ◽  
pp. 457-464 ◽  
Author(s):  
ZHENG LI ◽  
KATHERINE V. FITE

Gamma-aminobutyric acid (GABA) is the most prevalent inhibitory neurotransmitter in the vertebrate brain. It can exert its influence either as GABAergic projection pathways or as local interneurons, which play an essential role in many visual functions. However, no GABAergic visual pathways have been studied in frogs so far. In the present study, GABAergic pathways in the central visual system of Rana pipiens were investigated with double-labeling techniques, combining immunocytochemistry for GABA with Rhodamine microspheres for retrograde tracing. Three GABAergic visual pathways were identified: (1) a retino-tectal projection, from retina to the contralateral optic tectum (OT); (2) an ipsilateral projection from the nucleus of the basal optic root (nBOR) to the pretectal nucleus lentiformis mesencephali (nLM); and (3) a second-order pathway from the nucleus isthmi (NI), bilaterally, to the optic tectum. These results indicate that GABA is involved in both first-order (retina to optic tectum) as well as second-order (nucleus isthmi to optic tectum) visual projections in Rana pipiens, and may play a major role in mediating visuomotor reflexs such as optokinetic nystagmus or other visually guided behaviors.


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