scholarly journals The Language of Vision*

Perception ◽  
2021 ◽  
pp. 030100662199149
Author(s):  
Patrick Cavanagh

The descriptions of surfaces, objects, and events computed by visual processes are not solely for consumption in the visual system but are meant to be passed on to other brain centers. Clearly, the description of the visual scene cannot be sent in its entirety, like a picture or movie, to other centers, as that would require that each of them have their own visual system to decode the description. Some very compressed, annotated, or labeled version must be constructed that can be passed on in a format that other centers—memory, language, planning—can understand. If this is a “visual language,” what is its grammar? In a first pass, we see, among other things, differences in processing of visual “nouns,” visual “verbs,” and visual “prepositions.” Then we look at recursion and errors of visual grammar. Finally, the possibility of a visual language also raises the question of the acquisition of its grammar from the visual environment and the chance that this acquisition process was borrowed and adapted for spoken language.

Author(s):  
Mark Edwards ◽  
Stephanie C. Goodhew ◽  
David R. Badcock

AbstractThe visual system uses parallel pathways to process information. However, an ongoing debate centers on the extent to which the pathways from the retina, via the Lateral Geniculate nucleus to the visual cortex, process distinct aspects of the visual scene and, if they do, can stimuli in the laboratory be used to selectively drive them. These questions are important for a number of reasons, including that some pathologies are thought to be associated with impaired functioning of one of these pathways and certain cognitive functions have been preferentially linked to specific pathways. Here we examine the two main pathways that have been the focus of this debate: the magnocellular and parvocellular pathways. Specifically, we review the results of electrophysiological and lesion studies that have investigated their properties and conclude that while there is substantial overlap in the type of information that they process, it is possible to identify aspects of visual information that are predominantly processed by either the magnocellular or parvocellular pathway. We then discuss the types of visual stimuli that can be used to preferentially drive these pathways.


2017 ◽  
Vol 117 (2) ◽  
pp. 566-581 ◽  
Author(s):  
James C. Dooley ◽  
Michaela S. Donaldson ◽  
Leah A. Krubitzer

The functional organization of the primary visual area (V1) and the importance of sensory experience in its normal development have been well documented in eutherian mammals. However, very few studies have investigated the response properties of V1 neurons in another large class of mammals, or whether sensory experience plays a role in shaping their response properties. Thus we reared opossums ( Monodelphis domestica) in normal and vertically striped cages until they reached adulthood. They were then anesthetized using urethane, and electrophysiological techniques were used to examine neuronal responses to different orientations, spatial and temporal frequencies, and contrast levels. For normal opossums, we observed responses to the temporal and spatial characteristics of the stimulus to be similar to those described in small, nocturnal, eutherian mammals such as rats and mice; neurons in V1 responded maximally to stimuli at 0.09 cycles per degree and 2.12 cycles per second. Unlike other eutherians, but similar to other marsupials investigated, only 40% of the neurons were orientation selective. In stripe-reared animals, neurons were significantly more likely to respond to vertical stimuli at a wider range of spatial frequencies, and were more sensitive to gratings at lower contrast values compared with normal animals. These results are the first to demonstrate experience-dependent plasticity in the visual system of a marsupial species. Thus the ability of cortical neurons to alter their properties based on the dynamics of the visual environment predates the emergence of eutherian mammals and was likely present in our earliest mammalian ancestors.NEW & NOTEWORTHY These results are the first description of visual response properties of the most commonly studied marsupial model organism, the short-tailed opossum ( Monodelphis domestica). Further, these results are the first to demonstrate experience-dependent plasticity in the visual system of a marsupial species. Thus the ability of cortical neurons to alter their properties based on the dynamics of the visual environment predates the emergence of eutherian mammals and was likely present in our earliest mammalian ancestors.


2008 ◽  
Vol 35 (3) ◽  
pp. 342-384 ◽  
Author(s):  
Andrew R. Linn

Summary The major claim of this article is that there is an independent and clearly defined chapter in the development of linguistics, beginning in the 1880s, which represents the birth of modern applied linguistics, and which has been overlooked in linguistic historiography because of the comparative marginalisation of applied linguistics in the literature. This is the Anglo-Scandinavian School, a phrase its members used to describe themselves. Pioneers within phonetics, these linguists applied their phonetic knowledge to a range of ‘real world’ language issues, notably language-teaching reform, orthographic reform, language planning, and the study of the spoken language. As well as presenting the ideas of the Anglo-Scandinavian School and how they were developed, this article interrogates the notion of a school in intellectual history and proposes that it may in fact be more fruitful to view intellectual history in terms of discourse communities.


2006 ◽  
Author(s):  
Ryo Tsuji ◽  
Tomohiko Kasami ◽  
Shogo Ishikawa ◽  
Shinya Kiriyama ◽  
Yoichi Takebayashi ◽  
...  

2018 ◽  
Vol 150 (3) ◽  
pp. 383-388 ◽  
Author(s):  
Edward N. Pugh

Vertebrate rod photoreceptors evolved the astonishing ability to respond reliably to single photons. In parallel, the proximate neurons of the visual system evolved the ability to reliably encode information from a few single-photon responses (SPRs) as arising from the presence of an object of interest in the visual environment. These amazing capabilities were first inferred from measurements of human visual threshold by Hecht et al. (1942), whose paper has since been cited over 1,000 times. Subsequent research, in part inspired by Hecht et al.’s discovery, has directly measured rod SPRs, characterized the molecular mechanism responsible for their generation, and uncovered much about the specializations in the retina that enable the reliable transmission of SPRs in the teeth of intrinsic neuronal noise.


2019 ◽  
Author(s):  
Jack Lindsey ◽  
Samuel A. Ocko ◽  
Surya Ganguli ◽  
Stephane Deny

AbstractThe vertebrate visual system is hierarchically organized to process visual information in successive stages. Neural representations vary drastically across the first stages of visual processing: at the output of the retina, ganglion cell receptive fields (RFs) exhibit a clear antagonistic center-surround structure, whereas in the primary visual cortex (V1), typical RFs are sharply tuned to a precise orientation. There is currently no unified theory explaining these differences in representations across layers. Here, using a deep convolutional neural network trained on image recognition as a model of the visual system, we show that such differences in representation can emerge as a direct consequence of different neural resource constraints on the retinal and cortical networks, and for the first time we find a single model from which both geometries spontaneously emerge at the appropriate stages of visual processing. The key constraint is a reduced number of neurons at the retinal output, consistent with the anatomy of the optic nerve as a stringent bottleneck. Second, we find that, for simple downstream cortical networks, visual representations at the retinal output emerge as nonlinear and lossy feature detectors, whereas they emerge as linear and faithful encoders of the visual scene for more complex cortical networks. This result predicts that the retinas of small vertebrates (e.g. salamander, frog) should perform sophisticated nonlinear computations, extracting features directly relevant to behavior, whereas retinas of large animals such as primates should mostly encode the visual scene linearly and respond to a much broader range of stimuli. These predictions could reconcile the two seemingly incompatible views of the retina as either performing feature extraction or efficient coding of natural scenes, by suggesting that all vertebrates lie on a spectrum between these two objectives, depending on the degree of neural resources allocated to their visual system.


Ophthalmology ◽  
2018 ◽  
pp. 98-114
Author(s):  
Anwesha Banerjee ◽  
Ankita Mazumder ◽  
Poulami Ghosh ◽  
D. N. Tibarewala

We the human beings are blessed by the nature to become well competent for performing highly precise and copious visual processes with how ever a restricted field of view. Howbeit, this process of visual perception is, to a great extent, controlled by the saccades or more commonly the eye movements. The positioning and accommodation of eyes allows an image to be placed (or fixed) in the fovea centralis of the eyes but although we do so to fix our gaze at a particular object, our eyes continuously move. Even though these fixational eye movements includes magnitude that should make them visible to us yet we remain oblivious to them. Microsacades, drifts and tremors that occurs frequently during fixational eye movements, contribute largely to the visual perception. We use saccades several times per second to move the fovea between points of interest and build an understanding of our visual environment.


2018 ◽  
Vol 71 (5) ◽  
pp. 1090-1099 ◽  
Author(s):  
Ryoichi Nakashima ◽  
Takatsune Kumada

When perceiving the visual environment, people simultaneously perceive their own direction and position in the environment (i.e., egocentric spatial perception). This study investigated what visual information in a scene is necessary for egocentric spatial perceptions. In two perception tasks (the egocentric direction and position perception tasks), observers viewed two static road images presented sequentially. In Experiment 1, the critical manipulation involved an occluded region in the road image, an extrapersonal region (far-occlusion) and a peripersonal region (near-occlusion). Egocentric direction perception was worse in the far-occlusion condition than in the no-occlusion condition, and egocentric position perceptions were worse in the far- and near-occlusion conditions than in the no-occlusion condition. In Experiment 2, we conducted the same tasks manipulating the observers’ gaze location in a scene—an extrapersonal region (far-gaze), a peripersonal region (near-gaze) and the intermediate region between the former two (middle-gaze). Egocentric direction perception performance was the best in the far-gaze condition, and egocentric position perception performances were not different among gaze location conditions. These results suggest that egocentric direction perception is based on fine visual information about the extrapersonal region in a road landscape, and egocentric position perception is based on information about the entire visual scene.


2013 ◽  
Vol 325-326 ◽  
pp. 1783-1786
Author(s):  
Yong Jun Chen ◽  
Jun Han

With the rapid development of internet electronic media, the whole environment of modern visual system is in a dynamic and changeable state, so there are limits for those constant and static logos. However, the animation logo will adapt to the dynamic and changeable modern visual environment due to its changeable and polynary form, especially, it is the optimal logo form for the modern internet electronic media; if combined with the operation of creative industry, it would rapidly spread the brand and extremely boost up the brand, and create tremendous influence while putting the brand in a very good status.


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