Discrimination Between Movements of Eye and Object by Visual Interneurones of Crickets

1969 ◽  
Vol 50 (3) ◽  
pp. 723-732
Author(s):  
JOHN PALKA
Keyword(s):  
Eye Movement ◽  
Voluntary Movement ◽  
Compound Eye ◽  
Visual Fields ◽  
Object Motion ◽  
Visual Environment ◽  
Inhibitory Mechanism ◽  
Object Movement ◽  
Moving Stimulus ◽  
Homogeneous Environment

1. One large neurone on each side of the cervical and thoracic ventral nerve cord of crickets responds to object motion anywhere in the visual field of the ipsilateral compound eye, but not to the forced or voluntary movement of the eye itself. 2. This discrimination between self-movement and object-movement is accomplished by an inhibitory mechanism mediated by the same eye. 3. Inhibition must be present because a potent moving stimulus becomes ineffective if presented during a forced eye movement. 4. Its visual origin is demonstrated in two ways: (a) abolishing all known mechanosensory feedback does not disrupt the mechanism, but (b) alteration of visual conditions does so in a predictable way. Sweeping the eye past a complex visual environment suppresses the neurone's response to a concurrently or subsequently presented moving target, whereas the same movement past a simplified or homogeneous environment produces little or no inhibition. 5. Responses to eye movement itself are greatly enhanced in appropriately simplified visual fields, reinforcing the conclusion that the inhibition preventing response in complex fields is of visual origin. 6. Suggestive evidence for an additional inhibitory mechanism associated with voluntary movement is presented.

Visual Field Accuracy and Eye Movement Direction: A Child's Eye View

1980 ◽  
Vol 50 (2) ◽  
pp. 631-636
Author(s):  
Evans Mandes
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Eye Movement ◽  
Visual Fields ◽  
Movement Direction

Post-exposural eye movements were studied in 32 adults and 24 7-yr.-old children. Stimuli were binary figures exposed tachistoscopically in both visual fields simultaneously. The data showed significant correlations between direction of eye movement and locus of recognition for both children and adults. No significant differences were found in frequencies of eye movements of children and adults. The data are interpreted in terms of the facilitative effects of post-exposural eye movements upon perception for both groups.

scholarly journals Video Environmental Assessment of the Administrative Regions Within Urbgeosystem Territories

2019 ◽  
Keyword(s):  
Housing Stock ◽  
Physiological State ◽  
Video Recording ◽  
Visual Fields ◽  
Urban Ecosystem ◽  
Visual Observation ◽  
Visual Environment ◽  
Visual Elements ◽  
The Brain

Purpose. Assess the visual environment of the Novobavarskiy district within Kharkiv urban ecosystem. Methods. Field-based visual observation, photophixation and video recording, statistical. Results. We used a five-point scale to assess the "attractiveness" of territories and objects regarding the psycho-physiological state of a person to determine the quality of the visual environment of Novobavarskiy district, Kharkiv. As a result of video-environmental studies, it was discovered that there are homogeneous and aggressive fields in the visual environment on the territory of Kharkiv. In most cases the aesthetics of the district architecture has a neutral character, bacause a significant number of buildings does not have a variety of visual elements, so as homogeneous and aggressive areas can be found in great variety. It is determined that in the district there are 36% of comfortable visual fields, 13% are homogeneous and 51% are aggressive visual fields. Recently, there has been positive dynamics in the formation of a comfortable visual environment of the district's housing stock. When building new houses and renovating old buildings, different colours for facades are used. The interior is filled with attractive children's playgrounds and green spaces which transforms the aggressive and homogeneous fields of the visual environment into a comfortable one. Conclusions. The situation shows that it is necessary to create a comfortable visual environment that is not represented sufficiently in this district. In this case, there is a real threat to the physiological functions of the brain regarding the perception of information about the visual environment. And in the future it is also necessary to solve these problems using technologies that have been tested and implemented successfully in European countries.

A Woman With Subacute Painful Vision Loss

2021 ◽  
pp. 3-6
Author(s):  
Jiraporn Jitprapaikulsan ◽  
M. Tariq Bhatti ◽  
Eric R. Eggenberger ◽  
Marie D. Acierno ◽  
John J. Chen
Keyword(s):  
Optic Neuritis ◽  
Eye Movement ◽  
Immunoglobulin G ◽  
Vision Loss ◽  
Visual Fields ◽  
Corticosteroid Treatment ◽  
Antineutrophil Cytoplasmic Antibody ◽  
Myelin Oligodendrocyte Glycoprotein ◽  
Intravenous Methylprednisolone ◽  
Eye Pain

A 51-year-old White woman sought care for vision loss 1 week after a nonspecific upper respiratory tract infection. She reported pain in both eyes exacerbated by eye movement, which lasted for several days, followed by bilateral vision loss to the level of counting fingers–only vision. Optic neuritis was diagnosed, and she was treated with 1 g intravenous methylprednisolone for 3 days. Her vision improved substantially, and the pain resolved during the corticosteroid treatment. However, 1 week later, she woke up with right eye pain and vision loss. She was again treated with 5 days of intravenous methylprednisolone, with visual improvement nearly back to baseline. Two weeks later, she had recurrence of painful vision loss in both eyes. A diagnosis of chronic relapsing inflammatory optic neuropathy was made. Tests for serum angiotensin-converting enzyme, antineutrophil cytoplasmic antibody, antinuclear antibody, Lyme disease, syphilis, tuberculosis, and aquaporin-4-immunoglobulin G antibodies were negative. Serum was definitively positive for myelin oligodendrocyte glycoprotein-immunoglobulin G antibodies at a titer of 1:1,000. Myelin oligodendrocyte glycoprotein-immunoglobulin G–associated recurrent optic neuritis was diagnosed. After her diagnosis of recurrent corticosteroid-dependent optic neuritis associated with myelin oligodendrocyte glycoprotein-immunoglobulin G positivity, the patient was treated with 5 days of intravenous methylprednisolone. The eye pain resolved, and her vision returned to normal. At follow-up evaluation, the patient’s visual acuity, color vision, and visual fields were normal in both eyes, but there was mild bilateral optic disc pallor. She has not had recurrent demyelinating episodes while on chronic immunotherapy. Optic neuritis is an inflammatory demyelination of the optic nerve manifesting as acute to subacute vision loss, classically associated with pain with eye movement. The long-term prevention and prognosis depend on the cause of the optic neuritis.

A looming-sensitive pathway responds to changes in the trajectory of object motion

2012 ◽  
Vol 108 (4) ◽  
pp. 1052-1068 ◽  
Author(s):  
Glyn A. McMillan ◽  
John R. Gray
Keyword(s):  
Visual Field ◽  
Firing Rate ◽  
Visual Motion ◽  
Compound Eye ◽  
Angular Acceleration ◽  
Leading Edge ◽  
Object Motion ◽  
Near Miss ◽  
Movement Detector ◽  
Contralateral Movement

Two identified locust neurons, the lobula giant movement detector (LGMD) and its postsynaptic partner, the descending contralateral movement detector (DCMD), constitute one motion-sensitive pathway in the visual system that responds preferentially to objects that approach on a direct collision course and are implicated in collision-avoidance behavior. Previously described responses to the approach of paired objects and approaches at different time intervals (Guest BB, Gray JR. J Neurophysiol 95: 1428–1441, 2006) suggest that this pathway may also be affected by more complicated movements in the locust's visual environment. To test this possibility we presented stationary locusts with disks traveling along combinations of colliding (looming), noncolliding (translatory), and near-miss trajectories. Distinctly different responses to different trajectories and trajectory changes demonstrate that DCMD responds to complex aspects of local visual motion. DCMD peak firing rates associated with the time of collision remained relatively invariant after a trajectory change from translation to looming. Translatory motion initiated in the frontal visual field generated a larger peak firing rate relative to object motion initiated in the posterior visual field, and the peak varied with simulated distance from the eye. Transition from translation to looming produced a transient decrease in the firing rate, whereas transition away from looming produced a transient increase. The change in firing rate at the time of transition was strongly correlated with unique expansion parameters described by the instantaneous angular acceleration of the leading edge and subtense angle of the disk. However, response time remained invariant. While these results may reflect low spatial resolution of the compound eye, they also suggest that this motion-sensitive pathway may be capable of monitoring dynamic expansion properties of objects that change the trajectory of motion.

scholarly journals Representation of the Ipsilateral Visual Field by Neurons in the Macaque Lateral Intraparietal Cortex Depends on the Forebrain Commissures

2010 ◽  
Vol 104 (5) ◽  
pp. 2624-2633 ◽  
Author(s):  
Catherine A. Dunn ◽  
Carol L. Colby
Keyword(s):  
Receptive Field ◽  
Eye Movement ◽  
Visual Information ◽  
Visual Fields ◽  
Receptive Fields ◽  
Neural Mechanism ◽  
Brain Regions ◽  
Spatial Updating ◽  
Split Brain ◽  
Lateral Intraparietal Cortex

Our eyes are constantly moving, allowing us to attend to different visual objects in the environment. With each eye movement, a given object activates an entirely new set of visual neurons, yet we perceive a stable scene. One neural mechanism that may contribute to visual stability is remapping. Neurons in several brain regions respond to visual stimuli presented outside the receptive field when an eye movement brings the stimulated location into the receptive field. The stored representation of a visual stimulus is remapped, or updated, in conjunction with the saccade. Remapping depends on neurons being able to receive visual information from outside the classic receptive field. In previous studies, we asked whether remapping across hemifields depends on the forebrain commissures. We found that, when the forebrain commissures are transected, behavior dependent on accurate spatial updating is initially impaired but recovers over time. Moreover, neurons in lateral intraparietal cortex (LIP) continue to remap information across hemifields in the absence of the forebrain commissures. One possible explanation for the preserved across-hemifield remapping in split-brain animals is that neurons in a single hemisphere could represent visual information from both visual fields. In the present study, we measured receptive fields of LIP neurons in split-brain monkeys and compared them with receptive fields in intact monkeys. We found a small number of neurons with bilateral receptive fields in the intact monkeys. In contrast, we found no such neurons in the split-brain animals. We conclude that bilateral representations in area LIP following forebrain commissures transection cannot account for remapping across hemifields.

Organization of monkey superior colliculus: intermediate layer cells discharging before eye movements

1976 ◽  
Vol 39 (4) ◽  
pp. 722-744 ◽  
Author(s):  
C. W. Mohler ◽  
R. H. Wurtz
Keyword(s):  
Eye Movements ◽  
Superior Colliculus ◽  
Eye Movement ◽  
Intermediate Layer ◽  
Visual Fields ◽  
Saccadic Eye Movements ◽  
Superficial Layer ◽  
Cell Discharge ◽  
Intermediate Layers ◽  
Dorsal Edge

1. We investigated the characteristics of cells in the intermediate layers of the superior colliculus that increase their rate of discharge before saccadic eye movements. Eye movements were repeatedly elicited by training rhesus monkeys to fixate on a spot of light and to make saccades to other spots of light when the fixation spot was turned off. 2. The eye movement cells showed consistent variations with their depth within the colliculus. The onset of the cell discharge led the eye movement by less time and the duration of the discharge was shorter as the cell was located closer to the dorsal edge of the intermediate layers. The movements fields (that area of the visual field where a saccade into the area is preceded by a burst of cell discharges) of each successive cell also became smaller as the cells were located more dorsally. The profile of peak discharge frequency remained fairly flat throughout the movement field of the cells regardless of depth of the cell within the colliculus. 3. A new type of eye movement-related cell has been found which usually lies at the border between the superficial and intermediate layers. This cell type, the visually triggered movement cell, increased its rate of discharge before saccades made to a visual stimulus but not before spontaneous saccades of equal amplitude made in the light or the dark. A vigorous discharge of these cells before an eye movement was dependent on the presence of a visual target; the cells seemed to combine the visual input of superficial layer cells and the movement-related input of the intermediate layer cells. The size of the movement fields of these cells were about the same size as the visual fields of superficial layer cells just above them...

scholarly journals THE EVALUATION OF VISUAL INFLUENCES ON THE ENVIRONMENT OF IVANO-FRANKIVSK CITY

2018 ◽  
pp. 44-51
Author(s):  
T. V. Kundelska ◽  
M. T. Mykytsei
Keyword(s):  
Urban Areas ◽  
Visual Fields ◽  
Urban System ◽  
Waste Utilization ◽  
Urban Systems ◽  
Evaluation Procedure ◽  
Visual Environment ◽  
Visual Evaluation ◽  
Normative Documents ◽  
Visual Impact

The article deals with the problems of urban systems visual contamination which is connected with the issues of noise and electromagnetic loading, waste utilization and storage, water resources pollution, and which depends entirely on the environmental situation within the cities. The paper analyzes Ukrainian and foreign publications on the factors of visual evaluation, particularly the calculation of the coefficient of videoecological susceptibility of the territory, the statistical analysis of visual pollution estimation based on the poll of the respondents who are exposed to negative visual impact. The authors reveal that in Ukraine there are no normative documents which regulate the procedure for the estimation of visual contamination. The article presents the main drawbacks and unresolved parts of the general problem of visual impact evaluation. The authors of the publication suggest a generalized method for conducting a visual evaluation of urban areas. The results of the estimation are presented using the urban system Ivano-Frankivsk as the example. The main stages of the evaluation of visual influences are highlighted. These stages are the city zoning according to the presence and types of dominant visual objects, the clarification of the list of those criteria which are necessary to evaluate the quality of the visual environment, the choice of the optimal solution concerning the evaluation procedure and regarding the selection of the appropriate number of points on the urban system territory, and, finally, carrying out the evaluation itself in accordance with thirty criteria.  The authors of the publication substantiate visual evaluation procedure based on the suggested method together with some elements of the method of multi-criteria analysis. Using the results of the evaluation, the authors construct the map of visual influences and carry out a complex spatial analysis of the visual fields of Ivano-Frankivsk. The article solves the problem of comprehensive evaluation of the ecological situation of urbanized systems and living conditions of the population, taking into account the evaluation of the visual environment quality.

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