scholarly journals Character Decomposition and Transposition of Chinese Compound Words in the Right and Left Visual Fields

i-Perception ◽  
2016 ◽  
Vol 7 (6) ◽  
pp. 204166951667536 ◽  
Author(s):  
Hong-Wen Cao ◽  
Kai-Fu Yang ◽  
Hong-Mei Yan
Keyword(s):  
Visual Fields ◽  
Compound Words ◽  
The Right

On the Relation between Visual Spatial Attention and Visual Field Asymmetries

1992 ◽  
Vol 44 (3) ◽  
pp. 529-555 ◽  
Author(s):  
T. A Mondor ◽  
M.P. Bryden
Keyword(s):  
Visual Field ◽  
Visual Attention ◽  
Visual Fields ◽  
Stimulus Onset ◽  
Right Visual Field ◽  
Structural Factors ◽  
Letter Identification ◽  
Functional Capabilities ◽  
Visual Spatial ◽  
The Right

In the typical visual laterality experiment, words and letters are more rapidly and accurately identified in the right visual field than in the left. However, while such studies usually control fixation, the deployment of visual attention is rarely restricted. The present studies investigated the influence of visual attention on the visual field asymmetries normally observed in single-letter identification and lexical decision tasks. Attention was controlled using a peripheral cue that provided advance knowledge of the location of the forthcoming stimulus. The time period between the onset of the cue and the onset of the stimulus (Stimulus Onset Asynchrony—SOA) was varied, such that the time available for attention to focus upon the location was controlled. At short SO As a right visual field advantage for identifying single letters and for making lexical decisions was apparent. However, at longer SOAs letters and words presented in the two visual fields were identified equally well. It is concluded that visual field advantages arise from an interaction of attentional and structural factors and that the attentional component in visual field asymmetries must be controlled in order to approximate more closely a true assessment of the relative functional capabilities of the right and left cerebral hemispheres.

scholarly journals When brain damage “improves” perception: neglect patients can localize motion-shifted probes better than controls

2015 ◽  
Vol 114 (6) ◽  
pp. 3351-3358 ◽  
Author(s):  
Stefania de Vito ◽  
Marine Lunven ◽  
Clémence Bourlon ◽  
Christophe Duret ◽  
Patrick Cavanagh ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Visual Fields ◽  
Critical Factor ◽  
Significant Shift ◽  
Stimulus Motion ◽  
Attentional Processes ◽  
Position Shift ◽  
The Right ◽  
High Level ◽  
Better Than

When we look at bars flashed against a moving background, we see them displaced in the direction of the upcoming motion (flash-grab illusion). It is still debated whether these motion-induced position shifts are low-level, reflexive consequences of stimulus motion or high-level compensation engaged only when the stimulus is tracked with attention. To investigate whether attention is a causal factor for this striking illusory position shift, we evaluated the flash-grab illusion in six patients with damaged attentional networks in the right hemisphere and signs of left visual neglect and six age-matched controls. With stimuli in the top, right, and bottom visual fields, neglect patients experienced the same amount of illusion as controls. However, patients showed no significant shift when the test was presented in their left hemifield, despite having equally precise judgments. Thus, paradoxically, neglect patients perceived the position of the flash more veridically in their neglected hemifield. These results suggest that impaired attentional processes can reduce the interaction between a moving background and a superimposed stationary flash, and indicate that attention is a critical factor in generating the illusory motion-induced shifts of location.

scholarly journals P32 Relapsing polychondritis with anterior scleritis in young female

2021 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
Umair Arain ◽  
Abimbola Phillips ◽  
Ben Burton ◽  
Damodar Makkuni
Keyword(s):  
Rheumatoid Arthritis ◽  
Case Report ◽  
Visual Fields ◽  
Delayed Diagnosis ◽  
Relapsing Polychondritis ◽  
Young Female ◽  
Blurred Vision ◽  
Ocular Findings ◽  
Anterior Scleritis ◽  
The Right

Abstract Case report - Introduction Relapsing polychondritis (RP) was first recognized as a clinical entity in 1923 by Jaksch-Wartenhorst (1923) and reported by him under the title "polychondropathia". The term "relapsing polychondritis" was first used by Pearson, Kline, and Newcomer (1960). Because the ocular findings can be the initial findings of RP, ophthalmologists should know the major ocular findings of this disease. Isaak et al reported that the most common ocular finding is episcleritis (39%) and the second is scleritis (14%). Other signs are iritis (9%), retinopathy (9%), muscle paresis (5%), and optic neuritis (5%). Case report - Case description A 45-year-old female with known rheumatoid arthritis referred by rheumatology in eye clinic due to blurred vision and dry eye. The patient was on hydroxychloroquine and sulfasalazine. No retinal toxicity was found on examination, OCT and Visual Fields. The vision was 6/6 both eyes. Follow-up was in 12 months. She presented 6 months later in casualty with severe pain in her right eye. Examination showed diffuse anterior scleritis with secondary conjunctival inflammation. Anterior chamber cells present. Posterior segment showed no inflammation. Left eye was unremarkable. She was started on Froben 100mg tds with omeprazole. She was seen after a week and condition was improving. She was asked to taper off the meds. Inflammation resolved with 6/5 vision in both eyes and the next appointment was made in a year to monitor for hydroxychloroquine toxicity. In November 2020 she was seen by ENT with inflammation of the right ear cartilage. The pictures showed that the pinna was spared and cartilage was only involved. There was nasal crusting and stuffy nose but without any respiratory symptoms. She was prescribed 50mgs of prednisolone and this helped with her inflammation. She was seen by rheumatology later on and hydroxychloroquine and sulfasalazine was stopped, and she was started on methotrexate 10mgs weekly and folic acid 5mg weekly. Pulmonary function test and echocardiogram was ordered. The case was discussed in MDT rheumatology and it was decided that if joint symptoms got worse than biologics could be started. Methotrexate increased to 15mg subcut. Echocardiogram was normal with satisfactory blood tests. Her next appointment is in October 2021. Case report - Discussion Initially the patient was diagnosed with rheumatoid arthritis with ocular inflammation (anterior scleritis) and was given the standard treatment of steroids to which the patient responded as well. Later when she developed the ear inflammation which involved only the cartilage the diagnosis was revised by rheumatology and changed to RP. As this is a rare life-threatening disease management was switched to immunosuppressive therapy to which she is currently responding well. Case report - Key learning points It is important to consider the possibility that a rheumatology patient may have more than one diagnosis or be open to the idea of revising the diagnosis as the clinical picture evolves over the time. Given the nature of the disease all the systemic features should be examined thoroughly as any one missed area can lead to delayed diagnosis.

Interocular torsional disparity and visual cortical development in the cat

1990 ◽  
Vol 64 (4) ◽  
pp. 1352-1360 ◽  
Author(s):  
M. R. Isley ◽  
D. C. Rogers-Ramachandran ◽  
P. G. Shinkman
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Ocular Dominance ◽  
Visual Fields ◽  
Receptive Fields ◽  
Right Visual Field ◽  
Orientation Columns ◽  
Areas 17 And 18 ◽  
The Right ◽  
Visual Cortical

1. The present experiments were designed to assess the effects of relatively large optically induced interocular torsional disparities on the developing kitten visual cortex. Kittens were reared with restricted visual experience. Three groups viewed a normal visual environment through goggles fitted with small prisms that introduced torsional disparities between the left and right eyes' visual fields, equal but opposite in the two eyes. Kittens in the +32 degrees goggle rearing condition experienced a 16 degrees counterclockwise rotation of the left visual field and a 16 degrees clockwise rotation of the right visual field; in the -32 degrees goggle condition the rotations were clockwise in the left eye and counterclockwise in the right. In the control (0 degree) goggle condition, the prisms did not rotate the visual fields. Three additional groups viewed high-contrast square-wave gratings through Polaroid filters arranged to provide a constant 32 degrees of interocular orientation disparity. 2. Recordings were made from neurons in visual cortex around the border of areas 17 and 18 in all kittens. Development of cortical ocular dominance columns was severely disrupted in all the experimental (rotated) rearing conditions. Most cells were classified in the extreme ocular dominance categories 1, 2, 6, and 7. Development of the system of orientation columns was also affected: among the relatively few cells with oriented receptive fields in both eyes, the distributions of interocular disparities in preferred stimulus orientation were centered near 0 degree but showed significantly larger variances than in the control condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Rapidly progressive vision loss due to fulminant idiopathic intracranial hypertension: a diagnostic and management dilemma

2020 ◽  
Vol 13 (11) ◽  
pp. e236188
Author(s):  
Jagadeesh Sutraye ◽  
Mohan Kannam ◽  
Rajat Kapoor ◽  
Virender Sachdeva
Keyword(s):  
Intracranial Hypertension ◽  
Idiopathic Intracranial Hypertension ◽  
Vision Loss ◽  
Obese Woman ◽  
Visual Fields ◽  
Csf Analysis ◽  
Contrast Enhanced ◽  
Grade Ii ◽  
The Right ◽  
The Brain

A 44-year-old obese woman presented with decrease in vision in the right eye (RE) for 3 days. She reported a simultaneous onset of holocranial headache that worsened on bending forward. She denied eye pain, pain on eye movements, and other ocular or neurological complaints. On examination, her distance best-corrected visual acuity was counting fingers at 1 m in the RE and 20/20 in the left eye (LE). Colour vision was subnormal in both eyes (BE). There was grade II relative afferent pupillary defect in the RE. Fundus examination showed disc oedema in BE . Visual fields in the LE showed central scotoma extending nasally. A provisional diagnosis of papillitis was considered. However, contrast-enhanced MRI of the brain and orbits showed evidence of elevated intracranial pressure. Cerebrospinal fluid (CSF) opening pressure was 42 cm H2O while rest of the CSF analysis was normal. Diagnosis was revised to fulminant idiopathic intracranial hypertension. Management with medical therapy and urgent thecoperiteoneal shunt improved visual function in BE.

scholarly journals Bilateral Glaucomatous Optic Neuropathy Caused by Eye Rubbing

2015 ◽  
Vol 6 (3) ◽  
pp. 279-283 ◽  
Author(s):  
Alfonso Savastano ◽  
Maria Cristina Savastano ◽  
Laura Carlomusto ◽  
Silvio Savastano
Keyword(s):  
Intraocular Pressure ◽  
Visual Field ◽  
Optic Disc ◽  
Optic Neuropathy ◽  
Correct Diagnosis ◽  
Visual Fields ◽  
Pattern Electroretinogram ◽  
Glaucomatous Optic Neuropathy ◽  
Fiber Layer ◽  
The Right

In this report, we describe a particular condition of a 52-year-old man who showed advanced bilateral glaucomatous-like optic disc damage, even though the intraocular pressure resulted normal during all examinations performed. Visual field test, steady-state pattern electroretinogram, retinal nerve fiber layer and retinal tomographic evaluations were performed to evaluate the optic disc damage. Over a 4-year observational period, his visual acuity decreased to 12/20 in the right eye and counting fingers in the left eye. Visual fields were severely compromised, and intraocular pressure values were not superior to 14 mm Hg during routine examinations. An accurate anamnesis and the suspicion of this disease represent a crucial aspect to establish the correct diagnosis. In fact, our patient strongly rubbed his eyes for more than 10 h per day. Recurrent and continuous eye rubbing can induce progressive optic neuropathy, causing severe visual field damage similar to the pathology of advanced glaucoma.

Vocal Reaction Times to Tachistoscopically Presented High- and Low-Frequency Verbs: Some Evidence for Selective Minor Hemisphere Linguistic Analysis

1988 ◽  
Vol 66 (3) ◽  
pp. 803-810 ◽  
Author(s):  
Michael P. Rastatter ◽  
Catherine Loren
Keyword(s):  
Visual Field ◽  
High Frequency ◽  
Right Hemisphere ◽  
Visual Fields ◽  
Reaction Times ◽  
Low Frequency ◽  
Normal Subjects ◽  
Right Visual Field ◽  
Intact Brain ◽  
The Right

The current study investigated the capacity of the right hemisphere to process verbs using a paradigm proven reliable for predicting differential, minor hemisphere lexical analysis in the normal, intact brain. Vocal reaction times of normal subjects were measured to unilaterally presented verbs of high and of low frequency. A significant interaction was noted between the stimulus items and visual fields. Post hoc tests showed that vocal reaction times to verbs of high frequency were significantly faster following right visual-field presentations (right hemisphere). No significant differences in vocal reaction time occurred between the two visual fields for the verbs of low frequency. Also, significant differences were observed between the two types of verbs following left visual-field presentation but not the right. These results were interpreted to suggest that right-hemispheric analysis was restricted to the verbs of high frequency in the presence of a dominant left hemisphere.

scholarly journals Right Hemisphere Activation of Joke-related Information: An Event-related Brain Potential Study

2005 ◽  
Vol 17 (3) ◽  
pp. 494-506 ◽  
Author(s):  
Seana Coulson ◽  
Ying Choon Wu
Keyword(s):  
Priming Effect ◽  
Right Hemisphere ◽  
Visual Fields ◽  
Relevant Information ◽  
Task Demands ◽  
Hemispheric Differences ◽  
Brain Potentials ◽  
Related Information ◽  
The Right ◽  
High Level

Two studies tested the hypothesis that the right hemisphere engages in relatively coarse semantic coding that aids high-level language tasks such as joke comprehension. Scalp-recorded event-related brain potentials (ERPs) were collected as healthy adults read probe words (CRAZY) preceded either by jokes or nonfunny controls (“Everyone had so much fun jumping into the swimming pool, we decided to put in a littlewater/platform”). Probes were related to the meaning of the jokes, but not the controls. In Experiment 1a, with central presentation, probes following jokes (related) elicited less negative ERPs 300–700 msec postonset (N400) than did probes following nonfunny controls (unrelated). This finding suggests related probes were primed by the jokes. In addition, unrelated probes elicited a larger anterior positivity 700– 900 msec than did related, as irrelevant stimuli impacted control processes invoked by task demands. In Experiment 1b, probes (CRAZY) were preceded only by sentence-final words from jokes (water) or controls (platform). No ERP effects were observed in Experiment 1b, suggesting the N400 priming effect and the anterior positivity observed in Experiment 1a reflect semantic activations at the discourse level. To assess hemispheric differences in semantic activations, in Experiment 2, ERPs were recorded as participants read probe words presented in their left and right visual fields (LVF and RVF, respectively). Probes elicited a smaller N400 component when preceded by jokes than controls. This N400 priming effect was larger with presentation to the LVF, suggesting joke-relevant information was more active in the right hemisphere. The anterior positivity was observed with RVF but not LVF presentation, suggesting an important role for the left hemisphere in controlled retrieval in language comprehension.

Backward Contralateral Masking by Light and by Random Pattern

1983 ◽  
Vol 57 (1) ◽  
pp. 139-142
Author(s):  
Bart Jarvis ◽  
Julia Vormbrock ◽  
Dennis P. Saccuzzo
Keyword(s):  
Visual Field ◽  
Target Stimulus ◽  
Visual Fields ◽  
Random Pattern ◽  
Area 17 ◽  
Backward Masking ◽  
Pattern Mask ◽  
Cortex Area ◽  
The Right ◽  
Contralateral Masking

Letter-stimuli as targets were presented to the right or left visual fields and followed either by a flash of light or by a flash of light plus a patterned mask. The patterned mask always appeared in the opposite visual field of the letter targets. Analysis showed that masking occurred for both types of masks but that subjects produced more errors at each of five intervals between onset of the target and onset of the mask for the flash of light plus a patterned mask in the opposite visual field than for the flash of light alone. A pattern mask, when presented to the opposite visual field of a target stimulus, interferes with target processing at short target-mask intervals. These findings suggest that central backward masking may involve target-mask interactions beyond the visual cortex (Area 17).

Visual Field Sensitivity on a Two-Choice Discrimination Task

1981 ◽  
Vol 53 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Paul Salmon ◽  
Albert Rodwan
Keyword(s):  
Visual Field ◽  
Signal Detection ◽  
Left Visual Field ◽  
Discrimination Task ◽  
Visual Fields ◽  
Detection Analysis ◽  
Field Sensitivity ◽  
Signal Detection Analysis ◽  
The Right ◽  
Stimulation Of

A signal-detection analysis was used to evaluate visual-field sensitivity on a two-choice (same/different) discrimination task. Pairs of unfamiliar geometrical forms were presented tachistoscopically to the right or left visual fields of 12 subjects. Of 12 subjects 11 obtained left visual-field values which exceeded those of the right. The data suggested that the superiority of stimulation of the left visual field resulted from greater sensitivity to “same” figure pairs.

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