scholarly journals Prevalence of visual snow and relation to attentional absorption

2021 ◽  
Author(s):  
Rui Costa ◽  
Pedro Campos ◽  
Madalena Wiborg ◽  
Catarina Rebôlo ◽  
Marc Wittmann ◽  
...  
Keyword(s):  
Visual Field ◽  
Emotional Reactions ◽  
Clinical Samples ◽  
Online Surveys ◽  
Portuguese Population ◽  
Behavioral Correlates ◽  
Entire Visual Field ◽  
Neurophysiological Mechanisms ◽  
Animated Graphic ◽  
Tellegen Absorption Scale

Visual snow is a condition of unclear prevalence characterized by tiny flickering dots throughout the entire visual field. It appears to result from visual cortex hyperactivity and possibly correlates with propensity to be engrossed in sensory and imaginary experiences (absorption). The prevalence and correlates of visual snow, and emotional reactions to it, were explored in the general Portuguese population with three studies with online surveys. In Study 1, 564 participants were shown an animated graphic simulation of visual snow and asked to rate how frequently they see it on a scale anchored by 0% and 100% of the time. They also reported their degree of distress and fascination resulting from visual snow. Absorption was measured with the Modified Tellegen Absorption Scale. 44% of respondents reported they see visual snow at least 10% of the time, and 20% reported seeing it between 80% and 100% of the time. Similar to findings in clinical samples, the frequency of visual snow correlated with tinnitus frequency, migraine, and entoptic phenomena, but not with ophthalmologic problems. It was confirmed that visual snow is related to absorption. Although distress caused by visual snow was generally absent or minimal, a substantial minority (28%) reported moderate to high levels of distress. High fascination with visual snow was reported by 9%. In Studies 2 and 3, visual snow was measured by means of verbal descriptions without graphic simulation (“visual field full of tiny dots of light” and “world seen with many dots of light”, respectively). The results were similar to those in Study 1, but seeing visual snow 80%-100% of the time was less frequent (6.5% in Study 2 and 3.6% in Study 3). Visual snow has been insufficiently investigated. More research is needed to uncover underlying neurophysiological mechanisms and psychological and behavioral correlates.

Pediatric Visual Snow Syndrome (VSS): A Case Series

2019 ◽  
pp. 249-254
Author(s):  
Kenneth J. Ciuffreda ◽  
MH Esther Han ◽  
Barry Tannen
Keyword(s):  
Visual Field ◽  
Case Series ◽  
Therapeutic Interventions ◽  
Visual Condition ◽  
Visual Phenomena ◽  
Entire Visual Field ◽  
The Individual ◽  
Vision Therapy ◽  
Abnormal Visual

Visual snow syndrome (VSS) is a relatively rare, unusual, and disturbing abnormal visual condition. The individual perceives “visual snow” (VS) throughout the entire visual field, as well as other abnormal visual phenomena (e.g., photopsia). Only relatively recently has treatment been proposed (e.g., chromatic filters) in adults with VSS, but rarely in the pediatric VSS population (i.e., medications). In this paper, we present three well-documented cases of VSS in children, including their successful neuro-optometric therapeutic interventions (i.e., chromatic filters and saccadic-based vision therapy)

Occipitoparietal alpha-band responses to the graded allocation of top-down spatial attention

2014 ◽  
Vol 112 (6) ◽  
pp. 1307-1316 ◽  
Author(s):  
Isabel Dombrowe ◽  
Claus C. Hilgetag
Keyword(s):  
Visual Field ◽  
Spatial Attention ◽  
Brain Regions ◽  
Alpha Band ◽  
Top Down ◽  
Attentional Resources ◽  
Parietal Lobes ◽  
Visual Spatial ◽  
Entire Visual Field ◽  
Band Activity

The voluntary, top-down allocation of visual spatial attention has been linked to changes in the alpha-band of the electroencephalogram (EEG) signal measured over occipital and parietal lobes. In the present study, we investigated how occipitoparietal alpha-band activity changes when people allocate their attentional resources in a graded fashion across the visual field. We asked participants to either completely shift their attention into one hemifield, to balance their attention equally across the entire visual field, or to attribute more attention to one-half of the visual field than to the other. As expected, we found that alpha-band amplitudes decreased stronger contralaterally than ipsilaterally to the attended side when attention was shifted completely. Alpha-band amplitudes decreased bilaterally when attention was balanced equally across the visual field. However, when participants allocated more attentional resources to one-half of the visual field, this was not reflected in the alpha-band amplitudes, which just decreased bilaterally. We found that the performance of the participants was more strongly reflected in the coherence between frontal and occipitoparietal brain regions. We conclude that low alpha-band amplitudes seem to be necessary for stimulus detection. Furthermore, complete shifts of attention are directly reflected in the lateralization of alpha-band amplitudes. In the present study, a gradual allocation of visual attention across the visual field was only indirectly reflected in the alpha-band activity over occipital and parietal cortexes.

scholarly journals Brightness Perception Throughout the Entire Visual Field

2015 ◽  
Vol 99 (5) ◽  
pp. 258-262 ◽  
Author(s):  
Tasuku Watanuki ◽  
Hiroshi Takahashi ◽  
Takashi Irikura
Keyword(s):  
Visual Field ◽  
Brightness Perception ◽  
Entire Visual Field

scholarly journals Visuospatial Attention and the Split Brain

Physiology ◽  
1997 ◽  
Vol 12 (5) ◽  
pp. 226-231
Author(s):  
G Berlucchi ◽  
GR Mangun ◽  
MS Gazzaniga
Keyword(s):  
Visual Field ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Visuospatial Attention ◽  
Attentional Biases ◽  
Split Brain ◽  
Right Hemisphere Damage ◽  
Entire Visual Field ◽  
The Right

In callosotomy patients, the right hemisphere attends to the entire visual field, whereas the left hemisphere attends to the right field only. The occurence of rightward attentional biases, simulating a hemineglect from right hemisphere damage, suggests that in these patients visuospatial attention tends to be controlled by the left hemisphere.

Recent Advances in Understanding Peripheral Vision

1986 ◽  
Vol 30 (6) ◽  
pp. 601-603 ◽  
Author(s):  
Mark W. Cannon
Keyword(s):  
Visual Field ◽  
Spatial Pattern ◽  
Peripheral Vision ◽  
Pattern Perception ◽  
Recent Advances ◽  
Entire Visual Field

Recent experiments have revealed a considerable uniformity in the mechanisms mediating spatial pattern perception over the entire visual field.

scholarly journals Spherical arena reveals optokinetic response tuning to stimulus location, size, and frequency across entire visual field of larval zebrafish

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Florian Alexander Dehmelt ◽  
Rebecca Meier ◽  
Julian Hinz ◽  
Takeshi Yoshimatsu ◽  
Clara A Simacek ◽  
...  
Keyword(s):  
Visual Field ◽  
Frequency Tuning ◽  
Sample Stimulus ◽  
Visual Fields ◽  
Visual Space ◽  
Motion Vision ◽  
Optokinetic Response ◽  
Larval Zebrafish ◽  
Retinal Processing ◽  
Entire Visual Field

Many animals have large visual fields, and sensory circuits may sample those regions of visual space most relevant to behaviours such as gaze stabilisation and hunting. Despite this, relatively small displays are often used in vision neuroscience. To sample stimulus locations across most of the visual field, we built a spherical stimulus arena with 14,848 independently controllable LEDs. We measured the optokinetic response gain of immobilised zebrafish larvae to stimuli of different steradian size and visual field locations. We find that the two eyes are less yoked than previously thought and that spatial frequency tuning is similar across visual field positions. However, zebrafish react most strongly to lateral, nearly equatorial stimuli, consistent with previously reported spatial densities of red, green and blue photoreceptors. Upside-down experiments suggest further extra-retinal processing. Our results demonstrate that motion vision circuits in zebrafish are anisotropic, and preferentially monitor areas with putative behavioural relevance.

Faith Ringgold’s Story Quilts

2018 ◽  
pp. 196-213
Author(s):  
Hertha D. Sweet Wong
Keyword(s):  
African American ◽  
Visual Field ◽  
Square Functions ◽  
Art Gallery ◽  
Race And Gender ◽  
American Artist ◽  
History Of ◽  
Entire Visual Field ◽  
And Gender

African American artist Faith Ringgold’s oversized story quilts are painted and stitched image-text narratives on fabric intended to be hung on art gallery walls. In all her work she thematizes race and gender, part of her project to revise historical misrepresentations and generate more accurate depictions. This chapter discusses Ringgold’s various interventions in a long history of textual and visual domination, noting also Ringgold’s innovations: how quilt squares function simultaneously as individual images or texts and as part of the entire visual field. Each quilt square functions as a page, while a series of quilt squares can function also as a frame. The sets of relations between page and frame and between image and text are multiple and variable.

Wounding realities and ‘painful excitements’: real sympathy, the imitation of suffering and the visual arts after Burke’s sublime

2017 ◽  
Author(s):  
Aris Sarafianos
Keyword(s):  
Visual Field ◽  
Visual Arts ◽  
Aesthetic Experience ◽  
Modern Art ◽  
Vital Role ◽  
Art Practices ◽  
Entire Visual Field ◽  
The Way

This chapter shows the vital role of injury and suffering in redefining art practices and aesthetic experience from the 1750s onwards. It investigates the role of Burke’s sublime in the introduction of a new lust for pain, which was combined with an equally painful call for the amplification of visual experiences – real and imitated. Sarafianos stresses Burke’s uncivil redefinition of sympathy as a painful delight in the suffering of others, and argues that, despite established anti-visual interpretations of Burke’s sub lime, such extreme forms of suffering are at the root of the way in which his Philosophical Enquiry (1757) built powerful continuities between ‘real sympathy’ and the reality of imitations in painting or theatre. Moreover, this chapter demonstrates that the same principles led to the reorganisation of the entire visual field: bodies in pain, painstaking styles of representation and hurtful habits of seeing were tied up in ways that determined the bursting forth of a specially modern kind of realism. Sarafianos uses Sir Charles Bell’s gruesome surgical sketches from Waterloo (1815) in order to show that the same tangle of hurtful experiences, tailored on Burke’s precise guidelines, encapsulated drives and aspirations for a ‘sublime real’ with a long career in modern art and criticism.

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