scholarly journals Still moving: The double-drift illusion survives smooth pursuit

2019 ◽  
Author(s):  
Patrick Cavanagh ◽  
Peter U. Tse
Keyword(s):  
Visual Processing ◽  
Internal Motion ◽  
Orthogonal Direction ◽  
Pursuit Eye Movements ◽  
The World ◽  
Spatial Coordinates ◽  
Path Lengths ◽  
Internal Texture ◽  
Vector Combination ◽  
Moving Fixation

AbstractIf a gabor pattern drifts in one direction while its internal texture drifts in the orthogonal direction, observers see a remarkable shift in its perceived direction when it is viewed in the periphery. The reported direction of the double-drift stimulus (also known as the infinite regress and curveball illusions) is some combination of the actual external motion of the gabor envelope and the internal motion of its texture (Tse & Hsieh, 2006). Here we find that if the observers track a fixation point that moves in tandem with the gabor, the illusion is undiminished. The pursuit of the moving fixation spot keeps the gabor roughly fixed at one location on the retina, cancelling its external motion, leaving only the internal motion. The gabor is seen to move in the world at roughly its actual speed as the motion of the eye is discounted at some point to recover velocities in world coordinates (e.g. Wallach, 1959). Our finding indicates that the combination of internal and external motion that produces the double drift illusion must happen after the eye movement signals have been factored into stimulus motions. We also test the double drift effect at various path lengths, durations, and speeds, with both mid-grey and black backgrounds, all with a static fixation. These results confirm that a simple vector combination of the two speeds alone accounts for virtually all the direction shifts on the grey background. On the black background, the illusion is eliminated. These results place constraints on where perceived spatial coordinates arise in the visual processing hierarchy to locations at or beyond where compensation for pursuit eye movements arise, specifically V3A, V6, MSTd, and VIP (e.g., Nau et al, 2018).

Learning About the World by Learning About Images

2021 ◽  
pp. 096372142199033
Author(s):  
Katherine R. Storrs ◽  
Roland W. Fleming
Keyword(s):  
Neural Networks ◽  
Deep Learning ◽  
Visual Processing ◽  
Visual Experience ◽  
Natural Images ◽  
Sensory Coding ◽  
The World ◽  
Unsupervised Deep Learning ◽  
Statistical Regularities ◽  
Sensory Encoding

One of the deepest insights in neuroscience is that sensory encoding should take advantage of statistical regularities. Humans’ visual experience contains many redundancies: Scenes mostly stay the same from moment to moment, and nearby image locations usually have similar colors. A visual system that knows which regularities shape natural images can exploit them to encode scenes compactly or guess what will happen next. Although these principles have been appreciated for more than 60 years, until recently it has been possible to convert them into explicit models only for the earliest stages of visual processing. But recent advances in unsupervised deep learning have changed that. Neural networks can be taught to compress images or make predictions in space or time. In the process, they learn the statistical regularities that structure images, which in turn often reflect physical objects and processes in the outside world. The astonishing accomplishments of unsupervised deep learning reaffirm the importance of learning statistical regularities for sensory coding and provide a coherent framework for how knowledge of the outside world gets into visual cortex.

In search of the ultimate evidence: The fastest visual reaction adapts to environment, not retinal locations

2001 ◽  
Vol 24 (5) ◽  
pp. 1008-1009 ◽  
Author(s):  
Boris M. Velichkovsky ◽  
Sebastian Pannasch
Keyword(s):  
Visual Processing ◽  
Direct Realism ◽  
Distractor Effect ◽  
The World ◽  
Visual Reaction

The sensorimotor account of perception is akin to Gibsonian direct realism. Both emphasize external properties of the world, challenging views based on the analysis of internal visual processing. To compare the role of distal and retinotopic parameters, distractor effect – an optomotor reaction of midbrain origin – is considered. Even in this case, permanence in the environment, not on the retina, explains the dynamics of habituation.

scholarly journals Apparent Motion Is Computed in Perceptual Coordinates

i-Perception ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 204166952093330
Author(s):  
Jiahan Hui ◽  
Yue Wang ◽  
Peng Zhang ◽  
Peter U. Tse ◽  
Patrick Cavanagh
Keyword(s):  
Apparent Motion ◽  
Orthogonal Direction ◽  
Physical Location ◽  
Visual Periphery ◽  
Target Probe ◽  
Internal Texture

When a Gabor moves in one direction in the visual periphery while its internal texture moves in the orthogonal direction, its perceived direction can deviate from its physical direction by as much as 45° or more. Lisi et al. showed that immediate saccades go to the physical location of double-drift targets, whereas delayed saccades primarily go to their perceived locations. Here, we investigated whether the apparent motion seen from the offset of a double-drift stimulus to the onset of a later target probe originates from the perceived or physical location of the double-drift stimulus. We find that apparent motion proceeds away from the perceived position of the double-drift stimulus at all temporal delays. This suggests that apparent motion is computed in perceptual rather than retinotopic coordinates.

scholarly journals Real and Exotic Siberia in Vsevolod Ivanov’s Story “The Return of the Buddha”

2020 ◽  
Vol 15 (2) ◽  
pp. 39-52
Author(s):  
E. A. Papkova
Keyword(s):  
Scientific Work ◽  
Communist Society ◽  
The West ◽  
The World ◽  
Spatial Coordinates ◽  
Encyclopedic Dictionary ◽  
Spatio Temporal ◽  
Chinese Texts ◽  
Soviet Russia ◽  
The Buddha

The article examines two opposing images of Siberia, created in the story of Vsevolod Ivanov “The Return of the Buddha”. It is noted that the main feature of the writer’s works of the early 1920s critics both at home and abroad called it “the discovery of Siberia”, while emphasizing that “East and Asia prevail in Vsevolod Ivanov’s Siberia” (A. Voronsky). In the story “The Return of the Buddha” in the description of Siberia during the Civil War the terrible realities are emphasized: destruction, insurrections, famine, cruelty both on the part of the white guards and on the part of the Reds, against the background of which the representatives of the Soviet power are very ironically given. Exotic Siberia has different, extended spatio-temporal boundaries and includes the legend of the 300 th awakening of the Buddha, told to the hero of the story by the Mongol Dava-Dorzhchi, as well as the verses of Chinese poets given in epigraphs to its chapters. The real sources of the legend texts (“Encyclopedic Dictionary” by F. A. Brockhaus and I. A. Efron) and poems of ancient Chinese poets – the scientific work of V. M. Alekseeva “Chinese poem about a poet. Stansi Sykun Tu (837–908). Translation and research with attachment of Chinese texts” (Petrograd, 1916). The author of the article shows that, despite the formal remoteness of the spatial coordinates of this exotic world from Siberia, their inextricable connection is affirmed in the story. Exotic Siberia, as the author of the article proves, is a part of the vast, mysterious East – the world of high spirit, selfless devotion, faith and freedom acquired by man. Ivanov’s idea that the East, and not the West, is the focus of spirituality and culture is considered in the article in the historical, political and bio- graphical contexts of the early 1920s. In the policy of Soviet Russia, it was at this time that a turn to the East was taking place – the preparation of elements of the Asian orientation of the world revolution. However, for Ivanov, as the author of the article shows, the East is by no means an oasis of the future communist society. His understanding of the East and West is much closer to the concepts of philosophers, authors of the books “Exodus to the East. Premonitions and accomplishments. Approval of the Eurasians” (1921) and “Oswald Spengler” and “The Decline of Europe” (1922). The biographical realities of the life of the writer, who in 1921 came from his native Siberian East to the West – to Petrograd, could also contribute to the creation of a spiritualized and attractive image of Siberia in the story “The Return of the Buddha”.

From the Autochthonousphere to the Allochthonousphere: Escaping the Logics of Plantations and the Moving Target

2019 ◽  
pp. 237-255
Author(s):  
Chantelle Gray van Heerden
Keyword(s):  
Racial Violence ◽  
Moving Target ◽  
The World ◽  
Real Change ◽  
Spatial Coordinates

Chantelle Gray van Heerden argues that plantation logics create a particular appreciative of the spatial coordinates of histories since the carceral, a kind of facialisation of power, is always reliant on binarisation and biunivocalisation. She argues that in order to bring about real change in the world, anarchism has to become imperceptible without invisibilising whitenesss. Drawing on Deleuze’s The Logic of Sense, she invites the reader to reconsider the surface and the ground. This, she holds, can help us think about how to disrupt the spatial coordinates of the plantation and the racial violence it portends.

The Effect of Medium and Interaction

1999 ◽  
Author(s):  
Agnes Kukulska-Hulme
Keyword(s):  
Visual Processing ◽  
Natural Habitat ◽  
Spoken Language ◽  
Written Language ◽  
Spatial Proximity ◽  
Older Children ◽  
Reading And Writing ◽  
The World ◽  
The Relationship ◽  
Indirect Reference

• Why are electronic texts suspect? • Can you tear out a page on a screen? • How does chopping up sentences make them coherent? • When do actions speak louder than words? • How can we use questions to map out knowledge needs? . . . We begin this chapter by looking at what is to be gained from understanding the relationship between written and spoken language. The consequences of putting words on the screen are explored, in terms of changes in the meaning of terms, pronunciation, and the effect of spatial proximity on meanings. We then move on to consider aspects of verbal interaction, such as politeness and fluency, and conclude with an overview of users’ knowledge needs identified by analyzing their language. Written texts all have to be related somehow, directly or indirectly, to the world of sound, the natural habitat of language, to yield their meanings. The world of sound as “the natural habitat of language.” Historically, and in an individual’s development, speech comes before writing. For a small child, language is all speech. This is obviously not so for older children and adults, and for some, language is nearly all reading and writing. Still, for most people, language is strongly associated with sound, in a concrete way through hearing and producing language as well as through mental association. In a situation where computers are used, spoken and written language are both present in some way (not necessarily at the same time), not least of all because it is most unusual for someone to use an application without ever speaking about its use! In general, indirect reference from written language to sound through a reader’s prior experience of spoken language or through a special notation is acceptable in many different circumstances, such as in books and newspapers. The question is, What, if anything, do we lose when real sound is missing? Physical demands on the reader (user) are now focused on visual processing.

scholarly journals The influence of object-colour knowledge on emerging object representations in the brain

2019 ◽  
Author(s):  
Lina Teichmann ◽  
Genevieve L. Quek ◽  
Amanda K. Robinson ◽  
Tijl Grootswagers ◽  
Thomas A. Carlson ◽  
...  
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Conceptual Knowledge ◽  
Brain Activity ◽  
Central Feature ◽  
Object Representations ◽  
Complex Objects ◽  
Object Knowledge ◽  
The World ◽  
Object Features

AbstractThe ability to rapidly and accurately recognise complex objects is a crucial function of the human visual system. To recognise an object, we need to bind incoming visual features such as colour and form together into cohesive neural representations and integrate these with our pre-existing knowledge about the world. For some objects, typical colour is a central feature for recognition; for example, a banana is typically yellow. Here, we applied multivariate pattern analysis on time-resolved neuroimaging (magnetoencephalography) data to examine how object-colour knowledge affects emerging object representations over time. Our results from 20 participants (11 female) show that the typicality of object-colour combinations influences object representations, although not at the initial stages of object and colour processing. We find evidence that colour decoding peaks later for atypical object-colour combinations in comparison to typical object-colour combinations, illustrating the interplay between processing incoming object features and stored object-knowledge. Taken together, these results provide new insights into the integration of incoming visual information with existing conceptual object knowledge.Significance StatementTo recognise objects, we have to be able to bind object features such as colour and shape into one coherent representation and compare it to stored object knowledge. The magnetoencephalography data presented here provide novel insights about the integration of incoming visual information with our knowledge about the world. Using colour as a model to understand the interaction between seeing and knowing, we show that there is a unique pattern of brain activity for congruently coloured objects (e.g., a yellow banana) relative to incongruently coloured objects (e.g., a red banana). This effect of object-colour knowledge only occurs after single object features are processed, demonstrating that conceptual knowledge is accessed relatively late in the visual processing hierarchy.

Football Globalization, Fans of European Leagues and the Spatiality of Viewing Centers in a Nigerian City

2018 ◽  
Author(s):  
Victor Udemeue Onyebueke
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Social Life ◽  
Contemporary Literature ◽  
Social Scientists ◽  
The World ◽  
Transportation Corridors ◽  
Spatial Coordinates ◽  
Current Article

Football is arguably the world’s most globalized sport, and is implicated in the continuing efforts of social scientists to understand current globalization processes. In cities across the world, transnational broadcast of live matches of European leagues, involving elite clubs like Manchester United, Chelsea, Barcelona and other elite teams/players, is engendering ritualized television spectating, which in turn is leading to the proliferation of ‘football bars’ or football viewing centres (FVCs). Globalization-induced telemediation of urban social life and subculture formation is specialized in these ‘virtual stadiums’, entertainment/socializing centres, and ‘windows’ to the outside world, where fan-ship behaviours are both formed and reinforced. The current article attempts to fill the yawning spatiality gap in contemporary literature on football globalization and media transnationalism by exploring FVCs as ‘spatial coordinates’ of globalization, and unpacking its geospatial, socio-demographic and land use change attributes in a typical Nigerian city. The explorative results revealed significant clustering around the central areas with orientation in the direction of the major transportation corridors.

scholarly journals A perceptual bias for man-made objects in humans

2019 ◽  
Vol 286 (1914) ◽  
pp. 20191492 ◽  
Author(s):  
Ahamed Miflah Hussain Ismail ◽  
Joshua A. Solomon ◽  
Miles Hansard ◽  
Isabelle Mareschal
Keyword(s):  
Visual Processing ◽  
Human Perception ◽  
Perceptual Bias ◽  
Object Categories ◽  
Naturally Occurring ◽  
Early Visual Processing ◽  
Two Component ◽  
The World ◽  
First Time ◽  
Extended Exposure

Ambiguous images are widely recognized as a valuable tool for probing human perception. Perceptual biases that arise when people make judgements about ambiguous images reveal their expectations about the environment. While perceptual biases in early visual processing have been well established, their existence in higher-level vision has been explored only for faces, which may be processed differently from other objects. Here we developed a new, highly versatile method of creating ambiguous hybrid images comprising two component objects belonging to distinct categories. We used these hybrids to measure perceptual biases in object classification and found that images of man-made (manufactured) objects dominated those of naturally occurring (non-man-made) ones in hybrids. This dominance generalized to a broad range of object categories, persisted when the horizontal and vertical elements that dominate man-made objects were removed and increased with the real-world size of the manufactured object. Our findings show for the first time that people have perceptual biases to see man-made objects and suggest that extended exposure to manufactured environments in our urban-living participants has changed the way that they see the world.

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