scholarly journals Sleep does not aid the generalisation of binocular disparity‐based learning to the other visual hemifield

2021 ◽  
Author(s):  
Jens G. Klinzing ◽  
Hendrikje Nienborg ◽  
Karsten Rauss
Keyword(s):  
Binocular Disparity ◽  
The Other ◽  
Visual Hemifield

Breakdown of Apparent Motion under Stereoscopic Viewing

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 55-55
Author(s):  
S Yukumatsu ◽  
K Bingushi
Keyword(s):  
Apparent Motion ◽  
Binocular Disparity ◽  
Three Dimensional ◽  
The Other ◽  
Bilateral Condition ◽  
Everyday Experiences ◽  
Cumulative Time

To study the effect of binocular disparity on apparent motion, we measured the cumulative time of its breakdown during a 30 s fixation viewing period. Two light spots, both on the left side of the fixation point, were alternately presented one by one on a CRT display (unilateral condition). These spots were binocularly disparate and viewed through a stereoscope. While one spot near the fixation point was presented on a zero disparity plane, the other spot (more peripheral) was either on a zero, uncrossed, or crossed disparity plane, so that three-dimensional motion could be seen depending on disparity values. We found that the duration of the breakdown of apparent motion was longer when uncrossed and zero-disparity spots were paired to produce apparent motion, and it was shorter when crossed and zero-disparity spots were paired. However, such disparity-specific tendencies were not obtained when the two spots were presented on both sides of the fixation point (bilateral condition). The disparity-specific tendencies in the unilateral condition can be explained by assuming that three-dimensional apparent motion that is consistent with the motion perspective may be stable because we experience it more frequently. Thus, we assume that perception of motion, both apparent and real, may develop through everyday experiences of moving to and fro in the environment rather than seeing objects move.

Audio–visual recalibration is spatially specific, in external coordinates

2012 ◽  
Vol 25 (0) ◽  
pp. 132
Author(s):  
David Burr ◽  
Roberto Arrighi ◽  
Marco Cicchini ◽  
David Aagten-Murphy
Keyword(s):  
Eye Movement ◽  
Visual Stimulus ◽  
The Other ◽  
Auditory Stimuli ◽  
Adaptation Period ◽  
Visual Hemifield ◽  
Zero Offset ◽  
Spatial Specificity ◽  
Ventriloquist Effect ◽  
Spatial Maps

When visual and auditory stimuli are displayed with a spatial offset, the sound is heard at or near the visual stimulus (ventriloquist effect). After an adaptation period of repeated exposure to spatially offset audio–visual stimuli, sounds presented alone are perceived spatially displaced, in the direction of the adapting offset (ventriloquist aftereffect: Recanzione, 1998), pointing to recalibration of audio–visual alignment. Here we show that the recalibration is spatially selective. Adapting, one visual hemifield to (say) a leftward offset, and the other to a rightward (or zero) offset produces two separate spatially localized aftereffects, in opposite directions. If a large (30°) eye-movement is interposed between adaptation and test, the spatial specificity remains in head-centered coordinates. The results provide further evidence for the existence of spatiotopic (or at least craniotopic) spatial maps, which are subject to continual recalibration.

Dynamic Circuitry for Updating Spatial Representations. II. Physiological Evidence for Interhemispheric Transfer in Area LIP of the Split-Brain Macaque

2005 ◽  
Vol 94 (5) ◽  
pp. 3249-3258 ◽  
Author(s):  
Laura M. Heiser ◽  
Rebecca A. Berman ◽  
Richard C. Saunders ◽  
Carol L. Colby
Keyword(s):  
Eye Movements ◽  
Visual Representations ◽  
The Other ◽  
Spatial Representations ◽  
Lateral Intraparietal Area ◽  
Split Brain ◽  
Perceptual Stability ◽  
Visual Hemifield ◽  
Principal Finding ◽  
The Brain

With each eye movement, a new image impinges on the retina, yet we do not notice any shift in visual perception. This perceptual stability indicates that the brain must be able to update visual representations to take our eye movements into account. Neurons in the lateral intraparietal area (LIP) update visual representations when the eyes move. The circuitry that supports these updated representations remains unknown, however. In this experiment, we asked whether the forebrain commissures are necessary for updating in area LIP when stimulus representations must be updated from one visual hemifield to the other. We addressed this question by recording from LIP neurons in split-brain monkeys during two conditions: stimulus traces were updated either across or within hemifields. Our expectation was that across-hemifield updating activity in LIP would be reduced or abolished after transection of the forebrain commissures. Our principal finding is that LIP neurons can update stimulus traces from one hemifield to the other even in the absence of the forebrain commissures. This finding provides the first evidence that representations in parietal cortex can be updated without the use of direct cortico-cortical links. The second main finding is that updating activity in LIP is modified in the split-brain monkey: across-hemifield signals are reduced in magnitude and delayed in onset compared with within-hemifield signals, which indicates that the pathways for across-hemifield updating are less effective in the absence of the forebrain commissures. Together these findings reveal a dynamic circuit that contributes to updating spatial representations.

Splitting Motivation

2010 ◽  
Vol 21 (7) ◽  
pp. 977-983 ◽  
Author(s):  
Liane Schmidt ◽  
Stefano Palminteri ◽  
Gilles Lafargue ◽  
Mathias Pessiglione
Keyword(s):  
Human Brain ◽  
The Body ◽  
The Other ◽  
Brain Hemisphere ◽  
Visual Hemifield ◽  
Conscious Control

Motivation is generally understood to denote the strength of a person’s desire to attain a goal. Here we challenge this view of motivation as a person-level concept, in a study that targeted subliminal incentives to only one half of the human brain. Participants in the study squeezed a handgrip to win the greatest fraction possible of each subliminal incentive, which materialized as a coin image flashed in one visual hemifield. Motivation effects (i.e., more force exerted when the incentive was higher) were observed only for the hand controlled by the stimulated brain hemisphere. These results show that in the absence of conscious control, one brain hemisphere, and hence one side of the body, can be motivated independently of the other.

scholarly journals Asymmetries During Multiple Face Encoding: Increased Dwell Time and Number of Fixations in the Upper Visual Hemifield

i-Perception ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 204166951982797 ◽  
Author(s):  
Fatima M. Felisberti ◽  
Liam Currie
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Dwell Time ◽  
The Other ◽  
Environmental Cues ◽  
Reading Habits ◽  
Visual Hemifield ◽  
Bottom Left

Visual field asymmetries in the encoding of groups of faces have rarely been investigated. Here, eye movements (percentage of dwell time [pDT] and number of fixations [nFix]) were recorded during the encoding of three groups of four faces tagged with cheating, cooperative, or neutral behaviours. Faces in each group were placed in the top left, top right, bottom left, or bottom right quadrants. Face recall was equally high in the three behavioural groups. Conversely, pDT and nFix were higher for faces in the upper hemifields. Most of the first saccades were made to the top left visual quadrant, which also commanded a higher pDT and nFix than the other quadrants. The findings are relevant to the understanding of visual field asymmetries in the processing of multiple faces, a common social scenario, and may be linked to reading habits in conjunction (or not) with cultural and environmental cues.

Perceived Angular and Linear Size: The Role of Binocular Disparity and Visual Surround

Perception ◽  
1997 ◽  
Vol 26 (1) ◽  
pp. 17-27 ◽  
Author(s):  
Hirohiko Kaneko ◽  
Keiji Uchikawa
Keyword(s):  
Causal Relationship ◽  
Retinal Image ◽  
Binocular Disparity ◽  
Angular Size ◽  
The Other ◽  
Linear Size ◽  
Image Size ◽  
Other Hand

An experiment was conducted to investigate the effects of perspective cue and binocular disparity on perceived angular and linear size. Following the ‘angular’ and ‘linear’ instructions, subjects matched the size of two squares, for which the binocular disparity between the centers of the squares and the configuration of the stimulus surrounding the squares were manipulated. Results showed that angular-size matches depended on the retinal-image size and the binocular disparity, and not on the visual-surround stimulus. Linear-size matches, on the other hand, depended on the visual-surround stimulus as well as on the image size and the binocular disparity. The visual-surround stimulus also affects the perceived depth between the test squares. These findings indicate that perceived angular and linear size depend on different processes that use different cues, and suggest that there is a causal relationship between perceived depth and perceived linear size.

scholarly journals Joint tuning for direction of motion and binocular disparity in macaque MT is largely separable

2013 ◽  
Vol 110 (12) ◽  
pp. 2806-2816 ◽  
Author(s):  
Alexandra Smolyanskaya ◽  
Douglas A. Ruff ◽  
Richard T. Born
Keyword(s):  
Binocular Disparity ◽  
Neuronal Population ◽  
Two Dimensions ◽  
The Other ◽  
Decoding Algorithms ◽  
Mt Neurons ◽  
Multiple Dimensions ◽  
Columnar Organization ◽  
Depth Cue ◽  
Tuning Function

Neurons in sensory cortical areas are tuned to multiple dimensions, or features, of their sensory space. Understanding how single neurons represent multiple features is of great interest for determining the informative dimensions of the neurons' response, the decoding algorithms appropriate for extracting this information from the neuronal population, and for determining where specific transformations occur along the visual hierarchy. Despite the established role of cortical area MT in judgments of motion and depth, it is not known how individual neurons jointly encode the two dimensions. We investigated the joint tuning of individual MT neurons for two visual features: direction of motion and binocular disparity, an important depth cue. We found that a separable, multiplicative combination of tuning for the two features can account for more than 90% of the variance in the joint tuning function for over 91% of MT neurons. These results suggest 1) that each feature can be read out independently from MT by simply averaging across the population without regard to the other feature and 2) that the inseparable representations seen in subsequent areas, such as MST, must be computed beyond MT. Intriguingly, we found that the remaining nonseparable component of the joint tuning function often manifested as small but systematic changes in the neurons' preferences for one feature as the other one was varied. We believe this reflects the local columnar organization of tuning for direction and binocular disparity in MT, indicating that joint tuning may provide a new tool with which to probe functional architecture.

scholarly journals Coexistence of binocular integration and suppression determined by surface border information

2009 ◽  
Vol 106 (37) ◽  
pp. 15990-15995 ◽  
Author(s):  
Yong Su ◽  
Zijiang J. He ◽  
Teng Leng Ooi
Keyword(s):  
Visual Perception ◽  
Binocular Disparity ◽  
Visual Awareness ◽  
The Other ◽  
Inhibitory Process ◽  
Integration Process ◽  
Patch Area ◽  
Vertical Grating ◽  
Circular Grating ◽  
The Brain

The visual system relies on both the integration and interocular inhibitory processes to achieve single vision from different images in the two eyes. It is generally assumed that the integration process first searches for matching local features between the two eyes. If the matching fails, an interocular inhibitory process is triggered to suppress the image representation of one eye, leading to visual perception that is essentially contributed by the other eye. Here, using a stimulus comprising of binocularly corresponding features (vertical gratings) but incompatible surface border information, we found evidence to the contrary. In one half-image, a circular patch of vertical grating was phase-shifted relative to the surrounding vertical grating to create a circular, monocular boundary contour (MBC), while the other half-image had a similar vertical grating. The two half-images had a binocular disparity at the circular grating patch area, leading to the percept of a disc in depth. Concurrent with the stereo percept, threshold for detecting a Gabor probe on the half-image without the MBC was higher than that on the corresponding area with the grating disc, indicating binocular suppression. These findings reveal that when we perceive depth, which requires the integration process to obtain binocular disparity from the two eyes, one eye's image could simultaneously be suppressed from visual awareness by the interocular inhibitory process. Our study also presents a provocative example of where the brain selectively binds some, but not all, features of the images from the two eyes for visual perception.

scholarly journals Asymmetries during face encoding: Increaded dwell time and number of fixations in the upper visual hemifield

2018 ◽  
Author(s):  
Fatima Maria Felisberti
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Dwell Time ◽  
The Other ◽  
Environmental Cues ◽  
Reading Habits ◽  
Visual Hemifield ◽  
Bottom Left

Visual field asymmetries (VFAs) in the encoding of groups of faces has rarely been investigated. Here, eye movements (proportion of dwell time (pDT) and number of fixations (nFix)) were recorded during the encoding of three groups of four faces tagged with cheating, cooperative, or neutral behaviours. Faces in each group were placed either in the top left, top right, bottom left, or bottom right quadrants. Face recall was equally high in the three behavioural groups. Conversely, pDT and nFix were higher for faces in the upper hemifields. Most of the first saccades were made to the top left visual quadrant, which also commanded a higher pDT and nFix than the other quadrants. The findings are relevant to the understanding of VFAs in the processing of multiple faces, a common social scenario, and may be linked to reading habits in conjunction (or not) with cultural and environmental cues.

Dmax for Stereoscopic Depth Perception with Simulated Monovision Correction

2012 ◽  
Vol 25 (5) ◽  
pp. 399-408 ◽  
Author(s):  
Jin Qian ◽  
Samuel A. Adeseye ◽  
Scott B. Stevenson ◽  
Saumil S. Patel ◽  
Harold E. Bedell
Keyword(s):  
Depth Perception ◽  
Binocular Disparity ◽  
Binocular Viewing ◽  
The Other ◽  
Stereoscopic Depth ◽  
Clear Image ◽  
Random Line ◽  
Low Pass ◽  
Blurred Image ◽  
Line Patterns

Purpose: Persons who wear monovision correction typically receive a clear image in one eye and a blurred image in the other eye. Although monovision is known to elevate the minimum stereoscopic threshold (Dmin), it is uncertain how it influences the largest binocular disparity for which the direction of depth can reliably be perceived (Dmax). In this study, we comparedDmaxfor stereo when one eye’s image is blurred toDmaxwhen both eyes’ images are either clear or blurred.Methods: The stimulus was a pair of vertically oriented, random-line patterns. To simulate monovision correction with +1.5 or +2.5 D defocus, the images of the line patterns presented to one eye were spatially low-pass filtered while the patterns presented to the other eye remained unfiltered.Results: Compared to binocular viewing without blur,Dminis elevated substantially more in the presence of monocular than binocular simulated blur.Dmaxis reduced in the presence of simulated monocular blur by between 13 and 44%, compared to when the images in both eyes are clear. In contrast, when the targets presented to both eyes are blurred equally,Dmaxeither is unchanged or increases slightly, compared to the values measured with no blur.Conclusion: In conjunction with the elevation ofDmin, the reduction ofDmaxwith monocular blur indicates that the range of useful stereoscopic depth perception is likely to be compressed in patients who wear monovision corrections.

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