scholarly journals Stereoanomaly for crossed disparity in the upper visual field and uncrossed disparity in the lower visual field

2013 ◽  
Vol 13 (9) ◽  
pp. 1179-1179
Author(s):  
A. Yasuoka ◽  
M. Ishii ◽  
S. Matsuda
Keyword(s):  
Visual Field ◽  
Lower Visual Field ◽  
Upper Visual Field ◽  
Uncrossed Disparity

scholarly journals Mouse retinal specializations reflect knowledge of natural environment statistics

2020 ◽  
Author(s):  
Yongrong Qiu ◽  
Zhijian Zhao ◽  
David Klindt ◽  
Magdalena Kautzky ◽  
Klaudia P. Szatko ◽  
...  
Keyword(s):  
Visual Field ◽  
Visual Processing ◽  
Natural Scenes ◽  
Lower Visual Field ◽  
Natural Scene Statistics ◽  
Predator Detection ◽  
Chromatic Contrast ◽  
Enhanced Sensitivity ◽  
Upper Visual Field ◽  
Environmental Difference

SummaryPressures for survival drive sensory circuit adaption to a species’ habitat, making it essential to statistically characterise natural scenes. Mice, a prominent visual system model, are dichromatic with enhanced sensitivity to green and UV. Their visual environment, however, is rarely considered. Here, we built a UV-green camera to record footage from mouse habitats. We found chromatic contrast to greatly diverge in the upper but not the lower visual field, an environmental difference that may underlie the species’ superior colour discrimination in the upper visual field. Moreover, training an autoencoder on upper but not lower visual field scenes was sufficient for the emergence of colour-opponent filters. Furthermore, the upper visual field was biased towards dark UV contrasts, paralleled by more light-offset-sensitive cells in the ventral retina. Finally, footage recorded at twilight suggests that UV promotes aerial predator detection. Our findings support that natural scene statistics shaped early visual processing in evolution.Lead contactFurther information and requests for resources and reagents should be directed to and will be fulfilled by the Lead Contact, Thomas Euler ([email protected])

scholarly journals Dyslexic children show altered temporal structure of the nonlinear VEP

2019 ◽  
Author(s):  
Sheila Crewther ◽  
Jacqueline Rutkowski ◽  
David Crewther
Keyword(s):  
Visual Field ◽  
Change Detection ◽  
Second Order ◽  
Lower Visual Field ◽  
Perceptual Speed ◽  
Auditory Temporal Processing ◽  
Low Contrast ◽  
First Order ◽  
Upper Visual Field ◽  
Order Kernel

AbstractThe neural basis of dyslexia remains unresolved, despite many theories relating dyslexia to dysfunction in visual magnocellular and auditory temporal processing, cerebellar dysfunction, attentional deficits, as well as excessive neural noise. Recent research identifies perceptual speed as a common factor, integrating several of these systems. Optimal perceptual speed invokes transient attention as a necessary component, and change detection in gap paradigm tasks is impaired in those with dyslexia. This research has also identified an overall better change detection for targets presented in the upper compared with lower visual fields. Despite the magnocellular visual pathway being implicated in the aetiology of dyslexia over 30 years ago, objective physiological measures have been lacking. Thus, we employed nonlinear visual evoked potential (VEP) techniques which generate second order kernel terms specific for magno and parvocellular processing as a means to assessing the physiological status of poor readers (PR, n=12) compared with good readers (GR, n=16) selected from children with a mean age of 10yr. The first and second order Wiener kernels using multifocal VEP were recorded from a 4° foveal stimulus patch as well as for upper and lower visual field peripheral arcs. Foveal responses showed little difference between GR and PR for low contrast stimulation, except for the second slice of the second order kernel where lower peak amplitudes were recorded for PR vs GR. At high contrast, there was a trend to smaller first order kernel amplitudes for short latency peaks of the PR vs GR. In addition, there were significant latency differences for the first negativity in the first two slices of the second order kernel. In terms of peripheral stimulation, lower visual field response amplitudes were larger compared with upper visual field responses, for both PR and GR. A trend to larger second/first order ratio for magnocellularly driven responses suggests the possibility of lesser neural efficiency in the periphery for the PR compared with the GR. Stronger lower field peripheral response may relate to better upper visual field change detection performance when target visibility is controlled through flicking masks. In conclusion, early cortical magnocellular processing at low contrast was normal in those with dyslexia, while cortical activity related to parvocellular afferents was reduced. In addition, the study demonstrated a physiological basis for upper versus lower visual field differences related to magnocellular function.

Vertical Visual-Field Differences in Schematic Persistence for Colour Information

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 172-172
Author(s):  
B Heider ◽  
R Groner
Keyword(s):  
Visual Field ◽  
Visual Fields ◽  
Field Performance ◽  
Partial Report ◽  
Lower Visual Field ◽  
Circular Array ◽  
Verbal Information ◽  
Upper Visual Field ◽  
Original Target ◽  
Verbal Content

The functional specialisation in the upper and lower visual fields is related to the distinction between far and near vision, and may parallel differences between the ventral and dorsal processing streams. Here, we studied possible differences in colour processing. According to postulates of Previc (1990 Behavioral and Brain Sciences13 519 – 575), we expected longer persistence and an advantage in colour classification for stimuli presented in the upper visual field. Performance was tested in a modified partial-report task to estimate duration of schematic persistence for colour and verbal information. The targets were letter strings—either red, yellow, blue, or green—presented in three combinations: (a) nonsense strings, (b) congruent colour-words, and (c) incongruent colour-words. Eight targets were simultaneously presented in a circular array for 60 ms. After a variable interstimulus interval (ISI, 0 – 900 ms), a coloured marker was briefly displayed pointing to one of the original target positions, and the participants had to report whether the colours of target and marker were identical or not. The responses were analysed separately for upper and lower visual-field presentations. The verbal content of the targets did not affect performance. There were no differences in performance between the two visual fields. However, analyses of both accuracy and reaction latencies showed significant interactions between visual field and ISI, ie performance decreased at a slower rate in the upper visual field. These results suggest longer schematic persistence for colour stimuli presented in the upper visual field.

scholarly journals Typical retinotopic locations impact the time course of object coding

2017 ◽  
Author(s):  
Daniel Kaiser ◽  
Merle M. Moeskops ◽  
Radoslaw M. Cichy
Keyword(s):  
Visual Field ◽  
Time Course ◽  
Visual Space ◽  
Neural Mechanism ◽  
Natural Environments ◽  
Lower Visual Field ◽  
Object Processing ◽  
Upper Visual Field ◽  
Long Term Experience

AbstractIn everyday visual environments, objects are non-uniformly distributed across visual space. Many objects preferentially occupy particular retinotopic locations: for example, lamps more often fall into the upper visual field, whereas carpets more often fall into the lower visual field. The long-term experience with natural environments prompts the hypothesis that the visual system is tuned to such retinotopic object locations. A key prediction is that typically positioned objects should be coded more efficiently. To test this prediction, we recorded electroencephalography (EEG) while participants viewed briefly presented objects appearing in their typical locations (e.g., an airplane in the upper visual field) or in atypical locations (e.g., an airplane in the lower visual field). Multivariate pattern analysis applied to the EEG data revealed that object classification depended on positional regularities: Objects were classified more accurately when positioned typically, rather than atypically, already at 140 ms, suggesting that relatively early stages of object processing are tuned to typical retinotopic locations. Our results confirm the prediction that long-term experience with objects occurring at specific locations leads to enhanced perceptual processing when these objects appear in their typical locations. This may indicate a neural mechanism for efficient natural scene processing, where a large number of typically positioned objects needs to be processed.

scholarly journals Typical visual-field locations enhance processing in object-selective channels of human occipital cortex

2018 ◽  
Vol 120 (2) ◽  
pp. 848-853 ◽  
Author(s):  
Daniel Kaiser ◽  
Radoslaw M. Cichy
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Functional Mri ◽  
Object Perception ◽  
Occipital Cortex ◽  
Natural Environments ◽  
Lower Visual Field ◽  
Cortical Processing ◽  
Upper Visual Field ◽  
Early Visual Cortex

Natural environments consist of multiple objects, many of which repeatedly occupy similar locations within a scene. For example, hats are seen on people’s heads, while shoes are most often seen close to the ground. Such positional regularities bias the distribution of objects across the visual field: hats are more often encountered in the upper visual field, while shoes are more often encountered in the lower visual field. Here we tested the hypothesis that typical visual field locations of objects facilitate cortical processing. We recorded functional MRI while participants viewed images of objects that were associated with upper or lower visual field locations. Using multivariate classification, we show that object information can be more successfully decoded from response patterns in object-selective lateral occipital cortex (LO) when the objects are presented in their typical location (e.g., shoe in the lower visual field) than when they are presented in an atypical location (e.g., shoe in the upper visual field). In a functional connectivity analysis, we relate this benefit to increased coupling between LO and early visual cortex, suggesting that typical object positioning facilitates information propagation across the visual hierarchy. Together these results suggest that object representations in occipital visual cortex are tuned to the structure of natural environments. This tuning may support object perception in spatially structured environments. NEW & NOTEWORTHY In the real world, objects appear in predictable spatial locations. Hats, commonly appearing on people’s heads, often fall into the upper visual field. Shoes, mostly appearing on people’s feet, often fall into the lower visual field. Here we used functional MRI to demonstrate that such regularities facilitate cortical processing: Objects encountered in their typical locations are coded more efficiently, which may allow us to effortlessly recognize objects in natural environments.

scholarly journals Asymmetrical representation of the upper and lower visual fields in oculomotor maps

2016 ◽  
Author(s):  
Zhiguo Wang ◽  
Benchi Wang ◽  
Matthew Finkbeiner
Keyword(s):  
Visual Field ◽  
Visual Fields ◽  
Saccade Target ◽  
Lower Visual Field ◽  
Visually Guided ◽  
Fixation Stimulus ◽  
Visual Distractor ◽  
Upper Visual Field ◽  
Striate Area

The striate area devoted to the lower visual field (LVF) is larger than that devoted to the upper visual field (UVF). A similar anatomical asymmetry also exists in the LGN. Here we take advantage of two experimental tasks that are known to modulate the direction and amplitude of saccades to demonstrate a visual field asymmetry in oculomotor maps. Participants made visually guided saccades. In Experiment 1, the saccade target was accompanied by a visual distractor. The distractor's presence modulated the direction of saccades, and this effect was much stronger for LVF targets. In Experiment 2, the temporal gap between the offset of the fixation stimulus and the onset of the saccade target was manipulated. This manipulation modulated the amplitude of saccades and this modulation was stronger for saccades towards UVF targets. Taken together, these results suggest that the representation of both meridians and eccentricities in the LVF is compressed in oculomotor maps.

Visual field inhomogeneous in brain-computer interfaces based on rapid serial visual presentation

2022 ◽  
Author(s):  
Shangen Zhang ◽  
Xiaogang Chen ◽  
Yijun Wang ◽  
Baolin Liu ◽  
Xiaorong Gao
Keyword(s):  
Visual Field ◽  
Visual Attention ◽  
Rapid Serial Visual Presentation ◽  
Visual Fields ◽  
Visual Presentation ◽  
Lower Visual Field ◽  
Horizontal Meridian ◽  
Vertical Meridian ◽  
Upper Visual Field ◽  
Better Than

Abstract Objective. Visual attention is not homogeneous across the visual field, while how to mine the effective EEG characteristics that are sensitive to the inhomogeneous of visual attention and further explore applications such as the performance of brain-computer interface (BCI) are still distressing explorative scientists. Approach. Images were encoded into a rapid serial visual presentation (RSVP) paradigm, and were presented in three visuospatial patterns (central, left/right, upper/lower) at the stimulation frequencies of 10Hz, 15Hz and 20Hz. The comparisons among different visual fields were conducted in the dimensions of subjective behavioral and EEG characteristics. Furthermore, the effective features (e.g. SSVEP, N2pc and P300) that sensitive to visual-field asymmetry were also explored. Results. The visual fields had significant influences on the performance of RSVP target detection, in which the performance of central was better than that of peripheral visual field, the performance of horizontal meridian was better than that of vertical meridian, the performance of left visual field was better than that of right visual field, and the performance of upper visual field was better than that of lower visual field. Furthermore, stimuli of different visual fields had significant effects on the spatial distributions of EEG, in which N2pc and P300 showed left-right asymmetry in occipital and frontal regions, respectively. In addition, the evidences of SSVEP characteristics indicated that there was obvious overlap of visual fields on the horizontal meridian, but not on the vertical meridian. Significance. The conclusions of this study provide insights into the relationship between visual field inhomogeneous and EEG characteristics. In addition, this study has the potential to achieve precise positioning of the target's spatial orientation in RSVP-BCIs.

Modulation of Sensory Suppression: Implications for Receptive Field Sizes in the Human Visual Cortex

2001 ◽  
Vol 86 (3) ◽  
pp. 1398-1411 ◽  
Author(s):  
Sabine Kastner ◽  
Peter De Weerd ◽  
Mark A. Pinsk ◽  
M. Idette Elizondo ◽  
Robert Desimone ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Receptive Field ◽  
Neural Representation ◽  
Lower Visual Field ◽  
Human Visual Cortex ◽  
Area V4 ◽  
Upper Visual Field ◽  
Neurophysiological Studies ◽  
Extrastriate Areas

Neurophysiological studies in monkeys show that when multiple visual stimuli appear simultaneously in the visual field, they are not processed independently, but rather interact in a mutually suppressive way. This suggests that multiple stimuli compete for neural representation. Consistent with this notion, we have previously found in humans that functional magnetic resonance imaging (fMRI) signals in V1 and ventral extrastriate areas V2, V4, and TEO are smaller for simultaneously presented (i.e., competing) stimuli than for the same stimuli presented sequentially (i.e., not competing). Here we report that suppressive interactions between stimuli are also present in dorsal extrastriate areas V3A and MT, and we compare these interactions to those in areas V1 through TEO. To exclude the possibility that the differences in responses to simultaneously and sequentially presented stimuli were due to differences in the number of transient onsets, we tested for suppressive interactions in area V4, in an experiment that held constant the number of transient onsets. We found that the fMRI response to a stimulus in the upper visual field was suppressed by the presence of nearby stimuli in the lower visual field. Further, we excluded the possibility that the greater fMRI responses to sequential compared with simultaneous presentations were due to exogeneous attentional cueing by having our subjects count T's or L's at fixation, an attentionally demanding task. Behavioral testing demonstrated that neither condition interfered with performance of the T/L task. Our previous findings suggested that suppressive interactions among nearby stimuli in areas V1 through TEO were scaled to the receptive field (RF) sizes of neurons in those areas. Here we tested this idea by parametrically varying the spatial separation among stimuli in the display. Display sizes ranged from 2 × 2° to 7 × 7° and were centered at 5.5° eccentricity. Based on the effects of display size on the magnitude of suppressive interactions, we estimated that RF sizes at an eccentricity of 5.5° were <2° in V1, 2–4° in V2, 4–6° in V4, larger than 7° (but still confined to a quadrant) in TEO, and larger than 6° (confined to a quadrant) in V3A. These estimates of RF sizes in human visual cortex are strikingly similar to those measured in physiological mapping studies in the homologous visual areas in monkeys.

scholarly journals Asymmetry in Gaze Direction Discrimination Between the Upper and Lower Visual Fields

Perception ◽  
2017 ◽  
Vol 46 (8) ◽  
pp. 941-955 ◽  
Author(s):  
Adam Palanica ◽  
Roxane J. Itier
Keyword(s):  
Visual Field ◽  
Visual Fields ◽  
Discrimination Performance ◽  
Gaze Direction ◽  
Head Orientation ◽  
Lower Visual Field ◽  
Foveal Vision ◽  
Vertical Meridian ◽  
Upper Visual Field ◽  
Central Fixation

Previous research has shown that gaze direction can only be accurately discriminated within parafoveal limits (∼5° eccentricity) along the horizontal visual field. Beyond this eccentricity, head orientation seems to influence gaze discrimination more than iris cues. The present study examined gaze discrimination performance in the upper visual field (UVF) and lower visual field (LVF), and whether head orientation affects gaze judgments beyond parafoveal vision. Direct and averted gaze faces, in frontal and deviated head orientations, were presented for 150 ms along the vertical meridian while participants maintained central fixation during gaze discrimination judgments. Gaze discrimination was above chance level at all but one eccentricity for the two gaze-head congruent conditions. In contrast, for the incongruent conditions, gaze was discriminated above chance only from –1.5° to +3°, with an asymmetry between the UVF and LVF. Beyond foveal vision, response rates were biased toward head orientation rather than iris eccentricity, occurring in the LVF for both head orientations, and in the UVF for frontal head views. These findings suggest that covert processing of gaze direction involves the integration of eyes and head cues, with congruency of these two social cues driving response differences between the LVF and the UVF.

scholarly journals Shorter fixation durations for up-directed saccades during saccadic exploration: A meta-analysis

2020 ◽  
Vol 12 (8) ◽  
Author(s):  
Harold H. Greene ◽  
James M. Brown ◽  
Gregory P. Strauss
Keyword(s):  
Visual Field ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Lower Visual Field ◽  
Visual Displays ◽  
Eye Fixation ◽  
Fixation Durations ◽  
Upper Visual Field ◽  
Saccade Direction ◽  
The Asymmetry

Utilizing 23 datasets, we report a meta-analysis of an asymmetry in presaccadic fixation durations for saccades directed above and below eye fixation during saccadic exploration. For inclusion in the meta-analysis, saccadic exploration of complex visual displays had to have been made without gaze-contingent manipulations. Effect sizes for the asymmetry were quantified as Hedge’s g. Pooled effect sizes indicated significant asymmetries such that during saccadic exploration in a variety of tasks, presaccadic fixation durations for saccades directed into the upper visual field were reliably shorter than presaccadic fixation durations for saccades into the lower visual field. It is contended that the asymmetry is robust and important for efforts aimed at modelling when a saccade is initiated as a function of ensuing saccade direction.

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