Revealing Visual Information Use Through Random Sampling of Spatial Frequencies and Orientations

Our perception of an object’s size arises from the integration of multiple sources of visual information including retinal size, perceived distance and its size relative to other objects in the visual field. This constructive process is revealed through a number of classic size illusions such as the Delboeuf Illusion, the Ebbinghaus Illusion and others illustrating size constancy. Here we present a novel variant of the Delbouef and Ebbinghaus size illusions that we have named the Binding Ring Illusion. The illusion is such that the perceived size of a circular array of elements is underestimated when superimposed by a circular contour – a binding ring – and overestimated when the binding ring slightly exceeds the overall size of the array. Here we characterize the stimulus conditions that lead to the illusion, and the perceptual principles that underlie it. Our findings indicate that the perceived size of an array is susceptible to the assimilation of an explicitly defined superimposed contour. Our results also indicate that the assimilation process takes place at a relatively high level in the visual processing stream, after different spatial frequencies have been integrated and global shape has been constructed. We hypothesize that the Binding Ring Illusion arises due to the fact that the size of an array of elements is not explicitly defined and therefore can be influenced (through a process of assimilation) by the presence of a superimposed object that does have an explicit size.

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Spatial Scale Interactions and Visual-Tracking Performance

Perception ◽

10.1068/p261047 ◽

1997 ◽

Vol 26 (8) ◽

pp. 1047-1058 ◽

Cited By ~ 1

Author(s):

Howard C Hughes ◽

David M Aronchick ◽

Michael D Nelson

Keyword(s):

Spatial Frequency ◽

High Frequency ◽

Visual Information ◽

Low Frequency ◽

High Spatial Frequency ◽

Performance Measure ◽

High Frequency Component ◽

Stimulus Velocity ◽

Spatial Frequencies ◽

Wide Range

It has previously been observed that low spatial frequencies (≤ 1.0 cycles deg−1) tend to dominate high spatial frequencies (≥ 5.0 cycles deg−1) in several types of visual-information-processing tasks. This earlier work employed reaction times as the primary performance measure and the present experiments address the possibility of low-frequency dominance by evaluating visually guided performance of a completely different response system: the control of slow-pursuit eye movements. Slow-pursuit gains (eye velocity/stimulus velocity) were obtained while observers attempted to track the motion of a sine-wave grating. The drifting gratings were presented on three types of background: a uniform background, a background consisting of a stationary grating, or a flickering background. Low-frequency dominance was evident over a wide range of velocities, in that a stationary high-frequency component produced little disruption in the pursuit of a drifting low spatial frequency, but a stationary low frequency interfered substantially with the tracking of a moving high spatial frequency. Pursuit was unaffected by temporal modulation of the background, suggesting that these effects are due to the spatial characteristics of the stationary grating. Similar asymmetries were observed with respect to the stability of fixation: active fixation was less stable in the presence of a drifting low frequency than in the presence of a drifting high frequency.

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Managing Level of Detail in Virtual Environments: A Perceptual Framework

Presence Teleoperators & Virtual Environments ◽

10.1162/pres.1997.6.6.658 ◽

1997 ◽

Vol 6 (6) ◽

pp. 658-666 ◽

Cited By ~ 11

Author(s):

Martin Reddy ◽

Benjamin Watson ◽

Neff Walker ◽

Larry F. Hodges

Keyword(s):

Virtual Environments ◽

Visual Information ◽

Companion Paper ◽

Sensitivity Function ◽

Level Of Detail ◽

Human Vision ◽

Immersive Virtual Reality ◽

Visual Change ◽

Visual Detail ◽

Spatial Frequencies

In the companion paper, Watson et al. (1997), we demonstrated the effectiveness of using perceptual criteria to select the amount of detail that is displayed in an immersive virtual reality (VR) system. Based upon this determination, we will now attempt to develop a principled, perceptually oriented framework to automatically select the appropriate level of detail (LOD) for each object in a scene, taking into consideration the limitations of the human visual system. We apply knowledge and theories from the domain of visual perception to the field of VR, thus optimizing the visual information presented to the user based upon solid metrics of human vision. Through a series of contrast grating experiments, a user's visual acuity may be assessed in terms of spatial frequency (c/deg) and contrast. The results of these tests can be modeled mathematically using a contrast sensitivity function (CSF). Therefore, we can use the CSF results to estimate how much visual detail the user can perceive in an object at any instant. Then, if we could describe this object in terms of its spatial frequencies, this would enable us to select the lowest LOD available without the user being able to perceive any visual change.

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Dynamic Electrode-to-Image (DETI) mapping reveals the human brain’s spatiotemporal code of visual information

PLoS Computational Biology ◽

10.1371/journal.pcbi.1009456 ◽

2021 ◽

Vol 17 (9) ◽

pp. e1009456

Author(s):

Bruce C. Hansen ◽

Michelle R. Greene ◽

David J. Field

Keyword(s):

Temporal Resolution ◽

Visual Information ◽

Mapping Technique ◽

High Temporal Resolution ◽

Visual Code ◽

Neural Signals ◽

Future Studies ◽

Spatial Frequencies ◽

High Level ◽

Neuroimaging Techniques

A number of neuroimaging techniques have been employed to understand how visual information is transformed along the visual pathway. Although each technique has spatial and temporal limitations, they can each provide important insights into the visual code. While the BOLD signal of fMRI can be quite informative, the visual code is not static and this can be obscured by fMRI’s poor temporal resolution. In this study, we leveraged the high temporal resolution of EEG to develop an encoding technique based on the distribution of responses generated by a population of real-world scenes. This approach maps neural signals to each pixel within a given image and reveals location-specific transformations of the visual code, providing a spatiotemporal signature for the image at each electrode. Our analyses of the mapping results revealed that scenes undergo a series of nonuniform transformations that prioritize different spatial frequencies at different regions of scenes over time. This mapping technique offers a potential avenue for future studies to explore how dynamic feedforward and recurrent processes inform and refine high-level representations of our visual world.

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Spatial Frequency Thresholds for Detecting Latent Facial Signals of Threat

Perception ◽

10.1177/0301006619828254 ◽

2019 ◽

Vol 48 (3) ◽

pp. 214-227

Author(s):

Nicholas Watier ◽

Brock DeGagne

Keyword(s):

Spatial Frequency ◽

Face Processing ◽

Visual Information ◽

Forced Choice ◽

Face Identification ◽

Staircase Procedure ◽

Spatial Frequencies

This study examined whether latent facial signals of threat can be detected at more extreme ranges of spatial frequencies (SFs), and thus with fewer frequencies from an optimal middle band for face identification, compared with latent nonthreatening facial signals. Using an adaptive staircase procedure and a two-interval forced-choice same-different task, SF thresholds from the lower and higher ends of the SF spectrum were obtained for nonexpressive threatening and nonthreatening faces. Threatening faces were discriminated from neutral faces more quickly and accurately, and engendered more extreme SF thresholds, compared with nonthreatening faces. The results indicate that the components of latent threatening facial signals can be detected under a greater degree of impoverished visual information for face processing compared with their nonthreatening counterparts.

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Dynamics of spatial frequency tuning in mouse visual cortex

Journal of Neurophysiology ◽

10.1152/jn.00022.2012 ◽

2012 ◽

Vol 107 (11) ◽

pp. 2937-2949 ◽

Cited By ~ 7

Author(s):

Samme Vreysen ◽

Bin Zhang ◽

Yuzo M. Chino ◽

Lutgarde Arckens ◽

Gert Van den Bergh

Keyword(s):

Visual Cortex ◽

Spatial Frequency ◽

Visual Information ◽

Frequency Tuning ◽

Neuronal Response ◽

Correlation Technique ◽

Low Frequencies ◽

Temporal Shift ◽

Spatial Frequency Tuning ◽

Spatial Frequencies

Neuronal spatial frequency tuning in primary visual cortex (V1) substantially changes over time. In both primates and cats, a shift of the neuron's preferred spatial frequency has been observed from low frequencies early in the response to higher frequencies later in the response. In most cases, this shift is accompanied by a decreased tuning bandwidth. Recently, the mouse has gained attention as a suitable animal model to study the basic mechanisms of visual information processing, demonstrating similarities in basic neuronal response properties between rodents and highly visual mammals. Here we report the results of extracellular single-unit recordings in the anesthetized mouse where we analyzed the dynamics of spatial frequency tuning in V1 and the lateromedial area LM within the lateral extrastriate area V2L. We used a reverse-correlation technique to demonstrate that, as in monkeys and cats, the preferred spatial frequency of mouse V1 neurons shifted from low to higher frequencies later in the response. However, this was not correlated with a clear selectivity increase or enhanced suppression of responses to low spatial frequencies. These results suggest that the neuronal connections responsible for the temporal shift in spatial frequency tuning may considerably differ between mice and monkeys.

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Measuring Early Cortical Visual Processing in the Clinic

i-Perception ◽

10.1177/2041669517702915 ◽

2017 ◽

Vol 8 (3) ◽

pp. 204166951770291

Author(s):

Linda Bowns ◽

William H.A. Beaudot

Keyword(s):

Visual Processing ◽

Visual Information ◽

Mobile App ◽

The Other ◽

Air Traffic Controllers ◽

Spatial Frequencies ◽

Integration Test ◽

Pattern Motion ◽

Component Extraction ◽

Cortical Visual Processing

We describe a mobile app that measures early cortical visual processing suitable for use in clinics. The app is called Component Extraction and Motion Integration Test (CEMIT). Observers are asked to respond to the direction of translating plaids that move in one of two very different directions. The plaids have been selected so that the plaid components move in one of the directions and the plaid pattern moves in the other direction. In addition to correctly responding to the pattern motion, observers demonstrate their ability to correctly extract the movement (and therefore the orientation) of the underlying components at specific spatial frequencies. We wanted to test CEMIT by seeing if we could replicate the broader tuning observed at low spatial frequencies for this type of plaid. Results from CEMIT were robust and successfully replicated this result for 50 typical observers. We envisage that it will be of use to researchers and clinicians by allowing them to investigate specific deficits at this fundamental level of cortical visual processing. CEMIT may also be used for screening purposes where visual information plays an important role, for example, air traffic controllers.

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Contingency in Visual Scanning of Cockpit Traffic Displays

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/154193128202601122 ◽

1982 ◽

Vol 26 (11) ◽

pp. 1005-1009 ◽

Cited By ~ 1

Author(s):

Stephen R. Ellis

Keyword(s):

Statistical Method ◽

Random Sampling ◽

Visual Information ◽

Traffic Information ◽

Stratified Random Sampling ◽

Position Information ◽

Airline Pilots ◽

Points Of Interest ◽

Cockpit Displays ◽

Visual Fixations

A statistical method to identify reliable, repetitive scanning patterns in the positions of visual fixations has been developed and applied to data from 8 airline pilots who monitored cockpit displays of traffic information (CDTI). Their fixational transition patterns between points of interest on the display showed deterministic, statistical dependencies generally associated with symbols predicting future aircraft position. These dependencies constitute deviations from stratified random sampling of the visual information on the display, confirm the importance of future aircraft position information for the use of CDTI, and provide objective support for the existence of “scanpaths” in visual fixation patterns.

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Channeling of red and green cone inputs to the zebrafish optomotor response

Visual Neuroscience ◽

10.1017/s0952523805223039 ◽

2005 ◽

Vol 22 (3) ◽

pp. 275-281 ◽

Cited By ~ 81

Author(s):

MICHAEL B. ORGER ◽

HERWIG BAIER

Keyword(s):

Visual Information ◽

Vertebrate Species ◽

Optomotor Response ◽

Color Information ◽

Form Vision ◽

Form Processing ◽

Larval Zebrafish ◽

Spatial Frequencies ◽

Sinusoidal Gratings ◽

Input Strength

Visual systems break scenes down into individual features, processed in distinct channels, and then selectively recombine those features according to the demands of particular behavioral tasks. In primates, for example, there are distinct pathways for motion and form processing. While form vision utilizes color information, motion pathways receive input from only a subset of cone photoreceptors and are generally colorblind. To explore the link between early channeling of visual information and behavioral output across vertebrate species, we measured the chromatic inputs to the optomotor response of larval zebrafish. Using cone-isolating gratings, we found that there is a strong input from both red and green cones but not short-wavelength cones, which nevertheless do contribute to another behavior, phototaxis. Using a motion-nulling method, we measured precisely the input strength of gratings that stimulated cones in combination. The fish do not respond to gratings that stimulate different cone types out of phase, but have an enhanced response when the cones are stimulated together. This shows that red and green cone signals are pooled at a stage before motion detection. Since the two cone inputs are combined into a single ‘luminance’ channel, the response to sinusoidal gratings is colorblind. However, we also find that the relative contributions of the two cones at isoluminance varies with spatial frequency. Therefore, natural stimuli, which contain a mixture of spatial frequencies, are likely to be visible regardless of their chromatic composition.

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