Judging Egocentric Distance on the Ground: Occlusion and Surface Integration

Perception ◽  
2004 ◽  
Vol 33 (7) ◽  
pp. 789-806 ◽  
Author(s):  
Zijiang J He ◽  
Bing Wu ◽  
Teng Leng Ooi ◽  
Gary Yarbrough ◽  
Jun Wu
Keyword(s):  
Egocentric Distance ◽  
Surface Integration

Inaccurate Space Perception Seeing Through Fences

Perception ◽  
2020 ◽  
Vol 49 (9) ◽  
pp. 926-939
Author(s):  
Bo Dong ◽  
Airui Chen ◽  
Yuting Zhang ◽  
Changchun Li ◽  
Tianyang Zhang ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Visual Angle ◽  
Daily Life ◽  
Ground Surface ◽  
Space Perception ◽  
Vital Role ◽  
Target Size ◽  
Integration Process ◽  
Egocentric Distance ◽  
Surface Integration

According to the sequential surface integration process hypothesis, the fine near-ground-surface representation and the homogeneous ground surface play a vital role in the representation of the ground surface. When an occluding box or opaque wall is placed between observers and targets, observers underestimate egocentric distance. However, in our daily life, many obstacles are perforated and cover the ground surface and targets simultaneously (e.g., fences). Humans see and observe through fences. The images of these fences and targets, projected onto observers’ retinas, overlap each other. This study aims to explore the effects of perforated obstacles (i.e., fences) on space perception. The results showed that observers underestimated the egocentric distances when there was a fence on the ground surface relative to the no-fence condition, and the effect of widely spaced thick wood fences was larger than that of narrowly spaced thin iron fences. We further demonstrated that this effect was quite robust when the target size had a visual angle of 1°, 2°, or 4° in three virtual reality experiments. This study may add support for the notion that the sequential surface integration process hypothesis is applicable even if the obstacle is perforated and covers the target.

scholarly journals The foggy effect of egocentric distance in a nonverbal paradigm

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bo Dong ◽  
Airui Chen ◽  
Yuting Zhang ◽  
Yangyang Zhang ◽  
Ming Zhang ◽  
...  
Keyword(s):  
Distance Perception ◽  
Matching Task ◽  
Egocentric Distance ◽  
Accident Rate ◽  
Estimation Task ◽  
Distance Range ◽  
Verbal Estimation ◽  
Vista Space ◽  
Visual Matching ◽  
Speed Perception

AbstractInaccurate egocentric distance and speed perception are two main explanations for the high accident rate associated with driving in foggy weather. The effect of foggy weather on speed has been well studied. However, its effect on egocentric distance perception is poorly understood. The paradigm for measuring perceived egocentric distance in previous studies was verbal estimation instead of a nonverbal paradigm. In the current research, a nonverbal paradigm, the visual matching task, was used. Our results from the nonverbal task revealed a robust foggy effect on egocentric distance. Observers overestimated the egocentric distance in foggy weather compared to in clear weather. The higher the concentration of fog, the more serious the overestimation. This effect of fog on egocentric distance was not limited to a certain distance range but was maintained in action space and vista space. Our findings confirm the foggy effect with a nonverbal paradigm and reveal that people may perceive egocentric distance more "accurately" in foggy weather than when it is measured with a verbal estimation task.

Three-dimensional time-harmonic elastodynamic Green ’ s functions for anisotropic solids

1995 ◽  
Vol 449 (1937) ◽  
pp. 441-458 ◽  
Keyword(s):  
Differential Equations ◽  
Radon Transform ◽  
Transverse Isotropy ◽  
Three Dimensional ◽  
Surface Integral ◽  
Line Integral ◽  
Surface Integration ◽  
Time Harmonic ◽  
Inverse Radon Transform ◽  
Eigenvectors And Eigenvalues

A method based on the Radon transform is presented to determine the displacement field in a general anisotropic solid due to the application of a time-harmonic point force. The Radon transform reduces the system of coupled partial differential equations for the displacement components to a system of coupled ordinary differential equations. This system is reduced to an uncoupled form by the use of properties of eigenvectors and eigenvalues. The resulting simplified system can be solved easily. A back transformation to the original coordinate system and a subsequent application of the inverse Radon transform yields the displacements as a summation of a regular elastodynamic term and a singular static term. Both terms are integrals over a unit sphere. For the regular dynamic term, the surface integration can be evaluated numerically without difficulty. For the singular static term, the surface integral has been reduced to a line integral over half a unit circle. Reductions to the cases of isotropy and transverse isotropy have been worked out in detail. Examples illustrate applications of the method.

Hypometric Allocentric and Egocentric Distance Estimates in Parkinson Disease

2013 ◽  
Vol 26 (3) ◽  
pp. 133-139 ◽  
Author(s):  
Anahid Kabasakalian ◽  
Tigran Kesayan ◽  
John B. Williamson ◽  
Frank M. Skidmore ◽  
Adam D. Falchook ◽  
...  
Keyword(s):  
Parkinson Disease ◽  
Egocentric Distance

Doppler flow measurement using surface integration of velocity vectors (Sivv): in vitro validation

2000 ◽  
Vol 26 (2) ◽  
pp. 255-262 ◽  
Author(s):  
Michelle S Chew ◽  
Joakim Brandberg ◽  
Peter Canard ◽  
Erik Sloth ◽  
Per Ask ◽  
...  
Keyword(s):  
Flow Measurement ◽  
Doppler Flow ◽  
Surface Integration

scholarly journals How stable are the collagen and ferritin proteins for application in bioelectronics?

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0246180
Author(s):  
Jayeeta Kolay ◽  
Sudipta Bera ◽  
Rupa Mukhopadhyay
Keyword(s):  
Electron Transport ◽  
Structural Characteristics ◽  
Transport Capacity ◽  
Loss Of Function ◽  
Solid State Electron ◽  
Current Sensing ◽  
Surface Integration ◽  
Biomolecular Electronics ◽  
Major Factors ◽  
And Storage

One major obstacle in development of biomolecular electronics is the loss of function of biomolecules upon their surface-integration and storage. Although a number of reports on solid-state electron transport capacity of proteins have been made, no study on whether their functional integrity is preserved upon surface-confinement and storage over a long period of time (few months) has been reported. We have investigated two specific cases—collagen and ferritin proteins, since these proteins exhibit considerable potential as bioelectronic materials as we reported earlier. Since one of the major factors for protein degradation is the proteolytic action of protease, such studies were made under the action of protease, which was either added deliberately or perceived to have entered in the reaction vial from ambient environment. Since no significant change in the structural characteristics of these proteins took place, as observed in the circular dichroism and UV-visible spectrophotometry experiments, and the electron transport capacity was largely retained even upon direct protease exposure as revealed from the current sensing atomic force spectroscopy experiments, we propose that stable films can be formed using the collagen and ferritin proteins. The observed protease-resistance and robust nature of these two proteins support their potential application in bioelectronics.

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