The Role of Motion in Infants' Perception of Solid Shape

Perception ◽  
1983 ◽  
Vol 12 (6) ◽  
pp. 707-717 ◽  
Author(s):  
Cynthia Owsley
Keyword(s):  
Three Dimensional ◽  
Depth Information ◽  
Visual Depth ◽  
Depth Cues ◽  
Kinetic Depth ◽  
Dimensional Shape ◽  
Three Dimensional Shape ◽  
Visual Habituation ◽  
Binocular Depth

Previous research has shown that infants as young as the first few months of life perceive several aspects of the three-dimensional environment. Yet we know relatively little about the visual depth information which serves as a basis for their spatial capacities. A study is reported in which a visual habituation procedure was used to examine what types of optical depth information four-month-old infants find useful in visually perceiving solid (three-dimensional) shape. Results imply that in the absence of binocular depth cues four-month-olds rely on kinetic depth information to perceive solid shape.

Self‐Assembly of a β‐Peptide Foldamer: The Role of the Surfactant in Three‐Dimensional Shape Selection

ChemPlusChem ◽  
2019 ◽  
Vol 84 (5) ◽  
pp. 481-487 ◽  
Author(s):  
Jintaek Gong ◽  
Taedaehyeong Eom ◽  
Wonchul Lee ◽  
Arup Roy ◽  
Sunbum Kwon ◽  
...  
Keyword(s):  
Self Assembly ◽  
Three Dimensional ◽  
Shape Selection ◽  
Dimensional Shape ◽  
Three Dimensional Shape

scholarly journals Stimulus Dependence of Disparity Coding in Primate Visual Area V4

2005 ◽  
Vol 93 (1) ◽  
pp. 620-626 ◽  
Author(s):  
Jay Hegdé ◽  
David C. Van Essen
Keyword(s):  
Binocular Disparity ◽  
Three Dimensional ◽  
Visual Area ◽  
Tuning Curves ◽  
Depth Cues ◽  
Area V4 ◽  
Random Dot Stereograms ◽  
Dimensional Shape ◽  
Visual Area V4 ◽  
Three Dimensional Shape

Disparity tuning in visual cortex has been shown using a variety of stimulus types that contain stereoscopic depth cues. It is not known whether different stimuli yield similar disparity tuning curves. We studied whether cells in visual area V4 of the macaque show similar disparity tuning profiles when the same set of disparity values were tested using bars or dynamic random dot stereograms, which are among the most commonly used stimuli for this purpose. In a majority of V4 cells (61%), the shape of the disparity tuning profile differed significantly for the two stimulus types. The two sets of stimuli yielded statistically indistinguishable disparity tuning profiles for only a small minority (6%) of V4 cells. These results indicate that disparity tuning in V4 is stimulus-dependent. Given the fact that bar stimuli contain two-dimensional (2-D) shape cues, and the random dot stereograms do not, our results also indicate that V4 cells represent 2-D shape and binocular disparity in an interdependent fashion, revealing an unexpected complexity in the analysis of depth and three-dimensional shape.

scholarly journals Disruptive coloration and binocular disparity: breaking camouflage

2019 ◽  
Vol 286 (1896) ◽  
pp. 20182045 ◽  
Author(s):  
Wendy J. Adams ◽  
Erich W. Graf ◽  
Matt Anderson
Keyword(s):  
Critical Role ◽  
Three Dimensional ◽  
Stereoscopic Vision ◽  
Dimensional Structure ◽  
Depth Information ◽  
Edge Enhancement ◽  
Depth Cues ◽  
Disruptive Coloration ◽  
True Shape ◽  
Binocular Depth

Many species employ camouflage to disguise their true shape and avoid detection or recognition. Disruptive coloration is a form of camouflage in which high-contrast patterns obscure internal features or break up an animal's outline. In particular, edge enhancement creates illusory, or ‘fake’ depth edges within the animal's body. Disruptive coloration often co-occurs with background matching, and together, these strategies make it difficult for an observer to visually segment an animal from its background. However, stereoscopic vision could provide a critical advantage in the arms race between perception and camouflage: the depth information provided by binocular disparities reveals the true three-dimensional layout of a scene, and might, therefore, help an observer to overcome the effects of disruptive coloration. Human observers located snake targets embedded in leafy backgrounds. We analysed performance (response time) as a function of edge enhancement, illumination conditions and the availability of binocular depth cues. We confirm that edge enhancement contributes to effective camouflage: observers were slower to find snakes whose patterning contains ‘fake’ depth edges. Importantly, however, this effect disappeared when binocular depth cues were available. Illumination also affected detection: under directional illumination, where both the leaves and snake produced strong cast shadows, snake targets were localized more quickly than in scenes rendered under ambient illumination. In summary, we show that illusory depth edges, created via disruptive coloration, help to conceal targets from human observers. However, cast shadows and binocular depth information improve detection by providing information about the true three-dimensional structure of a scene. Importantly, the strong interaction between disparity and edge enhancement suggests that stereoscopic vision has a critical role in breaking camouflage, enabling the observer to overcome the disruptive effects of edge enhancement.

scholarly journals Binocular depth processing in the ventral visual pathway

2016 ◽  
Vol 371 (1697) ◽  
pp. 20150259 ◽  
Author(s):  
Bram-Ernst Verhoef ◽  
Rufin Vogels ◽  
Peter Janssen
Keyword(s):  
Three Dimensional ◽  
Visual Pathway ◽  
Object Processing ◽  
Depth Processing ◽  
Ventral Visual Pathway ◽  
Ventral Pathway ◽  
Dimensional Shape ◽  
Three Dimensional Shape ◽  
The Brain ◽  
Binocular Depth

One of the most powerful forms of depth perception capitalizes on the small relative displacements, or binocular disparities, in the images projected onto each eye. The brain employs these disparities to facilitate various computations, including sensori-motor transformations (reaching, grasping), scene segmentation and object recognition. In accordance with these different functions, disparity activates a large number of regions in the brain of both humans and monkeys. Here, we review how disparity processing evolves along different regions of the ventral visual pathway of macaques, emphasizing research based on both correlational and causal techniques. We will discuss the progression in the ventral pathway from a basic absolute disparity representation to a more complex three-dimensional shape code. We will show that, in the course of this evolution, the underlying neuronal activity becomes progressively more bound to the global perceptual experience. We argue that these observations most probably extend beyond disparity processing per se , and pertain to object processing in the ventral pathway in general. We conclude by posing some important unresolved questions whose answers may significantly advance the field, and broaden its scope. This article is part of the themed issue ‘Vision in our three-dimensional world’.

scholarly journals Cellular geometry controls the efficiency of motile sperm aggregates

2018 ◽  
Author(s):  
D. J. G. Pearce ◽  
L. Hoogerbrugge ◽  
K. A. Hook ◽  
H. S. Fisher ◽  
L. Giomi
Keyword(s):  
Three Dimensional ◽  
Cell Binding ◽  
Head Shape ◽  
Random Walker ◽  
Muroid Rodents ◽  
Dimensional Shape ◽  
Biochemical Mechanisms ◽  
The Stability ◽  
Three Dimensional Shape

Teams of cooperating sperm have been found across several vertebrate and invertebrate species, ranging from sperm pairs to massive aggregates containing hundreds of cells. Although the biochemical mechanisms involved in sperm-sperm adhesion are unclear, aggregation can enhance the motility of the cells. Here, we report a thorough computational investigation on the role of cellular geometry in the performance of sperm aggregates. The sperm head is modeled as a persistent random walker characterized by a non-trivial three-dimensional shape and equipped with an adhesive region where cell-cell binding occurs. By considering both a simple parametric head shape and a computer reconstruction of a real head shape based on morphometric data, we demonstrate that the geometry of the head and the structure of the adhesive region crucially affect both the stability and motility of the aggregates. Our analysis further suggests that the apical hook, commonly found in the sperm of most muroid rodents, might serve to shield portions of the adhesive region and promote efficient alignment of the velocities of the interacting cells.

scholarly journals Cellular geometry controls the efficiency of motile sperm aggregates

2018 ◽  
Vol 15 (148) ◽  
pp. 20180702 ◽  
Author(s):  
D. J. G. Pearce ◽  
L. A. Hoogerbrugge ◽  
K. A. Hook ◽  
H. S. Fisher ◽  
L. Giomi
Keyword(s):  
Molecular Mechanisms ◽  
Three Dimensional ◽  
Cell Binding ◽  
Head Shape ◽  
Random Walker ◽  
Muroid Rodents ◽  
Dimensional Shape ◽  
The Stability ◽  
Three Dimensional Shape

Sperm that swim collectively to the fertilization site have been observed across several vertebrate and invertebrate species, with groups ranging in size from sperm pairs to massive aggregates containing hundreds of cells. Although the molecular mechanisms that regulate sperm–sperm adhesion are still unclear, aggregation can enhance sperm motility and thus offer a fertilization advantage. Here, we report a thorough computational investigation on the role of cellular geometry in the performance of sperm aggregates. The sperm head is modelled as a persistent random walker characterized by a non-trivial three-dimensional shape and equipped with an adhesive region where cell–cell binding occurs. By considering both, a simple parametric head shape and a computer reconstruction of a real head shape based on morphometric data, we demonstrate that the geometry of the head and the structure of the adhesive region crucially affects both the stability and motility of the aggregates. Our analysis further suggests that the apical hook commonly found in the sperm of muroid rodents might serve to shield portions of the adhesive region and promote efficient alignment of the velocities of the interacting cells.

scholarly journals Three-dimensional shape perception from chromatic orientation flows

2006 ◽  
Vol 23 (3-4) ◽  
pp. 323-330 ◽  
Author(s):  
QASIM ZAIDI ◽  
ANDREA LI
Keyword(s):  
Three Dimensional ◽  
Shape Perception ◽  
Retinal Images ◽  
Accurate Perception ◽  
Dimensional Shape ◽  
Three Dimensional Shape

The role of chromatic information in 3-D shape perception is controversial. We resolve this controversy by showing that chromatic orientation flows are sufficient for accurate perception of 3-D shape. Chromatic flows required less cone contrast to convey shape than did achromatic flows, thus ruling out luminance artifacts as a problem. Luminance artifacts were also ruled out by a protanope's inability to see 3-D shape from chromatic flows. Since chromatic orientation flows can only be extracted from retinal images by neurons that are responsive to color modulations and selective for orientation, the psychophysical results also resolve the controversy over the existence of such neurons. In addition, we show that identification of 3-D shapes from chromatic flows can be masked by luminance modulations, indicating that it is subserved by orientation-tuned neurons sensitive to both chromatic and luminance modulations.

Four Dimensions of Diamond T: Combination Trade Marks of Colours And Shapes

2006 ◽  
Vol 37 (4) ◽  
pp. 583
Author(s):  
Michael McGowan
Keyword(s):  
Three Dimensional ◽  
Trade Mark ◽  
Fourth Dimension ◽  
Trade Marks ◽  
Four Dimensions ◽  
Trade Mark Law ◽  
Dimensional Shape ◽  
Three Dimensional Shape

This article examines the relatively new fields of colour and shape trade marks. It was initially feared by some academics that the new marks would encroach on the realms of patent and copyright.  However, the traditional requirements of trade mark law, such as functionality and descriptiveness, have meant that trade marks in colour and shape are extremely hard to acquire if they do not have factual distinctiveness. As colour and shape trade marks have no special restrictions, it is proposed that the combination trade mark theory and analysis from the Diamond T case should be used as a way to make them more accessible. The combination analysis can be easily applied because every product has a three dimensional shape and a fourth dimension of colour.

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