Viewpoint Dependence in the Recognition of Non-Elongated Familiar Objects: Testing the Effects of Symmetry, Front-Back Axis, and Familiarity

Perception ◽  
10.1068/p6161 ◽  
2009 ◽  
Vol 38 (4) ◽  
pp. 533-551 ◽  
Author(s):  
Ryosuke Niimi ◽  
Kazuhiko Yokosawa
Keyword(s):  
Object Recognition ◽  
Visual Recognition ◽  
Three Dimensional ◽  
Symmetry Plane ◽  
Familiar Object ◽  
Viewpoint Dependence ◽  
Familiar Objects

Visual recognition of three-dimensional (3-D) objects is relatively impaired for some particular views, called accidental views. For most familiar objects, the front and top views are considered to be accidental views. Previous studies have shown that foreshortening of the axes of elongation of objects in these views impairs recognition, but the influence of other possible factors is largely unknown. Using familiar objects without a salient axis of elongation, we found that a foreshortened symmetry plane of the object and low familiarity of the viewpoint accounted for the relatively worse recognition for front views and top views, independently of the effect of a foreshortened axis of elongation. We found no evidence that foreshortened front–back axes impaired recognition in front views. These results suggest that the viewpoint dependence of familiar object recognition is not a unitary phenomenon. The possible role of symmetry (either 2-D or 3-D) in familiar object recognition is also discussed.

scholarly journals EIGENVALUE SPECTRUM FOR A SINGLE PARTICLE IN A SPHEROIDAL CAVITY: A SEMICLASSICAL APPROACH

2002 ◽  
Vol 11 (04) ◽  
pp. 303-320
Author(s):  
SHAM S. MALIK ◽  
A. K. JAIN ◽  
S. R. JAIN
Keyword(s):  
Trace Formula ◽  
Three Dimensional ◽  
Symmetry Plane ◽  
Decimal Place ◽  
Partial Sums ◽  
Quantum Mechanical ◽  
Eigenvalue Spectrum ◽  
Angular Momentum Projection ◽  
Spheroidal Cavity

Following the semiclassical formalism of Strutinsky et al.,11 we have obtained the complete eigenvalue spectrum for a particle enclosed in an infinitely high spheroidal cavity. Our spheroidal trace formula also reproduces the results of a spherical billiard in the limit η → 1.0. Inclusion of repetition of each family of the orbits with reference to the largest one significantly improves the eigenvalues of the sphere and an exact comparison with the quantum mechanical results is observed up to the second decimal place for kR0 ≥ 7. The contributions of the equatorial, planar (in the axis of symmetry plane) and non-planar (three-dimensional) orbits are obtained from the same trace formula by using the appropriate conditions. The resulting eigenvalues compare very well with the quantum mechanical eigenvalues at normal deformation. It is interesting that the partial sum of equatorial orbits leads to eigenvalues with maximum angular momentum projection, while the summing of planar orbits leads to eigenvalues with Lz = 0 except for L = 1. The remaining quantum mechanical eigenvalues are observed to arise from the three-dimensional (3D) orbits. Very few spurious eigenvalues arise in these partial sums. This result establishes the important role of 3D orbits even at normal deformations.

The Role of Edges in Object Recognition by Pigeons

Perception ◽  
10.1068/p5427 ◽  
2005 ◽  
Vol 34 (11) ◽  
pp. 1353-1374 ◽  
Author(s):  
Jessie J Peissig ◽  
Michael E Young ◽  
Edward A Wasserman ◽  
Irving Biederman
Keyword(s):  
Object Recognition ◽  
Visual Recognition ◽  
Line Drawing ◽  
Human Recognition ◽  
Single View ◽  
Line Drawings ◽  
Consistent Condition ◽  
Depth Discontinuities ◽  
Planar Rotations

In three experiments, we explored how pigeons use edges, corresponding to orientation and depth discontinuities, in visual recognition tasks. In experiment 1, we compared the pigeon's ability to recognize line drawings of four different geons when trained with shaded images. The birds were trained with either a single view or five different views of each object. Because the five training views had markedly different appearances and locations of shaded surfaces, reflectance edges, etc, the pigeons might have been expected to rely more on the orientation and depth discontinuities that were preserved over rotation and in the line drawings. In neither condition, however, was there any transfer from the rendered images to the outline drawings. In experiment 2, some pigeons were trained with line drawings and shaded images of the same objects associated with the same response (consistent condition), whereas other pigeons were trained with a line drawing and a shaded image of two different objects associated with the same response (inconsistent condition). If the pigeons perceived any correspondence between the stimulus types, then birds in the consistent condition should have learned the discrimination more quickly than birds in the inconsistent condition. But, there was no difference in performance between birds in the consistent and inconsistent conditions. In experiment 3, we explored pigeons' processing of edges by comparing their discrimination of shaded images or line drawings of four objects. Once trained, the pigeons were tested with planar rotations of those objects. The pigeons exhibited different patterns of generalization depending on whether they were trained with line drawings or shaded images. The results of these three experiments suggest that pigeons may place greater importance on surface features indicating materials, such as food or water. Such substances do not have definite boundaries—cued by edges—which are thought to be central to human recognition.

The Role of Three-Dimensional Imaging in Evaluation of the Sinonasal Mass

1996 ◽  
Vol 34 (1) ◽  
pp. 27
Author(s):  
Sue Yon Shim ◽  
Ki Joon Sung ◽  
Young Ju Kim ◽  
In Soo Hong ◽  
Myung Soon Kim ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Three Dimensional Imaging ◽  
Sinonasal Mass

Homogenization and Mass Identity vs. Individual Identity. An Analysis in the Light of the Theory of “The Three Dimensional Spiral of Sense

2016 ◽  
Vol 2 (2) ◽  
pp. 40
Author(s):  
Miriam Aparicio
Keyword(s):  
Three Dimensional ◽  
Individual Identity ◽  
Cognitive Effects ◽  
The Media

This study tests some hypotheses included in the psycho-social-communicational paradigm, which emphasizes the cognitive effects of the media and the role of the psychosocial subject as the recipient

Featural and Configural Processing of Faces and Houses in Matched Dyslexic and Typical Readers

2020 ◽  
Author(s):  
Bahareh Jozranjbar ◽  
Arni Kristjansson ◽  
Heida Maria Sigurdardottir
Keyword(s):  
Object Recognition ◽  
Visual Processing ◽  
Reading Ability ◽  
Visual Recognition ◽  
Reading Deficits ◽  
Domain Specific ◽  
Configural Information ◽  
Lower House ◽  
Single Process ◽  
Processing Mechanisms

While dyslexia is typically described as a phonological deficit, recent evidence suggests that ventral stream regions, important for visual categorization and object recognition, are hypoactive in dyslexic readers who might accordingly show visual recognition deficits. By manipulating featural and configural information of faces and houses, we investigated whether dyslexic readers are disadvantaged at recognizing certain object classes or utilizing particular visual processing mechanisms. Dyslexic readers found it harder to recognize objects (houses), suggesting that visual problems in dyslexia are not completely domain-specific. Mean accuracy for faces was equivalent in the two groups, compatible with domain-specificity in face processing. While face recognition abilities correlated with reading ability, lower house accuracy was nonetheless related to reading difficulties even when accuracy for faces was kept constant, suggesting a specific relationship between visual word recognition and the recognition of non-face objects. Representational similarity analyses (RSA) revealed that featural and configural processes were clearly separable in typical readers, while dyslexic readers appeared to rely on a single process. This occurred for both faces and houses and was not restricted to particular visual categories. We speculate that reading deficits in some dyslexic readers reflect their reliance on a single process for object recognition.

Dysregulation of HOX as a Potential Therapeutic Target in Breast Cancer

2020 ◽  
Vol 27 ◽  
Author(s):  
Ji-Yeon Lee ◽  
Myoung Hee Kim
Keyword(s):  
Breast Cancer ◽  
Hox Genes ◽  
Therapeutic Potential ◽  
Expression Patterns ◽  
Genome Structure ◽  
Control Cell ◽  
Three Dimensional ◽  
Cellular Processes ◽  
Hox Protein

: HOX genes belong to the highly conserved homeobox superfamily, responsible for the regulation of various cellular processes that control cell homeostasis, from embryogenesis to carcinogenesis. The abnormal expression of HOX genes is observed in various cancers, including breast cancer; they act as oncogenes or as suppressors of cancer, according to context. In this review, we analyze HOX gene expression patterns in breast cancer and examine their relationship, based on the three-dimensional genome structure of the HOX locus. The presence of non-coding RNAs, embedded within the HOX cluster, and the role of these molecules in breast cancer have been reviewed. We further evaluate the characteristic activity of HOX protein in breast cancer and its therapeutic potential.

Central ossifying fibroma of mandible

2020 ◽  
Vol 13 (12) ◽  
pp. e239286
Author(s):  
Kumar Nilesh ◽  
Prashant Punde ◽  
Nitin Shivajirao Patil ◽  
Amol Gautam
Keyword(s):  
Fibrous Tissue ◽  
Three Dimensional ◽  
Facial Asymmetry ◽  
Ossifying Fibroma ◽  
Mandible Reconstruction ◽  
Three Dimensional Printing ◽  
Osseous Lesion ◽  
Large Size ◽  
Dimensional Printing

Ossifying fibroma (OF) is a rare, benign, fibro-osseous lesion of the jawbone characterised by replacement of the normal bone with fibrous tissue. The fibrous tissue shows varying amount of calcified structures resembling bone and/or cementum. The central variant of OF is rare, and shows predilection for mandible among the jawbone. Although it is classified as fibro-osseous lesion, it clinically behaves as a benign tumour and can grow to large size, causing bony swelling and facial asymmetry. This paper reports a case of large central OF of mandible in a 40-year-old male patient. The lesion was treated by segmental resection of mandible. Reconstruction of the surgical defect was done using avascular fibula bone graft. Role of three-dimensional printing of jaw and its benefits in surgical planning and reconstruction are also highlighted.

scholarly journals Charge algebra in Al(A)dSn spacetimes

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Adrien Fiorucci ◽  
Romain Ruzziconi
Keyword(s):  
Boundary Conditions ◽  
Dirichlet Boundary ◽  
Three Dimensional ◽  
Dirichlet Boundary Conditions ◽  
Boundary Structure ◽  
Asymptotic Symmetry ◽  
Renormalization Procedure ◽  
Field Dependent ◽  
Odd Dimensions

Abstract The gravitational charge algebra of generic asymptotically locally (A)dS spacetimes is derived in n dimensions. The analysis is performed in the Starobinsky/Fefferman-Graham gauge, without assuming any further boundary condition than the minimal falloffs for conformal compactification. In particular, the boundary structure is allowed to fluctuate and plays the role of source yielding some symplectic flux at the boundary. Using the holographic renormalization procedure, the divergences are removed from the symplectic structure, which leads to finite expressions. The charges associated with boundary diffeomorphisms are generically non-vanishing, non-integrable and not conserved, while those associated with boundary Weyl rescalings are non-vanishing only in odd dimensions due to the presence of Weyl anomalies in the dual theory. The charge algebra exhibits a field-dependent 2-cocycle in odd dimensions. When the general framework is restricted to three-dimensional asymptotically AdS spacetimes with Dirichlet boundary conditions, the 2-cocycle reduces to the Brown-Henneaux central extension. The analysis is also specified to leaky boundary conditions in asymptotically locally (A)dS spacetimes that lead to the Λ-BMS asymptotic symmetry group. In the flat limit, the latter contracts into the BMS group in n dimensions.

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