Young Infants' Perception of Illusory Contours in Dynamic Displays

Perception ◽  
1998 ◽  
Vol 27 (3) ◽  
pp. 341-353 ◽  
Author(s):  
Scott P Johnson ◽  
Richard N Aslin
Keyword(s):  
Surface Texture ◽  
Illusory Contours ◽  
The Third ◽  
Young Infants ◽  
Background Texture ◽  
Spatiotemporal Integration

Ninety-six 4-month-old infants were habituated to one of three computer-generated displays depicting two rod parts above and below an occluding box. In the first display, the surfaces and boundaries of the rod and box were specified by dense surface texture. Their depth segregation was specified by accretion and deletion of background texture and motion shear. In the second display, the unity of the rod parts and box, and their depth segregation, were specified only by illusory contours. In the third display, the boundaries of the rod and box were specified by illusory contours, perceptible only via spatiotemporal integration of accretion and deletion of sparse-background-texture elements. Infants appeared to perceive object unity, and segregate the rod and box surfaces, in all three displays, indicating use of illusory contours to perceive bounded surfaces in depth. The results suggest a cognitive contribution to perception of some illusory contours, abilities which seem to be present by at least 4 months of age.

Illusory Contours Do Not Capture Stereopsis—They Just Constrain the Depth Spreading

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 182-182
Author(s):  
J Häkkinen ◽  
I Kojo ◽  
M Liinasuo ◽  
G Nyman
Keyword(s):  
Central Area ◽  
Stereoscopic Depth ◽  
Illusory Figure ◽  
Illusory Contours ◽  
Background Texture ◽  
Background Pattern

If vertical cut-out sectors defining a Kanizsa square are given crossed disparity, the illusory figure appears in depth. Such an illusory figure can pull the background pattern inside the illusory figure to the same depth. It has been assumed that illusory contours are necessary for this phenomenon, which is called stereo capture (Ramachandran, 1986 Perception & Psychophysics39 361 – 373). However, we noticed that the vertical cut-out sectors of the inducing figures (‘pacmen’) are not the only structures that can capture the background texture. The rows of background dots that are enclosed between the disparate vertical cut-out sectors also have unambiguous stereoscopic depth. Thus it might be possible that the disparate rows alone capture the background texture. To investigate our hypothesis we created a stereogram in which the inducing figures were removed. It consisted of a dotted background texture and four areas devoid of dots. The dotless areas corresponded to the areas which were occluded by the original inducing figures. Because of this, the top and bottom rows inside the central area were in crossed disparity. According to our results (a) depth capture also occurred without illusory contours; (b) when illusory contours were not present, the depth of the disparate rows spread more often to other areas. Usually the depth spread first to the central area of the figure and after that horizontally to other areas of the figure. Therefore, we conclude that illusory contours do not capture stereopsis—they just constrain the depth spreading.

THE PERSISTENCE OF POLIOMYELITIS ANTIBODIES AFTER PRIMARY IMMUNIZATION OF YOUNG INFANTS

PEDIATRICS ◽  
1959 ◽  
Vol 23 (3) ◽  
pp. 550-552
Author(s):  
Randolph Batson ◽  
Amos Christie ◽  
Dorothy Turner ◽  
Mary Michal ◽  
Jewell H. Barrick
Keyword(s):  
Natural Infection ◽  
The State ◽  
Primary Immunization ◽  
Protective Response ◽  
The Third ◽  
Young Infants ◽  
Poliomyelitis Vaccine ◽  
Routine Administration ◽  
Antibody Titers ◽  
Antibody Levels

Data has been presented showing that, although 4 months after the third injection of poliomyelitis vaccine, antibody levels were quite high, at 12 months there was a definite and striking decrease in antibody titers. It is suggested that serious consideration be given to the routine administration of a fourth, 1-ml, injection of poliomyelitis vaccine 12 months after the third injection. It would seem advisable to follow this practice unless it can be demonstrated that the state and degree of hypersensitivity, without detectable antibodies, is sufficiently great to result in a protective response when natural infection occurs.

Is Stereoscopic Capture Possible with Three-Dimensionally Slanted or Curved Illusory Surfaces?

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 73-73
Author(s):  
J Häkkinen ◽  
M Liinasuo ◽  
I Kojo ◽  
G Nyman
Keyword(s):  
Three Dimensional ◽  
Complex Surface ◽  
Dimensional Structure ◽  
Curved Surfaces ◽  
Surface Form ◽  
Complex Surfaces ◽  
Illusory Contours ◽  
Three Dimensional Structure ◽  
Background Texture ◽  
Constant Period

The depth of disparate illusory contours affects the perception of background patterns that are enclosed by these contours. If the pattern is repetitive, the depth of the illusory surface is attributed to texture elements even though the texture is in zero disparity. Previous results have suggested that this phenomenon, called stereoscopic capture, is possible only with frontoparallel surfaces (Ramachandran, 1986 Perception & Psychophysics39 361 – 373). We hypothesised that the disruption of stereo capture with three-dimensionally slanted or curved surfaces has been due to the impossibility of consistent rematching of background texture elements. If the texture is designed in such a way that adjacent elements can be rematched to form a surface that is consistent with the three-dimensional structure of the illusory surface, the capture should be possible with complex surfaces. We investigated our hypothesis by showing three-dimensionally slanted and curved surfaces to subjects and changing the pattern of the background texture. According to our results a texture of a constant period can be captured only by a frontoparallel surface; however, if the texture is designed to be consistent with the three-dimensional structure of the complex surface, the texture elements that initially form a frontoparallel surface form a complex surface when they are captured. We conclude that (a) stereoscopic capture is possible with complex three-dimensional surfaces; (b) the possible discrete matches within the background texture determine the possible three-dimensional forms that can be captured and therefore stereoscopic capture should not be characterised only as depth interpolation (Mitchison and McKee, 1987 Vision Research27 285 – 294) between large image elements.

Organization in the Perception of Speech by Young Infants

1992 ◽  
Vol 3 (6) ◽  
pp. 340-345 ◽  
Author(s):  
Peter D. Eimas ◽  
Joanne L. Miller
Keyword(s):  
The Other ◽  
Synthetic Speech ◽  
Formant Transition ◽  
Acoustic Information ◽  
The Third ◽  
Young Infants ◽  
Speech Patterns ◽  
Speech Percept ◽  
Different Sources ◽  
Specialized System

Evidence is presented that 3- and 4-month-old infants are able to integrate two sounds with different sources and locations to form a coherent speech percept. Synthetic speech patterns were presented dichotically so that one ear received the third-formant transition appropriate for the syllable [da] or [ga], and the other car received the base, that is, the remaining acoustic information necessary for syllabic perception. Adults typically perceive these stimuli as a birdlike chirp at the ear receiving the transition and. depending on which transition is presented, as the syllable [da] or [ga] at the ear receiving the base. Infants discriminated the two dichotic patterns. They also discriminated them when the third-formant transitions were attenuated to the extent that infant listeners could not discriminate them when they were presented in isolation. The results support the contention that the infants integrated the two disparate sources of acoustic information into a coherent percept that is presumably phonetic in nature, and they are also consistent with the view that this organization arises from a specialized system for the perception of speech.

Infant Response to Impending Optical Collision

Perception ◽  
1980 ◽  
Vol 9 (5) ◽  
pp. 549-554 ◽  
Author(s):  
Jane Dunkeld ◽  
Tom G R Bower
Keyword(s):  
The Third ◽  
Similar Transformation ◽  
Young Infants ◽  
Third Dimension

Young infants withdraw their heads when shown a display simulating a rectangle rotating towards their faces. The head withdrawal is specific to that transformation and is not elicited by a similar transformation which does not specify approach. This is possible evidence of an unlearned ability to pick up information about change of position in the third dimension.

Progress report on 21-cm observations at low latitude between longitudes (l 11) 0° and 66°

1967 ◽  
Vol 31 ◽  
pp. 177-179
Author(s):  
W. W. Shane
Keyword(s):  
Preliminary Report ◽  
Progress Report ◽  
Galactic Centre ◽  
Low Latitude ◽  
The Third ◽  
Introductory Lecture ◽  
Centre Region

In the course of several 21-cm observing programmes being carried out by the Leiden Observatory with the 25-meter telescope at Dwingeloo, a fairly complete, though inhomogeneous, survey of the regionl11= 0° to 66° at low galactic latitudes is becoming available. The essential data on this survey are presented in Table 1. Oort (1967) has given a preliminary report on the first and third investigations. The third is discussed briefly by Kerr in his introductory lecture on the galactic centre region (Paper 42). Burton (1966) has published provisional results of the fifth investigation, and I have discussed the sixth in Paper 19. All of the observations listed in the table have been completed, but we plan to extend investigation 3 to a much finer grid of positions.

The orbit of Pluto over a long interval of time

1966 ◽  
Vol 25 ◽  
pp. 227-229 ◽  
Author(s):  
D. Brouwer
Keyword(s):  
Periodic Orbit ◽  
Numerical Integration ◽  
Restricted Problem ◽  
Three Dimensional ◽  
The Third ◽  
Circular Restricted Problem ◽  
Resonance Relation

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.

Monte Carlo Algorithms for Moments of Transition Arrays

1988 ◽  
Vol 102 ◽  
pp. 79-81
Author(s):  
A. Goldberg ◽  
S.D. Bloom
Keyword(s):  
Monte Carlo ◽  
State Vector ◽  
Basis Vector ◽  
Collective State ◽  
Dispersion Characteristics ◽  
Dipole Strength ◽  
The Third ◽  
Monte Carlo Algorithms ◽  
Third Moment ◽  
Very High

AbstractClosed expressions for the first, second, and (in some cases) the third moment of atomic transition arrays now exist. Recently a method has been developed for getting to very high moments (up to the 12th and beyond) in cases where a “collective” state-vector (i.e. a state-vector containing the entire electric dipole strength) can be created from each eigenstate in the parent configuration. Both of these approaches give exact results. Herein we describe astatistical(or Monte Carlo) approach which requires onlyonerepresentative state-vector |RV> for the entire parent manifold to get estimates of transition moments of high order. The representation is achieved through the random amplitudes associated with each basis vector making up |RV>. This also gives rise to the dispersion characterizing the method, which has been applied to a system (in the M shell) with≈250,000 lines where we have calculated up to the 5th moment. It turns out that the dispersion in the moments decreases with the size of the manifold, making its application to very big systems statistically advantageous. A discussion of the method and these dispersion characteristics will be presented.

Probe size and 5th-order aberration

1987 ◽  
Vol 45 ◽  
pp. 134-135 ◽  
Author(s):  
Zhifeng Shao
Keyword(s):  
Electron Probe ◽  
Spherical Aberration ◽  
Wave Length ◽  
Cylindrical Symmetry ◽  
Electron Wave ◽  
Third Order ◽  
The Third ◽  
Probe Radius ◽  
Small Probe ◽  
Probe Size

A small electron probe has many applications in many fields and in the case of the STEM, the probe size essentially determines the ultimate resolution. However, there are many difficulties in obtaining a very small probe.Spherical aberration is one of them and all existing probe forming systems have non-zero spherical aberration. The ultimate probe radius is given byδ = 0.43Csl/4ƛ3/4where ƛ is the electron wave length and it is apparent that δ decreases only slowly with decreasing Cs. Scherzer pointed out that the third order aberration coefficient always has the same sign regardless of the field distribution, provided only that the fields have cylindrical symmetry, are independent of time and no space charge is present. To overcome this problem, he proposed a corrector consisting of octupoles and quadrupoles.

The effects of Cyclosporin-A (CYA) on the Ultrastructure of Gingival Mast Cells (GMC) in Behcet's disease (BD)

1990 ◽  
Vol 48 (3) ◽  
pp. 358-359
Author(s):  
Oktay Arda ◽  
Ulkü Noyan ◽  
Selgçk Yilmaz ◽  
Mustafa Taşyürekli ◽  
İsmail Seçkin ◽  
...  
Keyword(s):  
Unknown Etiology ◽  
Control Group ◽  
Target Cells ◽  
Gingival Hyperplasia ◽  
Cellular Activity ◽  
Direct Relation ◽  
Immune Disease ◽  
Genital Ulceration ◽  
Functional Changes ◽  
The Third

Turkish dermatologist, H. Beheet described the disease as recurrent triad of iritis, oral aphthous lesions and genital ulceration. Auto immune disease is the recent focus on the unknown etiology which is still being discussed. Among the other immunosupressive drugs, CyA included in it's treatment newly. One of the important side effects of this drug is gingival hyperplasia which has a direct relation with the presence of teeth and periodontal tissue. We are interested in the ultrastructure of immunocompetent target cells that were affected by CyA in BD.Three groups arranged in each having 5 patients with BD. Control group was the first and didn’t have CyA treatment. Patients who had CyA, but didn’t show gingival hyperplasia assembled the second group. The ones displaying gingival hyperplasia following CyA therapy formed the third group. GMC of control group and their granules are shown in FIG. 1,2,3. GMC of the second group presented initiation of supplementary cellular activity and possible maturing functional changes with the signs of increased number of mitochondria and accumulation of numerous dense cored granules next to few normal ones, FIG. 4,5,6.

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