scholarly journals A quantitative analysis of illusion magnitude predicted by several averaging theories of the Müller-Lyer illusion

1993 ◽  
Vol 53 (5) ◽  
pp. 498-504 ◽  
Author(s):  
Patricia R. Delucia
Keyword(s):  
Quantitative Analysis ◽  
Illusion Magnitude ◽  
Lyer Illusion

Decrement and the Illusions of the Mueller-Lyer Figure

1994 ◽  
Vol 79 (2) ◽  
pp. 707-717 ◽  
Author(s):  
Clare Porac
Keyword(s):  
Perceptual Learning ◽  
Illusion Magnitude ◽  
Group Level ◽  
Illusion Decrement ◽  
Significant Time ◽  
Lyer Illusion ◽  
Significant Decrement ◽  
Level Data

Decrement, a time-related decrease in the magnitude of the Mueller-Lyer illusion, was measured separately for the wings-out and the wings-in variants of the Mueller-Lyer figure. There were significant reductions of wings-out illusion magnitude during the decrement period. Observers viewing the wings-in segment showed a non-significant decrement pattern. Analyses of individual decrement patterns showed that illusion magnitude did not decrease for a number of observers even when there were significant time-related trends at the group level. Data for 80 observers imply that the mechanisms of perceptual learning proposed by previous models of Mueller-Lyer illusion decrement are not sufficient explanations of the decrement process.

Iris Pigmentation and Visual-Geometric Illusions

Perception ◽  
1978 ◽  
Vol 7 (4) ◽  
pp. 473-477 ◽  
Author(s):  
Stanley Coren ◽  
Clare Porac
Keyword(s):  
Retinal Image ◽  
Scattered Light ◽  
Illusion Magnitude ◽  
Ebbinghaus Illusion ◽  
Image Degradation ◽  
Lyer Illusion ◽  
Iris Pigmentation ◽  
Line Elements

Blur or degrading of the retinal image has been shown to be a factor in the formation of visual-geometric illusions where intersecting line elements are present. Light irises allow more scattered light within the eye, which results in more image degradation than found in dark-eyed subjects. Measurements on 755 observers show that illusion magnitude varies as a function of iris pigmentation for a configuration with intersecting line elements (Müller — Lyer illusion), but not for a configuration devoid of such features (Ebbinghaus illusion).

Decrement of the Brentano Müller-Lyer Illusion as a Function of Inspection Time

Perception ◽  
1998 ◽  
Vol 27 (2) ◽  
pp. 183-192 ◽  
Author(s):  
John Predebon
Keyword(s):  
Visual Inspection ◽  
Illusion Magnitude ◽  
Inspection Time ◽  
Inspection Period ◽  
Illusion Figure ◽  
Illusion Decrement ◽  
Lyer Illusion ◽  
Time Period ◽  
Post Test ◽  
Time Periods

Two experiments are reported in which the decline or decrement in the magnitude of the Brentano Müller-Lyer illusion was measured. Observers made a pre-test judgment and, after a variable intervening time period, a post-test judgment of illusion magnitude. In experiment 1, the intervening time periods were 1, 2, and 3 min during which time the independent groups of observers allocated to each of the three time periods either systematically scanned the Brentano figure (inspection conditions) or waited until the intervening period had elapsed (no-inspection conditions). Experiment 2, which included an additional 5 min intervening time period, evaluated a response-bias explanation for the results of the inspection conditions of experiment 1. Taken together, the findings of the two experiments indicate that sheer inspection of the Brentano figure produces illusion decrement. However, illusion decrement was independent of the duration of the inspection period, with equivalent amounts of decrement occurring across the range of viewing times examined in the two experiments. The pattern of these results suggests that theories of Müller-Lyer decrement must incorporate a factor attributable to, or correlated with, inspection time, whose effect in reducing illusion magnitude is confined mainly to the first 1 or 2 min of active visual inspection of the Brentano illusion figure.

The Role of the Angle Components in the Wings-in and Wings-out Forms of the Müller-Lyer Illusion

Perception ◽  
1996 ◽  
Vol 25 (7) ◽  
pp. 773-781 ◽  
Author(s):  
John Predebon
Keyword(s):  
Illusion Magnitude ◽  
Paired Comparisons ◽  
Lyer Illusion ◽  
Psychological Continuum ◽  
Method Of Paired Comparisons ◽  
Good Agreement

The effect of selective amputations of the angle components in the wings-in (underestimated) and wings-out (overestimated) forms of the Müller-Lyer illusion was examined in two experiments. The stimulus figures consisted of one, two, or four angles. In experiment 1 the method of paired comparisons was used to scale the figures on the psychological continuum of length, and in experiment 2 the method of reproduction was used to obtain quantitative measures of illusion magnitude. There was good agreement between the scaling and the length-reproduction measures of the illusion. The illusory effects in all figures were significant, and the extent of the underestimation and overestimation of the wings-in and wings-out figures, respectively, increased as the number of angles increased. In general, selective amputation of the angle components produced similar patterns of illusory effects in the wings-in and wings-out figures. These findings are discussed with reference to the issue of whether the two forms of the conventional (ie four-angle) Müller-Lyer illusion are similar or distinct illusion types.

An Improved Quantitative Image Analyser

1977 ◽  
Vol 35 ◽  
pp. 226-227
Author(s):  
J.P. Fallon ◽  
P.J. Gregory ◽  
C.J. Taylor
Keyword(s):  
Feature Extraction ◽  
Quantitative Analysis ◽  
Frequency Content ◽  
General Sense ◽  
Physical Measurements ◽  
Quantitative Image ◽  
Image Analyser ◽  
Automatic Methods ◽  
Quantitative Results

Quantitative image analysis systems have been used for several years in research and quality control applications in various fields including metallurgy and medicine. The technique has been applied as an extension of subjective microscopy to problems requiring quantitative results and which are amenable to automatic methods of interpretation.Feature extraction. In the most general sense, a feature can be defined as a portion of the image which differs in some consistent way from the background. A feature may be characterized by the density difference between itself and the background, by an edge gradient, or by the spatial frequency content (texture) within its boundaries. The task of feature extraction includes recognition of features and encoding of the associated information for quantitative analysis.Quantitative Analysis. Quantitative analysis is the determination of one or more physical measurements of each feature. These measurements may be straightforward ones such as area, length, or perimeter, or more complex stereological measurements such as convex perimeter or Feret's diameter.

Quantification of Silica Uptake by Alveolar Macrophages - An Emperical Scanning Electron Microprobe Method

1982 ◽  
Vol 40 ◽  
pp. 332-333
Author(s):  
V. V. Damiano ◽  
R. P. Daniele ◽  
H. T. Tucker ◽  
J. H. Dauber
Keyword(s):  
Quantitative Analysis ◽  
Alveolar Macrophages ◽  
Bulk Sample ◽  
Silica Particles ◽  
Empirical Method ◽  
Phagocytic Cells ◽  
Calibration Standards ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Scanning Electron

An important example of intracellular particles is encountered in silicosis where alveolar macrophages ingest inspired silica particles. The quantitation of the silica uptake by these cells may be a potentially useful method for monitoring silica exposure. Accurate quantitative analysis of ingested silica by phagocytic cells is difficult because the particles are frequently small, irregularly shaped and cannot be visualized within the cells. Semiquantitative methods which make use of particles of known size, shape and composition as calibration standards may be the most direct and simplest approach to undertake. The present paper describes an empirical method in which glass microspheres were used as a model to show how the ratio of the silicon Kα peak X-ray intensity from the microspheres to that of a bulk sample of the same composition correlated to the mass of the microsphere contained within the cell. Irregular shaped silica particles were also analyzed and a calibration curve was generated from these data.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

An example of spectrum imaging used for comparison of EELS quantitative analysis techniques on Al-Li

1991 ◽  
Vol 49 ◽  
pp. 726-727
Author(s):  
John A. Hunt
Keyword(s):  
Quantitative Analysis ◽  
Large Data ◽  
Difference Spectrum ◽  
Large Data Sets ◽  
Foil Thickness ◽  
Data Sets ◽  
Analysis Techniques ◽  
Spectrum Imaging ◽  
Normal Spectrum ◽  
Electron Energy Loss

Spectrum-imaging is a useful technique for comparing different processing methods on very large data sets which are identical for each method. This paper is concerned with comparing methods of electron energy-loss spectroscopy (EELS) quantitative analysis on the Al-Li system. The spectrum-image analyzed here was obtained from an Al-10at%Li foil aged to produce δ' precipitates that can span the foil thickness. Two 1024 channel EELS spectra offset in energy by 1 eV were recorded and stored at each pixel in the 80x80 spectrum-image (25 Mbytes). An energy range of 39-89eV (20 channels/eV) are represented. During processing the spectra are either subtracted to create an artifact corrected difference spectrum, or the energy offset is numerically removed and the spectra are added to create a normal spectrum. The spectrum-images are processed into 2D floating-point images using methods and software described in [1].

The use of a Bent Grid to Improve the take-Off Angle for Electron Probe Analysis

1976 ◽  
Vol 34 ◽  
pp. 360-361
Author(s):  
Delbert E. Philpott ◽  
David Leaffer
Keyword(s):  
Quantitative Analysis ◽  
Tilt Angle ◽  
Count Rate ◽  
Electron Probe ◽  
Open Area ◽  
Electron Probe Analysis ◽  
Background Ratio ◽  
Probe Analysis

There are certain advantages for electron probe analysis if the sample can be tilted directly towards the detector. The count rate is higher, it optimizes the geometry since only one angle need be taken into account for quantitative analysis and the signal to background ratio is improved. The need for less tilt angle may be an advantage because the grid bars are not moved quite as close to each other, leaving a little more open area for observation. Our present detector (EDAX) and microscope (Philips 300) combination precludes moving the detector behind the microscope where it would point directly at the grid. Therefore, the angle of the specimen was changed in order to optimize the geometry between the specimen and the detector.

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