Visual slant underestimation

Observers frequently underestimate the in-depth slant of rectangles under reduction conditions. This also occurs for slanted rectangles depicted on a flat display medium. Perrone (1982) provides a model for judged slant based upon properties of the 2-D trapezoidal projection of the rectangle. Two important parameters of this model are the angle of convergence of the sides of the trapezoid and the projected length of the trapezoid. This model was tested using a range of stimulus rectangles and found that the model failed to predict some of the major trends in the data. However, when the projected width of the base of the trapezoid projection was used in the model, instead of the projected length, excellent agreement between the theoretical and obtained slant judgements resulted. The good fit between the experimental data and the new model predictions indicates that perceived slant estimates are highly correlated with specifiable features in the stimulus display

Visual orientation illusions: Global mechanisms involved in hierarchical effects and frames of reference

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The visual determinants of the rod-and-frame illusion.

The research reported in this thesis developed from two experiments previously reported by Beh, Wendetoth and Purcell (1971) and Deb and Wenderoth (1972), which were concerned with illusiOns induced by tilted outline frames, and particularly with a theoretical account of the results in terms of the "major axes hypothesis"

The angular function of an aftereffect of slant : a methodological study.

The aim of this investigation was to measure the angular (distance) function of a "three-dimensional" slant aftereffect (AE), in order to test certain hypotheses concerning the determinants of the effect. Previous attempts to measure the relationship between the magnitude of slant AE and angle of slant of the inducing (I) figure have not been satisfactory (Kohler and Emery, 1947; Bergman and Gibson, 1959; Wenderoth, 1963)

Theory of real space imaging of Fermi surfaces

A scanning tunneling microscope can be used to visualize in real space Fermi surfaces with buried impurities far below substrates acting as local probes. A theory describing this feature is developed based on the stationary phase approximation. It is demonstrated how a Fermi surface of a material acts as a mirror focusing electrons that scatter at hidden impurities.Comment: 10 pages, 4 figure

Time Estimation Predicts Mathematical Intelligence

Background: Performing mental subtractions affects time (duration) estimates, and making time estimates disrupts mental subtractions. This interaction has been attributed to the concurrent involvement of time estimation and arithmetic with general intelligence and working memory. Given the extant evidence of a relationship between time and number, here we test the stronger hypothesis that time estimation correlates specifically with mathematical intelligence, and not with general intelligence or working-memory capacity. Methodology/Principal Findings: Participants performed a (prospective) time estimation experiment, completed several subtests of the WAIS intelligence test, and self-rated their mathematical skill. For five different durations, we found that time estimation correlated with both arithmetic ability and self-rated mathematical skill. Controlling for non-mathematical intelligence (including working memory capacity) did not change the results. Conversely, correlations between time estimation and non-mathematical intelligence either were nonsignificant, or disappeared after controlling for mathematical intelligence. Conclusions/Significance: We conclude that time estimation specifically predicts mathematical intelligence. On the basis of the relevant literature, we furthermore conclude that the relationship between time estimation and mathematical intelligence is likely due to a common reliance on spatial ability