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Biomedical subjects

Igor Juricevic

Publications and source records attributed to Igor Juricevic.

5 recordsLinked to original sources
PubMed2006

Looking at perspective pictures from too far, too close, and just right.

A central problem for psychology is vision's reaction to perspective. In the present studies, observers looked at perspective pictures projected by square tiles on a ground plane. They judged the tile dimensions while positioned at the correct distance, farther or nearer. In some pictures, many tiles appeared too short to be squares, many too long, and many just right. The judgments were strongly affected by viewing from the wrong distance, eye height, and object orientation. The authors propose a 2-factor angles and ratios together (ART) theory, with the following factors: the ratio of the visual angles of the tile's sides and the angle between (a) the direction to the tile from the observer and (b) the perpendicular, from the picture plane to the observer, that passes through the central vanishing point.

Adolescent↗
PubMed2006

Foreshortening, convergence and drawings from a blind adult.

Esref is a congenitally totally blind man, practiced in drawing. He was asked to draw solid and wire cubes situated in several places around his vantage point. He used foreshortening of receding sides and convergence of obliques, in approximate one-point perspective. We note that haptics provides information about the direction of objects--the basis of perspective.

Blindness↗
PubMed2006

Blind man draws using diminution in three dimensions.

Can the principle of convergence in three spatial dimensions be reflected in drawings by the congenitally blind? A man who had been totally blind since birth was asked to draw scenes such as a tabletop with three cubes receding to the observer's left side. He used converging lines to show the tops of the cubes receding in depth. He drew the cubes to the left smaller than the cube in front of the observer. He drew faces of cubes to the left with tilted lines, pointing to below the front face of the cube in front. The result approximates three-point perspective. We note that the directions of objects from a vantage point in touch converge much as they do in vision.

Blindness↗
PubMed2005

Looking for inhibition of return in pigeons.

We conducted four experiments in order to investigate whether pigeons' responses to a recently attended (i.e., recently pecked) location are inhibited. In Experiments 1 and 2, stimulus displays were similar to those used in studies of inhibition of return (IOR) with humans; responses to cued targets tended to be facilitated rather than inhibited. In Experiments 3 and 4, birds were presented with stimulus displays that mimicked clusters of small grains and were relatively localized, which should have been more appropriate for detecting IOR in pigeons. The results from these experiments again provided evidence for facilitation of responding to cued targets, rather than for IOR.

Animals↗