The role of grouping in shape formation: New effects due to the directional symmetry

Gaze Parameters in the Analysis of Ambiguous Geometric Shapes.

This study explores perceptual organisation and shape perception when viewing a tetragon and an additional element (a dot) that is located at varying positions and distances next to the tetragon. The aim of the study is to determine the factors that can alter the interpretation of object configuration and impact whether the presented tetragon is perceived as a diamond or a square. Methods used in this study are a forced-choice task as a subjective measurement and eye tracking as an objective measurement of perceptual processes. Overall, 31 stimuli were presented to the participants: a tetragon in two different sizes with an additional element (a dot) located inside or outside the object at…

Perceptual semantics: A three-level approach

In this work we suggest a model according to which semantics has been already generated during the perception through the interaction of three dynamic levels of perceptual organization. We consider perceptual grouping as the first order processing. Shape formation is considered as the second order processing. Both grouping and shape formation can be considered as two complementary and interrelated processes of perceptual organization. The third — partially overlapping — level is meaning assignment. Most of the results are supported by empirical evidence based on new visual illusions of shape and meaning and are consistent with several other proposals (e.g., [1], [2] and [3]).

A Fuzzy Approach to the Role of Symmetry in Shape Formation: The Illusion of the Scalene Triangle

The main purposes of this work are to demonstrate the role of directional symmetry as a second order principle that polarizes the perception of the shape and to show how this preference can be easily encoded in an algorithm using a fuzzy operator for symmetry detection. The role of grouping in influencing shape perception and the role of directional symmetry was demonstrated through small triangles that create a large triangle. The specific questions answered in the psychophysical experiments were the following: Can the grouping by similarity influence both the pointing and the shape of the small and the large isosceles triangles? Conversely, can the shape of the large triangle influence th…