Abstract
In recent years a number of papers have investigated mechanisms of ‘perceptual grouping’ using illusory figures, specifically Kanizsa figures, as stimuli. Here we take an historical perspective on the use and meaning of the term ‘perceptual grouping’ and contrast it with the use and meaning of other similar terms such as perceptual organization, visual organization and Gestalt formation that are sometimes used interchangeably. We found that the term perceptual grouping is most commonly applied to represent the processes by which individual elements are grouped into unified wholes, for example how a formation of flying geese are perceptually grouped to comprise the figure of a V. An important characteristic of a perceptual group is that the individual elements become parts of the grouped whole. In contrast, an important quality of Kanizsa figures is that the arrangement of inducer elements leads to the construction of a unified whole that is perceptually segmented from the elements themselves: i.e. the illusory figure is occluding the inducers. Indeed the emergence of the illusory figure is historically explained as a result of perceptual segmentation, such as figure-ground or local-global segmentation. Many contemporary papers investigating Kanisza figures are in line with this explanation. As such we question the validity of using Kanizsa figures to study mechanisms of perceptual grouping and question some of the interpretations of data that conflate the two.
Meeting abstract presented at VSS 2013