DIRECT EVIDENCE FOR COMPETITION BETWEEN LOCAL AND GLOBAL MECHANISMS OF 2-DIMENSIONAL ORIENTATION ILLUSIONS

Citation
P. Wenderoth et al., DIRECT EVIDENCE FOR COMPETITION BETWEEN LOCAL AND GLOBAL MECHANISMS OF 2-DIMENSIONAL ORIENTATION ILLUSIONS, Perception, 22(3), 1993, pp. 273-286
Citations number
21
Categorie Soggetti
Psychology, Experimental
Journal title
ISSN journal
03010066
Volume
22
Issue
3
Year of publication
1993
Pages
273 - 286
Database
ISI
SICI code
0301-0066(1993)22:3<273:DEFCBL>2.0.ZU;2-P
Abstract
Orientation illusions induced by two-dimensional stimuli, such as squa re outline frames or plaids, have been more or less adequately account ed for in terms of repulsion of the vertical test stimulus from the ax is of symmetry nearest vertical of the inducing stimulus, whether that axis is real or virtual. Recently, data have been obtained which dire ctly suggest a more complex mechanism: one in which the observed illus ion is the sum of all effects-complementary and antagonistic-induced b y all axes flanking vertical which are sufficiently close to vertical to exert a significant effect. Experiments are reported in which this latter ypothesis was directly tested by using nonorthogonal plaid comp onent gratings and varying the real-axis orientations while a virtual plaid axis remained fixed in orientation at 10-degrees from vertical. The data indicate that the real component gratings modulate the virtua l-axis effect.