PREATTENTIVE EQUIVALENCE OF MULTICOMPONENT GABOR TEXTURES IN THE CENTRAL AND PERIPHERAL VISUAL-FIELD

Citation
Ga. Geri et al., PREATTENTIVE EQUIVALENCE OF MULTICOMPONENT GABOR TEXTURES IN THE CENTRAL AND PERIPHERAL VISUAL-FIELD, Vision research, 35(4), 1995, pp. 495-506
Citations number
52
Categorie Soggetti
Neurosciences,Ophthalmology
Journal title
ISSN journal
00426989
Volume
35
Issue
4
Year of publication
1995
Pages
495 - 506
Database
ISI
SICI code
0042-6989(1995)35:4<495:PEOMGT>2.0.ZU;2-#
Abstract
Similarity ratings were obtained to determine the minimum number of Ga bor components that would produce a comparison texture that appeared p reattentively similar to a 64-component standard texture. Ah textures were chosen to be both specifiable by a relatively small number of loc alized spectral components and sufficiently complex to approximate nat ural textures. The number of component orientations in the set of comp arison textures was found to be a particularly important determinant o f texture discrimination in that its effect on rated similarity was la rgely independent of the total number of components making up the text ure. Textures were also presented at 0.75 degrees and 20 degrees eccen tricity, with the latter magnified by a factor of either 2 or 4. The o verall similarity rating did not change with either magnification, whe reas the critical number of orientations, defined as the number of ori entations above which rated similarity was constant, did change for th e higher magnification. The latter finding is consistent with the prop osition that higher-order discriminations are mediated by higher corti cal areas that integrate information across the visual field. Finally, the phase-bandwidth of a set of coherent textures was also varied in order to determine whether more explicit differences in the spatial st ructure of stimuli might affect rated similarity, In contrast to the r esults for component orientation, the ratings, obtained at 0.75 degree s and 20 degrees, were different even when the phase-bandwidth stimuli were magnified by a factor of 4.