dc.contributor.author | Montag, Ethan | en_US |
dc.date.accessioned | 2006-12-18T16:55:57Z | en_US |
dc.date.available | 2006-12-18T16:55:57Z | en_US |
dc.date.issued | 1997-05 | en_US |
dc.identifier.citation | Journal of the Optical Society of America A 14N5 (1997) 997-1006 | en_US |
dc.identifier.issn | 0740-3232 | en_US |
dc.identifier.uri | http://hdl.handle.net/1850/3042 | en_US |
dc.description | RIT community members may access full-text via RIT Libraries licensed databases: http://library.rit.edu/databases/ | |
dc.description.abstract | The integration of color and form to produce a unified percept is a central problem in vision research. We
know that the spatial arrangement of colored stimuli influences their detectability. In the gap effect, for example,
a small gap between two colored fields enhances their discriminability [Opt. Acta 24, 159 (1977)].
Chromatic thresholds are also reduced when test fields are spatially demarcated. To explore the mechanisms
underlying these types of effect, the influence of spatial structure on chromatic sensitivity for gratings was
measured. For sine-wave and square-wave gratings modulated in different directions in color space, contrast
sensitivity was measured by using a two-alternative forced-choice procedure with a QUEST staircase. Thin
lines, of the same orientation as that of the grating, were superimposed on it at half-cycle intervals. The
phase of the superimposed lines was varied. For S-cone modulated gratings, dark lines placed at the midpoints
between peaks and troughs (90°) increased sensitivity. As the phase of the lines moved toward the
peaks (0°), their effect on sensitivity declined to zero. A similar but smaller effect was seen for isoluminant Land
M-cone modulated gratings. The superimposed lines always impaired contrast sensitivity for achromatic
gratings, especially at a phase of 0°. Spatial structure superimposed on gratings can both facilitate and impair
contrast sensitivity. In the presence of sharp boundaries, chromatic sensitivity is increased. This effect
may depend more on the salience of boundaries, since isoluminant lines superimposed on S-cone modulated
gratings and gray lines of similar cone contrast can facilitate detection if they are of sufficient contrast.
Achromatic contrast sensitivity is reduced when the boundaries are present. The additional luminance information
at the boundaries masks the grating. A simple model in which spatial integration is arrested at the
positions of the superimposed lines fits only the isoluminant conditions. For both luminance and chromatic
contrast the change in sensitivity depends on phase. | en_US |
dc.description.sponsorship | This work was supported by National Institute of Health
grants EY06398 to the author and EY01319 to the Center
for Visual Science. I am grateful to Martin S. Banks for
providing the Ideal Observer Analysis software, which I
modified for my use. | en_US |
dc.format.extent | 380547 bytes | en_US |
dc.format.mimetype | application/pdf | en_US |
dc.language.iso | en_US | en_US |
dc.publisher | Optical Society of America | en_US |
dc.relation.ispartofseries | vol. 14 | en_US |
dc.relation.ispartofseries | no. 5 | en_US |
dc.subject | Chemical sensitization | en_US |
dc.subject | Spatial structure | en_US |
dc.subject | Visual perception | en_US |
dc.title | The influence of boundary information on the perception of color | en_US |
dc.type | Article | en_US |
dc.identifier.url | http://dx.doi.org/10.1364/JOSAA.14.000997 | |