Independence and interaction of luminance and chromatic contributions to spatial hyperacuity performance

• Published in: Journal of the Optical Society of America. A, Optics, image science, and vision Vol. 31; no. 4; p. A394
• Main Authors: Cooper, Bonnie, Lee, Barry B
• Format: Journal Article
• Language: English
• Published: United States 01-04-2014
• Subjects: Color Perception - physiology; Humans; Psychophysics; Sensory Thresholds; Visual Acuity - physiology
• ISSN: 1520-8532
• DOI: 10.1364/JOSAA.31.00A394

Here we test interactions of luminance and chromatic input to spatial hyperacuity mechanisms. First, we tested alignment of luminance and chromatic gratings matched or mismatched in contrast polarity or grating type. Thresholds with matched gratings were low while all mismatched pairs were elevated. Second, we determined alignment acuity as a function of luminance or chromatic contrast alone or in the presence of constant contrast components of the other type. For in-phase components, performance followed the envelope of the more sensitive mechanism. However, polarity reversals revealed an asymmetric effect for luminance and chromatic conditions, which suggested that luminance can override chromatic mechanisms in hyperacuity; we interpret these findings in the context of spatial mechanisms.