Title:
Do color appearance judgments interfere with detection of small threshold stimuli?

Abstract:
The application of adaptive optics to vision science creates the potential to directly probe the link between the retinal mosaic and visual perception. However, interrogation on a cellular level requires small, threshold stimuli and therefore an implicit detection model. Unfortunately the parameters governing detection at cone threshold are poorly constrained, and whether or not appearance judgments interact with detectability under these conditions is unknown. We tested the assumption that subjects can report stimulus appearance without compromising sensitivity by having four subjects rate either detection certainty, color appearance, or both, for small, brief, monochromatic (580 nm) point stimuli presented to the dark adapted fovea. Reporting color, either alone or in conjunction with detection certainty, did not impair detection. Sensitivity actually increased in the simultaneous reporting task, while color reports were effectively unaltered. These results suggest that 1. color mechanisms contain information relevant for detection at cone threshold, 2. subjects cannot voluntarily make full use of this information in a simple detection task, and 3. simultaneous reporting is a viable method of investigating multiple stimulus attributes for small threshold stimuli.