Influence of rod signals on hue perception: evidence from successive scotopic contrast.

In successive scotopic color contrast, a colored adapting field induces a hue into a successively presented, purely rod-detected test field. To determine the rod influence on hue perception, a comparison was made, for both spectral matches and hue names, between photopic and scotopic color contrast hues produced by the same adapting fields adjusted to each of the four unique hues. Rod signals evoked hues reflecting each direction of both red/green and blue/yellow hue dimensions. Rod signals differentially strengthened blue relative to red or green hue components under some conditions but not under others. No other differential rod influences on hue were found.