Lightness induction in the S-cone pathway

Lightness induction is classically regarded as a contrast phenomenon limited to pathways which process luminance information. To determine if lightness induction can also occur in the chromatic domain, this phenomenon was studied with stimuli visible only to the short wavelength sensitive (S)-cones which have post-receptoral connections limited to chromatic pathways. The lightness of an object visible only to S-cones was found to be dependent on the relative intensity of its background in a manner similar to achromatic, luminance stimuli. Less intense (dark) backgrounds made the object appear lighter, while more intense (light) backgrounds made the same object appear darker. These results indicate a commonality among lightness induction effect in the processing of chromatic and luminance information.