THE SENSE OF SIGHT: BRIGHTNESS VISION
What is known concerning sight in the dancer--Brightness vision and color
vision--Methods of testing brightness vision, the visual discrimination
apparatus--Motives for discrimination and choice--Punishment versus reward
as an incentive in animal experiments--Hunger as an incentive--An electric
stimulus as an incentive--Conditions for brightness vision tests--
White-black vision--Evidence of preference--Check experiments--Conclusion.