CHAPTER VIII. The Sense of Sight: Brightness Vision (_continued_)

THE SENSE OF SIGHT: BRIGHTNESS VISION (Continued)

The delicacy of brightness discrimination--Methods of testing the dancer's ability to detect slight differences in brightness--Results of tests with gray papers--Relation of intensity of visual stimuli to the threshold of discrimination--Weber's law apparatus and method of experimentation-- Results of Weber's law tests--Practice effects, the training of vision-- Description of the behavior of the dancer in the discrimination box experiments--Modes of choice: by affirmation; by negation; by comparison-- Evidence of indiscriminable visual conditions.