Citation

Cobb PW. J. Exp. Psychol. 1916; 1(5): 419-425.

Copyright

(Copyright © 1916, American Psychological Association)

DOI

10.1037/h0073634

PMID

unavailable

Abstract

Describes a modification of the apparatus used in studying the effect on foveal vision of bright surroundings. The new method is additive, which means that the difference between the two halves of the field is obtained by superposing an additional brightness upon one half of a constantly visible field of uniform brightness. The second change consists in the projection of the test field by lens. The diagrammatic representation of the principle of the optical system is given. Concludes by describing the advantages of this apparatus over the previous ones. The small extent of the diffusing medium decreased the magnitude of both the inequalities in its properties and those of its illumination. The point of equality of the two halves of the field was established in the physical sense when no addition was permitted to either half of the field. The method used permitted the measurement of the difference separately and directly. (PsycINFO Database Record (c) 2012 APA, all rights reserved)