Citation

Haupt IA. J. Exp. Psychol. 1922; 5(5): 347-379.

Copyright

(Copyright © 1922, American Psychological Association)

DOI

10.1037/h0070730

PMID

unavailable

Abstract

The present study was undertaken in the attempt to deal quantitatively with the selectiveness of the eye's response. More particularly it sought to determine the chromatic RL at seven points on the spectrum and the number of j. n. d. between the lower and upper chromatic thresholds of the four primary colors. The apparatus was designed to present to O two colored stimuli in a visual field subtending an angle of 1° 55.8' with the surrounding field either dark or equated to the brightness of the stimuli. The variations in energy of physical light required for determinations of chromatic j. n. d. from zero to maximum were effected by means of neutral grey gelatine filters and sector disks devised especially for liminal work. The method of limits was the procedure employed for arriving at the j. n. d. With the dark surrounding field it was found that liminal chromatic sensitivity increased in the following order: O, R, Y, BG, B, YG, and G. With the light surrounding field the order was: O, Y, R, YG, B, G, and BG. At the upper threshold, with the dark field, decreasing sensitivity followed the order of YG, G, O, B, BG, R, and Y; with the light field, YG, G, O, BG, B, R, and Y. In the work on chromatic discrimination with the four primary colors it was found that with the dark field Y, G, R, and B reached their maximum points of saturation at the 20th, 32nd, 40th, and 55th j. n. d. respectively; with the light field Y, G, B, and R reached their maxima at the 46th, 70th, 72nd, and 81st j. n. d. From Psych Bulletin 20:05:00336. (PsycINFO Database Record (c) 2012 APA, all rights reserved)