Citation

Ferree CE, Rand G. J. Exp. Psychol. 1932; 15(1): 37-55.

Copyright

(Copyright © 1932, American Psychological Association)

DOI

10.1037/h0073631

PMID

unavailable

Abstract

Speed of discrimination is not a simple logarithmic function of intensity, but is affected by changes in size of either a natural or artificial pupil. The pupil contraction is not an important factor in the slow rate of change in speed of discrimination, which takes place with increase of intensity at the higher illuminations. The pupil size is affected by the size as well as by the brightness of the illuminated areas. The intensity range for maximum pupil change is from ten to twenty foot-candles. The maximum efficiency of the eye cannot be obtained below this intensity, which the authors hold to be the natural working intensity for the eye. Speed of work in factories may be increased by increasing the intensity of light when the work is done under controlled conditions. (PsycINFO Database Record (c) 2012 APA, all rights reserved)