Reaction time is measured from the onset of a signal flash to the manual release of a microswitch. Responses are made by two trained subjects over wide ranges of stimulus intensity and under varying conditions of signal flash and background field luminance. Two types of experimental conditions prevail: (1) variable flash luminance at each of three field levels, and (2) variable field luminance at three constant flash intensities. Thirty-six reactions are collected for every flash-field combination at each of two fixation positions (foveal and peripheral).
The results are described by the following equation:[Equation]where B, I0, and K depend upon the field luminance.
N. R. BARTLETT and S. MACLEOD, "Effect of Flash and Field Luminance upon Human Reaction Time," J. Opt. Soc. Am. 44, 306-310 (1954)