Variations in increment thresholds as a function of background intensity and/or brightness were found to depend upon the size of the incremental flash and the magnitude of blur at the edges of the conditioning field. These findings suggest that there may be more than one visual mechanism responsible for processing intensity information.
© 1977 Optical Society of America
Edward M. Brussell, John Adkins, and Stephen R. Stober, "Increment thresholds, luminance, and brightness," J. Opt. Soc. Am. 67, 1354-1356 (1977)