  The results of our experiments on categorical perception of different shades
of gray are reported. A special color generator was created for conducting the
experiments on categorizing a random sequence of colors into two classes,
light-gray and dark-gray. The collected data are analyzed based on constructing
(i) the asymptotics of the corresponding psychometric functions and (ii) the
mean decision time in categorizing a given shade of gray depending on the shade
brightness (shade number). Conclusions about plausible mechanisms governing
categorical perception, at least for the analyzed system, are drawn.
