Davison, M. (1996).
Stimulus effects on behavior allocation in three-alternative choice.
Journal of the Experimental Analysis of Behavior,
66, 149-168.
Six pigeons were trained on three-alternative concurrent
variable-interval schedules that were available through a
switching response and were signaled by colored stimuli. The
discriminative stimuli for two of the schedules were always 560
nm and 630 nm, but the stimulus signaling the third alternative
was varied across conditions over seven levels between these
colors. For each third-alternative stimulus condition, the
relative frequency of reinforcers was varied over three
conditions with 4:1 and 16:1 reinforcer ratios between each pair
of alternatives. The distribution of responses between the
alternatives was dependent jointly on the third-alternative
reinforcer rate and on the disparity between the stimulus
signaling the third alternative and those signaling the other
alternatives. A generalized matching approach was unable to
provide invariant measures of the discriminability between
constant stimuli, but a contingency-discriminability approach
provided excellent fits and sensible and invariant stimulus
discriminability measures.
Key words: concurrent schedules, choice, stimulus control,
contingency discriminability, generalized matching, key peck,
pigeons