Choice in a variable environment: effects of unequal reinforcer distributions.
Six pigeons were trained in a procedure in which sessions included seven unsignaled components, each offering two pecking keys, and each providing a potentially different reinforcer ratio between the two keys. Across conditions, various combinations of reinforcer ratios and reinforcer-magnitude ratios were used to create unequal reinforcer distributions between the two alternatives when averaged across a session. The results extended previous research using the same basic procedure that had included only reinforcer distributions symmetrical around 1:1. Data analyses suggested that the variables controlling choice operated at a number of levels: First, individual reinforcers had local effects on choice; second, sequences of successive reinforcers obtained at the same alternative (continuations) had cumulative effects; and, third, when these sequences themselves occurred with greater frequency, their effects further cumulated. A reinforcer obtained at the other alternative following a sequence of continuations (a discontinuation) had a large effect and apparently reset choice to levels approximating the sessional reinforcer ratio.
Landon
Jason
J
Department of Psychology, The University of Auckland, New Zealand. j.landon@auckland.ac.nz
Davison
Michael
M
Elliffe
Douglas
D
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D002755:Choice Behavior; D010856:Columbidae; D004777:Environment; D006702:Homing Behavior; D008960:Models, Psychological; D012054:Reinforcement, Psychology