Measurement and modeling of behavior under fixed-interval schedules of reinforcement

Three Carneaux pigeons were exposed to various FI schedules of reinforcement to provide data for a general treatment of timing in such schedules. It was found that postreinforcement pause varied as a power function of interval length whereas breakpoint varied proportionately with interval length. A simple count-register model of timing accommodated the data and provided a flexible mechanism whose parameters could be fixed to bring it into conformation with each of J. Gibbon's (1979) types of timing systems. Response rates after the breakpoint increased with proximity to reinforcement, even though step functions were obtained when performance was summarized by averaging superimposed individual records at the breakpoint. After the pause response rates increased in a negatively accelerated fashion: An autocatalytic model of responding provides a reasonable summary of those changes. (32 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).