Concurrent schedules: Effects of reinforcement rate and changeover delay on time allocation in a three-alternative procedure

Pigeons were exposed to a continuous choice procedure where three alternatives alternated in a fixed, recycling order (ABCABC, etc.). Responses were reinforced according to independent variable-interval schedules. For three birds, the reinforcement rate for responses on alternative C was varied. For three other birds, the duration of the changeover delay after the changeover to C was varied. For both groups, the reinforcement rates and changeover delay durations associated with A and B were constant throughout the experiment. The time proportion at A relative to B increased as a function of the reinforcement rate for responses on C and decreased as a function of the duration of the changeover delay during C. The results show that the proportion of time spent at a variable-interval alternative of a continuous choice procedure is not completely determined by the reinforcement rates provided by the alternatives. The results support the assumption that time allocation is governed by delayed reinforcement of changeover behaviour.