Pigeons chose between fixed‐interval schedules of different durations presented in the
terminal links of concurrent‐chains schedules. The pair of schedules was always in the ratio …

Pigeons' responses on either of two concurrently available keys each associated with
variable‐interval 60‐sec schedules occasionally changed the schedule on that key to a …

Pigeons were trained on a two‐key choice procedure in which a pair of equal and
concurrently available variable‐interval schedules (initial links) arranged entry into one or …

Pigeons were trained on a two‐link concurrent chain schedule in which responding on
either of two keys in the initial link occasionally produced a terminal link, signaled by a …

Pigeons were trained on a two‐link concurrent chain schedule in which responses on two
keys were reinforced according to independent variable‐interval schedules by the …

Two experiments investigated the extent to which response contingencies influence the
choice between two schedules of reinforcement by exposing pigeons to a concurrent‐chains …

Six pigeons responded on concurrent‐chains schedules with either independent or
interdependent equal variable‐interval schedules in the initial links and unequal variable …

Pigeons were trained under concurrent chain schedules in which the initial links were equal
aperiodic schedules and the terminal links were fixed‐interval schedules. Choice …

Preference for constant and mixed delay of reinforcement was studied using concurrent
equal variable‐interval schedules. For four pigeons, pecking one key was reinforced …

The delay‐reduction hypothesis of conditioned reinforcement states that the reinforcing
value of a food‐associated stimulus is determined by the delay to primary reinforcement …