When given to pigeons, the direct-acting dopamine agonist apomorphine elicits pecking. The response has been likened to foraging pecking because it bears remarkable similarity to foraging behavior, and it is enhanced by food deprivation. On the other hand, other data suggest the response is not related to foraging behavior and may even interfere…

Saccadic endpoint variability is often viewed as the outcome of neural noise occurring during sensorimotor processing. However, part of this variability might result from operant learning. We tested this hypothesis by reinforcing dispersions of saccadic amplitude distributions, while maintaining constant their medians. In a first experiment we…

Most modern research on the effects of feedback during learning has assumed that feedback is an error correction mechanism. Recent studies of feedback-timing effects have suggested that feedback might also strengthen initially correct responses. In an experiment involving cued recall of trivia facts, we directly tested several theories of…

The present study examined whether the presentation of stimuli in equivalence relations with consequences increases the operant behavior that produces these consequences. In Experiment 1, both normal words and experimentally trained equivalence stimuli did so with young children. In Experiment 2, results were similar with college students. Here, a…

Two experiments examined pigeons' postponement of a signaled extinction period, or timeout (TO), from an ongoing schedule of response-dependent food delivery. A concurrent-operant procedure was used in which responses on one (food) key produced food according to a variable-interval schedule and responses on a second (postponement) key delayed the…

To examine the effects on concurrent performance of independent manipulations of response-unit duration and number, 6 hens were exposed to concurrent second- order schedules of reinforcement. Each first-order operant unit required completion of a fixed-ratio schedule within the time specified by a fixed- interval schedule, with one further…

Contingencies of reinforcement specify how reinforcers are earned and how they are obtained. Ratio contingencies specify the number of responses that earn a reinforcer, and the response satisfying the ratio requirement obtains the earned reinforcer. Simple interval schedules specify that a certain time earns a reinforcer, which is obtained by the…

The effects of rate of conditioned reinforcement on the resistance to change of operant behavior have not been examined. In addition, the effects of rate of conditioned reinforcement on the rate of observing have not been adequately examined. In two experiments, a multiple schedule of observing-response procedures was used to examine the effects…

A model of conditional discrimination performance (Davison & Nevin, 1999) is combined with the notion that unmeasured attending to the sample and comparison stimuli, in the steady state and during disruption, depends on reinforcement in the same way as predicted for overt free-operant responding by behavioral momentum theory (Nevin & Grace, 2000).…