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A J Neuringer

Publications and source records attributed to A J Neuringer.

8 recordsLinked to original sources

Responding under discrete-trial fixed-interval schedules of reinforcement.

A fixed-interval schedule of reinforcement was modified by dividing each interval into 4-sec trial periods. No more than one response could occur during each trial because the operandum was inactivated for the remainder of any trial in which a response occurred. For example, under a 28-sec schedule, no more than seven responses could be emitted between reinforcements. Probabilities of responding by pigeons under six values of this discrete-trial fixed-interval schedule were best described by a two-state model: responding was either absent or infrequent immediately after reinforcement; then, at some variable time after reinforcement, there was an abrupt transition to a high and constant probability of responding on each trial. Performances under the discrete-trial procedure were less affected by uncontrolled sources of variance than performances under equivalent free-operant fixed-interval schedules.

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Superstitious key pecking after three peck-produced reinforcements.

The first three pecks on a response key by experimentally naive pigeons produced grain reinforcements. Thereafter, for approximately 50 experimental sessions and under a variety of schedule conditions, grain was presented independently of the subjects' behaviors. The pigeons continued to peck the response key "superstitiously" throughout the 50 sessions. The results suggest that superstitions are commonplace-not relatively infrequent or abnormal events-in the behavior of pigeons.

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Animals respond for food in the presence of free food.

Pigeons pecked a response disk to gain access to grain rewards while identical grain was freely available from a cup within the experimental chamber. Similarly, rats pressed a lever for food pellets while free pellets were present. It is not necessary, therefore, to deprive an animal of food before it will engage in instrumental responding for food. Such responding can serve as its own motivation and reward.

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Delayed reinforcement versus reinforcement after a fixed interval.

When interreinforcement intervals were equated, pigeons demonstrated little or no preference between reinforcement after a delay interval and reinforcement presented on a fixed-interval schedule. The small preferences sometimes found for the fixed interval (a) were considerably smaller than when the delay and fixed intervals differed in duration, and (b) were caused by the absence of light during the delay. These results suggest that the effects of delayed reinforcement on prior responding can be reproduced by imposing a temporally equal fixed-interval schedule in place of the delay; and, therefore, that the time between a response and reinforcement controls the probability of that response, whether other responses intervene or not.

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Separating the effects of interreinforcement time and number of interreinforcement responses.

The relative importance of interreinforcement time and interreinforcement responses was evaluated by varying each independently. To do this, a blackout was presented after each nonreinforced response under both fixed-ratio and fixed-interval schedules of reinforcement. Manipulating the blackout duration under the fixed-ratio schedule caused interreinforcement time to vary without affecting the number of interreinforcement responses. Pigeons' post-reinforcement and post-blackout response latencies were found to increase linearly with interreinforcement time. Under the fixed-interval schedule, the same blackout manipulations changed the number of interreinforcement responses without affecting interreinforcement time. Post-reinforcement and post-blackout response latencies under this condition were approximately constant. These results suggest that responding is controlled by interreinforcement time and is not influenced by the number of responses emitted between reinforcements.

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Effects of reinforcement magnitude on choice and rate of responding.

Behavior is sometimes insensitive, and sometimes extremely sensitive, to changes in reinforcement magnitude. The present work attempted to analyze this disparity by comparing, in a single experimental situation, a pigeon's choices with its response rates. Whereas choices varied directly with reinforcement duration, rates of responding were comparatively insensitive to duration changes. These results suggest that the effect of reinforcement magnitude on responding partly depends upon the extent to which responding influences the amount of reinforcement.

Animals↗

Quasi-reinforcement: control of responding by a percentage-reinforcement schedule.

When a variable-interval schedule of reinforcement was segmented into small fixed-interval components, with reinforcements following some components and brief blackouts following the others, rate of responding doubled and a positively accelerated pattern within each component was obtained. Presented according to this percentage reinforcement paradigm, the blackouts approximated the functions of a food reinforcer. These effects occurred only when the behavior sequence required to produce reinforcement was identical to that required to produce blackout. The quasi-reinforcing effects of these blackout stimuli suggest that a neutral stimulus need not occasion or accompany a primary reinforcer to acquire reinforcing properties.

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