Reinforcement schedules, concurrent

Higgins, S. T., 8c Stitzer, M. L. (1988). Time allocation in a concurrent schedule of social interaction and monetary reinforcement Effects of... 

The schedule which probably most resembles those operative in the human environment is known as a concurrent schedule of reinforcement. In the real world, we are routinely faced with a multitude of simultaneously operative schedule options with various schedule conditions and consequences, and we must make choices among them. The foraging (food seeking) environment of many species likewise provides such concurrent options with differential probabilities of reinforcement among which species must make choices. Concurrent schedules provide an experimental analog of this facet of the environment and require the subject to make choices among... 

Performance maintained by schedules of reinforcement represents a class of complex learned or operant behaviour. In such cases a designated response may be rewarded either on the basis of time, number of responses, response topography, stimulus characteristics, or some combination of these. In the complex human environment, many different schedules, yielding many different consequences, tend to operate concurrently. These can be simplified in a laboratory setting. Typically, schedules of reinforcement yield quite stable patterns of behaviour over prolonged periods of time, making them ideal baselines for chronic toxicity studies. 

Figure T summarizes some aspects of concurrent VI VI schedules which are important for the present discussion. The top panel illustrates that when both schedules are identical in length and both produce identical foods the sequence of responses is likely to approach a simple alternation pattern. In fact, the animal can maximize the number of reinforcers it obtains per unit time by alternately "checking" in this way whether the VI schedule on each disc is ready to provide a reinforcer. While this is an efficient way for the bird to precede, and yields a preference ratio of approximately 0.5 (which would be expected if, in fact, the bird is indifferent to the two identical foods), this alternating pattern of responding proves not to be optimal when foods with different properties are compared. Consequently, it is...

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