This study replicated and extended Wright (2006) and Whitehurst, Ironsmith, and Goldfein (1974) by examining whether preschool aged children would increase their use of passive grammatical voice rather than using the more age-appropriate active grammatical construction when the former was modeled by an adult. Results showed that 5 of the 6…

Some researchers claim that variability is an operant dimension of behavior. The present paper reviews the concept of operant behavior and emphasizes that differentiation is the behavioral process that demonstrates an operant relation. Differentiation is conceived as change in the overlap between two probability distributions: the distribution of…

The target paper by Barba (2012) raises issues that were the focus of the author's first two publications on operant variability. The author will describe the main findings in those papers and then discuss Barba's specific arguments. Barba has argued against the operant nature of variability. (Contains 2 figures.)

In his article, the author claimed that studies of operant variability that use a lag-"n" or threshold procedure and measure the obtained variability through the change in U value fail to provide direct evidence that variability is an operant dimension of behavior. To do so, he adopted Catania's (1973) concept of the operant, which takes the…

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…

A series of experiments on operant variability by Neuringer and colleagues (e.g., Neuringer, 1986, 2002; Page & Neuringer, 1985) have been repeatedly cited as showing that behavioral variability can be reinforced by making reinforcement contingent on it. They showed that the degree of variability in pigeons' eight-peck sequences, as measured by U…

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…

The interresponse-time structures of pigeon key pecking were examined under variable-ratio, variable-interval, and variable-interval plus linear feedback schedules. Whereas the variable-ratio and variable-interval plus linear feedback schedules generally resulted in a distinct group of short interresponse times and a broad distribution of longer…

Do rats run and respond at a higher rate to run during the dark phase when they are typically more active? To answer this question, Long Evans rats were exposed to a response-initiated variable interval 30-s schedule of wheel-running reinforcement during light and dark cycles. Wheel-running and local lever-pressing rates increased modestly during…

Evidence of how behavioral research and technology have evolved together abounds in the history of the "Journal of the Experimental Analysis of Behavior" ("JEAB"). Technology from outside the discipline (exogenous) from such disciplines as electronics and computer science has been adapted for use in behavioral research. Technology from within the…

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…

This study tested the effects of post-session wheel running on within-session changes in operant responding. Lever-pressing by six rats was reinforced by a food pellet under a continuous reinforcement (CRF) schedule in 30-min sessions. Two different flavored food pellets were used as reinforcers. In the wheel conditions, 30-min operant-sessions…

Sequential theory's memory model of learning has been successfully applied in response contingent instrumental conditioning experiments (Capaldi, 1966, 1967, 1994; Capaldi & Miller, 2003). However, it has not been systematically tested in nonresponse contingent Pavlovian conditioning experiments. The present experiments attempted to determine if…

William H. Morse has played a major role in the experimental analysis of behavior. His view of operant behavior as the outcome of differential reinforcement provides an invaluable lesson in scientific research and theory. He studied schedules of reinforcement to generate an in-depth analysis of the complex interactions existing when contingencies…

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…