Aversive CS control of instrumental avoidance as a function of selected parameters and method of Pavlovian conditioning

Effects of aversive CSs upon dogs' instrumental avoidance responding were assessed as a function of the Pavlovian conditioning parameters using off-baseline (Experiment 1) and on-baseline (Experiment 2) conditioning procedures. In each experiment, three UCS intensitites (2, 6, and 10 mA) were crossed factorially with two CS-UCS intervals (10 and 90 sec) yielding six groups. After 4 days of conditioning, the CS-produced effects on avoidance were determined primarily by an interaction between Pavlovian procedure (off- versus on-baseline) and UCS intensity. With off-baseline conditioning, CS-produced facilitation of avoidance was an increasing function of the UCS intensity. However, with on-baseline conditioning, only the CS paired with weak UCS facilitated avoidance, and the CS paired with the strong UCS suppressed responding. This reversing parametric function poses problems for two-process motivational theories of avoidance.     

The sensory basis of avoidance responding in the rat : Relative dominance of auditory or visual warning signals and safety signals

Three experiments determined the relative degree of stimulus control exerted by the elements of a compound auditory-visual stimulus when this stimulus was presented in various temporal relationships to a barpress avoidance response. When the compound discriminative stimulus for barpress avoidance responding consisted of onset of white noise and onset of either light or darkness, the white noise always exerted dominant control. When the compound discriminative stimulus consisted of offset of white noise and onset of light, neither element controlled avoidance responding. On the other hand, when a barpress avoidance response produced a compound feedback stimulus consisting of onset of white noise and onset of either light or darkness, the visual element always exerted dominant control. When the compound feedback stimulus consisted of offset of white noise and onset of light, both elements exerted stimulus control.     

Effects of schedule and magnitude of reinforcement under conditions of thirst motivation

In contrast to a recent finding (Macdonald, G. E., & De Toledo, L. Learning and Motivation, 1974, 5, 288–298.) the results of three experiments investigating various partial reinforcement (PRF) manipulations under conditions of thirst motivation demonstrated strong similarity to analogous manipulations involving food reward. Specifically, for animals receiving water reinforcement, PRF was shown to generate greater resistance to extinction than continuous reinforcement (Expt 1 & 3), the schedule of reinforcement was shown to interact with level of acquisition (Expt 1 and 2), and the magnitude of the partial reinforcement extinction effect was shown to be a function of reward magnitude (Expt 3). These results provide strong evidence that mechanisms which operate in partial reinforcement situations are highly similar, regardless of the type of appetitive reinforcement.     

Group caution at the race track

McCauley, Stitt, Woods and Lipton's finding that groups were more conservative than individuals when betting at a race track has been criticized on statistical and methodological grounds. The present study which does not suffer the shortcomings for which McCauley et al. were legitimately criticized does, nonetheless, sustain their general results and conclusions. Groups were significantly more cautious than individuals when wagering $2.00 on a horse race.     

The Harvard Pigeon Lab under Herrnstein

The history of the Harvard Pigeon Lab is a history of two periods of remarkable productivity, the first under Skinner's leadership and the second under Herrnstein's. In each period, graduate students flocked to the leader and then began stimulating one another. Chance favored Herrnstein's leadership, too, because an unusually large number of graduate students were admitted in the fall of 1962. In each period, productivity declined as the leader lost interest in the laboratory and withdrew. Directly and indirectly, the laboratory finally died as a result of the cognitive "revolution." Skinner and his students saw the possibility of a natural science of behavior and set about establishing that science based on concepts such as response rate, stimulus control, and schedules of reinforcement. Herrnstein and his students saw that the science could be quantitative and set about making it so, with relative response rate, the matching law, and the psychophysics of choice (analogous to S. S. Stevens' psychophysics). The history might provide a golden research opportunity for someone interested in the impact of such self-organizing research groups on the progress of science.     

Steps and pips in the history of the cumulative recorder

From its inception in the 1930s until very recent times, the cumulative recorder was the most widely used measurement instrument in the experimental analysis of behavior. It was an essential instrument in the discovery and analysis of schedules of reinforcement, providing the first real-time analysis of operant response rates and patterns. This review traces the evolution of the cumulative recorder from Skinner's early modified kymographs through various models developed by Skinner and his colleagues to its perfection in the 1950s, and then into the 1960s when it proliferated as different scientific instrument companies began marketing their own models of the cumulative recorder. With the rise of digital computers, the demise of the cumulative recorder as a scientific instrument was inevitable; however, the value of the cumulative record as a monitoring device to assess schedule control of behavior continues. The cumulative recorder remains, along with the operant conditioning chamber, an icon of Skinner's approach to psychology.     

Science and Human Behavior: a tutorial in behavior analysis

B. F. Skinner's Science and Human Behavior (1953) became the main source of my understanding of behavior during my first semester as a college professor in 1955 at Kansas University. It has continued to exert a major influence throughout my career as the basis for a completely deterministic science of behavior, as a handbook to be consulted as a first step in dealing with any issue in behavior analysis, and as a tutorial in behavioral interpretive analysis--in the use of a small number of behavioral concepts and principles to understand behavior of all degrees of complexity. I describe four general interpretive orientations or maxims that are of broad significance for behavior analysis, and also two underappreciated major theoretical contributions.