On the measurement of time allocation on multiple variable-interval schedules

Six pigeons were trained on a modified multiple-schedule procedure. In a three-key chamber, the center key was lighted red or green, depending upon which component schedule was in effect. A response on this key transferred this color to each of two side keys, and responses on one of those keys produced reinforcers according to the component schedule. After 2 s, the side-key lights were extinguished, the center key was reilluminated, and a further center-key response was required to give access, as before, to the component schedules. Components alternated every 3 min. This limited-access procedure allowed both times spent switched into the side keys and time spent not switched in to be measured in the two components. Component reinforcer rates were varied over eight experimental conditions. Both component response rate and component time allocation were increasing functions of relative component reinforcer rate, and these functions were not significantly different. This finding implies that local response rates (responses divided by time switched in) were unaffected by changing component reinforcer rates on multiple schedules. Because a similar result was recently obtained for concurrent schedules, models of multiple and concurrent-schedule performance may need to consider only the time allocation of behavior emitted at equal tempo in the component schedules.     

Self-schematic representation of the type A and B behavior patterns

Past research has established clear behavioral differences between Type A and B individuals. The purpose of our research was to examine how these behavioral differences are represented in the self-definitions of Type As and Bs. We investigated the existence of Type A and B self-schemata by using two tasks designed to measure the influence of these hypothetical structures on speed of processing and memory interference. During an initial task, Type As and Bs made self-relevant decisions (like me, not like me) in response to trait adjectives previously scaled as Type A, Type B, or neutral in content. Reaction times for the decisions were measured, and results indicated that both Type As and Bs made faster decisions for schema-compatible responses than for schema-incompatible responses. On a second task, Type As and Bs were tested for recognition memory after they attempted to memorize half of the aforementioned trait list. Memory errors were examined and indicated that Type As and Bs made more errors that were compatible with their respective self-schemata. Taken together, these results indicate that a Type A and B distinction forms a reliable organizing framework for the self-definitions of Type As and Bs. The existence of stable cognitive structures that parallel the behavioral differences between Type As and Bs has important implications for both theory and application.     

Stimulus Effects On Behavior Allocation In Three-alternative Choice

Six pigeons were trained on three-alternative concurrent variable-interval schedules that were available through a switching response and were signaled by colored stimuli. The discriminative stimuli for two of the schedules were always 560 nm and 630 nm, but the stimulus signaling the third alternative was varied across conditions over seven levels between these colors. For each third-alternative stimulus condition, the relative frequency of reinforcers was varied over three conditions with 4:1 and 16:1 reinforcer ratios between each pair of alternatives. The distribution of responses between the alternatives was dependent jointly on the third-alternative reinforcer rate and on the disparity between the stimulus signaling the third alternative and those signaling the other alternatives. A generalized matching approach was unable to provide invariant measures of the discriminability between constant stimuli, but a contingency-discriminability approach provided excellent fits and sensible and invariant stimulus discriminability measures.     

Commentary on high-performance computing and statistical analysis: From large-scale data analysis to smoothing functions

High-performance computing becomes essential to statistical analysis when the database is massive or the number of computations per data element is large. Albert F. Anderson (1997) discusses the application of high-performance computing to massive databases; J. O. Ramsay’s (Ramsay, Heckman, & Silverman, 1997) estimation problems potentially require large numbers of computations per data element.     

THE MUTUAL ENRICHMENT OF BASIC AND APPLIED RESEARCH IN PSYCHOLOGICAL SCIENCE AND PRACTICE

Abstract— Dealing with the problems of substance abuse requires both an appreciation of clinical reality and an understanding of basic psychosocial principles. Each of the conference presentations of theory and research most of them nonapplied in nature, created a welcome and rare occasion for experimental and clinical psychologists (and hybrids) to reflect together on the applied implications of some basic research and on the research implications of some applied professional activities. Among the issues found especially noteworthy by this discussant. Here the following the return of cognition and rational decision making as legitimate and critical foci in behavior therapy, the role of exposure to aversive events in reducing their fearsomeness, the advantages of not working doggedly to achieve goals that are better approached with a nonachievement attitude the possibility that the difficulty in altering pathological behavior derives from the properties of human language, appreciation of individual differences in psychotherapy outcome research, the importance of considering the meaning that therapeutic ministrations can have for certain patients, and the need to reexamine the utility of patients expressing their concerns.     

The control of switching into blackout during extinction

During the extinction component of a multiple variable-interval extinction schedule, four pigeons learned to peck a second key that switched off the keylights. Two experiments attempted to isolate the events that control this behavior. In the first experiment, switching into blackout was equally maintained when switches were restricted to the first minute as when they were restricted to the last minute of the extinction component. When switches could be emitted in the first and last minutes, they occurred more frequently in the first. Restricting switching to the first minute of each component and eliminating the blackout between components had no effect on switching. In the second experiment, when the stimulus correlated with extinction was omitted, switching decreased slightly. Omission of both multiple schedule stimuli decreased the switching rate, but switching was still maintained. Food reinforcement was then omitted and switching by two birds increased. Switching ceased when blackout was no longer the consequence of pecking the switching key. It was concluded that switching was not controlled by the similarity of the blackouts produced by the switching key and those that occurred between components; nor was it maintained by the temporal proximity of switching responses to the onset of the reinforced component. Finally, switching did not appear to be controlled by the main-key stimuli correlated with the components of the multiple schedule.