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.     

SPATIAL ATTENTION IN VISUAL SEARCH FOR FEATURES AND FEATURE CONJUNCTIONS

Abstract— Spatial attention was measured in visual searches tasks using a spatial probe. Both speed and accuracy measures showed that in a conjunction task, spatial attention was allocated to locations according to the presence of target features. Also, contrary to some predictions, spatial attention was used when a clearly distinguishable feature defined the target. The results raise questions about any account that assumes separate mechanisms for feature and conjunction search The probe method demonstrated here allows a very direct measurement of attentional allocation, and may uncover aspects of selection not revealed by visual search     

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.     

Performance in multiple fixed-interval schedules

The performances of five pigeons were studied under a variety of multiple fixed-interval schedules in which both component duration and reinforcement rate were varied. The three series of experimental conditions were: (a) when the ratio of component durations equalled the reciprocal of the ratio of component reinforcement rates; (b) when the component durations were equal; and (c) when the ratio of component durations equalled the ratio of component reinforcement rates. Relative response rates were related to relative reinforcement rates in the same manner as in multiple variable-interval schedules, but no effect of component duration was found.     

Concurrent schedules: Interaction of reinforcer frequency and reinforcer duration

Six pigeons were trained on concurrent variable-interval schedules with unequal reinforcer durations for the two responses. The schedules arranged on the two keys were kept equal while they were varied in absolute size. As the overall reinforcer rate was increased, both response-allocation and time-allocation measures of choice showed a trend toward indifference, and measures of sensitivity to reinforcer-duration ratios significantly decreased. Recent reports have shown that the generalized matching law cannot describe the changes in behavior allocation under constant delay-, duration-, or rate-ratios when changes are made in the absolute levels of each of these variables. The present results complement these findings by demonstrating that the concatenated generalized matching law cannot describe the interactions of two reinforcer variables on behavior allocation.     

Cues-pause-point language training: Structuring trainer statements to provide students with correct answers to questions

This study assessed the applicability of Cues-Pause-Point language training procedures in teaching students to obtain information from the statements of others. Two mentally retarded subjects, one of whom was echolalic, received training on one set of stimuli but not on another. During training the subjects were encouraged to remain quiet before, during, and briefly after the presentation of statements and then verbalize (i.e., answer a question) using the verbal cue(s) that had been presented in the statement. Correct responding reached 100% to the trained stimuli and both subjects' responding improved to the untrained stimuli. Posttests revealed that subjects used the trainer's statements to answer novel questions. The results suggest that Cues-Pause-Point procedures may be useful in teaching severely retarded individuals the functional use of observing and listening to others' verbal behavior.