Successive discrimination training with equated reinforcement frequencies: failure to obtain behavioral contrast

In two experiments, pigeons were trained on two-component multiple schedules in which responding in one component (S₁) was always maintained by a variable-interval schedule. In Experiment I, low response rates were reinforced in the second (S₂) component for six master subjects. This schedule was adjusted to equate reinforcement frequencies in the two components. These subjects were compared to yoked partners, for which reinforcement in the S₂ component was made available on a variable-interval schedule whose value was determined by the master subjects. A similar procedure was used in Experiment II, where the S₂ schedule for master subjects made reinforcers contingent on the absence of responding. No evidence was found in either experiment for a behavioral contrast effect in the S₁ component attributable to response reduction in the S₂ component. A reliable contrast effect was obtained from a group of pigeons given extinction conditions in the S₂ component, which was compared to a group maintained throughout on a multiple variable-interval schedule. The results suggest that previous indications of behavioral contrast in similar situations were probably caused by uneven reinforcement distributions or reflect uncontrolled fluctuations in response rates.     

What are we doing to waiting list controls?

For ethical reasons waiting list controls have been preferred to no treatment controls, provided the wait is still shorter than that for routine services. However, could significant differences arise from the wait being detrimental rather than the intervention being beneficial? Despite the number of studies employing this design, few have analysed intervention trials from the perspective of the waiting list controls rather than the experimental group. A Full Day Stress Management Workshop programme which had run successfully in Birmingham, was repeated in three areas in the South East of England. The data from the four areas were reanalysed to assess progress within the control group and to compare the final assessment points for the two groups. The control group did not show any significant deterioration during the three month wait for their workshop. Three months after their respective workshops, scores in the control groups did not differ significantly from those of the experimental group.     

The effects of monitoring environment on problem-solving performance

While effective and efficient solving of everyday problems is important in business domains, little is known about the effects of workplace monitoring on problem-solving performance. In a laboratory experiment, we explored the monitoring environment’s effects on an individual’s propensity to (1) establish pattern solutions to problems, (2) recognize when pattern solutions are no longer efficient, and (3) solve complex problems. Under three work monitoring regimes—no monitoring, human monitoring, and electronic monitoring—114 participants solved puzzles for monetary rewards. Based on research related to worker autonomy and theory of social facilitation, we hypothesized that monitored (versus non-monitored) participants would (1) have more difficulty finding a pattern solution, (2) more often fail to recognize when the pattern solution is no longer efficient, and (3) solve fewer complex problems. Our results support the first two hypotheses, but in complex problem solving, an interaction was found between self-assessed ability and the monitoring environment.