A Critical Review of the Support for Variability as an Operant Dimension

There is abundant evidence that behavioral variability is more predominant when reinforcement is contingent on it than when it is not, and the interpretation of direct reinforcement of variability suggested by Page and Neuringer, Journal of Experimental Psychology: Animal Behavior Processes, 11(3), 429–452 (1985) has been widely accepted. Even so, trying to identify the underlying mechanisms in the emergence of stochastic-like variability in a variability contingency is intricate. There are several challenges to characterizing variability as directly reinforced, most notably because reinforcement traditionally has been found to produce repetitive responding, but also because directly reinforced variability does not always relate to independent variables the same way as more commonly studied repetitive responding does. The challenging findings in variability experiments are discussed, along with alternative hypotheses on how variability contingencies may engender the high variability that they undeniably do. We suggest that the typical increase in behavioral variability that is often demonstrated when reinforcement is contingent on it may be better explained in terms of a dynamic interaction of reinforcement and extinction working on several specific responses rather than as directly reinforced.

The impact of feedback on perceptual decision making and metacognition: Reduction in bias but no change in sensitivity

It is widely believed that feedback improves behavior but the mechanisms behind this improvement remain unclear. Different theories postulate that feedback has either a direct effect on performance through automatic reinforcement mechanisms or only an indirect effect mediated by a deliberate change in strategy. To adjudicate between these two competing accounts, we performed a large-scale study including 443 subjects; approximately half of them received trial-by-trial feedback on a perceptual task, while the other half did not receive such feedback. We found that feedback had no effect on either perceptual or metacognitive sensitivity. On the other hand, feedback significantly affected subjects’ response strategies by reducing bias and improving calibration in both the perceptual and metacognitive judgments. These results strongly support the view that feedback does not improve behavior through direct reinforcement mechanisms but that its beneficial effects stem from allowing people to adjust their strategies for performing the task.

Effects of differential training in rule-governed behavior on compliance with traffic rules by pedestrians

The aim of this translational research was to investigate the effect of differential training in three types of rule-governed behavior (RGB) on compliance and transgression with pedestrian traffic rules. Participated 231 university students divided in three groups defined by the type of training (pliance, tracking and augmenting). The design consisted of pre-tests and post-tests, in addition of a training phase with direct reinforcement according to the experimental group. The results showed a general trend by compliance the rule in all phases, particularly with tracking-consequences in pre and post-training. In all experimental groups, training in RGB increase election in compliance of traffic rules. These findings allow the formulation of evidence-based guidelines for the design, implementation and evaluation of prevention road programs.

Study of Stiffness Calculation Method on Reinforced Concrete Beam Strengthened with CFRP

The beam member should not only meet the requirement of carrying capacity but also has the ability to resist deformation. The calculation of beam deflection mainly boils down to the stiffness calculation in the existing calculation theory of deformation capacity. The flexural stiffness of concrete beams after strengthened with CFRP has been improved greatly. Direct reinforcement and sustained load reinforcement short-term stiffness calculation methods of CFRP reinforced concrete in normal service stage are derived in this article, which could be used for strengthening design.