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Previous research has shown that extended exposure to delayed reinforcement results in less impulsive choice in a subsequent delay-discounting task. Some work also suggests the opposite effect: extended exposure to immediate reinforcement may result in more impulsive choice behavior in a subsequent delay-discounting task. Understanding the impact that learning histories have on impulsive choice is important and clinically relevant because of the relationship between a strong preference for smaller-sooner over larger-later reinforcement (i.e., impulsive choice) and a myriad of other problematic health behaviors, such as substance misuse. In the present experiment, we exposed 24 rats to an immediate reinforcement intervention and 24 rats to a maturation/handle control group, followed immediately by a delay-discounting task. The procedure was designed as a systematic replication that accounted for several limitations from recent similar work. Results indicated that exposure to immediate reinforcement modestly increased impulsive choice in the delay-discounting task, but the effect was not overwhelming. These findings are consistent with previous work and have implications for understanding how experience-based interventions may affect clinically relevant impulsive choice. [ABSTRACT FROM AUTHOR]

Behavior and events distributed in time can serve as markers that signal delays to future events. The majority of timing research has focused on how behavior changes as the time to some event, usually food availability, decreases. The primary objective of the two experiments presented here was to assess how behavior changes as time passes between two time markers when the first time marker was manipulated but the second, food delivery, was held constant. Pigeons were exposed to fixed-interval, response-initiated fixed-interval, and signaled response-initiated fixed-interval 15- and 30-s schedules of reinforcement. In Experiment 1, first-response latencies were systematically shorter in the signaled response-initiated schedules than response-initiated schedules, suggesting that the first response was a more effective time marker when it was signaled. In Experiment 2, responding in no-food (i.e. 'peak') trials indicated that timing accuracy was equivalent in the three schedule types. Compared to fixed interval schedules, timing precision was reduced in the signaled response-initiated schedules and was lowest in response-initiated schedules. Results from Experiments 1 and 2 coupled with previous research suggest that the overall 'informativeness' of a time marker relative to other events and behaviors in the environment may determine its efficacy. [ABSTRACT FROM AUTHOR]

Aversive control is a common method to reduce undesirable behavior in horses. However, it often results in unintended negative side effects, including potential abuse of the animal. Procedures based on positive reinforcement, such as differential reinforcement of other behavior (DRO), may reduce undesirable behaviors with fewer negative consequences. The current study used DRO schedules to reduce pawing using a multiple baseline design across 3 horses. Results indicated that DRO schedules were effective at reducing pawing. However, individual differences in sensitivity to DRO and reinforcer efficacy may be important considerations. [ABSTRACT FROM AUTHOR]

Different events can serve as time markers that initiate intervals in schedules of reinforcement. Pigeons were exposed to fixed-interval (FI) schedules in which the onset of the interval was signaled by the illumination of a key light or initiated by a peck to a lighted key. Food was delivered following the first response after the interval elapsed. In Experiment 1, three pigeons were exposed to a multiple schedule. One component was a standard FI schedule: Key light illumination signaled the onset of the interval. The other component was a response-initiated fixed-interval (RIFI) schedule: The first key-peck response determined the onset of the interval. In Experiment 2, three pigeons were exposed to a multiple FI-RIFI schedule of reinforcement and on occasional trials food was not delivered (i.e. "no-food" or "peak trials"). A yoking procedure equated reinforcement rates between the schedule types in both experiments. Absolute response rates early in the intervals were higher in the RIFI schedules of both experiments. Normalized response-rate gradients, ogive fits of normalized response gradients, and breakpoints were not systematically different for the schedule types in Experiment 1, indicating similar patterns of responding between interval onset and food delivery. However, during peak trials in Experiment 2 the duration of responding at a high rate was longer for RIFI schedules than FI schedules. This suggests that timing precision was reduced in the RIFI schedules and that relative "distinctiveness" of a time marker may determine its efficacy. [ABSTRACT FROM AUTHOR]

The present study investigated the effects of punishing responses inconsistent with rules on instructional control during a choice task. In a procedure modeled after Hackenberg and Joker (1994), 7 adults were presented with repeated choices between progressive- and fixed-time schedules of reinforcement and were given instructions (rules) for how to respond to maximize earnings. Across sessions, the progressive-time schedule step size was manipulated so that the instructions became increasingly inaccurate, and deviating from the instructions produced greater earnings. The experiment consisted of two phases, Penalty and No Penalty. During the Penalty phase, deviating from the instructions produced a money-loss penalty (response-cost punishment). Two participants showed persistent instructional control and therefore completed only one phase (Penalty or No Penalty), and 1 participant showed little instructional control during the Penalty phase until the punishment magnitude was increased. In all 4 participants who experienced both Penalty and No Penalty phases, punishment increased the consistency of choices with the instructions, and in 2 of these participants punishment increased the progressive-schedule step size at which choices began to systematically deviate from the instructions. These results show that monetary penalties for breaking with rules may enhance instructional control, but that deviations from rules still occur under punishment when such deviations produce greater reinforcement than rule following. [ABSTRACT FROM AUTHOR]

Abstract: Biting and chewing by horses on crossties can result in injury to the handler and damage to equipment. Operant-conditioning techniques have been used to train horses and could be used to reduce or eliminate undesirable biting and chewing. Presently, a differential-reinforcement-of-other-behavior (DRO) schedule, in the context of a reversal design, was effective in reducing biting and chewing in two horses. In DRO schedules, a reinforcer is delivered contingent on the absence of a target behavior for a specified interval. Positive-reinforcement procedures offer an alternative to aversive-control techniques typically used in equine training and may provide for better equine welfare and horse–human interaction. [Copyright &y& Elsevier]