|
| Recent Findings on the Disruptive Effects of Transitions Between Favorable and Unfavorable Schedules of Reinforcement |
| Saturday, May 29, 2010 |
| 1:30 PM–2:50 PM |
| Lone Star Ballroom Salon D (Grand Hyatt) |
| Area: EAB; Domain: Experimental Analysis |
| Chair: Jessica Everly (University of Pittsburgh at Greensburg) |
| Abstract: Research has shown that operant behavior is disrupted when the conditions of reinforcement shift discriminably from those that are relatively favorable to those that are relatively unfavorable. Often, this disruption takes the form of extended pausing. The purpose of this symposium is to review recent findings from laboratory settings on the disruptive effects of favorable-to-unfavorable transitions when favorability is defined in terms of reinforcer magnitude or ratio size. The speakers will discuss (a) measures of behavioral disruption under several schedules of reinforcement, including variable-ratio, fixed-ratio, and fixed-consecutive-number schedules; (b) the behavioral functions of stimuli correlated with favorable-to-unfavorable transitions using observing and escape procedures; and (c) techniques for minimizing behavioral disruption. |
| |
| The Behavioral Functions of Stimuli Correlated With Shifts in Reinforcer Magnitude |
| JESSICA EVERLY (University of Pittsburgh at Greensburg), Michael Perone (West Virginia University) |
| Abstract: The present experiment assessed whether stimuli correlated with rich and lean fixed-ratio schedule components would function as conditioned reinforcers and conditioned punishers, respectively. Pigeons responded on a mixed schedule with fixed-ratio components leading to large or small food reinforcers. Pecks on either of two observing keys converted the mixed schedule to a multiple schedule by turning on a color associated with the current component. The stimulus consequences of the observing responses were manipulated across conditions. Pecks on one observing key produced the rich or the lean stimulus, depending on the current component, whereas pecks on the other key produced one stimulus but not the other. The stimulus correlated with the large reinforcer maintained responding but the stimulus correlated with the small reinforcer did not. Although the stimulus correlated with the large reinforcer did function as a conditioned reinforcer, there was no evidence that the stimulus correlated with the small reinforcer functioned as a conditioned punisher. |
| |
| Escape from Stimuli Correlated With Transitions Across Lean and Rich Schedules of Reinforcement |
| AUGUST F. HOLTYN (West Virginia University), Michael Perone (West Virginia University) |
| Abstract: When a multiple-schedule component rich in reinforcement is followed by a component that is relatively lean, operant responding is interrupted by extended pausing and, if the procedure allows it, escape from the experimental contingencies. At issue in the present study is whether the discriminative stimulus correlated with this rich-lean transition acquires aversive functions. Four pigeons were exposed to a compound schedule with two fixed-ratio components programmed on the center key. One component ended with the delivery of a rich reinforcer (7-s access to mixed grain) and the second with a lean reinforcer (1-s access). Each component was correlated with a distinct key color. At the beginning of some components, a side key was activated. A single peck on this “stimulus termination key” replaced the discriminative stimulus on the center key with white light regardless of whether the ongoing component was rich or lean. In other words, a multiple schedule was converted to a mixed schedule. In the initial conditions, the pigeons tended to peck the stimulus termination key in the rich-lean transition. In additional conditions, underway as of this writing, the size of the fixed-ratio requirement is being raised and lowered to assess the boundary conditions of the effect. |
| |
| Pausing Following Rich-to-Lean Transitions Under Variable-Ratio Schedules: Effects of Schedule Configuration |
| ADAM T. BREWER (University of Kansas), Jeff S. Stein (University of Kansas), Patrick S. Johnson (University of Kansas), Monica T. Francisco (University of Kansas), Kathryn Saunders (University of Kansas), Dean C. Williams (University of Kansas), Gregory J. Madden (University of Kansas) |
| Abstract: Extended pausing at signaled rich-lean transitions is a robust finding observed across species, responses, and reinforcers (e.g., Galuska, 2007; Perone, 2003; Wade-Galuska et al., 2005). Research has shown that pausing may function as a form of escape from rich-lean transitions, when no explicit-escape opportunity is provided. These aversive transitions may also engender aberrant behavior in persons with intellectual disabilities (DeLeon et al., 2005). Unfortunately, basic research has not provided behavioral technologies for ameliorating disruptive behavior at these transitions. A common feature of the aforementioned literature is that subjects were exposed to transitions between fixed-ratio (FR) schedules. In general, studies have shown that variable-ratio (VR) schedules are less aversive than FR schedules (e.g., Webbe et al., 1974). Therefore, the goal of the current experiment was to reduce pausing at rich-lean transitions in a laboratory setting with a “clinician-friendly” VR schedule. Because research has suggested the size of smallest ratio controls pausing on VR schedules (Blakely & Schlinger, 1988), we manipulated the smallest ratio by including either a 1 or a 20 in the array. Pausing at rich-lean transitions was ameliorated when a 1 was the smallest ratio in the array, whereas, a 20 produced extending rich-lean pausing in all four birds. |
| |
| Effects of Shifts in Reinforcement Magnitude on Fixed-Consecutive-Number Performance in Rats |
| JULIANA M. SMITH (College of Charleston), Chad M. Galuska (College of Charleston), Adam H. Doughty (College of Charleston) |
| Abstract: On a fixed-consecutive number (FCN) schedule (Mechner, 1958), rats earn reinforcers by making at least N number of responses on Lever A followed by one response on Lever B. Early switches are not reinforced and reset the response requirement. Using the FCN procedure, this experiment studied the effects of shifts in reinforcement magnitude on FCN performance in six male Long Evans rats. Half of the components ended in a large (L) reinforcer (6 pellets) and half ended in a small (S) reinforcer (1 pellet). These components alternated irregularly yielding four transitions: SS, SL, LL, LS. Across conditions, the upcoming reinforcer magnitude was either signaled or not. FCN values (N) of 20, 40, and 60 were investigated. The results showed that a signaled upcoming large reinforcer led to more early switches than an upcoming small reinforcer, especially in the SL transition. This effect increased with increases in N. These results suggest that signaling improvements in reinforcement context may sometimes lead to a decrease in accuracy. |
|
| |