Inhibitory stimulus control following errorless discrimination learning

Three generalization procedures were used to investigate inhibitory stimulus control following discrimination learning with few errors. Three groups of pigeons acquired a discrimination between a green stimulus (the positive stimulus) and a vertical or horizontal line (the negative stimulus) through differential autoshaping followed by multiple schedule presentation of the two stimuli with gradually increasing stimulus durations. Genereralization testing was along a line-tilt continuum. For one group, the test involved a resistance-to-reinforcement procedure in which responses to all line tilts were reinforced on a variable-interval schedule. For a second group, also tested with the resistance-to-reinforcement procedure, the lines were superimposed on the green field that formerly served as the positive stimulus. A third group was tested in extinction with the combined stimuli. Control groups had no discrimination training but responding to green was nondifferentially reinforced. The control subjects responded more to all line tilts during testing than did the comparable experimental subjects, indicating that the negative stimulus had become an inhibitory stimulus. Both resistance-to-reinforcement groups revealed inhibitory gradients around the negative stimulus, but the gradient for the extinction group was relatively flat. These data are consistent with others that modify Terrace's early conclusion concerning the failure of inhibition to develop during errorless training.     

Second-order schedules of token reinforcement: effects of varying the schedule of food presentation

In the initial link of a complex schedule, one discriminative stimulus was presented and lever pressing produced tokens on fixed-ratio schedules. In the terminal link, signalled by a second discriminative stimulus, deposits of the tokens produced food. With two rats, the terminal link was presented after each sixth component schedule of token reinforcement was completed. With the other two rats, the terminal link was presented following the first component schedule completed after a fixed interval. During the terminal link, each token deposit initially produced food. The schedule of food presentation was subsequently increased such that an increasing number of token deposits in the terminal link was required for each food presentation. Rates of lever pressing in the initial link were inversely related to the schedule of food presentation in the terminal link. These results are similar to those of experiments that have varied schedules of food presentation in chained schedules. Rates and patterns of responding controlled throughout the initial link were more similar to those ordinarily controlled by second-order brief-stimulus schedules than to those controlled by comparable extended chained schedules.     

Persistence of acquired behavioral control in the context of imprinting

Newly hatched Khaki Campbell ducklings (Anas platyrhynchos domesticus) were exposed to a moving object that immediately suppressed distress vocalizations occurring in a novel environment. The static visual and auditory features of this object acquired the ability to suppress distress vocalizations after eight 20-min sessions of exposure to the object in motion. The acquired suppressive properties of these features were found to persist throughout thirty 20-min sessions given over 10 days. During these sessions, the ducklings were continually exposed to the static features in the absence of visual movement. In a second experiment, the ability of these features in the absence of visual movement. In a second experiment, the ability of these features to serve as reinforcement for a pecking response was shown to persist for up to 56 hr. In one duckling, presentations of the static visual features did not maintain pecking behavior. However, it was shown that pecking responses could be re-instated in this duckling by introducing novel stimuli to the environment.     

Within‐subject analysis of a prevention strategy for problem behavior

Although decades of research on functional analysis methodology have identified common contingencies that maintain problem behavior and effective interventions, relatively little research has been conducted on strategies to prevent the initial development of problem behavior. We conducted a 2‐part case study, the purposes of which were to illustrate the use of sensitivity tests as the bases for intervention (Study 1) and subsequently to assess the efficacy of a prevention strategy using a single‐subject design (Study 2). Results showed that the sensitivity tests identified establishing operations that may set the occasion for the development of problem behavior and that interventions based on differential reinforcement prevented increases in the severity of problem behavior relative to untreated and control baselines. Benefits and limitations to this individualized approach to prevention are discussed.     

Behavioral momentum theory fails to account for the effects of reinforcement rate on resurgence

The behavioral‐momentum model of resurgence predicts reinforcer rates within a resurgence preparation should have three effects on target behavior. First, higher reinforcer rates in baseline (Phase 1) produce more persistent target behavior during extinction plus alternative reinforcement. Second, higher rate alternative reinforcement during Phase 2 generates greater disruption of target responding during extinction. Finally, higher rates of either reinforcement source should produce greater responding when alternative reinforcement is suspended in Phase 3. Recent empirical reports have produced mixed results in terms of these predictions. Thus, the present experiment further examined reinforcer‐rate effects on persistence and resurgence. Rats pressed target levers for high‐rate or low‐rate variable‐interval food during Phase 1. In Phase 2, target‐lever pressing was extinguished, an alternative nose‐poke became available, and nose‐poking produced either high‐rate variable‐interval, low‐rate variable‐interval, or no (an extinction control) alternative reinforcement. Alternative reinforcement was suspended in Phase 3. For groups that received no alternative reinforcement, target‐lever pressing was less persistent following high‐rate than low‐rate Phase‐1 reinforcement. Target behavior was more persistent with low‐rate alternative reinforcement than with high‐rate alternative reinforcement or extinction alone. Finally, no differences in Phase‐3 responding were observed for groups that received either high‐rate or low‐rate alternative reinforcement, and resurgence occurred only following high‐rate alternative reinforcement. These findings are inconsistent with the momentum‐based model of resurgence. We conclude this model mischaracterizes the effects of reinforcer rates on persistence and resurgence of operant behavior.     

An integrated model for guiding the selection of treatment components for problem behavior maintained by automatic reinforcement

We evaluated the usefulness of 2 assessments to guide treatment selection for individuals whose prior functional analysis indicated that automatic reinforcement maintained their problem behavior. In the 1st assessment, we compared levels of problem behavior during a noncontingent play condition and an alone or ignore condition. In the 2nd, we assessed participants’ relative preferences for automatic reinforcement and social reinforcers in a concurrent‐operants arrangement. We used the results of these 2 assessments to assign 5 participants to a treatment based on noncontingent access to social reinforcers or to a treatment based on differential access to social reinforcers. We conducted monthly probes with the participants over 10 to 12 months to evaluate the effects of the treatment procedures. All participants showed reductions in problem behavior over this period.     

Individual and combined effects of noncontingent reinforcement and response blocking on automatically reinforced problem behavior

Noncontingent reinforcement (NCR) and response blocking are 2 common interventions for problem behavior maintained by automatic reinforcement. We implemented NCR and blocking with 1 boy and found this combined intervention to be effective at decreasing high rates of automatically reinforced pica. With another child, we compared the effects of blocking alone to the combined intervention. With the third child, we compared NCR alone and blocking alone to the combined intervention. Results showed that the combined intervention was effective at reducing automatically reinforced problem behavior while moderate to high levels of item engagement maintained. When evaluated individually, neither NCR nor blocking was sufficient to reduce problem behavior to clinically significant levels.     

Stability of daily preference across multiple individuals

Preference stability provides clues about the extent to which a clinician might be able to deliver a particular stimulus contingent on behavior as a reinforcer. Previous research has been somewhat mixed in terms of evidence for preference stability. Results of the current study are consistent with studies that have reported correlations between preference assessments, suggesting that preferences are relatively stable across time.