Collateral responding during differential reinforcement of low rates

Two pigeons were trained to peck either of two response keys for food, under two different variable-interval schedules. When responding stabilized, the schedule on the left key (reinforcement-key) was changed to a differential-reinforcement-of-low-rates schedule, and responses on the right key (extinction-key) were no longer reinforced. The mean interresponse time of responses on the reinforcement-key approximated the temporal requirement of the reinforcement schedule on that key. Collateral responding on the extinction-key was maintained by one of the birds. A “run” of these collateral responses was defined as a sequence of responses on the extinction-key occurring between two responses on the reinforcement-key. For this one bird, collateral behavior, measured by mean time per run and mean number of responses per run, was an increasing function of the temporal requirements of the reinforcement schedule on the reinforcement key, and it was strongly positively correlated with the mean interresponse time of responses on the reinforcement-key. However, from an analysis of the results, the collateral behavior did not appear to have mediated the temporal spacing of responses on the reinforcement-key.     

"Warmup" and "cooldown" in Sidman avoidance behavior of rats: A dual-process interpretation

The present experiment investigated relations between "warmup" in unsignalled Sidman avoidance in rats and the intensity of shock. Magnitude of shock-rate change was quantified by comparing the rat's behavior during the initial third and the final two thirds of the same session. Warmup was said to occur whenever the shock rate during the initial 20 min was higher than the shock rate during the final 40 min of a 60 min session. "Cooldown" was defined as lower shock rate during the initial 20 min than during the final 40 min. Warmup was observed when shocks were intense, cooldown was observed when shocks were low intensity, and neither was observed when medium-intensity shocks were administered. Response-rate changes were correlated with shock-rate changes, but were smaller. The results are interpreted within the framework of a dual-process theory of habituation.     

Using differential reinforcement of low rates to reduce children's requests for teacher attention

We evaluated the effectiveness of full-session differential reinforcement of low rates of behavior (DRL) on 3 primary school children's rates of requesting attention from their teacher. Using baseline rates of responding and teacher recommendations, we set a DRL schedule that was substantially lower than baseline yet still allowed the children access to teacher assistance. The DRL schedule was effective in reducing children's requests for assistance and approval, and the teacher found the intervention highly useful and acceptable. The possible mechanisms that account for behavior change using full-session DRL schedules are discussed.     

The effects of differential reinforcement on generalized imitation

The present study examines the transfer of imitative learning to other nonimitative performance conditions and compares imitative and nonimitative performance under contingencies of differential reinforcement for S⁰ behavior, differential reinforcement for nonimitative behavior, and extinction. Many authors have suggested that a child's continued imitative performance of rewarded S^D and unrewarded S^Δ behavior is a function of subtle social cues or experimental demand present in most generalized imitation procedures. The two experiments presented here support that conclusion but also provide evidence that conclusions drawn from such generalized imitation studies were generally accurate. Even though a child's trial-by-trial imitative performance appeared to be a function of procedural artifacts, the child's later performance in the role of a model indicated that a functionally interdependent generalized response class of imitative behavior had been learned while the child imitated. As such, these experiments generally supported Baer's secondary reinforcement hypothesis for imitative performance and suggest that future research employ nonimitative tasks such as reversed imitation as a measure of imitative learning.     

Generalization peak shift in rats under conditions of positive reinforcement and avoidance

Rats were trained to discriminate between two click frequencies. One frequency was associated with either variable-interval food reinforcement (Experiment 1) or free-operant avoidance (Experiment 2). The other frequency was associated with the absence of food in Experiment 1 and the absence of shock in Experiment 2. On a click frequency generalization test, the rats in both experiments showed positive peak shift with the shape of the relative gradients being very similar. This is the first reported instance of peak shift in rats when responding was maintained by an avoidance contingency. Nondifferentially trained controls showed that this shift was due exclusively to associative processes, with nonassociative stimulus factors in themselves apparently making no contribution to increased rates at particular stimulus values. These results show the comparability of appetitive and aversive control and support the position that gradient differences do not result from approach versus avoidance per se.     

Using self‐monitoring and differential reinforcement of low rates of behavior to decrease repetitive behaviors: A case study

We used a reversal design to evaluate the effects of a self‐monitoring system and differential reinforcement of low rates of behavior on decreasing repetitive body movements in a child with autism. A trial‐based functional analysis revealed that repetitive body movements were maintained by automatic reinforcement. Treatment consisted of teaching the participant to use a self‐monitoring system to monitor the occurrence of repetitive body movements. A stimulus control analysis revealed the self‐monitoring system acquired stimulus control over the repetitive body movements, in that they were more likely to occur in the absence of the system than in its presence. The self‐monitoring system was implemented with a differential reinforcement of low rates of behavior, and their combined effects were evaluated within a reversal design. Repetitive body movements decreased with the implementation of the treatment. The use of self‐monitoring systems to target problem behavior is discussed.     

Effects of differential rates of alternative reinforcement on resurgence of human behavior

Despite the success of exposure‐based psychotherapies in anxiety treatment, relapse remains problematic. Resurgence, the return of previously eliminated behavior following the elimination of an alternative source of reinforcement, is a promising model of operant relapse. Nonhuman resurgence research has shown that higher rates of alternative reinforcement result in faster, more comprehensive suppression of target behavior, but also in greater resurgence when alternative reinforcement is eliminated. This study investigated rich and lean rates of alternative reinforcement on response suppression and resurgence in typically developing humans. In Phase 1, three groups (Rich, n = 18; Lean, n = 18; Control, n = 10) acquired the target response. In Phase 2, target responding was extinguished and alternative reinforcement delivered on RI 1 s, RI 3 s, and extinction schedules, respectively. Resurgence was assessed during Phase 3 under extinction conditions for all groups. Target responding was suppressed most thoroughly in Rich and partially in Lean. Target responding resurged in the Rich and Lean groups, but not in the Control group. Between groups, resurgence was more pronounced in the Rich group than the Lean and Control groups. Clinical implications of these findings, including care on the part of clinicians when identifying alternative sources of reinforcement, are discussed.     

A wood-gnawing sensor for recording collateral behavior emitted by rats on differential reinforcement of low rate schedules

The difficulties in measuring the idiosyncratic collateral behavior emitted by rats on a DRL schedule are overcome by providing woodblocks attached to a sensor. Wood gnawing is recorded by stylus transducer signals. An audio amplifier raises these signals to a suitable level for the operation of a threshold control unit. A pulse former operates the final relay amplifier for 150 msec from the onset of disturbance to the transducer.     

Correlative effects of psychogenetic selection: A study of the roman high and low avoidance strains of rats

A sample of 86 rats of the RHA and RLA strains, selectively bred in Rome for speed of acquisition of conditioned avoidance responses (CAR), was given the open-field test of emotionality, and re-tested for conditioning in their new environment. Both sexes were included in a balanced-order design. The standardized open-field test and a conventional shuttle-box with buzzer as the conditioned stimulus and shock as the unconditioned stimulus were used. The results show that the Roman strains do not differ in respect of open-field defecation. While the RHA strain was confirmed as superior in measures of CAR formation, it was also found to be significantly more active both in the open-field (ambulation) and in inter-trial activity during conditioning. No effects attributable either to order of test administration or the previous history of the subjects were detected, and those due to their sex merely confirmed previous findings. These results are contrasted with the findings for the Maudsley strains of reactive and non-reactive rats which differ significantly in respect of emotional elimination as a result of a similar selection procedure, but which also display a similar difference in CAR acquisition and in mature body weight.     

Participation of hippocampal cholinergic system in memory persistence for inhibitory avoidance in rats

Memory persistence needs a new event of consolidation 12h after the acquisition. We investigated the role of the cholinergic activity on the persistence of memory. For this purpose, we performed the treatments 9 or 12h after acquisition and the memory tested 2 or 7 days after inhibitory avoidance (IA) training. Here we report that activity of medial septum, by transitorily inactivating this structure with lidocaine 12h after IA training, is essential for memory persistence at the 7th day, but not for the formation at the 2nd day. We also report that muscarinic and nicotinic cholinergic receptors of CA1 area are engaged on memory persistence. Since scopolamine (mAChRs antagonist) and mecamylamine (nAChRs blocker) infusions, 12h post-training, demonstrated impairment on long term memory (LTM), persistence on the 7th day but no effect on LTM formation was found on the 2nd day in the IA test. The same effects were found with pirenzepine, an M1 antagonist. No effects on the formation and persistence of memory on the 2nd and 7th days were demonstrated after DHβE infusions (nAChRs subtype antagonist α4β2, α3β2). These findings suggest that mAChR and nAChR at the CA1 area, and also MS activation, are required for the persistence of memory.     

The effects of noncontingent reinforcement on task disengagement following failure of differential reinforcement treatment

Following the failure of applications of differential reinforcement (DR), the effects of reinforcement delivered noncontingently (NCR) on task disengagement and task completion were evaluated within reversal designs for three children with autism spectrum disorder. In Experiment 1, we compared DR and NCR schedules that combined positive and negative reinforcement. In Experiment 2, we replicated the results of Experiment 1 and then evaluated NCR schedules composed solely of negative reinforcement and NCR schedules that combined negative reinforcement with high-or low-preferred stimuli. In Experiment 3, we further analyzed NCR schedules that included different types and qualities of positive reinforcement, but without the inclusion of negative reinforcement. The results showed that NCR schedules using positive reinforcers can be effective as a treatment for task disengagement, but the type and preference of the reinforcer can alter effectiveness. These results are interpreted in terms of the motivating operations associated with task disengagement.     

The effects of contingent music and differential reinforcement on infantile colic

Infantile Colic is a behavioral syndrome characterized by paroxysms of excessive crying and increased motor activity, hypertonicity of the musculature, excessive flatus and erratic sleeping and feeding patterns. Ten to 40% of all infants are diagnosed as having Colic. The medical evidence to date does not justify any conclusions regarding the etiology or treatment of Colic. Typically, parents are advised to simply wait until Colic has run its course which is often 3-4 months. The behavioral program reported here was designed to increase behavior that competed with crying by reinforcing quiet alertness with music and parental attention. Concurrently, it attempted to inhibit excessive crying by a brief time-out procedure. A group of 8 infants diagnosed as Infant Colic were included in this study. The dependent variable, crying, was measured through direct observations based on hourly samples involving 30 observations of 2-min intervals. The independent variable consisted of a behavioral treatment package. A within-S reversal design was used to assess the functional properties of the treatment. The results show that across all 8 infants the introduction of the treatment package led to a substantial decrease in excessive crying of about 75% of the initial baseline. Further, a functional relationship was identified between the treatment and excessive crying behavior: crying decreased when the treatment was initially introduced, it resumed when the treatment was withdrawn and decreased again when the treatment was reinstated.     

Self-instruction: An analysis of the differential effects of instruction and reinforcement

This study investigated the impact of training 9 first- and second-grade children to use a full self-instructional regimen, and then differentially reinforced the use of self-instruction only, accuracy only, or both self-instruction and accuracy. Three comparison children received no training in self-instruction and were reinforced for accuracy only. Children improved dramatically in academic accuracy subsequent to self-instructional training, independent of the use of self-instruction and of the specific behavior consequated. Children who were reinforced for using self-instruction did use self-instruction, and those who were not, did not. Comparison group children showed little improvement until training in problem-solving strategies was given after 9 days of reinforcement for accuracy. Self-instructional training is discussed as one type of event that increases the likelihood of accurate performance. Its effectiveness may be explained in terms of a teaching strategy rather than in terms of modifying cognitive processes.     

Differential reinforcement of low rates performance by impulsive and reflective children

Third-grade boys classified as either cognitively impulsive or reflective were reinforced for key pressing according to a DRL (differential reinforcement of low rates) 6-sec schedule of reinforcement. Half of each group received instructions about the behavioral requirements for obtaining reinforcements. Prior to DRL training, impulsive Ss showed a low probability of key press responding at long interresponse time (IRT) intervals while reflective Ss exhibited an equal probability of terminating either short or long IRTs. During training and in the absence of instructions, impulsives exhibited a less precise temporal discrimination, characterized by a greater predominance of response bursts (0–2 sec IRTs) following reinforcements, than reflective Ss. While impulsive and reflective Ss displayed similar frequencies of collateral behavior between successively reinforced responses, impulsives engaged in the reinforced response more frequently and tended (p < .08) to obtain fewer reinforcements. Instructions served to enhance the DRL performance.