An analysis of programming DRL schedules in educational settings

Interval timing relative to response inhibition in the differential reinforcement of low-rate responding in normally developing young adults

With recent proposal suggesting the multifaceted nature of impulsivity, researchers have been intrigued by the question of whether the impulsive behaviour measured in the traditionally psychological paradigms is unitary. One such paradigm, the differential reinforcement of low-rate responding (DRL), has been used to assess response inhibition, but its underlying mechanism has still been debated. In present research, we examined and differentiated the effects of both response inhibition and interval timing on a multisession DRL-10 s (DRL-10 s) in a large sample of normally developing young adults, as well as with three other measures including the stop-signal reaction task (SSRT), time production task-10 s (TPT-10 s), and the Barrett impulsivity scale-11 (BIS-11). The results showed that behavioural changes existed in DRL. As the task sessions progressed, there was an increase in both reinforcement probability and peak time, but a decrease in burst responses. Most importantly, both principal component analysis and generalized multilevel modeling yielded consistent results that as the task progressed, there was an increasing involvement of the TPT in the late sessions of DRL. However, none of the effect of SSRT was found. In sum, the differential degrees of involvement of the timing process, relative to response inhibition, were observed in DRL.

Resource limitations: A taxonomy

Decision making within the context of resource limitations requires balancing the short-term benefits of obtaining a resource and the long-term consequences of depleting those resources. The present manuscript focuses on four types of tasks that share this tradeoff to develop a taxonomy that will encourage a deeper understanding of the psychological processes at play. The four types considered are foraging, common pool traps, deterioration traps, and a novel designation referred to as resource cliffs. All four will be shown to include two opposite processes - depletion of the resource and its replenishment over time. By considering the unique and shared features of these tasks, a taxonomy of features emerges that can be combined to not only create novel tasks but also to shift the research focus to task features rather than specific tasks. The paper closes with a consideration of current theoretical frameworks previously applied to one or more of these resource-limitation tasks as well as the promise of reinforcement learning as a unifying theory.

Temporal regulation of children with autism spectrum disorder exposed to a differential-reinforcement-of low-rates schedule

This study investigated temporal adjustment of children with autism spectrum disorder under a differential-reinforcement-of-low-rates (DRL) schedule. Sixteen participants, aged 3.2 to 7 years, were exposed to two conditions, DRL 5 s and DRL 20 s. Children participated in 7 sessions in each condition, except for 1 participant who attained the adjustment criteria in the DRL 5-s schedule. Temporal adjustment was measured with the proportion of reinforced interresponse times (IRTs) and the mean IRT. The operant response was a press on a touch screen and the reinforcers were cartoons. IQ and receptive language were measured prior to the DRL sessions. Results showed that the mean proportion of reinforced IRTs was slightly higher in the DRL 5-s schedule. The mean IRT was above the IRT requirement in both conditions. However, substantial individual variability was observed. Children with higher IQ and receptive language scores presented a greater proportion of reinforced IRTs in both conditions. Moreover, participants who adjusted their responses to the DRL 5-s schedule were more likely to adjust responding to the DRL 20-s schedule. This suggests that some children might be more sensitive to reinforcement contingencies than others. This study points at future research in the field of timing in children.

Reducing excessive questions in adults at adult-day training centers using differential-reinforcement-of-low rates

Differential-reinforcement-of-low rate (DRL) schedules are often used to reduce, not eliminate, behavior. We systematically replicated Austin and Bevan (2011) to determine whether the number of questions asked by two adults with intellectual disabilities working at adult-day-training centers could be reduced using a full-session DRL. The full-session DRL involved delivery of a reinforcer at the end of the day if the number of questions asked was less than a specified number during the entire session. Questions, up to a specified number, were also reinforced within-session. The full-session DRL reduced the number of questions asked by both participants and increased duration of task engagement for one participant.

The role of signals in two variations of differential-reinforcement-of-low-rate procedures

Differential-reinforcement-of-low-rate (DRL) schedules are used to decrease the overall rate of, but not eliminate, a target response. Two variations of DRL, spaced-responding and full-session, exist. Preliminary comparative analyses suggest that the two schedules function differently when unsignaled. We compared response rates under these two DRL variations with and without signals. In Experiment 1, five preschool students played a game in which points were earned under DRL schedules. In some sessions, a stimulus signaled when responses would be reinforced (S+) or not reinforced (S-). In others, only an S- was present. Signals (S+/S-) facilitated and maintained responding in both types of DRL schedules. In Experiment 2, we modified the signals with five different preschoolers. Instead of an S- only, we did not present any signals. Elimination and high variability of the target response were observed with the S- only and absence of S+/S-, respectively. Signaled DRL schedules are recommended for application.

Differential Reinforcement of Low Rate Schedules Reduce Severe Problem Behavior

Differential-reinforcement-of-low-rate (DRL) schedules are reinforcement contingencies designed to reduce response rates. A common variation of the DRL arrangement is known as full-session DRL ( f-DRL), in which a reinforcer is presented at the end of an interval if the response rate during that interval is below a predetermined criterion. Prior human operant research involving arbitrary mouse clicks has shown that the f-DRL is likely to reduce target responding to near zero rates. Similarly, applied research has shown that the f-DRL is likely to reduce minimally disruptive classroom behavior. There are, however, relatively few successful applications of the f-DRL to severe forms of problem behavior (e.g., self-injurious behavior). Thus, the purpose of this study was to examine the effects of f-DRL on the severe problem behavior of individuals with intellectual and developmental disabilities. For four participants, the f-DRL reduced severe problem behavior by clinically significant levels. Furthermore, results of a contingency strength analysis showed a strong negative contingency strength between target responding and reinforcer delivery for all participants.

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.

Response interruption and DRL for the reduction of rapid eating

We assessed the efficacy of several procedures for reducing the rate of eating responses during mealtime by three institutionalized mentally retarded clients. A time-based (15 s) response interruption procedure was implemented which resulted in little change in eating responses for 2 of 3 subjects. A spaced-responding DRL 15-s procedure resulted in decreases in eating responses to target levels only after a prompting procedure was added. Procedures were evaluated using a multiple baseline across subjects design with assessment of generalization to nontreated meals. A change in eating behavior during breakfast occurred only after direct training in the breakfast setting. Maintenance data were collected at 1- and 5-month follow-up periods.

Use of differential reinforcement of low rates of behavior to decrease repetitive speech in an autistic adolescent

A differential reinforcement of low rates of behavior (DRL) schedule was successful in reducing repetitive speech in an autistic adolescent. Over a period of 18 months, the rate of repetitions was gradually reduced from a mean of 4.7 to less than 0.3 repetitions per min. Tokens were awarded for maintaining rates of repetitive speech below each of nine successive criterion levels. A reversal phase in which the token economy was no longer in effect resulted in a return to baseline repetition rates. Subsequent reintroduction of the contingencies saw a return to previous low levels of responding which were maintained at a 6-month and 14-month follow-up.

Treatment of an assaultive, sensory-impaired adolescent through a multicomponent behavioral program

This project examined the effects of a multicomponent behavioral treatment program on assaultive behavior in a deaf, visually-impaired adolescent boy. Two types of assaultiveness were monitored: aggression towards adults and destruction of the physical environment. Intervention consisted of a token economy system, a response cost procedure, a "relaxation" technique, and skill training sessions. Through use of a multiple baseline across behaviors design, it was demonstrated that differentially reinforcing the absence of target behaviors on a weekly basis was the crucial ingredient in the treatment package. During a maintenance programming phase, the boy was gradually weaned off the token system. At 1- and 2-year follow-ups, no aggressive or destructive acts had occurred and the boy was showing improved communication and interpersonal skills.