Effects of self-control training for elementary students with emotional and behavioral disorders

Progressive delay training (PDT) has been used to promote self-controlled choices (i.e., selecting a larger, later reward over a smaller, immediate reward) for people with a variety of developmental characteristics. However, the efficacy of PDT has not been evaluated in children with emotional and behavioral disorders (EBD), who often have co-occurring symptoms of impulsivity. The purpose of this study was to evaluate the effects of PDT with a rule-following requirement on the impulsive choices of 6 elementary students with EBD using a modified changing criterion design. Results indicated that PDT alone did not improve self-control, but a modified version of PDT with a rationale and rule for selecting the delayed reward promoted self-control for 3 participants. The remaining 3 participants continued to make impulsive choices despite further modifications to the PDT protocol. We discuss implications of our results and directions for future research on treating impulsivity in children with EBD.     

All Behavior is choice: Revisiting an evolutionary theory's account of behavior on single schedules

The axiomatic principle that all behavior is choice was incorporated into a revised implementation of an evolutionary theory's account of behavior on single schedules. According to this implementation, target responding occurs in the context of background responding and reinforcement. In Phase 1 of the research, the target responding of artificial organisms (AOs) animated by the revised theory was found to be well described by an exponentiated hyperbola, the parameters of which varied as a function of the background reinforcement rate. In Phase 2, the effect of reinforcer magnitude on the target behavior of the AOs was studied. As in Phase 1, the AOs' behavior was well described by an exponentiated hyperbola, the parameters of which varied with both the target reinforcer magnitude and the background reinforcement rate. Evidence from experiments with live organisms was found to be consistent with the Phase-1 predictions of the revised theory. The Phase-2 predictions have not been tested. The revised implementation of the theory can be used to study the effects of superimposing punishment on single-schedule responding, and it may lead to the discovery of a function that relates response rate to both the rate and magnitude of reinforcement on single schedules.     

A preliminary analysis of self-control with aversive events: the effects of task magnitude and delay on the choices of children with autism

When faced with a choice between two aversive events, a person exhibits self-control by choosing a smaller, more immediate aversive event over a larger, delayed aversive event. Task demands are often aversive to children with autism and other developmental disabilities. The purpose of this study was to evaluate behavioral sensitivity to differences in the amount and delay of tasks as part of a preliminary study on self-control. Participants were 2 children with autism who engaged in problem behavior maintained by escape. Results indicated a lack of self-control with respect to choosing between two aversive tasks and suggested potential strategies for increasing self-control (i.e., choosing a small immediate task over a large delayed task).     

Replacing relative reinforcing efficacy with behavioral economic demand curves

Relative reinforcing efficacy refers to the behavior-strengthening or maintaining property of a reinforcer when compared to that of another reinforcer. Traditional measures of relative reinforcing efficacy sometimes have led to discordant results across and within studies. By contrast, previous investigations have found traditional measures to be congruent with behavioral economic measures, which provide a framework for integrating the discordant results. This study tested whether the previously demonstrated congruence between traditional relative reinforcing efficacy measures and behavioral economic demand curve measures is sufficiently robust to persist when demand for one reinforcer is altered. Cigarette smokers pulled plungers for cigarettes or two magnitudes of money on progressive-ratio schedules that increased the response requirement across sessions. Demand for the two different reinforcers was assessed in single-schedule and concurrent-schedule sessions. Demand curve measures Pmax and Omax correlated significantly with traditional measures of breakpoint and peak response rate, respectively. Relative locations of demand curves for money and cigarettes under single schedules predicted preference in concurrent schedules in most cases. Although measures of relative reinforcing efficacy for money changed with money magnitude, the congruence between traditional and behavioral economic measures remained intact. This robust congruence supports the proposal that demand curves should replace measures of relative reinforcing efficacy. The demand curve analysis illustrates why concordance between traditional measures is expected under some experimental conditions but not others.     

Effects of signaled versus unsignaled delay of reinforcement on choice

Pigeons chose between 5-s and 15-s delay-of-reinforcement alternatives. The first key peck to satisfy the choice schedule began a delay timer, and food was delivered at the end of the interval. Key pecks during the delay interval were measured, but had no scheduled effect. In Experiment 1, signal conditions and choice schedules were varied across conditions. During unsignaled conditions, no stimulus change signaled the beginning of a delay interval. During differential and nondifferential signal conditions, offset of the choice stimuli and onset of a delay stimulus signaled the beginning of a delay interval. During differential signal conditions, different stimuli were correlated with the 5-s and 15-s delays, whereas the same stimulus appeared during both delay durations during nondifferential signal conditions. Pigeons showed similar, extreme levels of preference for the 5-s delay alternative during unsignaled and differentially signaled conditions. Preference levels were reliably lower with nondifferential signals. Experiment 2 assessed preference with two pairs of unsignaled delays in which the ratio of delays was held constant but the absolute duration was increased fourfold. No effect of absolute duration was found. The results highlight the importance of delayed primary reinforcement effects and challenge models of choice that focus solely on conditioned reinforcement.     

A brief computer-based assessment of reinforcer dimensions affecting choice

In an extension of Neef, Shade, and Miller (1994), we used a brief computer-based assessment of differential responsiveness to reinforcer rate, quality, delay, and response effort in affecting the choices of 11 participants. The assessment involved successive presentations of two concurrent sets of math problems, each set associated with competing reinforcer or response dimensions in a counterbalanced fashion. The results showed that the reinforcer and response dimensions differentially affected choice, with time-allocation patterns varying across students.     

Assessment of impulsivity and the development of self-control in students with attention deficit hyperactivity disorder.

We examined a combined approach of manipulating reinforcer dimensions and delay fading to promote the development of self‐control with 3 students diagnosed with attention deficit hyperactivity disorder. First, we administered a brief computer‐based assessment to determine the relative influence of reinforcer rate (R), reinforcer quality (Q), reinforcer immediacy (I), and effort (E) on the students' choices between concurrently presented math problems. During each session, one of these dimensions was placed in direct competition with another dimension (e.g., RvI involving math problem alternatives associated with high‐rate delayed reinforcement vs. low‐rate immediate reinforcement), with all possible pairs of dimensions presented across the six assessment conditions (RvQ, RvI, RvE, QvI, QvE, IvE). The assessment revealed that the choices of all 3 students were most influenced by immediacy of reinforcement, reflecting impulsivity. We then implemented a self‐control training procedure in which reinforcer immediacy competed with another influential dimension (RvI or QvI), and the delay associated with the higher rate or quality reinforcer alternative was progressively increased. The students allocated the majority of their time to the math problem alternatives yielding more frequent (high‐rate) or preferred (high‐quality) reinforcement despite delays of up to 24 hr. Subsequent readministration of portions of the assessment showed that self‐control transferred across untrained dimensions of reinforcement.     

DO ADJUSTING‐AMOUNT AND ADJUSTING‐DELAY PROCEDURES PRODUCE EQUIVALENT ESTIMATES OF SUBJECTIVE VALUE IN PIGEONS?

The current experiment examined whether adjusting-amount and adjusting-delay procedures provide equivalent measures of discounting. Pigeons' discounting on the two procedures was compared using a within-subject yoking technique in which the indifference point (number of pellets or time until reinforcement) obtained with one procedure determined the value of the corresponding variable in the yoked condition with the other procedure. Behavior on each procedure was well described by a hyperbolic discounting function. Results revealed no systematic differences in the degree of discounting as measured by the discounting rate parameter of the hyperbola in Experiment 1, which used 20-mg pellets. These results were replicated in Experiment 2 using smaller, 14-mg pellets, which potentially yield more precise measurement of indifference points on the adjusting-amount procedure. The finding that estimates of the k parameter in the hyperbolic discounting function obtained with one procedure did not differ systematically from estimates obtained from the same subjects with the other procedure represents strong support for the hypothesis that the same process underlies the discounting of delayed rewards on both adjusting-amount and adjusting-delay procedures.     

Contingency tracking during unsignaled delayed reinforcement

Three experiments were conducted with rats in which responses on one lever (labeled the functional lever) produced reinforcers after an unsignaled delay period that reset with each response during the delay. Responses on a second, nonfunctional, lever did not initiate delays, but, in the first and third experiments, such responses during the last 10 s of a delay did postpone food delivery another 10 s. In the first experiment, the location of the two levers was reversed several times. Responding generally was higher on the functional lever, though the magnitude of the difference diminished with successive reversals. In the second experiment, once a delay was initiated by a response on the functional lever, in different conditions responses on the nonfunctional lever either had no effect or postponed food delivery by 30 s. The latter contingency typically lowered response rates on the nonfunctional lever. In the first two experiments, both the functional and nonfunctional levers were identical except for their location; in the third experiment, initially, a vertically mounted, pole-push lever defined the functional response and a horizontally mounted lever defined the nonfunctional response. Higher response rates occurred on the functional lever. These results taken together suggest that responding generally tracked the response-reinforcer contingency. The results further show how nonfunctional-operanda responses are controlled by a prior history of direct reinforcement of such responses, by the temporal delay between such responses and food delivery, and as simple generalization between the two operanda.     

Failure to replicate the 'work ethic" effect in pigeons

We report six unsuccessful attempts to replicate the "work ethic" phenomenon reported by Clement, Feltus, Kaiser, and Zentall (2000). In Experiments 1-5, pigeons learned two simultaneous discriminations in which the S+ and S- stimuli were obtained by pecking an initial stimulus once or multiple (20 or 40) times. Subsequent preference tests between the S+ stimuli and between the S- stimuli mostly revealed indifference, on average, between the S+ from the multiple-peck (high-effort) trials and the S+ from the one-peck (low-effort) trials, and likewise between the two respective Sstimuli. Using a slightly different procedure that permitted assessment of the relative aversiveness of low versus high effort, Experiment 6 again revealed a pattern of indifference despite showing that pigeons took considerably longer to begin pecking on high- than on low-effort trials. Our findings call into question the reliability of the original findings and the sufficiency of the hypothesized within-trial contrast mechanism to produce them.