A re‐examination of melioration and rational choice

We examined how people allocate choices between two alternatives when the payoff from each alternative varied as a function of the allocation of recent choices. On any one trial alternative A had a higher immediate payoff than alternative B, but across all trials B had a higher overall payoff than A. Rational choice theory requires that participants allocate all their responses to the alternative with the greatest overall payoff irrespective of which has the higher immediate payoff. Melioration, in contrast, proposes that participants are motivated to choose the alternative with the higher immediate payoff, irrespective of the consequences for future returns. We report four experiments in which we varied the nature of the payoffs. Participants exhibited self‐control consistent with rational choice theory when payoffs varied in magnitude, but exhibited impulsiveness consistent with melioration when the payoffs varied in probability. Finally, we show that impulsivity when payoffs varied in probability can be overcome following un‐reinforced practice. Copyright © 2002 John Wiley & Sons, Ltd.     

Process-specific slowing with advancing age: evidence derived from the analysis of sequential effects

In the current study we examined the generalized slowing hypothesis on the mechanisms underlying sequential effects in serial two-choice reaction time tasks. For young adults, sequential effects of conditions with a high and a low stimulus presentation rate respectively pointed to an automatic and an expectancy mechanism. Older adults' low presentation rate data corroborated the general slowing hypothesis for expectancy, whereas the high presentation rate results did not. The observation of a differential influence of age on the automatic and the expectancy mechanism poses a problem for notions assuming that higher level processes are more vulnerable to advancing age than lower level processes.     

Effects of reinforcer magnitude on responding under differential-reinforcement-of-low-rate schedules of rats and pigeons

Experiment I investigated the effects of reinforcer magnitude on differential-reinforcement-of-low-rate (DRL) schedule performance in three phases. In Phase 1, two groups of rats (n = 6 and 5) responded under a DRI. 72-s schedule with reinforcer magnitudes of either 30 or 300 microl of water. After acquisition, the water amounts were reversed for each rat. In Phase 2, the effects of the same reinforcer magnitudes on DRL 18-s schedule performance were examined across conditions. In Phase 3, each rat responded unider a DR1. 18-s schedule in which the water amotnts alternated between 30 and 300 microl daily. Throughout each phase of Experiment 1, the larger reinforcer magnitude resulted in higher response rates and lower reinforcement rates. The peak of the interresponse-time distributions was at a lower value tinder the larger reinforcer magnitude. In Experiment 2, 3 pigeons responded under a DRL 20-s schedule in which reinforcer magnitude (1-s or 6-s access to grain) varied iron session to session. Higher response rates and lower reinforcement rates occurred tinder the longer hopper duration. These results demonstrate that larger reinforcer magnitudes engender less efficient DRL schedule performance in both rats and pigeons, and when reinforcer magnitude was held constant between sessions or was varied daily. The present results are consistent with previous research demonstrating a decrease in efficiency as a function of increased reinforcer magnituide tinder procedures that require a period of time without a specified response. These findings also support the claim that DRI. schedule performance is not governed solely by a timing process.     

Discrete-trial training for autistic children when reward is delayed: a comparison of conditioned cue value and response marking

Three children with autism were taught to identify pictures of objects. Their speed of acquisition of receptive speech skills was compared across two conditions. In the cue-value condition, a compound audiovisual stimulus was presented after correct responses and again when a primary reinforcer was delivered after a 5-s delay; in the response-marking condition, a second stimulus was presented after both correct and incorrect responses, but not prior to the primary reinforcer. In both conditions primary reinforcement was delayed for 5 s. Although the children learned receptive speech skills in both conditions, acquisition was faster in the cue-value condition.     

Reinforcement magnitude and responding during treatment with differential reinforcement

Basic findings indicate that the amount or magnitude of reinforcement can influence free-operant responding prior to and during extinction. In this study, the relation between reinforcement magnitude and adaptive behavior was evaluated with 3 children as part of treatment with differential reinforcement. In the first experiment, a communicative response was shaped and maintained by the same reinforcer that was found to maintain problem behavior. Two reinforcement magnitudes (20-s or 60-s access to toys or escape from demands) were compared and found to be associated with similar levels of resistance to extinction. The relation between reinforcement magnitude and response maintenance was further evaluated in the second experiment by exposing the communicative response to 20-s or 300-s access to toys or escape. Results for 2 participants suggested that this factor may alter the duration of postreinforcement pauses.     

An evaluation of two differential reinforcement procedures with escape extinction to treat food refusal

Consumption of solids and liquids occurs as a chain of behaviors that may include accepting, swallowing, and retaining the food or drink. In the current investigation, we evaluated the relative effectiveness of differential reinforcement of the first behavior in the chain (acceptance) versus differential reinforcement for the terminal behavior in the chain (mouth clean). Three children who had been diagnosed with a feeding disorder participated. Acceptance remained at zero when differential reinforcement contingencies were implemented for acceptance or mouth clean. Acceptance and mouth clean increased for all 3 participants once escape extinction was added to the differential reinforcement procedures, independent of whether reinforcement was provided for acceptance or for mouth clean. Maintenance was observed in 2 children when escape extinction was removed from the treatment package. The mechanism by which consumption increased is discussed in relation to positive and negative reinforcement contingencies.     

The influence of therapist attention on self-injury during a tangible condition

This study investigated the effects of therapist attention on the self-injurious behavior (SIB) of a 6-year-old girl with developmental disabilities. After results of a functional analysis indicated that SIB was maintained by attention and tangible reinforcement, tangible conditions with and without contingent verbal attention were compared. Results suggested that the inclusion of verbal attention in a tangible condition may confound functional analysis outcomes for behavior that is maintained by attention.     

A method for identifying satiation versus extinction effects under noncontingent reinforcement schedules

We evaluated one method for determining whether response suppression under noncontingent reinforcement (NCR) is a function of satiation or extinction. Three individuals with developmental disabilities who engaged in self-injurious behavior (SIB) or aggression participated. Results of functional analyses indicated that their problem behavior was maintained by social-positive reinforcement. NCR procedures, individualized for each participant, were implemented in a multiple baseline across subjects design and were associated with decreases in all participants' problem behavior. Identification of the mechanism by which NCR produced these effects was based on examination of cumulative records showing response patterns during and immediately following each NCR session. Satiation during NCR should lead to a temporary increase in responding during the post-NCR (extinction) period due to a transition from the availability to the unavailability of reinforcement (satiation to deprivation). Alternatively, extinction during NCR should reveal no increase in responding during the extinction period because the contingency for the problem behavior would remain unchanged and the transition from satiation to deprivation conditions would be irrelevant. Results suggested that the operative mechanisms of NCR were idiosyncratic across the 3 participants and appeared to change during treatment for 1 of the participants.     

Designing interventions that include delayed reinforcement: implications of recent laboratory research

The search for robust and durable interventions in everyday situations typically involves the use of delayed reinforcers, sometimes delivered well after a target behavior occurs. Integrating the findings from laboratory research on delayed reinforcement can contribute to the design and analysis of those applied interventions. As illustrations, we examine articles from the Journal of the Experimental Analysis of Behavior that analyzed delayed reinforcement with respect to response allocation (A. M. Williams & Lattal, 1999), stimulus chaining (B. A. Williams, 1999), and self-control (Jackson & Hackenberg, 1996). These studies help to clarify the conditions under which delayed reinforcement (a) exercises control of behavior, (b) entails conditioned reinforcement, and (c) displaces the effects of immediate reinforcement. The research has applied implications, including the development of positive social behavior and teaching people to make adaptive choices. DESCRIPTORS: delayed reinforcement, response allocation, stimulus chains, self-control, integration of basic and applied research     

Noncontingent peer attention as treatment for disruptive classroom behavior

A functional analysis isolated peer attention as the primary maintaining variable for disruptive behavior displayed by a student with attention deficit hyperactivity disorder. Using a brief reversal design, noncontingent reinforcement was then shown to reduce disruptive behavior relative to the peer attention condition. Implications for assessing behavior disorders in mainstream school settings are discussed.