A comparison of token and tandem schedules of reinforcement on response patterns for adolescents with autism

Token schedules of reinforcement are ubiquitous in clinical settings, yet little research has thoroughly evaluated the effects of token schedules on responding in clinical settings. Basic research has shown token schedules of reinforcement produce lower response rates and larger pre‐ratio pauses compared to tandem schedules. The purpose of the current study was to determine whether the same effects are produced with adolescents with autism or related disorders. We examined response patterns under otherwise identical FR token and FR tandem schedules. Tokens suppressed responding for one participant only under high schedule values and for a second participant under common clinical schedule values; no difference in responding occurred between token and tandem schedules for two participants. These results support the systematic evaluation of token schedules of reinforcement in clinical settings. Additional applied research is needed on token schedules to further our understanding of the underlying mechanisms that contribute to the overall effectiveness of token economies.     

Second-order schedules of token reinforcement with pigeons: implications for unit price

Four pigeons were exposed to second-order schedules of token reinforcement, with stimulus lights serving as token reinforcers. Tokens were earned according to a fixed-ratio (token-production) schedule, with the opportunity to exchange tokens for food (exchange period) occurring after a fixed number had been produced (exchange-production ratio). The token-production and exchange-production ratios were manipulated systematically across conditions. Response rates varied inversely with the token-production ratio at each exchange-production ratio. Response rates also varied inversely with the exchange-production ratio at each token-production ratio, particularly at the higher token-production ratios. At higher token-production and exchange-production ratios, response rates increased in token-production segments closer to exchange periods and food. Some conditions were conducted in a closed economy, in which the pigeons earned all their daily ration of food within the session. Relative to comparable open-economy conditions, response rates in the closed economy were less affected by changes in token-production ratio, resulting in higher levels of food intake and body weight. Some of the results are consistent with the economic concept of unit price, a cost-benefit ratio comprised of responses per unit of food delivery, but most are well accounted for by a consideration of the number of responses required to produce exchange periods, without regard to the amount of reinforcement available during those exchange periods.     

An analysis of the value of token reinforcement using a multiple-schedule assessment

Token systems are widely used in clinical settings, necessitating the development of methods to evaluate the reinforcing value of these systems. In the current paper, we replicated the use of a multiple-schedule reinforcer assessment (MSA; Smaby, MacDonald, Ahearn, & Dube, 2007) to evaluate the components of a token economy system for 4 learners with autism. Token systems had reinforcing value similar to primary reinforcers for 2 of the 4 learners, but resulted in lower rates of responding than primary reinforcers for the other 2 learners. Differentiated responding across learners may warrant variation in clinical recommendations on the use of tokens. The results of this study support formal assessment of token system effectiveness, and the MSA procedure provides an efficient method by which to conduct such assessments.     

Second-order schedules of token reinforcement with pigeons: effects of fixed- and variable-ratio exchange schedules

Pigeons' key pecks produced food under second-order schedules of token reinforcement, with light-emitting diodes serving as token reinforcers. In Experiment 1, tokens were earned according to a fixed-ratio 50 schedule and were exchanged for food according to either fixed-ratio or variable-ratio exchange schedules, with schedule type varied across conditions. In Experiment 2, schedule type was varied within sessions using a multiple schedule. In one component, tokens were earned according to a fixed-ratio 50 schedule and exchanged according to a variable-ratio schedule. In the other component, tokens were earned according to a variable-ratio 50 schedule and exchanged according to a fixed-ratio schedule. In both experiments, the number of responses per exchange was varied parametrically across conditions, ranging from 50 to 400 responses. Response rates decreased systematically with increases in the fixed-ratio exchange schedules, but were much less affected by changes in the variable-ratio exchange schedules. Response rates were consistently higher under variable-ratio exchange schedules than tinder comparable fixed-ratio exchange schedules, especially at higher exchange ratios. These response-rate differences were due both to greater pre-ratio pausing and to lower local rates tinder the fixed-ratio exchange schedules. Local response rates increased with proximity to food under the higher fixed-ratio exchange schedules, indicative of discriminative control by the tokens.     

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.     

A study of misbehavior: token reinforcement in the rat

The purpose of this research was to investigate the phenomenon of misbehavior described by Breland and Breland (1961). Rats were trained to obtain ball-bearings and drop them in a hole for food or water reinforcers. In confirmation of the Brelands' observation, many subjects were slow to deliver the balls, and frequently attempted to chew them before they were dropped. A series of four experiments, in which the same rats were used throughout, showed that delivery times tended to be longer with food than with water, and that these times increased when nylon balls were substituted. The effect of motivational level was investigated by varying both deprivation and amount of prefeeding; no effect on delivery time was detected, although other measures of performance were affected by motivational factors. Similar results were obtained in a final experiment that employed a new set of naive subjects. The studies demonstrated that misbehavior can be studied in an experimental situation, and the results supported an analysis in terms of competition between stimulus-reinforcer and response-reinforcer contingencies. The question of why such effects have not been reported in previous token reinforcer studies was unanswered.     

Assessing the value of choice in a token system

Responding of 4 children was assessed under conditions in which (a) no programmed contingencies were arranged for target behavior, (b) responding produced tokens that could be exchanged for a single highly preferred edible item, and (c) responding produced a token that could be exchanged for a variety of preferred edible items. After assessing the effects of these contingencies, the preferences of 3 participants were assessed using a concurrent-chains schedule. Preference for the opportunity to choose from the same or qualitatively different edible items varied across participants, and findings were generally consistent with those of Tiger, Hanley, and Hernandez (2006).     

Second-order schedules of token reinforcement: comparisons of performance under fixed-ratio and variable-ratio exchange schedules

Rats' lever pressing produced tokens according to a 20-response fixed-ratio schedule. Sequences of token schedules were reinforced under a second-order schedule by presentation of periods when tokens could be exchanged for food pellets. When the exchange period schedule was a six-response fixed ratio, patterns of completing the component token schedules were bivalued, with relatively long and frequent pauses marking the initiation of each new sequence. Altering the exchange period schedule to a six-response variable ratio resulted in sharp reductions in the frequency and duration of these initial pauses, and increases in overall rates of lever pressing. These results are comparable to those ordinarily obtained under simple fixed-ratio and variable-ratio schedules.     

Incentivizing physical activity using token reinforcement with preschool children

We combined several single‐subject designs to assess the effects of contingent and noncontingent token reinforcement on moderate‐to‐vigorous physical activity (MVPA) exhibited by 4 preschool‐aged children. Higher overall levels and longer bouts of MVPA reliably occurred when tokens were delivered contingent on MVPA for 3 of the 4 children when compared to baseline (no token) and for 2 of the 4 children when compared to noncontingent‐token conditions. The present study demonstrated that the delivery of tokens contingent on MVPA can increase and maintain MVPA exhibited by preschool‐aged children, resulting in more MVPA than in baseline conditions and conditions in which tokens are awarded without respect to MVPA. These results demonstrate that token economies can be used to increase MVPA and they add to the evidence base supporting the use of token economies to address a range of behavior problems.     

Efficacy of and preference for reinforcement and response cost in token economies

Researchers have shown that both differential reinforcement and response cost within token economies are similarly effective for changing the behavior of individuals in a group context (e.g., Donaldson, DeLeon, Fisher, & Kahng, 2014; Iwata & Bailey, 1974). In addition, these researchers have empirically evaluated preference for these procedures. However, few previous studies have evaluated the individual effects of these procedures both in group contexts and in the absence of peers. Therefore, we replicated and extended previous research by determining the individual effects and preferences of differential reinforcement and response cost under both group and individualized conditions. Results demonstrated that the procedures were equally effective for increasing on‐task behavior during group and individual instruction for most children, and preference varied across participants. In addition, results were consistent across participants who experienced the procedures in group and individualized settings.     

Assessing reinforcers under progressive schedule requirements.

Recent research findings suggest that reinforcing stimuli may be differentially effective as response requirements increase. We extended this line of research by evaluating responding under increasing schedule requirements via progressive‐ratio schedules and behavioral economic analyses. The differential effectiveness of preferred stimuli in treating destructive behavior maintained by automatic reinforcement also was examined. Results showed that one of two stimuli was associated with more responding under increasing schedule requirements for the 4 participants. Furthermore, stimuli associated with more responding under increasing schedule requirements generally were more effective in treating destructive behavior than stimuli associated with less responding. These data suggest that progressive‐ratio schedules and behavioral economic analyses may be useful for developing a new technology for reinforcer identification. From a clinical perspective, these results suggest that two reinforcers may be similarly effective for low‐effort tasks and differentially effective for high‐effort tasks.     

The effects of differential and lag reinforcement schedules on varied verbal responding by individuals with autism

Variability has been shown to be a reinforceable dimension of behavior. One procedure that has been demonstrated to increase variability in basic research is the lag reinforcement schedule. On this type of schedule, a response is reinforced if it differs from a specified number of previous responses. Lag schedules are rarely used, however, for increasing response variability in applied settings. The purpose of the present study was to investigate the effects of a lag schedule of differential reinforcement on varied and appropriate verbal responding to social questions by 3 males with autism. A reversal design with a multiple baseline across subjects was used to evaluate the effects of the lag schedule. During baseline, differential reinforcement of appropriate responding (DRA) resulted in little or no varied responding. During the intervention, a Lag 1 requirement was added to the DRA (Lag 1/DRA) resulting in an increase in the percentage of trials with varied and appropriate verbal responding for 2 of the 3 participants. In addition, an increase in the cumulative number of novel verbal responses was also observed for the same 2 participants. These results are discussed in terms of reinforcement schedules that support variability, generalization, and potential stimulus control over varied responding.     

Using token reinforcement to increase walking for adults with intellectual disabilities

The purpose of this study was to evaluate the effectiveness of token reinforcement, using an ABAB reversal design, for increasing distance walked for adults with mild to moderate intellectual disabilities at an adult day‐training center. Five participants earned tokens for walking 50‐m laps and exchanged tokens for back‐up reinforcers that had been identified through preference assessments. Token reinforcement resulted in a substantial increase from baseline in laps walked for 4 participants.     

Substitution effects in a generalized token economy with pigeons

Pigeons made repeated choices between earning and exchanging reinforcer‐specific tokens (green tokens exchangeable for food, red tokens exchangeable for water) and reinforcer‐general tokens (white tokens exchangeable for food or water) in a closed token economy. Food and green food tokens could be earned on one panel; water and red water tokens could be earned on a second panel; white generalized tokens could be earned on either panel. Responses on one key produced tokens according to a fixed‐ratio schedule, whereas responses on a second key produced exchange periods, during which all previously earned tokens could be exchanged for the appropriate commodity. Most conditions were conducted in a closed economy, and pigeons distributed their token allocation in ways that permitted food and water consumption. When the price of all tokens was equal and low, most pigeons preferred the generalized tokens. When token‐production prices were manipulated, pigeons reduced production of the tokens that increased in price while increasing production of the generalized tokens that remained at a fixed price. The latter is consistent with a substitution effect: Generalized tokens increased and were exchanged for the more expensive reinforcer. When food and water were made freely available outside the session, token production and exchange was sharply reduced but was not eliminated, even in conditions when it no longer produced tokens. The results join with other recent data in showing sustained generalized functions of token reinforcers, and demonstrate the utility of token‐economic methods for assessing demand for and substitution among multiple commodities in a laboratory context.     

An assessment of differential reinforcement procedures for learners with autism spectrum disorder

Differential reinforcement procedures may promote unprompted correct responding, resulting in a quicker transfer of stimulus control than nondifferential reinforcement. Recent studies that have compared reinforcement arrangements have found that the most effective arrangement may differ across participants. The current study conducted an assessment of differential reinforcement arrangements (i.e., quality, schedule, and magnitude) and nondifferential reinforcement to identify the most effective arrangement for each participant. The assessment phase showed that the quality arrangement was the most efficient for all participants during auditory‐visual matching. Next, a validation phase was conducted to evaluate whether the assessment would predict the most effective arrangement across multiple skills. The results from the assessment phase were validated for all participants for the same skill. However, the results were only validated for one participant during the other skills (i.e., tact and intraverbal). The results are discussed in light of previous research and future areas of research.     

Exchange schedules in token economies: A preliminary investigation of second‐order schedule effects

Basic research shows that token‐production and exchange‐production schedules in token economies affect each other as second‐order schedules (i.e., the exchange‐production schedule's requirements affect responding toward the token‐production schedule). This relationship has not been investigated with children in academic settings despite the widespread use of token economies in this context. This study compared the effects of fixed‐ratio (FR) and variable‐ratio (VR) exchange‐production schedules of equal ratios (2, 5, and 10) on responding toward an FR 1 token‐production schedule with a child diagnosed with autism. A concurrent chains assessment was also conducted to assess the participant's relative preference for FR and VR exchange‐production schedule arrangements within her typical discrete trial training. Results showed no difference in response rate between the two schedule types. However, the concurrent chains assessment revealed an exclusive preference for the VR arrangement.     

Preference for reinforcers under progressive- and fixed-ratio schedules: a comparison of single and concurrent arrangements

Progressive-ratio (PR) schedules were used to identify the break point (i.e., the last schedule value completed) for 2 reinforcers under single and concurrent schedules. After the respective break points were established, the same reinforcers were presented under concurrent fixed-ratio (FR) schedules that were yoked to the break points obtained with the PR schedules. Results suggested that the participants responded more for the high-preference item than for the low-preference item, regardless of the presentation arrangement (single or concurrent presentations). This pattern of responding was maintained when the reinforcers were presented under dissimilar FR schedules. The results suggest that responding for differentially preferred stimuli may vary as a function of differences in schedule requirements.