Rapid acquisition of preference in concurrent chains

We report two experiments using a concurrent-chains procedure in which one terminal-link schedule was fixed-interval 8 s and the alternative schedule changed randomly from day to day. In Experiment 1, the alternative schedule varied between 4 s and 16 s according to a pseudorandom binary sequence similar to the one used by Hunter and Davison (1985). Similar to results with concurrent schedules, pigeons' response allocation in the initial link was most sensitive to the schedules arranged in the current session, although some effect of prior history was evident. Overall sensitivity was lower than for comparable data from steady-state research. In Experiment 2, a unique value between 2 s and 32 s was used for the alternative-schedule delay in each session. Sensitivity levels were similar to Experiment 1 and remained unchanged across 61 sessions of training. For all subjects, sensitivity was greater when the alternative-schedule delay was greater than 8 s compared with when it was less than 8 s. Generalized-matching plots revealed evidence of clustering of data points into two groups for some pigeons, suggesting that a process similar to a categorical discrimination may have at least partly determined response allocation. Overall, this research shows that pigeons' initial-link response allocation can adjust rapidly to frequent changes in the terminal links.     

Stimulus generalization of behavioral history

Undergraduates responded under a variable-ratio 30 schedule in the presence of a 25-mm long line and on a differential-reinforcement-of-low-rate 6-s schedule when a 13-mm long line was present. Following this, a line-length continuum generalization test was administered under a fixed-interval 6-s schedule (Experiment 1) or extinction (Experiment 2). In both experiments, obtained generalization gradients conformed to typical postdiscrimination gradients. Responses were frequent under stimuli physically similar to the 25-mm line and infrequent under stimuli physically similar to the 13-mm line. The generalization gradients were generally asymmetric with peak response rates occurring at line lengths greater than 25 mm.     

Preference reversals with food and water reinforcers in rats

Rats were given a choice between a smaller, immediately available reward and a larger reward available after a delay. In one phase, the reward was food and in another phase, the reward was water. Constant delays were added between the choice presentation and the delivery of the reward alternatives. As the time between choice and reward delivery increased from 0 to 25 s, all rats (except one in the water phase) reversed their preference from the smaller, sooner alternative to the larger, later alternative. These findings extend the generality of the preference-reversal animal model to qualitatively different reinforcers. Furthermore, the presence of both impulsive and self-control choices within the same animal is consistent with the view that self-control may be understood as choice behavior, and that species differences in self-control may be differences in degree, not kind.     

Response acquisition under direct and indirect contingencies of reinforcement

We compared the effects of direct and indirect reinforcement contingencies on the performance of 6 individuals with profound developmental disabilities. Under both contingencies, completion of identical tasks (opening one of several types of containers) produced access to identical reinforcers. Under the direct contingency, the reinforcer was placed inside the container to be opened; under the indirect contingency, the therapist held the reinforcer and delivered it to the participant upon task completion. One participant immediately performed the task at 100% accuracy under both contingencies. Three participants showed either more immediate or larger improvements in performance under the direct contingency. The remaining 2 participants showed improved performance only under the direct reinforcement contingency. Data taken on the occurrence of "irrelevant" behaviors under the indirect contingency (e.g., reaching for the reinforcer instead of performing the task) provided some evidence that these behaviors may have interfered with task performance and that their occurrence was a function of differential stimulus control.     

An evaluation of the effects of matched stimuli on behaviors maintained by automatic reinforcement

The purpose of the current investigation was to extend the literature on matched stimuli to three dissimilar forms of aberrant behavior (dangerous climbing and jumping, saliva manipulation, and hand mouthing). The results of functional analyses suggested that each behavior was automatically reinforced. Preference assessments were used to identify two classes of stimuli: items that matched the hypothesized sensory consequences of aberrant behavior (matched stimuli) and items that produced sensory consequences that were not similar to those produced by the aberrant behavior (unmatched stimuli). The effects of providing continuous and noncontingent access to either the most highly preferred matched or the most highly preferred unmatched stimuli were assessed relative to a condition in which no stimuli were available. Overall results suggested that providing access to items that matched the hypothesized sensory consequences of aberrant behavior may be more effective than simply selecting stimuli either arbitrarily or based on the results of preference assessments alone.     

Integrating basic and applied research and the utility of Lattal and Perone's Handbook of research methods in human operant behavior

Lattal and Perone's Handbook of methods used in human operant research on behavioral processes will be a valuable resource for researchers who want to bridge laboratory developments with applied study. As a supplemental resource, investigators are also encouraged to examine the series of papers in the Journal of Applied Behavior Analysis that discuss basic research and its potential for application. Increased knowledge of behavioral processes in laboratory research could lead to innovative solutions to practical problems addressed by applied behavior analysts in the home, classroom, clinic, and community.     

Effects of choice of stimuli as reinforcement for task responding in reinforcement for task responding in preschoolers with and without developmental disabilities

The effects of choice and no choice of stimuli as reinforcement for task responding were investigated across preschoolers with and without disabilities. Five less preferred stimuli were identified for each participant using a stimulus preference assessment. No differences were found for choice and no-choice conditions when the less preferred stimuli were used as reinforcers.     

A component analysis of "stereotypy as reinforcement" for alternative behavior

Results from several studies have suggested that the opportunity to engage in stereotypic behavior may function as reinforcement for alternative, more socially desirable behaviors. However, the procedural components of this intervention include several distinct operations whose effects have not been analyzed separately. While measuring the occurrence of stereotypy and an alternative behavior (manipulation of leisure materials), we exposed 3 participants to three or four components of a "stereotypy as reinforcement" contingency: (a) continuous access to materials, (b) prompts to manipulate materials, (c) restricted access to stereotypy (i.e., response blocking), and (d) access to stereotypy contingent on manipulating the materials. Continuous access to materials and prompting (a and b) produced negligible results. Restriction of stereotypy (c) produced a large increase in the alternative behavior of 2 participants, suggesting that response restriction per se may occasion alternative behavior. However, contingent access to stereotypy (d) was necessary to increase the 3rd participant's object manipulation; this finding provided some support for the use of stereotypy as reinforcement for alternative behavior. Finally, when transfer of the effects of intervention was assessed during periods in which active intervention components were withdrawn, the alternative behavior was maintained for 1 participant.     

Functional equivalence classes in rats: Repeated olfactory discrimination reversals and delayed stimulus probes

The simultaneous matching-to-sample procedures that are widely used to study stimulus equivalence in human participants have generally been unsuccessful in animals. However, functional equivalence classes have been demonstrated in pigeons and sea lions using a concurrent repeated reversal discrimination procedure. In this procedure, responding to one set of stimuli is reinforced but responding to a different set is not and the set associated with reinforcement is changed with multiple reversals during the experiment. The experiments reported here were designed to assess whether functional equivalence classes could be demonstrated in rats using similar techniques. Rats were initially trained with two sets of olfactory stimuli (six odors/set). Following many reversals, probe reversal sessions were conducted in which rats were exposed to a subset of the members of each set and, later in the session, the withheld stimuli were introduced. Responding to these delayed probe trials in accord with the reversed contingencies constituted transfer of function. There was some evidence of transfer in Experiment 1, but the effects were relatively weak and variable. Experiment 2 introduced procedural changes and found strong evidence of transfer of function consistent with the formation of functional equivalence classes. These procedures offer a promising strategy to study symbolic behavior in rodents.     

Effects of video self-modeling on the preference and reinforcer value of toys for children diagnosed with autism spectrum disorder

A primary characteristic of autism spectrum disorder includes restrictive and repetitive patterns of behavior. Because having few preferred items and activities can lead to social, communicative, and educational barriers, it is important to increase the number of preferred stimuli in the individual's environment. One way to do this is through conditioned reinforcement via observation. Such procedures involve the acquisition of a skill or change in behavior as a result of indirect contact (i.e., observation) with contingencies received by others. While conditioning through observation has been shown to be effective, one novel approach is video self-modeling. The purpose of the current study was to assess the effects of video self-modeling on the preference and reinforcer value of toys for children diagnosed with autism spectrum disorder.