TRAINING STUDENTS WITH PROFOUND OR MULTIPLE HANDICAPS TO MAKE REQUESTS VIA MICROSWITCHES

In a series of three experiments, we evaluated the use of microswitches as a means for students with profound, multiple handicaps to demonstrate preferences between toys and to make requests for specific activities. In Experiment 1, 5 students learned to demonstrate toy preferences by using microswitches to activate battery-operated toys. Experiment 2 was conducted to evaluate the students' preferences for social attention. Microswitches were used to activate prerecorded messages that signaled the classroom teacher to attend to the students. In Experiment 3, the students used the switches and prerecorded messages to make specific requests of educational staff in school and community settings. Results of these experiments, evaluated within multiple baseline, alternating treatments, and simultaneous treatments designs, indicated that these students could request specific activities. Results are discussed with respect to the continued use of microswitches and to program development.     

Computer‐assisted learning for adults with profound multiple disabilities

Five adults with profound physical and intellectual disabilities were taught to respond to photographs of preferences embedded in Microsoft PowerPoint (Microsoft, 1997 ) presentations by operating microswitches that functioned as mouse clicks. Rate of responding was generally correlated with changes in types of presentation, although variability in rate was often high, and session durations were quite short. Two participants showed substantial increases in responding when fitted with switches that were easier to manipulate. This exploratory study demonstrates that people with extremely limited physical and cognitive abilities can be taught to operate switches that produce changes in visual arrays on a computer screen and sometimes differentially so. Implications for responding to photographic representations of preferences, rather than the tangible preferences themselves, are discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

Stimulus–reinforcer relations established during training determine resistance to extinction and relapse via reinstatement

The baseline rate of a reinforced target response decreases with the availability of response‐independent sources of alternative reinforcement; however, resistance to disruption and relapse increases. Because many behavioral treatments for problem behavior include response‐dependent reinforcement of alternative behavior, the present study assessed whether response‐dependent alternative reinforcement also decreases baseline response rates but increases resistance to extinction and relapse. We reinforced target responding at equal rates across two components of a multiple schedule with pigeons. We compared resistance to extinction and relapse via reinstatement of (1) a target response trained concurrently with a reinforced alternative response in one component with (2) a target response trained either concurrently or in separate components from the alternative response across conditions. Target response rates trained alone in baseline were higher but resistance to extinction and relapse via reinstatement tests were greater after training concurrently with the alternative response. In another assessment, training target and alternative responding together, but separating them during extinction and reinstatement tests, produced equal resistance to extinction and relapse. Together, these findings are consistent with behavioral momentum theory—operant response–reinforcer relations determined baseline response rates but Pavlovian stimulus–reinforcer relations established during training determined resistance to extinction and relapse. These findings imply that reinforcing alternative behavior to treat problem behavior could initially reduce rates but increase persistence.     

A PRACTICAL STRATEGY FOR ONGOING REINFORCER ASSESSMENT

There is a need for practical methods of reinforcer assessment that systematically track ongoing changes in clients' preferences. In this study, the effects of a time-efficient reinforcer assessment package were evaluated in a multiple baseline across 3 preschoolers with autism, comparing individualized item selections by experienced teachers with children's presession preferences for items of various sensory qualities. Systematic assessment of children's reinforcers for correct responding virtually eliminated nontargeted maladaptive behaviors, as well as yielding expected improvements in accuracy. The powerful side-effects of potent reinforcers underline the importance of increased attention to reinforcer assessment in research and practice.     

Some effects of response-correlated increases in reinforcer magnitude on human behavior

After training under short or long fixed-interval schedules, humans responded under a modified fixed-interval schedule in which magnitude of reinforcement (X or 2X) was minimally correlated with response frequency. Response frequencies that equaled or exceeded a minimum response criterion were followed by the larger reinforcer at the end of the interval; otherwise, the smaller reinforcer was delivered. The modified schedule alternated with the baseline schedule across conditions. In a control condition, the reinforcer magnitudes produced by control subjects were yoked to those of experimental subjects. Experimental subjects, but not control subjects, showed increased responding. In addition to the baseline and modified fixed-interval schedules used in Experiment 1, subjects in Experiment 2 also responded under a second modified fixed-interval contingency in which increases in reinforcer magnitude were more highly correlated with response frequency. Experimental subjects, but not control subjects, showed increased responding under both procedures. Direct comparison of these two procedures showed that the high-correlation procedure produced greater increases in responding than did the low-correlation procedure.     

Interactions between conditioned stimuli for food and water in the rat

In two experiments rats were initially trained with one conditioned stimulus (CS) signalling food and another CS signalling water. The main purpose of the experiments was to examine the effects of presenting these stimuli in compound. Experiment 1 demonstrated that the level of conditioned responding to this compound was equal to that of a group for which the compound was composed of elements that had separately signalled the same reinforcer. Moreover, the level of this responding was greater than for a group that had received only compound conditioning. In the second experiment it was found that after the initial training, repeatedly pairing the compound with a single reinforcer resulted in an equivalent loss of conditioned responding to both elements. These findings suggest that the interaction between conditioned stimuli for food and water is facilitatory rather than inhibitory.     

Relations between Pavlovian-instrumental transfer and reinforcer devaluation

Relations between posttraining reinforcer devaluation and Pavlovian-instrumental transfer were examined in 2 experiments. When a single reinforcer was used, extended training of the instrumental response increased transfer but reduced devaluation effects. When multiple instrumental reinforcers were used, both reinforcer-specific transfer and devaluation effects were less influenced by the amount of instrumental training. Finally, although reinforcer devaluation decreased both Pavlovian conditioned responses and baseline instrumental responding, it had no effect on either single-reinforcer or reinforcer-specific transfer. These results indicate that transfer and reinforcer devaluation can reflect different aspects of associative learning and that the nature of associative learning can be influenced by parameters such as the amount of training and the use of multiple reinforcers.     

Facilitation of instrumental behavior by a Pavlovian appetitive conditioned stimulus

Three experiments examined appetitive Pavlovian-instrumental interactions by presenting separately trained conditioned stimuli (CSs) during reinforced instrumental responding in rabbits. Intra-oral reinforcement was used to minimize interference from peripheral responses such as magazine approach. In experiment 1, the rabbits were first trained to perform an instrumental head-raising response for sucrose reward. A conditioned jaw movement response was then established to a 2-sec CS by pairing it with sucrose; a control stimulus was unpaired with sucrose. Instrumental responding maintained by a variable-interval 40-sec schedule was enhanced during 10-sec presentations of the paired, but not the unpaired, CS. Responding on a variable-ratio 15 schedule was unaffected except on trials on which the pre-CS baseline response rate was low; in such cases the paired CS caused a long-lasting acceleration of responding. Noncontingent presentation of the sucrose reinforcer itself briefly suppressed responding but had no long-term effect. In Experiment 2, a CS that had been conditioned at a 10-sec duration produced the same pattern of effects as in the first study, indicating that facilitation resulted from CS presentation rather than from the frustrative effects of non-reinforcement of the CS. In Experiment 3 an inhibitory CS blocked facilitation by the excitatory CS but did not itself affect instrumental responding. These results support the view that Pavlovian processes play a positive role in instrumental performance and suggest that previous findings of suppression by a short-duration CS reflect peripheral interference. The dependence of facilitation on the baseline level of responding is discussed in terms of associative and motivational theories of Pavlovian mediation.     

THE EFFECTS OF CHOICE ON SELF‐CONTROL

Three adolescents with traumatic brain injury performed a physical therapy task in the absence of programmed consequences or duration requirements. Next, the experimenter gave the participants the options of a smaller immediate reinforcer with no response requirement or a larger delayed reinforcer with a response requirement. Self‐control training exposed participants to a procedure during which they chose between a smaller immediate reinforcer and a progressively increasing delayed reinforcer whose values varied and were determined by a die roll. The participants chose whether they or the experimenter rolled the die. All participants initially demonstrated low baseline durations of the physical therapy task, chose the smaller immediate reinforcer during the choice baseline, and changed their preference to the larger delayed reinforcer during self‐control training.     

TEACHING SELECTED MICROCOMPUTER SKILLS TO RETARDED STUDENTS VIA PICTURE PROMPTS

Five retarded students were taught to use picture prompts to help them access and terminate a microcomputer program. Training was provided within a multiple baseline format. Posttesting (picture prompts without feedback), and a return to baseline were later conducted for boththe training program and an untrained (generalization) program. The results indicate thatthe program was successful in teachingthe microcomputer skills tothe students. In addition, all students were able to maintain their skills over a 7-day interval in which they did not have access tothe microcomputer.     

Arousal, changeover responses, and preference in concurrent schedules

Pigeons were trained on multiple schedules that provided concurrent reinforcement in each of two components. In Experiment 1, one component consisted of a variable-interval (VI) 40-s schedule presented with a VI 20-s schedule, and the other a VI 40-s schedule presented with a VI 80-s schedule. After extended training, probe tests measured preference between the stimuli associated with the two 40-s schedules. Probe tests replicated the results of Belke (1992) that showed preference for the 40-s schedule that had been paired with the 80-s schedule. In a second condition, the overall reinforcer rate provided by the two components was equated by adding a signaled VI schedule to the component with the lower reinforcer rate. Probe results were unchanged. In Experiment 2, pigeons were trained on alternating concurrent VI 30-s VI 60-s schedules. One schedule provided 2-s access to food and the other provided 6-s access. The larger reinforcer magnitude produced higher response rates and was preferred on probe trials. Rate of changeover responding, however, did not differ as a function of reinforcer magnitude. The present results demonstrate that preference on probe trials is not a simple reflection of the pattern of changeover behavior established during training.     

Telehealth and in‐person training outcomes for novice discrete trial training therapists

The efficacy and efficiency of telehealth and in‐person training were compared while teaching seven undergraduate students to implement components of discrete trial training. A multiple‐baseline design across skills with elements of multiple probe and delayed multiple baseline combined with an alternating‐treatments design was used to evaluate the effects of behavioral skills training (BST) on (a) implementing a multiple stimulus without replacement preference assessment, (b) setting up an instructional context, (c) delivering antecedent prompts, and (d) delivering consequences for accurate and inaccurate responding. Two skills were trained via telehealth and two skills were trained in‐person using BST procedures with a mock student. All participants provided high acceptability ratings for both training procedures. Results also showed that telehealth training was as efficacious and efficient as in‐person training for all skills across all participants. Five of six participants showed high levels of maintenance of the newly acquired skills; these five also exhibited the skills during a novel instructional task.     

Elimination of position-biased responding in individuals with autism and intellectual disabilities

Five individuals with autism or other developmental disabilities participated in paired-stimulus preference assessments during repeated baseline probes. All subjects initially showed a pronounced bias by typically selecting the stimulus placed in either the left or right position. Biased responding for 3 subjects was eliminated when training trials were conducted in which a stimulus of known lesser quality was presented as one of the choices. Reinforcer-quality training was unsuccessful for 2 subjects, as was a condition in which reinforcer magnitude was modified to favor unbiased responding. These subjects' biased responding was eliminated only when a correction procedure (repetition of error trials) was implemented.     

EVALUATION OF A TRAINING MANUAL FOR THE ACQUISITION OF BEHAVIORAL ASSESSMENT INTERVIEWING SKILLS

Two procedures were used to teach behavioral assessment interviewing skills: a training manual and one-to-one instruction that included modeling, rehearsal, and feedback. Two graduate students and two advanced undergraduates were trained with each procedure. Interviewing skills were recorded in simulated assessment interviews conducted by each student across baseline and treatment conditions. Each training procedure was evaluated in a multiple baseline across students design. The results showed that both procedures were effective for training behavioral interviewing skills, with all students reaching a level of 90%-100% correct responding. Finally, a group of experts in behavior analysis rated each interviewing skill as relevant to the conduct of an assessment interview and a group of behavioral clinicians socially validated the outcomes of the two procedures.     

Transfer tests of stimulus value in concurrent chains

We report two experiments that use transfer tests to investigate whether in concurrent chains the value of a terminal-link stimulus is affected by the alternate terminal link. In Experiment 1, two groups of pigeons were trained on multiple concurrent-chains schedules in which switching between the schedules was via pecking a changeover key. For one group, the terminal links were fixed-interval 8 s versus fixed-interval 16 s in one component and fixed-interval 16 s versus fixed-interval 32 s in the other component. For a second group, the terminal links were variable-interval 10 s versus variable-interval 20 s in one component and variable-interval 20 s versus variable-interval 40 s in the other. After sufficient baseline training had been given so that performances had stabilized, transfer tests were conducted in which the two chains with equal terminal-link schedules were presented together as a new concurrent pair. For 6 of the 7 subjects, initial-link responding changed fairly rapidly during the test in the manner predicted if the values of the terminal links were equal. In Experiment 2, pigeons were trained on multiple concurrent chains using a two-key procedure, and the terminal links were the same variable-interval schedules as in Experiment 1. After baseline training, transfer tests were conducted that assessed (a) the relative reinforcing strength of the terminal-link stimuli in a novel initial-link situation and (b) the relative ability of those stimuli to evoke responding. The data from the reinforcing strength test were consistent with those from Experiment 1, but those from the evocation strength test were not. Although this discrepancy shows that responding in transfer tests is not solely a function of stimulus value, the results from both experiments suggest, overall, that value is determined by the stimulus—reinforcer relation independently of the alternative terminal link.     

Sensitivity to reinforcer duration in a self-control procedure

In a concurrent-chains procedure, pigeons' responses on left and right keys were followed by reinforcers of different durations at different delays following the choice responses. Three pairs of reinforcer delays were arranged in each session, and reinforcer durations were varied over conditions. In Experiment 1 reinforcer delays were unequal, and in Experiment 2 reinforcer delays were equal. In Experiment 1 preference reversal was demonstrated in that an immediate short reinforcer was chosen more frequently than a longer reinforcer delayed 6 s from the choice, whereas the longer reinforcer was chosen more frequently when delays to both reinforcers were lengthened. In both experiments, choice responding was more sensitive to variations in reinforcer duration at overall longer reinforcer delays than at overall shorter reinforcer delays, independently of whether fixed-interval or variable-interval schedules were arranged in the choice phase. We concluded that preference reversal results from a change in sensitivity of choice responding to ratios of reinforcer duration as the delays to both reinforcers are lengthened.     

Reversibility of single-incentive selective associations.

Rats were trained to press a lever in the presence of a tone-light compound stimulus and not to press in its absence. In each of two experiments, schedules were designed to make the compound a conditioned punisher for one group and a conditioned reinforcer for the other. In Experiment 1, one group's responding produced food in the presence of the compound but not in its absence. The other group's responding terminated the compound stimulus, and food was presented only in its absence. When tone and light were later presented separately, light controlled more responding than did tone in the former group, but tone gained substantial control in the latter. The same effects were also observed within subjects when the training schedules were switched over groups. In Experiment 2, two groups avoided shock in the presence of the compound stimulus. In the absence of the compound, one group was not shocked, and the other received both response-independent and response-produced shock. When tone and light were presented separately, the former group's responding was mainly controlled by tone, but the latter group's responding was almost exclusively controlled by light. These effects were also observed within subjects when the training schedules were switched over groups. Thus, these single-incentive selective association effects (appetitive in Experiment 1 and aversive in Experiment 2) were completely reversible. The schedules in which the compound should have been a conditioned reinforcer consistently produced visual control, and auditory control increased when the compound should have become a conditioned punisher. Currently accepted accounts of selective associations based on affinities between shock and auditory stimuli and between food and visual stimuli (i.e., stimulus-reinforcer interactions) do not adequately address these results. The contingencies of reinforcement most recently associated with the compound and with its absence, rather than the nature of the reinforcer, determined whether auditory or visual stimulus control developed.     

The representation of the reinforcer and the force of the pigeon's keypeck in first and second-order conditioning

The aim of this study was to determine whether reinforcer-specific conditioned responding would occur in a situation in which responding was not thought to be mediated by a representation that encodes information about the specific properties of the reinforcer. The force of the pigeon's keypeck was monitored during first and second-order conditioning with either food or water as the unconditioned stimulus (US). Each pigeon was trained with four different stimuli: a first-order cue predicting that responding would be reinforced with grain (S1f), a first-order cue predicting water as the reinforcer (S1w), a second-order stimulus predicting the S1f (S2f), and a second-order cue predicting the S1w (S2w). Following conditioning, the pigeons were selectively satiated with one of the two reinforcers and presented with the first and second-order cues in an extinction test. At the end of training, the pigeon's keypecks were less forceful to the S1w than to the S1f. There was not, however, a reliable difference between the force of the pecks to the S2f and the S2w. These force differences are consistent with the conclusion that the topography of the keypecks was systematically related to the nature of the primary reinforcer during first but not during second-order conditioning. The results from the selective satiation test are difficult to interpret. There was no evidence to indicate that second-order responding was mediated by a detailed representation of the primary US, but a detailed representation of the reinforcer may have been mediating first-order responding. Taken together, these findings are consistent with the view that a representation of the reinforcer is an important determinant of the topography of conditioned responding.     

Fixed-time schedule effects as a function of baseline reinforcement rate

Using an arbitrary response, we evaluated fixed-time (FT) schedules that were either similar or dissimilar to a baseline (response-dependent) reinforcement schedule and extinction. Results suggested that both FT schedules and extinction resulted in decreased responding. However, FT schedules were more effective in reducing response rates if the FT reinforcer rate was dissimilar to baseline reinforcer rates. Possible reasons for this difference were evaluated with data analysis methods designed to identify adventitious response-reinforcer relations.     

Response-independent food delivery and behavioral resistance to change

Response-independent food was delivered during a dark-key phase between two multiple-schedule components to explore its disruptive effects on responding. Responding in components was maintained by separate variable-interval 120-s schedules, with a 2-s reinforcer in Component 1 and a 6-s reinforcer in Component 2. Across conditions the rate and duration of response-independent food presentations were manipulated. The results showed that response rates in both components decreased as a function of the duration and the rate of response-independent food presentations; moreover, the decrease in response rate relative to the baseline level was larger in Component 1 than in Component 2. These findings were consistent with expectations from behavioral momentum theory, which predicts that if equal disruption (response-independent food in this case) is applied to responding in two components, then the ratio of response-rate change in Component 1 versus Component 2 should remain constant, irrespective of the magnitude of that disruption.