New methodology in infant operant kicking procedures: computerized stimulus control and computerized measurement of kicking

Numerous developmental issues have been assessed using a mobile reinforcement procedure (leg kicks=operant response, movement of a 3D mobile=reinforcer). The current study addressed issues of stimulus control in the mobile procedure through implementation of computerized measurement of leg kicks and computerized control over auditory/visual reinforcers. Experiment 1 demonstrated that the computerized apparatus provides a sensitive measure of learning and memory. Experiment 2 examined the efficacy of single and multiple modality reinforcement in learning/retention of operant kicking and revealed successful acquisition with single modality reinforcement. These results suggest that the mobile procedure could be expanded to address other types of developmental questions (i.e. perception, cognition, intersensory integration) and could be modified to allow replacement of the 3D mobile with images displayed on a computer monitor, thereby extending the utility of the procedure to studies requiring precise psychophysical control over visual stimuli (i.e. object identification and categorization).     

Integrating functional neuroimaging and human operant research: brain activation correlated with presentation of discriminative stimuli

Results of numerous human imaging studies and nonhuman neurophysiological studies on "reward" highlight a role for frontal, striatal, and thalamic regions in operant learning. By integrating operant and functional neuroimaging methodologies, the present investigation examined brain activation to two types of discriminative stimuli correlated with different contingencies. Prior to neuroimaging, 10 adult human subjects completed operant discrimination training in which money was delivered following button pressing (press-money contingency) in the presence of one set of discriminative stimuli, and termination of trials followed not responding (no response-next trial contingency) in the presence of a second set of discriminative stimuli. After operant training, subjects were instructed to memorize a third set of control stimuli unassociated with contingencies. Several hours after training, functional magnetic resonance imaging was performed while subjects viewed discriminative and control stimuli that were presented individually for 1,500 ms per trial, with stimulus presentations occurring, on average, every 6 s. Activation was found in frontal and striatal brain regions to both sets of discriminative stimuli relative to control stimuli. In addition, exploratory analyses highlighted activation differences between discriminative stimuli. The results demonstrate the utility of coupling operant and imaging technologies for investigating the neural substrates of operant learning in humans.     

Operant conditioning of autobiographical memory retrieval

Functional avoidance is considered as one of the key mechanisms underlying overgeneral autobiographical memory (OGM). According to this view OGM is regarded as a learned cognitive avoidance strategy, based on principles of operant conditioning; i.e., individuals learn to avoid the emotionally painful consequences associated with the retrieval of specific negative memories. The aim of the present study was to test one of the basic assumptions of the functional avoidance account, namely that autobiographical memory retrieval can be brought under operant control. Here 41 students were instructed to retrieve personal memories in response to 60 emotional cue words. Depending on the condition, they were punished with an aversive sound for the retrieval of specific or nonspecific memories in an operant conditioning procedure. Analyzes showed that the course of memory specificity significantly differed between conditions. After the procedure participants punished for nonspecific memories retrieved significantly more specific memories compared to participants punished for specific memories. However, whereas memory specificity significantly increased in participants punished for specific memories, it did not significantly decrease in participants punished for nonspecific memories. Thus, while our findings indicate that autobiographical memory retrieval can be brought under operant control, they do not support a functional avoidance view on OGM.     

AN OPERANT TRACKING PROCEDURE IN THE AUDITORY ASSESSMENT OF PROFOUNDLY RETARDED INDIVIDUALS

The present study investigated a discrete-trials, operant tracking and a descending-series procedure for the determination of hearing levels with profoundly retarded individuals. These individuals were previously diagnosed as untestable. Following stimulus-control training with errorless discrimination procedures, hearing levels for each individual were examined with both procedures. For P-1 and P-2, the operant tracking procedure was administered following a descending-series procedure. Both were observed to “track” their own hearing levels. For P-3, the operant tracking procedure was administered first, followed by the descending-series procedure. Although P-3 also “tracked” her own hearing level, more variable responding was observed. Nonetheless, the operant tracking procedure proved quite workable and may provide for improved hearing testing with “difficult-to-test” individuals.     

Predator videos and electric shock function as punishers for zebrafish (Danio rerio)

Zebrafish (Danio rerio) are a promising animal model for studying the effects of gene–environment interactions on behavior. Two experiments were conducted to assess punishment effects of presenting predator videos (Indian leaf fish; Nandus nandus) and electric shock on operant approach responses in zebrafish. In Experiment 1, the predator video and shock stimuli were presented upon a response maintained by a single variable‐interval schedule of food reinforcement in different groups of fish. In Experiment 2, the predator video and shock stimuli were presented upon one of two response alternatives maintain by concurrently available variable‐interval schedules of food reinforcement in different groups of fish. Responding decreased when the predator video and shock stimuli were presented relative to their absence in both experiments. Moreover, responding on an unpunished alternative did not reliably decrease in Experiment 2. These results indicate that the decrease in responding resulted from the punishment contingency rather than from elicited species‐specific defense responses or conditioned avoidance. Thus, the predator video and electric shock functioned as punishers of operant behavior for zebrafish. Identifying punishers for this species could lead to research on how gene–environment interactions influence individual differences in sensitivity to punishment.     

Functions of the environment in behavioral evolution

This paper explores some of the ways in which the environment functions with respect to behavior within an explanatory framework analogous to that of evolutionary biology. In both the behavioral and organic domains, the environment functions differently with respect to individual occurrences and evolutionary units. Within the behavioral domain, the problem of accounting for an occurrence of an operant instance differs from that of accounting for the existence of the operant unit of which the instance is a part. Maintaining these distinctions in levels of analysis within the behavioral domain, we focus first on operant units and operant instances as products of evolutionary processes occurring in the behavioral domain and second upon the causal role of the environment with respect to the existence of operant units and the occurrence of operant instances. The environment's function is selective with respect to origin, maintenance, suppression, and extinction of behavioral populations. At the level of operant instances, the environment has instantiating functions-evocative or alterative. Evocative functions are exemplified by discriminative relations, and alterative functions include both conditional and motivative relations. Implications are considered regarding extension of the analogy to more complex behavior-environment relations.     

OPERANT PROCEDURES AND THE COMATOSE PATIENT

Operant procedures were tested on three patients who had been in vegetative coma for 6 months, 10 months, and 38 months. A discrete trial procedure was used to test compliance to verbal requests for three behaviors for each patient, including lateral head movement or finger movement, eye focus or eye squeeze, and mouth movement. The design for each patient consisted of multiple baselines across three behaviors with a withdrawal phase and a reinstatement phase (ABAB) for one behavior. Baseline phases were followed by contingent music phases in which 15-second taped excerpts of patients' preferred music sounded immediately following the emission of targeted behaviors. The contingent music treatment affected all three behaviors for Patient 1, but was less effective for two out of three behaviors for the second and third patients who had been in coma for more extensive periods of time. Results are discussed in terms of the potential contributions of the use of operant assessment and treatment procedures in an area of medicine where they have not been used before.     

DIFFERENTIAL RESPONSE PATTERNS TO THE CONTROL CONDITION BETWEEN TWO PROCEDURES TO ASSESS SOCIAL REINFORCERS FOR CHILDREN WITH AUTISM

Historically, reinforcer assessment procedures focus primarily on identifying nonsocial reinforcers (e.g., tangibles and edibles). Far less empirical attention has been allocated to the systematic identification of social consequences that function as reinforcers. This discrepancy is problematic given that social consequences are commonly incorporated into behavioral treatment programs without systematic evaluation of their efficacy. In this study, two methodologies (a single operant and a concurrent choice) were used to assess social reinforcers for children with autism. Results highlighted differences in response allocation to the control condition between procedures. Specifically, responding occurred in the control condition of the single‐operant procedure but not in the concurrent‐operant procedure. These differences highlight the need for further evaluation of procedures to assess social reinforcers. Copyright © 2013 John Wiley & Sons, Ltd.     

ACQUISITION,DISCRIMINATIVE STIMULUS CONTROL,AND RETENTION OF INCREASES/DECREASES IN BLOOD PRESSURE OF NORMOTENSIVE HUMAN SUBJECTS1

The aims of this study of 24 normotensive subjects were: to compare a free-operant with a discrete-trials training format; to determine the most effective training procedure by comparing instrumental conditioning with instructional set and a control; to see if both increases and decreases in blood pressure could be brought under discriminative control, and to examine the maintenance of acquired self-control of blood pressure. A 2 × 3 design was employed in which two trial formats (free operant and discrete trials) were factorially compared with three training conditions (instrumental conditioning, instructional set, and control). Instrumental conditioning was found superior to both the instructional set and control conditions in producing increases and decreases in mean diastolic blood pressure. The free-operant format led to a greater degree of learned BP control in that subjects were able to increase and decrease their blood pressure by 10% to 15% of basal value and to maintain the blood-pressure operant after contingent auditory feedback/reinforcement was removed. Training was discontinued when subjects in the other five groups failed to reach criterion after 10 consecutive acquisition sessions.     

Context extinction and associative learning in Lymnaea

Aerial respiratory behavior in the pond snail Lymnaea was operantly conditioned so that snails learned not to perform aerial respiration in a hypoxic environment. Snails were trained in either the standard context (no food odorant) or a carrot (food-odorant) context. An operant training procedure of two 45-min training sessions with a 1-h interval between the sessions followed by a third 45-min training session 18 h later was sufficient to produce associative learning and long-term memory (LTM) that persisted for at least 5 days. If, however, following the third operant training session snails received three 45-min extinction training sessions, with each extinction session separated by at least a 1-h interval, LTM was not observed when tested the following day. That is, the memory was extinguished. Extinction, however, did not occur if the context of the extinction training was different from the context of the associative training. That is, in the snails trained in the standard context, extinction did not occur if the extinction training sessions were performed in the food-odorant context and vice versa.     

Insulin, exercise, and dietary effects upon behavioral thermoregulation in albino rats

The objectives of this exploratory research were to assess the effects of insulin preparations (Humulin-regular and NPH) on operant behavior reinforced by schedules of microwave radiation in a cold environment and to measure changes in this thermoregulatory behavior as a function of exercise and food deprivation. Eight albino rats were conditioned to regulate their thermal environment with 6-sec. exposures of microwave (MW) radiation (SAR = 0.34 Watts/kg/(mW/cm2) under FR-1 and FR-10 schedules. Regular-insulin and NPH-insulin sessions were administered alternately with saline-control sessions for 8-hr. durations. Exercise in an activity wheel and 48 hr. of food deprivation (diet) were additional independent variables used to alter thermoregulation. Three randomized-block analysis of variance designs with repeated measures showed that insulin preparations resulted in a suppression of operant responding for heat, yet food deprivation increased rates of microwave responding. These data are interpreted in terms of functional relationships between ambient temperature changes, core body temperature, blood glucose fluctuations, and operant behavior.     

The role of elicited responding in behavioral contrast

An attempt was made to separate operant and elicited pecks occurring in multiple schedules of food reinforcement by moving the component stimuli to a second key, upon which pecks had no effect. The operant key stimulus was constant, regardless of the reinforcement schedule in effect. Experiments included two- and three-component multiple schedules and a comparison of the single-key and the two-key procedures. In general, conditions that typically produce positive contrast in single-key procedures reduced responding to the constant-stimulus key (induction) and increased responding to the component-stimulus key (contrast) in the two-key procedure. The results were interpreted as supporting the contention that two response classes, operant and elicited, are present in standard multiple schedules. In addition, elicited responses were strongly implicated in contrast phenomena.     

The effects of verbal operant training and response interruption and redirection on appropriate and inappropriate vocalizations

Past research has shown that response interruption and redirection (RIRD) can effectively decrease automatically reinforced motor behavior (Hagopian & Adelinis, 2001). Ahearn, Clark, MacDonald, and Chung (2007) found that a procedural adaptation of RIRD reduced vocal stereotypy and increased appropriate vocalizations for some children, although appropriate vocalizations were not targeted directly. The purpose of the current study was to examine the effects of directly targeting appropriate language (i.e., verbal operant training) on vocal stereotypy and appropriate speech in 3 children with an autism spectrum disorder. The effects of verbal operant (i.e., tact) training were evaluated in a nonconcurrent multiple baseline design across participants. In addition, RIRD was implemented with 2 of the 3 participants to further decrease levels of vocal stereotypy. Verbal operant training alone produced slightly lower levels of stereotypy and increased appropriate vocalizations for all 3 participants; however, RIRD was required to produce acceptably low levels of stereotypy for 2 of the 3 participants.     

Extinction of a discriminative operant following discrimination learning with and without errors

Different groups of pigeons were trained to respond to red and not to green with and without errors (responses to green) under a free operant procedure, in which responding to red was intermittently reinforced, and under a trial procedure in which all responses to red were reinforced. The response to red was then extinguished under a procedure in which the discriminative stimuli were successively alternated as during discrimination training. The performances of those birds that learned the discrimination without errors under the trial procedure were seriously disrupted during extinction; the birds persistently responded to green for the first time. The performances of those subjects that learned the discrimination without errors under the free operant procedure were not disrupted during extinction. In a second experiment, the same discrimination was trained without errors under a trial procedure in which the response to red was intermittently reinforced. Extinction did not disrupt discrimination performance. Thus, errorless discrimination performance was shown to remain intact during extinction so long as the response to red was intermittently reinforced during discrimination training.     

Evaluation of infant vocal conditioning.

The use of the operant conditioning paradigm, as it has been applied to infant social, vocal behavior, reflects a failure to take into account the social nature of human infants over and above the rigid theoretical rationale of the paradigm. It is argued that: (1) the baseline procedure used in operant conditioning studies is methodologically and conceptually invalid; (2) the reinforcing stimulus used in social conditioning studies elicits the very response that it is assigned to reinforce; and (3) the effect of the response-reinforcer relationship is not the reinforcement (strengthening) of vocal response rate.     

Positive and negative conditioned suppression in the pigeon: Effects of the locus and modality of the CS

In Experiment I, four pigeons were exposed to trials in which a 12-sec key light illumination was followed by free food. These trials were superimposed upon a baseline of key pecking for food reinforcement on a variable-interval schedule. When the signal for food was on the operant key, response rate was substantially higher during the signal than during the baseline procedure. When the signal was on a second, signal key, operant responding was suppressed during the signal and substantial pecking of the signal key occurred. The sum of signal key and operant key pecks far exceeded the operant baseline rate of responding. An explanation of opposite results obtained with rats and pigeons as subjects in experiments of this type was suggested in terms of the spatial relation between the signal for free food and the operant target which usually characterizes these experiments. Experiment II assessed the importance of signal location when shock rather than food was the US. Suppression of operant key pecking was unaffected by signal location. Experiment III assessed the relative effectiveness of visual and auditory stimuli (clicks) as signals for food and shock, and found that all combinations of signal and US were equally effective in suppressing operant key responding. The three experiments together suggested that the identification of important effects of species—typical behavior in one experimental situation does not imply that there will be like effects in similar situations.     

Insulin and dextrose effects on fixed-interval behavioral thermoregulation in albino rats

This study is a systematic replication of the effects of insulin doses on operant behavior reinforced (in an earlier study) by fixed-ratio schedules of microwave (MW) reinforcement. In this study, insulin and dextrose doses were administered (ip) prior to fixed-interval 2-min. schedules of MW reinforcement in rats tested in a cold environment. Six Sprague-Dawley rats were conditioned to regulate their thermal environment with 5-sec. exposures of MW radiation (SAR = 0.34 Watts/kg/(mW/cm2) under the FI-2' schedules. Humulin-regular insulin and 50% solutions of dextrose were administered (ip) alternately with saline control sessions for 8-hr. durations. A within-subjects, repeated-measures 4 x 8 x 3 factorial analysis of variance design showed that insulin doses suppressed operant responding for heat, which confirmed the results of the earlier study under a different schedule. In addition, high doses of dextrose had similar suppressing effects on operant responding for heat. The data are interpreted in terms of the discriminative properties of increased thermogenesis produced by the insulin and dextrose doses. The suppressing effects were more pronounced for the first two hours, yet they persisted for approximately six hours of the 8-hr. sessions.     

Perhaps more Consideration of Pavlovian-Operant interaction May Improve the Clinical Efficacy of Behaviorally Based Drug Treatment Programs

Drug abuse remains costly. Drug-related cues can evoke cue-reactivity and craving, contributing to relapse. The Pavlovian extinction-based cue-exposure therapy (CET) has not been very successful in treating drug abuse. A functional operant analysis of complex rituals involved in CET is outlined and reinterpreted as an operant heterogeneous chain maintained by observing responses, conditioned reinforcers, and discriminative stimuli. It is further noted that operant functions are not predicated on Pavlovian processes but can be influenced by them in contributing to relapse; several empirical studies from the animal and human literature highlight this view. Cue-reactivity evoked by Pavlovian processes is conceptualized as an operant establishing/motivating operation. CET may be more effective in incorporating an operant-based approach that takes into account the complexity of Pavlovian-operant interaction. Extinction of the operant chain coupled with the shaping of alternative behaviors is proposed as an integrated therapy. It is proposed that operant-based drug abuse treatments (contingency management, voucher programs, and the therapeutic work environment) might consider incorporating cue-reactivity, as establishing/motivating operations, to increase long-term success—a hybrid approach based on Pavlovian-operant interaction

     

Voluntary Blood Pressure Control: Operant Conditioning by a Continuous Blood Pressure Feedback Technique

Abstract

The present study evaluated a single session operant conditioning of blood pressure in borderline hypertensives. A double blind randomized two period (each lasting for 20 minutes) cross over study consisting of a treatment (operant conditioning of mean arterial blood pressure) and a control condition (heart rate) was performed. Sequence of treatments was randomly assigned. Fourteen borderline hypertensive subjects participated and were trained to decrease their continuously measured blood pressure (Finapres) and heart rate. Subjects receiving blood pressure feedback during the first session showed a significant (4.3 mmHg) decrease in diastolic blood pressure. In contrast, subjects receiving blood pressure training during the second session showed a non-significant increase in diastolic blood pressure. Treatment consisting of more sessions is a promising adjunct to antihypertensive regimens.     

An intrusive and restrictive alternative to contingent shock

A 31-year-old man, a New Zealander with severe developmental disability, engaged in life-threatening operant vomiting. His therapists and two consultant behavior analysts recommended applying for a Court order to evaluate treatment that included the short-term use of contingent shock. In Court, others gave expert testimony that positive procedures alone would be sufficient and effective. Following the Court's decision against contingent shock, professionals who were responsible for ensuring compliance with the decision did not identify a nonaversive intervention. Consequently, the client was subjected to an intrusive medical procedure (chronic nasogastric intubation) and a severely restricted environment. This intervention was continued for 1 year. Problems that resulted from conflicting expert testimony on treatment alternatives are discussed.