Emergent equivalence relations between interoceptive (drug) and exteroceptive (visual) stimuli

Environmental cues can indirectly acquire cocaine-eliciting changes in Heart Rate: A pilot study of derived relational responding, the transfer of function among cocaine users

Identifying the processes by which environmental stimuli can come to influence drug use is important for developing more efficacious interventions. This study investigated derived relational responding and the transfer of differential conditioned effects of environmental stimuli paired with "smoked" cocaine in accordance with the relations of symmetry, transitivity, and equivalence using Heart Rate as the measure of conditioning among 12 adults with significant histories of cocaine use. Match-to-sample (MTS) procedures were used to test for emergent relations among two four-member stimulus groupings. One member of a group was then paired with 25-mg of smoked cocaine and one member of the other group was paired with 0-mg of smoked cocaine. 10 participants completed the MTS protocol: 4 participants demonstrated two four-member equivalence classes, 3 participants demonstrated two three-member equivalence classes and 2 participants demonstrated symmetry only. One participant demonstrated no derived relations. Differential respondent elicited changes in HR was demonstrated in the presence of stimuli paired with smoked cocaine among 4 of the 6 participants completing the conditioning phase; all 4 of the participants demonstrated a bi-directional transfer of these functions in accordance with symmetry. Transfer was not reliably demonstrated in accordance with transitive or equivalence relations. The results suggest that drug respondent elicitation in the context of drug use may be a function of both direct conditioning and relational processes. These findings have implications for studying and understanding the processes by which stimuli in the natural ecology can set the occasion for cocaine use and developing cocaine use disorder.

An update on the search for symmetry in nonhumans

Sidman et al.'s (1982) failure to find evidence for symmetry (bidirectional associations between stimuli) in monkeys and baboons set the stage for decades of work on emergent relations in nonhumans. They attributed the failure to the use of procedures that did not (1) promote stimulus control based on the relation between the sample and correct comparison and (2) reduce control by irrelevant stimulus features. Previous reviews of symmetry in nonhumans indicated that multiple exemplar training and successive matching might encourage appropriate stimulus control. This review examined 16 studies that investigated symmetry in 94 subjects, including pigeons, rats, capuchin monkeys, and baboons. Several studies used alternative training procedures to minimize sources of irrelevant stimulus control, and many combined multiple exemplar training with other procedural modifications. Symmetry was observed in approximately 30% of subjects. Studies that reported the strongest evidence for symmetry used successive matching-to-sample procedures that included training on both symbolic and identity relations, and studies finding mixed evidence employed alternative methods. These studies highlight the challenge in creating training procedures that promote symmetry and the need to assess the underlying sources of control on positive demonstrations.

Developing Improved Translational Models of Pain: A Role for the Behavioral Scientist

The effective management of pain is a longstanding public health concern. Although opioids have been frontline analgesics for decades, they also have well-known undesirable effects that limit their clinical utility, such as abuse liability and respiratory depression. The failure to develop better analgesics has, in some ways, contributed to the escalating opioid epidemic that has claimed tens of thousands of lives and has cost hundreds of billions of dollars in health-care expenses. A paradigm shift is needed in the pharmacotherapy of pain management that will require extensive efforts throughout biomedical science. The purpose of the present review is to highlight the critical role of the behavioral scientist to devise improved translational models of pain for drug development. Despite high heterogeneity of painful conditions that involve cortical-dependent pain processing, current models often feature an overreliance on simple reflex-based measures and an emphasis on the absence, rather than presence, of behavior as evidence of analgesic efficacy. Novel approaches should focus on the restoration of operant and other CNS-mediated behavior under painful conditions.

Male Smokers’ Behavioral and Brain Responses to Deviant Cigarette-Related Stimuli in a Two-Choice Oddball Paradigm

Abstract. Experimental studies on smoking and response-inhibition capacity have revealed inconsistent findings, which might be due to differences in sensitivity of the behavioral paradigms used. Here we aimed to replicate the impaired response inhibition in male smokers that was found in a previous study using a two-choice oddball task. This task enables the use of response times as index of inhibition capacity and equalizes the response requirement for the different trial types. In addition, we measured event-related brain potentials to explore the nature of the cognitive processes underlying the behavioral difference. Smokers (n = 19) and non-smokers (n = 19) were asked to make a different response to frequent standard stimuli (cigarette-unrelated pictures) than to infrequent deviant stimuli (cigarette-related pictures). Compared to non-smokers, smokers took a longer time to respond to deviant but not standard stimuli. In addition, smokers, but not non-smokers, displayed a smaller N2 amplitude to deviant than standard stimuli, and only the non-smokers showed larger P3 amplitudes to deviant compared to standard stimuli. Moreover, the response time (RT) measure was differentially correlated with N2 and P3 amplitudes in smokers and non-smokers. The joint results support the notion of deviant cognitive processes in smokers compared to non-smokers that are either directly or indirectly related to response-inhibition capacity.

Why We Are Still Not Acting to Save the World: the Upward Challenge of a Post-Skinnerian Behavior Science

Basic research on derived stimulus relations reveals many effects that may be useful in understanding and resolving significant and complex societal problems. Applied research on derived stimulus relations has done little to fulfill this promise, focusing instead mainly on simple demonstrations of well-known phenomena. We trace the research tradition of derived stimulus relations from laboratory to wide-scale implementation, and put forward several suggestions for how to progress effective and impactful research on derived relational responding to issues of immense social importance. To advance a science of behavior from relative social obscurity to the developing world-saving technologies, we must evaluate our own behavior as scientists in the grander social context.

Derived relations moderate the association between changes in the strength of commitment language and cocaine treatment response

The psycholinguistic analysis of client-counselor interactions indicates that how individuals talk about their substance use is associated with treatment outcome. However, the processes by which client speech influences out-of-session behaviors have not been clearly delineated. This study investigated the relationships between deriving relations-a key behavioral process by which language and cognition may come to influence behavior, shifts in the strength of client talk in favor of change, and treatment outcome among 75 cocaine-dependent participants (23% Female). Participants were trained to relate cocaine words, nonsense syllables, and negative-consequence words and were then assessed for a derived relation of equivalence before starting treatment. The DARN-C coding system was used to quantify the strength of participant speech during an early cognitive behavior therapy counseling session. Cocaine use during treatment was the outcome of interest. The analyses (a) characterized the process of deriving relations among individuals seeking help for their misuse of cocaine, (b) tested the relationships between shifts in the strength of participants' speech in favor of change and treatment outcome, and (c) tested if deriving equivalence relations moderated the relationship between shifts in the strength of in-session speech and treatment response. Results indicated that a minority of participants derived equivalence relations, however increases in the strength of commitment language predicted less cocaine use during treatment only among those who did. The findings suggest deriving relations may be an important process by which changes in the strength of commitment language comes to influence substance use.

Drug Discrimination and the Analysis of Private Events

A defining feature of radical behaviorism is the explicit inclusion of private events as material phenomena within a science of behavior. Surprisingly, however, despite much theorizing, there is a notable paucity within behavior analysis of controlled experimentation and analysis of private events, especially in nonhuman animals. One technique that is amenable to the study of private events is drug discrimination. For over 40 years, drug discrimination procedures have been an incredibly effective tool providing a wealth of in vivo pharmacological information about drugs including receptor selectivity, potency, and efficacy. In addition, this procedure has provided important preclinical indications of abuse liability. However, despite its prowess as a pharmacologic tool, or perhaps because of it, empirical investigation of its parameters, procedural elements, and variants is not currently an active research domain. This review highlights the drug discrimination procedure as a powerful means to systematically investigate private events by using drugs as interoceptive stimuli. In addition to the opportunity to study privacy, empirical evaluation of the drug discrimination procedure will likely inform and improve the standard practice for future endeavors in basic and clinical pharmacology.

Negative mood reverses devaluation of goal-directed drug-seeking favouring an incentive learning account of drug dependence

BACKGROUND

Two theories explain how negative mood primes smoking behaviour. The stimulus-response (S-R) account argues that in the negative mood state, smoking is experienced as more reinforcing, establishing a direct (automatic) association between the negative mood state and smoking behaviour. By contrast, the incentive learning account argues that in the negative mood state smoking is expected to be more reinforcing, which integrates with instrumental knowledge of the response required to produce that outcome.

OBJECTIVES

One differential prediction is that whereas the incentive learning account anticipates that negative mood induction could augment a novel tobacco-seeking response in an extinction test, the S-R account could not explain this effect because the extinction test prevents S-R learning by omitting experience of the reinforcer.

METHODS

To test this, overnight-deprived daily smokers (n = 44) acquired two instrumental responses for tobacco and chocolate points, respectively, before smoking to satiety. Half then received negative mood induction to raise the expected value of tobacco, opposing satiety, whilst the remainder received positive mood induction. Finally, a choice between tobacco and chocolate was measured in extinction to test whether negative mood could augment tobacco choice, opposing satiety, in the absence of direct experience of tobacco reinforcement.

RESULTS

Negative mood induction not only abolished the devaluation of tobacco choice, but participants with a significant increase in negative mood increased their tobacco choice in extinction, despite satiety.

CONCLUSIONS

These findings suggest that negative mood augments drug-seeking by raising the expected value of the drug through incentive learning, rather than through automatic S-R control.

A Behavior Analytic Interpretation of Alexithymia

Alexithymia is a term used to describe individuals who seem unable to experience or at least describe emotions. This paper offers a theoretical interpretation of alexithymia from a radical behaviorist perspective. While there have been attempts to explain the etiology of alexithymia, the current analysis is unique in that it provides direct treatment implications. The pragmatic analysis described focuses on the verbal behavior of individuals rather than looking "inside" for explanations. This is supported by a review of experimental research that has failed to find consistencies among alexithymic individuals' physiological responding. Descriptions of the various discriminative and consequential stimulus conditions involved in the complex learning histories of individuals that could result in an alexithymic presentation are provided. This analysis helps situate the alexithymia construct in a broader behavior analytic understanding of emotions. Finally this paper outlines implications for assessment and treatment, which involve influencing discriminative and consequential interpersonal stimulus conditions to shape verbal behavior about emotions.

Private events: Do they belong in a science of human behavior?

The role of thinking, feeling, and other private events has received a great deal of attention in mainstream psychology but has been virtually ignored in behavior analysis until recently. This paper introduces a series of papers from a symposium that explored the roles of private events in a science of human behavior. We briefly explore the role private events are assigned in several behavioral orientations. Next, we discuss several positions on how private events might be conceptualized within a behavior-analytic framework. We conclude by noting that the dearth of research and conceptualizations about private events unnecessarily limits the theoretical or conceptual understanding on which applied behavior analysts base their work. With this paper and the papers that follow, we hope to spark research, discussion, and yes, thinking, about the roles of thinking and feeling.

Why it is crucial to understand thinking and feeling: An analysis and application to drug abuse

Behavior analysis has long accepted the legitimacy of the analysis of private events in a natural science of behavior. However, the topic has languished as a focus of empirical research in either applied or basic arenas. We argue that recent empirical work examining the bidirectional nature of verbal relations may shed light on the role of private events in complex human behavior. Skinner argued that although it would be possible to analyze private events, we need not, because thoughts and feelings were viewed as co-occuring products of the same contingencies that are responsible for changes in overt responses. However, the bidirectional transformation of stimulus function inherent in verbal behavior changes the way that private events participate in complex behavioral episodes for verbal organisms. We examine why we have reached such a conclusion, with special emphasis on the role of self-awareness. Finally, we conclude with an application of our analysis to the problem of substance abuse.

Excitatory conditioning to the interoceptive nicotine stimulus blocks subsequent conditioning to an exteroceptive light stimulus

Previous research has shown that a nicotine conditional stimulus (CS) can compete with (i.e., overshadow) a brief light CS. Another form of competition, blocking, has not yet been examined with the nicotine CS. Groups of rats were assigned to an element training condition. For the N+ group, during each daily 2h element training session, there were ten intravenous nicotine infusions (0.03 mg/kg) followed 30s later with 4s access to sucrose. In the N- group, nicotine and sucrose presentations were explicitly unpaired. The chamber alone group (C alone) had no stimulus presentations. Element training was followed by compound training in all groups. A 30-s houselight was included during the time between the nicotine infusion and paired sucrose delivery. Non-reinforced element presentations assessed relative control of the goal tracking conditioned response (CR). The N+ group showed a higher proportion of CR control by the nicotine than the light. The opposite pattern was found in the N- and C alone groups indicating that nicotine CS controlled less of the CR than the light. Thus, excitatory conditioning with the nicotine CS blocked later conditioning to the light. This finding adds to literature examining the interaction between interoceptive drug CSs and other environmental stimuli.

Transfer of the discriminative stimulus effects of Δ9-THC and nicotine from one operant response to another in rats

OBJECTIVE

Transfer of the discriminative stimulus effects of two drugs from one operant (original-response) to a topographically different response (transfer-response) that was spared drug discrimination training was investigated.

MATERIALS

Eight rats were trained in a counterbalanced one manipulandum (lever press and nose poke) drug discrimination procedure. Counterbalanced IP administered nicotine (0.3 mg/kg) or Δ(9)-tetrahydrocannabinol (3.0 mg/kg) functioned as discriminative stimuli. S(D) drugs occasioned sessions of food-reinforcement (variable-interval 30-s schedule); S(Δ) drugs occasioned non-reinforcement. The original-response (lever-pressing or nose-poking) was initially reinforced during 30-min S(D) drug sessions, and non-reinforced on the other alternating S(Δ)-drug sessions.

RESULTS

Two separate 5-min non-reinforcement tests, counterbalanced by drug order, revealed stimulus control over the original-response by both drugs, which transferred to the transfer-response. Subsequent extinction training of the transfer-response attenuated the original-response response rates with the S(D) drug conditions but had little impact on discriminative control. Discriminative control was reversed for the transfer-response but had little impact on the original-response but, again, reduced response rate.

CONCLUSION

These data demonstrate that (a) discriminative control by two distinct drug states can transfer and modulate a topographically different free-operant response and, (b) as is true for exteroceptive stimuli, drug states that function as antecedents embedded within the operant three-term contingency have differing relationships with the response and the primary reinforcer.

How research in behavioral pharmacology informs behavioral science

Behavioral pharmacology is a maturing science that has made significant contributions to the study of drug effects on behavior, especially in the domain of drug-behavior interactions. Less appreciated is that research in behavioral pharmacology can have, and has had, implications for the experimental analysis of behavior, especially its conceptualizations and theory. In this article, I outline three general strategies in behavioral pharmacology research that have been employed to increase understanding of behavioral processes. Examples are provided of the general characteristics of the strategies and of implications of previous research for behavior theory. Behavior analysis will advance as its theories are challenged.

Modification of slot-machine preferences through the use of a conditional discrimination paradigm

The present experiment investigated the impact of contextually trained discriminations on gambling behavior. Nine recreational slot-machine players were initially exposed to concurrently available computerized slot machines that were each programmed on random-ratio schedules of reinforcement and differed only in color. All participants distributed responding equally across the two slot machines. A conditional discrimination procedure was then used to teach the contextual cues representing the arbitrary relations of "greater than" and "less than." Following contextual cue training, participants were reexposed to the concurrent slot-machine task. After training of the contextual cues, a higher proportion of responses were made to the slot machine that shared formal properties (i.e., color) with the contextual cue representing "greater than."

Private stimuli, covert responses, and private events: conceptual remarks

In this article, I discuss the concepts of private stimuli, covert responses, and private events, emphasizing three aspects: the conditions under which private stimuli may acquire discriminative functions to verbal responses, the conditions of unobservability of covert responses, and the complexity of events or phenomena described as private. I argue that the role of private stimuli in the control of self-descriptive verbal responses is dependent on a relation (correlation or equivalence relation) with public stimuli, and that responses vary along a continuum of observability. These remarks on private stimuli and covert responses are introductory to an examination of the varying complexity of phenomena described as private. I argue that private events is a verbal response emitted under the control of phenomena of different degrees of complexity, and I interpret these phenomena, based on the principle of selection by consequences. I introduce the notion of inclusiveness to suggest that some phenomena related to privacy are less or more complex as they include relations of a phylogenetic, ontogenetic, and cultural origin.

The effect of test schedules on the formation of linked perceptual classes

After training conditional discriminations among selected stimuli from two perceptual classes, the emergence of novel relations involving other members of both classes was assessed using cross-class probes. The cross-class probes were presented using one of four different testing schedules. In the 2/9 test, nine different probes were presented in each of two test blocks. In the 6/3 test, three different probes were presented in each of six test blocks. In the 18/1-RND test, each of the 18 cross-class probes was presented in separate test blocks. In the 2/9 and 6/3 tests, the cross-class probes were presented in a randomized order within test block. In the 18/1-RND test, the cross-class probes were presented in a randomized sequence. In the 18/1-PRGM test, however, the cross-class probes were presented in a programmed order (i.e., the values of the stimuli in each cross-class probe were changed systematically in the succession of probe presentations). About 55% of the linked perceptual classes emerged during the 2/9, 6/3, and 18/1-RND tests. Thus the number of different probes in a test block did not influence the emergence of classes as long as the probes were presented in a random order. Virtually all classes emerged during the 18/1-PRGM test. Thus at least one ordered introduction of different cross probes resulted in the reliable emergence of linked perceptual classes. Mechanisms responsible for linked perceptual class formation are discussed along with the relation of these classes to other complex categories.

The formation of linked perceptual classes

Multiple-exemplar training with stimuli in four domains induced two new fill-based (A1' and A2') and satellite-image-based (B1' and B2') perceptual classes. Conditional discriminations were established between the endpoints of the A1' and B1' classes as well as the A2' and B2' classes. The emergence of linked perceptual classes was evaluated by the performances occasioned by nine cross-class probes that contained fill variants as samples and satellite variants as comparisons, along with nine other cross-class probes that consisted of satellite variants as samples and fill variants as comparisons. The 18 probes were first presented serially and then concurrently. Class-consistent responding indicated the emergence of linked perceptual classes. Of the linked perceptual classes, 70% emerged during the initial serial test. An additional 20% of the linked perceptual classes emerged during the subsequently presented concurrent test block. Thus, linked perceptual classes emerged on an immediate or delayed basis. Linked perceptual classes, then, share structural and fuctional similarities with equivalence classes, generalized equivalence classes, cross-modal classes, and complex maturally occurring categories, and may clarify processes such as intersensory perception.

Perceptual classes established with forced-choice primary generalization tests and transfer of function

In Experiment 1, 20 college students learned two identity conditional discriminations using squares that differed in interior-fill percentage (called Fill23 and Fill77). A two-choice generalization test was then presented with number of test trials varied across groups of subjects. The test samples were 19 squares that ranged in fill value from 23% to 77%; the comparisons were squares with Fill23 and Fill77. The resulting gradients did not vary as a function of number of test trials. When the generalization test was repeated with a third comparison, "neither," the ranges of fill values that occasioned the exclusive selection of Fill23 or Fill77 were direct functions of the number of prior two-choice generalization trials. Finally, a disriminability test revealed that Fill23 and Fill77 were disciminable from the intermediate fill values. In Experiment 2, perceptual classes were established with 5 new students using 760 forced-choice generalization test trials. The student were then trained to select a different glyph in the presence of Fill23 and Fill77, followed by a three-choice generalization test in which the 19 fill stimuli served as samples and the two glyphs served as comparisons. The gradients ovelapped with those previously obtained during the three-choice generalization test that used Fill23 and Fill77 as comparisons. Finally, a discriminability test showed that many adjacent stimuli along thc fill dimension were discriminable from each other. Together, the results of both experiments suggest that ranges of fill-based stimuli functioned as members of perceptual classes, and each class also functioned as a transfer network for a new selection-based response.

Why behavior analysts should study emotion: the example of anxiety

Historically, anxiety has been a dominant subject in mainstream psychology but an incidental or even insignificant one in behavior analysis. We discuss several reasons for this discrepancy. We follow with a behavior-analytic conceptualization of anxiety that could just as easily be applied to emotion in general. Its primary points are (a) that languageable humans have an extraordinary capacity to derive relations between events and that it is a simple matter to show that neutral stimuli can acquire discriminative functions indirectly with no direct training; (b) that private events can readily acquire discriminative functions; (c) that anxiety disorders seem to occur with little apparent direct learning or that the amount of direct learning is extraordinarily out of proportion with the amount of responding; and (d) that the primary function of anxious behavior is experiential avoidance. We conclude that the most interesting aspects of anxiety disorders may occur as a function of derived rather than direct relations between public events and overt and private responses with avoidance functions. Implicit in this conclusion and explicit in the paper is the assertion that anxiety is a suitable subject for behavior-analytic study.

Predicting the extension of equivalence classes from primary generalization gradients: the merger of equivalence classes and perceptual classes

In Experiment 1, 6 college students were given generalization tests using 25 line lengths as samples with a long line, a short line, and a "neither" option as comparisons. The neither option was to be used if a sample did not go with the other comparisons. Then, four-member equivalence classes were formed. Class 1 included three nonsense words and the short line. Class 2 included three other nonsense words and the long line. After repeating the generalization test for line length, additional tests were conducted using members of the equivalence classes (i.e., nonsense words and lines) as comparisons and intermediate-length lines as samples. All Class 2 comparisons were selected in the presence of the test lines that also evoked the selection of the long line in the generalization test that had been given before equivalence class formation. Class 1 yielded complementary findings. Thus, the preclass primary generalization gradient predicted which test lines acted as members of each equivalence class. Regardless of using comparisons that were nonsense words or lines, the post-class-formation gradients overlapped, showing the substitutability of class members. Experiment 2 assessed the discriminability of the intermediate-length test lines from the Class 1 (shortest) and Class 2 (longest) lines. The test lines that functioned as members of an equivalence class were discriminable from the line that was a member of the same class by training. Thus, these test lines also acted as members of a dimensionally defined class of "long" or "short" lines. Extension of an equivalence class, then, involved its merger with a dimensionally defined class, which converted a close-ended class to an open-ended class. These data suggest a means of predicting class membership in naturally occurring categories.

Resurgence of derived stimulus relations

Resurgence has been shown in human and nonhuman operant behavior, but not in derived relational responses. The present study examined this issue. Twenty-three undergraduates were trained to make conditional discriminations in a three-choice matching-to-sample paradigm. The training resulted in three equivalence classes, each consisting of four arbitrarily configured visual stimuli. The same 12 stimuli were then reorganized, and the conditional discrimination training was repeated such that three new classes were possible. In a subsequent test of derived relations, most subjects showed response patterns that were consistent with the altered conditional discriminations. Subjects were then exposed to conditional discrimination trials under extinction. Most subjects continued to respond consistently with the most recently reinforced conditional discrimination trials. During the next phase, subjects were exposed to symmetry and equivalence trials. Responses consistent with the most recent training produced feedback saying that the responses were incorrect, whereas other responses produced no feedback. Most subjects showed a resurgence of responding that was consistent with their earlier training. Finally, subjects were exposed to conditional discrimination trials carried out in extinction. Most subjects continued to show a resurgence of responding that was consistent with their early training.