Extreme sensations – thirst, pain – can focus attention on local consequences at the expense of the overall, perhaps for good evolutionary reasons. Maybe the same phenomenon evolves from prolonged use of addictive substances. The matching law explains mistaken choice, not how a person who has confronted personal catastrophe manages to ignore it in making a locally induced choice.

The matching law accounts for both addictive behavior and the usefulness of a person's evaluating choices in overall categories. To explain why overall bookkeeping, once learned, does not easily win out over local bookkeeping, another implication of matching is needed: intertemporal bargaining. The role of melioration, though probably important for new addiction is separate.

Heyman explains useful ways to bring addictive drug use under environmental control. We doubt that relapse is explained by drug features such as immediate reinforcement, clouding of judgment, and so forth. Relapse may require explanation in terms of enduring sensitization of incentive neural substrates, but even if its causal assumptions are wrong, Heyman's model makes useful predictions for behavioral control.

Heyman's target article makes a strong case for a behavioral approach to addiction, yet some important assumptions require justification, and promising behavioral alternatives to the author's melioration approach should be considered. In particular, the behavioral economic approach to addiction appears well developed and comprehensive. How does the melioration approach complement or improve on a behavioral economic account?

The conflict between drug and conventional rewards leads to a paradox: Sanctions against drug use decrease access to conventional rewards and push drug users toward drug abuse, whereas increased access to the rewards of family, friends, and work may help reduce drug abuse. Lack of control is not specific to drug addiction and is unlikely to yield to a shift in bookkeeping.

There continues to be a debate on whether addiction is best understood as a brain disease or a moral condition. This debate, which may influence both the stigma attached to addiction and access to treatment, is often motivated by the question of whether and to what extent we can justly hold addicted individuals responsible for their actions. In fact, there is substantial evidence for a disease model, but the disease model per se does not resolve the question of voluntary control. (...) Recent research at the intersection of neuroscience and psychology suggests that addicted individuals have substantial impairments in cognitive control of behavior, but this “loss of control” is not complete or simple. Possible mechanisms and implications are briefly reviewed. (shrink)

In our target article, we proposed that addiction could be envisioned as misperformance of a decision-making machinery described by two systems (deliberative and habit systems). Several commentators have argued that Pavlovian learning also produces actions. We agree and note that Pavlovian action-selection will provide several additional vulnerabilities. Several commentators have suggested that addiction arises from sociological parameters. We note in our response how sociological effects can change decision-making variables to provide additional vulnerabilities. Commentators generally have agreed that our theory provides (...) a framework within which to site addiction and treatment, but additional work will be needed to determine whether our taxonomy will help identify and treat subpopulations within the addicted community. (shrink)

Prior to the twentieth century, theories of knowledge were inherently perceptual. Since then, developments in logic, statis- tics, and programming languages have inspired amodal theories that rest on principles fundamentally different from those underlying perception. In addition, perceptual approaches have become widely viewed as untenable because they are assumed to implement record- ing systems, not conceptual systems. A perceptual theory of knowledge is developed here in the context of current cognitive science and neuroscience. During perceptual experience, association areas in the (...) brain capture bottom-up patterns of activation in sensory-motor areas. Later, in a top-down manner, association areas partially reactivate sensory-motor areas to implement perceptual symbols. The stor- age and reactivation of perceptual symbols operates at the level of perceptual components – not at the level of holistic perceptual expe- riences. Through the use of selective attention, schematic representations of perceptual components are extracted from experience and stored in memory (e.g., individual memories of green, purr, hot). As memories of the same component become organized around a com- mon frame, they implement a simulator that produces limitless simulations of the component (e.g., simulations of purr). Not only do such simulators develop for aspects of sensory experience, they also develop for aspects of proprioception (e.g., lift, run) and introspec- tion (e.g., compare, memory, happy, hungry). Once established, these simulators implement a basic conceptual system that represents types, supports categorization, and produces categorical inferences. These simulators further support productivity, propositions, and ab- stract concepts, thereby implementing a fully functional conceptual system. Productivity results from integrating simulators combinato- rially and recursively to produce complex simulations. Propositions result from binding simulators to perceived individuals to represent type-token relations. Abstract concepts are grounded in complex simulations of combined physical and introspective events. Thus, a per- ceptual theory of knowledge can implement a fully functional conceptual system while avoiding problems associated with amodal sym- bol systems. Implications for cognition, neuroscience, evolution, development, and artificial intelligence are explored. (shrink)

Withdrawal involves emotional pain that motivates much addictive behavior. In this paper, I argue that the emotional pain of withdrawal compels much addictive behavior. Researchers have noticed this possibility but it is widely underappreciated. Among philosophers, only Hanna Pickard has discussed emotional compulsion in addiction, and the emotional aspect of withdrawal has been almost completely neglected. Accounts of emotional compulsion in the philosophical literature (from Tappolet, Elster, and Furrow) probably do not capture how the distress of withdrawal compels, so I (...) propose a more suitable account of “pathodoxastic” compulsion in addiction. On this account, the emotional pain of withdrawal compels when it undermines the ability to believe that one can continue to endure it, and therefore the ability to intend abstinence. (shrink)

A restrictive view of self-control identifies exercises of self-control with synchronic intrapsychic processes, and pictures diachronic and externally-scaffolded strategies not as proper instances of self-control, but as clever ways of avoiding the need to exercise that ability. In turn, defenders of an inclusive view of self-control typically argue that we should construe self-control as more than effortful inhibition, and that, on grounds of functional equivalence, all these diverse strategies might be properly described as instances of self-control. In this paper, I (...) take a fresh look at this debate by focusing on cases of addiction. I argue that addicted agents face a paradigmatic sort of self-control challenge, which makes addiction an important test case for theories of self-control. And I discuss evidence that highlights both the unreliability of synchronic intrapsychic strategies and the crucial role that is played by diachronic and externally-scaffolded strategies in successful attempts at achieving abstinence by addicted individuals. Abstaining addicts are a paradigmatic case of agents who successfully exercise self-control, and they mostly do so by relying on diachronic and externally-scaffolded strategies. This, I argue, lends further support to an inclusive view of self-control. (shrink)

Recent experiments have shown that when individuals with a substance use disorder are confronted with drug-related cues, they exhibit an automatically activated tendency to approach these cues. The strength of the drug approach bias has been associated with clinically relevant measures, such as increased drug craving and relapse, and activations in brain reward areas. Retraining the approach bias by means of cognitive bias modification has been demonstrated to decrease relapse rates in patients with an alcohol use disorder and to reduce (...) alcohol cue-evoked limbic activity. Here, we review empirical and theoretical literature on the drug approach bias and explore two distinct models of how the drug approach bias may be embodied. First, we consider the “biological meaning” hypothesis, which grounds the automatic approach bias in the natural meaning of the body. Second, we consider the “sensorimotor hypothesis,” which appeals to the specific sensorimotor loops involved in the instantiation of addictive behaviors as the basis of the automatic approach bias. In order to differentiate between the adequacies of these competing explanations, we present specific, predictions that each model should make. (shrink)

I discuss various theoretical issues concerning maximizing, matching, and melioration. The model of addiction based on melioration has the key feature that a reduction in drag use increases both the value of drag-taking and the value of conventional activities. I found Heyman's target article stimulating. I don't feel competent to comment on drags but I do have some thoughts, both general and specific, on the theoretical issues.

Research findings on addiction are contradictory. According to biographical records and widely used diagnostic manuals, addicts use drugs compulsively, meaning that drug use is out of control and independent of its aversive consequences. This account is supported by studies that show significant heritabilities for alcoholism and other addictions and by laboratory experiments in which repeated administration of addictive drugs caused changes in neural substrates associated with reward. Epidemiological and experimental data, however, show that the consequences of drug consumption can significantly (...) modify drug intake in addicts. The disease model can account for the compulsive features of addiction, but not occasions in which price and punishment reduced drug consumption in addicts. Conversely, learning models of addiction can account for the influence of price and punishment, but not compulsive drug taking. The occasion for this target article is that recent developments in behavioral choice theory resolve the apparent contradictions in the addiction literature. The basic argument includes the following four statements: First, repeated consumption of an addictive drug decreases its future value and the future value of competing activities. Second, the frequency of an activity is a function of its relative (not absolute) value. This implies that an activity that reduces the values of competing behaviors can increase in frequency even if its own value also declines. Third, a recent experiment (Heyman & Tanz 1995) shows that the effective reinforcement contingencies are relative to a frame of reference, and this frame of reference can change so as to favor optimal or suboptimal choice. Fourth, if the frame of reference is local, reinforcement contingencies will favor excessive drug use, but if the frame of reference is global, the reinforcement contingencies will favor controlled drug use. The transition from a global to a local frame of reference explains relapse and other compulsive features of addiction. (shrink)

This study investigated the effects of psychobiological characteristics of non-obese women with a high level of weight suppression on explicit-implicit and approach-avoidance response toward food cues, depending on hunger-satiety states. The 634 participants were divided into two groups according to their weight history. If the difference between their highest weight over the last year and their current weight was more than 5%, they were assigned to the “H-WS” group. If the difference in weight was less than 5%, they were assigned (...) to the “low level of weight suppression” group. Explicit approach and avoidance toward food were measured by self-report questionnaires. Implicit approach and avoidance toward food cues were measured using an eye-tracker. Fasting blood samples were obtained to measure fasting serum leptin levels. After this, participants consumed a standard breakfast to control the satiety level. After breakfast, explicit-implicit approach-avoidance responses were repeatedly measured at the satiety states. Self-reported body shape concerns, drive for thinness, ambivalent food craving, and bulimic behavior were also assessed. The results showed that the H-WS group had lower leptin levels, and higher body shape concerns, drive for thinness, ambivalent food craving, and bulimic behaviors compared to the L-WS group. At the explicit level, the H-WS group reported lower approach and higher avoidance to food compared to the L-WS group, regardless of hunger-satiety state. Whereas, at the implicit level, the H-WS group showed higher approach during satiety rather than during hunger states. Regardless of the hunger-satiety state, there were no significant group differences with regard to implicit avoidance between the two groups. Thus, we confirmed that a high level of avoidance toward foods was observed in the H-WS group at the explicit level but not at the implicit level. Moreover, in contrast with a high level of explicit avoidance toward palatable foods, inhibition for implicit approach toward high-calorie foods seemed to be blunted after food consumption in the H-WS group. These inconsistencies may be associated with ambivalent food craving and vulnerability to bulimic behavior among H-WS individuals. (shrink)

Research has shown that temporary task goals capture more attention than negative, threatening cues, even in anxious individuals. In the current study, we investigated whether temporary task goals...

It is difficult to accommodate compulsive drug use that destroys regulation by consequences in a unitary framework of melioration or maximization, especially as both are strategies of behavioral regulation. The “contradiction” of addictive behavior despite aversive consequences is an illusory issue because consequences that do not decrease addictive behavior cannot be considered punishing.

Heyman's model explains the irrationality of addictive behavior, but it does not satisfactorily answer the question of whether this behavior is voluntary because it does not address the issue of the choice of preference functions. Furthermore, although Heyman disconfirms the disease model of addiction, this does not resolve the issue of whether addiction should be classified as a mental illness.

Heyman's target article contributes to our understanding of addictions by offering solutions to several paradoxes and by recognizing the stable nature of addictive behavior. Previous classical and operant conditioning models have emphasized molecular processes, such as acquisition and extinction, and have failed to address the aggregate effects of long-term exposure to the contingencies of drug and alcohol use.

The understanding of decision-making systems has come together in recent years to form a unified theory of decision-making in the mammalian brain as arising from multiple, interacting systems (a planning system, a habit system, and a situation-recognition system). This unified decision-making system has multiple potential access points through which it can be driven to make maladaptive choices, particularly choices that entail seeking of certain drugs or behaviors. We identify 10 key vulnerabilities in the system: (1) moving away from homeostasis, (2) (...) changing allostatic set points, (3) euphorigenic signals, (4) overvaluation in the planning system, (5) incorrect search of situation-action-outcome relationships, (6) misclassification of situations, (7) overvaluation in the habit system, (8) a mismatch in the balance of the two decision systems, (9) over-fast discounting processes, and (10) changed learning rates. These vulnerabilities provide a taxonomy of potential problems with decision-making systems. Although each vulnerability can drive an agent to return to the addictive choice, each vulnerability also implies a characteristic symptomology. Different drugs, different behaviors, and different individuals are likely to access different vulnerabilities. This has implications for an individual's susceptibility to addiction and the transition to addiction, for the potential for relapse, and for the potential for treatment. (shrink)

The model proposed by Redish et al. considers vulnerabilities within decision systems based on expectancy-value assumptions. Further understanding of processes leading to addiction can be gained by considering other inputs to decision-making, particularly affective associations with behaviors. This consideration suggests additional decision-making vulnerabilities that might explain addictive behaviors.

Despite extinction-based processes demonstrating efficacy in the animal extinction and human anxiety literatures, extinction for substance use disorders has shown poor efficacy. Reasons for this lack of success include common threats to extinction, such as renewal and reinstatement. In recent decades, research on mindfulness for SUD has flourished, and a key aspect of these mindfulness-based interventions includes teaching individuals to stay present with whatever experience they have, even if unpleasant, without trying to change/escape/avoid it. Similarly, CET teaches individuals to not (...) escape/avoid conditioned responses by engaging in drug use behavior. This paper discusses how mindfulness-based research and practices could positively influence CET through future research, with the long-term goal of improving SUD treatment. (shrink)

The target article emphasizes the relationship between a matching law-based theory of addiction and the disease model of addiction. In contrast, this response emphasizes the relationship between the matching law theory and other behavioral approaches to addiction. The basic difference, I argue, is that the matching law specifies that choice is governed by local reinforcement rates. In contrast, economics says that overall reinforcement rate controls choice, and for other approaches there are other measures or no clear prediction at all. The (...) response also differs from the target article in that there is more emphasis on the finding that stimulus conditions determine whether choice is under local or overall reinforcement rate control. (shrink)

For use in applied settings, the melioration model will need to incorporate changes in the shapes of local value functions over time, treat current value as a continuous function of time since previous choices, and take into account discounting of the effects of current behavior on future value. The policy implications of the model for regulating drugs are limited.

Heyman's analysis of addiction in terms of matching to local relative value can be supplemented by stimulus-control processes. Stimulus equivalence can broaden the set of situations that occasion addictive behavior, and the situation-reinforcer correlation can enhance its persistence. The joint effects of stimulus-control and reinforcement processes may complicate treatment.

Study 1: The cerebral correlates of craving were investigated using fMRI during ethanol stimulation. Subjects (10 male alcoholics/10 matched nonpatients) were measured twice (patients underwent intervention). During ethanol, only patients showed subcortical-limbic (right amygdala/hippocampus) and cerebellum activation before treatment. Superior temporal sulcus activation was found after treatment. Comparison subjects showed no comparable activation shifts. The findings suggest state-dependent neurobiological correlates of cue-induced craving in alcoholics. Study 2: The self-regulation of emotional brain mechanisms was explored using real-time fMRI and biofeedback. During (...) three measurements six healthy males viewed their corresponding amygdala during sadness. Real-time data analysis was performed with sliding-window. Interindividual variability between subjects was found. (shrink)

The understanding of decision-making systems has come together in recent years to form a unified theory of decision-making in the mammalian brain as arising from multiple, interacting systems (a planning system, a habit system, and a situation-recognition system). This unified decision-making system has multiple potential access points through which it can be driven to make maladaptive choices, particularly choices that entail seeking of certain drugs or behaviors. We identify 10 key vulnerabilities in the system: (1) moving away from homeostasis, (2) (...) changing allostatic set points, (3) euphorigenic signals, (4) overvaluation in the planning system, (5) incorrect search of situation-action-outcome relationships, (6) misclassification of situations, (7) overvaluation in the habit system, (8) a mismatch in the balance of the two decision systems, (9) over-fast discounting processes, and (10) changed learning rates. These vulnerabilities provide a taxonomy of potential problems with decision-making systems. Although each vulnerability can drive an agent to return to the addictive choice, each vulnerability also implies a characteristic symptomology. Different drugs, different behaviors, and different individuals are likely to access different vulnerabilities. This has implications for an individual's susceptibility to addiction and the transition to addiction, for the potential for relapse, and for the potential for treatment. (shrink)

Heyman's target article is an analytical tour de force, but it makes too hard a distinction between voluntary and driven behavior. It is more fruitful to think about brain and behavior as shifting, interacting “agents,” represented by multiple neural circuits. This has the virtue of better connecting behavioral analysis with wet neuroscience.

Heyman makes a convincing case that a melioration choice strategy is sufficient to produce addictive behavior. But given a plethora of addiction theories, the question is whether melioration theory is superior to rivals more sophisticated than a simple disease model or operant conditioning account. Heyman offers little direct evidence that melioration actually causes the addictions we observe.

Heyman's analysis of addiction suggests that drug taking is irrational. The irrationality of drug taking, however, may depend on the acceptance of mainstream society's view of what is valuable. Consideration of the addict's viewpoint and cultural aspects of drug taking may be useful in trying to fathom the “rationality” of drug taking.

The elaborated intrusion (EI) theory of desire (Kavanagh, Andrade, & May, 2005) attributes the motivational force of cravings to cognitive elaboration, including imagery, of apparently spontaneous thoughts that intrude into awareness. We report a questionnaire study in which respondents rated a craving for food or drink. Questionnaire items derived from EI theory formed a single factor alongside factors for anticipated reward/relief, resistance, and opportunity. In a multiple regression predicting strength of craving, the first three factors accounted for 36% of the (...) variance. Opportunity did not enter the model. In a second study, the difference between individuals' strong and weak cravings to take part in a sporting activity was shown to be related to visual, auditory, and general imagery, and to anticipated reward or relief from engaging in the activity. Implications for treatment of craving-related disorders are discussed in the light of these results and of other research indicating that interference with imagery can reduce the strength of craving. (shrink)

Economic models of addiction are choice-based. These models push the choice paradigm too far by modeling addiction as rational, normative behavior. Heyman's target article provides a sensible alternative to this economic approach by emphasizing that addiction is characterized by ambivalence and a perceived loss of self control. However, matching may not be a satisfactory platform on which to build this alternative model. Matching experiments do not provide evidence of ambivalence or perceived loss of self control.

Addictive behavior has never seemed rational because it persists in spite of drastic aversive consequences. This is a particular problem for models of addiction such as operant psychology which hold that behavior is controlled by its consequences. Inspite of claims to the contrary, Heymans target article illustrates how operant psychology resolves this contradiction. By using the matching law, Heyman suggests a mechanism that explains why delayed aversive events may not control behavior, and a conceptual framework in which we can understand (...) successful therapies. (shrink)

There continues to be a debate on whether addiction is best understood as a brain disease or a moral condition. This debate, which may influence both the stigma attached to addiction and access to treatment, is often motivated by the question of whether and to what extent we can justly hold addicted individuals responsible for their actions. In fact, there is substantial evidence for a disease model, but the disease model per se does not resolve the question of voluntary control. (...) Recent research at the intersection of neuroscience and psychology suggests that addicted individuals have substantial impairments in cognitive control of behavior, but this "loss of control" is not complete or simple. Possible mechanisms and implications are briefly reviewed. (shrink)

Heyman's model, paradoxically, predicts that whereas a maximizing approach to drug choice will prevent escalation of drug use it will never yield complete abstinence. We suggest an alternative model that overcomes this difficulty by focusing on changes in drug tolerance. A small modification allows maximization to predict either abstinence or moderation (e.g., social drinking).

Over the years, many theories have been proposed to account for the aberrant behavior of drug dependent individuals. Heyman posits that the existing theories of drug dependence are inadequate to explain the complex processes inherent in human drug-taking. He proposes that incongruous behaviors that comprise addiction, such as continued drug use in spite of adverse consequences, can be explained by application of the matching law approach. While the matching law theory of addiction explains certain aspects of human behavior, its application (...) to the area of addiction must be subjected to experimental verification. (shrink)

Heyman's view that addiction can be viewed as a natural outcome predictable by melioration and the matching law is provocative. Remaining to be explained more fully, however, are exactly how his view is an improvement on other reinforcement-based accounts. Included in these elaborations should be an account of how different “bookkeeping schemes” are developed and controlled and what new approaches to treatment and prevention of drug addiction are indicated.

Elaborated Intrusion theory distinguishes between unconscious, associative processes as the precursors of desire, and controlled processes of cognitive elaboration that lead to conscious sensory images of the target of desire and associated affect. We argue that the latter play a key role in motivating human behaviour. Consciousness is functional in that it allows competing goals to be compared and evaluated. The role of effortful cognitive processes in desire helps to explain the different time courses of craving and physiological withdrawal.

Two issues are raised. (1) What is the nature of the drug effect Heyman thinks confers value to drugs? (2) What is the evidence that drug use decreases the value of drugs and of conventional incentives over the long-term? There is considerable evidence for the opposite; a persistent increase in the sensitivity of neural systems that mediate drug value.

The image of craving as a desire of unimaginable and irresistible force is poised to solve the puzzle of addiction: persistent drug use despite severe negative consequences. But the image is flawed. Drawing on science, philosophy, and first‐person testimony, I argue against irresistibility and develop a more nuanced, heterogeneous account of craving for drugs. Craving comes in three varieties, each corresponding to a kind of answer to the question why people crave drugs: cue‐induced, goal‐focused, and attachment‐based. This in turn grounds (...) an approach to addressing addiction that is humane and heterogeneous, moving beyond strategies that are fundamentally controlling. (shrink)

Melioration is not superior and may be inferior to other extensions of behavioral choice theory to addiction studies. Progress in the addiction field will be accelerated by the demise of the disease model rather than by attempting to resolve the contradictions it has created.

Knowledge of specific instances of melioration does not imply knowledge of the variables controlling behavior. Drug self-administration has been successfully analyzed in terms of standard variables such as the immediacy and magnitude of the drug reinforcer. An appeal to melioration may not be necessary.