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High-frequency gamblers show increased resistance to extinction following partial reinforcement
... We report an experiment investigating the effects of partial reinforcement and timing on perseverative gambling behavior, as these may underpin part of the transition to problem gambling. Deficits in processing partial reinforcement have been previously observed in heavy gamblers (Horsley et al., 2012), while increasing inter trial intervals (ITIs) facilitates the acquisition of conditioned behavior (Gallistel and Gibbon, 2000). In this report we outline an experiment in which participants played on a simulated slot machine on which win frequency and ITI were manipulated between groups and perseverance in extinction was measured. ...
... The partial reinforcement extinction effect (PREE) is a behavioral paradox in which weakly reinforced behaviours persist for longer without reinforcement relative to more consistently occurring reinforcers (Mackintosh, 1974;Bouton et al., 2014), such as during an extended period of losses in gambling (Dickerson, 1979;Fantino et al., 2005;Horsley et al., 2012). Partial reinforcement deficits have been identified in high frequency gamblers 1 , who take longer than recreational gamblers to extinguish these associations (Horsley et al., 2012), a change that might occur from chronic exposure to the schedules of reinforcement in gambling. ...
... The partial reinforcement extinction effect (PREE) is a behavioral paradox in which weakly reinforced behaviours persist for longer without reinforcement relative to more consistently occurring reinforcers (Mackintosh, 1974;Bouton et al., 2014), such as during an extended period of losses in gambling (Dickerson, 1979;Fantino et al., 2005;Horsley et al., 2012). Partial reinforcement deficits have been identified in high frequency gamblers 1 , who take longer than recreational gamblers to extinguish these associations (Horsley et al., 2012), a change that might occur from chronic exposure to the schedules of reinforcement in gambling. Horsley et al. (2012) report that although partial reinforcement is hypothesized to be an important component in gambling, the evidence base is sparse. ...
Manipulating different behavioral characteristics of gambling games can potentially affect the extent to which individuals persevere at gambling, and their transition to problematic behaviors. This has potential impact for mobile gambling technologies and responsible gambling interventions. Two laboratory models pertinent to this are the partial reinforcement extinction effect (PREE) and the trial spacing effect. Both of these might speed up or delay the acquisition and extinction of conditioned behavior. We report an experiment that manipulated the rate of reinforcement and inter trial interval (ITI) on a simulated slot machine where participants were given the choice between gambling and skipping on each trial, before perseverative gambling was measured in extinction, followed by measurements of the illusion of control, depression and impulsivity. We hypothesized that longer ITI’s in conjunction with the low rates of reinforcement observed in gambling would lead to greater perseverance. We further hypothesized, given that timing is known to be important in displaying illusory control and potentially in persevering in gambling, that prior exposure to longer intervals might affect illusions of control. An interaction between ITI and rate of reinforcement was observed, as low reinforced gamblers with a long ITI gambled for longer. Respondents also displayed extinction and a PREE. Gamblers exposed to a higher rate of reinforcement gambled for longer in acquisition. Impulsivity was associated with extended perseverance in extinction, and more depressed gamblers in the high reinforcement short ITI group persevered for longer. Performance in the contingency judgment failed to support the second hypothesis: the only significant contrast observed was that participants became better calibrated as the task progressed.
... In the stochastic and continuously changing environment, the extinction of probabilistic rewards is important for survival and failure in the extinction of probabilistic rewards leads to maladaptation such as pathological gambling [6,7]. In cases of the extinction of probabilistic rewards, the amount of arousal elicited by the cessation of those rewards increases with the reward probability. ...
... However, the low arousal of the gamble which changes slowly would prevent negative prediction errors in frequent losses from driving extinction [7]. Pathological gambling patients might tend to develop lower arousal of gambles or may tend to be reluctant to modify these values, once established [6]. ...
Because most rewarding events are probabilistic and changing, the extinction of probabilistic rewards is important for survival. It has been proposed that the extinction of probabilistic rewards depends on arousal and the amount of learning of reward values. Midbrain dopamine neurons were suggested to play a role in both arousal and learning reward values. Despite extensive research on modeling dopaminergic activity in reward learning (e.g. temporal difference models), few studies have been done on modeling its role in arousal. Although temporal difference models capture key characteristics of dopaminergic activity during the extinction of deterministic rewards, they have been less successful at simulating the extinction of probabilistic rewards. By adding an arousal signal to a temporal difference model, we were able to simulate the extinction of probabilistic rewards and its dependence on the amount of learning. Our simulations propose that arousal allows the probability of reward to have lasting effects on the updating of reward value, which slows the extinction of low probability rewards. Using this model, we predicted that, by signaling the prediction error, dopamine determines the learned reward value that has to be extinguished during extinction and participates in regulating the size of the arousal signal that controls the learning rate. These predictions were supported by pharmacological experiments in rats.
... Theoretically, this distinction is important because it is known that player behavior on activities such as slots can be influenced by the schedule of reinforcement (Delfabbro & Winefield, 1999;Dickerson et al., 1992). Higher volatility (and less frequent larger rewards) could potentially strengthen the partial reinforcement extinction effect (PREE) (Ferster & Skinner, 1957;Horsley et al., 2012;Skinner, 1953) and make players more resistant to extinction or periods without reward (Capaldi, 1957). The prospect of larger wins may also have the effect of encouraging chasing behavior (O'Connor & Dickerson, 2003) and may be more highly reinforcing particularly for higher risk gamblers (Knutson et al., 2001;Turner et al., 2006). ...
... play in studies of gambling behavior over longer periods of time (e.g. Horsley et al., 2012). This points toward one possible explanation of the differences between the datasets. ...
Volatility refers to the variability of bet outcomes in gambling and has been recognized as a potentially important influence on behavior. The research literature has developed competing ideas for how different behavioral responses to volatility might influence player risk. However, few empirical studies have investigated how volatility influences player behavior in a live-play, real-money environment. This paper studies 4,281 regular online slot players from two operators in the UK-one casino-focused, one bingo-focused. Longitudinal panel regressions analyze variation in players' daily session time, financial loss and declined deposits as they switched among slots games with different volatilities relative to their usual play. The findings indicate that the relationship between game volatility and player behavior is complex and often non-linear. For slots players in the casino-focused sample, lower levels of volatility than usual were typically associated with lower than average losses, declined deposits and session time. However, significant relationships were not detected in the bingo-focused operator sample. Collectively, these findings suggest that while volatility may be an important influence on behavior, this influence is not necessarily uniform or easily generalized from one population of players to another.
... Indeed, research has clearly demonstrated that partial reinforcement (i.e. occasional rewards) is more resistant to extinction 8 than continuous reinforcement Horsley et al, 2012). proposed that sports betting operated on a variable ratio and fixed interval schedule of reinforcement. ...
... With specific reference to gambling situations, research demonstrates that sustained and persistent gambling was most prevalent in conditions of maximum uncertainty regarding the distribution of rewards (Fiorillo et al, 2003;Horsley et al, 2012). It is argued that when wins are more unpredictable it may be harder for a player to stop playing because of a powerful combination of a) larger wins and b) the acknowledgement that the next bet or spin could be the winning one (Haw, 2008a;Johansson et al, 2009;Turner & Horbay, 2004). ...
The aim of this report is to review evidence and theory regarding the gambling
product through its structural characteristics (i.e., the ‘agent’ component of the
epidemiological triangle). By providing a better understanding of structural
characteristics, stakeholders should be better equipped to promote and evaluate
responsible gambling and harm-minimisation strategies. Structural characteristics are essentially the building blocks of a gambling game. They are the basis for their differential appeal depending on how they satisfy
different needs for different consumers. They combine with environmental and individual factors to determine both positive and negative outcomes of gambling participation. Structural characteristics vary considerably from game to game and evolve quickly in response to changes in technology; this renders associated policymaking challenging. The report is structured to consider categories of structural characteristics. Within
each section we consider the theory and evidence concerning the possible links between characteristics and gambling problems, together with potential implications for specific interventions that may merit consideration by regulators and commercial gambling providers.
... Gambling behavior is a complex phenomenon that can lead to serious deleterious consequences for an individual in the familial, social and financial spheres (for a review, see Raylu and Oei 2002). A large body of research has identified a plethora of factors related to gambling, including social (Gupta and Derevensky 1997) and neurobiological (Potenza 2008;Goudriaan et al. 2004) factors, and pavlovian and operant conditioning (Horsley et al. 2012;Dickerson 1979;James, O'Malley, and Tunney 2016). A consistent feature of gambling behavior is the tendency to overvalue the occurrence of a win and to undervalue the (more frequent) occurrence of a loss. ...
Among the different procedures that model gambling behavior in non-human animals, the "suboptimal choice procedure" has been extensively employed for analyzing the impact of environmental cues on choice behavior. It has been repeatedly demonstrated that pigeons prefer an alternative that infrequently presents a stimulus that signals a larger amount of reinforcement, than another alternative that always presents a stimulus associated with a smaller amount of reinforcement, even though the net rate of reinforcement is lower in the former. In the present study, we tested rats in the magnitude version of the suboptimal choice procedure. Eight rats were given a choice between two alternatives: a) one in which a stimulus predicting the delivery of ten pellets was presented with probability (p) = 0.2 and a stimulus predicting zero pellets was presented with p = 0.8, and b) one in which either of two stimuli predicted the delivery of three pellets with p= 1.0. Contrary to the consistent and robust suboptimal behavior of pigeons, rats preferred the optimal alternative. This effect occurred despite the high index of discrimination of the stimuli associated with the different outcomes shown by the rats. The relevance of this result to the development of animal models of gambling behavior is discussed.
... The random ratio is similar to the variable ratio schedule of reinforcement. This schedule of reinforcement has long been demonstrated to rapidly produce a frequent level of gambling that is difficult to suppress (Dickerson, 1984;Skinner, 1972) and has been found to take longer to extinguish in high-frequency gamblers (Horsley, Osborne, Norman, & Wells, 2012), showing deficits in partial reinforcement that demonstrate themselves in greater perseverative gambling not unlike loss-chasing. There is some evidence that longer delays between gambles contributes to continued play, in the form of lottery games (Griffiths & Auer, 2013)gambling prevalence research has consistently found that lottery games are amongst the most popular with the general public (Sproston, Erens, & Orford, 2000;Wardle, Moody, Spence, et al., 2011) and often have large latencies between gambles. ...
This manuscript reviews the extant literature on key issues related to mobile gambling and considers whether the potential risks of harm emerging from this platform are driven by pre-existing comorbidities or by psychological processes unique to mobile gambling. We propose an account based on associative learning that suggests this form of gambling is likely to show distinctive features compared with other gambling technologies. Smartphones are a rapidly growing platform on which individuals can gamble using specifically designed applications, adapted websites or text messaging. This review considers how mobile phone use interacts with psychological processes relevant to gambling, the games users are likely to play on smartphones, and the interactions afforded by smartphones. Our interpretation of the evidence is that the schedules of reinforcement found in gambling interact with the ways in which people tend to use smartphones that may expedite the acquisition of maladaptive learned behaviours such as problem gambling. This account is consistent with existing theories and frameworks of problem gambling and has relevance to other forms of mobile phone use.
... Many of these studies have looked at different aspects of gambling, such as machine preference (Dymond, McCann, Griffiths, Cox, & Crocker, 2012), rate of gambling (Dixon et al., 2010), post reinforcement pauses (Delfabbro & Winefield, 1999), latencies between gambles (James, O'Malley, & Tunney, in press), fixed interval schedules in betting (Dickerson, 1979), the random ratio schedule of reinforcement (Crossman, Bonem, & Phelps, 1987; Haw, 2008; Hurlburt, Knapp, & Knowles, 1980) and perseverance during extinction (). Similar to drug addictions, these have also looked at the role of different types of reinforcement in addictive gambling and changes in behavioural processes (Horsley, Osborne, & Wells, 2012). The concept that different types of reinforcement drive distinct subtypes of gambler is central to models of problem gambling (Blaszczynski & Nower, 2002; Sharpe, 2002). ...
This manuscript overviews the behavioural (i.e. associative learning, conditioning) research in behavioural addictions, with reference to contemporary models of substance addiction and ongoing controversies in the behavioural addictions literature. The role of behaviour has been well explored in substance addictions and gambling but this focus is often absent in other candidate behavioural addictions. In contrast, the standard approach to behavioural addictions has been to look at individual differences, psychopathologies and biases, often translating from pathological gambling indicators. An associative model presently captures the core elements of behavioural addiction included in the DSM (gambling) and identified for further consideration (internet gaming). Importantly, gambling has a schedule of reinforcement that shows similarities and differences from other addictions. While this is more likely than not applicable to internet gaming, it is less clear whether it is so for a number of candidate behavioural addictions. Adopting an associative perspective, this paper translates from gambling to video gaming, in light of the existing debates on this matter and the nature of the distinction between these behaviours. Finally, a framework for applying an associative model to behavioural addictions is outlined, and it's application toward treatment.
... Addictive behaviours are also difficult to extinguish [7,8]. We would expect to see other features common in gambling and substance addictions, such as a persistence in the behaviour after the reinforcing properties of the behaviour have been removed [9]. For example, the pattern of rewards in some games can lead some gamblers to continue to gamble long after they have stopped winning [10]. ...
The criteria used to determine a behavioral addiction should be based on an understanding of the underlying psychological mechanisms. This should include an analysis of whether the behavior itself has psychological features that might externally determine the individual’s behavior.
... In many risky-choice paradigms, reward omission is the primary loss type, and in accordance with win-stay-lose-shift behavior, reward omission should, but may not, effectively inhibit the continuation of the corresponding behavior (see Horsley, Osborne, Norman, & Wells, 2012; also see Domjan, 2010). One possible explanation for this ineffectiveness relates to the nature of the corresponding feedback of the behavior that resulted in reward omission. ...
Risky decisions are inherently characterized by the potential to receive gains or incur losses, and these outcomes have distinct effects on subsequent decision-making. One important factor is that individuals engage in loss-chasing, in which the reception of a loss is followed by relatively increased risk-taking. Unfortunately, the mechanisms of loss-chasing are poorly understood, despite the potential importance for understanding pathological choice behavior. The goal of the present experiment was to illuminate the mechanisms governing individual differences in loss-chasing and risky-choice behaviors. Rats chose between a low-uncertainty outcome that always delivered a variable amount of reward and a high-uncertainty outcome that probabilistically delivered reward. Loss-processing and loss-chasing were assessed in the context of losses disguised as wins (LDWs), which are loss outcomes that are presented along with gain-related stimuli. LDWs have been suggested to interfere with adaptive decision-making in humans and thus potentially increase loss-making. Here, the rats presented with LDWs were riskier, in that they made more choices for the high-uncertainty outcome. A series of nonlinear models were fit to individual rats’ data to elucidate the possible psychological mechanisms that best account for individual differences in high-uncertainty choices and loss-chasing behaviors. The models suggested that the rats presented with LDWs were more prone to showing a stay bias following high-uncertainty outcomes compared to rats not presented with LDWs. These results collectively suggest that LDWs acquire conditioned reinforcement properties that encourage continued risk-taking and increase loss-chasing following previous high-risk decisions.
... The certain rats from both strains (not sensitized) extinguished rapidly and at similar rates. In the same vein, in a computerized human gambling task, high-frequency gamblers were shown to respond more in extinction than low-frequency gamblers when trained under partial reinforcement, but not when trained under continuous reinforcement (Horsley, Osborne, Norman, & Wells, 2012). Like drugs of abuse, gambling has the effect of increasing persistence of seeking and consumption behaviors despite negative effects or events (for a recent literature review, see Singer, Anselme, Robinson, & Vezina, 2020). ...
Uncertainty is a common feature of the real world for many organisms, including humans. However, uncertainty is also the source of a constant dilemma that has to be solved by organisms to maintain their safety: avoiding it when possible while being ready to deploy some effort to counter its unavoidable consequences. When an uncertain outcome is crucial for survival (e.g., food), it may seem obvious to say that the individual ought to be invested in reward procurement rather than giving up. Many experimental studies confirm that a conditioned stimulus (CS) unreliably predictive of food delivery generates higher response rates in various animal species than the same CS reliably predictive of food on each trial. Here, the crux issue is to try to understand the psychological mechanism responsible for the investment in a reward-related task whose pay-off is not guaranteed. Is it aversion-induced frustration? Or is it motivational attraction resulting from incentive salience? I show that neither of these two theories is fully convincing. I argue that uncertain individuals “hope” for reliable CS-Reward associations instead of being focused on aversive uncertainty or attractive reward per se.
... The effects of reinforcement, punishment, extinction, discrimination training, and relational training on behavior are pertinent to organisms of all populations. Even where there are differences between populations, the differences are still attributable to behavioral processes to which any organism of any population is susceptible (e.g., gamblers exhibit a resistance to extinction, and if the conditions were right, people other than gamblers could exhibit that resistance too; see, e.g., Horsley, Osborne, Norman, & Wells, 2012). The generality of behavioral processes means that any experimental result emanating from the general process approach is about the larger population of interest (i.e., the population identified and defined based on your investigative goals). ...
Randomization tests are a class of nonparametric statistics that determine the significance of treatment effects. Unlike parametric statistics, randomization tests do not assume a random sample, or make any of the distributional assumptions that often preclude statistical inferences about single‐case data. A feature that randomization tests share with parametric statistics, however, is the derivation of a p‐value. P‐values are notoriously misinterpreted and are partly responsible for the putative “replication crisis.” Behavior analysts might question the utility of adding such a controversial index of statistical significance to their methods, so it is the aim of this paper to describe the randomization test logic and its potentially beneficial consequences. In doing so, this paper will: (1) address the replication crisis as a behavior analyst views it, (2) differentiate the problematic p‐values of parametric statistics from the, arguably, more useful p‐values of randomization tests, and (3) review the logic of randomization tests and their unique fit within the behavior analytic tradition of studying behavioral processes that cut across species.
... With a device always in reach, overcoming SMT addiction might be compared to quitting smoking while holding a lit cigarette, surrounded by smokers. Moreover, current technologies are deliberately designed to maximize engagement through habit-forming "features" such as infinite scroll [87] and intermittent reinforcement schedules known to lead to more persistent behaviors [88]. ...
Purpose of Review
Individuals with attention-deficit hyperactivity disorder (ADHD) may be unusually sensitive to screen media technology (SMT), from television to mobile devices. Although an association between ADHD and SMT use has been confirmed, its importance is uncertain partly due to variability in the way SMT has been conceptualized and measured. Here, we identify distinct, quantifiable dimensions of SMT use and review possible links to ADHD to facilitate more precise, reproducible investigation.
Recent Findings
Display characteristics, media multitasking, device notifications, SMT addiction, and media content all may uniquely impact the ADHD phenotype. Each can be investigated with a digital health approach and counteracted with device-based interventions. Novel digital therapeutics for ADHD demonstrate that specific forms of SMT can also have positive effects.
Summary
Further study should quantify how distinct dimensions of SMT use relate to ADHD. SMT devices themselves can serve as a self-monitoring study platform and deliver digital interventions.
... Individuals with attentiondeficit hyperactivity disorder tend to respond more impulsively, defined broadly as increased sensitivity to immediate reinforcers, relative to their typically matched peers (Luman, Tripp, & Scheres, 2010;Murray & Kollins, 2000;Tripp & Alsop, 1999;Young, Webb, Rung, & Jacobs, 2013). Individuals with conduct disorder, psychopathy, and compulsive gamblers show increased resistance to extinction and decreased sensitivity to punishment (Budhani & Blair, 2005;Hare, 1968;Horsley, Osborne, Norman, & Wells, 2012;Matthys, van Goozen, Snoek, & van Engeland, 2004). Finally, individuals with anxiety show decreased resistance to extinction (Hagopian & Ollendick, 1994. ...
Automatically reinforced Subtype 2 self-injurious behavior (ASIB) has been characterized as showing insensitivity to competing reinforcement contingencies in the contexts of both functional analyses and in treatment using reinforcement alone (Hagopian, Rooker, &Yenokyan, 2018). One question is whether this insensitivity is specific to Subtype 2 ASIB as response class in these contexts or whether it is represents a generalized response tendency of the individual that is evident across other response classes. To examine this question, we compared responding on a single-operant task under changing reinforcement schedules for three individuals with Subtype 2 ASIB, relative to a comparison group of three individuals with socially reinforced SIB (which is characterized by sensitivity to changes in reinforcement contingencies). As hypothesized, all individuals showed sensitivity to changes in contingencies. These results provide preliminary support that the insensitivity of Subtype 2 ASIB is a property specific to that response class in these contexts rather than a generalized response tendency of the individual.
... Longer periods of time, dollars spent each day and frequency are all indicators of an at risk gambling behavior (Currie et al. 2013). A high frequency gambler (> 6 time/week) has further experimentally been found to show increased resistance to a partial reinforcement schedule compared to a low frequency gambler (< 1 time/week, Horsley et al. 2012). Whether high recreational gamblers, differed by time, show an altered subjective response to an online gambling challenge in comparison to controls has to our knowledge not been investigated. ...
Gambling in moderation is a socially acceptable behavior and over 60% of the Swedish population gambles every year. It has been seen that slot machines are one of the most addictive and problematic forms of gambling and contribute highly to an addictive behavior.
It is unclear why some individuals intensify their gambling behavior over time to extreme levels while others do not. Initial positive response of a drug or as in this case a gambling behavior, most likely influences the likelihood of continuing use in non-addicted individuals. Therefore, we wanted to investigate if recreational gamblers show an altered subjective response to an online gambling challenge, e.g. to casino gambling. The present study was designed to examine the subjective effects after an acute gambling challenge, in healthy recreational gamblers compared with non-gamblers. Eighty-two subjects participated in the study. They were challenged with an acute online slot machine gambling challenge and self-report questionnaires of mood and blood pressure were taken before and after gambling. The gamblers, and more specifically the high recreational gamblers, reported increased stimulative effects after the gambling challenge in comparison to the non-gamblers. Findings suggests that gamblers experience significantly higher arousal effects to an acute online slot machine challenge. This response may be a uniquely predictive behavior for increased risk of gambling addiction.
... Since Skinner's [69] initial insight, animal and human studies of gambling have contributed to establishing a link between reward uncertainty, dopamine, and the continuation of betting behavior despite nonreinforcement (e.g., [50,81]). For example, in a computerized human gambling task, high-frequency gamblers were shown to respond more in extinction than low-frequency gamblers when trained under partial reinforcement, but not when trained under continuous reinforcement [44]. ...
Individuals trained under partial reinforcement (PR) typically show a greater resistance to extinction than individuals exposed to continuous reinforcement (CR). This phenomenon is referred to as the PR extinction effect (PREE) and is interpreted as a consequence of uncertainty-induced frustration counterconditioning. In this study, we assessed the effects of PR and CR in acquisition and extinction in two strains of rats, the inbred Roman high- and low-avoidance (RHA and RLA, respectively) rats. These two strains mainly differ in the expression of anxiety, the RLA rats showing more anxiety-related behaviors (hence, more sensitive to frustration) than the RHA rats. At a neurobiological level, mild stress is known to elevate corticosterone in RLA rats and dopamine in RHA rats. We tested four groups of rats (RHA/CR, RHA/PR, RLA/CR, and RLA/PR) in two successive acquisition-extinction phases to try to consolidate the behavioral effects. Animals received training in a Pavlovian autoshaping procedure with retractable levers as the conditioned stimulus, food pellets as the unconditioned stimulus, and lever presses as the conditioned response. In Phase 1, we observed a PREE in lever pressing in both strains, but this effect was larger and longer lasting in RHA/PR than in RLA/PR rats. In Phase 2, reacquisition was fast and the PREE persisted in both strains, although the two PR groups no longer differed in lever pressing. The results are discussed in terms of frustration theory and of uncertainty-induced sensitization of dopaminergic neurons.
Gambling is a field that harbors both harmless recreational activities and pathological varieties that may be considered an addictive disorder. It is also a field that deserves special interest from a learning theoretical perspective, since pathological gambling represents both a pure behavioral addiction involving no ingestion of substances and behavior that exhibits extreme resistance to extinction. As the field of applied psychology of learning, or behavior analysis, espouses a bottom-up approach, the basis of understanding begins in basic research on behavioral principles. This article provides a narrative review of the field of laboratory experiments conducted to disentangle the learning processes of gambling behavior. The purpose of this review is to give an overview of learning principles in gambling that has been demonstrated under lab conditions and that may be of importance in the development of clinical applications when gambling has become a problem. Several processes, like the importance of delay and probability discounting, reinforcement without actual winning, and rule governed behavior have been experimentally verified. The common denominator appears to be that they impede extinction. Other areas, especially Pavlovian conditioning, are scarce in the literature. Our recommendations for the future would be to study Pavlovian and instrumental conditioning in interaction. Treatment programs should profit from strategies that serve to enhance extinction learning. We also conclude that online gambling should provide a promising environment for controlled research on how to limit excessive gambling, provided that the gambling companies are interested in that.
Treatment non-adherence poses a sizeable and persistent challenge to health professionals. In the US alone, it is estimated that at least $100 billion per year is spent on avoidable health care costs with an additional $230 billion per year forfeited due to lost productivity. Efforts to increase adherence have yielded mixed results. We present an adaptable, theoretical framework that uses established gamification methods coupled with a means of motivating patients using real-world rewards. The framework presented herein is implemented via user interface modifications to a clinically validated health tracking app, as well as a means of delivering video feedback for viewing a variety of potential reward outcomes.
Active school travel (AST) is an important source of physical activity for children and a conceptual understanding of AST is necessary to inform promotion efforts. The aim of this paper is to provide a conceptual analysis of AST. All currently identified AST formulations include intra-individual variables which are often recommended as intervention targets. However, existing literature lacks clarity on precisely how these intra-individual variables might shape specific AST interventions. Moreover, evaluative studies of AST interventions typically fail to specify an underpinning theory or model. To address this limitation, the Behavioural Ecological Model (BEM), not previously addressed in AST, is presented to guide this area of research. Based on specific examples, we draw attention to the role of potential antecedents and potential reinforcers of AST, as well as potential reinforcers of motorised travel. Antecedents and reinforcers may help to explain choices of school travel mode, and to inform and increase intervention options to promote AST. Consistent with the BEM, the provision of more immediate consequences, such as fun and material prizes, is an evidence-based strategy for increasing AST which is likely to be low-cost and easier to deliver than alternative interventions. This approach to the study of AST is expected to contribute to similar analyses in this and other areas of behaviour change research, and to a more useful discussion and treatment of theoretical and conceptual behavioural models.
Free-spins on slot machines introduce a salient moment of potentially large wins that might influence people to either quit or continue a gambling session. Two theoretical models make different predictions about why people quit a gambling session. From a behaviourist perspective, people quit a session when they are either satiated or the lack of rewards lead to the extinction of behaviour. Alternatively, from a behavioural-finance perspective, people quit due to the disposition effect: a general finding whereby investors tend to sell shares or other assets when the price has increased, but keep assets that have dropped in value. From the behaviourist perspective, we predict that people experience free spins as a moment of intermittent reinforcement, which should encourage them to continue gambling longer. According to the disposition effect, however, the large win would trigger risk-aversion, signalling an opportunity to “cash out” and lock-in the gain. In the present study, 188 gamblers (72 female) were randomly allocated to one of three conditions: control, early free-spins and late free-spins, in an online EGM simulation (points only). Consistent with the disposition effect, participants who received early free-spins quit earlier, placing significantly fewer bets, than those in control condition. The study suggests that free-spins, rather than being reinforcing within session, may signal an opportunity to quit early. In the discussion, however, we speculate on whether future research could demonstrate that a perceived lack of free spins in a session may keep players engaged longer.
“Delusions” are beliefs that are false and persistent. It is suggested here that these characteristics can emerge from interplays between two fundamental learning processes: (1) the allocation of attentional resources among stimuli; and (2) the effects of feedback on learning. The former of these has been operationalized in the learned irrelevance and latent inhibition paradigms; the latter in studies of the effects of persistence-training. Normally, the attentional process functions to constrain persistence-training effects so that only valid associations acquire persistence. But when persistence-training is less influenced in this way, its mechanisms can interact with a noisy environment to gradually insulate maladaptive associations from disconfirming feedback. When unchecked, these dynamics likely lead to a systematic distortion of beliefs that can become increasingly persistent regardless of their validity. Delusions are therefore predicted to tend to arise whenever the balance of (1) is weakened in favour of (2), whether by experimental manipulation, trait-related factors, cultural causes or evolutionary history. Existing evidence is consistent with the model and further implications are discussed.
Free-spins on slot machines introduce a salient moment of potentially large wins that might influence people to either quit or continue a gambling session. Two theoretical models make different predictions about why people quit a gambling session. From a behaviourist perspective, people quit a session when they are either satiated or the lack of rewards lead to the extinction of behaviour. Alternatively, from a behavioural-finance perspective, people quit due to the disposition effect: a general finding whereby investors tend to sell shares or other assets when the price has increased, but keep assets that have dropped in value. From the behaviourist perspective, we predict that people experience free spins as a moment of intermittent reinforcement, which should encourage them to continue gambling longer. According to the disposition effect, however, the large win would trigger risk-aversion, signalling an opportunity to “cash out” and lock-in the gain. In the present study, 188 gamblers (72 female) were randomly allocated to one of three conditions: control, early free-spins and late free-spins, in an online EGM simulation (points only). Consistent with the disposition effect, participants who received early free-spins quit earlier, placing significantly fewer bets, than those in control condition. The study suggests that free-spins, rather than being reinforcing within session, may signal an opportunity to quit early. In the discussion, however, we speculate on whether future research could demonstrate that a perceived lack of free spins in a session may keep players engaged longer.
Introduction: Online gambling, popular among both problem and recreational gamblers, simultaneously entails both heightened addiction risks as well as unique opportunities for prevention and intervention. There is a need to bridge the growing literature on learning and extinction mechanisms of gambling behavior, with account tracking studies using real-life gambling data. In this study, we describe the development and validation of the Frescati Online Research Casino (FORC): a simulated online casino where games, visual themes, outcome sizes, probabilities, and other variables of interest can be experimentally manipulated to conduct behavioral analytic studies and evaluate the efficacy of responsible gambling tools.
Methods: FORC features an initial survey for self-reporting of gambling and gambling problems, along with several games resembling regular real-life casino games, designed to allow Pavlovian and instrumental learning. FORC was developed with maximum flexibility in mind, allowing detailed experiment specification by setting parameters using an online interface, including the display of messages. To allow convenient and rapid data collection from diverse samples, FORC is independently hosted yet integrated with the popular crowdsourcing platform Amazon Mechanical Turk through a reimbursement key mechanism. To validate the survey data quality and game mechanics of FORC, n = 101 participants were recruited, who answered an questionnaire on gambling habits and problems, then played both slot machine and card-draw type games. Questionnaire and trial-by-trial behavioral data were analyzed using standard psychometric tests, and outcome distribution modeling.
Results: The expected associations among variables in the introductory questionnaire were found along with good psychometric properties, suggestive of good quality data. Only 6% of participants provided seemingly poor behavioral data. Game mechanics worked as intended: gambling outcomes showed the expected pattern of random sampling with replacement and were normally distributed around the set percentages, while balances developed according to the set return to player rate.
Conclusions: FORC appears to be a valid paradigm for simulating online gambling and for collecting survey and behavioral data, offering a valuable compromise between stringent experimental paradigms with lower external validity, and real-world gambling account tracking data with lower internal validity.
Mobile gambling is an emerging market in which there is evidence that some gamblers are introduced to gambling through their mobile device, and that mobile gambling does not ‘cannibalise’ participation with other forms of gambling. There is a concern that mobile gamblers face distinct risks from other forms of gambling, particularly for harmful behaviours. This paper presentation outlines a behavioural account of mobile gambling that combines both the learned characteristics of problem gambling with how individuals interact with their mobile devices. This hypothesizes that the extended gaps between plays or sessions potentially attracts extended play, even in the face of losses. We initially tested this in the laboratory using a simulated slot machine, finding that longer gaps on a gambling style of play increased the rate at which individuals gambled when they could no longer win money. To test this further we designed a simple mobile gambling app in the form of a scratchcard, and asked participants to play on the app over a period of eight to ten weeks. For the final two weeks the app was designed so that participants could not win. During this time gambling behaviour, location and the other apps the users used and intended to use before/after gambling were recorded, and measures of gambling, risk-taking and affect were taken. In total we collected the output of nearly fifty thousand gambles, finding that participants showed considerable perseverance in the face of losses; differences in gambling under extinction appeared consistent with a behavioural account of gambling.
Motivated behavior has long been studied by psychologists, ethologists, and neuroscientists. To date, many scientists agree with the view that cue and reward attraction is the product of a dopamine-dependent unconscious process called incentive salience or "wanting". This process allows the influence of multiple factors such as hunger and odors on motivational attraction. In some cases, however, the resulting motivated behavior differs from what the incentive salience hypothesis would predict. I argue that seeking behavior under reward uncertainty illustrates this situation: Organisms do not just "want" (appetite-based attraction) cues that are inconsistent or associated with reward occasionally, they "hope" that those cues will consistently predict reward procurement in the ongoing trial. Said otherwise, they become motivated to invest time and energy to find consistent cue-reward associations despite no guarantee of success (effort-based attraction). A multi-test comparison of performance between individuals trained under uncertainty and certainty reveals behavioral paradoxes suggesting that the concept of incentive salience cannot fully account for responding to inconsistent cues. A mathematical model explains how appetite-based and effort-based attractions might combine their effects.
In the Monty Hall Dilemma (MHD), three doors are presented with a prize behind one and participants are instructed to choose a door. One of the unchosen doors not containing the prize is revealed, following which the participant can choose to stay with their chosen door or switch to the other one. The optimal strategy is to switch. Herbranson and Schroeder (2010) found that humans performed poorly on this task, whereas pigeons learned to switch readily. We found that pigeons performed only slightly better than humans and that pigeons stayed nearly exclusively when staying and switching were reinforced equally and when staying was the optimal strategy (Stagner et al., 2013b). In Experiment 1 of the present research, rats were trained under these same conditions to observe if possible differences in foraging strategy would influence performance on this task. In Experiment 2, pigeons were trained in an analogous procedure to better compare the two species. We found that both species were sensitive to the overall probability of reinforcement, as both switched significantly more often than subjects that were reinforced equally for staying and switching or reinforced more often for staying. Overall, the two species performed very similarly within the parameters of the current procedure.
Various studies demonstrated that extinction training taking place shortly after the activation of the acquired fear could weaken the conditioned fear. The procedure is called post-retrieval extinction (PRE). However, from the time it emerged, it has suffered from inconsistencies in the ability of researchers to replicate the seemingly established effects. Extant literature implies that conditioned fear might be differentially sensitive to the nature of conditioned stimuli (CS) used. The aim of the present study, therefore, is threefold. First, we aimed to replicate Schiller et al. (Nature, 463, 49–53. 2010) procedure in which the PRE had produced positive results with arbitrary CSs only. Also, we examined the PRE as a function of CS type (ecological-fear-relevant (images of spider and snake) vs. arbitrary (images of yellow and blue circles)). Finally, we aimed to investigate the long-term effects of the PRE (i.e., 24 h, 15 d, and 3 mo). The study consisted of acquisition, re-activation and extinction, and re-extinction phases. Dependent measure was the recovery of fear responses as indexed by the skin conductance responses (SCRs) and arousal ratings of the participants at the last trial of the extinction and the first trial of the re-extinction. All groups showed significant acquisition and extinction patterns, compared to the other two groups (i.e., 6 h after the activating CS and without an activating stimulus) only the group that undertook extinction trials 10 min after the activating CS showed a sustained extinction. Thus, our findings provided further evidence for the robustness of the PRE paradigm in preventing the recovery of extinguished fears behaviorally, both with ecological and arbitrary stimuli.
On the basis of previous data showing (1) the dependence of the partial reinforcement extinction effect (PREE) upon the release of noradrenaline (NA) within the hippocampal formation and (2) a long-term proactive increase in intrahippocampal NA release after systemic treatment with nicotine, it was predicted that this compound would proactively enhance the PREE. The PREE was measured in rats as running speed in the straight alley after training on continuous reinforcement (CRF) or partial reinforcement (PRF) schedules of food reward, the PREE consisting in increased resistance to extinction of the running response after PRF relative to CRF training. The prediction was confirmed, largely reflecting a nicotine-induced increase in resistance to extinction in the PRF condition, in three experiments: a single injection of nicotine (0.8 mg/kg s.c.) preceding runway training and extinction at one trial a day, seven daily injections of nicotine preceding the same paradigm, and a single injection of nicotine preceding training and extinction at six trials a day. The observed behavioral changes occurred up to a month after nicotine administration, a time course similar to that seen in previous neurochemical experiments. The effects of the one- and seven-injection regimes on the PREE were statistically indistinguishable, also in agreement with previous neurochemical data.
Data are reviewed, largely from experiments in the authors'laboratory, that suggest three modes of action of systemic nicotine in producing three different types of effect upon behavior and cognitive function. (1) Preexposure of a stimulus without consequence makes it harder subsequently to form associations to that stimulus, a form of selective attention known as latent inhibition. Latent inhibition is blocked by nicotine, an effect that is apparently mediated by a nicotine-induced increase in dopamine release in the nucleus accumbens. (2) A single dose of nicotine proactively increases the partial reinforcement extinction effect measured several weeks later: that is, resistance to extinction is decreased by nicotine in animals that have been trained on a continuous reinforcement schedule, and increased in animals trained on a partial reinforcement schedule. This effect appears to be due to increased synthesis of tyrosine hydroxylase in the cell bodies of noradrenergic neurons in the locus coeruleus, followed by axonal transport to the hippocampus and increased synthesis and release of noradrenaline in that structure. (3) Nicotine improves vigilance in animals with cognitive deficits due to destruction of the forebrain cholinergic projection system, either as a consequence of excitotoxic lesions of the nuclei of origin of this system or after prolonged alcohol consumption; and also in human subjects with Alzheimer's disease (in which this system undergoes degeneration). This effect is most likely due to an action at denervated cholinergic synapses in the hippocampus and neocortex. © 1994 Wiley-Liss, Inc.
Many gamblers claim that gambling is intrinsically exciting, with money playing only a secondary role. To examine the effects of the expectancy of winning money, the authors randomly assigned 243 male college student gamblers to 1 of 6 experimental or 1 of 3 control conditions. Control participants either simply watched a videotaped horse race or they picked a horse, but without wagering; that horse later turned out to be either the winner of the race or the runner-up. Experimental participants wagered $1 on a horse for a chance of winning either USD 2, USD 7, or USD 15, with half winning and half losing their wagers. Wagering led to increased heart rates and subjective excitement as a function of the expected payoff and of winning as opposed to losing the wager. The study was replicated with 200 female college student gamblers with similar results. These findings support the notion that the excitement of gambling is tied to the expectancy of winning money.
The performance of healthy volunteer subjects on an auditory latent inhibition (LI) paradigm was assessed following administration of a single oral dose of d-amphetamine or placebo. It was predicted that a low (5 mg), but not a high (10 mg), dose of d-amphetamine would disrupt LI. The prediction was supported with left ear presentation of the preexposed stimulus only. When the preexposed stimulus was presented to the right ear the predicted pattern of findings was not obtained. It is concluded that the dopaminergic system is involved in the mediation of LI in man and it is speculated that the interaction between amphetamine dose and ear of presentation of the preexposed stimulus may reflect normally occurring dopaminergic hemisphere asymmetry.
The Drug Abuse Screening Test (DAST) was designed to provide a brief instrument for clinical screening and treatment evaluation research. The 28 self-report items tap various consequences that are combined in a total DAST score to yield a quantitative index of problems related to drug misuse. Measurement properties of the DAST were evaluated using a clinical sample of 256 drug/alcohol abuse clients. The internal consistency reliability estimate was substantial at .92, and a factor analysis of item intercorrelations suggested an unidimensional scale. With respect to response style biases, the DAST was only moderately correlated with social desirability and denial. Concurrent validity was examined by correlating the DAST with background variables, frequency of drug use during the past 12 months, and indices of psychopathology. Although these findings support the usefulness of the DAST for quantifying the extent of drug involvement within a help-seeking population, further validation work is needed in other populations and settings.
The possibility that monoaminergic neurotransmission is altered in pathological gambling was examined.
Monoamines and their metabolites were measured in CSF obtained at level L4-5 from ten pathological gamblers and seven controls.
A decrease in dopamine and an increase in 3,4-dihydroxyphenylacetic acid and homovanilic acid was found. Noradrenaline and its metabolite 3-methoxy-4-hydroxyphenylglycol was also increased but 5-hydroxytryptamine and 5-hydroxyindoleacetic acid were unchanged.
It is suggested that the function of the dopaminergic system, possibly mediating positive and negative reward, and the noradrenergic system, possibly mediating selective attention, is changed in pathological gambling.
Abnormalities in the dopaminergic reward pathways have frequently been implicated in substance abuse and addictive behaviors. Recent studies by Self and coworkers have suggested an important interaction between the dopamine D1 and D2 receptors in cocaine abuse. To test the hypothesis that the DRD1 gene might play a role in addictive behaviors we examined the alleles of the Dde I polymorphism in three independent groups of subjects with varying types of compulsive, addictive behaviors-Tourette syndrome probands, smokers and pathological gamblers. In all three groups there was a significant in the frequency of homozygosity for the DRD1 Dde I 1 or 2 alleles in subjects with addictive behaviors. The DRD1 11 or 22 genotype was present in 41.3% of 63 controls and 57.3% of 227 TS probands (P = 0.024). When 23 quantitative traits were examined by ANOVA those carrying the 11 genotype consistently had the highest scores. Based on these results, we examined the prevalence of the 11 genotype in controls, TS probands without a specific behavior, and TS probands with a specific behavior. There was a progressive, linear increase, significant at alpha < or = 0.005 for scores for gambling, alcohol use and compulsive shopping. Problems with three additional behaviors, drug use, compulsive eating and smoking were significant at alpha < or = 0.05. All six variables were related to addictive behaviors. In a totally separate group of controls and individuals attending a smoking cessation clinic, and smoking at least one pack per day, 39.3% of the controls versus 66.1% of the smokers carried the 11 or 22 genotype (P = 0.0002). In a third independent group of pathological gamblers, 55.8% carried the 11 or 22 genotype (P = 0.009 vs the combined controls). In the TS group and smokers there was a significant additive effect of the DRD1 and DRD2 genes. The results for both the DRD1 and DRD2 genes, which have opposing effects on cyclic AMP, were consistent with negative and positive heterosis, respectively. These results support a role for genetic variants of the DRD1 gene in some addictive behaviors, and an interaction of genetic variants at the DRD1 and DRD2 genes.
The Kamin blocking effect (KBE) is an established animal learning paradigm measuring selective processing, in which reduced blocking reflects allocation of greater processing resources to non-relevant information. Two KBE tasks are described below. Results from studies using the first (between-subjects) task indicate that KBE is abolished in acute schizophrenics with positive psychotic symptoms. It is also abolished in the relatives of schizophrenic subjects, although interpretation of this finding is hampered by poor performance of subjects in the control condition. The second (within-subjects) task indicated abolition of KBE in schizophrenic patients with positive psychotic symptoms. Administration of acute amphetamine to normal human subjects did not significantly disrupt performance on the first task. Whilst for the second task, although blocking was limited to placebo subjects, overall pre-exposure effects are not sufficiently strong to indicate specific drug effects.
Latent inhibition (LI) refers to a retardation of learning about the consequences of a stimulus when that stimulus has been passively presented a number of times without reinforcement. Acute positive-symptom schizophrenics, normal volunteers who score high on questionnaire measures of schizotypy and non-patients or animals treated with dopamine agonists show reduced LI. Neuroleptic drugs, such as haloperidol, administered at low doses, potentiate LI and effectively reverse disruption of LI induced by dopamine agonists in animals. However, a high dose of haloperidol, administered on its own, has been found to reduce LI. We examined the effects on LI of acute oral administration of an indirect dopamine-agonist, d-amphetamine (5 mg), and a nonselective dopamine receptor antagonist, haloperidol (5 mg), in normal male volunteers, using an associative learning task. Replicating previous reports, we found that d-amphetamine reduced LI; haloperidol also reduced LI, but only in subjects who scored low on the Psychoticism scale of the Eysenck Personality Questionnaire. In a subsequent study, no effect was found of 2 mg oral haloperidol administration on LI. The effect of 5 mg haloperidol on LI is interpreted as similar to that observed with a high dose of haloperidol in rats.
Comparative studies have implicated the nucleus accumbens (NAcc) in the anticipation of incentives, but the relative responsiveness of this neural substrate during anticipation of rewards versus punishments remains unclear. Using event-related functional magnetic resonance imaging, we investigated whether the anticipation of increasing monetary rewards and punishments would increase NAcc blood oxygen level-dependent contrast (hereafter, "activation") in eight healthy volunteers. Whereas anticipation of increasing rewards elicited both increasing self-reported happiness and NAcc activation, anticipation of increasing punishment elicited neither. However, anticipation of both rewards and punishments activated a different striatal region (the medial caudate). At the highest reward level ($5.00), NAcc activation was correlated with individual differences in self-reported happiness elicited by the reward cues. These findings suggest that whereas other striatal areas may code for expected incentive magnitude, a region in the NAcc codes for expected positive incentive value.
At the moment, there is no single conceptual theoretical model of gambling that adequately accounts for the multiple biological, psychological and ecological variables contributing to the development of pathological gambling. Advances in this area are hampered by imprecise definitions of pathological gambling, failure to distinguish between gambling problems and problem gamblers and a tendency to assume that pathological gamblers form one, homogeneous population with similar psychological principles applying equally to all members of the class. The purpose of this paper is to advance a pathways model that integrates the complex array of biological, personality, developmental, cognitive, learning theory and ecological determinants of problem and pathological gambling. It is proposed that three distinct subgroups of gamblers manifesting impaired control over their behaviour can be identified. These groups include (a) behaviourally conditioned problem gamblers, (b) emotionally vulnerable problem gamblers and (c) antisocial, impulsivist problem gamblers. The implications for clinical management are discussed.
Amphetamine can increase conditioning to poor predictors of reinforcement in selective learning tasks (e.g. latent inhibition, LI). In the present study, a noise stimulus was contiguous with footshock or presented at a trace interval. A flashing light background stimulus was used to measure contextual conditioning. Experiment 1 used 1.5 mg/kg and 6 mg/kg dl-amphetamine. Experiments 2 and 3 used 0.5 mg/kg and 1.5 mg/kg d-amphetamine. Unconditioned stimuli parameters (intensity, number, duration) were also manipulated from one experiment to the next. Amphetamine consistently increased conditioning to the background stimulus, and increased conditioning to the trace stimulus at higher footshock intensity (Experiment 3). Thus, amphetamine increased conditioning only to relatively uninformative predictors. The effect on conditioning to trace conditioned stimuli depended on the level of reinforcer but increased conditioning to background did not. Throughout, there was no effect of amphetamine on conditioning of the contiguous stimulus. Thus, the results did not simply arise because amphetamine increased conditioning under any condition in which conditioning without amphetamine was poor. The results are discussed in terms of amphetamine effects on breadth of attention and LI to context.
This study investigates the effects of video lottery players' expectancies of winning on physiological and subjective arousal.
Participants were assigned randomly to one of two experimental conditions: high and low winning expectancies.
Participants played 100 video lottery games in a laboratory setting while physiological measures were recorded. Level of risk-taking was controlled.
Participants were 34 occasional or regular video lottery players. They were assigned randomly into two groups of 17, with nine men and eight women in each group.
The low-expectancy group played for fun, therefore expecting to win worthless credits, while the high-expectancy group played for real money.
Players' experience, demographic variables and subjective arousal were assessed. Severity of problem gambling was measured with the South Oaks Gambling Screen. In order to measure arousal, the average heart rate was recorded across eight periods.
Participants exposed to high as compared to low expectations experienced faster heart rate prior to and during the gambling session. According to self-reports, it is the expectancy of winning money that is exciting, not playing the game.
Regardless of the level of risk-taking, expectancy of winning is a cognitive factor influencing levels of arousal. When playing for fun, gambling becomes significantly less stimulating than when playing for money.
The present experiment was conducted to investigate the effects that changes in reinforcement schedule have on the persistence of learned responses. Human subjects learned two simple tasks concurrently, both tasks being under either continuous reinforcement (CRF) or partial reinforcement (PRF). After 50 acquisition trials on both tasks, half the subjects in each schedule condition received an additional 50 acquisition trials with the same reinforcement schedules on the two tasks. The remaining subjects received 50 additional trials with the opposite reinforcement schedule on both tasks. All subjects then received 50 extinction trials on both tasks. The extinction data were biphasic, consisting of a short-term phase of declining performance in which group differences were clear, followed by a long-term phase in which the groups converged to a uniform high level of persistence. A conventional partial reinforcement effect was observed during the short-term phase, but only in terms of the most recently experienced schedule, that is, the first schedule experienced appeared to have no effect upon persistence, contrary to some current theories of the partial reinforcement effect. The role of task demands in this type of research is discussed.
This paper reviews the research literature on excessive and persistent gambling with particular emphasis on the reasons why such behaviour has come to be classified among the addictions. The characteristics of gamblers who seek help from mental health agencies are discussed in relation to the diagnostic criteria for ‘pathological gambling’ given in DSM III-R.5Although there have been few controlled treatment evaluations the range of therapeutic approaches employed in Australia, the U.S.A. and the U.K. are reviewed. A variety of theoretical models have been proposed to explain the psychological and physiological processes that may underlie the progression of this behavior from an infrequent leisure habit to a costly, all-engrossing, addictive-like preoccupation. These models are critically reviewed in the light of existing empirical findings. The evidence that excessive gambling shows features of dependence despite the absence of a psychoactive agent is evaluated. The concluding section of the paper explores the potential theoretical and clinical benefits inherent in classifying this behavioural excess as an addiction.
As access to gambling increases there is a corresponding increase in the frequency of addiction to gambling, known as pathological gambling. Studies have shown that a number of different neurotransmitters are affected in pathological gamblers and that genetic factors play a role. Polymorphisms at 31 different genes involved in dopamine, serotonin, norepinephrine, GABA and neurotransmitters were genotyped in 139 pathological gamblers and 139 age, race, and sex-matched controls. Multivariate regression analysis was used with the presence or absence of pathological gambling as the dependent variable, and the 31 coded genes as the independent variables. Fifteen genes were included in the regression equation. The most significant were the DRD2, DRD4, DAT1, TPH, ADRA2C, NMDA1, and PS1 genes. The r2 or fraction of the variance was less than 0.02 for most genes. Dopamine, serotonin, and norepinephrine genes contributed approximately equally to the risk for pathological gambling. These results indicate that genes influencing a range of brain functions play an additive role as risk factors for pathological gambling. Multi-gene profiles in specific individuals may be of assistance in choosing the appropriate treatment.
66 college students were conditioned to a light followed by a puff of air to the cornea. Training occurred under three different conditions: Group I was given 100% reinforcement for 96 trials, the light always being followed by the puff, followed by 24 extinction trials. Group II was given 50% reinforcement for 96 trials, the light being followed by the puff in half the trials, followed by 24 extinction trials. Group III was given 100% reinforcement for 48 trials, with 48 interspersed rest intervals where non-reinforced trials occurred in Group II, followed by 24 extinction trials. The results justify the following conclusions: (1) There are no differences in the acquisition of CR's, measured by frequency and magnitude, under the three procedures. This is evidence that non-reinforced trials do not always result in significant decrements (Group II). It also points to an advantage of spaced trials over an equal number of massed trials (Groups I and III). (2) There are differences in the extinction of the CR's between Group II (50% reinforcement) and Groups I and III (100% reinforcement). Group II responds at a significantly higher level over the 24 extinction trials than Groups I and III. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
This study reports on the direct observations of customers in two U.K. betting offices gambling on horse and dog races. These observations revealed that bets were more frequently placed in the last minutes just prior to the start (the OFF), and that this was caused by high-frequency gamblers (customers who had eight or more bets in a session) consistently placing their bets in the last two minutes prior to the OFF. Low-frequency gamblers (three or fewer bets/session) avoided this time period placing their bets earlier, or after the OFF, i.e., on a later race. It was argued that the betting behavior of the "gamblers" could not be explained either in terms of "skillful betting" or solely in terms of variable ratio schedules but was more adequately accounted for in terms of an interval schedule. It was further suggested that time-based schedules might be of heuristic value in generally understanding persistence at gambling while losing.
The partial reinforcement extinction effect (PREE) refers to the increased resistance to extinction observed in animals trained on a partial reinforcement (PR) schedule compared with those trained on a schedule of continuous reinforcement (CR). It has been suggested that the PREE is dependent upon the integrity of the septo-hippocampal system, but recent evidence has indicated that the role originally proposed for the lateral septal nucleus may in fact be subserved by the nucleus accumbens. Experiment I therefore tested the effects of electrolytic lesions of the nucleus accumbens on the PREE. These lesions abolished the PREE, the abolition resulting from a decreased rate of extinction in the lesion CR rats coupled with an increased rate of extinction in the PR rats. These results clearly implicate the nucleus accumbens in the development of the PREE, and suggest that theoretical models of the PREE based simply upon consideration of septohippocampal interactions need radical revision. The lesion also enhanced running speeds in acquisition in both the CR and the PR groups. Experiment II therefore assessed spontaneous locomotor activity and the locomotor response to amphetamine challenge at two doses. The lesion produced no increase in spontaneous locomotion; an enhanced increase in response to 1 mg/kg amphetamine; and no changes in the stereotyped behaviours induced by 10 mg/kg amphetamine.
The in vivo neurochemical profile of recently synthesized dopamine (DA) uptake inhibitors (Lu 19-005, Lu 17-133 and GBR 12.921) is described. The antidepressant, nomifensine, as well as another typical DA uptake inhibitor, methylphenidate, was also tested with the microdialysis technique. Most of the new DA uptake inhibitors induced a gradual dose- and time-dependent accumulation of extracellular DA with a weak influence on DA metabolites, similar to that of methylphenidate. Nomifensine, however, caused a DA overflow during the first hour after injection. This was distinguishable from the effect of other uptake inhibitors but comparable to amphetamine. The moderate increase of DOPAC induced by nomifensine compared to the marked decrease produced by amphetamine corroborates reports that the DA 'release' induced by these drugs is mediated by different mechanisms, originating from different intracellular storage pools of DA. The fact that nomifensine can be distinguished from other uptake inhibitors shows clearly that evaluation of dynamic changes in transmitter overflow provides information pertinent to the overall neurochemical characterization of a drug.
Two experiments investigated the effects of d-amphetamine (1 mg/kg) on the partial reinforcement extinction effect (PREE) in an operant chamber using a discrete multitrial procedure. Experiment 1 used a random 50% partial reinforcement (PRF) schedule. Experiment 2 used two 40% PRF schedules: one schedule maximized the number of nonreinforced trials preceding any given reinforced trial (maximum N-length of four) and the second maximized the number of N-R transitions (N-length of one). In both experiments, the continuously reinforced (CRF) animals received a reward on every trial. The PREE, i.e., increased resistance to extinction of PRF as compared to CRF animals, was obtained in the random 50% PRF and the schedule maximizing N-length in both the placebo and amphetamine-treated animals. Both drug and no-drug animals failed to exhibit PREE on the schedule maximizing N-R transitions. These results show that on a PRF schedule with short intertrial intervals, amphetamine-treated animals are not impaired in their capacity to learn sequences of events and to associate the outcomes of preceding trials with subsequent consequences.
Three experiments examined the effects of d-amphetamine (1 mg/kg) administration on the partial reinforcement extinction effect (PREE) using a multitrial procedure. Two groups of rats were trained to run in a straight alley. The continuously reinforced (CRF) group received food reward on every trial. The partially reinforced (PRF) group was rewarded on a quasi-random 50% schedule. All animals were then tested in extinction. Experiments 1 and 2 used 6 trials/day with an intertrial interval (ITI) of 5 min. In Experiment 1 the drug was administered only during acquisition, whereas in Experiment 2 it was administered throughout acquisition and extinction. Experiment 3 used 3 trials/day with a 20 min ITI. The drug was administered throughout acquisition and extinction. In all three experiments, amphetamine-treated animals showed a normal PREE, i.e., increased resistance to extinction in PRF as compared to CRF animals. These results stand in marked contrast to the amphetamine-induced abolition of the PREE with 1 trial/day procedure.
In the latent inhibition (LI) paradigm, nonreinforced preexposure to a stimulus retards subsequent conditioning to that stimulus. Three experiments investigated the effects of acute amphetamine administration on LI in rats. Experiments 1 and 3 used a conditioned emotional response (CER) procedure and Experiment 2 used two-way active avoidance procedure. Experiments 1 and 2 showed that, in both the CER and avoidance procedures, 1.5 mg/kg dl-amphetamine administered either in the preexposure or the conditioning stage alone did not disrupt LI. In contrast, amphetamine administered in both of the stages abolished LI. Experiment 3 showed that the abolition of LI was obtained when the preexposure and conditioning were given 24 hr apart but not when the two stages were given in one session.
Two groups of rats were trained to run in a straight alley. The continuously reinforced (CRF) group received a food reward on every trial. The partially reinforced (PRF) group was rewarded on a quasi-random 50% schedule. d-Amphetamine 1 mg/kg was administered to PRF animals in acquisition in a 2 X 2 design, i.e., drug-no drug on reinforced trials and drug-no drug on nonreinforced trials. In four CRF groups, the drug was administered in the same sequence as in the PRF groups. Following acquisition, all animals were given 4 days of CRF retraining and tested in extinction. No drug was given in retraining and extinction. The PREE, i.e., increased resistance exhibited by PRF animals as compared to CRF animals, was obtained in groups which received placebo on all acquisition trials or amphetamine on rewarded trials and placebo on nonrewarded trials. The PREE was abolished when amphetamine was administered throughout the acquisition trials or on nonrewarded trials, irrespective of drug treatment on rewarded trials.
High-(N = 22) and low-(N = 22) frequency gamblers were subjected to provocation with gambling or neutral stimuli prior to playing a poker machine. All Ss used a minimum of AS$3 of their own money and played a machine currently in use in local clubs with a maximum major payout of AS$100. HR and subjective measures of arousal were taken throughout. Neither provocation condition resulted in changes from baseline arousal in either group. Playing was associated with increases in arousal in both groups, but significantly greater arousal was shown by high-frequency players.
The CAGE questionnaire, a new brief alcoholism screening test, was administered to all patients (N = 366; 39% alcoholic) admitted to psychiatric service over a one year period. The authors indicate that the CAGE questionnaire is not a sensitive alcoholism detector if a four item positive response is the criterion; however, if a two or three item criterion is used, it becomes a viable rapid alcoholism screening technique for large groups.
In the blocking paradigm, prior training to one conditioned stimulus (CSA) blocks the ability to attend to a second conditioned stimulus (CSB) when the two form a compound (CSAB) in subsequent training. Blocking is an associative process by which animals learn to ignore CSB because it contains no new information regarding the reinforcing event. Experiment 1 showed that d-amphetamine disrupted rats' ability to ignore the irrelevant CSB: The animals responded equally to both elements of the CSAB compound following five dialy administrations of 4 mg/kg d-amphetamine. In Experiment 2 the disruption of blocking by d-amphetamine was eliminated by concomitant administration of 0.02 mg/kg haloperidol. These results are consistent with previous research showing that d-amphetamine disrupts rats' ability to ignore repeated presentations of a single nonreinforced stimulus in the latent inhibition paradigm. The inability of amphetamine-treated animals to ignore one element of a dual-element compound bears some resemblance to selective attention deficits seen among schizophrenic patients.
Latent inhibition (LI) is an attentional process by which animals learn to ignore a stimulus that is repeatedly presented without reinforcement. This ability to tune out a motivationally irrelevant stimulus is disrupted by pharmacological manipulations producing hyperdopaminergic states. In Experiment I, LI was disrupted following five daily administrations of 4 mg/kg d-amphetamine. In Experiment II the disruptive effects of d-amphetamine were eliminated by concomitant administration of chlorpromazine. Experiment III showed that LI could also be disrupted with 1 mg/kg d-amphetamine coupled with dopamine receptor supersensitivity produced by prolonged pretreatment with haloperidol. These data suggest that pharmacological disruption of LI may provide an animal analogue of the defective stimulus filtering thought to characterize at least some forms of schizophrenia.
Latent inhibition (LI) is a cognitive process whereby repeated exposure of a stimulus without consequence impedes the formation of subsequent associations with that stimulus. A number of studies in the rat have reported that LI is impaired by moderate systemic doses of amphetamine, an effect believed to be mediated via dopamine (DA) release in the nucleus accumbens. We and others have reported that nicotine has a selective effect in releasing DA in the accumbens rather than the caudate nucleus. We have therefore examined the ability of nicotine to disrupt LI, using a conditioned emotional response paradigm. Pre-exposure of a tone stimulus impaired subsequent conditioning between that stimulus and mild footshock, as indexed by suppression of licking by the tone subsequently presented alone. This LI effect was prevented, by an effect confined to the pre-exposed group, by doses of 0.4 or 0.6 mg/kg nicotine SC, which are accumbens selective, given before pre-exposure and before conditioning. The effect of nicotine in disrupting LI was prevented by prior administration of haloperidol at a dose (0.5 mg/kg) reported to reverse the disruptive effect of amphetamine on LI. Although the amphetamine effect requires two administrations, the effect of two administrations of nicotine was reproduced by a single dose of nicotine given before conditioning, but not by a single dose before pre-exposure. The results are discussed in relation to studies in human control and schizophrenic subjects, which suggest that increased DA activity in humans is also associated with impaired LI.(ABSTRACT TRUNCATED AT 250 WORDS)
A heuristic model to account for the development and maintenance of problem gambling is provided with the aim of directing clinical management and future research. Previous explanations of problem gambling have been limited in two main ways. Firstly, the models have been primarily descriptive, and secondly they have generally lacked clinical value. Most explanations have ignored the mechanisms through which this behaviour becomes problematic, and have not identified the relationships between different variables.
Pathological gambling has been termed both the 'pure' and the 'hidden' addiction. 'Pure' because it is not associated with the intake of any addicting substance, and 'hidden' because it is an extension of a common, socially accepted behaviour. The Taq A1 variant of the human DRD2 gene has been associated with drug addiction, some forms of severe alcoholism, and other impulsive, addictive behaviours. We have sought to determine if there is a similar association with pathological gambling. A total of 222 non-Hispanic Caucasian pathological gamblers from multiple sites across the US participated in the study. Of these 171 donated a sample of blood, 127 filled out several questionnaires, and 102 did both. Of the 171 pathological gamblers 50.9% carried the D2A1 allele versus 25.9% of the 714 known non-Hispanic Caucasian controls screened to exclude drug and alcohol abuse, p < 0.00000001, odds ratio (OR) = 2.96. For the 102 gamblers who filled out the questionnaires, 63.8% of those in the upper half of the Pathological Gambling Score (more severe) carried the D2A1 allele (OR versus controls = 5.03), compared to 40.9% in the lower half (less severe). Of those who had no comorbid substance abuse, 44.1% carried the D2A1 allele, compared to 60.5% of those who had comorbid substance abuse. Forty-eight controls and 102 gamblers completed a shorter version of the Pathological Gambling Score. Of the 45 controls with a score of zero, 17.8% carried the D2A1 allele. Of the 99 gamblers with a score of 5 or more, 52.5% carried the D2A1 allele (chi 2 = 15.36, p = 0.00009). These results suggest that genetic variants at the DRD2 gene play a role in pathological gambling, and support the concept that variants of this gene are a risk factor for impulsive and addictive behaviours.
A Spanish sample consisting of 68 Caucasian pathological gambling patients (47 males and 21 females) and 68 unaffected controls were screened by the molecular analysis of a functional DNA polymorphism in the locus for the D4 dopamine receptor gene. Our results are consistent with the existence of a significant association between genetic variants at a DRD4 gene polymorphism and pathological gambling (chi 2 = 11.82; P = 0.037). This association seems to be sex-influenced, since there was no significant association when only males were considered (chi 2 = 9.45; P = 0.09), but there was a more significant association if we only considered female subjects (chi 2 = 8.73; P = 0.033). Individuals with the longest allele (D7) were the most frequent in affected females (chi 2 = 4.50; P = 0.033). This work provides a new evidence of the implication of the dopaminergic reward pathways, now through the involvement of DRD4, in the aetiology of this impulsive disorder.
Prior studies have reported an association between the presence of the 7 repeat allele of the 48 bp repeat polymorphism of the third cytoplasmic loop of the dopamine D4 receptor gene (DRD4) and novelty seeking behaviors, attention deficit hyperactivity disorder (ADHD), Tourette syndrome (TS), pathological gambling, and substance abuse. However, other studies have failed to replicate some of these observations. To determine whether we could replicate these associations we genotyped 737 individuals from four different groups of control subjects, and 707 index subjects from four different groups of impulsive, compulsive addictive behaviors including substance abuse, pathological gambling, TS, and ADHD. Chi-square analysis of those carrying the 7 allele versus non-7 allele carriers was not significant for any of the groups using a Bonferroni corrected alpha of.0125. However, chi-square analysis of those carrying any 5 to 8 allele versus noncarriers was significant for pathological gambling (p <.0001), ADHD (p </=.01) and the total index group (p </=.0004). When the comparison included all 7 alleles the results were significant for gamblers (p <.0001), TS (p </=.003), ADHD (p </=.003), and the total group (p </=.0002). There was a significant increase in the frequency of heterozygosity versus homozygosity for all alleles for pathological gamblers (p </=.0031) and the total index group (p </=.0015), suggesting that heterosis played a role. In the substance abuse subjects a quantitative summary variable for the severity of drug dependence, based on the Addiction Severity Index, showed that the scores varied by increasing severity across the following genotypes: 44 </= heterozygotes </= 77 </= 22. Studies of other quantitative traits indicated an important role for the 2 allele and the 22, 24, and 27 genotypes. All studies indicated that the role of the DRD4 gene in impulsive, compulsive, addictive behaviors is more complex than a sole focus on the 7 versus non-7 alleles.
NMDA receptors (NMDARs) are highly calcium-permeable and are negatively regulated by intracellular calcium during prolonged exposure to agonist. We have investigated whether calcium-mediated feedback occurs during transient exposure to glutamate during single synaptic events. Examination of miniature EPSCs (mEPSCs) indicated that the decay kinetics of the NMDAR component was markedly slowed by the intracellular perfusion of exogenous calcium buffers (BAPTA or Fluo-3). In contrast, the AMPA receptor component of the miniature EPSC was unaffected. Slow on-rate calcium buffers, such as EGTA, did not alter kinetics of the NMDAR component of the mEPSC. Addition of exogenous fast calcium buffers did not slow the decay kinetics of glutamate-evoked currents mediated by NR1/NR2A heteromers expressed in HEK 293 cells, suggesting that the effect we observed in neurons may be specific to processes associated with synaptically activated receptors. Trial-to-trial amplitude variability of miniature calcium transients mediated by NMDARs increased with the injection of exogenous calcium buffers, suggesting that the amplitude of synaptic calcium transients are maintained at a rather constant level by a calcium-mediated feedback mechanism.
Neural responses accompanying anticipation and experience of monetary gains and losses were monitored by functional magnetic resonance imaging. Trials comprised an initial "prospect" (expectancy) phase, when a set of three monetary amounts was displayed, and a subsequent "outcome" phase, when one of these amounts was awarded. Hemodynamic responses in the sublenticular extended amygdala (SLEA) and orbital gyrus tracked the expected values of the prospects, and responses to the highest value set of outcomes increased monotonically with monetary value in the nucleus accumbens, SLEA, and hypothalamus. Responses to prospects and outcomes were generally, but not always, seen in the same regions. The overlap of the observed activations with those seen previously in response to tactile stimuli, gustatory stimuli, and euphoria-inducing drugs is consistent with a contribution of common circuitry to the processing of diverse rewards.
As access to gambling increases there is a corresponding increase in the frequency of addiction to gambling, known as pathological gambling. Studies have shown that a number of different neurotransmitters are affected in pathological gamblers and that genetic factors play a role. Polymorphisms at 31 different genes involved in dopamine, serotonin, norepinephrine, GABA and neurotransmitters were genotyped in 139 pathological gamblers and 139 age, race, and sex-matched controls. Multivariate regression analysis was used with the presence or absence of pathological gambling as the dependent variable, and the 31 coded genes as the independent variables. Fifteen genes were included in the regression equation. The most significant were the DRD2, DRD4, DAT1, TPH, ADRA2C, NMDA1, and PS1 genes. The r(2) or fraction of the variance was less than 0.02 for most genes. Dopamine, serotonin, and norepinephrine genes contributed approximately equally to the risk for pathological gambling. These results indicate that genes influencing a range of brain functions play an additive role as risk factors for pathological gambling. Multi-gene profiles in specific individuals may be of assistance in choosing the appropriate treatment.
With most Western countries expanding the availability of gambling facilities in recent decades, considerable research interest has developed in those people who develop problematic levels of gambling. In the recent decade, a large body of research has been conducted into the determinants of gambling behavior in an attempt to understand this complex social and psychological problem. Research has varied in its nature from investigating underlying biological, psychological, or social factors that are hypothesized to contribute to gambling behavior. Evidence now exists that biological, psychological, and social factors are all relevant to the development of problematic levels of gambling. However, the theoretical explanation for gambling has lagged behind the advances in empirical work in recent years. The purpose of the current paper is to provide a review of the major research findings in the area of gambling and propose a biopsychosocial model that integrates diverse areas of research. The model described is empirically derived, and it is hoped it will stimulate future research work that investigates not only individual factors and their relationship to gambling, but also the interactions between different variables.
The partial reinforcement extinction effect (PREE) was studied in human subjects. It has been suggested that the PREE depends on neural mechanisms critical to the cognitive dysfunction which underlines acute schizophrenia. We therefore predicted that the PREE should be reduced, through decreased resistance to extinction in the partial reinforcement (PR) condition, in various types of individual: (a) healthy volunteers given low doses of oral amphetamine; (b) those in the acute (but not chronic) phase of a schizophrenic illness and; (c) healthy volunteers with high scores on personality measures of schizotypy. Despite obtaining robust demonstrations of PREE in all experiments, none of these predictions were confirmed. A single, low dose, of amphetamine had no effect on either continuous reinforcement (CR) or partial reinforcement (PR). Acute and chronic schizophrenic patients showed a reduced PREE compared to controls. However this was due to increased resistance to extinction in the CR groups. Finally, high schizotypy scores were associated with greater PREE, attributable to both decreased extinction in the CR condition and increased extinction in the PR condition. The results of these experiments on human PREE provide no support that PREE is a valid paradigm with which to explore the cognitive dysfunction underlying schizophrenia.
A number of lines of evidence suggest that dopamine might play a role in stimulus selection, the process whereby specific cues are selected to guide action.
In order further to define the potential role for dopamine in stimulus selection, the present series of studies examined whether dopaminergic drugs modulate overshadowing, a paradigm that involves stimulus selection in rats. Overshadowing is where preferential learning occurs to one (usually the more salient) element of a stimulus compound.
Overshadowing was measured in rats using a thirst motivated conditioned emotional response paradigm (CER). Two simultaneously presented stimuli (light and tone) were paired with an aversive unconditioned stimulus (mild footshock); overshadowing is observed when learning to the less salient stimulus is weaker than learning to the same stimulus when it is conditioned alone.
d-Amphetamine sulphate (1 mg/kg, IP) was found selectively to disrupt overshadowing, without affecting the CER in control animals. The dopamine (DA) D(2) receptor antagonists, haloperidol (0.2 mg/kg, IP) or raclopride (0.5 mg/kg, IP), failed to reverse amphetamine-induced disruption of overshadowing. In contrast, the selective DA D(1) antagonist SCH 23390 (0.05 mg/kg, IP) reversed amphetamine-induced disruption of overshadowing. The partial DA D(1) agonist SKF 38393 (5 mg/kg, IP) was found to abolish overshadowing when given alone.
These data indicate a modulatory role for the DA D(1) receptor in the expression of stimulus selection and suggest that the DA D(1) receptor might play a role in salience allocation aspects of learning.
Over the past several decades, and particularly during the last 10 to 15 years, there has been a rapid increase in the accessibility of legalized gambling in the United States and other parts of the world. Few studies have systematically explored the relationships between patterns of gambling and health status. Existing data support the notion that some gambling behaviors, particularly problem and pathological gambling, are associated with nongambling health problems. The purpose of this article is to provide a perspective on the relationship between gambling behaviors and substance use disorders, review the data regarding health associations and screening and treatment options for problem and pathological gambling, and suggest a role for generalist physicians in assessing problem and pathological gambling. A rationale for conceptualization of pathological gambling as an addictive disorder and a model proposing stress as a possible mediating factor in the relationship between gambling and health status are presented. More research is needed to investigate directly the biological and health correlates associated with specific types of gambling behaviors and to define the role for generalist physicians in the prevention and treatment of problem and pathological gambling.
The theoretical properties ascribed to the various fractional anticipatory goal reactions (fractional anticipatory reward, fractional anticipatory punishment) are extended to include a fractional anticipatory frustration response. The latter reaction is assumed to have both motivating and inhibitory properties which are amenable to experimental verification. Several relevant studies are analyzed.
Reports an error in the original article by Donald J. Lewis (Psychological Bulletin, 57, 1-28). The figure in the sixth line of page 19 has the incorrect percentage listed. The correct number is given here. (The following abstract of this article originally appeared in record ##1960-06795-001.) Available studies concerned with the effects of partial reinforcement on extinction have so far failed to uncover parametric laws. Though the studies cited include a large number of variables only a few investigators have been concerned with how one variable relates to another along the entire range of both variables. The foregoing research strategy is necessary in order to be able to describe the desired parametric laws.
This experiment examined the effects of 0.5 and 1.5 mg/kg doses of amphetamine (AMP) in male Wistar rats, on conditioning to a contextual stimulus that for half the animals has been pre-exposed, in an appetitive conditioning procedure. Amphetamine was administered during both pre-exposure (3 days) and acquisition (15 days). Latent inhibition (LI, reduced conditioning in pre-exposed relative to non-pre-exposed rats) was seen in controls but not at either AMP dose. This abolition of LI was seen under AMP at two levels of responding in acquisition and confirmed in drug free extinction. It suggests that, like conditioning to discrete stimuli, conditioning to contextual stimuli is subject to LI and can be disrupted by AMP.