http://linkinghub.elsevier.com/retrieve/pii/S0376871611000494

Rationale: Impulsivity is implicated in drug dependence. Recent studies show problems with alcohol and opioid dependence are associated with rapid discounting of the value of delayed outcomes. Furthermore, discounting may be particularly steep for the drug of dependence. Objectives: We determined if these findings could be extended to the behavior of cigarette smokers. In particular, we compared the discounting of hypothetical monetary outcomes by current, never, and ex-smokers of cigarettes. We also examined discounting of delayed hypothetical cigarettes by current smokers. Methods: Current cigarette smokers ( n =23), never-smokers ( n =22) and ex-smokers ( n =21) indicated preference for immediate versus delayed money in a titration procedure that determined indifference points at various delays. The titration procedure was repeated with cigarettes for smokers. The degree to which the delayed outcomes were discounted was estimated with two non-linear decay models: an exponential model and a hyperbolic model. Results: Current smokers discounted the value of delayed money more than did the comparison groups. Never- and ex-smokers did not differ in their discounting of money. For current smokers, delayed cigarettes lost subjective value more rapidly than delayed money. The hyperbolic equation provided better fits to the data than did the exponential equation for 74 out of 89 comparisons. Conclusions: Cigarette smoking, like other forms of drug dependence, is characterized by rapid loss of subjective value for delayed outcomes, particularly for the drug of dependence. Never- and ex-smokers could discount similarly because cigarette smoking is associated with a reversible increase in discounting or due to selection bias.

78ATM money management-based intervention decreased delay discounting. 78ATM intervention decreased cocaine use over time. 78Change in delay discounting was related to change in cocaine abstinence. 78Monetary Choice Questionnaire scores were reliable in psychiatric patient sample.

Persistent dose-related cognitive decrements have been reported in 28-day abstinent heavy marijuana (MJ) users. However, the neural substrates of these decrements in cognitive performance are not known. This study aimed to determine if 25-day abstinent MJ users show persistent dose-related alterations in performance and brain activity using PET H 2 15O during the Iowa Gambling Task-IGT (a decision-making task). Eleven heavy MJ users and 11 non-drug users participated. The MJ group resided in an inpatient research unit at the NIH/NIDA-IRP for 25 days prior to testing to ensure abstinence. A dose-related association was found between increased MJ use and lower IGT performance and alterations in brain activity. The MJ group showed greater activation in the left cerebellum and less activation in the right lateral orbitofrontal cortex (OFC) and the right dorsolateral prefrontal cortex (DLPFC) than the Control group. When the MJ group was divided into Moderate (8–35 joints/week) and Heavy users (53–84 joints/week), the Heavy MJ group showed less activation in the left medial OFC and greater activation in the left cerebellum than the Moderate group. However, brain activity and task performance were similar between the Moderate MJ users and the Control group, suggesting a “threshold effect”. These preliminary findings indicate that very heavy users of MJ have persistent decision-making deficits and alterations in brain activity. Specifically, the Heavy MJ users may focus on only the immediate reinforcing aspects of a situation (i.e., getting high) while ignoring the negative consequences. Thus, faulty decision-making could make an individual more prone to addictive behavior and more resistant to treatment. Finally, it is unclear if these neurologic findings will become progressively worse with continued heavy MJ use or if they will resolve with abstinence from MJ use.

The anterior cingulate cortex (ACC) and lateral prefrontal (LPFC) cortex are brain regions important to executive cognitive functions (ECF). We determined ACC and LPFC function in 23-day abstinent cocaine abusers using positron emission tomography (PET H(2)(15)O) during performance of a modified version of the Stroop Task. Cocaine abusers showed less activation than non-drug-using comparison subjects in the left ACC and the right LPFC and greater activation in the right ACC. Average amount of cocaine used per week was negatively correlated with activity in the rostral ACC and right LPFC. Disruption of ECF in substance abusers could interfere with attempts to stop drug use and undermine treatment. Since impairment in ECF may be a common feature of various neuropsychiatric disorders, these findings have applicability beyond the neurobiology of addiction.

Crack cocaine use is more associated with impulsivity and a propensity to take risks than heroin use. yet no studies have examined this relationship in the absence of acute drug effects. The current study examined impulsivity (using the Delay Discounting Task) and risk-taking propensity (using the Balloon Analogue Risk Task) across independent groups of primary crack cocaine users with minimal heroin use (n = 16) and primary heroin users with minimal crack cocaine use (n = 11) in residential treatment, with all participants drug abstinent during participation. Crack cocaine users evidenced greater levels of impulsivity and risk-taking propensity, with only the difference in impulsivity persisting after controlling for age and gender. These data hold potential theoretical importance in understanding differences between crack cocaine and heroin users, as the findings cannot be attributed solely to acute pharmacological drug effects.

Rationale There is converging evidence for impairments in decision-making in chronic substance users. In the light of findings that substance abuse is associated with disruptions of the functioning of the striato halamo rbitofrontal circuits, it has been suggested that decision-making impairments are linked to frontal lobe dysfunction. We sought to investigate this possibility using functional neuroimaging. Methods Decision-making was investigated using the Cambridge Risk Task during H 2 15 O PET scans. A specific feature of the Risk Task is the decisional conflict between an unlikely high reward option and a likely low reward option. Four groups, each consisting of 15 participants, were compared: chronic amphetamine users, chronic opiate users, ex-drug users who had been long-term amphetamine/opiate users but are abstinent from all drugs of abuse for at least 1 year and healthy matched controls without a drug-taking history. Results During decision-making, control participants showed relatively greater activation in the right dorsolateral prefrontal cortex, whereas participants engaged in current or previous drug use showed relatively greater activation in the left orbitofrontal cortex. Conclusion Our results indicate a disturbance in the mediation by the prefrontal cortex of a risky decision-making task associated with amphetamine and opiate abuse. Moreover, this disturbance was observed in a group of former drug users who had been abstinent for at least 1 year.

Objective Previously, we reported that opiate users enrolled in methadone treatment made 'risky' choices on a decision-making task following a loss of points compared with heroin users and healthy volunteers. One possible explanation for this behaviour is that methadone users were less sensitive to punishment on immediately preceding unsuccessful trials. Methods We sought to explore this finding from a neural perspective by performing a post hoc analysis of data from a previous H

In four experiments, we compared the effects of delay, probability, and monetary amount on the subjective value of gains and losses. For delayed gains, smaller amounts were discounted more steeply than larger amounts, whereas the opposite pattern was observed with probabilistic gains. For both delayed and probabilistic losses, however, amount had much smaller and less reliable effects on discounting. Taken together, the pattern of differential magnitude effects leads to delayed gains' being discounted significantly more steeply than delayed losses, but only at smaller amounts, whereas probabilistic gains are discounted significantly more steeply than probabilistic losses, but only at larger amounts. Even though the same hyperbola-like function described both individual and group discounting of delayed and probabilistic gains and losses, the present findings suggest that different processes are involved in discounting positive and negative outcomes. Raw data may be downloaded from www.psychonomic.org/archive.

Alcoholism is characterized by impaired decision-making (i.e., choosing intoxication in the face of mounting negative consequences). This impairment may involve a reduced brain response to the negative consequences of behavior, which supports an inclination to engage in risky behaviors. The feedback error-related negativity (F-ERN) is hypothesized to reflect the valence attached to the negative consequences of behavior. Performance on the Balloon Analogue Risk Task (BART) measures risk-taking propensity. We recorded F-ERNs during the BART and during a BART simulation, where individuals observed the rewards and consequences of (someone else's) BART performance. EEGs were recorded on 22 actively drinking, treatment-na ve alcoholics during the BART and BART simulation. F-ERNs were measured and their association with psychological and alcohol use measures was examined. F-ERNs over fronto-central electrode sites were observed to balloon pops in the BART and BART simulation. F-ERNs during the BART were more than twice the amplitude of F-ERNs during the BART simulation. Smaller F-ERN amplitudes from the BART (but not the BART simulation) were associated with a greater family history density of alcohol problems. The results suggest a possible link between the genetic vulnerability toward developing alcoholism and the brain's response to the negative consequences of behavior.

Delay discounting is a measure of impulsivity describing how a reinforcer loses value as the delay to its receipt increases. Greater delay discounting is reliably observed among those with different substance use disorders (SUDs) compared to the general population. Nevertheless, the relation between delay discounting and the type and number of substances used remains unclear. The aim of this study was to compare delay discounting across four groups of participants: cocaine- and nicotine-dependent participants, cocaine-dependent only participants, nicotine-dependent only participants, and non-dependent controls. One hundred and seven participants completed a computerized delay discounting task for hypothetical monetary values. Data were fit to Mazur's hyperbolic equation to derive the discounting rate k. Results showed that delay discounting was significantly greater in the cocaine- and nicotine-dependent group, compared to the nicotine-dependent only group, compared to control group. Delay discounting was also greater in the cocaine-dependent only group relative to the nicotine-dependent only and control groups, but no differences were observed between the cocaine- and nicotine-dependent group and the cocaine-dependent only group. This study provides evidence that delay discounting differs depending on the type of SUD but not on the number of SUDs.

We studied modulation of the P300 by monetary reward expected to be received on a sustained attention task in 18 individuals with current cocaine use disorders (CUD) and 18 control subjects. Results in the controls revealed sensitivity to money as measured with P300 amplitude and speed of behavioral response and their intercorrelations. In contrast, despite generally faster P300 waveforms and higher self-reported interest in the task, individuals with CUD did not display these responses to money versus nonreward; at the behavioral level, this impairment correlated with frequency of recent cocaine use. These preliminary results suggest a compromised sensitivity to a secondary reinforcer in CUD. This deficit, which needs to be replicated in larger samples of people with currently active versus abstaining CUD, may underlie the compromised ability to advantageously modify behavior in response to changing inner motivations and environmental contingencies.

Drug addiction is characterized by marked disruptions in the ability to process reward. Here we evaluated in cocaine addicted and healthy control participants the subjective sensitivity to reward gradients and its association with neural responses to sustained reward. A self-report questionnaire was used to assess the former. A functional magnetic resonance imaging task that utilized monetary reward as feedback in a blocked design was used to assess the latter. Results revealed that whereas control subjects valued high money more than low money, over half of the cocaine addicted subjects valued all monetary amounts equally. This compromised subjective sensitivity to gradients in reward value was significantly correlated with higher activations to money in the lateral orbitofrontal cortex/inferior frontal gyrus (BA 47) and amygdala, and lower activations in the middle frontal gyrus (BA 6), which together explained 85% of the variability on this rating scale in the cocaine abusers only. These results provide for the first time evidence of restricted subjective sensitivity to gradients of reward in cocaine addiction and of the involvement of frontolimbic brain regions (including the orbitofrontal cortex) in this deficit.

Previous neurobiological and neuropsychological investigations have shown that risk-taking behaviors and addictions share many structural and functional aspects. In particular, both are characterised by an irresistible need to obtain immediate rewards as well as by specific alterations in brain circuits responsible for such behaviors.In this study, we used a transcranial direct-current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) of two samples of subjects (18 dependent cocaine users and 18 control subjects) to investigate the effects of left and right cortical excitability on two risk tasks: the Balloon Analog Risk Task (BART) and the Game of Dice Task (GDT). All subjects randomly received a left anodal/right cathodal stimulation (LAn+), a right anodal/left cathodal stimulation (RAn+), and a sham (placebo) stimulation each run at least 48 hours apart. Participants were asked to perform the BART and the GDT immediately before and after each stimulation.Our results reveal that the activation of the DLPFC (left and right) results in a reduction of risky behaviors at the BART task both in controls subjects and cocaine dependent users. The effect of dTCS on GDT, instead, is more complex. Cocaine users increased safe behavior after right DLPFC anodal stimulation, while risk-taking behavior increased after left DLPFC anodal stimulation. Control subjects performance were only affected by the anodal stimulation of the right DLPFC, resulting in an increase of safe bets. These results support the hypothesis that excessive risk propensity in dependent cocaine users, might be due to a hypoactivation of the right DLPFC, as well as to an unbalance interhemispheres interaction. In conclusion, since risky decision-making seems to be, at least in part, responsible for maintenance and relapse of addiction, we argue that a neuromodulation-based approach could represent a valuable adjunct in the clinical treatment of addiction.

In addition to cognitive and emotional processing dysfunction, chronic cocaine users are also impaired at simple sensorimotor tasks. Many diseases characterized by compulsive movements, repetitive actions, impaired attention and planning are associated with dysfunction in frontal–striatal circuits. The aim of this study was to determine whether cocaine users had impaired frontal–striatal connectivity during a simple movement task and whether this was associated with sensorimotor impairment. Functional MRI data were collected from 14 non-treatment seeking cocaine users and 15 healthy controls as they performed a finger-tapping task. Functional coupling was quantified by correlating the timecourses of each pair of anatomically connected regions of interest. Behavioral performance was correlated with all functional coupling coefficients. In controls there was a significant relationship between the primary motor cortex and the supplementary motor area (SMA), as well as the SMA and the dorsal striatum during ongoing movement. Cocaine users exhibited weaker fronto-striatal coupling than controls, while the cortical–cortical coupling was intact. Coupling strength between the SMA and the caudate was negatively correlated with reaction time in the users. The observation that cocaine users have impaired cortical–striatal connectivity during simple motor performance, suggests that these individuals may have a fundamental deficit in information processing that influences more complex cognitive processes.

Depression is associated with altered sensitivity to reward and punishment, which can influence complex decision-making. We examined punishment sensitivity in the performance of participants with major depressive disorder (MDD) with that of a comparison group on the automatic Balloon Analogue Risk Task (BART), which is a direct measure of risk taking. The present study examined the BART performance of 30 individuals with MDD and 30 matched comparison individuals. The comparison group (M= 63.25) entered a significantly (p< 0.001;d= 1.1) higher number of pumps on the BART than the MDD group (M= 50.83). Higher levels of depression symptoms were significantly correlated (r= -0.40,p< 0.05) with entering a lower number of pumps in the MDD group. MDD patients showed an increased sensitivity to punishment on the BART: after a loss, the MDD group decreased (M= 13.7) the number of subsequent pumps they entered by a significantly (p< 0.001,d= 0.81) greater amount than the comparison group (M= 4.35). This difference applied to losses only: no difference was found between the groups regarding the magnitude of change in pumps selected after a win. Findings suggest the presence of elevated punishment sensitivity among individuals with MDD, which may contribute to the maintenance of depressive symptoms.

Delay discounting and probability discounting tasks providing hypothetical rewards have commonly been used to measure levels of impulsivity and risk taking. Results have been inconsistent as to whether real, compared with hypothetical, rewards influence choice behaviour in delay discounting tasks. This experiment examined choice behaviour in 38 healthy individuals using delay and probability discounting tasks involving both real and hypothetical rewards ( 0.10/ 0.20), real delays, and probabilistic outcomes. It was hypothesized that choice behaviour when receiving real rewards would be less impulsive and less risky than when receiving hypothetical rewards. The tasks were designed so that a mathematical model (the multiplicative hyperbolic model of choice) could be applied to assess effects on discounting parameters. The provision of real rewards was associated with significantly decreased impulsive, but not risky, choice although the size of effect was small and was influenced by the order of presentation. Repeated presentation of both tasks increased quantity discounting but not delay or probability discounting parameters. These results indicate that the nature of the reward provided, and repetition effects, need to be taken into account when designing discounting studies.

In a program of research assessing the validity of the balloon analogue risk task (BART; C. W. Lejuez et al., 2002) as a measure of risk taking, the BART was administered to a sample of inner-city...

It is well documented that monetary reward improves performance of cognitive tasks by increasing task concentration and engagement. In the current study, we investigated the effect of reward expectation on the localized attentional interference effect (LAI). LAI occurs when attending to a visual object degrades the processing of nearby objects, with the interference subsiding with increasing distance from the attended item. The reason for LAI is that, as the separation between the attended items decreases, stimuli presented within receptive fields of the same sets of neurons are processed in a mutually suppressive manner, competing for neural representation. We carried out three experiments combining cuing paradigm and visual search paradigm. A cue indicating the reward condition of each trial (incentive vs. non-incentive) was followed by the presentation of a search array containing two target items (in Experiment 1) or a target item and a salient distractor (in Experiments 2a and 2b). In Experiment 1, participants were asked to discriminate whether the two shape singletons among a set of non-target items were of the same shape or not. The results showed that participants performance declined as the target separation reduced in both the incentive and the non-incentive conditions. The response accuracy in identifying the two targets was higher in the incentive condition than that in the non-incentive condition when the two targets were distant from each other, but the pattern was reversed when they were close to each other. Namely, the LAI effect was larger in the incentive condition than that in the non-incentive condition. In Experiments 2a and 2b, participants were asked to discriminate the orientation of a target while a salient distractor was presented in the search array. In contrast to Experiment 1, results from Experiment 2b revealed LAI effect in the non-incentive condition, but not in the incentive condition. In addition, shorter reaction times and higher response accuracy were observed in the incentive condition than in the non-incentive condition at any target-distractor separations. These results suggested that reward expectation regulates the LAI effect according to the task set, with improved attentional concentration on task-relevant objects and enhanced inhibition to task-irrelevant ones, although this may intensify local competition when two critical objects are both targets.

A within-subject design, using human participants, compared delay discounting functions for real and hypothetical money rewards. Both real and hypothetical rewards were studied across a range that included $10 to $250. For 5 of the 6 participants, no systematic difference in discount rate was observed in response to real and hypothetical choices, suggesting that hypothetical rewards may often serve as a valid proxy for real rewards in delay discounting research. By measuring discounting at an unprecedented range of real rewards, this study has also systematically replicated the robust finding in human delay discounting research that discount rates decrease with increasing magnitude of reward. A hyperbolic decay model described the data better than an exponential model.

No abstract is available for this item.

IMPORTANCE Various neuropsychiatric disorders, especially addictions, feature impairments in risky decision making; clarifying the neural mechanisms underlying this problem can inform treatment. OBJECTIVE To determine how methamphetamine-dependent and control participants differ in brain activation during a risky decision-making task, resting-state functional connectivity within mesolimbic and executive control circuits, and the relationships between these measures. DESIGN, SETTING, AND PARTICIPANTS A case-control, functional magnetic resonance imaging study of methamphetamine-dependent and healthy comparison participants at rest and when performing the Balloon Analogue Risk Task, which involves the choice to pump a balloon or to cash out in the context of uncertain risk. Conducted at a clinical research center at an academic institution, this study involved 25 methamphetamine-dependent and 27 control participants. MAIN OUTCOMES AND MEASURES Parametric modulation of activation in the striatum and right dorsolateral prefrontal cortex (rDLPFC; ie, the degree to which activation changed as a linear function of risk and potential reward), both indexed by pump number, and resting-state functional connectivity, measured in the whole brain with seeds in the midbrain and rDLPFC. Relationships between these outcomes were also tested. RESULTS Parametric modulation of cortical and striatal activation by pump number during risk taking differed with group. It was stronger in the ventral striatum but weaker in the rDLPFC in methamphetamine-dependent participants than control individuals. Methamphetamine-dependent participants also exhibited greater resting-state functional connectivity of the midbrain with the putamen, amygdala, and hippocampus (P < .05, whole brain, cluster corrected). This connectivity was negatively related to modulation of rDLPFC activation by risk level during risky decision making. In control participants, parametric modulation of rDLPFC activation by risk during decision making was positively related to resting-state functional connectivity of the rDLPFC with the striatum. CONCLUSIONS AND RELEVANCE Maladaptive decision making by methamphetamine users may reflect circuit-level dysfunction, underlying deficits in task-based activation. Heightened resting-state connectivity within the mesocorticolimbic system, coupled with reduced prefrontal cortical connectivity, may create a bias toward reward-driven behavior over cognitive control in methamphetamine users. Interventions to improve this balance may enhance treatments for stimulant dependence and other disorders that involve maladaptive decision making.

Aims Problem gambling has been proposed to represent a 'behavioural addiction' that may provide key insights into vulnerability mechanisms underlying addiction in brains that are not affected by the damaging effects of drugs. Our aim was to investigate the neurocognitive profile of problem gambling in comparison with alcohol dependence. We reasoned that shared deficits across the two conditions may reflect underlying vulnerability mechanisms, whereas impairments specific to alcohol dependence may reflect cumulative effects of alcohol consumption. Design Cross-sectional study. Setting Out-patient addiction treatment centres and university behavioural testing facilities. Participants A naturalistic sample of 21 male problem and pathological gamblers, 21 male alcohol-dependent out-patients and 21 healthy male control participants. Measurements Neurocognitive battery assessing decision-making, impulsivity and working memory. Findings The problem gamblers and alcohol-dependent groups displayed impairments in risky decision-making and cognitive impulsivity relative to controls. Working memory deficits and slowed deliberation times were specific to the alcohol-dependent group. Conclusions Gambling and alcohol-dependent groups shared deficits in tasks linked to ventral prefrontal cortical dysfunction. Tasks loading on dorsolateral prefrontal cortex were selectively impaired in the alcohol-dependent group, presumably as a consequence of long-term alcohol use.

In trying to better understand why individuals begin and continue to smoke despite the obvious health consequences, researchers have become interested in identifying relevant personality variables, such as risk taking. In this study, the authors compared the ability of 2 behavioral measures of risk taking, the Bechara Gambling Task (BGT) and the Balloon Analogue Risk Task (BART), to differentiate smokers and nonsmokers. Self-report measures of impulsivity and sensation seeking were taken for comparison with the 2 behavioral risk-taking tasks. Results indicate that behavior on the BART, and not the BGT, was related to smoking status. Further, when considered in a logistic regression analysis, only the Sensation Seeking total score and the BART score contributed uniquely to the differentiation of smokers and nonsmokers.

The present study (N = 86) sought to evaluate a laboratory-based behavioral measure of risk taking (the Balloon Analogue Risk Task; BART) and to test associations between this measure and self-report measures of risk-related constructs as well as self-reported real-world risk behaviors. The BART evidenced sound experimental properties, and riskiness on the BART was correlated with scores on measures of sensation seeking, impulsivity, and deficiencies in behavioral constraint. Also, riskiness on the BART was correlated with the self-reported occurrence of addictive, health, and safety risk behaviors, with the task accounting for variance in these behaviors beyond that accounted for by demographics and self-report measures of risk-related constructs. These results indicate that the BART may be a useful tool in the assessment of risk taking.

Background: Substance dependent individuals (SDIs) consistently show deficits in decision making with biased choices toward immediate rewards, even at the expense of future consequences. However, relatively little evidence has been reported concerning the population of drug abusers who are exclusively addicted to heroin. Methods: The present study tested 124 male abstinent "pure" heroin (AH) abusers (divided into short-term, mid-term, and long-term groups based on their length of abstinence) and 43 healthy controls (HC) intending to address this issue. Two decision-making tasks, the Delay Discounting Task (DDT) and the Iowa Gambling Task (IGT) were employed to measure their decision-making performance. Results: Compared to HC participants, AH participants made significantly poorer choices on both the DDT and the IGT and the poor decision-making performances were not influenced by their lengths of abstinence. It is suggested that heroin-abuse-related decision-making deficits that are demonstrated by rapidly discounting future rewards; preferring incentives with large short-term gains while ignoring accompanying potential risks; and being inflexible in adjusting decision-making behaviors in accordance with outcome feedback, may not be compensated for even after a long period of abstinence from heroin abuse. Conclusion: Hence, this inability to recover should be taken into consideration in the evaluation, prevention and intervention of heroin abuse and relapse. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

Prior studies comparing discounting of delayed hypothetical or potentially real rewards have reported no differences, but they used within-subjects designs. This raises the possibility that participants remembered their choices in one condition and repeated them in the other. In Experiment 1, between-subjects comparisons were made with an adjusting-amount procedure. No significant effect of reward type on delay discounting was detected. Experiment 2 increased the proportion of real rewards and made between- and within-subject comparisons. These comparisons also failed to reveal a significant effect of reward type. Although these findings are consistent with prior findings, caution is urged because choices involving hypothetical rewards have yet to be compared with choices involving real rewards (i.e., the consequences of every choice are obtained) in an experiment using forced-choice trials and steady-state methodology.

A growing literature supports a role for neurocognitive deficits such as impaired decision-making in the development and maintenance of addictive behaviour. On the basis of these findings, it has been suggested that measures of neurocognitive functioning may be applied to the task of predicting clinical outcome in drug addiction. This in turn may have relevance for differentiating treatment based on individual patient needs. To explore this hypothesis we obtained neurocognitive measures of planning, impulsivity and decision-making from 37 opiate dependent individuals within 6 weeks of starting a community drug treatment programme and we followed them up 3 months into the programme. Performance on two tests of decision-making, but not on tests of planning, motor inhibition, reflection impulsivity or delay discounting, was found to predict abstinence from illicit drugs at 3 months with high specificity and moderate sensitivity. In particular, two thirds of the participants performing normally on the Cambridge Gamble Task and the Iowa Gambling Task, but none of those impaired on both, were abstinent from illicit drugs at follow up. Other neuropsychological, psychiatric or psychosocial factors measured in this sample did not explain this finding. The results are discussed in terms of the brain circuitry involved and the potential implications for the planning of treatment services for opiate dependence.

Rationale: Impulsivity is implicated in alcohol dependence, and discounting of delayed rewards may be an objective indicator of impulsiveness. Objectives: This study evaluated delay discounting functions in alcoholics and controls. It compared discounting rates between different magnitudes ($1000 and $100) and different types (money and alcohol) of rewards. Methods: Active alcoholics ( n =19), currently abstinent alcoholics ( n =12) and controls ( n =15) indicated preferences for immediate versus delayed rewards using a titration procedure that determined indifference points at various delays. Four conditions were presented, and the delayed rewards in the four conditions were $1000, $100, 150 bottles of an alcoholic beverage, and 15 bottles of an alcoholic beverage. Results: In all three groups across all four conditions, hyperbolic discounting functions provided a good fit of the data. Linear contrasts, predicting the most rapid discounting rates in active alcoholics, intermediary rates in currently abstinent alcoholics, and the least rapid rates in controls, were significant for three of the four conditions. Alcohol was discounted more rapidly than money. Conclusions: These data provide further evidence of more rapid discounting of delayed rewards in alcohol abusers compared to controls, and especially steep discounting among current users. Rapid discounting of delayed rewards may be a feature related to addictive disorders. A better understanding of how delaying rewards in time impacts their value may have implications for treatment.

Abstract This study evaluated delay discounting functions of substance abusing problem gamblers, substance abusing non-problem gamblers, and non-problem gambling/non-substance abusing controls. Subjects chose between hypothetical monetary amounts available after various delays or immediately. In one condition, a USUS$1000 reward was delayed at intervals ranging from 6 h to 25 years. At each delay interval, the immediately available rewards varied from USUS$1 to USUS$999 until choices reflected indifference between the smaller immediate and larger delayed rewards. In a second condition, the delayed reward was USUS$100, and immediate rewards varied from USUS$0.10 to USUS$99.90. In all three groups, hyperbolic discounting functions provided a good fit of the data, and the smaller reward was discounted at a higher rate than the larger reward. Substance abusers discounted delayed rewards at significantly higher rates than non-substance abusing controls, and problem gambling substance abusers discounted delayed rewards at higher rates than their non-problem gambling substance abusing counterparts. Discounting rates were not associated with types or recency of drug use. These results provide further evidence of more rapid discounting of delayed rewards in substance abusers, and especially among substance abusers with a comorbid gambling problem. Rapid discounting of delayed rewards may be a feature central to impulse control and addictive disorders.

This study examined relations between different patterns of adolescent cigarette smoking and discounting of monetary rewards due to delay (delay discounting) and probabilistic uncertainty (probability discounting). The study also examined the relation between smoking and the number of peer friends who smoke and level of parent education. Participants were 55 adolescents (28 females) between 14 and 16 years of age who were categorized according to the following patterns of smoking behavior: “never smokers” ( n=19; 10 females) who had not tried even one cigarette; “triers” ( n=17; 9 females) who had recently tried cigarettes for the first time; and “current smokers” ( n=19; 9 females) who smoked a minimum of one cigarette every week for at least 6 months prior to data collection. It was hypothesized that current smokers would discount more than those who had never smoked. No specific hypotheses were made for participants only trying cigarettes. Unexpectedly, results indicated no differences in discounting between the current smokers and never smokers. However, the trier group discounted probabilistic rewards significantly more than the never- and current-smoker groups. Also, triers and current smokers both reported having more friends who smoked than never smokers, and fathers of never smokers had significantly more education than fathers of either triers or current smokers. These results suggest that impulsive discounting may be more related to adolescents trying cigarettes than to their becoming regular smokers, whereas number of peer friends who smoke and parent level of education seem to differentiate between those who have smoked to some extent (triers and current smokers) and those who have not even tried cigarettes (never smokers).

We used a novel computerized decision-making task to compare the decision-making behavior of chronic amphetamine abusers, chronic opiate abusers, and patients with focal lesions of orbital prefrontal cortex (PFC) or dorsolateral/medial PFC. We also assessed the effects of reducing central 5-hydroxytryptamine (5-HT) activity using a tryptophan-depleting amino acid drink in normal volunteers. Chronic amphetamine abusers showed sub-optimal decisions (correlated with years of abuse), and deliberated for significantly longer before making their choices. The opiate abusers exhibited only the second of these behavioral changes. Importantly, both sub-optimal choices and increased deliberation times were evident in the patients with damage to orbitofrontal PFC but not other sectors of PFC. Qualitatively, the performance of the subjects with lowered plasma tryptophan was similar to that associated with amphetamine abuse, consistent with recent reports of depleted 5-HT in the orbital regions of PFC of methamphetamine abusers. Overall, these data suggest that chronic amphetamine abusers show similar decision-making deficits to those seen after focal damage to orbitofrontal PFC. These deficits may reflect altered neuromodulation of the orbitofrontal PFC and interconnected limbic-striatal systems by both the ascending 5-HT and mesocortical dopamine (DA) projections.

采用事件相关电位（ERP）技术,探讨同伴在场与自尊水平对青少年冒险行为的影响。实验采用气球模拟风险任务（BART）,比较不同条件下青少年冒险行为量的差异。结果发现：（1）同伴在场时青少年冒险行为更多,比无同伴在场诱发的N1、P3、LPP波幅更大;（2）高自尊青少年更加冒险,且诱发的P3、LPP波幅更大;（3）同伴在场与自尊的交互作用显著,仅高自尊青少年的同伴在场效应明显,诱发出更大波幅的N1、P3、LPP成分。结果提示,同伴在场时高自尊的青少年更可能参与一些非消极的冒险行为,这可能是因为他们对冒险中的奖赏信息更敏感、更兴奋、趋近动机更强。

The Iowa Gambling task, which typically incorporates hypothetical monetary earnings and losses for performance, has been widely used to measure decision-making in substance abusers. We examined the effects of a cash monetary contingency on Gambling task performance in cocaine abusers and control participants. Twenty-two long-term cocaine smokers who met DSM-IV criteria for cocaine dependence and 24 non-cocaine-using control participants completed this study. Both groups were similar in terms of age, executive function, and self-reported alcohol and marijuana use. All participants performed the Gambling task under two counterbalanced conditions: under one condition, earnings and losses were hypothetical, and under the other condition, earnings and losses were in cash. Condition group interactions on card selection and task completion time were noted ( p < 0.05). Under the hypothetical payment condition, cocaine abusers selected a greater proportion of cards from disadvantageous decks than advantageous decks ( p < 0.05), but took a similar amount of time to complete the task, relative to control participants. However, under the cash payment condition, no group differences were seen for card selection and cocaine abusers took more time than controls to complete the task ( p < 0.05). The application of tangible consequences improved the decision-making and effort of cocaine abusers on the Gambling task, relative to control participants. These findings underscore the importance of considering population-specific factors (e.g., sensitivity to instructional vs. consequential control) when conducting neuropsychological research in substance abusers.

Abstract Marijuana (MJ) acutely acts on cannabinoid receptors that are found in numerous brain regions, including those involved in reward processing and decision-making. However, it remains unclear how long-term, chronic MJ use alters reward-based decision-making. In the present study, using [(15)O]water PET imaging, we measured brain activity in chronic MJ users, who underwent monitored abstinence from MJ for approximately 24 h before imaging, and control participants, while they took part in the Iowa Gambling Task (IGT), a monetary decision making task that strongly relies on the ventromedial prefrontal cortex (vmPFC). During PET imaging, participants took part in the standard and a variant version of the IGT as well as a control task. Chronic MJ users performed equally well on the standard IGT, but significantly worse than controls on the variant IGT. Chronic MJ users and control subjects showed increased regional cerebral blood flow (rCBF) in the vmPFC on both versions of the IGT compared to the control task. In the two-group comparison, chronic MJ users showed significantly greater rCBF than controls in the vmPFC on the standard IGT and greater activity in the cerebellum on both versions of the IGT. Furthermore, duration of use, but not age of first use, was associated with greater activity in the vmPFC. Thus, chronic MJ users tend to strongly recruit neural circuitry involved in decision-making and reward processing (vmPFC), and probabilistic learning (cerebellum) when performing the IGT.

In the Iowa Gambling Task, participants have to develop a long-term profitable monetary scenario in a situation of uncertainty and a conflict between the chance of encountering an immediate large reward (US$ 100) in two long-term loosing decks (A and B; US$ 250 per 10 cards) and the chance of encountering an immediate small reward (US$ 50) in two long-term winning decks (C and D; US$ +250 per 10 cards). The ratio of the immediate rewards in decks A/B and C/D is thus 2:1. Here, we manipulated these differences in reward magnitude between the advantageous (C/D) and disadvantageous (A/B) decks, while keeping the net gains and losses per 10 cards the same, to assess the impact of the conflict between immediate and distant pay-off on choice behaviour. Participants selected less cards from disadvantageous decks and won more money when the reward magnitude difference was decreased, A/B:C/D = 1:1, while they selected more cards from disadvantageous decks and lost more money when reward magnitude differences were increased, A/B:C/D = 4:1 and 6:1. This study shows that the outcome in the Iowa Gambling Task is sensitive to differences between the magnitude of immediate rewards in the advantageous and disadvantageous decks.

Decision-making deficits are a robust cognitive correlate of substance abuse, but few studies have addressed the long-term differential associations of cocaine use and marijuana (MJ) use on decision-making. This study utilized the Iowa Gambling Task (IGT), a widely used measure of decision-making, to investigate the relationship between cocaine and MJ use and IGT learning. We analyzed between and within group differences across two consecutive testing sessions in abstinent users of either MJ or cocaine. We assessed long-term correlates of the use of these drugs by evaluating users after 25 days of enforced abstinence. Results showed that both cocaine users and MJ users performed worse than controls on the total IGT net score. All groups showed learning between Session 1 and Session 2, but the cocaine users showed the smallest increase in performance. The pattern of learning from the beginning to the end (block block) of the IGT (Session 2) was different for the drug groups, with the cocaine group showing more learning than the MJ group. Dose-related measures of cocaine use (g/week) and MJ use (joints/week) predicted IGT performance (the heavier the drug use the lower the performance). Differential correlates of cocaine use and MJ use on decision-making learning may have important implications for the development of novel treatment interventions.

在风险情境下人类如何决策是长久以来心理学和经济学研究中一个极具挑战性的核心问题。众多研究采用真实或虚拟金钱作为奖赏强化物来探索风险决策行为的过程和机制,但对金钱奖赏真实性如何影响决策了解很少。仿真气球冒险任务(BART:BalloonAnalogueRiskTask)可以在实验室条件下有效评估个体在真实社会中的风险行为。本研究采用BART任务,通过两个实验探讨和比较了真实与虚拟金钱奖赏对风险决策行为的影响。实验一的结果发现,与虚拟金钱奖赏相比,真实金钱奖赏情境下的风险决策更容易受上一次决策结果的影响,上一次决策失败会导致被试的风险偏好水平显著降低(平均吹气球的次数显著减少),同时决策失败(气球吹爆)次数也显著减少,提示真实金钱奖赏下有更强的反馈学习效应。实验二重复了实验一的结果,并进一步发现,虚拟金钱奖赏的幅度对被试的风险决策行为没有影响,而真实金钱奖赏的幅度能显著改变被试的风险决策行为,较大幅度的真实金钱奖赏可以显著降低被试的风险偏好水平,但这种奖赏幅度对风险偏好的调控效应只对感觉寻求水平低的被试有效,感觉寻求水平高的被试不受影响。这些发现表明真实与虚拟金钱奖赏对风险决策行为有不同的影响。我们的结果可以用风险决策的后悔理论或齐当别模型来解释。

Human decisions are more easily affected by a larger amount of money than a smaller one. Although numerous studies have used hypothetical money as incentives to motivate human behavior, the validity of hypothetical versus real monetary rewards remains controversial. In the present study, we used event-related potential (ERP) with the balloon analogue risk task to investigate how magnitudes of real and hypothetical monetary rewards modulate risk-taking behavior and feedback-related negativity (FRN). Behavioral data showed that participants were more risk averse after negative feedback with increased magnitude of real monetary rewards, while no behavior differences were observed between large and small hypothetical monetary rewards. Similarly, ERP data showed a larger FRN in response to negative feedback during risk taking with large compared to small real monetary rewards, while no FRN differences were observed between large and small hypothetical monetary rewards. Moreover, FRN amplitude differences correlated with risk-taking behavior changes from small to large real monetary rewards, while such correlation was not observed for hypothetical monetary rewards. These findings suggest that the magnitudes of real and hypothetical monetary rewards have differential effects on risk-taking behavior and brain activity. Real and hypothetical money incentives may have different validity for modulating human decisions.

Performance monitoring has been associated with two event-related potentials. The feedback-related negativity reflects a reinforcement-learning signal leading to remedial action, whereas the P3 reflects the motivational significance of feedback outcomes. Till date, research has focused on how these components are influenced by different outcomes within a range of the same, usually monetary,... [Show full abstract]

药物成瘾者和赌博成瘾者常常偏好即刻的奖赏而忽视将来的消极结果。在进行决策任务时,他们倾向于做出不利的选择,偏好短时的获益而不顾长期的损失,这是一种决策障碍的表现。延迟折扣任务（DDT）、爱荷华赌博任务（IGT）和剑桥赌博任务（CGT）是研究决策障碍的三种常用方法和范式,分别考察成瘾人群的冲动性决策、决策短视和决策时的冒险行为。近十几年来的研究表明,前额叶皮层（PFC）在人类的决策活动中起重要作用。其中,腹内侧前额叶（VMPFC）、眶额叶（OFC）、背外侧前额叶（DLPFC）等皮层的功能变化与成瘾人群的决策障碍有密切关系。

Decisional impulsivity represents an important phenotype and a therapeutic target in Internet gaming disorder (IGD). Reality therapy and mindfulness meditation were two approaches to reduce impulsivity. This study aimed to evaluate the efficacy of a group behavioral intervention combining reality therapy and mindfulness meditation in reducing decisional impulsivity and IGD severity. Twenty-five IGD and 21 healthy comparison (HC) young adults participated in baseline tests on the delay discounting and balloon analog risk tasks to measure intertemporal and risky decision-making respectively. Among them, 18 IGD subjects participated in the intervention and were tested again at the end of intervention, and 19 HC subjects without intervention were also tested twice within a similar time period. Results indicate that: (1) at baseline, IGD subjects showed greater intertemporal and risky decisional impulsivity than HC subjects; (2) After intervention, IGD subjects were decreased in delay discounting rate and IGD severity, but did not perform differently on decisional impulsivity in risky choices, as compared with baseline. These findings suggest that decisional impulsivity is a multifaceted behavioral construct and may serve as a possible therapeutic target for IGD. In addition, these results highlight the need for further research into the roles of different forms of decisional impulsivity in the shaping, maintenance, and remission of IGD.

物质滥用和成瘾是当今世界最严重的公共卫生问题之一,禁毒与戒毒已成为全球关注的社会热点.根据DSM-5定义,物质成瘾是一种慢性复发性精神疾病,表现为强迫性药物寻求、无法控制药物使用而无视其潜在的严重危害.超过80%的成瘾个体没有寻求治疗,这部分反映出物质成瘾个体存在认知功能方面的缺陷与障碍.以此为出发点,本研究回顾了近年来关于物质成瘾者在注意、抑制控制、决策和内感受等方面认知功能缺陷的研究,总结了行为和神经影像学方面的成果,探讨和论证物质成瘾背后的认知神经机制,以便更准确地了解物质成瘾的成因、发展、戒断和复发的本质.最后,本研究提出未来的相关研究应致力于推动多技术融合,关注共病问题,构建和完善生物标记,开发基于脑的干预方法,以便深化该领域的研究,有助于完善成瘾病人的干预与治疗机制.

Abnormal decision making is a behavioral characteristic of drug addiction. Indeed, drug addicts prefer immediate rewards at the expense of future interests. Assessing the neurocognitive basis of decision-making related to drug dependence, combining event-related potential (ERP) analysis and source localization techniques, may provide new insights into understanding decision-making deficits in drug addicts and further guide withdrawal treatment. In this study, EEG was performed in 20 abstinent heroin addicts (AHAs) and 20 age-, education- and gender-matched healthy controls (HCs) while they participated in a simple two-choice gambling task (99 vs. 9). Our behavioral results showed that AHAs tend to select higher-risk choices compared with HCs (i.e., more “99” choices than “9”). ERP results showed that right hemisphere preponderance of stimulus-preceding negativity was disrupted in AHAs, but not in HCs. Feedback-related negativity of difference wave was higher in AHAs than HCs, with the P300 amplitude associated with risk magnitude and valence. Using source localization that allows identification of abnormal brain activity in consequential cognitive stages, including the reward expectation and outcome evaluation stages, we found abnormalities in both behavioral and neural responses on gambling in AHAs. Taken together, our findings suggest AHAs have risk-prone tendency and dysfunction in adaptive decision making, since they continue to choose risky options even after accruing considerable negative scores, and fail to shift to a safer strategy to avoid risk. Such abnormal decision-making bias to risk and immediate reward seeking may be accompanied by abnormal reward expectation and evaluation in AHAs, which explains their high risk-seeking and impulsivity.

目的:本研究采用赌博任务考察不同戒断时长的药物戒断者(短期戒断组:平均2.7个月,中期戒断组:平均19.4个月,长期戒断组:平均49.6个月),行为决策能力的损伤与恢复情况。方法:实验中要求药物戒断者与正常控制组完成赌博任务,被试根据屏幕所示的概率判断目标出现在屏幕的左边还是右边。结果:行为结果发现,所有戒断组赌博得分均低于控制组,说明药物戒断者的行为具有高冲动性;中期组和长期组的赌博得分在实验的中期、后期均显著高于实验的前期,表明随着戒断时间延长,药物成瘾对学习能力产生的损伤逐渐恢复。脑电结果发现,面对不同类型的赌博界面,短期组和中期组均未显示出N2波的差异,而长期组能够区分Pass类型与Gamble类型,以及Pass类型与Nogo类型,但是区分的方向与控制组相反,说明药物对长期戒断者决策偏好、选择能力的损伤并未完全恢复。结论:药物成瘾者的行为决策偏好、选择能力和执行控制能力都存在损害,戒断4年后的长期组决策能力有所恢复,但仍未恢复至正常水平。

目的：本研究采用金钱奖赏范式探讨不同戒断时长（短期戒断组：平均2．7个月，中期戒断组：平均19．36个月，长期戒断组：平均49．6个月）的毒品戒断者与正常匹配组，在分辨不同额度的金钱奖赏时认知加工能力的损伤和恢复情况。方法：研究中要求被试在三种不同的奖赏条件（45分，1分，0分）下完成Go／No—go任务。结果：脑电结果表明，对不同额度的金钱奖赏加工时，短期戒断组和中期戒断组的脑区功能受损，表现为其诱发的N2和P3波幅在三种条件下差异都不显著；长期戒断组在奖赏条件下诱发的N2和P3平均波幅显著大于0分条件，但是波幅差异的程度显著低于控制组。结论：长期戒断组和控制组在神经激活模式上存在的差异，表明经过三年以上的戒断后，戒毒人员的脑功能显示出一定水平的恢复，但是仍未恢复至正常水平。