Heavy social drinkers score higher on implicit wanting and liking for alcohol than alcohol-dependent patients and light social drinkers

Heightened motor impairment as a protective factor against heavy drinking in individuals with high alcohol-induced disinhibition

BACKGROUND

Behavioral disinhibition and motor impairment are both acutely elevated following alcohol consumption, and individual differences in sensitivity to alcohol-induced increases in these effects are associated with drinking habits. Specifically, high alcohol-induced disinhibition and low motor impairment have been identified as separate markers for alcohol-related problems. This study tested the degree to which alcohol-induced disinhibition and motor impairment jointly predict heavy drinking. We hypothesized that heavier drinkers would exhibit a combination of high sensitivity to alcohol-induced disinhibition and low sensitivity to its motor impairing effect.

METHODS

Data from three studies were aggregated to comprise a sample of 96 young adults. Participants' motor coordination (grooved pegboard) and behavioral disinhibition (cued go/no-go) were assessed following consumption of 0.65 g/kg alcohol and a placebo during separate sessions.

RESULTS

As BAC was ascending, alcohol increased motor impairment and disinhibition compared to placebo. Combined effects at this time of alcohol on motor impairment and disinhibition predicted typical drinking habits. Specifically, a combination of high sensitivity to alcohol's disinhibiting effect and low sensitivity to its motor impairing effect was associated with heavy drinking. As BAC was descending, only reduced sensitivity to motor impairment remained as a predictor of heavy drinking.

CONCLUSIONS

The findings suggest that although motor impairment following alcohol consumption is associated with certain negative outcomes (e.g., increased risk for physical injury and motor vehicle accidents), such heightened motor impairment from alcohol may actually serve as a protective factor against the excessive drinking that can accompany the disinhibiting effect of alcohol.

Translating preclinical models of alcohol seeking and consumption into the human laboratory using intravenous alcohol self-administration paradigms

Preclinical models of alcohol use disorder (AUD) have advanced theoretical, mechanistic, and pharmacological study of the human condition. "Liking" and "wanting" behaviors reflect core processes underlying several models of AUD. However, the development and application of translational models of these preclinical approaches are at an incipient stage. The goal of this study was to examine how intravenous free-access and progressive-ratio, operant-response human alcohol self-administration paradigms can be used as translational human model parallels of preclinical "liking" and "wanting." Participants were 40 adults (mean age = 23.7, SD = 2.0; 45% female) of European descent who reported 12.6 drinking days (SD = 5.2) out of the previous 30 (average = 4.1 drinks per drinking day [SD = 1.7]). Individuals diverged in their alcohol self-administration behavior, such that free-access and progressive-ratio paradigm outcomes were not significantly correlated (p = 0.44). Free-access alcohol seeking was related to enjoying alcohol (p < 0.001), but not craving (p = 0.48), whereas progressive-ratio seeking at similar levels of alcohol exposure was related to craving (p = 0.02), but not enjoying (p = 0.30). Family history of alcoholism, venturesomeness traits, and disinhibition traits were unrelated (ps > 0.70) to preferred level of breath alcohol concentration (BrAC) in the free-access session, a measure of liking alcohol. Family history of alcoholism, disinhibition traits, and recent drinking history were significantly related (ps < 0.05) to alcohol seeking in the progressive-ratio paradigm, a measure of wanting alcohol. We conclude that intravenous alcohol self-administration paradigms show promise in modeling behaviors that characterize and parallel alcohol "liking" and "wanting" in preclinical models. These paradigms provide a translational link between preclinical methods and clinical trials.

Evidence for incentive salience sensitization as a pathway to alcohol use disorder

The incentive salience sensitization (ISS) theory of addiction holds that addictive behavior stems from the ability of drugs to progressively sensitize the brain circuitry that mediates attribution of incentive salience (IS) to reward-predictive cues and its behavioral manifestations. In this article, we establish the plausibility of ISS as an etiological pathway to alcohol use disorder (AUD). We provide a comprehensive and critical review of evidence for: (1) the ability of alcohol to sensitize the brain circuitry of IS attribution and expression; and (2) attribution of IS to alcohol-predictive cues and its sensitization in humans and non-human animals. We point out gaps in the literature and how these might be addressed. We also highlight how individuals with different alcohol subjective response phenotypes may differ in susceptibility to ISS as a pathway to AUD. Finally, we discuss important implications of this neuropsychological mechanism in AUD for psychological and pharmacological interventions attempting to attenuate alcohol craving and cue reactivity.

Predicting Behavior With Implicit Measures: Disillusioning Findings, Reasonable Explanations, and Sophisticated Solutions

Two decades ago, the introduction of the Implicit Association Test (IAT) sparked enthusiastic reactions. With implicit measures like the IAT, researchers hoped to finally be able to bridge the gap between self-reported attitudes on one hand and behavior on the other. Twenty years of research and several meta-analyses later, however, we have to conclude that neither the IAT nor its derivatives have fulfilled these expectations. Their predictive value for behavioral criteria is weak and their incremental validity over and above self-report measures is negligible. In our review, we present an overview of explanations for these unsatisfactory findings and delineate promising ways forward. Over the years, several reasons for the IAT's weak predictive validity have been proposed. They point to four potentially problematic features: First, the IAT is by no means a pure measure of individual differences in associations but suffers from extraneous influences like recoding. Hence, the predictive validity of IAT-scores should not be confused with the predictive validity of associations. Second, with the IAT, we usually aim to measure evaluation ("liking") instead of motivation ("wanting"). Yet, behavior might be determined much more often by the latter than the former. Third, the IAT focuses on measuring associations instead of propositional beliefs and thus taps into a construct that might be too unspecific to account for behavior. Finally, studies on predictive validity are often characterized by a mismatch between predictor and criterion (e.g., while behavior is highly context-specific, the IAT usually takes into account neither the situation nor the domain). Recent research, however, also revealed advances addressing each of these problems, namely (1) procedural and analytical advances to control for recoding in the IAT, (2) measurement procedures to assess implicit wanting, (3) measurement procedures to assess implicit beliefs, and (4) approaches to increase the fit between implicit measures and behavioral criteria (e.g., by incorporating contextual information). Implicit measures like the IAT hold an enormous potential. In order to allow them to fulfill this potential, however, we have to refine our understanding of these measures, and we should incorporate recent conceptual and methodological advancements. This review provides specific recommendations on how to do so.

Examining neural reactivity to gambling cues in the age of online betting

Purpose of Review

The goal of this review is to provide new insights as to how and why functional magnetic resonance imaging (fMRI) research on gambling cue reactivity can contribute to significant progress towards the understanding of gambling disorder. After having offered a detailed description of experimental paradigms and a comprehensive summary of findings related to gambling cue reactivity, the present review suggests methodological avenues for future research.

Recent Findings

The fMRI literature on problem gambling has identified the main neural pathways associated with reactivity to gambling cues. Yet, the current knowledge on the key factors underlying cue reactivity in gambling is still very incomplete. Here, we suggest that the recent expansion of online sports betting calls for a new line of research offering a fine-grained and up-to-date approach of neural cue reactivity in gambling disorder.

Summary

Experimental designs that investigate individual-specific and study-specific factors related to sports betting have the potential to foster progress towards efficient treatment and prevention of gambling disorder.

The implicit beliefs and implicit behavioral tendencies towards smoking-related cues among Chinese male smokers and non-smokers

BACKGROUND

The dual-process theory is central to several models of addiction, implying the importance of automatic processes in the maintenance and development of addiction. Implicit beliefs are traces of previous experience which relate to the representation in cognition. Implicit behavioral tendencies are traces of previous experience which relate to the representation in behavioral tendencies. In this study, we aim to provide behavioral evidence for implicit beliefs and implicit behavioral tendencies towards smoking-related cues among Chinese male smokers and non-smokers. We also examine the relationships among implicit beliefs, implicit behavioral tendencies and smoking behaviors of smokers.

METHODS

In order to achieve these goals, we used an implicit association test (IAT) to measure implicit beliefs and implicit behavioral tendencies simultaneously. Thirty-nine smokers and twenty-five non-smokers were tested, using smoking-related words and images, as well as neutral words and images as stimuli.

RESULTS

Our analysis shows significant differences in smokers' and non-smokers' implicit beliefs and behavioral tendencies (t₆₂ = 3.494, p < 0.001; t₆₂ = 5.034, p < 0.001). In the group of smokers, implicit beliefs and implicit behavioral tendencies were positively correlated with each other (r = 0.460, p < 0.01). In addition, smokers' scores for implicit behavioral tendencies are negatively correlated with the number of cigarettes smoked per day (r = - 0.51, p < 0.001).

CONCLUSIONS

This study suggests that implicit beliefs and behavioral tendencies toward smoking-related cues vary significantly between Chinese male smokers and non-smokers. In addition, there is a positive correlation between implicit beliefs and behavioral tendencies within smokers. It also shows for the first time that the implicit behavioral tendencies are related to smoking behaviors. Our results may be considered as references for smoking cessation interventions focused on changes at the implicit level, and they provide a new perspective for measuring different dimensions of implicit attitudes by an IAT. This finding might promote the development of the network theory of implicit attitudes.

Competing Motivations: Proactive Response Inhibition Toward Addiction-Related Stimuli in Quitting-Motivated Individuals

We examined whether addiction-related cues impact proactive inhibition (the restraint of actions in preparation for stopping) in individuals who are motivated to quit gambling or cannabis use. In Study 1, treatment-seeking individuals with cannabis use disorder and matched controls performed a stop-signal task that required them to inhibit categorizing cannabis or neutral pictures, and within varying levels of stop-signal probability. In Study 2, two groups of individuals, who applied to a voluntary self-exclusion program toward gambling, performed the stop-task following relaxation or gambling craving induction, with results compared to non-gamblers. Study 1 showed that despite being less efficient in proactive inhibition, individuals with cannabis use disorder exhibited heightened proactive inhibition toward cannabis cues. In Study 2, proactive inhibition toward gambling cues was heightened in gamblers after craving, but the degree of proactive adjustment decreased as a function of induced changes in gambling-related motivation. Present findings demonstrate that exposure to addiction-related cues can modulate proactive inhibition in individuals who are motivated to restrict their addictive behaviors.

Dissociation between wanting and liking for alcohol and caffeine: A test of the Incentive Sensitisation Theory

Limited human studies have directly tested the dissociation between wanting and liking with human substance users, a core tenet of the Incentive Sensitisation Theory (IST). The aim of this study is to test the dissociation between wanting and liking in humans across two commonly used licit substances, alcohol and caffeine. The STRAP-R (Sensitivity To Reinforcement of Addictive and other Primary Rewards) questionnaire was administered to 285 alcohol users (mean age=33.30, SD= 8.83) and 134 coffee users (mean age=33.05, SD=8.10) ranging in their levels of substance use to assess wanting and liking. Findings showed that in high risk alcohol users wanting may drive alcohol consumption more so than liking, compared with low risk alcohol users. However, wanting and liking did not significantly dissociate as alcohol consumption increased. These findings partially support IST. Additionally, IST was not supported in coffee users. It is possible that caffeine functions differently at the neurological level compared with alcohol, perhaps explaining the lack of dissociation emerging in coffee users as caffeine use increased. Nevertheless, the current study makes several contributions to IST research. Future studies should focus on utilising the STRAP-R with a clinically dependent sample to test the dissociation between wanting and liking.

Beyond associations: Do implicit beliefs play a role in smoking addiction?

BACKGROUND AND OBJECTIVES

Influential dual-system models of addiction suggest that an automatic system that is associative and habitual promotes drug use, whereas a controlled system that is propositional and rational inhibits drug use. It is assumed that effects on the Implicit Association Test (IAT) reflect the automatic processes that guide drug seeking. However, results have been inconsistent, challenging: (1) the validity of addiction IATs; and (2) the assumption that the automatic system contains only simple associative information. We aimed to further test the validity of IATs that are used within this field of research using an experimental design. Second, we introduced a new procedure aimed at examining the automatic activation of complex propositional knowledge, the Relational Responding Task (RRT) and examine the validity of RRT effects in the context of smoking.

METHODS

In two experiments, smokers performed two different tasks: an approach/avoid IAT and a liking IAT in Experiment 1, and a smoking urges RRT and a valence IAT in Experiment 2. Smokers were tested once immediately after smoking and once after 10 hours of nicotine-deprivation.

RESULTS

None of the IAT scores were affected by the deprivation manipulation. RRT scores revealed a stronger implicit desire for smoking in the deprivation condition compared to the satiation condition.

CONCLUSIONS

IATs that are currently used to assess automatic processes in addiction have serious drawbacks. Furthermore, the automatic system may contain not only associations but complex drug-related beliefs as well. The RRT may be a useful and valid tool to examine these beliefs.

Behavioral sensitization to ethanol: Neural basis and factors that influence its acquisition and expression

Ethanol-induced behavioral sensitization (EBS) was first described in 1980, approximately 10 years after the phenomenon was described for psychostimulants. Ethanol acts on γ-aminobutyric acid (GABA) and glutamate receptors as an allosteric agonist and antagonist, respectively, but it also affects many other molecular targets. The multiplicity of factors involved in the behavioral and neurochemical effects of ethanol and the ensuing complexity may explain much of the apparent disparate results, found across different labs, regarding ethanol-induced behavioral sensitization. Although the mesocorticolimbic dopamine system plays an important role in EBS, we provide evidence of the involvement of other neurotransmitter systems, mainly the glutamatergic, GABAergic, and opioidergic systems. This review also analyses the neural underpinnings (e.g., induction of cellular transcription factors such as cyclic adenosine monophosphate response element binding protein and growth factors, such as the brain-derived neurotrophic factor) and other factors that influence the phenomenon, including age, sex, dose, and protocols of drug administration. One of the reasons that make EBS an attractive phenomenon is the assumption, firmly based on empirical evidence, that EBS and addiction-related processes have common molecular and neural basis. Therefore, EBS has been used as a model of addiction processes. We discuss the association between different measures of ethanol-induced reward and EBS. Parallels between the pharmacological basis of EBS and acute motor effects of ethanol are also discussed.

Implicit measures of "wanting" and "liking" in humans

Incentive Sensitization Theory (IST; e.g., Robinson and Berridge, 1993. Brain Res. Rev., 18, 291; Robinson and Berridge, 2003 Trends Neurosci., 26, 507) suggests that a common dopamine system that deals with incentive salience attribution is affected by different types of drugs. Repeated drug use will sensitize this neural system, which means that drugs increasingly trigger the experience of incentive salience or "wanting". Importantly, Robinson and Berridge stress that there is a dissociation between drug "wanting" (the unconscious attribution of incentive salience) and drug "liking" (the unconscious hedonic experience when one consumes drugs). Whereas the former plays an essential role in the development and maintenance of drug addiction, the latter does not. Although this model was based mainly on research with non-human animals, more recently the dissociation between "wanting" and "liking" has been examined in humans as well. A widely used and promising means of studying these processes are behavioral implicit measures such as the Implicit Association Test (IAT), the Approach-Avoidance Task (AAT), different types of Stimulus-Response Compatibility (SRC) tasks, and Affective Simon Tasks (AST). IST makes the clear prediction that (1) there should be a positive correlation between indices of "wanting" (e.g., drug consumption) and implicit "wanting" scores. Similarly, there should be a positive correlation between indices of "liking" (e.g., various expressions of subjective pleasure) and implicit "liking" scores; (2) there should be higher "wanting" scores in substance abusers or frequent substance users compared to non-users or infrequent users, and there should be no differences in "liking" between these groups (or even less "liking" in frequent substance users); (3) manipulations of "wanting" should affect implicit "wanting" scores whereas manipulations of "liking" should affect implicit "liking" scores. However, studies that tested these hypotheses did not produce equivocal results. To shed light on these discrepancies, we first discuss the different definitions of "wanting" and "liking" and the different tests that have been used to assess these processes. Then, we discuss whether it is reasonable to assume that these tests are valid measures of "wanting" and "liking" and we review correlational, quasi-experimental, and experimental studies that inform us about this issue. Finally, we discuss the future potential of implicit measures in research on IST and make several recommendations to improve both theory and methodology.