Alcohol-cue exposure decreases response inhibition towards alcohol-related stimuli in detoxified alcohol-dependent patients

Impact of a pre-test measurement of alcohol craving in cue-exposure studies: Relationship with social desirability and demand effects

Craving is one of the most studied concepts in the field of addiction. It is often investigated with repeated-measure experimental designs using self-reported scales. However, the explicit nature of self-reported craving scales may make them vulnerable to social desirability and demand effects. The aim of the present study was to test whether a pre-experimental measurement of craving affects its post-experimental assessment after an alcohol video exposure and whether these changes relate to social desirability, demand effects, and alcohol consumption. Seventy-five healthy volunteers aged 18-30 years were randomly assigned to two experimental groups: a pre-post and a post-only craving assessment group. They were invited to watch an alcohol-related video. Social desirability, demand effects, engagement toward the video, and severity of alcohol consumption were assessed in all participants. The results showed a significant effect of alcohol consumption (p < .001, η2p = .09) on post-experimental craving. The main effect of the repeated measure of craving was also significant (p = .04, η2p = .001), together with the interaction between these two variables (p = .03, η2p = .06). The pre-experimental craving measurement increased its post-experimental levels, but only in heavy drinkers. However, no evidence was found that these changes were related to social desirability or demand effects. Additional exploratory analyses indicated that craving increase in high alcohol drinkers was mediated by a stronger engagement toward the alcohol-related video. In summary, the repeated measurement of craving with explicit scales has a significant impact on the results of alcohol craving studies and may not always be desirable, especially when the true purpose of the study needs to be hidden from the participants. However, the present results also suggest that the pre-post experimental design is advisable when the experimenters seek to maximize the relationship between the individual levels of alcohol consumption and alcohol cue-exposure craving changes.

Using 360-degree immersive videos to assess multiple transdiagnostic symptoms: A study focusing on fear of negative evaluation, paranoid thoughts, negative automatic thoughts, and craving

Over the last 20 years, virtual reality (VR) has gained a great interest for both assessment and treatment of various psychopathologies. However, due to high costs and material specificity, VR remains disadvantageous for clinicians. Adopting a multiple transdiagnostic approach, this study aims at testing the validity of a 360-degree immersive video (360IV) for the assessment of five common psychological symptoms (fear of negative evaluation, paranoid thoughts, negative automatic thoughts, craving for alcohol and for nicotine). A 360IV was constructed in the Darius Café and included actors behaving naturally. One hundred and fifty-eight adults from the general population were assessed in terms of their proneness towards the five symptoms, were then exposed to the 360IV and completed measures for the five state symptoms, four dimensions of presence (place, plausibility, copresence and social presence illusions) and cybersickness. Results revealed that the five symptoms occurred during the immersion and were predicted by the participants' proneness towards these symptoms. The 360IV was also able to elicit various levels of the four dimensions of presence while producing few cybersickness. The present study provides evidence supporting the use of the 360IV as a new accessible, ecological, and standardized tool to assess multiple transdiagnostic symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10055-023-00779-y.

Compulsive Alcohol Seeking and Relapse: Central Role of Conditioning Factors Associated with Alleviation of Withdrawal States by Alcohol

Background and Purpose

Learned associations between environmental stimuli and drugs of abuse represent a major factor in the chronically relapsing nature of drug addiction. In drug dependent subjects these associations must be presumed to include associations linked to reversal of adverse withdrawal states by drug use—“withdrawal‐associated learning” (WDL). However, their significance in drug seeking has received little experimental scrutiny.

Experimental Approach

Using alcohol as a drug of abuse, the behavioural consequences of WDL were investigated in animal models of relapse and compulsive drug seeking by comparing the effects of WD L‐associated stimuli versus stimuli associated with alcohol without WDL experience in nondependent and post‐dependent rats. Brain sites activated by exposure to the respective stimuli were identified by c‐fos immunohistochemistry.

Key Results

(1) WDL‐associated stimuli elicited significant alcohol seeking. In rats with WDL experience, stimuli associated with alcohol in the nondependent state no longer elicited robust alcohol seeking. (2) Responding elicited by WDL‐associated stimuli, but not stimuli conditioned to alcohol in the nondependent state, was resistant to footshock punishment and increased response effort requirements for presentation of WDL‐related stimuli. (3) Stimuli conditioned to alcohol in rats with a dependence but not WDL history did not sustain punished responding or tolerance of increased effort. (4) The central nucleus of the amygdala was identified as a site selectively responsive to WDL stimulus exposure.

Conclusion and Implications

Environmental stimuli associated with reversal of adverse withdrawal states by alcohol elicit compulsive‐like alcohol seeking and establish WDL as a major, not well‐recognized factor, in relapse vulnerability.

How laboratory studies of cigarette craving can inform the experimental alcohol craving literature

Interest in alcohol and other drug craving has flourished over the past two decades, and evidence has accumulated showing that craving can be meaningfully linked to both drug use and relapse. Considerable human experimental alcohol craving research since 2000 has focused on craving as a clinical phenomenon. Self-reported craving to drink typically has served as a catch-all for the craving construct in these studies, whereas few studies have considered craving as a process (or hypothetical construct) that interacts with other phenomena to affect use. In contrast to alcohol, we believe that recently there has been more mechanistic work targeting cigarette craving-related processes. Here, we briefly present a narrative review of studies of acute alcohol craving in humans that have been conducted during the past two decades. We then specify important ways in which alcohol and tobacco differ (e.g., the role of withdrawal), and we note the unique challenges in inducing robust alcohol craving states in the laboratory. Finally, we offer recommendations for how the alcohol field might advance its conceptual understanding of craving by adopting ideas and methods drawn from the smoking research literature. Specifically, we suggest that researchers extend their studies to not only examine the link between alcohol craving and relapse but also to focus on why and, in some instances, how alcohol cravings matter clinically, and the circumstances under which craving especially matters. We propose research to investigate the shifts in alcohol-related cognitive and affective processing that occur during alcohol craving states. Furthermore, we highlight the value of research examining the level of insight that individuals with varying levels of alcohol involvement possess about their own craving-related processing shifts. We believe that laboratory studies can provide rich opportunities to examine conceptual questions about alcohol craving that are central to addiction.

Right Inferior Frontal Activation During Alcohol-Specific Inhibition Increases With Craving and Predicts Drinking Outcome in Alcohol Use Disorder

Alcohol use disorder (AUD) is characterized by enhanced cue-reactivity and the opposing control processes being insufficient. The ability to inhibit reactions to alcohol-related cues, alcohol-specific inhibition, is thus crucial to AUD; and trainings strengthening this ability might increase treatment outcome. The present study investigated whether neurophysiological correlates of alcohol-specific inhibition (I) vary with craving, (II) predict drinking outcome in AUD and (III) are modulated by alcohol-specific inhibition training. A total of 45 recently abstinent patients with AUD and 25 controls participated in this study. All participants underwent functional magnetic resonance imaging (fMRI) during a Go-NoGo task with alcohol-related as well as neutral conditions. Patients with AUD additionally participated in a double-blind RCT, where they were randomized to either an alcohol-specific inhibition training or an active control condition (non-specific inhibition training). After the training, patients participated in a second fMRI measurement where the Go-NoGo task was repeated. Percentage of days abstinent was assessed as drinking outcome 3 months after discharge from residential treatment. Whole brain analyses indicated that in the right inferior frontal gyrus (rIFG), activation related to alcohol-specific inhibition varied with craving and predicted drinking outcome at 3-months follow-up. This neurophysiological correlate of alcohol-specific inhibition was however not modulated by the training version. Our results suggest that enhanced rIFG activation during alcohol-specific (compared to neutral) inhibition (I) is needed to inhibit responses when craving is high and (II) fosters sustained abstinence in patients with AUD. As alcohol-specific rIFG activation was not affected by the training, future research might investigate whether potential training effects on neurophysiology are better detectable with other methodological approaches.

Augmented tendency to act and altered impulse control in alcohol use disorders

Action preparation relies on the operation of control processes that modulate the excitability of the corticospinal tract. On the one hand, excitatory processes prepare the motor system for the forthcoming response; the stronger these influences, the stronger the tendency to act. On the other hand, inhibitory influences allow to suppress inappropriate actions and, more generally, to ensure some sort of impulse control. Because an impairment in these processes could foster inappropriate drinking behavior, the present study aimed at evaluating the motor correlates of such excitatory and inhibitory influences in non-treatment seeking heavy drinkers (HDs) and inpatients suffering from severe alcohol use disorder (SAUDs). Besides, as cue-elicited craving might further alter these processes, we also assessed the impact of an alcohol-related exposure. To do so, 15 healthy controls (HCs), 15 HDs and 15 SAUDs performed a choice reaction time task after having been immersed in a neutral or an alcohol-related environment, using virtual reality videos. Importantly, single-pulse transcranial magnetic stimulation was applied over the left and the right primary motor cortex during the task to elicit motor-evoked potentials in a set of hand muscles allowing us to specifically probe the impact of excitatory and inhibitory processes on motor activity. Our data indicate that excitatory influences are particularly high in both HDs and SAUDs, especially in the dominant hand, an effect that was not observed in HCs. By contrast, inhibitory influences were found to be perfectly normal in HDs, while they were lacking in SAUDs. Furthermore, the alcohol-related exposure enhanced the level of self-reported craving, but this effect only arose in HDs and did not significantly alter the strength of excitatory and inhibitory influences. Overall, although these results have to be taken with caution due to the small sample sizes, this study suggests that enhanced excitatory processes characterize both HDs and SAUDs, while weaker inhibitory influences only concern SAUDs. Hence, an abnormally strong tendency to act could represent a common feature of hazardous drinking, leading individuals to excessive alcohol consumption, whereas deficient impulse control would be a hallmark of more severe forms of AUD, potentially due to the chronic neurotoxic effects of alcohol. Finally, although an alcohol-related exposure does not seem to affect excitatory and inhibitory processes at play during action preparation per se, future works should evaluate changes in corticospinal excitability during the preparation of responses specifically targeting alcohol-related cues.

Olfactory influences on reach-to-press movements in a stop-signal task

Response inhibition is sensitive to unexpected changes in the environment triggered by emotional stimuli. Whereas the impact of visual material on inhibition has been widely documented, the attention on the influence of olfactory stimuli has been neglected. Here, we examined the effect of pleasant (orange), unpleasant (trimethyloxazole), and control (clean air) odour primes in a stop-signal task. Twenty-five participants had to elicit or inhibit reach-to-press actions which allowed to examine the olfactory influences on both the planning (release phase) and the on-line control (reaching phase) of responses. Additionally, we manipulated the distance between the initial hand position and the target to be pressed (10 vs. 20 vs. 30 cm). The pleasant (vs. control) odour impaired inhibition, as reflected in slower stop-signal reaction times and higher release errors, indicating greater mobilisation of inhibitory resources by pleasant stimuli. Further, faster release responses were triggered by pleasant and unpleasant primes, supporting the idea of perceptual prioritisation of emotional (vs. non-emotional) stimuli. The olfactory manipulation did not affect the reaching phase of the responses. Instead, the distance manipulation modulated the reaching but not the release phase. These results extend the sparse literature on the influences of odour stimuli on response inhibition.

Instrumental and Pavlovian Mechanisms in Alcohol Use Disorder

Purpose of Review

Current theories of alcohol use disorders (AUD) highlight the importance of Pavlovian and instrumental learning processes mainly based on preclinical animal studies. Here, we summarize available evidence for alterations of those processes in human participants with AUD with a focus on habitual versus goal-directed instrumental learning, Pavlovian conditioning, and Pavlovian-to-instrumental transfer (PIT) paradigms.

Recent Findings

The balance between habitual and goal-directed control in AUD participants has been studied using outcome devaluation or sequential decision-making procedures, which have found some evidence of reduced goal-directed/model-based control, but little evidence for stronger habitual responding. The employed Pavlovian learning and PIT paradigms have shown considerable differences regarding experimental procedures, e.g., alcohol-related or conventional reinforcers or stimuli.

Summary

While studies of basic learning processes in human participants with AUD support a role of Pavlovian and instrumental learning mechanisms in the development and maintenance of drug addiction, current studies are characterized by large variability regarding methodology, sample characteristics, and results, and translation from animal paradigms to human research remains challenging. Longitudinal approaches with reliable and ecologically valid paradigms of Pavlovian and instrumental processes, including alcohol-related cues and outcomes, are warranted and should be combined with state-of-the-art imaging techniques, computational approaches, and ecological momentary assessment methods.

Drawing alcohol craving process: A systematic review of its association with thought suppression, inhibition and impulsivity

Alcohol Use Disorder (AUD) is a worldwide public health problem. In recent years, there has been growing evidence supporting craving, the irrepressible desire to drink, as a major mechanism implicated in AUD. Impulsivity is identified as playing a significant role in craving in many studies. However, relationships with inhibition and thought suppression remain unclear in the existing literature. A systematic review was conducted to evaluate their associations in order to better understand the cognitive processes involved in craving.

Studies were identified by searching PubMed, PsycINFO and Web of Science using PRISMA procedure and PICOTS framework. There were included if they assessed craving and thought suppression or inhibition or impulsivity, and sample was composed of AUD participants.

Thirteen studies were included and were categorized in accordance with the evaluated cognitive process. The first part dealt with thought suppression and the second with impulsivity and inhibition. Four studies showed a positive association between thought suppression and increased craving. Two studies showed that poorer inhibition was associated with increased craving and four studies showed that impulsivity was positively associated with craving. Three studies showed a negative association between impulsivity and inhibition and higher craving.

Our review highlights the association of alcohol craving with poorer inhibition and greater impulsivity. Further investigations are needed to give support to different theories and lead to propose an integrative model involving the cognitive process of inhibition in alcohol craving.

Alcohol-related context modulates neural correlates of inhibitory control in alcohol dependent patients: Preliminary data from an fMRI study using an alcohol-related Go/NoGo-task

Alcohol use disorder (AUD) is characterized by both impaired inhibitory control and heightened cue reactivity, including enhanced craving and drinking urges in response to alcohol-related stimuli. The interaction between these two mechanisms is thought to be crucial in the maintenance of addiction and relapse. The present study used a newly developed alcohol-related Go/NoGo-task to investigate how exposure to alcohol-related cues affects neural processing of inhibitory control in subjects with AUD. Functional magnetic resonance imaging (fMRI) was recorded during performance of a Go/NoGo task, which incorporated alcohol-related and neutral stimuli as Go and NoGo trials in abstinent AUD patients and healthy controls (HC). AUD patients exhibited increased activation of a fronto-striatal-parietal network during successful response inhibition relative to HC. Within the AUD group, activation for alcohol-related (relative to neutral) inhibition was enhanced in regions including bilateral anterior cingulate cortex (ACC), right medial frontal and precentral gyri, and right putamen. Activation differences in the right ACC increased with subjective craving. These preliminary findings suggest that AUD patients need to recruit enhanced neuronal resources for successful inhibition. In parts of the inhibitory network, this hyperactivation is enhanced when inhibition takes place in an alcohol-related context. Activation in the ACC increased stronger in patients experiencing high craving, possibly because of an enhanced conflict. The task introduced here thus allows to investigate neural processing of alcohol-related inhibition in an AUD sample. The preliminary results suggest that exposure to alcohol-related cues intensifies the demand on an already challenged inhibitory system in recently abstinent patients with AUD.

Behavioral, neurobiological, and neurochemical mechanisms of ethanol self-administration: A translational review

Alcohol use disorder has multiple characteristics including excessive ethanol consumption, impaired control over drinking behaviors, craving and withdrawal symptoms, compulsive seeking behaviors, and is considered a chronic condition. Relapse is common. Determining the neurobiological targets of ethanol and the adaptations induced by chronic ethanol exposure is critical to understanding the clinical manifestation of alcohol use disorders, the mechanisms underlying the various features of the disorder, and for informing medication development. In the present review, we discuss ethanol's interactions with a variety of neurotransmitter systems, summarizing findings from preclinical and translational studies to highlight recent progress in the field. We then describe animal models of ethanol self-administration, emphasizing the value, limitations, and validity of commonly used models. Lastly, we summarize the behavioral changes induced by chronic ethanol self-administration, with an emphasis on cue-elicited behavior, the role of ethanol-related memories, and the emergence of habitual ethanol seeking behavior.

Alcohol Craving in Heavy and Occasional Alcohol Drinkers After Cue Exposure in a Virtual Environment: The Role of the Sense of Presence

The development of new technologies, and more specifically the opportunity to immerse participants in virtual controlled environments, provides a new ecological framework for researchers to study complex behaviors. This experiment aimed to compare post-immersion craving in occasional and heavy alcohol drinkers. Twenty-two occasional drinkers and eighteen heavy drinkers were recruited and immersed in a virtual bar, including alcoholic beverages. After the exposure, heavy drinkers reported a significantly higher craving than occasional drinkers. Post-immersion alcohol craving was significantly related to the levels of perceived ecological validity of the virtual environment. Finally, a moderation analysis suggested that the levels of craving more strongly increased with perceived ecological validity in heavy drinkers than in occasional drinkers. Therefore, the perceived ecological validity was an important experimental parameter to study craving in a virtual environment. These results further suggested that virtual reality might be a useful tool for both the scientific study of alcohol addiction and the treatment of alcohol dependence and relapse.

Task-irrelevant odours affect both response inhibition and response readiness in fast-paced Go/No-Go task: the case of valence

Whether emotional stimuli influence both response readiness and inhibition is highly controversial. Visual emotional stimuli appear to interfere with both under certain conditions (e.g., task relevance). Whether the effect is generalisable to salient yet task-irrelevant stimuli, such as odours, remains elusive. We tested the effect of orthonasally-presented pleasant (orange) and unpleasant odours (trimethyloxazole and hexenol) and clean air as a control on response inhibition. In emotional Go/No-Go paradigms, we manipulated the intertrial interval and ratios of Go/No-Go trials to account for motor (Experiment 1, N = 31) and cognitive (Experiment 2, N = 29) response inhibition processes. In Experiment 1, participants had greater difficulty in withholding and produced more accurate and faster Go responses under the pleasant vs. the control condition. Faster Go responses were also evident in the unpleasant vs. the control condition. In Experiment 2, neither pleasant nor unpleasant odours modulated action withholding, but both elicited more accurate and faster Go responses as compared to the control condition. Pleasant odours significantly impair action withholding (as compared to the control condition), indicating that more inhibitory resources are required to elicit successful inhibition in the presence of positive emotional information. This modulation was revealed for the motor aspect of response inhibition (fast-paced design with lower Go/No-Go trial ratio) rather than for attentional interference processes. Response readiness is critically impacted by the emotional nature of the odour (but not by its valence). Our findings highlight that the valence of task-irrelevant odour stimuli is a factor significantly influencing response inhibition.

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.

Towards a Dynamic Exploration of Vision, Cognition and Emotion in Alcohol-Use Disorders

Abstract: Visuoperceptive impairments are among the most frequently reported deficits in alcohol-use disorders, but only very few studies have investigated their origin and interactions with other categories of dysfunctions. Besides, these deficits have generally been interpreted in a linear bottom-up perspective, which appears very restrictive with respect to the new models of vision developed in healthy populations. Indeed, new theories highlight the predictive nature of the visual system and demonstrate that it interacts with higher-level cognitive functions to generate top-down predictions. These models nota-bly posit that a fast but coarse visual analysis involving magnocellular pathways helps to compute heuristic guesses regard-ing the identity and affective value of inputs, which are used to facilitate conscious visual recognition. Building on these new proposals, the present review stresses the need to reconsider visual deficits in alcohol-use disorders as they might have cru-cial significance for core features of the pathology, such as attentional bias, loss of inhibitory control and emotion decoding impairments. Centrally, we suggest that individuals with severe alcohol-use disorders could present with magnocellular dam-age and we defend a dynamic explanation of the deficits. Rather than being restricted to high-level processes, deficits could start at early visual stages and then extend and potentially intensify during following steps due to reduced cerebral connec-tivity and dysfunctional cognitive/emotional regions. A new research agenda is specifically provided to test these hypotheses.

Decision- and feedback-related brain potentials reveal risk processing mechanisms in patients with alcohol use disorder

Individuals with alcohol use disorder (AUD) are aware of the risks of alcohol abuse yet continue risky drinking. Research indicates that dysfunctional decision processes and trait variables such as impulsivity contribute to this awareness-behavior discrepancy. The present study focused on decision-related versus feedback-related processes as potential contributors to decision making in AUD by examining the relationship between decision choices and decision- and feedback-related ERP phenomena in the balloon analogue risk task (BART). N = 39 AUD and n = 35 healthy comparison participants (HC) performed the BART modified for EEG assessment. In each of 100 runs, participants made a series of choices about whether to pump up a virtual balloon, which popped pseudorandomly, ending the run. Alternatively, participants ended the run by pressing a "cash-out" button. Each pump not producing a pop provided .05 €; popping resulted in loss of the run's accumulated gain. Groups made similar choices, though AUD responded more slowly. The decision P3 200-400 ms after decision prompt (balloon) was larger in AUD than in HC, and decision P3 enhancement on high-risk trials predicted choices to pump. Feedback-related negativity (FRN) after loss (relative to cash out) feedback was smaller in AUD than in HC, suggesting indifference to negative feedback. In AUD, high impulsivity was associated with risk-modulated decision P3 but not FRN. Results indicate atypical decision- and feedback-related processes that could contribute to difficulties in engaging with daily challenges effectively.

Alcohol-related attentional bias in a gaze contingency task: Comparing appetitive and non-appetitive cues

BACKGROUND

Non-problem drinkers attend automatically to alcohol-related cues compared to non-alcohol related cues on tests of inhibitory control. Moreover, attentional bias for alcohol-related cues varies between problem and non-problem drinkers.

AIM

To examine attentional bias towards alcoholic and non-alcoholic appetitive cues between problem and non-problem drinkers.

METHOD

Forty-one university students (9 male, 32 female; Mage = 21.50) completed an eye-tracking gaze contingency paradigm, measuring the number of times participants looked at peripherally and centrally located stimuli (break frequency) when instructed to maintain focus on a target object. Stimuli consisted of appetitive alcohol-related (e.g., wine), appetitive non-alcohol-related (e.g., cola) and non-appetitive (e.g., fabric softener) stimuli. Participants were split using the Alcohol Use Disorders Identification Test (AUDIT) into non-problem (M AUDIT = 3.86) and problematic drinkers (M AUDIT = 11.59).

RESULTS

Problematic drinkers had higher break frequencies towards peripheral appetitive stimuli than towards non-appetitive stimuli, while break frequency was equivalent between appetitive cues presented centrally (alcohol and non-alcohol-related). In contrast, there were no differences in break frequency across stimuli type or cue presentation location (central or peripheral) for non-problem drinkers.

CONCLUSION

In contrast to non-problem drinkers, people displaying more problematic consumption practices may find it more difficult to inhibit eye movements towards appetitive stimuli, particularly when in peripheral vision. This may suggest that attentional biases, as measured in terms of overt eye movements, in problem drinkers may be most powerful when the alcoholic and appetitive stimuli are not directly in field of view. An uncertainty reduction process in the allocation of attention to appetitive cues may help explain the patterns of results observed.

Cue Exposure Therapy for Alcohol Use Disorders: What Can Be Learned from Exposure Therapy for Anxiety Disorders?

Background: Cue Exposure Therapy (CET) has shown efficacy for treating alcohol use disorders (AUDs). Exposure therapy is highly effective for treating anxiety. Both techniques involve repeated, controlled exposures to alcohol or fear-related stimuli. Objectives: We considered the mechanisms of CET for AUDs by comparing it to exposure therapy for anxiety. Method: We conducted a narrative review contrasting theoretical literature examining the mechanisms of CET versus exposure therapy for anxiety. We reviewed RCTs and acute laboratory paradigms examining CET for AUDs. We considered common areas of emerging research, including the use of d-Cycloserine (DCS) and virtual reality (VR). Results: We found evidence that exposure therapy and CET at least partially achieve their effects through extinction learning. We found evidence that CET for AUDs is effective, with comparable benefits to other effective psychosocial treatments. DCS and VR have shown some limited success for augmenting CET for AUDs, so further research is needed to determine their value. Conclusions: There are theoretical and practical similarities between exposure to fear cues and cues of addiction, especially regarding extinction learning. However, these processes are also unique, particularly regarding the differing motivational properties of fear versus reward-related stimuli. We propose that unlike exposure for anxiety, CET takes effect by increasing self-control with each unreinforced exposure. We consider reasons for CET's limited use for AUDs, including its lower acceptability to clients and clinicians. We also note the limited evidence for CET for other substance use disorders, highlighting the need for continued investigation into its mechanisms and efficacy.

Development and Initial Validation of a Rock Climbing Craving Questionnaire (RCCQ)

Conceptual similarities have been identified between experiences of extreme sports athletes and those with drug and behavioral addictions. Evidence suggests rock climbers experience craving and other withdrawal-like states when abstinent from their sport. However, no studies have attempted to quantitatively measure the craving experienced by participants of any extreme sports. Such a measure could allow a greater understanding of the craving experienced by extreme sports athletes and a comparison of these across sports (e.g., surfing) and activities (e.g., drug-use). Therefore, using validated craving measures as a template, the aim of the two studies outlined here was to design and preliminarily validate a subjective multidimensional inventory that could be used to measure craving in the sports of rock-climbing and mountaineering (“RCCQ”). The aim of the first study was to investigate the factor structure of a preliminary measure of craving. Climbers (n = 407) completed the RCCQ. A 3-factor model explained 53.65% of the total variance in item scores. All three factors comprised five items each, which were conceptually labeled as “urge to climb” “negative reinforcement” and “positive reinforcement.” The aim of the second study was to validate the 15-item 3-factor RCCQ resulting from Study 1 using confirmatory factor analysis (CFA). Climbers (n = 254) completed the questionnaire under a climbing-related cue condition or a cue-neutral condition. CFA revealed a good model fit and that all individual parameter estimates were significant and standard errors were within reasonable limits once item 13 was removed from Factor 1. Study 1 supports the multi-dimensional nature of rock climbing craving and shows parallels with substance-related craving in reflecting intention and positive (desire) and negative (withdrawal) reinforcement. Study 2 confirms this factor structure and gives initial validation to the measure with evidence that these factors are sensitive to cue exposure. Given the preliminary nature of the data, any practical implications are tentative. However, if as shown here, craving for climbing (and potentially other extreme sports) is similar to that experienced by drug-users and addicts, there is the potential that climbing and other extreme sports could be used as a replacement therapy for drug users.

The Neurobiological Mechanism of Chemical Aversion (Emetic) Therapy for Alcohol Use Disorder: An fMRI Study

A recent NIH epidemiology study found the lifetime prevalence of alcohol use disorder in the United States to be 29%. Alcohol drinking behavior is strongly "learned" via pleasure center activation/reinforcement. Alcohol craving is a powerful desire to drink alcoholic beverages. Craving was added as one of the defining criteria for alcohol use disorder in DSM5, and craving reduction is becoming an increasingly important treatment goal. In the current study, patients with alcohol use disorder received 10 days of inpatient multi-modal treatments at Schick Shadel Hospital (SSH) of Seattle. The treatments included five chemical aversion conditioning sessions that associated alcohol cues (and alcohol) with nausea and emesis. All patients met DSM4 criteria for alcohol use disorder, were heavy drinkers, and reported craving alcohol pre-treatment. Craving reduction was one of the primary treatment goals. This is the first fMRI study to measure the effects of chemical aversion therapy on alcohol craving-related brain activity. Patients were recruited as subjects for the University of Washington (UW) brain scan study following SSH admission but before treatment onset. Prior to treatment, patients reported craving/desire for alcohol. After treatment (after four SSH chemical aversion treatments, again after five SSH chemical treatments, 30 and 90-days post-discharge), these same patients reported avoidance/aversion to alcohol. Most of the participants (69%) reported being still sober 12 months post-treatment. Consistent with a craving reduction mechanism of how chemical aversion therapy facilitates sobriety, results of the UW fMRI brain scans showed significant pre- to post-treatment reductions in craving-related brain activity in the occipital cortex. Additional fMRI brain scan studies are needed to further explore the neurobiological mechanism of chemical aversion therapy treatment for alcohol use disorder, and other substance use disorders for which chemical aversion therapy is used (e.g., opioid dependence and cocaine dependence). Substance use disorders are estimated to affect well over one billion people worldwide.

Physiological Markers of Motor Inhibition during Human Behavior

Transcranial magnetic stimulation (TMS) studies in humans have shown that many behaviors engage processes that suppress excitability within the corticospinal tract. Inhibition of the motor output pathway has been extensively studied in the context of action stopping, where a planned movement needs to be abruptly aborted. Recent TMS work has also revealed markers of motor inhibition during the preparation of movement. Here, we review the evidence for motor inhibition during action stopping and action preparation, focusing on studies that have used TMS to monitor changes in the excitability of the corticospinal pathway. We discuss how these physiological results have motivated theoretical models of how the brain selects actions, regulates movement initiation and execution, and switches from one state to another.