Reliable evidence for implicit attentional responses to aversive conditioned stimuli.

Evidence for implicit aversive learning effects has been criticized for its lack of experimental rigor and statistical reliability. Here we examine whether attentional emotional responses to aversive conditioned stimuli can occur in the absence of stimulus-outcome contingency awareness, and use a novel Bayesian tool to reliably perform a post hoc categorization of awareness. Across two experiments (n = 40 and 69) participants completed an aversive conditioning task. A novel Bayesian awareness categorization tool was applied to sensitively measure contingency awareness. Finally, attentional and subjective responses toward conditioned stimuli were measured. For participants unaware of contingencies, conditioned stimuli generated attentional avoidance, but only aware participants showed subjective learning effects. For both experiments, awareness scores for unaware participants did not regress above chance level on a subsequent awareness check, revealing a reliable determination of unawareness states. These findings provide evidence for the existence of aversive learning in the absence of contingency awareness, as demonstrated via conditioned attentional responses, and build an analytical framework that can be extrapolated to other implicit paradigms. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Can intranasal oxytocin reduce craving in automated addictive behaviours? A systematic review.

Existing pharmacotherapies for managing craving, a strong predictor of relapse to automated addictive behaviours, are limited in efficacy and characterised by increased health risks associated with their pharmacological profile. Preclinical studies have identified oxytocin as a promising pharmacotherapy with anticraving properties for addictive behaviours. Here, we provide the first systematic review of 17 human studies (n = 722; 30% female) investigating the efficacy of intranasal oxytocin to reduce craving or consumption in addictive behaviours. We identify intranasal oxytocin as a method that warrants further investigation regarding its capacity to decrease cue-induced, acute stress-induced or withdrawal-related craving and relapse related to alcohol, cannabis, opioids, cocaine or nicotine, including a potential role as ad hoc medication following exposure to drug-related cues. Future studies should investigate the role of factors such as treatment regimens and sample characteristics, including the role of the amygdala, which we propose as a distinct mechanism mediating oxytocin's anticraving properties.

A feasibility trial of an intervention in alcohol dependence for structured preparation before detoxification versus usual care: the SPADe trial results.

BACKGROUND: Individuals who are 'moderately' or 'severely' dependent consume alcohol at levels that are likely to have a severe impact on their own health and mortality, the health and behaviours of others (family members) and to have economic and social implications. Treatment guidelines suggest that treatment needs to be planned with medically assisted withdrawal (also referred to as detoxification), and aftercare support but outcomes are poor with low proportions engaging in after care and high relapse rates. An approach of structured preparation before alcohol detoxification (SPADe) puts an emphasis on introducing lifestyle changes, development of coping strategies for cravings, stress and emotions as well as introducing changes to the immediate family and social environment in advance of alcohol cessation. Such a pre-habilitation paradigm compliments the established treatment approach. The key research question was: can we design a large scale, randomised controlled trial (RCT) that will answer whether such an approach is more effective than usual care in helping individuals to maintain longer periods of alcohol abstinence? METHODS: This is a pragmatic, parallel, two-arm, feasibility RCT comparing SPADe and usual care against usual care only in maintaining alcohol abstinence in adults with alcohol dependence receiving care in two community addiction services in London. Feasibility outcomes, exploration of primary and secondary clinical outcomes and health economic outcomes are analysed. The trial follows the guidelines of phase 2 of the Medical Research Council (MRC) for complex interventions. RESULTS: We were able to recruit 48/50 participants during a period of 9 months. Retention in the trial for the whole period of the 12 months was 75%. Treatment compliance was overall 44%. Data completion for the primary outcome was 65%, 50% and 63% at 3, 6 and 12 months, respectively. The intervention group had more days abstinent in the previous 90 days at the 12 months (n = 54.5) versus control (n = 41.5). CONCLUSIONS: The results of this feasibility trial indicate that with the appropriate modifications, a full multicentred trial would be possible to test the effectiveness and cost-effectiveness of a pre-habilitation approach such as the SPADe group intervention in addition to usual care against usual care only. TRIAL REGISTRATION: Name of registry: ISRCTN; Trial Registration Number: 14621127 ; Date of Registration: 22/02/2017.

Emotional processes in binge drinking: A systematic review and perspective.

Binge drinking is a widespread alcohol consumption pattern commonly engaged by youth. Here, we present the first systematic review of emotional processes in relation to binge drinking. Capitalizing on a theoretical model describing three emotional processing steps (emotional appraisal/identification, emotional response, emotional regulation) and following PRISMA guidelines, we considered all identified human studies exploring emotional abilities among binge drinkers. A literature search was conducted in PubMed, Scopus, and PsychINFO, and a standardized methodological quality assessment was performed for each study. The main findings offered by the 43 studies included are: 1) regarding emotional appraisal/identification, binge drinking is related to heightened negative emotional states, including greater severity of depressive and anxiety symptoms, and have difficulties in recognizing emotional cues expressed by others; 2) regarding emotional response, binge drinkers exhibit diminished emotional response compared with non-binge drinkers; 3) regarding emotional regulation, no experimental data currently support impaired emotion regulation in binge drinking. Variability in the identification and measurement of binge drinking habits across studies limits conclusions. Nevertheless, current findings establish the relevance of emotional processes in binge drinking and set the stage for new research perspectives to identify the nature and extent of emotional impairments in the onset and maintenance of excessive alcohol use.

Interoceptive cardiac signals selectively enhance fear memories.

Fear is coupled to states of physiological arousal. We tested how learning and memory of threat, specifically conditioned fear, is influenced by interoceptive signals. Forty healthy individuals were exposed to two threat (conditioned stimuli [CS+], paired with electrocutaneous shocks) and two safety (CS-) stimuli, time-locked to either cardiac ventricular systole (when arterial baroreceptors signal cardiovascular arousal to brainstem), or diastole (when these afferent signals are quiescent). Threat learning was indexed objectively using skin conductance responses (SCRs). During acquisition of threat contingencies, cardiac effects dominated: Stimuli (both CS+ and CS-) presented at systole evoked greater SCR responses, relative to stimuli (both CS+ and CS-) presented at diastole. This difference was amplified in more anxious individuals. Learning of conditioned fear was established by the end of the acquisition phase, which was followed by an extinction phase when unpaired CSs were presented at either the same or switched cardiac contingencies. One day later, electrocutaneous shocks triggered the reinstatement of fear responses. Subsequent presentation of stimuli previously encoded at systole evoked higher SCRs. Moreover, only those participants for whom stimuli had the same cardiac-contingency over both acquisition and extinction phases retained conditioned fear memory (i.e., CS+ > CS-). Our findings reveal two important cardiac afferent effects on threat learning and memory: 1) Cardiac signals bias processing toward threat; and 2) cardiac signals are a context for fear memory; altering this context can disrupt the memory. These observations suggest how threat reactivity may be reinforced and maintained by both acute and enduring states of cardiac arousal. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Deter the emotions: Alexithymia, impulsivity and their relationship to binge drinking.

INTRODUCTION: The relevance of both emotion processing and impulsivity to alcohol use and misuse is increasingly recognised, yet there is a scarcity of studies addressing their reciprocal interaction. The present study aimed to examine the role that difficulties in emotion processing and trait impulsivity play in explaining binge drinking pattern of alcohol use in student population. We looked at binge drinking, as it is a risk factor to later alcohol abuse and is a common alcohol drinking habit among students. Alexithymia (from Greek as "deter/repel emotions"), a difficulty in identifying and describing feelings in self and others is increasingly recognised as a feature of alcohol misuse. METHODS: One-hundred and seventy-four student alcohol drinkers were assessed for their drinking habits (Alcohol Use Questionnaire), as well as for alexithymia (Toronto Alexithymia Scale) and impulsivity trait (Barratt Impulsiveness Scale); facial emotional expression judgements were also tested. RESULTS: A direct relationships between, both, alexithymia and impulsivity, and binge drinking was found. When combined, trait impulsivity partially mediated the relationship between alexithymia and binge drinking. Facial emotional expression judgements also showed a relationship with binge drinking. CONCLUSIONS: These findings highlight the importance of both emotion processing and impulsivity in understanding binge drinking and indicate potential routes for prevention and intervention techniques, especially towards those who may be at risk of later alcohol abuse.

123I-Ioflupane dopamine transporter imaging (DaTSCAN) appearances in relation to emotional responsiveness, impulsivity and olfaction in suspected Parkinsonian syndrome.

OBJECTIVE: The aim of our study was to ascertain relationships between DaTSCAN, olfactory loss, behavioural and subjective measurements of impulsivity and emotional responsiveness in patients with clinically suspected Parkinsonian syndrome (PS). METHODS: A prospective study of 20 drug-naive patients with parkinsonism, underwent the University of Pennsylvania Smell Identification Test, impulsivity measurements and mood-state-questionnaires before visual and semi-quantitative DaTQUANT analyses. There were two subgroups: nine patients with scans without evidence of dopaminergic deficit (SWEDD - controls) and 11 patients with PS. RESULTS: The PS group reported lower non-planning impulsivity than the SWEDD group (P = 0.039). A positive correlation was found between the non-planning impulsivity ratings and right anterior putamen/background (bck) ratio in PS group (r = 0.598, P = 0.068). Higher ratings of anger (r = 0.575, P = 0.016), fatigue (r = 0.746, P = 0.001), confusion (r = 0.561, P = 0.019) and depression were positively correlated with putamen/caudate ratios (R > L) on DaTSCAN. Higher self-reported arousal was associated with lower right putamen/caudate ratio (P = -0.581, P = 0.014). Only fatigue was positively correlated with putamen/bck (r = 0.564, P = 0.018). The degree of smell deficit correlated negatively with performance on reflection impulsivity tasks (r = -0.470, P = 0.049). CONCLUSION: DaTSCAN appearances correlated with emotional dysfunction and self-reported impulsivity in patients with PS. Olfactory impairment was associated with increased reflection impulsivity and the age of patients. Higher DaTSCAN putamen/caudate ratios were associated with higher emotional responsiveness and higher non-planning impulsivity in PS patients. These preliminary findings may be relevant in clinical practice in differentiating PS from SWEDD and identifying susceptibility to impulse control disorder although larger studies are warranted.

Differential brain responses for perception of pain during empathic response in binge drinkers compared to non-binge drinkers.

Individuals who engage in binge drinking behaviors may show evidence of impaired cognitive function and emotional dysregulation. Impaired empathy, characterized by a reduced ability to understand and respond appropriately to feelings of others, is increasingly recognized for its role in Alcohol Use Disorders (AUD). The present study examined a population of young adult social drinkers to compare individuals who show binge drinking behavior to those who do not on measures of empathic processing and associated neural responses. A secondary aim explored similarities and differences between binge drinkers living in the UK and France. Alcohol drinking history and impulsivity ratings were recorded from seventy-one participants [(37 UK (Binge drinkers N = 19); 34 France (Binge drinkers N = 17)], who then underwent a neuroimaging study. During functional magnetic resonance imaging, participants viewed images of bodily pain (vs. no-pain), while adopting the perspective of self (pain recipient) or other (observer of someone else experiencing pain). Anterior midcingulate cortex (aMCC) and insula activation distinguished pain from no-pain conditions. Binge drinkers showed stronger regional neural activation than non-binge drinkers within a cluster spanning fusiform gyrus and inferior temporal gyrus, encompassing the Fusiform Body Area. Binge drinkers compared to non-binge drinkers also took longer to respond when viewing pictures depicting pain, in particular when adopting the perspective of self. Relationships between changes in brain activation and behavioural responses in pain versus no pain conditions (self or other perspective) indicated that whereas non-binge drinkers engage areas supporting self to other distinction, binge drinkers do not. Our findings suggest that alcohol binge drinking is associated with different empathy-related behavioral and brain responses, consistent with the proposed importance of empathy in the development of AUD.

Trait Impulsivity Associated With Altered Resting-State Functional Connectivity Within the Somatomotor Network.

Knowledge of brain mechanisms underlying self-regulation can provide valuable insights into how people regulate their thoughts, behaviors, and emotional states, and what happens when such regulation fails. Self-regulation is supported by coordinated interactions of brain systems. Hence, behavioral dysregulation, and its expression as impulsivity, can be usefully characterized using functional connectivity methodologies applied to resting brain networks. The current study tested whether individual differences in trait impulsivity are reflected in the functional architecture within and between resting-state brain networks. Thirty healthy individuals completed a self-report measure of trait impulsivity and underwent resting-state functional magnetic resonance imaging. Using Probabilistic Independent Components Analysis in FSL MELODIC, we identified across participants 10 networks of regions (resting-state networks) with temporally correlated time courses. We then explored how individual expression of these spatial networks covaried with trait impulsivity. Across participants, we observed that greater self-reported impulsivity was associated with decreased connectivity of the right lateral occipital cortex (peak mm 46/-70/16, FWE 1-p = 0.981) with the somatomotor network. No supratheshold differences were observed in between-network connectivity. Our findings implicate the somatomotor network, and its interaction with sensory cortices, in the control of (self-reported) impulsivity. The observed "decoupling" may compromise effective integration of early perceptual information (from visual and somatosensory cortices) with behavioral control programs, potentially resulting in negative consequences.

Does acute stress influence the Pavlovian-to-instrumental transfer effect? Implications for substance use disorders.

RATIONAL: The ability of conditioned stimuli to affect instrumental responding is a robust finding from animal as well as human research and is assumed as a key factor regarding the development and maintenance of addictive behaviour. OBJECTIVES: While it is well known that stress is an important factor for relapse after treatment, little is known about the impact of stress on conditioned substance-associated stimuli and their influence on instrumental responding. METHODS: We administered in the present study a Pavlovian-to-instrumental transfer (PIT) paradigm with stimuli associated with smoking- and chocolate-related rewards using points in a token economy to light to moderate smokers who also indicated to like eating chocolate. After completion of the first two phases of the PIT paradigm (i.e. Pavlovian training and instrumental trainings), participants were randomly allocated to the socially evaluated cold pressor test or a control condition before the final phase of the PIT paradigm, the transfer phase, was administered. RESULTS: The presentation of a smoking-related stimulus enhanced instrumental responding for a smoking-related reward (i.e. 'smoking-PIT' effect) and presentation of a chocolate-related stimulus for a chocolate-related reward (i.e. 'chocolate-PIT' effect) in participants aware of the experimental contingencies as indicated by expectancy ratings. However, acute stress did not change (i.e. neither enhanced nor attenuated) the 'smoking-PIT' effect or the 'chocolate-PIT' effect, and no overall effect of acute stress on tobacco choice was observed in aware participants. CONCLUSIONS: The established role of stress in addiction appears not to be driven by an augmenting effect on the ability of drug stimuli to promote drug-seeking.

The Role of Impulsivity Facets on the Incidence and Development of Alcohol Use Disorders.

Alcohol Use Disorder (AUD) is a chronic relapsing disorder defined according to the Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5; American Psychiatric Association 2013), "by a cluster of behavioural and physical symptoms, which can include, withdrawal, tolerance and craving". Social, emotional, behavioural and cognitive factors are important contributors to AUD. Impulsivity, a multifaceted behavioural concept, defined as a predisposition for rapid and unplanned actions, without considering potential negative consequences of these actions, represents an important such factor. In this chapter, research on the role of distinct impulsivity dimensions in different severity stages of alcohol use is presented.Increased self-reported (trait) impulsivity and an inability to wait, as well as difficulty to adjust behaviour appropriately following a failure to withhold a response are observed across the spectrum of alcohol-use severities. Research on temporal impulsivity (inability to delay gratification) consistently shows deficits in more severe alcohol users. Data on temporal impulsivity in early stages of alcohol use are less consistent, with some studies showing no differences between high and moderate drinkers, while others indicating increased impulsivity in high alcohol users. Data on reflexion impulsivity are currently limited to draw conclusions. Recent research is also presented suggesting the importance of perception and interpretation of physiological and emotional signals on alcohol use behaviour highlighting the necessity of comprehensive integration of the field of the study of emotion and interoception with impulsivity research.

Effect of alcohol on the sense of agency in healthy humans.

Even at low to moderate doses, ingestion of the widely used recreational drug alcohol (ethanol) can impact cognitive and emotional processing. Recent studies show that the sense of agency (SoA; ie, the subjective experience of voluntary control over actions) can be modulated by specific pharmacological manipulations. The SoA, as quantified by the intentional binding (IB) paradigm, is enhanced by direct or indirect dopaminergic agonists in patients with Parkinson's disease and by ketamine (an N-methyl-D-aspartate (NMDA) receptor antagonist) in healthy individuals. These findings implicate dopaminergic and glutamatergic neurotransmission in mechanisms underlying SoA. Alcohol has a complex set of actions, including disinhibition of dopaminergic neurotransmission and allosteric antagonism at NMDA receptors. Here, we tested the hypothesis that low to moderate doses of alcohol would enhance SoA, and impact impulsivity and subjective emotional state. We conducted two experiments in 59 healthy male and female social drinkers, who ingested either a placebo "vehicle," or one of two doses of ethanol: 0.4 and 0.6 g/kg. In both experiments, we observed increased SoA/IB at both doses of alcohol exposure, relative to the placebo condition. We found no correlation between the effects of alcohol on IB and on impulsivity or subjective emotional state. Our findings might have implications for social and legal responsibility related to alcohol use, particularly in states prior to overt intoxication. Further studies are necessary to investigate the effects of alcohol and other addictive substances on the SoA.

The effects of alcohol on sequential decision-making biases during gambling.

RATIONALE: Gambling and alcohol use are recreational behaviours that share substantial commonalities at a phenomenological, clinical and neurobiological level. Past studies have shown that alcohol can have a disinhibiting effect on gambling behaviour, in terms of bet size and persistence. OBJECTIVES: This study was conducted in order to characterise how alcohol affects biases in judgment and decision-making that occur during gambling, with a focus on sequential decision-making including the gambler's fallacy. METHODS: Sequential biases were elicited via a roulette-based gambling task. Using a standard between-groups alcohol challenge procedure, male participants played the roulette task 20 min after receiving an alcoholic (0.8 g/kg; n = 22) or placebo (n = 16) beverage. The task measured colour choice decisions (red/black) and bet size, in response to varying lengths of colour runs and winning/losing feedback streaks. RESULTS: Across both groups, a number of established sequential biases were observed. On colour choice, there was an effect of run length in line with the gambler's fallacy, which further varied by previous feedback (wins vs losses). Bet size increased with feedback streaks, especially for losing streaks. Compared to placebo, the alcohol group placed higher bets following losses compared to wins. CONCLUSIONS: Increased bet size after losses following alcohol consumption may reflect increased loss chasing that may amplify gambling harms. Our results do not fit a simple pattern of enhanced gambling distortions or reward sensitivity, but help contextualise the effects of alcohol on gambling to research on decision-making biases.

Single-response appetitive Pavlovian to instrumental transfer is suppressed by aversive counter-conditioning.

Environmental stimuli, when paired with reward, can influence behaviour in maladaptive ways, for example, by encouraging overeating or addiction. Such behaviour can be sensitive to reward value manipulations, under circumscribed conditions, but whether reward-seeking is also sensitive to stimulus value manipulations remains unclear. Thus, the current experiment investigated whether reducing the hedonic value of a reward-paired stimulus would reduce reward-seeking behaviour. In total, 36 participants successfully completed a single-response Pavlovian-instrumental transfer (PIT) task with a counter-conditioning procedure. The Pavlovian phase associated three conditioned stimuli (CSs) with money at 100%, 50%, or 0% contingency. Counter-conditioning then followed for the experimental group, who saw the 100% CS paired with unpleasant pictures, while the control group saw only neutral images. Instrumental training required participants to learn a button-pressing response to win money. The transfer phase contrasted instrumental responding during baseline and CS presentation. Both experimental and control groups liked the 100% CS more than the other CSs after Pavlovian training, but counter-conditioning reduced this 100% CS liking. In transfer, the experimental group showed an abolition of appetitive PIT, while the control group showed maintenance of appetitive PIT. However, this group difference was only evident in response vigour, not response initiation. In summary, CS hedonic value influences cue-potentiated instrumental responding. More specifically, hedonic value of a reward-paired cue influences the vigour of instrumental responses, but not the decision to initiate a response. These data may have relevance to smoking cessation policies, where the introduction of health warnings may be viewed as a real-world example of counter conditioning.

Prehabilitation in Alcohol Dependence as a Treatment Model for Sustainable Outcomes. A Narrative Review of Literature on the Risks Associated With Detoxification, From Animal Models to Human Translational Research.

In this review paper, we discuss how the overarching concept of prehabilitation is applicable to alcohol dependence. Central to prehabilitation are the concepts of expected harm, risks, and proactive planning to eliminate the harm or cope with the risks. We review the evidence from animal models, psychological experimental studies, as well as pharmacological studies, on the potential risks and harms associated with medically assisted alcohol detoxification and the current treatment paradigm for alcohol dependence. Animal models provide an approximation mostly of the physical aspect of alcohol withdrawal and detoxification process and make predictions about the development of the phenomena in humans. Despite their limitations, these models provide good evidence that withdrawal from chronic ethanol use induces cognitive impairment, which is worsened by repeated bouts of withdrawal and that these impairments are dependent on the duration of alcohol withdrawal. Initial clinical observations with alcohol-dependent patients confirmed increased incidence of seizures. In recent years, accumulating evidence suggests that patients who have had repeated episodes of withdrawal also show changes in their affect, increased craving, as well as significant deterioration of cognitive abilities, when compared to patients with fewer withdrawals. Alcohol dependence is associated with tolerance and withdrawal, with neuroadaptations in γ-Aminobutyric Acid-A Receptor (GABA-A) and glutamatergic N-methyl-D-aspartate (NMDA) receptors playing key roles. It is suggested that dysregulation of the NMDA receptor system underpins alcohol-related memory impairments. Finally, we discuss the Structured Preparation for Alcohol Detoxification (SPADe) as an example of how prehabilitation has been applied in clinical practice. We discuss the importance of partial control over drinking as an interim step toward abstinence and early introduction of lifestyle changes for both the patient and the immediate environment prior to detoxification and while the patient is still drinking.

A feasibility study of an intervention for structured preparation before detoxification in alcohol dependence: the SPADe trial protocol.

BACKGROUND: Alcohol-related harm is currently estimated to cost the National Health Service (NHS) in England £3.5 bn a year. Of the estimated 1.6 million people with some degree of alcohol dependence, some 600,000 are believed to be moderately or severely dependent and may benefit from intensive treatment. Outcomes from medically assisted withdrawal, also referred to as detoxification, are often poor, with poor engagement in relapse prevention interventions and subsequent high relapse rates. Detoxification is costly both financially and to the individual. It has been found that people who experience multiple detoxifications show more emotional and cognitive impairments. These changes may confer upon them the inability to resolve conflict and increased sensitivity to stress thus contributing to increased vulnerability risk of relapse. The study aims to test the feasibility of using a group intervention aiming to prepare participants for long-term abstinence before, rather than after, they have medically assisted detoxification. The current study will establish key parameters that influence trial design such as recruitment, compliance with the intervention, retention, and sensitivity of alternative outcome measures, in preparation for a future randomised controlled trial (RCT). This paper presents the protocol of the feasibility study. METHODS: The study corresponds to phase 2 of the Medical Research Council (MRC) complex interventions guidelines which cover the development and feasibility testing of an intervention. The work is in three stages. The development, adaptation and implementation of the Structured Preparation before Alcohol Detoxification (SPADe) intervention (stage 1), a randomised feasibility study with economic evaluation (stage 2) and a qualitative study (stage 3). Fifty participants will be recruited from two community alcohol treatment services in England. Participants will be randomised in two arms: the treatment as usual arm (TAU), which includes planned medically assisted detoxification and aftercare and the intervention arm in which participants will receive structured group preparation before detoxification in addition to TAU. The main outcomes are duration of continuous abstinence with no incidents of lapse or relapse, percentage of days abstinent and time to relapse. DISCUSSION: The socioeconomic harms associated with alcohol have been well-documented, yet existing treatment options have not been able to reduce high relapse rates. This study will build on existing naturalistic studies underpinned by psychological interventions offered early and before detoxification from alcohol, which aim to reverse automatised habitual behaviours and thus may help us to understand how better to support people to remain abstinent and improve post detoxification outcomes. TRIAL REGISTRATION: ISRCTN, 14621127; Registered on 22 Feb 2017.

Signatures of alcohol use in the structure and neurochemistry of insular cortex: a correlational study.

RATIONALE: Insular cortex supports the representation of motivational feelings through the integration of interoceptive information concerning bodily physiology. Compromised insular integrity is implicated in alcohol and drug use disorders. Alcohol-associated insular dysfunction may arise through aberrant glutamatergic neurotransmission associated with selective neuronal death and atrophy. OBJECTIVE: In a sample of alcohol users, we combined magnetic resonance spectroscopy (MRS) with voxel and surface-based morphometry (VBM, SBM) to test the hypothesis that the neurochemical and structural properties of the insula relate to alcohol use. METHODS: Twenty-three healthy individuals were characterized by measures of alcohol use and subjective craving. Right mid-insula glutamate/glutamine (Glx) and total N-acetylaspartate/N-acetyl-aspartylglutamate (TNAA) concentrations were measured using MRS. Right insular structure was quantified using VBM and SBM parameters. We tested for predictive associations between these neuroimaging and behavioral/psychometric measures using Bayesian statistics. RESULTS: Reduced insular Glx concentration was associated with increased alcohol compulsions and, to a lesser extent, with greater alcohol use severity. Anecdotal evidence for a negative relationship between alcohol use severity and levels of insular gyrification was also observed. CONCLUSIONS: This study is, to date, the first characterization of the neurochemical and morphological integrity of insular cortex in alcohol users. Our data seem to reveal a negative relationship between alcohol use and the neurochemical and structural integrity of the insula, a critical substrate for motivational behavior. These neurobiological characteristics might contribute to loss of control toward compulsive drinking with prolonged and excessive alcohol use.

Interoceptive awareness is associated with acute alcohol-induced changes in subjective effects.

Interoception, the sensing of bodily signals, is related to emotional reactivity and may contribute to the pathophysiology of addiction. Evidence is accumulating that individuals with alcohol use disorders and other substance-dependences show altered interoceptive processing, however little is known about the acute effects of alcohol on interoception and how this may influence the perception of drug induced effects. In a double-blind design, fifty (30 females) healthy young participants were given a beverage containing either a low (0.4 g/kg, n = 18) or high (0.6 g/kg, n = 15) alcohol dose or a placebo (n = 17). After alcohol administration, participants completed two interoceptive paradigms, the heart-beat tracking and heart-beat discrimination tasks, both assessing different accuracy and metacognitive measures of interoception. Subjective feelings elicited by alcohol administration were also measured. Participants under the low alcohol dose had lower metacognitive interoceptive awareness on the discrimination task compared to placebo. Participants under alcohol experienced feelings of light-headedness, which were positively associated with increased interoceptive awareness in the cardiac discrimination task. These results provide evidence for a relationship between interoceptive processing and the perception of drug-induced mood changes. This finding, showing how interoceptive awareness of cardiac discrimination contributes to the appraisal of subjective light-headedness generated by alcohol administration, brings novel perspectives to the understanding of drug discrimination and reinforcement mechanisms.

An experimental study on spontaneous recovery of conditioned reward expectancies and instrumental responding in humans.

The aim of the present study was to investigate spontaneous recovery of reward-expectancies and a reward-associated response in humans and to assess individual factors affecting spontaneous recovery. We therefore implemented an experimental procedure comprising three separate test-sessions. In the first test-session, participants underwent instrumental discrimination training to acquire a conditioned reward-associated response, in the second test-session, memory of this response was tested followed by extinction training. In the third test-session, extinction memory was assessed. Our results demonstrate spontaneous recovery of extinguished conditioned reward-associated expectancies and indicate that differential expectancies after training and extinction and impulsivity significantly predicted the magnitude of spontaneous recovery. In contrast, limited evidence for spontaneous recovery of instrumental responding was found. Given that reward-expectancies might trigger instrumental responding these findings underline the importance of developing extinction procedures that lead to more complete and less fragile long-term extinction of reward-associated responses.