The acute effects of cannabis, with and without cannabidiol, on attentional bias to cannabis related cues: a randomised, double-blind, placebo-controlled, cross-over study.

RATIONALE: Attentional bias to drug-related stimuli is hypothesised to contribute towards addiction. However, the acute effects of Δ9-tetrahydrocannabinol (THC) on attentional bias to cannabis cues, the differential response in adults and adolescents, and the moderating effect of cannabidiol (CBD) are unknown. OBJECTIVES: Our study investigated (1) the acute effects of vaporised cannabis on attentional bias to cannabis-related images in adults and adolescents and (2) the moderating influences of age and CBD. METHODS: We conducted a randomised, double-blind, placebo-controlled, cross-over study where three weight-adjusted vaporised cannabis preparations: 'THC' (8 mg THC for a 75-kg person), 'THC + CBD' (8 mg THC and 24 mg CBD for a 75-kg person) and PLA (matched placebo). Cannabis was administered on 3 separate days to 48 participants, who used cannabis 0.5-3 days/week: 24 adolescents (12 females, aged 16-17) and 24 adults (12 females, aged 26-29). Participants completed a visual probe task with cannabis cues. Our primary outcome was attentional bias to cannabis stimuli, measured using the differential reaction time to a cannabis vs. neutral probe, on 200-ms trials. RESULTS: In contrast to hypotheses, attention was directed away from cannabis cues on placebo, and there was a main effect of the drug (F(2,92) = 3.865, p = 0.024, η2p = 0.077), indicating THC administration eliminated this bias. There was no significant impact of CBD nor an age-by-drug interaction. CONCLUSIONS: Acute THC intoxication eliminated attentional bias away from cannabis cues. There was no evidence of differential response in adolescents compared to adults and no evidence that a moderate vaporised dose of CBD altered the impact of cannabis on attentional bias. TRIAL REGISTRATION: This study was listed with the US National Library of Medicine and registered on ClinicalTrials.gov, URL: Do Adolescents and Adults Differ in Their Acute Response to Cannabis?-Full Text View-ClinicalTrials.gov, registration number: NCT04851392.

Intoxication without anticipation: Disentangling pharmacological from expected effects of alcohol.

BACKGROUND: The pharmacological effects of alcohol on executive function, craving and subsequent alcohol-seeking have been well documented. Yet, insufficient methodological controls within existing alcohol administration paradigms have meant that the relative importance of alcohol's pharmacological and anticipatory effects remains in need of further elucidation. AIM: The objective of this study is to disentangle alcohol's pharmacological effects from its anticipatory effects on alcohol-related cognitions and subsequent consumption. METHODS: Inhibitory control, attentional bias and craving were assessed pre- and post-consumption in 100 participants who were randomly allocated to one of four beverage conditions in a two by two design: (1) alcohol aware (alcohol with participant knowledge (pharmacological/anticipation effects)), (2) alcohol blind (alcohol without participant knowledge; in a novel grain alcohol masking condition (pharmacological/no anticipation effects)), (3) placebo (no alcohol but participants were deceived (anticipation/non-pharmacological effects)) and (4) pure control (no alcohol with participant knowledge (no anticipation/non-pharmacological effects)). RESULTS: Findings suggest that the pharmacological effects of alcohol result in greater inhibitory control impairments compared with anticipated effects. Anticipatory but not the pharmacological effects of alcohol were found to increase attentional bias. Both pharmacology and anticipation resulted in increased craving, though higher levels of craving were observed due to alcohol's pharmacology. Furthermore, alcohol pharmacology resulted in heightened ad libitum consumption; however, anticipation did not. Changes in craving partially mediated the relationship between initial intoxication and subsequent drinking, while inhibitory control impairments did not. CONCLUSIONS: Successive alcohol consumption appears driven primarily by the pharmacological effects of alcohol which are exerted via changes in craving.

Effects of hydrocortisone and yohimbine on selective attention to emotional cues.

INTRODUCTION: Facial expressions contain important affective information, and selective attention to facial expression provides an advantage in the face of loss, stress and danger. In addition, the sympathetic nervous system and hypothalamus-pituitary-adrenal axis mediate the organism's response to loss and danger. Here, we aimed at investigating the influence of sympathetic nervous system and hypothalamus-pituitary-adrenal axis activation on selective attention to affective facial stimuli. METHODS AND MATERIALS: One hundred-and-four healthy men between 18-35 years old (mean (standard deviation) age: 24.1 (3.5) years) participated in the study. We used a randomised, double-blind, placebo-controlled design. Participants received either: (a) yohimbine, (b) hydrocortisone, (c) yohimbine and hydrocortisone or (d) placebo only and participated in a dot-probe task with sad, happy and neutral faces. We collected salivary samples to measure cortisol and alpha amylase activity in addition to measurements of blood pressure and heart rate. Salivary cortisol served as correlate of hypothalamus-pituitary-adrenal axis activation and salivary alpha amylase activity, blood pressure and heart rate as correlates of sympathetic nervous system activation. Measurements were carried out before and after drug administration. RESULTS: We did not find a main effect or interaction effect of hydrocortisone or yohimbine administration on selective attention to happy faces. However, we found an interaction of yohimbine and hydrocortisone on selective attention to sad faces. Post-hoc t-test revealed an attentional bias away from sad stimuli and towards neutral faces in the hydrocortisone-only group. DISCUSSION: Only hydrocortisone administration led to an attentional bias away from sad faces. Future studies should investigate these effects in major depression disorder, as this disorder is characterised by glucocorticoid resistance and increased processing of sad stimuli.

Methylphenidate reduces orienting bias in healthy individuals.

BACKGROUND: Healthy individuals show subtle orienting bias, a phenomenon known as pseudoneglect, reflected in a tendency to direct greater attention toward one hemispace. Accumulating evidence indicates that this bias is an individual trait, and attention is preferentially directed contralaterally to the hemisphere with higher dopamine signaling. Administration of methylphenidate (MPH), a dopamine transporter inhibitor, was shown to normalize aberrant spatial attention bias in psychiatric and neurological patients, suggesting that the reduced orienting bias following administration of MPH reflects an asymmetric effect of the drug, increasing extracellular dopamine in the hemisphere with lower dopamine signaling. AIM: We predicted that, similarly to its effect on patients with brain pathology, MPH will reduce the orienting bias in healthy subjects. METHODS: To test this hypothesis, we examined the behavioral effects of a single dose (20 mg) of MPH on orienting bias in 36 healthy subjects (18 females) in a randomized, double-blind placebo-controlled, within-subject design, using the greyscales task, which has been shown to detect subtle attentional biases in both patients and healthy individuals. RESULTS/OUTCOMES: Results demonstrate that healthy individuals vary in both direction and magnitude of spatial orienting bias and show reduced magnitude of orienting bias following MPH administration, regardless of the initial direction of asymmetry. CONCLUSIONS/INTERPRETATIONS: Our findings reveal, for the first time in healthy subjects, that MPH decreases spatial orienting bias in an asymmetric manner. Given the well-documented association between orienting bias and asymmetric dopamine signaling, these findings also suggest that MPH might exert a possible asymmetric neural effect in the healthy brain.

An interoceptive basis for alcohol priming effects.

RATIONALE: Alcohol priming can modulate the value of rewards, as observed through the effects of acute alcohol administration on cue reactivity. However, little is known about the psychophysiological mechanisms driving these effects. Here, we examine how alcohol-induced changes in bodily states shape the development of implicit attentional biases and explicit cue reactivity. OBJECTIVES: To characterize the interoceptive correlates of alcohol priming effects on alcohol attentional biases and cue reactivity. METHODS: In a two-session double-blind alcohol administration procedure, participants (n=31) were given a 0.4-g/kg dose of alcohol or a placebo drink. Cardiovascular responses were measured before and after alcohol administration to observe the effects of alcohol on viscero-afferent reactivity, as indexed through changes in heart rate variability (HRV) at or near 0.1 Hz (0.1-Hz HRV). Next, participants completed a modified flanker task to examine implicit alcohol attentional biases and provided subjective valence and arousal ratings of alcohol cues to examine explicit cue reactivity. RESULTS: We found that changes in 0.1-Hz HRV after alcohol administration positively correlated with attentional biases, and negatively correlated with alcohol valence ratings; blood alcohol content was a null predictor. CONCLUSIONS: This is novel evidence that suggests alcohol-induced changes in bodily states may mediate the occurrence of alcohol priming effects and highlights the potentially generative role of interoceptive mechanisms in alcohol-related behaviors. The differential patterns revealed by implicit biases and explicit response tendencies are considered within the context of the dissociation between wanting and liking.

Alcohol attention bias in 14-16 year old adolescents: an eye tracking study.

RATIONALE: Theoretical models regarding the automaticity of attentional processes highlight a progression of attentional bias style from controlled to automatic in drinking populations as alcohol use progresses. Previous research has focused on older adolescent and adult drinking populations at later stages in their drinking career. OBJECTIVES: The aim of this study was to investigate alcohol attention bias in 14-16-year-old adolescent social drinkers and abstainers. METHODS: Alcohol attention bias was measured in social drinking and abstaining groups in an eye-tracking paradigm. Questionnaires measured alcohol use, expectancies, exposure and socially desirable response styles. RESULTS: Social drinkers fixated to alcohol stimuli more frequently and spent a larger proportion of their fixation time attending to alcohol stimuli compared to non-drinkers. Groups displayed differences in their style of attentional processing of alcohol-related information, with heavy drinkers fixating significantly longer to alcohol information across alcohol stimulus presentation and exhibiting a delayed disengagement style of alcohol attention bias that differentiated them from light drinking and abstaining peers. All social drinkers fixated significantly more than abstainers in the latter half of alcohol stimulus presentation. CONCLUSION: Alcohol attention bias was present in this adolescent sample. Drinking subgroups are defined from abstaining peers by unique features of their attentional bias that are controlled in nature. These findings are comparable to those in other adolescent and adult social drinking populations. The identification of specific attentional bias features according to drinking subpopulations has implications for our theoretical understanding of developing alcohol attention bias and problematic drinking behaviours, as well as at-risk identification and early intervention.

Potential shortcomings in current studies on the effect of intranasal oxytocin in Anorexia Nervosa and healthy controls - A systematic review and meta-analysis.

RATIONALE: The psychopathology of anorexia nervosa (AN) includes altered social cognition and information processing of fear and anxiety. Oxytocin, a neuromodulating hormone, may influence these functions and could be valuable for the treatment of AN. OBJECTIVE: The current study aimed at reviewing the effect of intranasal oxytocin (IN-OT) on attentional bias (AB) and emotion recognition (ER) in AN. METHODS: A systematic literature review was done for free-text and the MeSH-terms: anorexia nervosa, feeding and eating disorders, and oxytocin. Six publications, reporting from 4 unique clinical trials, were included in this review. A meta-analysis was conducted to examine the effects of IN-OT on AB towards food images and ER on healthy controls (HC) and patients with AN. RESULTS: Overall, IN-OT did not influence AB towards food images (effect size = 0.20 [- 0.16, 0.57], p = 0.28) and had no effect on ER (effect size = - 0.01 [- 0.27, 0.26], p = 0.97) in patients with AN and healthy control (HC) subjects collectively. Assessing HC and AN separately in subgroup analyses did not show any significant effect on AB and ER in neither of the subgroups. All tests were done between 15 and 55 min post-administration of IN-OT, while peak concentration in the cerebrospinal fluid has been determined to be at 75 min. CONCLUSION: The current level of evidence is moderate showing no effect of IN-OT on AB or ER in AN. However, brain exposure may not have been sufficient which future studies with IN-OT need to ensure by considering dose and dose-to-task interval.

Acute methylphenidate administration reduces cocaine-cue attentional bias.

Mechanistic research on behavioral processes underlying substance use disorder might help identify novel targets for interventions development. Drug-related attentional bias and response inhibition deficits have received a great deal of consideration in substance use research, broadly, and cocaine use research, specifically. Studies investigating pharmacological mechanisms that may ameliorate, or further impair, these behaviors relevant to cocaine use are relatively lacking. This study evaluated the impact of acute administration of methylphenidate, a dopamine-favoring reuptake inhibitor, on both gaze-related cocaine-cue-attentional bias and cocaine-cue related disruptions in response inhibition among individuals with cocaine use disorder. Participants (N = 12; 33% female) completed a within-subject, outpatient, acute dosing study. Two sessions were completed in which methylphenidate (60 mg) or placebo were administered followed by completion of an attentional bias task using eye-tracking technology and neutral-cue and cocaine-cue response inhibition tasks. Subjective and physiological effects were also recorded. Significant cocaine cue attentional bias and response inhibition failures were observed during placebo administration. Acute methylphenidate administration reduced cocaine-cue attentional bias as measured by cocaine-cue gaze fixations (dz = 1.04; Bayes Factor = 12.37). No statistically significant effects of methylphenidate were observed on response inhibition (Bayes Factors = 0.17-1.04). Methylphenidate produced prototypical subjective and physiological effects. Although the small sample should be considered, these findings indicate acute manipulation of dopaminergic activity reduced cue-related attentional allocation related to cocaine use disorder. Future research evaluating alternative dopaminergic agents and applications within a clinical setting are needed to determine the clinical significance of targeting this neurobehavioral mechanism.

The BDNF Val66Met Polymorphism Moderates the Relationship Between Posttraumatic Stress Disorder and Trauma Script-evoked Attentional Bias to Cocaine Cues Among Patients with Cocaine Dependence.

There is extensive variability in cocaine-related attentional bias (AB) following trauma script exposure among cocaine-dependent (CD) patients with posttraumatic stress disorder (PTSD). Therefore, research is needed to identify the specific PTSD-CD patients most likely to exhibit an AB to cocaine cues. A common polymorphism in brain-derived neurotrophic factor (BDNF), Val66met, is associated with risk for stimulant addiction, and thus, was examined as a moderator of the association between PTSD and cocaine-related AB following trauma script exposure in this study. Adult CD patients with (n = 17) and without (n = 28) PTSD were exposed to a personalized trauma script, followed by a visual dot-probe task assessing cocaine-related AB. Task response times were used to examine traditionally calculated AB scores, as well as trial level bias scores (TL-BS) that more accurately model the temporal dynamics of AB. PTSD-CD patients homozygous for the BDNF Val/Val genotype exhibited greater bias for attending to cocaine-related stimuli following trauma script exposure than those carrying the Met allele. The PTSD by BDNF interaction did not predict response time variability on trials for which only neutral stimuli were presented, thus increasing confidence that the observed effect is specific to cocaine-related stimuli. PTSD-CD patients homozygous for the BDNF Val/Val genotype may be at particularly high risk for negative clinical outcomes (e.g., relapse, treatment dropout) as a function of prolonged attentional engagement with cocaine cues when exposed to trauma reminders.

The role of affect, emotion management, and attentional bias in young adult drinking: An experience sampling study.

RATIONALE: Coping with negative affect is central to several prominent etiological models of alcohol use. These models posit that alcohol use becomes negatively reinforced due to its ability to alleviate negative affect. However, there have been mixed findings when testing this association at the event-level. OBJECTIVES: The current experience sampling study sought to clarify this by testing if (1) within-person changes in the perceived difficulty of managing emotional distress is a significant predictor of alcohol consumption, over and above levels negative and positive affect and (2) whether acute changes in affective experiences give rise to increased attentional bias toward alcohol-related cues in the environment and if attentional bias mediates the association between difficulty managing emotions and alcohol consumption. Participants were 92 college students aged 18-25, who drink alcohol at least moderately. METHODS: Participants completed 28 days of experiencing sampling measures on their mood, difficulty managing emotions, alcohol-related attentional biases, and drinking. RESULTS: Findings showed that neither negative affect nor difficult managing emotions had significant effects on alcohol use. However, positive affect exhibited the expected associations with both attentional biases and drinking. State positive affect predicted acute increases in attentional biases and drinking, whereas trait positive affect was inversely associated with trait attentional biases and alcohol use. Alcohol-related attentional biases exhibited significant within-person variance; however, its relationship with drinking was only significant when the constructs were assessed concurrently at night and did not mediate the relationship between affect and alcohol use. CONCLUSIONS: Results highlight the importance of positive affect in this population.

Effects of combined coffee and alcohol use over cigarette demand among treatment-seeking smokers.

OBJECTIVE: This study is aimed at comparing the relative reinforcing efficacy (RRE) of nicotine though CPT performance in function of alcohol and coffee consumption of treatment-seeking smokers. MATERIAL AND METHODS: A total of 88 treatment-seeking smokers (60.2 % female) completed the CPT. A multivariate analysis of variance (MANOVA) was used to compare alcohol (consumers and abstainers of alcohol) and coffee intake (high coffee consumers and low coffee consumers) on CPT indices. RESULTS: Univariate effects of coffee × alcohol use interaction were significant for elasticity [F (1, 83) = 4.9435, p = .038, η2 = .051] and intensity [F (1, 83) = 6.972, p = .01, η2 = .077]. CONCLUSIONS: Alcohol and coffee use is associated with an elevated cigarette demand among treatment-seeking smokers. This finding suggests the need for specific interventions to reduce alcohol and coffee use in order to increase the effectiveness of treatments for smoking cessation.

A pilot study investigating the influence of oxytocin on attentional bias to food images in women with bulimia nervosa or binge eating disorder.

BACKGROUND: Previous research has found that exogenous oxytocin administration has the potential to modulate attentional biases in women with anorexia nervosa. Recent work has indicated that attentional biases to food may reinforce the recurrent binge eating behaviour characterising bulimia nervosa and binge eating disorder. To date, however, no study has yet investigated the effect of oxytocin on attentional biases to palatable food in women with bulimia nervosa and binge eating disorder. METHODS: The present study employed a single-session cross-over design to test the hypothesis that a divided dose of 64 IU of intranasal oxytocin, administered as one intranasal dose of 40 IU of oxytocin followed by a top-up of 24 IU of oxytocin 80 minutes later, vs placebo administration administered in the same dosing schedule would reduce attentional biases towards food images in a dot probe task. We hypothesised that oxytocin administration would reduce vigilance towards food to a greater degree in women with bulimia nervosa or binge eating disorder vs healthy comparison women. Twenty-five women with bulimia nervosa or binge eating disorder and 27 comparison women without history of an eating disorder were recruited to take part in the study. RESULTS: In contrast to our hypothesis, there was no main effect of diagnosis on attentional bias to food (fixed effect = 5.70, P = 0.363), nor a significant interaction between diagnosis and drug condition (fixed effect =-14.80, P = 0.645). There was a main effect of drug condition, such that oxytocin increased vigilance towards food vs neutral images in the dot probe task (fixed effect = 10.42, P = 0.044). A correlation analysis revealed that this effect was moderated by attentional bias in the placebo condition, such that greater avoidance of food stimuli in the placebo condition was associated with a greater increase in vigilance induced by oxytocin. CONCLUSIONS: The findings of the present study add to a mixed body of literature investigating the therapeutic effects of oxytocin in women. Future research would benefit from dose-response studies investigating the optimal dose of oxytocin for modulating the attentional processing of palatable food in populations with eating disorders.

Conflicting rewards: effects of task goals on attention for alcohol cues.

Research has shown that temporary task goals capture more attention than negative, threatening cues, even in anxious individuals. In the current study, we investigated whether temporary task goals would also capture more attention than alcohol-related cues. In Experiment 1, 59 hazardous drinkers performed both a modified dot-probe and a flanker task in which temporary goal- and alcohol-relevant stimuli were presented together. Results of the dot-probe task confirmed an attentional bias towards goal-relevant stimuli in the presence of alcohol cues. This effect was absent in a modified flanker task, although there was a general slowing when the targets appeared on top of goal-relevant stimuli, suggesting that goal-related backgrounds captured more attention than alcohol backgrounds. In Experiment 2, we replicated the dot-probe procedure in 29 hazardous drinkers who had been exposed to a prime dose of alcohol prior to performing the task. Our findings indicate that temporary goal stimuli are more salient than alcohol cues, which might lead the way to novel clinical applications.

Orbitofrontal cortex is selectively activated in a primate model of attentional bias to cocaine cues.

Attentional bias to drug-associated cues correlates with extent of current use, and risk of relapse among those attempting abstinence. Electroencephalogram (EEG) and functional imaging measures in clinical studies have previously investigated the neural basis of attentional bias, but the lack of animal models precluded investigation at the single-unit level. To complement results obtained from clinical studies, we have employed a non-human primate model of attentional bias to cocaine cues while simultaneously recording single-unit activity in cortical and striatal regions implicated in reward processing. Rhesus macaques conditioned to associate particular colors with cocaine or water reward performed an attentional bias task, in which those colors served as irrelevant distractors. Concurrently, multiple electrode arrays for recording single-unit activity were acutely implanted into the orbitofrontal cortex, anterior cingulate cortex, dorsal anterior striatum, and ventral striatum. As in clinical studies, attentional bias was indicated by elongated response times on trials with cocaine-associated distractors compared with trials with water-associated, or control unconditioned distractors. In both animals studied, across an unbiased sample of neurons, the orbitofrontal cortex differentiated distractor condition by the proportion of single-units activated, as well as by population response. In one of the two, the anterior cingulate cortex did as well, but neither striatal region did in either animal. These direct measures of single-unit activity in a primate model complement clinical imaging observations suggesting that cortical mechanisms, especially in orbitofrontal cortex, are likely involved in attentional bias to cocaine-associated environmental cues.

Attentional bias towards cannabis cues in cannabis users: A systematic review and meta-analysis.

INTRODUCTION: Attentional bias, the automatic selective attentional orientation towards drug-related stimuli is well demonstrated in substance users. However, attentional bias studies of cannabis users specifically have thus far been inconclusive. Thus, the aim of this systematic review and meta-analysis was to synthesize the currently available literature regarding cannabis related attentional bias in cannabis users. METHODS: Literature search and selection was carried out, following the PRISMA guidelines, with all included studies investigating the relationship between cannabis use and attentional bias towards cannabis cues. RESULTS: Fourteen manuscripts, reporting on 1271 participants (cannabis users n = 1044; controls n = 217), were considered for the systematic-review and majority were included in a meta-analysis. Studies reviewed used three types of attentional bias tasks: pictorial stimuli, word stimuli, and non-cannabis stimuli tasks. Greater attentional bias towards cannabis pictures (d = 0.42, P < 0.0001) and words (d = 0.63, P = 0.03) as well as both types of stimuli overall (d = 0.53, P < 0.0001) was observed in cannabis users compared to controls, though there was evidence of significant heterogeneity for both word stimuli and overall meta-analysis. Bigger effect sizes were associated with shorter durations of exposure to cannabis stimuli suggesting mainly automatic orientating rather than controlled attention processing. CONCLUSIONS: These findings suggest that cannabis users display greater attentional bias towards cannabis cues, likely an automatic process, than control groups. Future studies employing shorter exposure durations may validate attentional bias as a treatment target for the development of interventions in people with cannabis use disorder.

Use of an estradiol-based combined oral contraceptives has no influence on attentional bias or depressive symptoms in healthy women.

Combined oral contraceptive (COC) use is associated with small, albeit significant, increases in mental symptom scores, predominantly irritability, depressed mood, and anxiety. Yet, randomized prospective trials are needed to better characterize the women at risk for COC-induced negative mood change. Thus, the primary aim of this sub-study to a placebo-controlled randomized trial was to determine whether COC use influences emotional interference by negative and positive stimuli. Secondly, we wanted to evaluate what factors would predict depressive symptoms at the end of the trial, taking personality factors, history of mental disorders and other demographic factors into account. Sixty-nine women were included, randomized to three cycles of treatment with a COC (1.5 mg estradiol and 2.5 mg nomegestrolacetate) or placebo. An emotional verbal Stroop task was used to measure interference of emotional stimuli, in which participants were asked to only name the color of a presented word, while ignoring the meaning of the word. Four different word categories were used; neutral, positive, depression, and anxiety. For the second aim of the study, rating on the Montgomery-Åsberg Depression Rating Scale during the final days of the trial was used as outcome. We found no interaction between emotional verbal Stroop word category and treatment, indicating that COC treatment did not evoke any differences in emotional interference to the three word categories. Significant predictors for depressive symptoms at the end of the trial were trait anxiety at baseline and prior adverse mood effects by hormonal contraceptive use. Treatment (i.e. whether women had been treated with the COC or placebo) did not play a role in predicting depression scores at the end of the trial. In conclusion, we found no evidence that combined oral contraceptive use is associated with impaired cognitive-emotional processing. Instead, the main predictors of self-rated depression at the end of the trial were baseline trait anxiety and previous mental symptoms during hormonal contraceptive use.

Alcohol administration reduces attentional bias to alcohol-related but not food-related cues: Evidence for a satiety hypothesis.

Attentional bias to alcohol is a well-documented effect whereby drinkers allocate greater visual attention toward alcohol-related stimuli rather than nonappetitive, neutral stimuli. Some recent research has shown that acute administration of alcohol temporarily reduces attentional bias to alcohol cues, possibly because alcohol consumption satiates the motivation to drink. However, the specificity of this effect has not been tested, and so it is unclear whether reduced attentional bias following alcohol is specific to alcohol-related stimuli or whether attention to other appetitive stimuli is also reduced (e.g., food). This study tested the degree to which acute alcohol administration selectively reduced attentional bias to alcohol-related but not to food-related cues in a group of 23 healthy young adults who reported consuming alcohol roughly twice per week. Attentional bias to alcohol-related and food-related cues was tested using visual dot probe tasks following 2 active doses of alcohol, .30 g/kg and .65 g/kg, and a placebo. Results showed that attentional bias, measured as fixation time to stimuli on the visual probe tasks, to alcohol cues declined in a dose-dependent manner, whereas attentional bias to food cues was unaffected by the doses. The evidence suggests that alcohol consumption specifically reduces attentional bias to alcohol-related stimuli whereas bias to other appetitive stimuli remains intact. Evidence that alcohol consumption reduces attentional bias specifically to alcohol cues lends further credibility to the satiation theory and to the utility of attentional bias as an indicator of acute and transient changes in an individual's motivation to use alcohol. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Effects of MDMA on attention to positive social cues and pleasantness of affective touch.

The psychostimulant drug ±3,4-methylenedioxymethamphetamine (MDMA) reportedly produces distinctive feelings of empathy and closeness with others. MDMA increases social behavior in animal models and has shown promise in psychiatric disorders, such as autism spectrum disorder (ASD) and post-traumatic stress disorder (PTSD). How it produces these prosocial effects is not known. This behavioral and psychophysiological study examined the effects of MDMA, compared with the prototypical stimulant methamphetamine (MA), on two measures of social behavior in healthy young adults: (i) responses to socially relevant, "affective" touch, and (ii) visual attention to emotional faces. Men and women (N = 36) attended four sessions in which they received MDMA (0.75 or 1.5 mg/kg), MA (20 mg), or a placebo in randomized order under double-blind conditions. Responses to experienced and observed affective touch (i.e., being touched or watching others being touched) were assessed using facial electromyography (EMG), a proxy of affective state. Responses to emotional faces were assessed using electrooculography (EOG) in a measure of attentional bias. Subjective ratings were also included. We hypothesized that MDMA, but not MA, would enhance the ratings of pleasantness and psychophysiological responses to affective touch and increase attentional bias toward positive facial expressions. Consistent with this, we found that MDMA, but not MA, selectively enhanced ratings of pleasantness of experienced affective touch. Neither drug altered the ratings of pleasantness of observed touch. On the EOG measure of attentional bias, MDMA, but not MA, increased attention toward happy faces. These results provide new evidence that MDMA can enhance the experience of positive social interactions; in this case, pleasantness of physical touch and attentional bias toward positive facial expressions. The findings are consistent with evidence that the prosocial effects are unique to MDMA relative to another stimulant. Understanding the behavioral and neurobiological processes underlying the distinctive social effects of MDMA is a key step to developing the drug for psychiatric disorders.

Sweet cognition: The differential effects of glucose consumption on attentional food bias in individuals of lean and obese status.

In general, glucose consumption improves cognitive performance; however, it is unknown whether glucose specifically alters attentional food bias, and how this process may vary by BMI status. We hypothesized that glucose consumption would increase attentional food bias among individuals of obese BMI status more so than among individuals of lean BMI status. Participants (N = 35) completed the n-back, a working memory task modified to assess attentional food bias (ATT-Food), under fasting and glucose challenge conditions. We computed pre-post changes in ATT-Food, blood glucose and insulin (∆BG & ∆BI), and perceived task-stress (∆stress). After the second cognitive test and blood draw, participants ate lunch and completed a "taste test" of highly palatable foods, and we recorded food consumption. Pre-post changes in ATT-Food were greater among participants of obese (relative to lean) BMI status (F(1,33) = 5.108, p = .031). Greater ∆ATT-Food was significantly associated with greater ∆BG (r = .462, p = .007) and reduced ∆stress (r =-.422, p = .011), and marginally associated with greater taste-test eating (r =.325, p = .057), but was not associated with ∆BI. Our findings suggest that individuals of obese BMI status may exhibit "sweet cognition," as indexed by greater attentional food bias following glucose ingestion, relative to individuals of lean BMI status. Among individuals of obese BMI status, sweet cognition may arise from difficulty broadening attention toward non-food cues after consuming a high glucose load, thereby potentially perpetuating sugar consumption. If confirmed by further research, measures of sweet cognition may help identify individuals with a phenotype of risk for obesity and greater sugar consumption, who may benefit from tailored interventions.

Exploring the fMRI based neural correlates of the dot probe task and its modulation by sex and body odor.

The dot probe task implicitly cues attention via emotional information, an effect which is especially pronounced for threat-related cues. However, several questions remain unexplored. The first one is whether chemosignals like the androgen-derivative androstadienone can influence such attentional biases. Second, few studies have addressed sex differences regarding attentional biases. Finally, the neural correlates of these potential behavioral effects based on functional magnetic resonance imaging (fMRI) are not known. In two experiments we aimed to answer these questions. A total of 159 healthy individuals (58 oral-contraceptive-users, 42 luteal women, 59 men) were tested. In experiment 1 (behavioral study) we examined attentional biases behaviorally, while in experiment 2 (fMRI study) the dot probe task was complemented by fMRI. Our results provide robust evidence that in healthy participants fearful but not angry or happy faces lead to a strong general attentional bias. Elucidating the neural basis of this effects points to an early processing advantage in bilateral thalamus for valid compared to invalid cued fear. However, this finding was limited to those participants with the strongest attentional biases and was not linked to behavioral measures. Furthermore, no consistent sex or group differences existed neither did the putative human chemosignal androstadienone reliably modulate attentional biases or change neural processing.