Affective imagery boosts the reward related delta power in hazardous drinkers.

The Reward Positivity (RewP) is an event-related potential component with a delta band spectral representation that is elicited by reward receipt. Evidence suggests that RewP is modulated by both reward probability as well as affective valuation ("liking"). Here we determined whether RewP is a marker of enhanced hedonic salience of alcohol images in hazardous drinkers. We recruited 54 participants (Hazardous Drinkers = 28, Control = 26) who completed a reinforcement learning task with affective versus alcohol imagery during feedback. The learning task used images of puppies vs. alcohol paired with reinforcing feedback. Both groups rated categories of affective images (puppies, scenery, babies, neutral) similarly, but the hazardous drinking group rated alcohol significantly higher. There were no group differences in performance or in RewP amplitudes, even as a function of alcohol imagery. Contrary to prior findings, we did not observe a significant correlation between alcohol image rating and alcohol-specific RewP amplitude, although we did observe this relationship with the alcohol-specific delta band spectral representation of RewP. Within hazardous drinking group, there was significant correlation between hazardous drinking (AUDIT score) and alcohol-specific RewP indicating an inter-individual influence of drinking habits on affect specific RewP. These findings suggest a domain-specific enhancement of reward responsiveness in hazardous drinkers.

Electrophysiological Markers of Aberrant Cue-Specific Exploration in Hazardous Drinkers.

Background: Hazardous drinking is associated with maladaptive alcohol-related decision-making. Existing studies have often focused on how participants learn to exploit familiar cues based on prior reinforcement, but little is known about the mechanisms that drive hazardous drinkers to explore novel alcohol cues when their value is not known. Methods: We investigated exploration of novel alcohol and non-alcohol cues in hazardous drinkers (N = 27) and control participants (N = 26) during electroencephalography (EEG). A normative computational model with two free parameters was fit to estimate participants' weighting of the future value of exploration and immediate value of exploitation. Results: Hazardous drinkers demonstrated increased exploration of novel alcohol cues, and conversely, increased probability of exploiting familiar alternatives instead of exploring novel non-alcohol cues. The motivation to explore novel alcohol stimuli in hazardous drinkers was driven by an elevated relative future valuation of uncertain alcohol cues. P3a predicted more exploratory decision policies driven by an enhanced relative future valuation of novel alcohol cues. P3b did not predict choice behavior, but computational parameter estimates suggested that hazardous drinkers with enhanced P3b to alcohol cues were likely to learn to exploit their immediate expected value. Conclusions: Hazardous drinkers did not display atypical choice behavior, different P3a/P3b amplitudes, or computational estimates to novel non-alcohol cues-diverging from previous studies in addiction showing atypical generalized explore-exploit decisions with non-drug-related cues. These findings reveal that cue-specific neural computations may drive aberrant alcohol-related decision-making in hazardous drinkers-highlighting the importance of drug-relevant cues in studies of decision-making in addiction.

The Effects of Functionally Guided, Connectivity-Based rTMS on Amygdala Activation.

While repetitive transcranial magnetic stimulation (rTMS) is widely used to treat psychiatric disorders, innovations are needed to improve its efficacy. An important limitation is that while psychiatric disorders are associated with fronto-limbic dysregulation, rTMS does not have sufficient depth penetration to modulate affected subcortical structures. Recent advances in task-related functional connectivity provide a means to better link superficial and deeper cortical sources with the possibility of increasing fronto-limbic modulation to induce stronger therapeutic effects. The objective of this pilot study was to test whether task-related, connectivity-based rTMS could modulate amygdala activation through its connectivity with the medial prefrontal cortex (mPFC). fMRI was collected to identify a node in the mPFC showing the strongest connectivity with the amygdala, as defined by psychophysiological interaction analysis. To promote Hebbian-like plasticity, and potentially stronger modulation, 5 Hz rTMS was applied while participants viewed frightening video-clips that engaged the fronto-limbic network. Significant increases in both the mPFC and amygdala were found for active rTMS compared to sham, offering promising preliminary evidence that functional connectivity-based targeting may provide a useful approach to treat network dysregulation. Further research is needed to better understand connectivity influences on rTMS effects to leverage this information to improve therapeutic applications.

Neighborhood Deprivation Shapes Motivational-Neurocircuit Recruitment in Children.

Implementing motivated behaviors on the basis of prior reward is central to adaptive human functioning, but aberrant reward-motivated behavior is a core feature of neuropsychiatric illness. Children from disadvantaged neighborhoods have decreased access to rewards, which may shape motivational neurocircuits and risk for psychopathology. Here, we leveraged the unprecedented neuroimaging data from the Adolescent Brain Cognitive Development (ABCD) study to test the hypothesis that neighborhood socioeconomic disadvantage shapes the functional recruitment of motivational neurocircuits in children. Specifically, via the ABCD study's monetary-incentive-delay task (N = 6,396 children; age: 9-10 years), we found that children from zip codes with a high Area Deprivation Index demonstrate blunted recruitment of striatum (dorsal and ventral nuclei) and pallidum during reward anticipation. In fact, blunted dorsal striatal recruitment during reward anticipation mediated the association between Area Deprivation Index and increased attention problems. These data reveal a candidate mechanism driving elevated risk for psychopathology in children from socioeconomically disadvantaged neighborhoods.

Utilizing the commodity purchase task to evaluate behavioral economic demand for illicit substances: a review and meta-analysis.

BACKGROUND ANDAIMS: The commodity purchase task is a simulated demand procedure that is easy and quick to complete (< 5 minutes) as well as adaptable for remote delivery and use with varied study populations. The purpose of this meta-analysis was to synthesize research using the commodity purchase task with illicit substances to evaluate the magnitude of omnibus effects sizes and moderators of the correlation of demand indices with quantity-frequency (QF) and severity measures. DESIGN: Random-effects meta-analyses and meta-regressions involving studies with cross-sectional correlational designs. SETTING AND PARTICIPANTS: Eleven studies, 10 outcomes and 2146 participants from two countries (USA and UK) published up to 1 October 2018. MEASUREMENTS: Omnibus effect sizes (correlation coefficients) of five demand indices from the commodity purchase task [intensity (unconstrained consumption), elasticity (price sensitivity), Omax (maximum expenditure), Pmax (price at maximum expenditure) and breakpoint (first price of zero consumption)] with QF and severity measures. Meta-regression models tested moderators of effect sizes (i.e. sample age and sex composition, commodity type and number of prices used in the commodity purchase task). FINDINGS: Significant omnibus effect sizes were observed with QF and severity measures for intensity (r = 0.32/0.28, QF/severity, respectively), elasticity (r = -0.14/-0.18), Omax (r = 0.30/0.29) and breakpoint (r = 0.17/0.22) values. Pmax was only significantly associated with severity measures (r = 0.15). The percentage of female participants and number of prices used in the purchase task significantly moderated Pmax and breakpoint effect-size estimates in that stronger associations were observed in samples with a greater percentage of women and in studies using tasks with more price points. Commodity type (cannabis versus cocaine) did not significantly moderate associations involving any demand index. CONCLUSIONS: Behavioral economic demand as measured by the commodity purchase task is consistently correlated with measures of illicit substance use quantity-frequency and severity.

Antarctic offshore polynyas linked to Southern Hemisphere climate anomalies.

Offshore Antarctic polynyas-large openings in the winter sea ice cover-are thought to be maintained by a rapid ventilation of deep-ocean heat through convective mixing. These rare phenomena may alter abyssal properties and circulation, yet their formation mechanisms are not well understood. Here we demonstrate that concurrent upper-ocean preconditioning and meteorological perturbations are responsible for the appearance of polynyas in the Weddell Sea region of the Southern Ocean. Autonomous profiling float observations-collected in 2016 and 2017 during the largest polynyas to form near the Maud Rise seamount since 1976-reveal that the polynyas were initiated and modulated by the passage of severe storms, and that intense heat loss drove deep overturning within them. Wind-driven upwelling of record strength weakened haline stratification in the upper ocean, thus favouring destabilization in 2016 and 2017. We show that previous Weddell polynyas probably developed under similarly anomalous conditions, which are associated with a mode of Southern Hemisphere climate variability that is predicted to strengthen as a result of anthropogenic climate change.

Reliability and validity of the Brief DSM-5 Alcohol Use Disorder Diagnostic Assessment: A systematic replication in a crowdsourced sample.

Effectively and efficiently identifying alcohol use disorder (AUD) is an essential goal for researchers and clinicians alike. To date, there are a limited number of self-reported tools specifically designed for evaluating DSM-5 criteria for AUD. The Brief DSM-5 AUD Diagnostic Assessment is a recently created participant self-reported measure with demonstrated reliability and validity in college student populations. The purpose of this study was to replicate and extend these findings by evaluating the psychometric properties of the Brief DSM-5 AUD Diagnostic Assessment in a geographically diverse adult sample with varying alcohol use history. Participants (N = 1986) were sampled from the crowdsourcing website Amazon Mechanical Turk (mTurk). The Brief DSM-5 AUD Diagnostic Assessment was completed to evaluate scale reliability and validity. A subset of individuals with answers indicative of AUD (N = 448) also completed a battery of standardized alcohol use questionnaires for additional validity assessments. High internal consistency reliability was observed (α = 0.92) along with strong item-total correlations. Convergent validity was supported by significant positive relationships between diagnostic category and measures of alcohol use consumption and severity. Modest relationships that were generally not statistically significant were observed with soda use measures supporting discriminant validity. AUD severity remained a significant predictor of alcohol use measures after accounting for AUDIT scores, thereby establishing incremental validity. These findings collectively support the Brief DSM-5 AUD Diagnostic Assessment as a reliable, valid, and rapid self-report tool for evaluating DSM-5 AUD in diverse research and clinical settings.