Ecological momentary assessment of delay discounting, reward valuation, and craving in very light cigarette users.

Heightened delay discounting has been linked to adverse smoking cessation outcomes, including among light cigarette users. Few studies have evaluated delay discounting's proposed mechanism, preference reversal (concurrent increases in valuation of/craving for desired objects), and none have done so in naturalistic settings. We examined how person-level delay discounting moderated the within-person association between cigarette valuation and craving among very light daily cigarette users who were financially incentivized to abstain. Forty participants completed a baseline delay-discounting task and intermittent ratings of cigarette valuation and craving during the incentivized abstinence attempt. Subjects earned monetary rewards for abstinence on a descending schedule (e.g., $20 on Days 1 and 2 and $2.50 on Days 9 and 10). Consistent with preference reversals, there was a positive association between cigarette valuation and craving. This relation was moderated by delay discounting (stronger among those with low discounting rates) and by monetary reinforcement amount (stronger on days with low reinforcement). Additionally, subjects were more likely to report stronger cravings on days with high monetary reinforcement, with this effect moderated by delay discounting (stronger among those with low discounting rates). The results suggest that heightened delay discounting may not confer risk for preference reversal among very light daily cigarette users who are attempting abstinence.

Eating in the Absence of Hunger is a stable predictor of adiposity gains in middle childhood.

BACKGROUND: Eating in the Absence of Hunger (EAH) is a behavioral phenotype of pediatric obesity characterized by consumption of palatable food beyond hunger. Studies in children have identified EAH as stable over time, but findings are unclear on whether it predicts development of adiposity, particularly in middle childhood, a period of increased autonomy over food choice. OBJECTIVE: We hypothesized that EAH would remain stable and be associated with increased adiposity over a ≥1-year prospective study in 7-8-year-old children without obesity. Secondary hypotheses tested whether physical activity moderated the impact of EAH on adiposity. METHODS: Children (n=72, age 7.8±0.6 years; BMI%<90th), in a 7-visit longitudinal study, had EAH, adiposity, and physical activity assessed at baseline (Time 1-T1) and follow-up (Time 2-T2). EAH was determined by measuring children's intake from 9 energy-dense (>3.9 kcal/g) sweet and savory foods during a 10-minute access period following intake of a standard meal eaten to satiation. Adiposity was measured with dual-energy X-ray absorptiometry (DXA), with an outcome of fat mass index (FMI; fat mass/ht in m-sq). Seven days of wrist-worn Actigraphy quantified moderate-to-vigorous-physical activity (MVPA) and sedentary time. RESULTS: EAH had moderate stability across timepoints (ICC=0.54). ICCs were stronger for sweet (ICC=0.53) than savory (ICC=0.38) foods. Linear regression predicting 1-yr change in FMI (adjusted for income, parent education, sex, time to follow-up, T2 Tanner stage, maternal weight status, and baseline adiposity) found that both total and sweet food EAH at baseline predicted increases in adiposity (p<0.05 for both). EAH and adiposity were negatively correlated among children with high MVPA and low sedentary time. CONCLUSIONS: These findings show that EAH is a stable predictive phenotype of increases in adiposity over 1 year among youth in middle childhood, although activity related behaviors may moderate this effect. If replicated, targeting EAH as part of interventions may prevent excess adiposity gain. CLINICAL TRIAL REGISTRY: The data was obtained from the Food and Brain study (ClinicalTrials.gov) NCT03341247.

PACE: a Novel Eating Behavior Phenotype to Assess Risk for Obesity in Middle Childhood.

BACKGROUND: Behavioral phenotypes that predict future weight gain are needed to identify children susceptible to obesity. OBJECTIVES: This prospective study developed an eating behavior risk score to predict change in adiposity over 1 y in children. METHODS: Data from 6 baseline visits (Time 1, T1) and a 1-y follow-up visit (Time 2, T2) were collected from 76, 7- to 8-y-old healthy children recruited from Central Pennsylvania. At T1, children had body mass index (BMI) percentiles <90 and were classified with either high (n = 33; maternal BMI ≥30 kg/m2) or low (n = 43; maternal BMI ≤25 kg/m2) familial risk for obesity. Appetitive traits and eating behaviors were assessed at T1. Adiposity was measured at T1 and T2 using dual-energy x-ray absorptiometry, with a main outcome of fat mass index (FMI; total body fat mass divided by height in meters squared). Hierarchical linear regressions determined which eating measures improved prediction of T2 FMI after adjustment for covariates in the baseline model (T1 FMI, sex, income, familial risk, and Tanner stage). RESULTS: Four eating measures-Portion susceptibility, Appetitive traits, loss of control eating, and eating rate-were combined into a standardized summary score called PACE. PACE improved the baseline model to predict 80% variance in T2 FMI. PACE was positively associated with the increase in FMI in children from T1 to T2, independent of familial risk (r = 0.58, P < 0.001). Although PACE was higher in girls than boys (P < 0.05), it did not differ by familial risk, income, or education. CONCLUSIONS: PACE represents a cumulative eating behavior risk score that predicts adiposity gain over 1 y in middle childhood. If PACE similarly predicts adiposity gain in a cohort with greater racial and socioeconomic diversity, it will inform the development of interventions to prevent obesity. This trial was registered at clinicaltrials.gov as NCT03341247.

The Cerebellar Response to Visual Portion Size Cues Is Associated with the Portion Size Effect in Children.

The neural mechanisms underlying susceptibility to eating more in response to large portions (i.e., the portion size effect) remain unclear. Thus, the present study examined how neural responses to portion size relate to changes in weight and energy consumed as portions increase. Associations were examined across brain regions traditionally implicated in appetite control (i.e., an appetitive network) as well as the cerebellum, which has recently been implicated in appetite-related processes. Children without obesity (i.e., BMI-for-age-and-sex percentile < 90; N = 63; 55% female) viewed images of larger and smaller portions of food during fMRI and, in separate sessions, ate four meals that varied in portion size. Individual-level linear and quadratic associations between intake (kcal, grams) and portion size (i.e., portion size slopes) were estimated. The response to portion size in cerebellar lobules IV-VI was associated with the quadratic portion size slope estimated from gram intake; a greater response to images depicting smaller compared to larger portions was associated with steeper increases in intake with increasing portion sizes. Within the appetitive network, neural responses were not associated with portion size slopes. A decreased cerebellar response to larger amounts of food may increase children's susceptibility to overeating when excessively large portions are served.

Does 'portion size' matter? Brain responses to food and non-food cues presented in varying amounts.

Larger portions of food elicit greater intake than smaller portions of food, particularly when foods are high in energy density (kcal/g; ED). The neural mechanisms underlying this effect remain unclear. The present study used fMRI to assess brain activation to food (higher-ED, lower-ED) and non-food (office supplies) images presented in larger and smaller (i.e., age-appropriate) amounts in 61, 7-8-year-olds (29 male, 32 female) without obesity. Larger amounts of food increased activation in bilateral visual and right parahippocampal areas compared to smaller amounts; greater activation to food amount (larger > smaller) in this cluster was associated with smaller increases in food intake as portions increased. Activation to amount (larger > smaller) was stronger for food than office supplies in primary and secondary visual areas, but, for office supplies only, extended into bilateral parahippocampus, inferior parietal cortex, and additional visual areas (e.g., V7). Activation was greater for higher-vs. lower-ED food images in ventromedial prefrontal cortex for both larger and smaller amounts of food; however, this activation extended into left lateral orbital frontal cortex for smaller amounts only. Activation to food cues did not differ by familial risk for obesity. These results highlight potentially distinct neural pathways for encoding food energy content and quantity.

Parameter Space and Potential for Biomarker Development in 25 Years of fMRI Drug Cue Reactivity: A Systematic Review.

Importance: In the last 25 years, functional magnetic resonance imaging drug cue reactivity (FDCR) studies have characterized some core aspects in the neurobiology of drug addiction. However, no FDCR-derived biomarkers have been approved for treatment development or clinical adoption. Traversing this translational gap requires a systematic assessment of the FDCR literature evidence, its heterogeneity, and an evaluation of possible clinical uses of FDCR-derived biomarkers. Objective: To summarize the state of the field of FDCR, assess their potential for biomarker development, and outline a clear process for biomarker qualification to guide future research and validation efforts. Evidence Review: The PubMed and Medline databases were searched for every original FDCR investigation published from database inception until December 2022. Collected data covered study design, participant characteristics, FDCR task design, and whether each study provided evidence that might potentially help develop susceptibility, diagnostic, response, prognostic, predictive, or severity biomarkers for 1 or more addictive disorders. Findings: There were 415 FDCR studies published between 1998 and 2022. Most focused on nicotine (122 [29.6%]), alcohol (120 [29.2%]), or cocaine (46 [11.1%]), and most used visual cues (354 [85.3%]). Together, these studies recruited 19 311 participants, including 13 812 individuals with past or current substance use disorders. Most studies could potentially support biomarker development, including diagnostic (143 [32.7%]), treatment response (141 [32.3%]), severity (84 [19.2%]), prognostic (30 [6.9%]), predictive (25 [5.7%]), monitoring (12 [2.7%]), and susceptibility (2 [0.5%]) biomarkers. A total of 155 interventional studies used FDCR, mostly to investigate pharmacological (67 [43.2%]) or cognitive/behavioral (51 [32.9%]) interventions; 141 studies used FDCR as a response measure, of which 125 (88.7%) reported significant interventional FDCR alterations; and 25 studies used FDCR as an intervention outcome predictor, with 24 (96%) finding significant associations between FDCR markers and treatment outcomes. Conclusions and Relevance: Based on this systematic review and the proposed biomarker development framework, there is a pathway for the development and regulatory qualification of FDCR-based biomarkers of addiction and recovery. Further validation could support the use of FDCR-derived measures, potentially accelerating treatment development and improving diagnostic, prognostic, and predictive clinical judgments.

Children at high familial risk for obesity show executive functioning deficits prior to development of excess weight status.

OBJECTIVE: The objective of this study was to determine whether children with healthy weight who vary by familial risk for obesity differ in executive functioning. METHODS: Children (age 7-8 years) without obesity (n = 93, 52% male) who differed by familial risk for obesity (based on maternal weight status) completed go/no-go and stop-signal tasks to assess inhibitory control and an N-back task to assess working memory. Dual energy x-ray absorptiometry measured adiposity. Linear and mixed-effect models assessed unique effects and relative importance analysis-quantified relative effects of familial risk and percent body fat. RESULTS: Children at high compared with low familial risk showed worse inhibitory control; however, child adiposity was not associated with inhibitory control. Both high familial risk and greater child adiposity were associated with worse N-back performance when cognitive demand was high (2-back), but not low (0- and 1-back). The relative effect of familial risk on executive functioning was 2.7 to 16 times greater than the relative effect of percent body fat. CONCLUSIONS: These findings provide initial evidence that deficits in executive functioning may precede the development of obesity in children at high familial risk for this disease. Additional family risk studies are needed to elucidate the pathways through which maternal obesity influences child executive functioning and risk for obesity.

Children with lower ratings of executive functions have a greater response to the portion size effect.

Deficits in executive functions (EFs), a set of cognitive processes related to self-regulation, are associated with the development of obesity. Prior studies from our group showed that lower food-cue related activation in brain regions implicated in self-regulation was related to a larger portion size effect. We tested the hypothesis that lower EFs in children would be positively related to the portion size effect. Healthy weight children aged 7-8 y (n = 88), who varied by maternal obesity status, participated in a prospective study. At baseline, the parent primarily in charge of feeding completed the Behavior Rating Inventory of Executive Function (BRIEF2) to assess child EFs, including Behavioral (BRI), Emotional (ERI), and Cognitive (CRI) indices. At 4 baseline sessions, children consumed meals in which the portion sizes of foods (pasta, chicken nuggets, broccoli, and grapes) varied by visit (total meal weight of 769, 1011, 1256, or 1492g). Intake increased with increasing portions in a linear trajectory (p < 0.001). EFs moderated the portion size effect such that lower BRI (p = 0.003) and ERI (p = 0.006) were associated with steeper increases in intake as portions increased. As amount of food increased, children in the lowest functioning tertiles for BRI and ERI increased intake by 35% and 36%, respectively, compared to children in the higher tertiles. Increases in intake among children with lower EFs were for higher- but not lower-energy-dense foods. Thus, in healthy weight children who varied by obesity risk, lower parentally reported EFs were associated with a larger portion size effect, and these results were independent of child and parent weight status. Therefore, EFs may be target behaviors that could be strengthened to help children moderate excess intake in response to large portions of energy-dense foods.

Testing the efficacy of real-time fMRI neurofeedback for training people who smoke daily to upregulate neural responses to nondrug rewards.

Although the use of nondrug rewards (e.g., money) to facilitate smoking cessation is widespread, recent research has found that such rewards may be least effective when people who smoke cigarettes are tempted to do so. Specifically, among people who smoke, the neural response to nondrug rewards appears blunted when access to cigarettes is anticipated, and this blunting is linked to a decrease in willingness to refrain from smoking to earn a monetary incentive. Accordingly, methods to enhance the value of nondrug rewards may be theoretically and clinically important. The current proof-of-concept study tested if real-time fMRI neurofeedback training augments the ability to upregulate responses in reward-related brain areas relative to a no-feedback control condition in people who smoke. Adults (n = 44, age range = 20-44) who reported smoking >5 cigarettes per day completed the study. Those in the intervention group (n = 22, 5 females) were trained to upregulate brain responses using feedback of ongoing striatal activity (i.e., a dynamic "thermometer" that reflected ongoing changes of fMRI signal intensity in the striatum) in a single neurofeedback session with three training runs. The control group (n = 22, 5 females) underwent a nearly identical procedure but received no neurofeedback. Those who received neurofeedback training demonstrated significantly greater increases in striatal BOLD activation while attempting to think about something rewarding compared to controls, but this effect was present only during the first training run. Future neurofeedback research with those who smoke should explore how to make neurofeedback training more effective for the self-regulation of reward-related brain activities.

Psychometric evaluation of a Visual Interpersonal Analog Scale.

Interpersonal theory organizes social behavior along dominant (vs. submissive) and warm (vs. cold) dimensions. There is a growing interest in assessing these behaviors in naturalistic settings to maximize ecological validity and to study dynamic social processes. Studies that have assessed interpersonal behavior in daily life have primarily relied on behavioral checklists. Although checklists have advantages, they are discrepant with techniques used to capture constructs typically assessed alongside warmth and dominance, such as affect, which typically rely on adjective descriptors. Further, these checklists are distinct from the methodologies used at the dispositional level, such as personality inventories, which rarely rely on behavioral checklists. The present study evaluates the psychometric performance of interpersonal adjectives presented on a visual analog scale in five different samples. Validity of the Visual Interpersonal Analog scale (VIAS) approach to momentary assessment was evaluated by comparing its performance with an interpersonal behavior checklist and by examining associations among the VIAS Warmth and Dominance scales and other momentary and dispositional constructs. Results were generally consistent with an existing interpersonal behavior checklist at the within-person level but diverged somewhat at the dispositional level. Across the five samples, the VIAS generally performed as hypothesized at both the within- and between-person levels. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Momentary associations between affect and craving as a function of perceived smoking opportunity in young adults smoking 1-5 cigarettes per day: An ecological momentary assessment study.

BACKGROUND: Very light daily smoking (1-5 cigarettes/day) is associated with adverse consequences and is prevalent among young adults. Evidence suggests that perceived smoking opportunity modulates links between affect and craving in adults with heavier smoking patterns (e.g., > 10 cigarettes per day), but there is a lack of similar data in young adults with very light daily smoking patterns. This study addresses this gap by investigating the associations between affect and craving as a function of perceived smoking opportunity under naturalistic conditions. METHODS: Forty-one young adults aged 18-25 (M=21.03, SD=1.75) who reported smoking 1-5 cigarettes per day (M=3.2, SD=1.2) completed intermittent ratings of momentary affective valence and arousal, smoking craving, and perceived smoking opportunity on smartphones five times per day for seven days. RESULTS: Multilevel analyses suggested that when participants felt more pleasant or unpleasant, they were likely to report more intense craving. When smoking opportunity was perceived as high, affective arousal was positively associated with craving; this association was not observed when opportunity to smoke was perceived as low. CONCLUSIONS: These findings indicate that higher momentary intensity of affective valence (both negative and positive) is linked to stronger momentary craving in young adults who report very light daily smoking. Anticipating an opportunity to satisfy craving by smoking may strengthen the association between reported affective arousal and craving in this population. These results highlight the potential benefits of coping with craving (e.g., by regulating affect) for those who engage in light tobacco use, especially in environments with high cigarette availability.

Prenatal androgen influences on the brain: A review, critique, and illustration of research on congenital adrenal hyperplasia.

Sex hormones, especially androgens, contribute to sex and gender differences in the brain and behavior. Organizational effects are particularly important because they are thought to be permanent, reflecting hormone exposure during sensitive periods of development. In human beings, they are often studied with natural experiments in which sex hormones are dissociated from other biopsychosocial aspects of development, such as genes and experiences. Indeed, the greatest evidence for organizational effects on sex differences in human behavior comes from studies of females with congenital adrenal hyperplasia (CAH), who have heightened prenatal androgen exposure, female-typical rearing, and masculinized toy play, activity and career interests, spatial skills, and some personal characteristics. Interestingly, however, neuroimaging studies of females with CAH have revealed few neural mechanisms underlying these hormone-behavior links, with the exception of emotion processing; studies have instead shown reduced gray matter volumes and reduced white matter integrity most consistent with other disease-related processes. The goals of this narrative review are to: (a) describe methods for studying prenatal androgen influences, while offering a brief overview of behavioral outcomes; (b) provide a critical methodological review of neuroimaging research on females with CAH; (c) present an illustrative analysis that overcomes methodological limitations of previous work, focusing on person-specific neural reward networks (and their associations with sensation seeking) in women with CAH and their unaffected sisters in order to inform future research questions and approaches that are most likely to reveal organizational hormone effects on brain structure and function.

Constructing Craving: Applying the Theory of Constructed Emotion to Urge States.

Craving (a strong desire to ingest a substance or engage in an activity) is an important topic of study in the field of psychology. Along with being a key symptom of addiction, craving is a potent source of motivation for a wide range of appetitive behaviors. In this article, I offer a perspective regarding the nature of craving that is rooted in the theory of constructed emotion, a contemporary model of how emotions are created by the brain. According to this perspective, craving states emerge when the brain makes predictions that categorize sensory inputs as an instance of craving based on prior experience and the context in which the inputs occur. Using the theory of constructed emotion as a guiding framework, I review various lines of evidence that provide support for this idea. In addition, I offer recommendations for future research that stem from the hypothesis that instances of craving are constructed by the brain in an experience-dependent and situation-specific manner.

Pilot randomized controlled trial evaluating the effect of random nicotine delivery on cigarettes per day and smoke exposure.

BACKGROUND: Many smokers report attempting to quit each year, yet most relapse, in part due to exposure to smoking-related cues. It is hypothesized that extinction of the cue-drug association could be facilitated through random nicotine delivery (RND), thus making it easier for smokers to quit. The current study aimed to evaluate the effects of RND on smoking cessation-related outcomes including cigarettes per day (CPD) and exhaled carbon monoxide (CO). METHODS: Participants were current smokers (>9 CPD) interested in quitting. Novel trans-mucosal, orally dissolving nicotine films, developed by Bionex Pharmaceuticals, were used in the study. The pharmacokinetic profile of these films was assessed in single (Experiment 1) and multiple-dose (Experiment 2) administrations prior to the smoking cessation study (Experiment 3). In Experiment 3, participants were randomized 1:1:1 to recieve 4 nicotine films per day of either: placebo delivery (0 mg), steady-state delivery (2 mg), or random nicotine delivery (RND) (0 mg or 4 mg). After two weeks, participants were advised to quit (target quit date, TQD) and were followed up 4 weeks later to collect CPD and CO and to measure dependence (Penn State Cigarette Dependence Index; PSCDI) and craving (Questionnaire of Smoking Urges; QSU-Brief). Means and frequencies were used to describe the data and repeated measures ANOVA was used to determine differences between groups. RESULTS: The pharmacokinetic studies (Experiment 1 and 2) demonstrated that the films designed for this study delivered nicotine as expected, with the 4 mg film delivering a nicotine boost of approximately 12.4 ng/mL across both the single and the multiple dose administration studies. The films reduced craving for a cigarette and were well-tolerated, overall, and caused no changes in blood pressure or heart rate. Using these films in the cessation study (Experiment 3) (n = 45), there was a significant overall reduction in cigarettes smoked per day (CPD) and in exhaled CO, with no significant differences across groups (placebo, steady-state, RND). In addition, there were no group differences in dependence or craving. Adverse events included heartburn, hiccups, nausea, and to a lesser extent, vomiting and anxiety and there were no differences across groups. CONCLUSION: Overall, this pilot study found that RND via orally dissolving films was feasible and well tolerated by participants. However, RND participants did not experience a greater reduction in self-reported CPD and exhaled CO, compared with participants in the steady-state and placebo delivery groups. Future studies to evaluate optimal RND parameters with larger sample sizes are needed to fully understand the effect of RND on smoking cessation-related outcomes.

A method to delineate de novo missense variants across pathways prioritizes genes linked to autism.

Genotype-phenotype relationships shape health and population fitness but remain difficult to predict and interpret. Here, we apply an evolutionary action method to de novo missense variants in whole-exome sequences of individuals with autism spectrum disorder (ASD) to unravel genes and pathways connected to ASD. Evolutionary action predicts the impact of missense variants on protein function by measuring the fitness effect based on phylogenetic distances and substitution odds in homologous gene sequences. By examining de novo missense variants in 2384 individuals with ASD (probands) compared to matched siblings without ASD, we found missense variants in 398 genes representing 23 pathways that were biased toward higher evolutionary action scores than expected by random chance; these pathways were involved in axonogenesis, synaptic transmission, and neurodevelopment. The predicted fitness impact of de novo and inherited missense variants in candidate genes correlated with the IQ of individuals with ASD, even for new gene candidates. Taking an evolutionary action method, we detected those missense variants most likely to contribute to ASD pathogenesis and elucidated their phenotypic impact. This approach could be applied to integrate missense variants across a patient cohort to identify genes contributing to a shared phenotype in other complex diseases.

Flavor and product messaging are the two most important drivers of electronic cigarette selection in a choice-based task.

Electronic cigarette use-vaping-is increasingly popular. Various product factors may influence an individual's choice of e-cigarette. To provide an evidence base for e-cigarette regulation, a better understanding of the role different product attributes play in product preferences is needed. Here, we used conjoint analysis to quantify different factors that influence e-cigarettes choices, including flavors, nicotine level, customizability, or use of e-cigarettes to manage appetite/food craving. Young adults completed a set of choice-based conjoint tasks online. Choice Based Conjoint analysis (CBC) was used to determine utility scores for each attribute. Young adults (n = 587) who vaped at least once per week were included in analyses; gender differences were explored. Flavor was the most important attribute (48.1%), followed by product messaging (21.0%) and nicotine level (15.3%). Within flavor, confectionery and fruit flavors had the highest utility scores, while classic menthol and tobacco flavors had the lowest. Men and women differed in flavors, nicotine levels, and product messaging that appealed most. Among young adults who vape weekly, flavor is the most important factor in e-cigarette preferences. Gender also factors into e-cigarette preferences, especially for preferred nicotine level. Understanding why individuals choose particular e-cigarette products will help inform public health efforts and policy making.

Harnessing the paradoxical phenotypes of APOE ɛ2 and APOE ɛ4 to identify genetic modifiers in Alzheimer's disease.

The strongest genetic risk factor for idiopathic late-onset Alzheimer's disease (LOAD) is apolipoprotein E (APOE) ɛ4, while the APOE ɛ2 allele is protective. However, there are paradoxical APOE ɛ4 carriers who remain disease-free and APOE ɛ2 carriers with LOAD. We compared exomes of healthy APOE ɛ4 carriers and APOE ɛ2 Alzheimer's disease (AD) patients, prioritizing coding variants based on their predicted functional impact, and identified 216 genes with differential mutational load between these two populations. These candidate genes were significantly dysregulated in LOAD brains, and many modulated tau- or ß42-induced neurodegeneration in Drosophila. Variants in these genes were associated with AD risk, even in APOE ɛ3 homozygotes, showing robust predictive power for risk stratification. Network analyses revealed involvement of candidate genes in brain cell type-specific pathways including synaptic biology, dendritic spine pruning and inflammation. These potential modifiers of LOAD may constitute novel biomarkers, provide potential therapeutic intervention avenues, and support applying this approach as larger whole exome sequencing cohorts become available.

The feasibility of an in-scanner smoking lapse paradigm to examine the neural correlates of lapses.

Quitting smoking is notoriously difficult. Models of nicotine dependence posit that strength of cognitive control contributes to maintaining smoking abstinence during smoking cessation attempts. We examine the role for large-scale functional brain systems associated with cognitive control in smoking lapse using a novel adaption of a well-validated behavioral paradigm. We use data from 17 daily smokers (five females) after 12 h of smoking abstinence. Participants completed up to 10 sequential 5-min functional magnetic resonance imaging (fMRI) runs, within a single scanning session. After each run, participants decided whether to stay in the scanner in order to earn additional money or to terminate the session in order to smoke a cigarette (i.e., lapse) and forego additional monetary reward. Cox regression results indicate that decreased segregation of the default mode system from the frontoparietal system undermines the ability to resist smoking. This study demonstrates the feasibility of modifying an established behavioral model of smoking lapse behavior for use in the neuro imaging environment, and it provides initial evidence that this approach yields valuable information regarding fine-grained, time-varying changes in patterns of neural activity in the moments leading up to a decision to smoke. Specifically, results lend support to the hypothesis that the time-varying interplay between large-scale functional brain systems associated with cognitive control is implicated in smoking lapse behavior.

Neural correlates of working memory's suppression of aversive olfactory distraction effects.

Human cognitive performance is often disrupted by distractions related to aversive stimuli and affective states, but, paradoxically, there is also evidence to suggest that high working memory demands reduce the impact of aversive distraction. Previous empirical work suggests this latter effect occurs because working memory demands reduce attention to off-task processes, but the brain regions that mediate this effect remain uncertain. The current study utilizes a novel distraction manipulation involving unpleasant odorants to identify neural structures that buffer performance from aversive distraction under high working memory demands, and to clarify their connectivity in this context. Twenty-one healthy young adults (12 women) completed a verbal n-back task under two levels of load and were concurrently exposed to either room air or aversive odorants. Three brain regions displayed increases in neural responses to olfactory distractors under high load only; the left dorsolateral prefrontal cortex, the left ventrolateral prefrontal cortex and right cerebellar Crus I. Of these regions, only the ventrolateral prefrontal cortex also displayed context-specific connectivity with a region thought to be involved in off-task processes: the dorsomedial prefrontal cortex. Overall, results suggest that, under high working memory demands, areas of the prefrontal cortex and cerebellum shield cognition from aversive distraction, potentially through interactions with brain structures involved in off-task processes.

Very Light Daily Smoking in Young Adults: Relationships Between Nicotine Dependence and Lapse.

INTRODUCTION: Very light daily smoking is increasingly common among young adults. Evidence suggests that levels of nicotine dependence vary significantly among young adults who engage in very light daily smoking. However, the links between dependence and clinically relevant outcomes (eg, lapse) in this population remain unclear. The goal of this study was to address this gap by evaluating how well different nicotine dependence scales predict lapse behavior among very light daily smoking young adults. AIMS AND METHODS: Very light daily smokers (1-5 cigarettes/day) aged 18-25 participated in an initial laboratory session, during which nicotine dependence was assessed using four commonly used measures: the FagerstrÓ§m Test for Cigarette Dependence (FTCD), the Hooked On Nicotine Checklist (HONC), the Transdisciplinary Tobacco Use Research Centers (TTURC) Nicotine Dependence Inventory, and the Wisconsin Inventory of Smoking Dependence Motives (WISDM). After a baseline period, eligible participants (n = 40) completed a 10-day abstinence incentive period in which they attempted to refrain from smoking to earn monetary rewards. Cox proportional hazards models were used to test whether dependence predicted days to first lapse. RESULTS: FTCD scores significantly predicted days to lapse, as did scores on the FTCD item assessing time to first cigarette of the day (TTFC). No other dependence measures predicted time to lapse. Both the FTCD and TTFC continued to independently predict time to lapse after controlling for smoking frequency and duration. CONCLUSIONS: The FTCD may be a particularly useful tool for capturing clinically meaningful variability in nicotine dependence among young adults who engage in very light daily smoking. IMPLICATIONS: This is the first study to directly link self-reported nicotine dependence with the ability to achieve and maintain abstinence among very light daily smoking young adults. The results may aid clinicians in selecting among variable measures of nicotine dependence when assessing and treating this population.